150 results on '"Wu, Zhenyu"'
Search Results
102. Experimental investigation on the damage accumulation mechanism of 3D orthogonal woven composites under repeated low-velocity impacts.
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Ying, Zhiping, Chen, Haiyang, Zhu, Zebin, Wu, Zhenyu, Shi, Lin, and Cheng, Xiaoying
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WOVEN composites , *ENERGY levels (Quantum mechanics) , *LAMINATED materials , *CARBON fibers , *MATERIAL plasticity , *FIBROUS composites - Abstract
• Experimental study of the repeated low-velocity impacts of various fiber structures. • 3D woven composites mainly dissipate impact energy through fiber breakage. • 3D orthogonal woven composites mainly show vertical crack paths. • The durability of 3D woven composites under high-energy impact is improved. • The structural integrity of the 3D orthogonal woven composites is high. This paper presents an experimental investigation into the response of carbon fiber reinforced composites with various fiber architectures to repeated low-velocity impacts. Mechanical response diagrams, including repetition numbers and damage morphologies of the composite samples, are provided. Varied energy levels (20 J, 35 J, 50 J) and impact numbers (up to 30th) are considered to induce perforated damage in the composite samples. It is found that the mechanical responses of the composite samples under repeated impact events exhibit distinct characteristics in terms of impact threshold and stiffness degradation. The 2D unidirectional (2DUD) laminated composite sample exhibits a high impact threshold during impact events but stiffness rapidly decays after an initial substantial decline. The 2D plain woven (2DPW) laminated composite sample accumulates impact damage at both high and low levels, resulting in a gradual stiffness decrease during impact events. In addition, the 3D orthogonal woven (3DOW) composite sample demonstrates a higher impact threshold with its stiffness gradually decreasing under high-level impacts. In contrast, both 2DUD and 2DPW composite samples exhibit extensive plastic deformation of the resin matrix with minimal fiber fracture, enabling efficient dissipation of impact energy. Conversely, the 3DOW composite sample primarily dissipates impact energy through fiber fracture. Additionally, it is noteworthy that while both 2DUD and 2DPW composites demonstrate enhanced robustness against repeated impacts at low-energy levels, a significant improvement in durability is observed specifically for the 3DOW composite under high-energy level impacts. [ABSTRACT FROM AUTHOR]
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- 2024
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103. Improved Path Planning for Indoor Patrol Robot Based on Deep Reinforcement Learning.
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Zheng, Jianfeng, Mao, Shuren, Wu, Zhenyu, Kong, Pengcheng, and Qiang, Hao
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DEEP learning , *REINFORCEMENT learning , *REWARD (Psychology) , *MACHINE learning , *ROBOTS , *PROBLEM solving - Abstract
To solve the problems of poor exploration ability and convergence speed of traditional deep reinforcement learning in the navigation task of the patrol robot under indoor specified routes, an improved deep reinforcement learning algorithm based on Pan/Tilt/Zoom(PTZ) image information was proposed in this paper. The obtained symmetric image information and target position information are taken as the input of the network, the speed of the robot is taken as the output of the next action, and the circular route with boundary is taken as the test. The improved reward and punishment function is designed to improve the convergence speed of the algorithm and optimize the path so that the robot can plan a safer path while avoiding obstacles first. Compared with Deep Q Network(DQN) algorithm, the convergence speed after improvement is shortened by about 40%, and the loss function is more stable. [ABSTRACT FROM AUTHOR]
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- 2022
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104. Effect of carbon/Kevlar asymmetric hybridization ratio on the low-velocity impact response of plain woven laminates.
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Wang, Mingling, Pan, Zhongxiang, Wu, Zhenyu, and Ying, Zhiping
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IMPACT response , *POLYPHENYLENETEREPHTHALAMIDE , *LAMINATED materials , *CARBON fibers , *HYBRID materials , *BRITTLE fractures , *PLANT hybridization - Abstract
• Advantages of asymmetric hybridization on impact resistance and resilience. • Rules of external damage area and internal crack volume distribution. • Damage mechanism of carbon/Kevlar hybridization laminates. The ply structure has a significant effect on the impact resistance and failure behavior of composite laminates. In this paper, carbon/Kevlar hybrid fabric reinforcements were prepared with different Kevlar ratio (0%, 25%, 50%, 75%, 100%) by replacing carbon fabric plies on the non-impact side by Kevlar plies. The low-velocity impact tests for all configurations were carried out under 15 J and 25 J energy respectively. The results show that the maximum deflection, impact duration, impact absorption energy and absorption energy efficiency of hybrid laminates increased with the Kevlar hybrid ratio, whereas the peak force presented a decreasing trend, which indicates that the adding of Kevlar layer makes the laminates more ductile than non-hybrid carbon structure. The damage mechanism of the carbon fiber ply was brittle fiber fracture, resin cracking and resin shedding, while the fibers pull-out and tows splitting was found in Kevlar ply. The critical structural damages start from the non-impact side and evolve to the impact side. And the rules of internal crack volume distribution with Kevlar plies are consistent with the trend of external damage area on the non-impact side. It is suggested that in order to take into account the peak strength and excellent structural resilience, Kevlar asymmetric-hybrid ratio of 25% is the most appropriate. The reason is that an appropriate small ratio of Kevlar cushion ply can not only effectively avoid the tensile fracture at non-impact side happened in the non-hybrid carbon structure, but also withstand enough impact load by maintaining a high carbon fiber content. [ABSTRACT FROM AUTHOR]
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- 2021
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105. MOF-derived cobalt nanoparticles in silicon suboxide-based anodes for enhanced lithium storage.
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Chen, Yueying, Huang, Mianying, Deng, Guangfa, Wu, Chunlei, Zhong, Hao, Zeb, Akif, Lin, Xiaoming, Wu, Yongbo, Wu, Zhenyu, Xu, Zhiguang, and Cai, Yuepeng
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METAL nanoparticles , *ELECTRIC conductivity , *NANOPARTICLES , *ENERGY density , *MOLECULAR self-assembly , *ANODES - Abstract
[Display omitted] • Self-assembly by electrostatic interaction between silane and MOF ligand. • The activation mechanism of electrochemical inert metal Co in SiO x materials was investigated. • The catalytic action of atomic Co site activates Si O bond and Li O bond to increase SiO x capacity and coulomb efficiency. • High mechanical strength and high conductivity Co nanoparticles enhance the conductivity and cycling stability of SiO x. The ultra-high theoretical capacity of silicon-based (Si) materials makes them promising anode materials for high energy density lithium-ion batteries. Unfortunately, the dramatic volume change (∼300%) and low electrical conductivity of silicon have severely hindered the commercial use of silicon anodes. Silicon suboxide (SiO x) is one of the ideal candidates for high energy density batteries due to its reduced swelling and lower cost as compared to silicon. However, it remains a huge challenge to address the low conductivity, low (initial) coulombic efficiency and apparent volume effects of SiO x. In this paper, SiO x /Co@C composite anode materials loaded with metal Co nanoparticles were uniformly and efficiently prepared by using 3-aminopropyl triethoxysilane (APTES) as silicon source and Co-MOF as Co source via molecular self-assembly strategy. The experimental results and density functional theory (DFT) calculation showed that the catalytic action of embedded Co nanoparticles had activated the silico-oxygen bond of SiO x and the irreversible product Li 2 O, thereby improving the initial coulombic efficiency (ICE) and enhancing the reversible capacity. At the same time, the metal Co with mechanical rigidity and electrical conductivity alleviated the volume fluctuation during alloying and improved the charge transfer capacity and ion transport rate of the composite. When compared with SiO x @C anodes, SiO x /Co@C-600 composites showed higher initial CE, superior cyclic stability and good rate performance. In particular, the successful matching of the anode with the lithium iron phosphate (LFP) cathode in full cell systems validated the possibility of its practical application. This work provides important insights into the application of Si-based materials in lithium-ion battery electrode materials and the development of high energy density batteries. [ABSTRACT FROM AUTHOR]
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- 2024
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106. A novel deformation monitoring model for high arch dams using impulse response-based equivalent temperature and machine learning-aided separate modeling.
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Li, Zefa, Yin, Chuan, Chen, Rengui, Wu, Zhenyu, Chen, Jiankang, and Lu, Xiang
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ARCH dams , *ARCH model (Econometrics) , *DEEP learning , *IMPULSE response , *MACHINE learning , *WATER levels , *TEMPERATURE - Abstract
• A temperature component is given by theoretical inference and parameter optimization. • Separate modeling technique is proposed based on ICEEMDAN and clustering analysis. • The ET-SMT-DELM model is established by a multi-output deep extreme learning machine. • The proposed model has high accuracy, credibility and interpretability. The anatomy of service status through health monitoring models is essential to long-term structural safety. Since deformation is the intuitive representation of the dam's operating condition, it is crucial to investigate the deformation monitoring model with high accuracy and strong interpretability for the safety management of high arch dams. A novel deformation monitoring model is proposed by incorporating impulse response-based equivalent temperature (ET) and machine learning-aided separate modeling technique (SMT). This methodology has three main sources of novelty. First, the impulse response-based equivalent temperature and corresponding temperature component are derived from heat transfer and temperature convolution theories. Then, the model parameters are identified by an improved firefly algorithm. Second, the components in the monitored displacement are progressively stripped out by clustering analysis, separation under equal water level conditions, and a robust signal decomposition technique. Third, the separated deformation components and environmental factors are modeled by the multi-output deep extreme learning machine (DELM) with autoencoder, and the monitoring model ET-SMT-DELM is thus established. The world's highest arch dam is selected to illustrate the proposed model, and the prediction accuracy, early warning performance, component shares, and impulse response mechanism are comprehensively investigated by comparing with several typical baseline models. The results show that the overfitting of the proposed model is reduced, and the prediction and early warning performance is significantly improved. The resulting temperature impulse response function and component shares imply that the interpretability of the model is also enhanced. [ABSTRACT FROM AUTHOR]
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- 2024
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107. Improved XCT image automatic segmentation for quantitative characterization of the meso-morphological features in the damaged braided composite fabric.
