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Nano-layered ternary compounds M n+1 AX n phases combine properties of both ceramics and metals, holding promising prospect for various applications. In this work, the microstructure evolution of coarse Ti 3 AlC 2 particles, as well as the microstructure, physical properties and arc-induced degradation of Ag/Ti 3 AlC 2 electrical contact materials (ECMs) with varying particle sizes of Ti 3 AlC 2 were investigated. The Ti 3 AlC 2 particles milled by vibration were inhomogeneous, whereas those milled through high energy ball milling for 3 h were basically uniformly refined and delaminated to nano-flakes with edge length of ∼100–350 nm without obvious decomposition. With decreasing particle size, the interaction between Ag and Ti 3 AlC 2 was enhanced, thus mitigating the decrease of density and hardness after sintering. Though fine Ti 3 AlC 2 particles led to increased hardness, easier decomposition of finer Ti 3 AlC 2 during both sintering and arc erosion resulted in greater thermal accumulation and accelerated erosion process, thus negatively impacting the arc erosion resistance of Ag/Ti 3 AlC 2 ECMs. [ABSTRACT FROM AUTHOR]

Background: Ultra‐high dose rate (FLASH) radiation has been reported to efficiently suppress tumor growth while sparing normal tissue; however, the mechanism of the differential tissue sparing effect is still not known. Oxygen has long been known to profoundly impact radiobiological responses, and radiolytic oxygen depletion has been considered to be a possible cause or contributor to the FLASH phenomenon. Purpose: This work investigates the impact of tissue pO2 profiles, oxygen depletion per unit dose (g), and the oxygen concentration yielding half‐maximum radiosensitization (the average of its maximum value and one) (k) in tumor and normal tissue. Methods: We developed a model that considers the dependent relationship between oxygen depletion and change of radiosensitivity by FLASH irradiation. The model assumed that FLASH irradiation depletes intracellular oxygen more rapidly than it diffuses into the cell from the extracellular environment. Cell survival was calculated based on the linear quadratic‐linear model and the radiosensitivity related parameters were adjusted in 1 Gy increments of the administered dose. The model reproduced published experimental data that were obtained with different cell lines and oxygen concentrations, and was used to analyze the impact of parameter uncertainties on the radiobiological responses. This study expands the oxygen depletion analysis of FLASH to normal human tissue and tumor based on clinically determined aggregate and individual patient pO2 profiles. Results: The results show that the pO2 profile is the most essential factor that affects biological response and analyses based on the median pO2 rather than the full pO2 profile can be unreliable and misleading. Additionally, the presence of a small fraction of cells on the threshold of radiobiologic hypoxia substantially alters biological response due to FLASH oxygen depletion. We found that an increment in the k value is generally more protective of tumor than normal tissue due to a higher frequency of lower pO2 values in tumors. Variation in the g value affects the dose at which oxygen depletion impacts response, but does not alter the dose‐dependent response trends, if the g value is identical in both tumor and normal tissue. Conclusions: The therapeutic efficacy of FLASH oxygen depletion is likely patient and tissue‐dependent. For breast cancer, FLASH is beneficial in a minority of cases; however, in a subset of well oxygenated tumors, a therapeutic gain may be realized due to induced normal tissue hypoxia. [ABSTRACT FROM AUTHOR]

This paper addresses the image-based visual servoing (IBVS) control problem with an uncalibrated camera, unknown dynamics, and constraints. A novel data-driven uncalibrated IBVS (UIBVS) strategy is proposed, incorporated with the Koopman-based model predictive control (KMPC) algorithm and the adaptive robust Kalman filter (ARKF). First, to alleviate the need for calibration of the camera's intrinsic and extrinsic parameters, the ARKF with an adaptive factor is utilized to estimate the image Jacobian matrix online, thereby eliminating the laborious camera calibration procedures and improving robustness against camera disturbances. Then, a data-driven MPC strategy is proposed, wherein the unknown nonlinear dynamic model is learned using the Koopman operator theory, resulting in a linear Koopman prediction model. Only input–output data are used to construct the prediction model, and hence, the proposed approach is robust against model uncertainties. Furthermore, with a symmetric quadratic cost function, the proposed approach solves the quadratic programming problem online, and visibility constraints as well as joint torque constraints are taken into account. As a result, the proposed KMPC scheme can be implemented in real time, and the UIBVS performance degradation which arises from the control torque constraints can be avoided. Simulations and comparisons for a 2-DOF robotic manipulator demonstrate the feasibility of the proposed approach. Simulation results further validate that the computation time of the proposed approach is comparable to the one of kinematic-based methods. [ABSTRACT FROM AUTHOR]

Introduction: Lung cancer is one of primary cancer type with high incidence and mortality, non-small cell lung cancer (NSCLC) is the most common type of lung cncer. For advanced lung cancer, traditional chemotherapy and targeted therapy become difficult to solve the dilemma of further progress. In recent years, with the clinical application of immunotherapy, the therapeutic strategy of lung cancer has changed dramatically. At present, immunotherapy has shown conspicuous efficacy in NSCLC patients with high expression of programmed death-ligand 1 (PD-L1) and high tumor mutational burden (TMB). The discovery of driver mutations brings delightful hope for targeted cancer therapy. However, it remains controversial whether immunotherapy can be used in NSCLC patients with these specific driver mutations. Method: This article summarized the latest research progresses of immunotherapy in advanced NSCLC. We paid close attention to the relevance of various driver mutations and immunotherapy in NSCLC patients, and summarized the predictive effects of several driver mutations and immunotherapy. Results: The mutations of KRAS, KRAS+TP53, EPHA (especially EPHA5), ZFHX3, ZFHX3+TP53, NOTCH, BRAF and LRP1B+FAT3 have potential to be used as biomarkers to predict the positive effectiveness of immunotherapy. ZFHX3, ZFHX3+TP53, STKII/LKB1+KEAP1+SMARCA4+PBRM1 mutations in LUAD patients get more positive effect in immunotherapy. While the mutations of EGFR, KEAP1, STKII/LKB1+KRAS, EML4-ALK, MET exon 14 skipping mutation, PBRM1, STKII/LKB1+KEAP1+SMARCA4+PBRM1, ERBB2, PIK3CA and RET often indicate poor benefit from immunotherapy. Conclusion: Many gene mutations have been shown to be associated with immunotherapy efficacy. Gene mutations should be combined with PD-L1, TMB, etc. to predict the effect of immunotherapy. [ABSTRACT FROM AUTHOR]

In the present study, a fluid-filled RF MEMS (Radio Frequency Micro-Electro-Mechanical Systems) switch is proposed and designed. In the analysis of the operating principle of the proposed switch, air, water, glycerol and silicone oil were adopted as filling dielectric to simulate and research the influence of the insulating liquid on the drive voltage, impact velocity, response time, and switching capacity of the RF MEMS switch. The results show that by filling the switch with insulating liquid, the driving voltage can be effectively reduced, while the impact velocity of the upper plate to the lower plate is also reduced. The high dielectric constant of the filling medium leads to a lower switching capacitance ratio, which affects the performance of the switch to some extent. By comparing the threshold voltage, impact velocity, capacitance ratio, and insertion loss of the switch filled with different media with the filling media of air, water, glycerol, and silicone oil, silicone oil was finally selected as the liquid filling medium for the switch. The results show that the threshold voltage is 26.55 V after filling with silicone oil, which is 43% lower under the same air-encapsulated switching conditions. When the trigger voltage is 30.02 V, the response time is 10.12 μs and the impact speed is only 0.35 m/s. The frequency 0–20 GHz switch works well, and the insertion loss is 0.84 dB. To a certain extent, it provides a reference value for the fabrication of RF MEMS switches. [ABSTRACT FROM AUTHOR]

