43 results on '"Xiaoxia Zheng"'
Search Results
2. Controllable synthesis of non-layered two-dimensional plate-like CuGaSe2 materials for optoelectronic devices
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Wenling Feng, Yutong Zhao, Xiaoxia Zheng, Wenjian Wang, Xu Wang, Zenghao Xia, Wenliang Wang, Di Zhao, and Weihua Wang
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Fabrication ,Materials science ,business.industry ,General Chemical Engineering ,General Chemistry ,Photoelectric effect ,Uniform size ,Characterization (materials science) ,Solar energy storage ,Crystallinity ,Solar energy conversion ,Optoelectronics ,Absorption (electromagnetic radiation) ,business - Abstract
CuGaSe2 semiconductor materials, as an important member of the I–III–VI2 family, have sparked tremendous attention due to their fascinating structure-related properties and promising applications in solar energy storage and conversion. Nevertheless, the controllable preparation of two-dimensional (2D) CuGaSe2 structures is still a daunting challenge owing to the intrinsic non-layered crystal structure and inaccessible reactivity-matching of multiple reaction precursors, which will seriously impede the much deeper research progress on their properties and applications. Herein, non-layered 2D CuGaSe2 plates possessing high crystallinity, and uniform size and morphology have been first synthesized by a feasible cation exchange strategy. Because the fabrication of 2D CuGaSe2 crystals is rarely reported, a particular highlight is laid on the compositional analysis, structural characterization, and formation mechanism. Furthermore, the optical absorption and optoelectronic measurements reveal that the as-synthesized CuGaSe2 plates exhibit high light harvesting capacity and excellent photoelectric performance. This study opens up a new avenue for the feasible fabrication of non-layered CuGaSe2 plates possessing a high-quality crystalline structure and provides a promising candidate for the development of novel solar energy conversion and storage devices.
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- 2021
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3. miR-132 serves as a diagnostic biomarker in gestational diabetes mellitus and its regulatory effect on trophoblast cell viability
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Xuegui Zhou, Cuiping Xiang, and Xiaoxia Zheng
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0301 basic medicine ,Adult ,Male ,Pathology ,medicine.medical_specialty ,Trophoblast cell ,Histology ,endocrine system diseases ,Cell Survival ,Placenta ,Proliferation ,Gestational diabetes mellitus ,Pathology and Forensic Medicine ,Andrology ,03 medical and health sciences ,miR-132 ,0302 clinical medicine ,Cell Movement ,Pregnancy ,Diagnosis ,medicine ,lcsh:Pathology ,Humans ,Cell Proliferation ,Receiver operating characteristic ,business.industry ,Cell growth ,Research ,Area under the curve ,General Medicine ,Transfection ,medicine.disease ,female genital diseases and pregnancy complications ,Trophoblasts ,Gestational diabetes ,Diabetes, Gestational ,MicroRNAs ,030104 developmental biology ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Biomarker (medicine) ,Female ,business ,Biomarkers ,MicroRNA-132 ,lcsh:RB1-214 - Abstract
Background Gestational diabetes mellitus (GDM) leads to poor pregnancy outcomes. Strategies that improve trophoblast cell function are important methods for GDM treatment. This study aimed to investigate the expression and diagnostic potential of microRNA-132 (miR-132) in GDM patients, and further analyzed the effects of miR-132 on HTR-8/SVneo cell proliferation. Methods Quantitative real-time PCR was applied to estimate the expression of miR-132. A receiver operating characteristics curve (ROC) analysis was performed to evaluate the diagnostic value of serum miR-132 in GDM patients. In vitro regulation of miR-132 in trophoblast cell HTR-8/SVneo was achieved by cell transfection, and the effects of miR-132 on cell proliferation were assessed using CCK-8 assay. Results Expression of miR-132 was decreased in serum and placenta tissues in GDM patients compared with the healthy women. A negative correlation was found between the serum miR-132 levels and fasting blood glucose of the GDM patients. A ROC curve shown the serum miR-132 had considerable diagnostic accuracy with an area under the curve (AUC) of 0.898. High glucose (HG) treatment induced an inhibition in HTR-8/SVneo cell proliferation and the expression of miR-132. The overexpression of miR-132 in HTR-8/SVneo cells could markedly rescued the HG - induced suppressed cell proliferation. Conclusion All the data of this study revealed the reduced expression of miR-132 in serum and placenta tissues of GDM, and serum miR-132 serves a candidate biomarker in the diagnosis of GDM. miR-132 may act a protective role against GDM via enhancing the trophoblast cell proliferation.