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Zheng, Kehong, Cao, Xiaoqi, Jiang, Zheyang, Chen, Hao, Qiu, Bingjing, Lu, Wenpan, Wu, Chenglie, Pan, Zhongxiang, and Wu, Zhenyu
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IMAGE segmentation , *BRAIDED structures , *MECHANICAL behavior of materials , *AXIAL loads , *COMPOSITE materials , *COMPUTED tomography - Abstract
Accurately identifying various meso-morphological features and sub-phases within the damaged braided composite fabric is crucial for assessing the mechanical properties of composites under complex loading conditions and different processing parameters. However, obtaining 3D reconstructions that can be quantitatively analyzed is still a challenge, primarily due to the low contrast of the meso-morphological features (yarn tow and matrix crack networks). In this work, a new data enhancement algorithm is proposed to generate a realistic-looking artificial training dataset for enriching the information of the meso-morphological features. Then, the effect of various training networks and training parameters (the size of real and hybrid training dataset, number of epochs) on segmentation performance were examined. Finally, the meso-morphological features were statistically analyzed to accurately evaluate the mechanical properties of the composite material. The work presented here provides an effective tool that enables the quantitative analysis of the dynamic crack evolution process under the axial load of the composite materials. [Display omitted] [ABSTRACT FROM AUTHOR]
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- 2024
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108. The stellar metallicity distribution in intermediate-latitude fields with BATC and SDSS data.
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Peng, Xiyan, Du, Cuihua, and Wu, Zhenyu
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DISTRIBUTION of stars , *SPECTRAL energy distribution , *ASTRONOMICAL photometry , *FLUCTUATIONS (Physics) , *DISKS (Astrophysics) , *GALAXY formation , *STELLAR populations , *COSMOLOGICAL distances - Abstract
ABSTRACT Based on Beijing-Arizona-Taiwan-Connecticut (BATC) and Sloan Digital Sky Survey (SDSS) photometric data, we adopt the spectral energy distribution (SED) fitting method to evaluate the metallicity distribution for ∼40 000 main-sequence stars in the Galaxy. According to the derived photometric metallicities of these sample stars, we find that the metallicity distribution shifts from metal-rich to metal-poor with the increase of distance from the Galactic Centre. The mean metallicity is about −1.5 ± 0.2 dex in the outer halo and −1.3 ± 0.1 dex in the inner halo and smoothly decreases from −0.4 to −0.8 in the interval 0 < r≤ 5 kpc. A fluctuation in mean metallicity with Galactic longitude can be found in the interval 4 < r≤ 8 kpc. There is a vertical abundance gradient d[Fe/H]/d z∼−0.21 ± 0.05 dex kpc−1 for the thin disc ( z≤ 2 kpc). At a distance 2 < z≤ 5 kpc, where thick-disc stars dominate, the gradient is about −0.16 ± 0.06 dex kpc−1; this can be interpreted as a mixture of stellar populations with different mean metallicities at all z levels. The vertical metallicity gradient is −0.05 ± 0.04 dex kpc−1 for the halo ( z > 5 kpc), so there is little or no metallicity gradient in the halo. [ABSTRACT FROM AUTHOR]
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- 2012
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109. Fast Dynamic IR-Drop Prediction Using Machine Learning in Bulk FinFET Technologies.
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Huang, Pengcheng, Ma, Chiyuan, and Wu, Zhenyu
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MACHINE learning , *INTEGRATED circuits , *FORECASTING , *STATISTICAL correlation - Abstract
IR-drop is a fundamental constraint by almost all integrated circuits (ICs) physical designs, and many iterations of timing engineer change order (ECO), IR-drop ECO, or other ECO are needed before design signoff. However, IR-drop analysis usually takes a long time and wastes so many resources. In this work, we develop a fast dynamic IR-drop predictor based on a machine learning technique, XGBoost, and the prediction method can be applied to vector-based and vectorless IR-drop analysis simultaneously. Correlation coefficient is often used to characterize the symmetry of prediction data and golden data, and our experiments show that the prediction correlation coefficient is more than 0.96 and the average error is no more than 1.3 mV for two industry designs, which are of 2.4 million and 3.7 million instances, respectively, and that the analysis is speeded up over 4.3 times compared with the IR-drop analysis by commercial tool, Redhawk. [ABSTRACT FROM AUTHOR]
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- 2021
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110. Prediction and Risk Factors for Prognosis of Cirrhotic Patients with Hepatic Encephalopathy.
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Peng, Ying, Wei, Qinglin, Liu, Yun, Wu, Zhenyu, Zhang, Hongjia, Wu, Hongbo, and Chai, Jin
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HEPATIC encephalopathy , *BLOOD urea nitrogen , *RECEIVER operating characteristic curves , *INTERNATIONAL normalized ratio , *PROGNOSIS - Abstract
Background and Aims. Hepatic encephalopathy (HE) is characterized by recurrence and poor quality of life. Acute-on-chronic liver failure (ACLF) mainly occurs in patients with chronic liver diseases and often presents with HE. Several predictive models have been proposed to predict the outcomes of these patients. Our study is aimed at identifying associated risk factors and the prognostic accuracies of predictive models in HE patients with or without ACLF. Methods. Patients with liver cirrhosis were retrospectively enrolled. Risk factors were evaluated by multivariate regression analyses. The predictive capabilities of models were calculated using the receiver operating characteristic (ROC) curve analyses and compared by the DeLong tests. Outcomes were defined as in-hospital mortality, HE severity, and ACLF occurrence. Results. In multivariate regression analyses, serum biomarkers neutrophil and total bilirubin (TBIL) were independently correlated with in-hospital death. Alanine aminotransferase (ALT) and blood urea nitrogen (BUN) were independent serum biomarkers associated with HE severity. Hemoglobin, TBIL, BUN, and international normalized ratio (INR) were significant indicators associated with ACLF incidence. For prediction of in-hospital mortality, Child-Pugh was superior to the others in the whole patients, while NLR showed the best capability in the ACLF group. Conclusion. In cirrhotic patients present with HE, BUN is a risk factor associated with HE severity and ACLF incidence. Child-Pugh and NLR scores may be effective prognosticators in patients with HE. [ABSTRACT FROM AUTHOR]
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- 2021
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111. Inhibition of polo-like kinase 1 (PLK1) facilitates reactivation of gamma-herpesviruses and their elimination.
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Biswas, Ayan, Zhou, Dawei, Fiches, Guillaume N., Wu, Zhenyu, Liu, Xuefeng, Ma, Qin, Zhao, Weiqiang, Zhu, Jian, and Santoso, Netty G.
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EPSTEIN-Barr virus , *AIDS , *CELL death , *KAPOSI'S sarcoma-associated herpesvirus , *HIV-positive persons , *HIV infections , *NEGATIVE regulatory factor - Abstract
Both Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV) establish the persistent, life-long infection primarily at the latent status, and associate with certain types of tumors, such as B cell lymphomas, especially in immuno-compromised individuals including people living with HIV (PLWH). Lytic reactivation of these viruses can be employed to kill tumor cells harboring latently infected viral episomes through the viral cytopathic effects and the subsequent antiviral immune responses. In this study, we identified that polo-like kinase 1 (PLK1) is induced by KSHV de novo infection as well as lytic switch from KSHV latency. We further demonstrated that PLK1 depletion or inhibition facilitates KSHV reactivation and promotes cell death of KSHV-infected lymphoma cells. Mechanistically, PLK1 regulates Myc that is critical to both maintenance of KSHV latency and support of cell survival, and preferentially affects the level of H3K27me3 inactive mark both globally and at certain loci of KSHV viral episomes. Furthremore, we recognized that PLK1 inhibition synergizes with STAT3 inhibition to efficiently induce KSHV reactivation. We also confirmed that PLK1 depletion or inhibition yields the similar effect on EBV lytic reactivation and cell death of EBV-infected lymphoma cells. Lastly, we noticed that PLK1 in B cells is elevated in the context of HIV infection and caused by HIV Nef protein to favor KSHV/EBV latency. Author summary: KSHV is a large double-stranded DNA virus belonging to human gamma-herpesviruses and capable of establishing the long-term persistent infection, which causes cancers under immunocompromised states, such as acquired immunodeficiency syndrome (AIDS). There are currently still no effective therapies to specifically treat KSHV-associated tumors, nor eliminate its persistent infection. In this study, we illustrated that PLK1 is upregulated by KSHV, which in return suppresses KSHV lytic infection. We further demonstrated that PLK1 is a novel host target that can be inhibited pharmacologically to benefit the viral oncolysis for promotion of KSHV lytic reactivation and elimination of KSHV-positive lymphoma cells, particularly for people living with HIV (PLWH). PLK1 inhibitors also exerted the similar effect on EBV that is the other member of human gamma-herpesvirus. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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112. Research and Application of Critical Failure Paths Identification Method for Dam Risk Analysis.
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He, Kun, Pei, Liang, Lu, Xiang, Chen, Jiankang, and Wu, Zhenyu
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DAM failures , *RISK assessment , *FAULT trees (Reliability engineering) , *ANALYTIC hierarchy process , *DAMS , *CRITICAL path analysis - Abstract
Dam is an important part of the national infrastructure, and its safety has been widely concerned. Risk identification of dams plays a significant role in risk assessment and control. Finding out some critical failure paths through adopting timely measures can help reduce the risk occurrence probability effectively. This paper develops an identification method based on the credibility and the interval analytic hierarchy process (IAHP) methods, namely, consistency and difference-based interval analytic hierarchy process (CDB-IAHP) method, to identify the critical failure paths of dams exactly considering the dynamic cognition degree of decision-makers. Based on the fault tree analysis (FTA) method, the framework and analysis for critical failure paths identification of a gravity dam and an Earth-rockfill dam are conducted and made. The results show that the critical failure paths obtained by the proposed method are in line with the statistical data, and the importance of disaster causing factors has some difference with the traditional method. Additionally, some engineering and nonengineering measures are suggested to reduce the impact of potential failure paths. The applications demonstrate that the proposed method shows good applicability for risk analysis and critical failure path mining of dams. [ABSTRACT FROM AUTHOR]
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- 2020
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113. Detection of transformer winding faults using FRA and image features.
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Zhou, Lijun, Jiang, Junfei, Zhou, Xiangyu, Wu, Zhenyu, Lin, Tong, and Wang, Dongyang
- Abstract
Frequency response analysis (FRA) is a widely used approach for detecting winding faults in a transformer. Appropriate and quantitative FRA features will help to improve the accuracy of fault diagnosis. In this study, a novel FRA interpretation including new image features is proposed based on the image processing technique. First, winding faults of different windings are simulated in a test autotransformer and the FRA curves are measured under various faults. Then frequency region division method and image processing technique are first applied to the measured FRA curves. The area ratio and centroid deviation in different frequency regions are calculated through a novel algorithm. Finally, the image features are used as the inputs to support vector machine model. Additionally, three different parametric optimisation algorithm are compared during the training process. The results show that the particle swarm optimisation and image feature exhibit best performance for identifying winding faults. [ABSTRACT FROM AUTHOR]
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- 2020
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114. FRA modelling for diagnosing axial displacement of windings in traction transformers.