Broken rotor bar diagnosis in squirrel cage induction motors is a matter of increasing concern nowadays. The classical motor current signature analysis (MCSA), based on the Fourier analysis of the steady-state current, does not achieve good results when the motor runs in the start-up transient. In this paper, a novel approach is presented for detecting broken rotor bars (BRBs) in squirrel cage induction motors started at a constant frequency. It is shown that, in the case of motors with BRBs, the theoretical evolution of the instantaneous frequency fi of the characteristic harmonic in squared Park vector modulus signal versus slip s is always manifests itself by a straight line with slope k equal to 100, which is physically justified using theoretical analysis. In the proposed approach, the discrete wavelet transform (DWT) is used to extract characteristic harmonics from the squared park vector modulus signal. Then, the instantaneous frequency (IF) of the resultant characteristic harmonics is calculated via the Hilbert transform (HT). The occurrence of failure is determined according to the correlation between the symbolized experimental s–fi and its theoretical evolution in the s–fi plane, and the fault severity is judged according to the energy of the fault characteristic harmonic signal. Experimental results of a 3 kW motor verify the validity of the theoretical analysis and the proposed diagnosis approach during the start-up transient. [ABSTRACT FROM AUTHOR]

This paper numerically investigates the effects of rigid coupling and the vibration degrees of freedom on the vortex-induced vibrations (VIV) of two tandem circular cylinders for a spacing ratio L/D = 4 at a Reynolds number of 150. Two (translational vibration) and three (translational and rotational vibration) degrees of freedom (RC-2DOF and RC-3DOF, respectively) cases are considered and compared with the case of two freely vibrating cylinders (FC). The dynamic response characteristics, flow structures, and vortex dynamics are analyzed. The results show that the rigid coupling has a significant effect on VIV. Compared with FC, the maximum transverse amplitude of the downstream cylinder decreases by 30% for RC-2DOF and approximately 15% for RC-3DOF. The lock-in region narrows by 40% for RC-2DOF, while it widens by 80% for RC-3DOF. Reattachment and co-shedding regions are observed for FC and RC-3DOF, whereas only the co-shedding region exists for RC-2DOF. We further explore flow forces and fluid–structure-interaction mechanisms in the lock-in region for RC-3DOF. The rotation of the twin-cylinder system triggers some unique vibration characteristics, such as two transverse amplitude peaks of the upstream cylinder and a prominent streamwise amplitude at Vr = 7–9. The vortex-to-vortex and vortex-to-cylinder interactions are complicated and changeable with reduced velocity for RC-3DOF. [ABSTRACT FROM AUTHOR]

Influence maximization aims at the identification of a small group of individuals that may result in the most wide information transmission in social networks. Although greedy-based algorithms can yield reliable solutions, the computational cost is extreme expensive, especially in large-scale networks. Additionally, centrality-based heuristics tend to suffer from the problem of low accuracy. To solve the influence maximization problem in an efficient way, a learning-automata-driven discrete butterfly optimization algorithm (LA-DBOA) mapped into the network topology is proposed in this paper. According to the LA-DBOA framework, a novel encoding mechanism and discrete evolution rules adapted to network topology are presented. By exploiting the asymmetry of social connections, a modified learning automata is adopted to guide the butterfly population toward promising areas. Based on the topological features of the discrete networks, a new local search strategy is conceived to enhance the search performance of the butterflies. Extensive experiments are conducted on six real networks under the independent cascade model; the results demonstrate that the proposed algorithm achieves comparable influence spread to that of CELF and outperforms other classical methods, which proves that the meta-heuristics based on swarm intelligence are effective in solving the influence maximization problem. [ABSTRACT FROM AUTHOR]

The logic gate is the basic unit of a digital circuit structure. The operation, memory, I/O, and other reading and writing functions of computer systems require logic circuits. Logic gates based on resistive memory can make existing integrated circuits denser, smaller, faster, and use fewer devices. In this paper, Al/polymethyl methacrylate (PMMA)/egg albumen (EA):Au nanoparticles/PMMA/Al multilayer biological resistive random access memory was prepared based on the natural biological material—egg albumen (EA). The device has bipolar switching behavior, a higher switching current ratio, a lower threshold voltage, and better stability. A circuit based on auxiliary logic is constructed using this device, and the logic functions of AND, OR, NOT, NAND, and NOR are realized. This device provides an effective potential solution for implementing high-performance electronic devices and large-scale integrated circuits. [ABSTRACT FROM AUTHOR]

Background: Little is known about patients' intention for participation in end-of-life decisions (EOLD) in three coastal provinces in southern China. This study aimed to explore the willingness of patients with cancer pain to participate in EOLD and potential influencing factors. Methods: A multi-center cross-sectional study was performed in three coastal provinces in southern China. Two hundred and thirty patients with cancer pain were recruited and consented to fill out the questionnaires. The patients' willingness to participate in EOLD, demographic and disease-related data was surveyed. Results: In total, 223 patients completed and returned the survey (response rate = 96.95%). One hundred four cases (46.64%) were willing to participate in EOLD. 119 (54.36%) cases not willing to participate in EOLD, respectively. Multivariate logistic regression analysis shows that educational level (OR: 0.683, 95% CI: 0.482–0.966), history of alcoholism (OR: 8.353, 95%CI: 2.535–27.525), Eastern Cooperative Oncology Group (ECOG) score (OR: 0.645, 95% CI: 0.450–0.925) and experience of explosive pain (OR: 6.367, 95% CI: 3.103–13.062) and clinical rescue (OR: 3.844, 95% CI: 1.722–8.577) had significant effects on EOLD intention (P < 0.05). Finally, a predictive model combined above five factors was established, which showed a good discrimination (area under receiver operating characteristic curve: 0.849, 95% CI: 0.796–0.899, P < 0.001) and calibration (Hosmer-Lemeshow Test: Chi-square = 10.103, P = 0.258) for which patients more willing to participate in EOLD. Conclusions: The willingness of patients with cancer pain to participate in EOLD is at a modest level in three coastal provinces in southern China. Patients with lower educational level, history of alcoholism, better health status and experience of explosive pain and clinical rescue may be more prone to participate in EOLD. [ABSTRACT FROM AUTHOR]

Immune system dysregulation is associated with tumor incidence and growth. Here, we established an RNA-based individualized immune signature associated with prognosis for nonsmall cell lung cancer (NSCLC) to guide adjuvant therapy. We downloaded publicly accessible data on RNA expression and clinical characteristics of NSCLC from the Cancer Genome Atlas (TCGA). From immune-related genes (IRGs) retrieved from the immunology database and analysis portal (ImmPort) database, we then screened differentially expressed immune-related genes (DEIRGs). Using overall survival (OS) as a clinical endpoint, we identified 26 prognostic DEIRGs via univariate and multivariate Cox regression analysis, and then developed a risk model based on these 26 IRGs with an area under the curve (AUC) of 0.701, and its predictive ability independent from other clinical factors. We also downloaded tumor immune infiltrate data and analyzed the correlations between lymphocytic infiltration with our risk scores, but found no significant association. Furthermore, we retrieved 86 differentially expressed transcription factors (TFs) to assess their regulatory relationships with the 26 prognostic DEIRGs. In summary, we developed a robust risk model to predict survival in patients with NSCLC, based on the expression of 26 IRGs. It provides novel predictive and therapeutic molecular targets. [ABSTRACT FROM AUTHOR]