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- 2019
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4. Broadband visible metamaterial absorber based on a three-dimensional structure
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Xinyan Ling, Zhongyin Xiao, Xiaoxia Zheng, and Chuan Li
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Materials science ,business.industry ,General Engineering ,Structure (category theory) ,Physics::Optics ,General Physics and Astronomy ,02 engineering and technology ,01 natural sciences ,Physics::History of Physics ,010305 fluids & plasmas ,020303 mechanical engineering & transports ,0203 mechanical engineering ,0103 physical sciences ,Broadband ,Metamaterial absorber ,Optoelectronics ,business - Abstract
In this paper, a broadband metamaterial absorber is successfully designed by a three-dimensional structure. And the three-dimensional absorber is just obtained by a two-dimensional structure which ...
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- 2018
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5. Design of a broadband, wide-angle metamaterial absorber base on hybrid structure
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Xinyan Ling, Chuan Li, Xiaoxia Zheng, Huanling Zou, Zhongyin Xiao, and Wei Li
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010302 applied physics ,Materials science ,business.industry ,Structure (category theory) ,Physics::Optics ,General Physics and Astronomy ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Base (topology) ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,0103 physical sciences ,Broadband ,Metamaterial absorber ,Optoelectronics ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Broadband absorption ,Layer (electronics) - Abstract
In this paper, we presented and investigated a special metamaterial absorber to achieve broadband absorption. Firstly, we proposed a two-dimensional (2D) structure, which include a hybrid layer on ...
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- 2017
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6. Tunable terahertz metamaterial absorber and the sensing application
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Xinyan Ling, Zhongyin Xiao, and Xiaoxia Zheng
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010302 applied physics ,Permittivity ,Materials science ,business.industry ,Terahertz radiation ,02 engineering and technology ,Molar absorptivity ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Split-ring resonator ,chemistry.chemical_compound ,Optics ,chemistry ,0103 physical sciences ,Strontium titanate ,Metamaterial absorber ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Absorption (electromagnetic radiation) ,Electrical impedance - Abstract
In this paper, a tunable terahertz metamaterial absorber is proposed, and the resonant frequency can be controlled by the variation of temperature and the permittivity. For the top layer of the absorber, which consist of a split ring resonator (SRR), and substrate strontium titanate dielectric layer was filled into the two slits of the SRR. The simulated results show that the absorber has a distinct absorption peak at f = 1.26 THz for T = 300 K, which is close to the calculated resonant frequency fm ≈ 1.268 THz, and the absorptivity can achieve 99.93%. To explain the physical mechanism of the absorption, the relative impedance, the surface current and equivalent LC-circuit are analyzed, which could further demonstrate that the magnetic resonant play a major role for the absorption. Moreover, the resonant point will produce a blue-shift with the increase of the temperature, and a red-shift will be appeared with the varying of the permittivity, so that the tunable metamaterial absorber has an application in sensing.
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- 2017
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7. Elevated expression of MMP-2 and TIMP-2 cooperatively correlates with risk of lung cancer
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Tianwen Lai, Chao Cao, Zhaichun Deng, Xiaoxia Zheng, Ning Xu, Xiaoping Huang, and Wenxue Zhang
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0301 basic medicine ,medicine.medical_specialty ,Pathology ,diagnosis ,Pulmonary disease ,Disease ,03 medical and health sciences ,TIMP-2 ,0302 clinical medicine ,Internal medicine ,Medicine ,Respiratory system ,Lung cancer ,MMP-2 ,business.industry ,respiratory system ,medicine.disease ,respiratory tract diseases ,Respiratory Medicine ,lung cancer ,030104 developmental biology ,Oncology ,030220 oncology & carcinogenesis ,Biomarker (medicine) ,biomarker ,Differential diagnosis ,business ,Lung tissue ,Research Paper - Abstract
// Chao Cao 1 , Ning Xu 1 , Xiaoxia Zheng 1 , Wenxue Zhang 1 , Tianwen Lai 2 , Zaichun Deng 3 and Xiaoping Huang 1 1 Department of Respiratory Medicine, Ningbo First Hospital, Ningbo, China 2 Department of Respiratory, Institute of Respiratory Diseases, The Affiliated Hospital of Guangdong Medical University, Zhanjiang, China 3 Department of Respiratory Medicine, Affiliated Hospital, Ningbo University School of Medicine, Ningbo, China Correspondence to: Xiaoping Huang, email: xiaopinghuang@126.com Zaichun Deng, email: dengzaichun982136@hotmail.com Tianwen Lai, email: laitianwen2011@163.com Keywords: MMP-2, TIMP-2, lung cancer, diagnosis, biomarker Received: March 24, 2017 Accepted: July 30, 2017 Published: August 11, 2017 ABSTRACT Lung cancer is one of the most common form of malignant diseases and the leading cause of cancer-related mortality worldwide. It is reported that approximately two-thirds of lung cancer patients is the presence of advance disease at the time of diagnosis. Hence novel lung cancer diagnostic tests, which can be used to screen individuals at high risk, are required. In the derivation cohort, a total of 88 patients admitted into hospital with suspected lung cancer were included. Bronchial alveolar lavage fluid (BALF) and lung tissue samples were collected from included patients, and were analyzed for MMP-2 and TIMP-2 expression. The results showed a higher level of MMP-2 and TIMP-2 expression and secretion in airways of lung cancer patients than that of benign diseases. A statistically significant correlation was observed between MMP-2 and TIMP-2. In addition, a validation cohort involving 107 patients was conducted to confirm these results. Interesting, BALF MMP-2 and TIMP-2 showed a high sensitivity and specificity in predicting the malignant nature of pulmonary disease in both derivation cohort and validation cohort. The findings in this study suggested that elevated expression of MMP-2 and TIMP-2 cooperatively correlates with risk of lung cancer. Measurement of MMP-2 and TIMP-2 in BALF might be helpful for differential diagnosis of primary lung cancer.