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Zhou, Lijun, Jiang, Junfei, Li, Wei, Wu, Zhenyu, Gao, Shibin, Guo, Lei, and Liu, Hongwen
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The windings of a traction transformer are always be threatened by the fluctuation of the load. Frequency response analysis (FRA) is regarded as the most effective method to diagnose the winding deformation. Appropriate FRA modelling method may help to predict typical winding faults for large transformers. The existing model usually simplify dozens of winding disks into several disks, it is applicable when analysing small displacement. However, when the disks between windings are seriously misplaced, the conventional model may not be suitable. This study presents an improved lumped parameter circuit model considering intersection capacitances and mutual inductance between windings. The feasibility of the proposed model is verified based on a 10 kV test transformer. Finally, the model is applied for a 220 kV traction transformer, the variation of parameters and features are analysed for axial displacement of different windings. The results show that the axial displacement may lead to increase of resonance frequency and decrease of amplitude. The low‐frequency band (1–30 kHz) may be regarded as visible features for diagnosing axial displacement of H winding and the middle frequency band (50–200 kHz) may be a characteristic band for diagnosing axial displacement of T winding. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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115. An improved dataset augmentation approach for deep learning-based XCT images segmentation in layered composite fabric.
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Zheng, Kehong, Chen, Hao, Wu, Chenglie, Zhang, Xin, Ying, Zhiping, Wang, Zhenyu, Wu, Zhenyu, Pan, Zhongxiang, and Qiu, Bingjing
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DEEP learning , *IMAGE segmentation , *WOVEN composites , *FIBROUS composites , *COMPOSITE materials , *COMPUTED tomography - Abstract
Accurate 3D representations of multiphase layered composite fabric, including distinguish and label the pores, matrices, warp and weft yarns, can assist in understanding and ultimately improving composite material design performance. In this work, a new data enhancement algorithm is proposed to generate realistic-looking artificial learning datasets for expanding the datasets. Then, we demonstrate how supervised, the Swin Transformer approach can help to realize accurate segmentation of low-resolution and poor-contrast fabric datasets by populating databases with real and artificial learning datasets. Most of the pixels were correctly identified and the boundaries of the yarn could be identified clearly, except for some spots and a few merged boundaries. The work presented here provides an effective tool that can be widely used in semantic segmentation for various composite materials (woven composites, fiber-reinforced composites, short-fiber materials, etc.), which enables higher-precision reconstruction of fiber-composites and significant reduction in dataset processing time, and provides a route to generating artificial learning dataset. [ABSTRACT FROM AUTHOR]
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- 2023
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116. A novel non-enzymatic H2O2 sensor using ZnMn2O4 microspheres modified glassy carbon electrode.
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Li, Yuanyuan, Tang, Li, Deng, Dongmei, Ye, Jinhong, Wu, Zhenyu, Wang, Jinhua, and Luo, Liqiang
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CARBON electrodes , *MICROSPHERES , *ELECTROCHEMICAL sensors , *SCANNING electron microscopy , *X-ray spectroscopy , *RAMAN spectroscopy , *DETECTORS - Abstract
• ZnMn 2 O 4 microspheres/GCE displayed high electrocatalytic activity towards H 2 O 2 reduction. • The non-enzymatic sensor exhibited wide linear range of 0.02 ˜ 15 mM with high sensitivity of 277.1 mA mM−1 cm−2. • The proposed H 2 O 2 sensor showed excellent anti-interference ability and stability. With a facile solvothermal technique, ZnMn 2 O 4 microspheres were synthesized in this work, which were used as enzyme mimics for the electrocatalytic reduction of H 2 O 2. The morphology, crystal phase and structure of the ZnMn 2 O 4 microspheres underwent characterization under X-ray diffraction spectroscopy, Raman spectroscopy, energy-dispersive spectroscopy, and scanning electron microscopy. The synthesized ZnMn 2 O 4 microspheres showed an average diameter of 2 μm with great crystallinity, and exhibited excellent catalytical activity towards H 2 O 2 electroreduction in alkaline media. The glassy carbon electrode modified by ZnMn 2 O 4 microspheres showed a linear amperometric response for H 2 O 2 in a wide concentration range of 0.02 ˜ 15 mM with detection limit of 0.13 μM under the optimized conditions. Besides, the sensor proposed here was successfully used to determine H 2 O 2 in milk, suggesting that ZnMn 2 O 4 microspheres can be used for non-enzymatic electrochemical sensor applications. [ABSTRACT FROM AUTHOR]
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- 2019
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117. High vacuum distillation for low-sulfur biodiesel production: From laboratory to large scale.
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Xie, Qinglong, Cai, Li, Xia, Fan, Liang, Xiaojiang, Wu, Zhenyu, Liu, Yuanqing, Li, Xiaohua, Lu, Meizhen, Nie, Yong, and Ji, Jianbing
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TRANSESTERIFICATION , *DISTILLATION , *BOILING-points , *VACUUM , *ECONOMIC research - Abstract
Desulfurization is important to the enhancement of biodiesel quality. In this study, the effects of reactant and catalyst addition and operations conducted on sulfur content at each stage during the biodiesel preparation process were examined. Based on the results of sulfide qualification and quantification, a high vacuum distillation method was developed to remove the sulfides in crude biodiesel. Biodiesel was separated into different fractions based on the boiling point and the sulfur content of each fraction was determined. Experimental results showed that most sulfides were distilled out with light and heavy fractions. Intermediate fraction was separated from the other fractions, resulting in high quality biodiesel with low sulfur content. The total yield of distillation fractions with sulfur content lower than 10 ppm reached 84.1%. A set of distillation facility with capacity of 10 m3/h was designed and developed accordingly for large-scale tests. The yield of low-sulfur biodiesel was around 83%, close to that obtained in the laboratory studies. In addition, economic analysis showed that the distillation facility can make revenue of more than $1.8 million per year, indicating that high vacuum distillation is economically feasible and promising for biodiesel desulfurization, especially in industrial application. Image 104946 • A high vacuum distillation method was proposed to remove sulfides in crude biodiesel. • Sulfides in crude biodiesel were qualitatively and quantitatively analyzed. • The total yield of biodiesel with sulfur content lower than 10 ppm was 84.1%. • Distillation facility with capacity of 10 m3/h was developed for large-scale tests. • The process is economically feasible for low-sulfur biodiesel production. [ABSTRACT FROM AUTHOR]
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- 2019
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118. Measurement and correlation of the density, viscosity and vapor pressure of fatty acid 2-ethyhexyl esters.
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Zheng, Ting, Fang, Jiaojiao, Xie, Qinglong, Wu, Zhenyu, Lu, Meizhen, Xia, Fan, Deng, Dongshun, Nie, Yong, and Ji, Jianbing
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VAPOR pressure , *VISCOSITY , *FATTY acids , *ESTERS , *EVAPORATION (Chemistry) - Abstract
Highlights • The measurement of density, viscosity and vapor pressure for three typical fatty acid 2-ethylhexyl esters were carried out. • Correlation of the density and viscosity of fatty acid 2-ethylhexyl esters using empirical temperature dependent equations. • The experimental vapor pressures were well correlated with the Antoine and Wager equations. • The Clausius-Clapeyron equation was used to calculate the molar evaporation enthalpy. Abstract Fatty acid 2-ethylhexyl esters are used for the eco-friendly production of biolubricant. There are several reports on their synthesis, but thermodynamics and transport data of these compounds are lacking. Herein, density and viscosity of palmitic acid 2-ethylhexyl ester, stearic acid 2-ethylhexyl ester and soya oil 2-ethylhexyl esters in the temperature range of T = (298.18–368.15) K at atmospheric pressure were measured and the vapor pressure in the temperature range of T = (476.95–500.85, 477.05–498.05, 477.75–500.05) K was determined. The obtained experimental data were correlated using temperature-dependence correlation equations, and the correlation coefficients of all the equations were over 0.999. In order to examine the reliability of the data, the GCVOL group method was used to evaluate densities for these fatty acid 2-ethylhexyl esters with the maximum relative deviation of −1.34%. The experimental viscosity data of synthesized 2-ethylhexyl esters were compared with those of lauric acid 2-ethylhexyl ester, palmitic acid n-octyl ester and oleic acid 2-ethylhexyl ester from previous studies. In addition, the molar enthalpy of vaporization at the mean temperature of the experimental range was calculated for the first time using the Clausius-Clapeyron equation. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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119. Dual stabilized architecture of hollow Si@TiO2@C nanospheres as anode of high-performance Li-ion battery.
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Lu, Bing, Ma, Bingjie, Deng, Xinglan, Wu, Bing, Wu, Zhenyu, Luo, Jing, Wang, Xianyou, and Chen, Gairong
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LITHIUM-ion batteries , *SILICON , *TITANIUM dioxide , *ANODES , *CARBON , *X-ray photoelectron spectroscopy - Abstract
The hollow Si nanospheres modified by the mechanically robust titanium dioxide (TiO 2 ) shell and the uniform carbon layer are intentionally designed and successfully prepared as the anode active material of high performance lithium-ion batteries. The effects of the robust TiO 2 shell and the uniform carbon layer on the structure and electrochemical performances for the Si@TiO 2 @C nanospheres are studied in detail by X-ray photoelectron spectroscopy, transmission electron microscopy, X-ray diffraction and charge/discharge tests. The results show that the hollow structure of the Si core can spontaneously absorb the huge volume expansion stress, the robust TiO 2 shell is used as a compact fence to promote the expansion towards the interior of the Si cavity instead of the exterior in the processes of charge/discharge, and the uniform carbon layer can effectively enhance the electrical conductivity and further control the integrity and stability of the well-wrapped core-shell-shell framework. Typically, the resultant hollow Si@TiO 2 @C nanospheres exhibit a high initial discharge capacity of 2557.1 mAh g −1 with coulombic efficiency of 86.06% as well as a large recuperative discharge capacity of 1270.3 mAh g −1 after 250 cycles at 1 A g −1 with a mean coulombic efficiency of 99.53%. Therefore, the hollow Si@TiO 2 @C nanospheres prepared by one-step sol-gel coating process show outstanding electrochemical properties and are considered as a prospective candidate to the adhibitions of the anode material for new generation power LIBs. [ABSTRACT FROM AUTHOR]
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- 2018
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120. Device-Free Vehicle Speed Estimation With WiFi.