The tracking of satellite signals with the passive linearly polarized embedded global navigation satellite system (GNSS) antenna of smartphones in dynamic scenarios is susceptible to the changing multipath and obstructions in urban environments, which lead to a significant decrease in the availability and reliability of GNSS solutions. Accordingly, based on the characteristics of smartphone GNSS and inertial measurement unit (IMU) sensors data in GNSS-degraded environments, we established an IMU-aided uncombined precise point positioning (PPP) mathematical model that is suitable for smartphones. To enhance the reliability of initial alignment in dynamic mode, the step function variances depending on carrier-to-noise density ratio were established with the variances of GNSS measurements, and the inertial navigation system (INS) parameters were initialized while both the velocity of smartphones and the position dilution of precision (PDOP) reached corresponding thresholds. Considering the measurement noise and observations gaps of smartphones, the robust Kalman filter (RKF) with equivalent variance matrix was used for parameter estimation to improve the convergence efficiency of the coupled PPP/INS model. Experimental results indicated that the proposed PPP/INS method can effectively improve the positioning performance of smartphones in GNSS-degraded environments. Compared with the conventional smartphone PPP scheme, the PPP/INS horizontal errors in the eastern and western areas of the long trajectory experiment decreased by 49.37% and 48.29%, respectively. Meanwhile, the trajectory deviation of smartphones can remain stable in the tunnel where GNSS signals are blocked. [ABSTRACT FROM AUTHOR]

With the development of deep learning, considerable progress has been made in image restoration. Notably, many state-of-the-art single image super-resolution (SR) methods have been proposed. However, most of them contain many parameters, which leads to a significant amount of calculation consumption in the inference phase. To make current SR networks more lightweight and resource-friendly, we present a convolution neural network with the proposed selective channel processing strategy (SCPN). Specifically, the selective channel processing module (SCPM) is first designed to dynamically learn the significance of each channel in the feature map using a channel selection matrix in the training phase. Correspondingly, in the inference phase, only the essential channels indicated by the channel selection matrixes need to be further processed. By doing so, we can significantly reduce the parameters and the calculation consumption. Moreover, the differential channel attention (DCA) block is proposed, which takes into consideration the data distribution of the channels in feature maps to restore more high-frequency information. Extensive experiments are performed on the natural image super-resolution benchmarks (i.e., Set5, Set14, B100, Urban100, Manga109) and remote-sensing benchmarks (i.e., UCTest and RESISCTest), and our method achieves superior results to other state-of-the-art methods. Furthermore, our method keeps a slim size with fewer than 1 M parameters, which proves the superiority of our method. Owing to the proposed SCPM and DCA, our SCPN model achieves a better trade-off between calculation cost and performance in both general and remote-sensing SR applications, and our proposed method can be extended to other computer vision tasks for further research. [ABSTRACT FROM AUTHOR]

As the most promising future generation green ship, hybrid energy ship power systems (HESPS) have gradually attracted attention. However, the integration of new energy including wind energy and solar energy, raises key challenges in designing a suit optimal dispatch for HESPS under different navigation conditions. Based on this, an optimal dispatch strategy using the improved Non-dominated Sorting Genetic (NSGA-II) algorithm is proposed. Firstly, an integrated HESPS model consisting of diesel power generation system, energy storage system (ESS), wind power generation system (WPGS) and photovoltaic power generation system is established. Based on this, a multi-objective optimization strategy is proposed to reduce the cost and greenhouse gas emissions. Through the design of crossover operator and mutation operator, an improved NSGA-II is developed to find optimal solutions. Finally, three cases are presented to test the performance of proposed optimal dispatch strategy. Compared with traditional NSGA-II and multi-objective particle swarm optimization (MOPSO), the indicator of Hypervolume, Proportion of independent solutions, Generational Distance (GD) and Inverted Generational Distance can be improved at least 0.39%, 0.18%, 1.85% and 15.87%. At the same time, the corresponding cost and energy efficiency operational index (EEOI) of HESPS can be reduced by 13.17% and 17.53%. • Hybrid energy ship model including DGs, ESS, WPGS, PV etc., is explored. • A novel optimal dispatch strategy using the improved NSGA-II is proposed. • Compared with existing methods, optimization performance can be improved. • EEOI and reduce greenhouse gas emissions can be reduced by 13.17% and 17.53%. [ABSTRACT FROM AUTHOR]

The most challenge of influence maximization (IM) is to locate a finite set of influencers while maximizing the influence dissemination in a social network. Due to the increasingly widespread and complex application scenarios of IM problem, how to solve the problem effectively remains as a prominent research hotspot. However, most of the existing IM algorithms tend to prioritize either lightweight computational time or solution accuracy, which are hard to be acquired simultaneously. Therefore, considering the trade-off between efficiency and effectiveness, a novel discrete hybrid optimizer by integrating butterfly optimization algorithm (BOA) with differential evolution (DE), named DBOA-DE, is proposed in this paper. An adaptive probability is designed to guide the two operations in the hybrid optimizer, where BOA shows excellent exploratory characteristics by simulating the behavior of butterfly swarms, while DE performs local exploitation through mutation and crossover procedures. Furthermore, in expectation of enhancing the solution accuracy, an improved local search policy is conceived to avoid DBOA-DE from falling into local optimum. Extensive experiments on six real-world social networks show that DBOA-DE outperforms baseline algorithms on influence propagation while maintaining acceptable efficiency, which validate the promising effectiveness and efficiency of the proposed algorithm for IM problems. [ABSTRACT FROM AUTHOR]

Missing values in air quality datasets bring trouble to exploration and decision making about the environment. Few imputation methods aim at time series air quality data so that they fail to handle the timeliness of the data. Moreover, most imputation methods prefer low-missing-rate datasets to relatively high-missing-rate datasets. This paper proposes a novel missing data imputation method, called FTLRI, for time series air quality data based on the traditional logistic regression and a presented "first Five & last Three" model, which can explain relationships between disparate attributes and extract data that are extremely relevant, both in terms of time and attributes, to the missing data, respectively. To investigate the performance of FTLRI, it is benchmarked with five classical baselines and a new dynamic imputation method using a neural network with average hourly concentration data of pollutants from three disparate stations in Lanzhou in 2019 under different missing rates. The results show that FTLRI has a significant advantage over the compared imputation approaches, both in the particular short-term and long-term time series air quality data. Furthermore, FTLRI has good performance on datasets with a relatively high missing rate, since it only selects the data extremely related to the missing values instead of relying on all the other data like other methods. [ABSTRACT FROM AUTHOR]

Background: Ultrahigh dose‐rate irradiation (FLASH‐IR) was reported to be efficient in tumor control while reducing normal tissue radiotoxicity. However, the mechanism of such phenomenon is still unclear. Besides, the FLASH experiments using high energy X‐ray, the most common modality in clinical radiotherapy, are rarely reported. This study aims to investigate the radiobiological response using 6 MV X‐ray FLASH‐IR or conventional dose‐rate IR (CONV‐IR). Methods: The superconducting linac of Chengdu THz Free Electron Laser (CTFEL) facility was used for FLASH‐IR, a diamond radiation detector and a CeBr3 scintillation detector were used to monitor the time structure and dose rate of FLASH pulses. BALB/c nude mice received whole abdominal 6 MV X‐ray FLASH‐IR or CONV‐IR, the prescribed dose was 15 Gy or 10 Gy and the delivered absolute dose was monitored with EBT3 films. The mice were either euthanized 24 h post‐IR to evaluate acute tissue responses or followed up for 6 weeks to observe late‐stage responses and survival probability. Complete blood count, histological analyses, and measurement of cytokine expression and redox status were performed. Results: The mean dose rate of >150 Gy/s and instantaneous dose rate of >5.5 × 105 Gy/s was reached in FLASH‐IR at the center of mice body. After 6 weeks' follow‐up of mice that received 15 Gy IR, the FLASH group showed faster body weight recovery and higher survival probability than the CONV group. Histological analysis showed that FLASH‐IR induced less acute intestinal damage than CONV‐IR. Complete blood count and cytokine concentration measurement found that the inflammatory blood cell counts and pro‐inflammatory cytokine concentrations were elevated at the acute stage after both FLASH‐IR and CONV‐IR. However, FLASH irradiated mice had significantly fewer inflammatory blood cells and diminished pro‐inflammatory cytokine at the late stage. Moreover, higher reactive oxygen species (ROS) signal intensities but significantly reduced lipid peroxidation were found in the FLASH group than in the CONV group in the acute stage. Conclusions: The radioprotective effect of 6 MV X‐ray FLASH‐IR was observed. The differences in inflammatory responses and redox status between the two groups may be the factors responsible for reduced radiotoxicities following FLASH‐IR. Further studies are required to thoroughly evaluate the impact of ROS on FLASH effect. [ABSTRACT FROM AUTHOR]