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- 2017
8. Broadband visible perfect absorber for sensor based on ultra-thin metamaterial
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Zhongyin Xiao, Xinyan Ling, and Xiaoxia Zheng
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010302 applied physics ,Permittivity ,Power loss ,Materials science ,business.industry ,Impedance matching ,Metamaterial ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Polarization (waves) ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Total thickness ,Optics ,0103 physical sciences ,Broadband ,Metamaterial absorber ,Optoelectronics ,Electrical and Electronic Engineering ,0210 nano-technology ,business - Abstract
A metamaterial perfect absorber having a hybrid layer and total thickness of 50 nm is demonstrated in this paper. The results indicate that a broadband absorption above 90% is achieved from 421.2 to 671.8 THz and the absorption of 99.8% can be obtained at the absorption peaks. The absorption is also illustrated to be polarization insensitive under vertical incidence. Furthermore, the broadband and high-efficient absorption are sustained over a wide incident angle range. In addition, the impedance matching theory, surface current distributions, and power loss at the resonant frequencies are also discussed. Moreover, this study demonstrates the application of different permittivity on the performance of the sensor.
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- 2017
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9. Magnesium Sulfate in combination with Nifedipine in the treatment of Pregnancy-Induced Hypertension
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Cuiping Xiang, Xuegui Zhou, and Xiaoxia Zheng
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medicine.medical_specialty ,030219 obstetrics & reproductive medicine ,Proteinuria ,business.industry ,Magnesium ,Therapeutic effect ,Blood viscosity ,chemistry.chemical_element ,Umbilical artery ,General Medicine ,030204 cardiovascular system & hematology ,Gastroenterology ,03 medical and health sciences ,0302 clinical medicine ,Blood pressure ,Nifedipine ,chemistry ,Edema ,Internal medicine ,medicine.artery ,medicine ,medicine.symptom ,business ,medicine.drug - Abstract
Objective: To investigate the effect of magnesium sulfate combined with nifedipine in the treatment of pregnancy-induced hypertension syndrome (PIHS). Methods: Total 118 pregnant women with PIHS who were admitted to our hospital from April 2017 to June 2018 were randomly divided into control group (59 cases) and observation group (59 cases). The observation group was treated by magnesium sulfate in combination with nifedipine, while the control group was treated by magnesium sulfate. The therapeutic effect, serum leukaemia inhibitory factor (LIF), Apelin level, blood pressure, blood viscosity, urinary protein, S/D and Umbilical Artery Resistance Index (UARI) were compared between the two groups. Results: The effective rate of the observation group was 94.9%, higher than 83.1% of the control group, and the difference was statistically significant (P
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- 2019
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10. OLFM4 Inhibits Epithelial-Mesenchymal Transition and Metastatic Potential of Cervical Cancer Cells
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Meng Wan, Hong Zhang, Juan Li, Qing Sun, Hongchun Hou, Xuemei Jie, Xiaoxia Zheng, Chunyan Liu, Dawei Li, Jingjing Li, and Pengju Zhang
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0301 basic medicine ,Cancer Research ,Epithelial-Mesenchymal Transition ,Down-Regulation ,Uterine Cervical Neoplasms ,Tumor initiation ,OLFM4 ,Article ,law.invention ,Metastasis ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Downregulation and upregulation ,law ,Cell Movement ,Granulocyte Colony-Stimulating Factor ,Medicine ,Humans ,Neoplasm Invasiveness ,Epithelial–mesenchymal transition ,Neoplasm Metastasis ,PI3K/AKT/mTOR pathway ,Epithelial–mesenchymal transition (EMT) ,business.industry ,TOR Serine-Threonine Kinases ,Cell migration ,General Medicine ,Phosphatidic acid ,030104 developmental biology ,Oncology ,chemistry ,030220 oncology & carcinogenesis ,Cancer research ,Cervical cancer ,mTOR ,Suppressor ,Female ,Signal transduction ,business ,HeLa Cells ,Signal Transduction - Abstract
OLFM4 has been shown to play an important role in tumor initiation and progression. This study aims to investigate the role of OLFM4 in metastatic cervical cancer and its underlying mechanism. Here we discover that OLFM4 expression is significantly reduced in metastatic cervical cancer. Accordingly, overexpression of OLFM4 inhibits epithelial‐mesenchymal transition (EMT), migration, and invasion in human cervical cancer cells. To further explore its molecular mechanisms, we reveal that OLFM4 augmentation interferes with mTOR signaling pathway, and the suppressive effects of OLFM4 on cell migration and invasion are largely weakened by phosphatidic acid (PA)-induced mTOR signal activation, which implicates the potential role of the mTOR pathway in OLFM4-related cervical metastasis. In conclusion, our results confirm OLFM4 as a tumor suppressor that inhibits cervical cancer metastasis by regulating mTOR signal pathway.