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Wang, Jie, Tong, Jingyu, Gao, Qinghua, Wu, Zhenyu, Bi, Sheng, and Wang, Hongyu
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INTELLIGENT transportation systems , *WIRELESS Internet , *ELECTRONICS in transportation , *TECHNOLOGICAL innovations , *INTERNET access - Abstract
Vehicle networks is a promising technique, which could provide ubiquitous wireless access for vehicles and realize intelligent transportation. Motivated by the recent advances on device-free wireless sensing, this paper explores a novel technique, which could estimate the speed of a vehicle by analyzing its influence on surrounding wireless signals from roadside wireless infrastructures, such as WiFi. This technique could enable vehicle networks with new moving speed sensing ability and evolve it into a large-scale sensing network, which could monitor the traffic status seamlessly. To achieve this goal, in this paper, we propose and formulate a model to characterize the relationship between the phase and amplitude measurements and the vehicle speed. Based on the model, we develop an efficient method to detect the vehicle and estimate its speed accordingly using the frequency-domain information involved in the spectrogram. We carry out extensive experiments utilizing commodity WiFi. The experimental results reveal that the proposed method could estimate the speed with an error of less than 2.6 km/h, which meets the United Nations regulation for speedometer. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
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121. Open hole tensile behavior of plain woven carbon/glass hybrid composites.
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Yu, Jiajia, Pan, Zhongxiang, Cai, Qimao, Zhang, Fa, and Wu, Zhenyu
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HYBRID materials , *GLASS composites , *CARBON composites , *GLASS fibers , *ULTIMATE strength , *CARBON fibers , *FIBROUS composites - Abstract
• Hybridization of glass fiber into carbon composite presents toughening effect. • Infrared thermography accurately evaluates the progressive damage. • Off-axial tensile properties are more sensitive than on-axial for hybrid composites. • The quick crack propagation in hybrid composites is prevented. • Damage of interior carbon fiber layers can be restrained through hybridization. Hybrid composites are increasingly attractive for advanced engineering applications. In this study, the open-hole tensile (OHT) properties and failure mechanism of plain woven carbon fiber, glass fiber, and carbon/glass hybrid fiber composites under on-axis (0°) and off-axis (45°) loads were investigated through experimental and numerical approaches. The progressive damage was characterized by high-speed infrared thermography. The numerical simulation presented a good explanation on the damage development. It indicates that the carbon/glass hybrid composites exhibited significant improvement in failure strain and toughness compared to pure carbon fiber composite. With the insertion of glass fiber layers, the failure modes of hybrid structures were modified and quick propagation of cracks was prevented. Once the cracking on their carbon layers had initiated there was an increase in damage to glass fiber layers showing the transfer of stress from carbon layers to glass layers. Similar mechanical properties were reached among sandwich-like hybrid samples in on-axis tension, but much greater properties can be achieved when the carbon fiber at the interior layers of the hybrid specimens under off-axis load. Since glass fiber with great ductility was laminated as the surface layers in hybridization, resulting in less delamination and higher ultimate strength in 45○ off-axis tension. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2023
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122. Assessing the global productive efficiency of Chinese banks using the cross-efficiency interval and VIKOR.
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Wu, Meiqin, Li, Changhong, Fan, Jianping, Wang, Xiangyu, and Wu, Zhenyu
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BANKING industry , *ECONOMIC development , *BUSINESS success , *ECONOMIC indicators , *DATA envelopment analysis - Abstract
The banking industry plays an essential role in China's economic growth, and the assessment of bank efficiency has attracted increasing interest in the past two decades. Given that the data envelopment analysis cross-efficiency method can provide a more reliable reference set, a large number of studies targeting performance evaluation and its applications adopt this method. Few studies, however, address the issue of the non-uniqueness of weights in cross-efficiency evaluation. Whereas, this paper proposes a cross-efficiency interval considering all weighting schemes along with a VIKOR aggregate model to gauge the universal productive efficiency of 16 major Chinese commercial banks of China and rank them for the period of 2007–14. Specifically, we use the cross-efficiency interval to generate the global performance of each bank based on internal and external assessment while using VIKOR to compare the solution with the attitude index which ranks all of the banks. The results indicate that the cross-efficiency interval can provide more information than the traditional DEA model, that the banking system efficiency of China has been improved during the study period, especially for SOBs; that JSBs are more efficient compared with SOBs; and the efficiency gap narrowed during the study period. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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123. Analysis of Factors Associated with the Ocular Features of Congenital Cataract Children in the Shanghai Pediatric Cataract Study.
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He, Wenwen, Sun, Ting, Yang, Jin, Qin, Guoyou, Wu, Zhenyu, Zhu, Xiangjia, and Lu, Yi
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CATARACT , *EYE , *EYE abnormalities , *FACTOR analysis , *SEX distribution , *RETROSPECTIVE studies , *TERTIARY care , *CHILDREN - Abstract
Purpose. To investigate the ocular features of children with congenital cataract in a tertiary referral eye center in East China. Methods. We retrospectively reviewed the clinical data of congenital cataract children who underwent cataract surgery between April 2009 and April 2014 at the Eye and ENT Hospital of Fudan University and identified factors associated with the axial length (AXL) and corneal curvature (K value). Results. We included 493 children, 210 with unilateral and 283 with bilateral cataract. The mean AXL was 22.03 ± 1.97 mm and the mean K value was 43.61 ± 1.86 D. Age showed a linear correlation with AXL in unilateral cataract eyes and a logarithmic correlation with AXL in bilateral cataract eyes (both P<0.001). AXL was longer and the K value was smaller (both P<0.01) in boys than in girls after adjusting for age and cataract laterality. AXL was longer in unilateral cataract eyes than in bilateral cataract eyes after adjusting for age and gender (P=0.004). In children with unilateral cataract, AXL was significantly longer in the affected eye than in the contralateral eye (P<0.001). Conclusion. Age, gender, and cataract laterality together contribute to the development of ocular features of congenital cataract children, especially for AXL. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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124. Lymphocyte count or percentage: which can better predict the prognosis of advanced cancer patients following palliative care?
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Weiwei Zhao, Peng Wang, Huixun Jia, Menglei Chen, Xiaoli Gu, Minghui Liu, Zhe Zhang, Wenwu Cheng, Zhenyu Wu, Zhao, Weiwei, Wang, Peng, Jia, Huixun, Chen, Menglei, Gu, Xiaoli, Liu, Minghui, Zhang, Zhe, Cheng, Wenwu, and Wu, Zhenyu
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LYMPHOCYTES , *CANCER prognosis , *PALLIATIVE treatment , *CANCER patient medical care , *LEUKOCYTE count , *TUMOR classification , *TUMOR treatment , *PROGNOSIS , *TUMORS , *COMORBIDITY , *PROPORTIONAL hazards models , *KAPLAN-Meier estimator , *LYMPHOCYTE count - Abstract
Background: The lymphocytes played an important role in the natural history of cancer. The aim of this study was to explore the prognostic value of lymphocyte count and percentage for survival in advanced cancer patients receiving palliative care.Methods: A retrospective review of clinicopathological data from 378 consecutive advanced cancer patients and 106 extended follow-up patients treated with palliative care was conducted. Kaplan-Meier curves and multivariate cox regression analyses were used to evaluate the relationships of peripheral lymphocyte count (LC) and lymphocyte to white blood cell ratio (LWR) with overall survival (OS).Results: The median values for pretreatment LC and LWR were 1.1 (IQR, 0.8 ~ 1.5 × 109/L) and 0.138 (IQR, 0.086 ~ 0.208). The median survival times across LWR quartiles were 19, 47, 79, and 101 days (P < 0.001). Multivariate analysis indicated that patients in the highest quartiles of LC and LWR had an HR of 1.082 (95% CI 0.777 ~ 1.506, P = 0.642) and 0.466 (95% CI 0.328 ~ 0.661, P < 0.001), respectively, compared with patients in the lowest quartiles. Furthermore, only the dynamic changes of LWR were confirmed as an independent prognostic factor for overall survival during the follow-up (HR = 0.396, 95% CI 0.243 ~ 0.668; P = 0.001), as were primary tumor site and ECOG. No effect was observed for the dynamic changes of LC.Conclusions: Our findings demonstrate that measurement of the dynamic changes of LWR prior to treatment and during follow-up may represent a simple and new powerful prognostic factor for patients with advanced cancer, unlike measurement of LC. As a bedside marker of immune status, the prognostic role of LWR should be further evaluated in prospective studies. [ABSTRACT FROM AUTHOR]- Published
- 2017
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125. Impact damage characteristics of braided/unidirectional hybridization laminates when impacted on different sides.
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Ying, Zhiping, Li, Jianhao, Xiang, Zhong, Hu, Xudong, and Wu, Zhenyu
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LAMINATED materials , *FINITE element method , *IMPACT response , *FAILURE mode & effects analysis , *PEAK load - Abstract
• The structural hybridization effect on low-velocity impact response of braided/unidirectional (UD) laminates was investigates. • Continuum shell finite element models based on the anisotropic constitutive relationship of braided and UD plies were established to reveal the damage onset and propagation. • The extensive delamination formed rapidly when impacted on the fabric side. • The damage characterized by severe fiber breakage occurs at the impact site when impacted on UD ply side. This work investigated the structural hybridization effect on the low-velocity impact response of braided/unidirectional(UD) laminate. Two groups of hybridization laminates, namely interleaving and clustering groups, were manufactured. The impact performance of the specimens was characterized by combining dropping testbench, optical camera and ultra-sound detector. A continuum shell finite element model was established to reveal the progressive damage behavior of hybridization laminate. The specimen in the interleaving group presented overwhelming performance than that in the clustering group. The impact side effect on failure modes was discussed in detail. When impacted on the braided fabric side, extensive delamination formed on the edge of the specimen due to bending deformation. It further resulted in-plane crushing failure of UD sub-laminate. In contrast, severe fiber breakage occurs at the impact site due to combination stress of tensile and shear when impacted on UD side. Therefore, the fabric-impacted specimen exhibits better impact resistance than that impacted on UD side with respect to higher peak load and lower absorbed energy. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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126. Assessing the adequacy of lymph node yield for different tumor stages of colon cancer by nodal staging scores.