In the present study, 27 bacterial strains were isolated from environmental samples and screened for higher lignocellulose-degrading efficiency. The best degrader was combined in pairs with 14 strains with high β-glucosidase activity to formulate a consortium. Microbial consortium 625 showed high lignocellulose degradation efficiency. ZJW-6 with low β-glucosidase activity and the best lignocellulose decomposer was identified as a member of Cellulomonas. Consortium 625 composed of ZJW-6 and DA-25, an Acinetobacter, showed the highest degradation rate (57.62%) under optimized conditions. The DA-25 filtrate promoted ZJW-6 growth, upregulating the activity of key lignocellulose-degrading enzymes, including β-glucosidase, endoglucanase, xylanase, laccase, and lignin peroxidase. ZJW-6 and DA-25 worked in a subordination manner when co-cultivated. ZJW-6 acted as the major decomposer whose growth and enzymatic activities were promoted by DA-25. This study proposes a novel microbial consortium with improved lignocellulose degradation efficiency and reduce the C:N ratio of lignocellulose materials, which can enhance bioenergy production. [ABSTRACT FROM AUTHOR]

Food safety and food freshness issues have become important concerns for consumers and hydrogels with high antibacterial efficiency, low toxicity and pH−sensitive colorimetric intelligence are one of candidates to meet the requirement of food package and food spoilage monitoring. Nevertheless, hydrogels prepared only by assembling the ingredients with non−covalent interactions through time−consuming molding process usually encounter drawbacks such as relatively poor mechanical properties, stability and thermal stability, which always restrict their further applications. To overwhelm these shortcomings, UV−curable choline chloride (ChCl) and bromophenol red (BR) covalent functionalized antibacterial and pH−sensitive cross−linked hydrogels (UV−hydrogels) were developed in this paper. The UV−hydrogels possessed good thermal stability because the initiated thermal decomposition temperature (T d5) is in the range of 135.8–184.7 °C. The DMA analysis revealed that the UV−hydrogels are with good mechanical properties because the elongation at break is in the range of 117–525% and the tensile strength is in the range of 0.8–2.7 MPa. The UV−hydrogels with BR groups exhibited naked eye visible color variation from yellow to dark blue-green with the variation of the pH values from 2 to 14. The antibacterial efficiency of the UV−hydrogels against S. aureus , E. coli and M. albican increased with the increment of covalent−grafted ChCl amount. Cytotoxicity assay demonstrated that the UV−hydrogels are low toxicity against L929 cells. The experiment of monitoring freshness of beef denoted the UV−hydrogels have potential application in animal–derived high protein food packaging and freshness monitoring. [Display omitted] • Good flexibility with elongation at break of 117–525% and tensile strength of 0.8–2.7 MPa. • pH−Sensitive colorimetric intelligence with the variation of the pH values from 2 to 14. • Good antibacterial performance against S. aureus , E. coli and M. albican. • Potential application in animal–derived high protein food packaging and spoilage monitoring. [ABSTRACT FROM AUTHOR]

Deep learning techniques and deep networks have recently been extensively studied and widely applied to single image super‐resolution (SR). Among them, channel attention has garnered the most focus owing to its significant boost in the presentational power of a convolutional neural network. However, the original channel attention neglects the critical importance of the positional information, thus imposing performance limitations. Here, a novel perspective, namely, a coordinate attention mechanism, is explored to alleviate the aforementioned problem, and accordingly result in an enhanced SR performance. Specifically, a deep residual coordinate attention SR network (COSR) is proposed, which mainly incorporates the presented coordinate attention blocks into a deep nested residual structure. The coordinate attention captures the positional information by computing the average value vector from the two spatial directions, thus aggregating the features in different coordinates. The nested residual blocks pass low‐frequency information from the top to the end through the skip connection lines, allowing convolution filters to concentrate more on high‐frequency textures and edges, thereby reducing the difficulty of reconstruction. Extensive experiments demonstrate that our proposed COSR achieves a better performance and exceeds many state‐of‐the‐art SR methods in terms of both quantitative metrics and visual quality. [ABSTRACT FROM AUTHOR]

Rocuronium is widely utilized in clinical general anaesthesia, and individual differences in pharmacology and clearance have been observed. Two hundred thirty‐six Chinese patients undergoing selective thyroid/breast mass resection were studied. Total intravenous anaesthesia was induced with a single dose of propofol (2 mg·kg−1), sufentanil (0.5 μg·kg−1), and rocuronium (0.6 mg·kg−1) and maintained with propofol (3–5 mg·kg−1·h−1) and remifentanil (0.2–0.4 μg·kg−1·min−1). Intubation conditions and a train‐of‐four index of patients were utilized to assess the effects and duration of rocuronium. The data from 228 patients were analysed and reported. Genotypes NR1I2 rs2472677 C > T, NR1I2 rs6785049 G > A, SLCO1B1 rs4363657 T > C, SLCO1A2 rs4762699 T > C, and UGT1A1 rs4148323 G > A contributed to individual variation in rocuronium. Of the clinical variables tested, age, BMI, total dose of propofol, NR1I2 rs2472677, and SLCO1A2 rs4762699 correlated significantly (P < 0.05 for all) with the clinical duration or total clinical action time of rocuronium in a multiple linear regression model. No significant interactions were observed in intubation conditions. Genetic variations in NR1I2 rs2472677, NR1I2 rs6785049, SLCO1B1 rs4363657, SLCO1A2 rs4762699, and UGT1A1 rs4148323 were related to extensive interindividual variability in the clinical duration and total clinical action time of rocuronium. [ABSTRACT FROM AUTHOR]

A multistate data memory device can store more than one bit in each cell. Such devices have broad application prospects because they provide a simple and low-cost way to improve memory capacity. As a biomaterial, silkworm hemolymph (SH) has the advantages of being easily accessible, biodegradable and biocompatible. In this study, performance-tunable multistate data storage devices with an indium tin oxide (ITO)/graphene oxide (GO)/SH/GO/Al structure were fabricated with SH and GO as dielectric layers. The results show that the proposed device structure has stable nonvolatile and bipolar switching characteristics. The conductivity and ON/OFF current ratio (1–103) of such a device can be adjusted by modifying the GO concentration. With appropriate control of the compliance current (I CC), the device can be switched to six different resistance states, enabling multistate data storage capabilities and allowing high-density data storage to be realized. These devices have a long retention time (104 s) and extended endurance. Their switching behavior is attributed to the formation and fracture of oxygen vacancy conductive filaments. This research introduces a new approach to the development of biocompatible high-density memory devices. [ABSTRACT FROM AUTHOR]

Purpose. Recent studies suggest ultra-high dose rate (FLASH) irradiation can spare normal tissues from radiotoxicity, while efficiently controlling the tumor, and this is known as the 'FLASH effect'. This study performed theoretical analyses about the impact of radiolytic oxygen depletion (ROD) on the cellular responses after FLASH irradiation. Methods. Monte Carlo simulation was used to model the ROD process, determine the DNA damage, and calculate the amount of oxygen depleted (LROD) during FLASH exposure. A mathematical model was applied to analyze oxygen tension (pO2) distribution in human tissues and the recovery of pO2 after FLASH irradiation. DNA damage and cell survival fractions (SFs) after FLASH irradiation were calculated. The impact of initial cellular pO2, FLASH pulse number, pulse interval, and radiation quality of the source particles on ROD and subsequent cellular responses were systematically evaluated. Results. The simulated electron LROD range was 0.38–0.43 μM Gy−1 when pO2 ranged from 7.5 to 160 mmHg. The calculated DNA damage and SFs show that the radioprotective effect is only evident in cells with a low pO2. Different irradiation setups alter the cellular responses by modifying the pO2. Single pulse delivery or multi-pulse delivery with pulse intervals shorter than 10–50 ms resulted in fewer DNA damages and higher SFs. Source particles with a low linear energy transfer (LET) have a higher capacity to deplete oxygen, and thus, lead to a more conspicuous radioprotective effect. Conclusions. A systematic analysis of the cellular response following FLASH irradiation was performed to provided suggestions for future FLASH applications. The FLASH radioprotective effect due to ROD may only be observed in cells with a low pO2. Single pulse delivery or multi-pulse delivery with short pulse intervals are suggested for FLASH irradiation to avoid oxygen tension recovery during pulse intervals. Source particles with low LET are preferred for their conspicuous radioprotective effects. [ABSTRACT FROM AUTHOR]

Purpose: Research regarding cellular responses at different oxygen concentrations (OCs) is of immense interest within the field of radiobiology. Therefore, this study aimed to develop a mechanistic model to analyze cellular responses at different OCs. Methods: A DNA damage model (the different cell oxygen level DNA damage [DICOLDD] model) that examines the oxygen effect was developed based on the oxygen fixation hypothesis, which states that dissolved oxygen can modify the reaction kinetics of DNA‐derived radicals generated by ionizing radiation. The generation of DNA‐derived radicals was simulated using the Monte Carlo method. The decay of DNA‐derived radicals due to the competing processes of chemical repair, oxygen fixation, and intrinsic damaging was described using differential equations. The DICOLDD model was fitted to the previous experimental data obtained under different irradiation configurations and validated by calculating the yields of DNA double‐strand breaks (DSBs) after exposure to 137Cs as well as cell survival fractions (SFs) using a mechanistic model of cellular survival. Moreover, we used the DICOLDD model to calculate DNA DSB damage yields after irradiation with 0.5–50 MeV protons. Results: Generally, DSB yields calculated after exposure to 137Cs at different OCs correspond to statistical uncertainties of previous experimental results. Calculated SFs of CHO and V79 cells exposed to photons, protons, and alpha particles at different OCs generally concur with those obtained in previous studies. Our results demonstrated that the variation in DSB yields was less than 10% when the cellular OC decreased from 21% to 5%. Additionally, DSB yields changed drastically when OC dropped below 1%. Conclusions: We developed a DNA damage model to evaluate the oxygen effect and provide evidence that a reaction‐kinetic model of DNA‐derived radicals induced by ionizing radiation suffices to explain the observed oxygen effects. Therefore, the DICOLDD model is a powerful tool for the analysis of cellular responses at different OCs after exposure to different types of radiation. [ABSTRACT FROM AUTHOR]

This article presents an integrated magnetic buck–boost converter (IMBBC) with a positive output voltage. The input inductor, two power transfer inductors, and an auxiliary inductor in the ripple cancellation network of this converter are integrated in one magnetic core, and an additional capacitor is included for output current ripple cancellation. The IMBBC inherently operates in the continuous conduction mode and exhibits a nonpulsating input current and a very low ripple output current, thereby not only decreasing the current stress on both the input and output capacitors but also reducing the output voltage ripple. Because the input of the IMBBC is connected to the output during the switch-on period (similar to the operation of buck converters), the proposed IMBBC overcomes the right-half-plane zero problem in the buck or boost mode, thus achieving a higher dynamic performance. The use of the magnetic integration technique not only helped realize the aforementioned performance, but can also help reduce the weight and volume of dc–dc converters. Finally, the feasibility and effectiveness of the proposed topology and design approaches are experimentally verified. [ABSTRACT FROM AUTHOR]

The natural mineral-based CoSbS compound has been identified as a potential candidate material for thermoelectric power generation. In this report, the solid solutions of CoSb 1−x S 1−x Se 2x (x ≤ 0.2) were constructed, and their electrical and thermal properties were studied at the temperatures ranging from 323 to 823 K. The results show that the dual doping of Se on Sb and S sites not only tunes the carrier concentration but also modifies the electronic structure, thereby optimizing the power factor of CoSbS effectively. Meanwhile, both the mass and the strain field fluctuation caused by the substitution of Se for both Sb and S strongly suppress the thermal conductivity of CoSbS, and finally make an enhanced zT ∼0.3 for CoSb 0.8 S 0.8 Se 0.4 at 823 K. In particular, the maximum averaged zT from 323 to 823 K in this study reaches ∼0.2, far exceeding the results of Se doping at single Sb or S site in CoSbS. These results indicate that dual doping at Sb and S sites via Se is an effective approach to make better thermoelectric performance for CoSbS. • Thermoelectric compound CoSbS with dual defects of Se Sb and Se S was constructed. • The carrier concentration and electronic structure of CoSbS were modified effectively by introducing of Se Sb and Se S defects. • An enhanced zT avg was obtained for CoSbS with Se Sb and Se S defects. [ABSTRACT FROM AUTHOR]

For structural geology and geophysical exploration, it is of particular importance to get accurate images of salt domes, especially the subsalt weakly illuminated regions and the steep salt flanks. One-way wave propagators are widely used for imaging because of the high computational efficiency, low memory utilization and capability to handle models with large velocity variations. However, traditional one-way propagators cannot simulate waves propagating at large angles within 90°, making it difficult to image steep structures. To overcome the limitation of imaging steeply dipping reflectors and weakly illuminated regions, we propose a sparsity-promoting wide-angle least-squares one-way migration method (SPWA-LSM). For details, the subsurface space is divided into several fan-shaped sub-domains, and the axis of each sub-domain is used as the local wave propagation direction. Then in each of the domains, we extrapolate the wavefields in different directions by rotating the propagation operator. Finally, we use the weight function to combine the extrapolated wavefields according to the propagation angle, thus obtaining the wide-angle propagation operator. The wide-angle propagation operator is extended to the least-squares migration framework (LSM), and then the transform domain sparsity constraint is added to the wide-angle least-squares migration (WA-LSM) to further improve imaging quality. Using the SEG/EAGE salt model and the BP2.5d model, we demonstrate the validity of the method in imaging steep subsalt structures. [ABSTRACT FROM AUTHOR]

The simulation technology of wind and solar power output can provide data support for the planning of new energy stations and the optimization and scheduling of power systems. In order to solve the problem that the existing output models can not accurately describe the dynamic spatio-temporal dependence between wind and solar output, a dynamic spatiotemporal correlation model of wind and solar output based on Markov stochastic process and Copula function theory is proposed. Firstly, wind power and photovoltaic output are regarded as a stochastic process, and the time autocorrelation models of wind power and photovoltaic output are constructed based on a one-dimensional Markov chain and hybrid Copula function. Next, two one-dimensional Markov chains were coupled to form a two-dimensional Markov chain, and a spatial correlation model between wind and solar output was constructed using the dynamic SJC Copula function. Take the measured data of adjacent wind farms and photovoltaic power stations in Hami, Xinjiang as an example for simulation. The simulation results show that the proposed model can effectively reflect the spatio-temporal correlation of the original data and reflect the dynamic changes in the correlation between wind and solar energy. • There is a complex correlation between output of adjacent wind and solar power plants. • The dynamic spatio-temporal correlation between wind and solar power can be modelled. • Coupling two one-dimensional Markov chains into a two-dimensional Markov chain. • Using the dynamic SJC Copula and mixed Copula function. [ABSTRACT FROM AUTHOR]