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Zhenyu Wu, Guoyou Qin, Naiqing Zhao, Huixun Jia, Xueying Zheng, Wu, Zhenyu, Qin, Guoyou, Zhao, Naiqing, Jia, Huixun, and Zheng, Xueying
- Subjects
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COLON cancer patients , *LYMPH node diseases , *PREOPERATIVE care , *DISEASE prevalence , *CLINICAL epidemiology , *ADENOCARCINOMA , *COLON tumors , *LYMPH nodes , *METASTASIS , *TUMOR classification , *STATISTICAL models , *DIAGNOSIS - Abstract
Background: According to the current official guidelines, at least 12 lymph nodes (LNs) are qualified as an adequate sampling for colon cancer patients. However, patients evaluated with less nodes were still common in the United States, and the prevalence of positive nodal disease may be under-estimated because of the false-negative assessment. In this study, we present a statistical model that allows preoperative determination of the minimum number of lymph nodes needed to confirm a node-negative disease with certain confidence.Methods: Adenocarcinoma colon cancer patients with stage T1-T3, diagnosed between 2004 and 2013, who did not receive neoadjuvant therapies and had at least one lymph node pathologically examined, were extracted from the Surveillance, Epidemiology and End Results (SEER) database. A beta binomial distribution was used to estimate the probability of an occult nodal disease is truly node-negative as a function of total number of LNs examined and T stage.Results: A total of 125,306 patients met study criteria; and 47,788 of those were node-positive. The probability of falsely identifying a patient as node-negative decreased with an increasing number of nodes examined for each stage, and was estimated to be 72% for T1 and T2 patients with a single node examined and 57% for T3 patients with a single node examined. To confirm an occult nodal disease with 90% confidence, 3, 8, and 24 nodes need to be examined for patients from stage T1, T2, and T3, respectively.Conclusions: The false-negative rate of diagnosed node negative, together with the minimum number of examined nodes for adequate staging, depend preoperatively on the clinical T stage. Predictive tools can recommend a threshold on the minimum number of examined nodes regarding to the favored level of confidence for each T stage. [ABSTRACT FROM AUTHOR]- Published
- 2017
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127. Dynamic temperature field and drilling damage mechanism of plain woven carbon/glass hybrid composites.
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Yu, Jiajia, Pan, Zhongxiang, Ye, Wei, Li, Qinchuan, and Wu, Zhenyu
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HYBRID materials , *GLASS composites , *ISOTHERMAL temperature , *TEMPERATURE distribution , *CONCRETE fatigue , *PLAINS - Abstract
Hybrid structures are increasingly important in joints of composite components. For carbon, glass, and bilateral carbon/glass hybrid composites, a thermal-mechanical characterization experimental study was implemented to explore the hybrid effect on the drilling temperature evolutions and damage mechanism. Infrared thermography was applied to analyze the temperature distribution from the side and exit surface of the composites. The results indicate that the hybrid structure generated an abrupt change of thrust force during drilling the carbon/glass interfacial region and the maximum peak force was induced in 5C5G specimen. The temperature isothermal on the side surface of hybrid composites gradually evolved into a trapezoidal shape. The variations of hole positions on the plain fabric structure can affect the temperature generation and heat transfer. The carbon layer can prevent bending deformation and act as a support in drilling the last layer of 5G5C and showed better performance. Severe damage was induced for the less mechanical strength in the glass layer and low heat dissipation of exit material leading to concentrated heat. Accumulated high temperature reduced the bonding strength between the fiber and resin, and thus the debonding, matrix smearing and resin strips occurred. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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128. Highly electro-responsive ionic soft actuator based on graphene nanoplatelets-mediated functional carboxylated cellulose nanofibers.
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Wang, Fan, Huang, Daliang, Li, Qinchuan, Wu, Yujiao, Yan, Bo, Wu, Zhenyu, and Park, Sukho
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BIONICS , *ACTUATORS , *NANOFIBERS , *FLEXIBLE electronics , *CELLULOSE , *CELLULOSE fibers , *GRAPHENE - Abstract
Electro-responsive ionic soft actuators have attracted increasing interest owing to the promising applications for soft robots, biomimetic robots, active medical devices, flexible electronics, and wearable devices. However, existing ionic actuators still need a technology breakthrough for larger bending strain, faster response, and excellent actuation durability. Herein, we report a novel highly electro-responsive ionic actuator based on functional carboxylated cellulose nanofibers (CCNF) by doping with ionic liquid (IL) and graphene nanoplatelets (GN). The proposed CCNF-IL-GN actuator demonstrated a large tip displacement of 15.71 mm (peak-to-peak) at 2.0 V with 0.1 Hz, faster rise time (2.9s), broad frequency bandwidth (0.1–3.0 Hz), markedly reduced phase delay, and long actuation durability (98.6% retention for 3 h) without actuation response distortion, all of which were due to the fast-easy ion migration and massive charge transport ability of the designed ionically crosslinked electrolyte membrane, resulting from the strong ionic interactions and crosslinking of CCNF nanofibers with IL and GN. Furthermore, we investigated the actuator's bionic applications such as the bionic flower, bionic finger, and bionic window. These results elucidate the great potential of the designed CCNF-IL-GN actuators for bionic robots, soft robots, wearable electronics, and biomedical active devices. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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129. Policies of promoting entrepreneurship and Angel Investment: Evidence from China.
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Li, Changhong, Shi, Yulin, Wu, Cong, Wu, Zhenyu, and Zheng, Li
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ENTREPRENEURSHIP , *ANGEL investors , *INVESTMENTS , *GOVERNMENT policy , *ECONOMIC development - Abstract
Using a sample of angel investments in China from 1994 to 2013, we examine effects of government policies that are favorable to start-ups on angel investment. Our findings show that positive effects of these policies on the amounts of angel investments are more significant in provinces with higher economic growth than those in provinces with lower economic growth. Policies that promote entrepreneurship affect the returns from high-amount angel investments more than those from low-amount ones. These findings indicate that such policies help to shape the new venture market in China and guide angel investors in making more efficient investments. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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130. Reduction of Nuak1 Decreases Tau and Reverses Phenotypes in a Tauopathy Mouse Model.
- Author
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Lasagna-Reeves, Cristian A., de Haro, Maria, Hao, Shuang, Park, Jeehye, Rousseaux, Maxime W.C., Al-Ramahi, Ismael, Jafar-Nejad, Paymaan, Vilanova-Velez, Luis, See, Lauren, De Maio, Antonia, Nitschke, Larissa, Wu, Zhenyu, Troncoso, Juan C., Westbrook, Thomas F., Tang, Jianrong, Botas, Juan, and Zoghbi, Huda Y.
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PHENOTYPES , *GENETICS , *NEURODEGENERATION , *ANIMAL models in research , *PHOSPHORYLATION - Abstract
Summary Many neurodegenerative proteinopathies share a common pathogenic mechanism: the abnormal accumulation of disease-related proteins. As growing evidence indicates that reducing the steady-state levels of disease-causing proteins mitigates neurodegeneration in animal models, we developed a strategy to screen for genes that decrease the levels of tau, whose accumulation contributes to the pathology of both Alzheimer disease (AD) and progressive supranuclear palsy (PSP). Integrating parallel cell-based and Drosophila genetic screens, we discovered that tau levels are regulated by Nuak1, an AMPK-related kinase. Nuak1 stabilizes tau by phosphorylation specifically at Ser356. Inhibition of Nuak1 in fruit flies suppressed neurodegeneration in tau-expressing Drosophila , and Nuak1 haploinsufficiency rescued the phenotypes of a tauopathy mouse model. These results demonstrate that decreasing total tau levels is a valid strategy for mitigating tau-related neurodegeneration and reveal Nuak1 to be a novel therapeutic entry point for tauopathies. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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131. High strain-rate compression behavior of woven CF/PEEK thermoplastic composites at the glassy state and high-elastic state.
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Pan, Zhongxiang, Yang, Chengcai, Huang, Shuwei, Wang, Mingling, Wu, Zhenyu, and Gu, Bohong
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MECHANICAL loads , *WOVEN composites , *STRAIN rate , *FAILURE mode & effects analysis , *AIR flow - Abstract
• Air flow heating without tank is reliable and effective for drastic impact loads. • Mechanics of woven CF/PEEK is more sensitive to temperature than strain rate. • Ultimate service temperature significantly influences impact dynamic behavior. • Brittle-Loose transition of damage modes were found from glassy to high-elastic state. • Failure modes at high temperature were verified by micro-scale characterization. A reliable hot air-flow heating approach is creatively carried out for high strain rate tests without environment tank. The out-of-plane and in-plane compression of carbon fiber reinforced polyetheretherketone (CF/PEEK) woven composites are investigated from 400 to 4000/s at the glassy state and high-elastic state. The real-time and in-situ deformation and failure process of the composite specimens under the extreme thermo-mechanical loads are successfully captured, which can reflect the impact dynamic behavior of the material near the ultimate service temperature. Empirical laws for mechanical index of the woven composites are given. The results reveal that the thermal softening effect outperforms the strain-rate strengthening effect. For out-of-plane impact at low strain rates, damage mode transitions from the interface and matrix cracking at glassy state to the "parallel" shear and fiber extrusion at high-elastic state. Under high strain rates, it reveals the "fragmented" shear mode at glassy state. For in-plane impact, the temperature effect leads to the failure mode changing from the delamination and local shear to the mixed feature of kinking bands, delamination, and multiple-band shear with "bulge" behavior. And the multiple-band shear and delamination are more likely to occur along the in-plane direction as the strain rate increased. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2022
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132. Symmetric and asymmetric intercalation effect on the low-velocity impact behavior of carbon/Kevlar hybrid woven laminates.