The halogen bonding and π-π stacking interactions between pyrazine (C4H4N2) and fluoro substituted iodobenzene C6H5-nFnI (n = 0, 1, 2, 3, 4, and 5) have been discussed at the M062x-D3/aug-cc-pVTZ level. The calculated interaction energy shows that the halogen bonding interactions are weaker than the corresponding π-π stacking interactions in C6H5-nFnI (n = 0, 1, and 2)-C4H4N2 complexes, while the halogen bonding interactions are stronger than the corresponding π-π stacking interactions in C6H5-nFnI (n = 3, 4, and 5)-C4H4N2 complexes. According to SAPT analysis, it is reveals that the electrostatic energy are the primary source of the attraction for the halogen bonding interactions while the π-π stacking interactions are dominantly dispersion energy. When the halogen bond and π-π stacking interaction coexist, we find out that the formation of π-π stacking will lead to stronger halogen bond interaction and the converse is also true. [ABSTRACT FROM AUTHOR]

Sequential switching shunt regulators (S3Rs) are widely used in the satellites owing to their simple structure and high reliability. The high-power communication satellites require a power supply with a high bus voltage and large solar array section current. However, a large solar array capacitance and new time-division multiple access operations complicate the design of a lightweight and cost-effective power supply by increasing the difficulty in dissipation and thermal control. On the basis of passive current limitation, in this article, we propose a novel shunt regulator with only one output diode and a protection strategy to achieve high efficiency, appropriate shunt current limitation, and low turn-off delay. In addition, to reduce the dissipation of an S3R cell when feeding the solar array current to the main bus and to satisfy the single point failure-free requirement, an innovative self-retriggerable diode short-circuit fault detector circuit is proposed, which includes a protection switch for a safe thermal or electrical operation. Finally, simulation and experimental results are presented to validate the proposed shunt regulator and the corresponding control method or protection strategy. [ABSTRACT FROM AUTHOR]

In this work, undoped semiconductors, germanium (Ge) and germanium tin (GeSn), were grown on ferrimagnetic insulator yttrium iron garnet (YIG) thin films using ultra-high vacuum molecular beam epitaxy. The crystallinity of the structure was determined from x-ray diffraction and high-resolution transmission electron microscopy combined with energy dispersive x-ray spectroscopy. Both spin pumping and inverse spin Hall effects (ISHEs) of YIG/Ge and YIG/GeSn heterojunctions have been investigated with the help of broadband ferromagnetic resonance (FMR). We observe that the spin mixing conductances of YIG/Ge (60 nm) and YIG/GeSn (60 nm) are 5.4 × 1018 m−2 and 7.2 × 1018 m−2, respectively, responsible for giant spin current injection. Furthermore, it is found that spin pumping injects giant spin current from ferrimagnetic YIG into the Ge semiconductor. The infrared laser modulated ISHE was examined using heavy metal platinum as a spin current collector. Also, it has been noted that the variation in the power of laser irradiation significantly changed the ISHE voltage of YIG/Ge/Pt spin junctions, saturated magnetization, FMR linewidth, and Gilbert damping parameter of YIG, which could be attributed to the laser-induced thermal effect. The outcomes from this study are promising for the development of Ge-based spintronic and magnonic devices. [ABSTRACT FROM AUTHOR]

In this paper, p-type thermoelectric material Te–Se solid solutions have been successfully prepared by the high-pressure technique. The thermal conductivity of Te was depressed sharply by Se alloying. An extremely low thermal conductivity ∼0.27 W m−1 K−1 was obtained for Te alloyed with 15 mol% Se, which near the theoretical minimum, κ min. The bipolar diffusion effect of Te was suppressed by Se alloying due to the increased band gap, which lead to enhanced Seebeck coefficient and depressed bipolar diffusion thermal conductivity under high temperature. The maximum figure of merit, ZT of 0.37 at 480 K was obtained for Te alloyed with 5 mol% Se, which is about twice higher than that of pristine Te. • Thermoelectric Te–Se solid solutions were facile and fast prepared by one-step high-pressure technique. • The thermal conductivity of Te was depressed sharply and its Seebeck was improved at high temperatures by Se alloying. • An extremely low thermal conductivity ∼0.27 W m−1 K−1 was obtained for Te alloyed with 15 mol%. [ABSTRACT FROM AUTHOR]

The influence maximization problem that has caused great attention in social network analysis aims at selecting a small set of influential spreaders so that the information cascade triggered by the seed set is maximized. The majority of the existing works mainly focus on developing single-stage seeding strategies that would ignite all the seeds before the influence spread. However, it cannot depict the scenarios of the practical, where ones would like to make further decisions based on observed activation. In this paper, we investigate the policies for the intractable sequential influence maximization problem. A Q-learning-driven discrete differential evolution algorithm based on the reinforcement Q-learning model, which is treated as a parameter controller to adaptively adjust the parameters during the evolution of the algorithm, is proposed. The policy distributes the seeding actions over the spreading process by estimating the latest node status of the network dynamically. Extensive simulations are conducted on six social networks of the practical, and the findings demonstrate the superiority and effectiveness of the hybrid meta-heuristic algorithm compared with the state-of-the-art methods. [ABSTRACT FROM AUTHOR]

[Display omitted] • The 2D/2D Janus BiTeCl/GeSe vdW heterostructure (HS) exhibits a direct Z-scheme photocatalytic mechanism. • The HS shows great photocatalytic performance for overall water splitting and is robust enough to be nearly independent of either biaxial or uniaxial strain. • The HS can achieve spontaneous water splitting with the solar-to-hydrogen efficiency up to 19.27 %. Two-dimensional (2D) S-scheme van der Waals (vdW) heterostructures (HSs) have aroused much interest as advanced photocatalysts due to their strong redox ability and light utilization. In this work, we have proposed a 2D/2D vdW HS composed of Janus BiTeCl monolayer (ML) and GeSe ML, and systematically investigated its photocatalytic performance using first-principles calculations. Our results show that the HS exhibits an appropriate electronic band in which the existence of intrinsic built-in electric field from GeSe ML to BiTeCl ML enhances the separation of photo-induced electron-hole pairs and certifies a S-scheme mechanism in the HS. Furthermore, the optical and electronic properties of the HS are nearly independent of either biaxial or uniaxial strain, showing robustness of the HS applied in an ever-changing environment. Notably, the HS can achieve spontaneously solar-driven water splitting and exhibits an enhanced solar-to-hydrogen (STH) efficiency up to 19.27 % owing to its S-scheme mechanism and wide range of light absorption with high absorption coefficient. Our results give insights to the structure, electronic and photocatalytic properties of 2D/2D Janus BiTeCl/GeSe vdW HS and may provide a promising S-scheme photocatalyst for overall water splitting. [ABSTRACT FROM AUTHOR]