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Wang, Mingling, Pan, Zhongxiang, Ying, Zhiping, and Wu, Zhenyu
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POLYPHENYLENETEREPHTHALAMIDE , *LAMINATED materials , *FIBROUS composites , *IMPACT strength , *CARBON fibers , *CARBON - Abstract
• Advantages of symmetric intercalation hybridization on impact strength and resilience. • Correlation of apparent damage area index and internal damage volume data. • Damage mechanism of symmetric and asymmetric carbon/Kevlar structures. Hybrid fiber composite laminates with the same materials, manufacturing methods and molding processes may present different mechanical behaviors. In this paper, the effect of intercalation sequence on the mechanical performance of carbon/Kevlar plain laminates were studied. According to different intercalation methods, the hybrid layout was divided into symmetric and asymmetric configurations. It is found that the symmetric intercalation structures (KCCK and CKKC) possess better load-bearing and resilience capacity compared with asymmetric structures (CCKK and CKCK), even better than pure carbon structure (CCCC) under high energy impact. The impact damage volume of symmetric specimens was significantly smaller than that of asymmetric specimens by quantitative micro-CT analysis. The apparent damage index (d f and d r) can be used to estimate the internal damage data (d CT , H and V). KCCK, a typical symmetric sandwich-like structure, presented the most slight damage among all symmetric and asymmetric configurations, with shear cracks observed at the brittle carbon fiber core layers, while the delamination cracks between Kevlar-carbon interlayers were away from the central damaged region. In CKCK, interlaminar cracks were formed at each carbon-Kevlar interlayers, which shared and relieved the primary interlaminar crack at the core layers compared with CCKK. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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133. Effect of TongXie-YaoFang on Cl− and HCO3- Transport in Diarrhea-Predominant Irritable Bowel Syndrome Rats.
- Author
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Lu, Xiaofang, Zhang, Shengsheng, Yang, Cheng, Wang, Zhengfang, Zhao, Luqing, Wu, Zhenyu, and Xie, Jing
- Subjects
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ANIMAL experimentation , *BIOLOGICAL models , *DIARRHEA , *HERBAL medicine , *INTESTINAL mucosa , *IRRITABLE colon , *CHINESE medicine , *RATS , *SEROTONIN - Abstract
TongXie-YaoFang (TXYF) can effectively alleviate the symptoms of diarrhea-predominant irritable bowel syndrome (D-IBS) patients. However, the curative mechanism has not been fully clarified. The study was designed to investigate the effect of TXYF on the colonic ion transport induced by serotonin (5-HT) in D-IBS rats. A method of multiple stress (neonatal maternal separation (NMS) combined with restraint stress (RS)) was used to induce the D-IBS model. The model rats were randomly divided into two groups: NMS + RS group and TXYF-formula group, and the normal control (no handling) rats were classified as NH group. In the NMS + RS group, the change of short-circuit current (ΔIsc) induced by 5-HT was lower than that in the NH and TXYF-formula groups. After removing of the extracellular Cl− or HCO3- or basolateral Na+ or blocking the cystic fibrosis transmembrane conductance regulator (CFTR), Na+-K+-2Cl− cotransporter (NKCC), Na+-HCO3- cotransporter, Cl-/HCO3- exchanger, K+ channel, or Na+/K+-ATPase, respectively, there was no difference in 5-HT-induced ΔIsc among the three groups. These data suggest that TXYF can regulate 5-HT-induced Cl− and HCO3- secretion, possibly mediated by the combined action of CFTR, NKCC, Na+-HCO3- cotransporter, Cl-/HCO3- exchanger, K+ channel, and Na+/K+-ATPase. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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- View/download PDF
134. Competitive sorption of As(V) and Cr(VI) on carbonaceous nanofibers.
- Author
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Cheng, Wencai, Ding, Congcong, Wang, Xiangxue, Wu, Zhenyu, Sun, Yubing, Yu, Shuhong, Hayat, Tasawar, and Wang, Xiangke
- Subjects
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SORPTION , *NANOFIBERS , *CARBON nanofibers , *SPECTRUM analysis , *OXIDATION-reduction reaction - Abstract
The competitive sorption of As(V) and Cr(VI) on the novel and uniform carbonaceous nanofibers (CNFs) was investigated in single/binary-metal systems. The presence of Cr(VI) showed a greater inhibitory effect on the sorption of As(V) in binary As–Cr system, especially at higher Cr(VI) concentrations. The maximum sorption capacities of Cr(VI) and As(V) on CNFs in single-metal systems at pH 5.0 and 303 K were calculated as 2.36 and 0.67 mmol/g, respectively, by Langmuir equation. XPS results demonstrated that only As(V) species was present at the CNFs surface, whereas both Cr(VI) and Cr(III) species existed on the CNFs surfaces, suggesting the partially reduction of Cr(VI) to Cr(III) by CNFs. According to the macroscopic and spectroscopic analysis, both inner-sphere and outer-sphere surface complexation contributed to the sorption process of Cr(VI), in contrast to the electrostatic outer-sphere sorption of As(V) on CNFs. The inner-sphere Cr complexes might arise from the covalent bonding between Cr(III) and oxygen-containing functional groups of CNFs. The findings herein highlight the higher chemical affinity of CNFs for Cr(VI) relative to As(V), as a consequence of the redox reaction of the strongly toxic Cr(VI) with CNFs. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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- View/download PDF
135. Study on leakage dissolution around the dam foundation of the Qingju Hydropower Station and its engineering influence on the dam.
- Author
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Zhou, Zhengjun, Chen, Jiankang, Li, YanLing, He, Peng, Zhang, Hai, Dai, Hong, and Wu, Zhenyu
- Subjects
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DAM design & construction , *ENGINEERING geology , *MECHANICAL deformation measurement , *CRYSTALS , *GROUNDWATER research - Abstract
Leakage dissolution is one of the potential threats to the long-term operating safety of a dam. The aim of this paper is to analyze the characteristics of leakage dissolution around the dam foundation of Qingju Hydropower Station and evaluate its engineering influence based on laboratory testing and in situ monitoring. Comparative analysis of water samples in 20 representative positions shows that the bedrock of the dam foundation has been enduring obvious dissolution under the effects of the groundwater. In situ monitoring data of displacement and leakage during the period from 2005 to 2013 indicates that there has been no excessive deformation, obvious uneven settlement, or concentration leakage in these nine years, and; therefore, the leakage dissolution of the dam foundation has not resulted in critical danger to the safety of dam so far. However, with an annual amount of gypsum dissolution discharged by the drainpipes of about $$ 1.82 \times 10^{5}\,{\rm kg} $$ , long-term leakage dissolution may be hazardous, besides the higher content of SO than normal in the groundwater of the dam foundation caused by leakage dissolution may invoke some crystal corrosion and decrease the durability of the concrete structures. To guarantee the long-term safety of the dam, implementing grouting is proposed to prevent dissolution or slow down the dissolution rate on the basis of real-time monitoring and feedback. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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136. Architecture and performance of Si/C microspheres assembled by nano-Si via electro-spray technology as stability-enhanced anodes for lithium-ion batteries.
- Author
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Li, Wangwu, Peng, Jiao, Li, Hui, Wu, Zhenyu, Chang, Baobao, Guo, Xiaowei, Chen, Gairong, and Wang, Xianyou
- Subjects
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MICROSPHERES , *LITHIUM-ion batteries , *ANODES , *ELECTRIC batteries , *LITHIUM ions , *BUFFER layers , *ELECTRON diffusion , *CHEMICAL kinetics - Abstract
• Construct carbon protective shell to alleviate huge volume changes of Si. • Robust carbon framework can effectively maintains the structure integrity. • Carbon buffer layer can offer rich e-/ion channels to improve reaction kinetics. • The SCM electrode exhibited excellent electrochemical performance. Si-based anodes have revealed the potential as the next generation of lithium ion battery anode material, whereas the poor conductivity and huge volume changes during (de)lithiation process of silicon still limit their practical application. Herein, the Si/nitrogen doped carbon layer/carbon framework microspheres (SCM) are designed by nano-Si via electro-spray technology as anodes for lithium ion batteries. It has been found that the SCM consists of individual carbon-coated nano-Si primary particles linked by PAN framework, in which the carbon buffer layer can further absorb the stress of volume changes during charge/discharge process, and the carbon framework carbon framework not only provides fast diffusion path of electron, but also effectively reduces the consumption of electrolyte. Therefore, the initial columbic efficiency (ICE) of SCM anode can reach as high as 72%, and the SCM anode also shows a high specific capacity of 1192 mAh g−1 at 0.2 A g−1 and keeps a reversible capacity of 746 mAh g−1 after 200 cycles, demonstrating the as-designed SCM possesses an high ICE and a good electrochemical performance. This strategy provides a significant inspiration for fabricating high-performance Si/C anode materials of lithium-ion battery. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
137. Combined effects of Fenton peroxidation and CaO conditioning on sewage sludge thermal drying.
- Author
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Liu, Huan, Liu, Peng, Hu, Hongyun, Zhang, Qiang, Wu, Zhenyu, Yang, Jiakuan, and Yao, Hong
- Subjects
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SEWAGE sludge drying , *PEROXIDATION , *LIME (Minerals) , *FENTON'S reagent , *CHEMICAL decomposition , *OXIDATION , *DISSOLUTION (Chemistry) - Abstract
Joint application of Fenton’s reagent and CaO can dramatically enhance sludge dewaterability, thus are also likely to affect subsequent thermal drying process. This study investigated the synergistic effects of the two conditioners on the thermal drying behavior of sewage sludge and the emission characteristics of main sulfur-/nitrogen-containing gases. According to the results, Fenton peroxidation combined with CaO conditioning efficiently promoted sludge heat transfer, reduced the amounts of both free and bound water, and created porous structure in solids to provide evaporation channels, thus producing significant positive effects on sludge drying performance. In this case, the required time for drying was shortened to one-third. Additionally, joint usage of Fenton’s reagent and CaO did not increase the losses of organic matter during sludge drying process. Meanwhile, they facilitated the formation of sulfate and sulfonic acid/sulfone, leading to sulfur retention in dried sludge. Both of Fenton peroxidation and CaO conditioning promoted the oxidation, decomposition, and/or dissolution of protein and inorganic nitrogen in sludge pre-treatment. As a consequence, the emissions of sulfurous and nitrogenous gases from dewatered sludge drying were greatly suppressed. These indicate that combining Fenton peroxidation with CaO conditioning is a promising strategy to improve drying efficiency of sewage sludge and to control sulfur and nitrogen contaminants during sludge thermal drying process. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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- View/download PDF
138. Environmental regulations and innovation for sustainability? Moderating effect of political connections.
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Wu, Bao, Fang, Hanqing, Jacoby, Gady, Li, Geling, and Wu, Zhenyu
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ENVIRONMENTAL regulations , *MODERATES (Political science) , *SUSTAINABILITY , *PRIVATE companies , *CHINESE corporations - Abstract
Companies are subject to both formal regulation pressure from government and informal regulation pressure from other stakeholders to adopt green innovations for sustainability. Using a sample of 4924 private Chinese companies, our empirical study indicates that both formal and informal regulation pressures have a positive effect on green innovation. We also find that political connections positively moderate the effect of formal regulation pressure on green innovation, but negatively moderate the effect of informal regulation pressure on green innovation. • Both formal and informal regulation pressures have a positive effect on green innovation. • Political connections positively moderate the effect of formal regulation pressure on green innovation. • Political connections negatively moderate the effect of informal regulation pressure on green innovation. • Political connections shield local companies from some of the pressures of informal regulation. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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139. The accurate localization of fluorescent nanoparticle - in nu/ nu mice kidney.
- Author
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Yang, Hui, Sun, Cuiji, Jia, Jun, Nie, Guangjun, and Wu, Zhenyu
- Subjects
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NANOPARTICLES , *KIDNEY glomerulus , *NANOSTRUCTURED materials , *KIDNEY blood-vessels , *MOLECULAR probes - Abstract
-, as a green synthesized nanoparticle, is composed of a ferritin nanocage enclosing a pair of nanoclusters inside. Our previous study has demonstrated that - can be an excellent fluorescent probe for whole body imaging of mice with kidney specific targeting. But, the accurate localization of - in kidney is still absent. In the current study, we detected and assessed the cellular and subcellular localization of - in renal cortex and medulla of nu/nu mice after tail vein injection by using Nuance optical system (CRi, Woburn, USA) and inForm intelligent image analysis software based on single cell segmentation. We obtained the fluorescence intensity and cellular location of kidney-targeting - probe in particular cell of renal glomerulus or renal tubules, which provided valuable proofs to clarify the mechanism of - selective enrichment in kidney and the associated metabolic processes. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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140. SHANK3 overexpression causes manic-like behaviour with unique pharmacogenetic properties.
- Author
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Han, Kihoon, Holder Jr, J. Lloyd, Schaaf, Christian P., Lu, Hui, Chen, Hongmei, Kang, Hyojin, Tang, Jianrong, Wu, Zhenyu, Hao, Shuang, Cheung, Sau Wai, Yu, Peng, Sun, Hao, Breman, Amy M., Patel, Ankita, Lu, Hui-Chen, and Zoghbi, Huda Y.
- Subjects
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GENE expression , *BIPOLAR disorder , *HUMAN behavior , *PHARMACOGENOMICS , *NEUROBEHAVIORAL disorders , *DRUG dosage - Abstract
Mutations in SHANK3 and large duplications of the region spanning SHANK3 both cause a spectrum of neuropsychiatric disorders, indicating that proper SHANK3 dosage is critical for normal brain function. However, SHANK3 overexpression per se has not been established as a cause of human disorders because 22q13 duplications involve several genes. Here we report that Shank3 transgenic mice modelling a human SHANK3 duplication exhibit manic-like behaviour and seizures consistent with synaptic excitatory/inhibitory imbalance. We also identified two patients with hyperkinetic disorders carrying the smallest SHANK3-spanning duplications reported so far. These findings indicate that SHANK3 overexpression causes a hyperkinetic neuropsychiatric disorder. To probe the mechanism underlying the phenotype, we generated a Shank3 in vivo interactome and found that Shank3 directly interacts with the Arp2/3 complex to increase F-actin levels in Shank3 transgenic mice. The mood-stabilizing drug valproate, but not lithium, rescues the manic-like behaviour of Shank3 transgenic mice raising the possibility that this hyperkinetic disorder has a unique pharmacogenetic profile. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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- View/download PDF
141. An "inner soft external hard", scratch-resistant, self-healing waterborne poly(urethane-urea) coating based on gradient metal coordination structure.
- Author
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Sheng, Yeming, Wang, Minhui, Zhang, Kangping, Wu, Zhenyu, Chen, Yaxin, and Lu, Xun
- Subjects
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SURFACE coatings , *DYNAMIC mechanical analysis , *ATOMIC force microscopes , *METAL bonding , *ZINC ions , *COORDINATION polymers , *ZINC coating - Abstract
[Display omitted] • A special coating show a stiff surface and strong adhesion to substrate. • Showing good self-healing ability and 4H hardness by strong and weak coordination. • Better self-healing efficiency in humid and hot environments. • An innovative method to prepare "inner soft external hard" coatings. To reduce pollution and maintain sustainable development, environmental friendly waterborne coatings as a replacement for conventional oil-based coatings have drawn lots of attention and been widely studied recently. It is a challenge to overcome the inherited weakness of waterborne coatings including poor scratch-resistance, low hardness and short lifespan. Herein, we have developed a scratch-resistant and self-healing waterborne coating of poly(urethane-urea), which contains a dual metal coordination structure of Zn(II)-carboxyl and Zn(II)-diamidepyridine by using the method of ions penetration. The addition of zinc ions has given dense metal coordination bonds on the coating surface, which has greatly increased the surface hardness (from B to 4H) and scratch-resistance, while the inner layer keeps excellent adhesion (>1.5 MPa) to substrates because of less metal ion penetration to the inner. What's more, the coating exhibits outstanding self-repairing performance, and the repair ability is better under hygrothermal condition. Atomic force microscope (AFM), dynamic mechanical analysis (DMA) and thermal analysis were used to characterize the self-healing and hardening mechanisms of the coatings. These results are expected to provide a useful method to improve the overall strength of waterborne coating. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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- View/download PDF
142. Fabrication of visible-light-driven one-dimensional anatase TiO2/Ag heterojunction plasmonic photocatalyst
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Jiang, Liming, Zhou, Guo, Mi, Jia, and Wu, Zhenyu
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PHOTOCATALYSIS , *MICROFABRICATION , *TITANIUM dioxide , *SILVER catalysts , *HETEROJUNCTIONS , *PLASMONS (Physics) , *SILVER nanoparticles , *METALLIC surfaces - Abstract
Abstract: Visible-light-driven one-dimensional (1D) anatase TiO2/Ag plasmonic photocatalyst was successfully prepared through a facile wet impregnation method. Experimental results indicate that Ag nanoparticles cover on the surface of TiO2 uniformly and the heterogeneous structure is formed efficiently. The obtained 1D anatase TiO2/Ag heterogeneous composites exhibit excellent photocatalytic activity (nearly 100% within 2h) for degradation of 2,4-dichlorophenol in wastewaters, which is ascribed to the suitable particle size of Ag nanoparticles in favor of enhancing the surface plasmon resonance and the heterogeneous structure advantageous of the separation of photogenerated electron–hole pairs. After reusage for ten times, the composites still present high photocatalytic activity, indicating the excellent stability. [Copyright &y& Elsevier]
- Published
- 2012
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143. A novel damage mechanism analysis of integrally braided CFRP and CFRP/Aluminum hybrid composite tube subjected to transverse impact.
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Pan, Zhongxiang, Qiao, Feng, Wang, Mingling, Wu, Zhenyu, and Ying, Zhiping
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ALUMINUM composites , *FAILURE mode & effects analysis , *TUBES , *FAILURE analysis , *ALUMINUM foam , *THERMOGRAPHY - Abstract
[Display omitted] • Integral braiding and near-net forming of CFRP and CFRP/Al hybrid composite tubes. • In-situ and real-time failure mode analysis of CFRP and CFRP/Al composite tube under transverse impact. • Comprehensive effect of braiding angle, locailzed temperature rise, and ductile aluminum on the damage mechanism. High-speed infrared thermography, micro-CT characterization and full-scale mesostructural simulation were jointly applied to reveal the impact deformation and damage mechanism of composite tubes. Two different failure modes, namely the Impact Side Dominated (ISD) and Impact-/Non-impact Side (INIS), were found to have relation with the braiding angle and localized temperature rise. The hybrid effect can not only prevent resin fragmentation in the triangle region at the lateral side and the diamond region at the non-impact side, but also inhibit the CFRP damage development at the lateral and non-impact side. In small-angle braided tube, the impact-side rebound trend of CFRP layer leads to mismatch at the CFRP-Al interface, which results in opening delamination. In large-angle braided tube, the non-impact-side damage plays an important role in further load-bearing capacity. Apart from the structure effect, temperature rise has an effect on composite damage mode by degrading the localized matrix stiffness. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
144. Prediction of residual mechanical properties in flexure-after-impact of woven composite beams through electrical resistance measurement.
- Author
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Cheng, Xiaoying, Gong, Yi, Liu, Yisheng, Wu, Zhenyu, and Hu, Xudong
- Subjects
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WOVEN composites , *IMPACT testing , *FORECASTING , *ACOUSTIC emission , *FLEXURAL modulus , *COMPOSITE construction , *CARBON fiber-reinforced ceramics - Abstract
Low-velocity impact and flexure-after-impact (FAI) tests were performed on 2D plain woven fabric (PWF) and 3D orthogonal woven fabric (OWF) reinforced carbon fibers/epoxy composite beams while the electrical resistance measurement was applied during impact and FAI tests via four-probe technique to study the relations between resistance variation (RV) and residual mechanical properties. The impact tests (from 3 J to 9 J) showed that OWF specimens have better suppression of delamination than PWF, which was also evaluated through thermography and cross-sectional imaging method. Then FAI tests were implemented on impacted specimens while acoustic emission signals were captured. The residual flexural strength and modulus from the FAI tests were normalized by the values of intact specimens and compared with the RV from impact tests. The relations between electrical and mechanical properties revealed that the rise of resistance after the impact is an effective sign that indicates the reduction in the residual flexural strength and modulus of the composite beam. Moreover, the relation between RV and residual modulus is more effective than that with residual strength. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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- View/download PDF
145. Investigation of Heavy-Ion Induced Single-Event Transient in 28 nm Bulk Inverter Chain.
- Author
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Wu, Anquan, Liang, Bin, Chi, Yaqing, and Wu, Zhenyu
- Subjects
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LINEAR energy transfer , *SOFT errors , *HEAVY ions , *INTEGRATED circuits , *PREAMPLIFIERS , *MAGNITUDE (Mathematics) - Abstract
The reliability of integrated circuits under advanced process nodes is facing more severe challenges. Single-event transients (SET) are an important cause of soft errors in space applications. The SET caused by heavy ions in the 28 nm bulk silicon inverter chains was studied. A test chip with good symmetry layout design was fabricated based on the 28 nm process, and the chip was struck by using 5 kinds of heavy ions with different linear energy transfer (LET) values on heavy-ion accelerator. The research results show that in advanced technology, smaller sensitive volume makes SET cross-section measured at 28 nm smaller than 65 nm by an order of magnitude, the lower critical charge required to generate SET will increase the reliability threat of low-energy ions to the circuit, and high-energy ions are more likely to cause single-event multiple transient (SEMT), which cannot be ignored in practical circuits. The transients pulse width data can be used as a reference for SET modeling in complex circuits. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
146. Interlayer contact mechanism of the frictional behavior of glass-fiber woven fabrics and improvements of winding characteristics.