A group of MAX phases including Ti 2 AlC and Ti 2 AlN, are candidate reinforcements of Ag-based electrical contact materials. In this work, the interfacial reaction, resistivity, hardness and arc erosion resistance of Ag/Ti 2 AlX (X = C, N) were investigated comparatively. During the sintering of both Ag/Ti 2 AlX, Al deintercalated from Ti 2 AlX and Ag diffused into Ti 2 AlX. The interfacial reaction was mild in Ag/Ti 2 AlN while obvious in Ag/Ti 2 AlC. The first-principles calculation indicated that the higher vacancy formation energy of Al in Ti 2 AlN led to the mild reaction in Ag/Ti 2 AlN, which then resulted in a larger decrease in hardness and resistivity, as compared with Ag/Ti 2 AlC. Moreover, Ag/Ti 2 AlN showed superior arc erosion resistance, with less evaporation of Ag and oxidation of Ti 2 AlC. This were attributed to the lower vulnerability of mildly decomposed Ti 2 AlN, less resistance heat and easier heat dissipation, resulting from the superior electrical and thermal conductivity. • Interfacial reaction of Ag/Ti 2 AlX occurred by the diffusion of Ag into Ti 2 AlX and the outward diffusion of Al into Ag. • Higher vacancy formation energy of the Al of Ti 2 AlN contributed to less obvious interfacial reaction of Ag/Ti 2 AlN. • The interfacial reaction resulted in the increase of resistivity, and the stress relief led to the decline of hardness. • More intense reaction of Ag/Ti 2 AlC resulted in larger increase in resistivity and smaller decrease in hardness. • Mildly decomposed Ti 2 AlN and lower resistivity endowed the Ag/Ti 2 AlN with better arc erosion resistance. [ABSTRACT FROM AUTHOR]

BiCuSeO based oxide show excellent thermoelectric performance due to its low thermal conductivity and moderate Power factor. There is rare study on the same crystal structured BiCuSO with lower cost and more earth abundance. The thermoelectric performance of BiCuSO is limited by its high resistivity result from its low carrier concentration and large band gap. In this paper, p-type polycrystalline BiCuSO doped with Pb was fast prepared by one-step high pressure method and the composition dependent thermoelectric properties was studied. The electrical resistivity and Seebeck coefficient of Bi 1-x Pb x CuSO both decreased monotonically with increasing Pb content due to the increased carrier concentration. The power factor was improved and the thermal conductivity was suppressed by Pb doping. The maximum figure of merit, ZT∼0.14 @ 700 K was obtained for the Bi 0.975 Pb 0.025 CuSO sample, which makes them promising candidates for thermoelectric applications. [ABSTRACT FROM AUTHOR]

A novel magnetic Fe 3 O 4 /graphene composite (FGC) was fabricated by a facile one-step reaction route and shown to be effective for sorbing U(VI) from aqueous solution. The structure, properties and application of the prepared FGC composite were well evaluated. The high saturation magnetization (45.6 emu/g) made FGC easier to be separated from the media within several seconds under an external magnetic. Effects of different ambient conditions (i.e., pH and ionic strength, contact time, temperatures) on sorption behaviors of U(VI) on FGC were carried out by batch experiments. According to the calculation of Langmuir model, the maximum sorption capacity of U(VI) on the FGC at pH 5.5 and 298 K was 176.47 mg/g. The sorption was correlated with the effects of pH, contact time, and temperature. X-ray photoelectron spectroscopy analysis revealed that U(VI) was sorbed on FGC via oxygen-containing functional groups. This work demonstrated that FGC could be recycled and used as an effective recyclable sorbent for sorption of U(VI). [ABSTRACT FROM AUTHOR]

The ternary composite of hollow ZnFe 2 O 4 microspheres@graphene decorated with TiO 2 nanosheets was fabricated by two-step hydrothermal method. FESEM and TEM images illustrate that hollow ZnFe 2 O 4 microspheres with an average diameter of about 300–500 nm were attached to the surface of transparent graphene sheets. In addition, TiO 2 nanosheets were grown on the top of ZnFe 2 O 4 @graphene with a random orientation. Electromagnetic (EM) wave absorption results demonstrate that the maximum reflection loss (R L ) of ZnFe 2 O 4 @graphene@TiO 2 composite are significantly enhanced, which can be up to −55.6 dB at 3.8 GHz for a coating of 2.5 mm. The maximum absorbing bandwidth exceeding −10 dB is almost 6.4 GHz (2.8–5.4 GHz, 12.9–14.5 GHz, 15.8–18 GHz) at only 2.5 mm. Consequently, it is supposed that the hierarchical structure of ZnFe 2 O 4 @graphene@TiO 2 composite can be served as a promising microwave absorber, especially in low frequency. [ABSTRACT FROM AUTHOR]

Aiming at reducing the total cost in cost-sensitive learning, this paper introduces a semi-supervised learning model based on uncertainty of sample outputs. Its central idea is (1) to categorize the samples which are not in training set into several groups based on the uncertainty-magnitude of their outputs, (2) to add the group of samples which have the least uncertainty together with their predicted labels in the original training set, and (3) to retain a new classifier for total cost reduction. The ratio of costs between classes and its impact on learning system improvement is discussed. Theoretical analysis and experimental demonstration show that the model can effectively improve the performance of a cost-sensitive learning algorithm for a certain type of classifiers. [ABSTRACT FROM AUTHOR]

[Display omitted] • Few positive allosteric modulators were reported in the NTD of GluN1/N2A NMDARs. • The scaffold hopping strategy was adopted to obtain new PAMs with stable molecular skeleton. • Candidate compound 5c selectively enhanced GluN1/N2A NMDARs function. • GluN1/N2A NMDARs positive allosteric modulators could be developed neuroprotective agents. NMDA receptor subunits have differential roles in mediating excitotoxic neuronal death both in vitro and in vivo. Activation of NR2A-containing NMDA receptors promotes neuronal survival and exerts a neuroprotective action, whereas over activating GluN2B-containing receptor results in excitotoxicity, increasing neuronal apoptosis. Our previous study has identified Npam 43 as a NMDAR positive allosteric modulators. However, the cis-trans isomerization impedes the development of Npam 43 as potential neuroprotective agents. To discover more potent and selective GluN2A NMDAR positive allosteric modulators, 38 derivatives were synthesized and evaluated their neuroprotective effect on glutamate-exposed PC-12 cells. The allosteric activities of compounds were evaluated using calcium imaging approaches. Among them, compound 5c exhibit GluN1/2A selectivity over GluN1/2B and show neuroprotective activity in vitro and in vivo. This study reported a series of GluN1/2A positive allosteric modulators as neuroprotective agents, and provided a potential opportunity to discover new drugs for stroke treatment. [ABSTRACT FROM AUTHOR]

Absract Bismuth copper oxychalcogenides, BiCuChO (Ch = S, Se, Te), are facile, and rapidly synthesized by high pressure method. The Rietveld refinement of powder X-ray diffractions shows that BiCuChO compounds have a layered crystal structure with a space group of P4/nmm. All the high pressure synthesised samples show semiconductor characteristics, while BiCuTeO prepared by the conventional method displays metal conducting behavior. The conducting behavior of BiCuTeO obtained in this study originates from the low crystal defect concentrations under the effects of high pressure; evidenced by density functional theory calculations. Large Seebeck coefficient ∼600 μV/K was obtained for BiCuSO, due to its high carrier effect mass. BiCuChO exhibits extremely low thermal conductivity (<1 Wm −1 K −1 ), which decreases with an increase in the Ch 2− ion radius. The maximum figure of merit reaches 0.03, 0.31 and 0.65 for BiCuSO, BiCuSeO and BiCuTeO, respectively, values which are comparable to those for samples prepared by the conventional, complex method. [ABSTRACT FROM AUTHOR]