- Author
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Xiang, Zhong, Liu, Yang, Zhou, Xiangqin, Wu, Zhenyu, and Hu, Xudong
- Subjects
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WINDING machines , *TEXTILES , *STATIC friction - Abstract
Interlayer friction is an important factor in producing rolls of glass-fiber woven fabric and strongly depends on the fabric structure and fabric interlayer contact mechanism. This paper investigates the effect of the initial contact state on the fabric/fabric friction coefficient by adjusting dislocations along circumferential and axial directions with a Capstan-based test setup. Results reveal that the maximal friction coefficient is approximately proportional to the height gradient between two adjacent yarns, while the minimal friction coefficient is less sensitive to the fabric structure. Moreover, a dislocation between fabric layers reduces both the maximal static and dynamical friction coefficients, and actively reciprocating a dislocation along the axial direction is an effective way of avoiding the interlayer friction from remaining at a low level. A dislocating mechanism is developed and introduced to a commercial fabric winding machine to verify the effectiveness of the proposed method in improving winding quality. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
147. Changes in distributions of waist circumference, waist-to-hip ratio and waist-to-height ratio over an 18-year period among Chinese adults: a longitudinal study using quantile regression.
- Author
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Qian, Xiwen, Su, Chang, Zhang, Bing, Qin, Guoyou, Wang, Huijun, and Wu, Zhenyu
- Subjects
- *
WAIST-hip ratio , *QUANTILE regression , *WAIST circumference , *LONGITUDINAL method , *DRINKING behavior - Abstract
Background: Little is known about the long-term shifts in distributions of three abdominal-obesity-related indicators, waist circumference (WC), waist-to-hip ratio (WHpR) and waist-to-height ratio (WHtR) among Chinese adults. Traditional mean regression models used in the previous analyses were limited in their ability to capture cross-distribution among effects. The current study aims to describe the shift in distribution of WC, WHpR, and WHtR over a period of 18 years (1993-2011) in China, and to reveal quantile-specific associations of the three indicators with key covariates.Methods: Longitudinal data from seven waves of the China Health and Nutrition Surveys (CHNS) in 1993, 1997, 2000, 2004, 2006, 2009 and 2011 were analyzed. The LMS method was used to illustrate the gender-specific quantile curves of WC, WHtR and WHpR over age. Separate gender-stratified longitudinal quantile regressions were employed to investigate the effect of important factors on the trends of the three indicators.Results: A total of 11,923 participants aged 18-65 years with 49,507 observations were included in the analysis. The density curves of WC, WHtR and WHpR shifted to right and became wider. The three outcomes all increased with age and increased more at upper percentiles. From the multivariate quantile regression, physical activity was negatively associated in both genders; smoking only had a negative effect on male indicators. Education and drinking behavior both had opposite effects on the three indicators between men and women. Marital status and income were positively associated with the shifts in WC, WHtR and WHpR in male and female WC, while urbanicity index had a positive effect on three outcomes in men but inconsistent effect among female outcomes.Conclusions: The abdominal-obesity related indicators of the Chinese adults experienced rapid growth according to our population-based, age- and gender-specific analyses. Over the 18-year study period, major increases in WC, WHtR and WHpR were observed among Chinese adults. Specifically, these increases were greater at upper percentiles and in men. Age, physical activity, energy intake, drinking, smoking, education, income and urbanicity index were associated with elevated abdominal obesity indicators, and the effects differed among percentiles and between genders. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
148. Nomogram-based parameters to predict overall survival in a real-world advanced cancer population undergoing palliative care.
- Author
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Zhao, Weiwei, He, Zhiyong, Li, Yintao, Jia, Huixun, Chen, Menglei, Gu, Xiaoli, Liu, Minghui, Zhang, Zhe, Wu, Zhenyu, and Cheng, Wenwu
- Subjects
- *
CANCER patient psychology , *CONFIDENCE intervals , *PALLIATIVE treatment , *SURVIVAL analysis (Biometry) , *SURVIVAL , *RETROSPECTIVE studies , *STATISTICAL models , *DESCRIPTIVE statistics ,TUMOR prognosis - Abstract
Background: Although palliative care has been accepted throughout the cancer trajectory, accurate survival prediction for advanced cancer patients is still a challenge. The aim of this study is to identify pre-palliative care predictors and develop a prognostic nomogram for overall survival (OS) in mixed advanced cancer patients. Methods: A total of 378 consecutive advanced cancer patients were retrospectively recruited from July 2013 to October 2015 in one palliative care unit in China. Twenty-three clinical and laboratory characters were collected for analysis. Prognostic factors were identified to construct a nomogram in a training cohort (n = 247) and validated in a testing cohort (n = 131) from the setting. Results: The median survival time was 48.0 (95% CI: 38.1–57.9) days for the training cohort and 52.0 (95% CI: 34.6–69.3) days for the validation cohort. Among pre-palliative care factors, sex, age, tumor stage, Karnofsky performance status, neutrophil count, hemoglobin, lactate dehydrogenase, albumin, uric acid, and cystatin-C were identified as independent prognostic factors for OS. Based on the 10 factors, an easily obtained nomogram predicting 90-day probability of mortality was developed. The predictive nomogram had good discrimination and calibration, with a high C-index of 0.76 (95% CI: 0.73–0.80) in the development set. The strong discriminative ability was externally conformed in the validation cohort with a C-index of 0.75. Conclusions: A validated prognostic nomogram has been developed to quantify the risk of mortality for advanced cancer patients undergoing palliative care. This tool may be useful in optimizing therapeutic approaches and preparing for clinical courses individually. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
149. Murine exposure to gold nanoparticles during early pregnancy promotes abortion by inhibiting ectodermal differentiation.
- Author
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Yang, Hui, Du, Libo, Wu, Guangjun, Wu, Zhenyu, and Keelan, Jeffrey A.
- Subjects
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PREGNANCY , *GOLD nanoparticles , *ABORTION , *EMBRYONIC stem cells , *POLYETHYLENE glycol - Abstract
Background: Gold nanoparticles (AuNPs) have been widely studied for biomedical applications, although their safety and potential toxicity in pregnancy remains unknown. The aim of this study is to explore the effect of AuNPs maternal exposure at different gestational ages on fetal survival and development, as well as the potential mechanism of AuNPs affecting embryos and fetuses. Methods: Thirty nm polyethylene glycol (PEG)-coated AuNPs (A30) were administered to pregnant mice via intravenous injection (5 μg Au/g body weight) over three days at either early or late pregnancy. Fetal abortion rate and morphological development in E16.5 were then detected in detail. The pregnant mice physiological states with A30 exposure were examined by biochemical, histological or imaging methods; and materno-fetal distribution of gold elements was assayed by electron microscopy and mass spectrometry. Murine embryonic stem cells derived embryoid-bodies or neuroectodermal cells were treated with A30 (0.0025 to 0.25 μg Au/mL) to examine A30 effects on expression levels of the germ differentiation marker genes. Tukey's method was used for statistical analysis. Results: Exposure to A30 during early (A30E) but not late (A30L) pregnancy caused a high abortion rate (53.5%), lower fetal survival rate and abnormal decidualization compared with non-exposed counterparts. The developmental damage caused by A30 followed an "all-or-nothing" pattern, as the non-aborted fetuses developed normally and pregnancies maintained normal endocrine values. A30 caused minor impairment of liver and kidney function of A30E but not A30L mice. TEM imaging of fetal tissue sections confirmed the transfer of A30 into fetal brain and live as aggregates. qPCR assays showed A30 suppressed the expression of ectodermal, but not mesodermal and endodermal differentiation markers. Conclusions: These results illustrate that maternal A30 exposure in early pregnant results in A30 transfer into embryonic tissues, inhibiting ectodermal differentiation of embryonic stem cells, leading to abnormal embryonic development and abortion. While exposure to A30 during late pregnancy had little or no impact on dams and fetuses. These findings suggest the safety of biomedical applications employing AuNPs during pregnancy is strongly influenced by fetal maturity and gestational age at exposure and provide the clues for AuNPs safe application period in pregnancy. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
150. Respiratory Network Stability and Modulatory Response to Substance P Require Nalcn.
- Author
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Yeh, Szu-Ying, Huang, Wei-Hsiang, Wang, Wei, Ward, Christopher S., Chao, Eugene S., Wu, Zhenyu, Tang, Bin, Tang, Jianrong, Sun, Jenny J., Esther van der Heijden, Meike, Gray, Paul A., Xue, Mingshan, Ray, Russell S., Ren, Dejian, and Zoghbi, Huda Y.
- Subjects
- *
RESPIRATION , *GROWTH associated protein-43 , *BRAIN stem , *NEUROPEPTIDES , *SODIUM channels - Abstract
Summary Respiration is a rhythmic activity as well as one that requires responsiveness to internal and external circumstances; both the rhythm and neuromodulatory responses of breathing are controlled by brainstem neurons in the preBötzinger complex (preBötC) and the retrotrapezoid nucleus (RTN), but the specific ion channels essential to these activities remain to be identified. Because deficiency of sodium leak channel, non-selective ( Nalcn ) causes lethal apnea in humans and mice, we investigated Nalcn function in these neuronal groups. We found that one-third of mice lacking Nalcn in excitatory preBötC neurons died soon after birth; surviving mice developed apneas in adulthood. Interestingly, in both preBötC and RTN neurons, the Nalcn current influences the resting membrane potential, contributes to maintenance of stable network activity, and mediates modulatory responses to the neuropeptide substance P. These findings reveal Nalcn’s specific role in both rhythmic stability and responsiveness to neuropeptides within the respiratory network. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
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