N-type thermoelectric materials PbTe doped with iodine (PbTe 1−x I x , x = 0.0001, 0.0003, 0.0007 and 0.001) were synthesized by high pressure and high temperature method (HPHT). Thermoelectric properties of PbTe 1−x I x are investigated in the range of 300–600 K. The carrier concentration of PbTe prepared by HPHT is more sensitive to I content compared to that of the PbTe 1−x I x sample prepared by other methods. The resistivities and the absolute values of Seebeck coefficients for PbTe 1−x I x increase while the thermal conductivities decrease with increasing temperature. A large power factor of 39.1 μW/(cmK 2 ) at room temperature is obtained with the carrier concentration of 9.7 × 10 18 cm −3 , which is much higher than that of Sb and Bi doped PbTe with the same synthesizing conditions. The high power factor is attributed to the high Hall mobility and large effective mass. The maximum figure-of-merit, ∼0.71 @ 600 K, is obtained for the samples with the carrier concentration of 9.7 × 10 18 cm −3 . [ABSTRACT FROM AUTHOR]

Polycrystalline BiCuSeO oxides are prepared by solid-state reaction followed by pressureless sintering (PLS) and high pressure sintering (HPS) methods. Both the experimental results and the density functional theory calculations indicate that the crystal defect concentrations of BiCuSeO can be reduced under the effect of high pressure. By comparing with the PLS sample, a larger power factor and a lower thermal conductivity can be obtained for the HPS sample. The maximum figure of merit ZT∼0.4 @ 800 K was obtained for the HPS sample, which is about 3 times higher than the PLS sample. These results indicate that the effect of high pressure is beneficial to modifying the microstructure and improving the thermoelectric performance of BiCuSeO oxyselenide. [ABSTRACT FROM AUTHOR]

Paracostibite (CoSbS) consists of earth-abundant and low-cost elements, which has received a lot of attention as a newly developed thermoelectric material. In this report, Se-alloyed CoSbS samples with the composition of CoSb 1−x Se x S (x ≤ 0.2) have been synthesized by the melting annealing process combined with the spark plasma sintering method. It was found that Se alloying can tune the band gap and impurity conductance activation energy of CoSbS effectively, which leads to an increased carrier concentration and an enhanced power factor. The thermal conductivity was sharply suppressed because Se alloying induced the mass fluctuation and strain field fluctuation. The maximum zT of 0.22 was achieved for CoSb 0.9 Se 0.1 S at 823 K, which is about twice that of the pristine CoSbS. In particular, the solid solution CoSb 1−x Se x S has a higher average zT than that of CoSbS 1−x Se x prepared by the same method. The research shows that the construction of antisite defect of Se Sb in CoSbS is an effective route to optimize its thermoelectric performance. [Display omitted] • CoSbS thermoelectric compound contained anti-site defect of Se Sb were synthesized. • The band gap and impurity activation energy of CoSbS decrease after Se alloying. • CoSb 1−x Se x S solid solution has higher average zT than that of CoSbS 1−x Se x. [ABSTRACT FROM AUTHOR]

Tailoring of amino acid residues is a feasible strategy to design the structure of peptide for special application. We selected poly(ethylene glycol) and α-amino acids with hydrophobic alkyl side group (L-alanine，L-valine and L-leucine) to synthesize di-block co-polypeptide. The copolymers with methyl side group self-assembled into random coil in majority and aggregated further into stable spherical nanoarchitectures with a little filament owing to the small size, less flexibility and less hydrophobicity of methyl group. By lengthening peptide block, the copolymer self-organized into overwhelming β-sheet and ordered nanorods or nanofibers due to the strengthening hydrophobicity as the copolymers with isopropyl side group did. The copolymers with isobutyl side groups showed cloudy solutions and irregular morphology because the flexibility and large size of isobutyl groups hampered the regular stacking of β-plated sheets and agglomerated into micro-sized precipitates despite of the most hydrophobicity. As temperature rising, both the transition of random coil to β-sheet and PEG dehydration contributed to the sol-gel transition for the copolymers with methyl side group, while PEG dehydration was the primary reason of sol-gel transition for the copolymers with isopropyl side group. In this article, we first disclosed the self-organization process of mPEG-b-polypeptide, which would lay the foundation for the designing of polypeptide-related materials with well-defined properties. How the alkyl side group affects the preliminary secondary structure and the further coordinated self-organized process of the polypeptide materials that we discussed in this paper. Based on the experimental results about secondary structures and morphologies of the comparable copolymers with different side groups, we proposed a three levels of organization process for the copolymers. By this mode of self-organization process, compared to the hydrophobicity, the flexibility or rigid nature of the side group, namely the variation of the side group configuration was more important to determine the stacking regularity of the β-sheet layers and therefore the stability of self-assembled basic nano-structural units and their final size of aggregating entities. [Display omitted] • Less flexible and small methyl group caused random coil. • Flexible and large isobutyl groups hampered the regular stacking of β-sheets. • Appropriate flexibility, size and hydrophobicity of alkyl side groups provoked ordered β-sheet stacking. • Transition of random coil to β-sheet and PEG dehydration induced sol-gel transition. • Ordered stacking of β-sheets stabilized polypeptide against thermal stimulus. [ABSTRACT FROM AUTHOR]

We proposed an adjoint-based inverse method and mathematical solutions using Lagrange multiplier theorem for inferring dynamic viscoelastic properties of heterogeneous structures with displacement observations to improve computation reliability and efficiency. Existing methods such as the one using finite-difference approximated gradient may not be efficient and accurate enough for considering complex situations of the coupled effects of dynamic loading, material deformation memory, and structural heterogeneity. The proposed method derives both gradient and Hessian mathematically to satisfy the first-order necessary and second-order sufficient optimal conditions, which has great advantages compared to other approaches. We also proposed robust numerical algorithms for accurate and fast computations, including a regularization to control reasonable parameter ranges, a Newton’s method with Hessian function to determine search direction for fast convenience, and a modified Armijo rule to find a stable step length. We developed a Galerkin time-domain finite-element method for numerical solutions of resulting partial differential equations, and validated the model for a layered structure under dynamic loading tests. Results indicate that the proposed method has greatly improved computation accuracy and speed as compared to existing approaches. It may be applied to a broad range of heterogeneous materials and structures at different length and time scales. [ABSTRACT FROM AUTHOR]

This paper presents a novel integrated magnetic three-port converter (IMTPC) with high power density and all three ports’ current ripple cancellation. The proposed IMTPC can interface one PV port, one bidirectional battery port, and one load port of the PV-battery dc power system. Only two high power magnetic devices are needed in an IMTPC for realizing power conversion, ripple cancellation, and switch driver simultaneously. Three extra capacitors were added to achieve three ports’ current ripple cancellation. Therefore, the port of the IMTPC will always in continuous-conduction mode with “zero current ripple,” thus, size of passive filter can be reduced and accuracy of maximum power point tracking can be improved. Meanwhile, simple driving of the high-side switch can be realized by integrated magnetic winding, which is responsible for MOSFET driver's voltage level shift. The using of the integrated magnetic technique not only performs aforementioned advantages but also shows great potential for reducing the weight and volume of the dc–dc converter. Finally, experimental verifications are given to illustrate the feasibility and effectiveness of the proposed topology and control method. [ABSTRACT FROM PUBLISHER]

In order to interface one photovoltaic (PV) port, one bidirectional battery port, and one load port of a PV-battery dc power system, a novel nonisolated three-port dc/dc converter named boost bidirectional buck converter (B3C) and its control method based on three-domain control are proposed in this paper. The power flow and operating principles of the proposed B3C are analyzed in detail, and then, the dc voltage relation between three ports is deduced. The proposed converter features high integration and single-stage power conversion from both PV and battery ports to the load port, thus leading to high efficiency. The current of all three ports is continuous; hence, the electromagnetic noise can be reduced. Furthermore, the control and modulation method for B3C has been proposed for realizing maximum power point tracking (MPPT), battery management, and bus voltage regulation simultaneously. The operation can be transited between conductance mode and MPPT mode automatically according to the load power. Finally, experimental verifications are given to illustrate the feasibility and effectiveness of the proposed topology and control method. [ABSTRACT FROM PUBLISHER]