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- 2019
11. A Tunable Hybrid Metamaterial Reflective Polarization Converter Based on Vanadium Oxide Film
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Xinyan Ling, Xiaoxia Zheng, and Zhongyin Xiao
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Phase transition ,Materials science ,business.industry ,Biophysics ,Metamaterial ,02 engineering and technology ,Conductivity ,021001 nanoscience & nanotechnology ,Polarization (waves) ,01 natural sciences ,Biochemistry ,Vanadium oxide ,010309 optics ,Optics ,0103 physical sciences ,Broadband ,0210 nano-technology ,business ,Biotechnology - Abstract
A metamaterial reflective converter with vanadium oxide (VO2) film is investigated in this paper. The results indicate that a broadband polarization conversion ratio (PCR) above 90% is achieved from 4.95 to 9.39 THz and the PCR above 98.9% can be obtained at the three peaks. And the hybrid metamaterial converter is demonstrated for realizing temperature tuned electromagnetic properties. The different temperatures across the insulator-to-metal phase transition of the VO2 film can change the conductivity. Furthermore, the broadband and high-efficiency polarization conversion changes obviously with the temperature changing. In addition, this study demonstrates the application of different temperatures on the performance of the sensor. Moreover, surface current distributions at the resonant frequency are also discussed.
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- 2017
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12. A Three-Dimensional Broadband Infrared Metamaterial Absorber Based on the Plasmonic and Dipole Resonance Responses
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Xinyan Ling, Xiaoxia Zheng, and Zhongyin Xiao
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Electromagnetic field ,Resistive touchscreen ,Materials science ,business.industry ,Biophysics ,Physics::Optics ,Metamaterial ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Polarization (waves) ,01 natural sciences ,Biochemistry ,Electromagnetic radiation ,010309 optics ,Dipole ,Optics ,0103 physical sciences ,Metamaterial absorber ,Optoelectronics ,0210 nano-technology ,business ,Plasmon ,Biotechnology - Abstract
In this paper, a three-dimensional, polarization-insensitive broadband metamaterial absorber in the infrared region is proposed. And the same kind of metal is used in the whole structure. The simulated results show that the structure can achieve a broadband absorption greater than 90% from 40.3 to 70.2 THz for either transverse electric or magnetic polarization mode at normal incidence. Subsequently, due to the rotationally symmetric distributions of the structure in the z-axis, the proposed metamaterial absorber is independent for the different polarization angles. Moreover, unlike previous resistive films metamaterial absorbers which are based on the resistive film for the absorption of the electromagnetic waves, and in this structure, the absorption are not based on the metal films themselves but based on resonance. In addition, through analysis of the electromagnetic field and the surface current distributions, it can demonstrate that the absorption mechanism of the absorber which is based on the surface plasmonic and dipole resonance responses. Finally, we believe this idea also extends to other frequency regions and also can realize broadband absorption.
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- 2016
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13. Broadband and polarization-insensitive metamaterial absorber based on hybrid structures in the infrared region
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Kaikai Xu, Zhongyin Xiao, Xiaoxia Zheng, Jingyao Tang, and Xinyan Ling
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Electromagnetic field ,Materials science ,business.industry ,Infrared ,Terahertz radiation ,Physics::Optics ,02 engineering and technology ,Dielectric ,021001 nanoscience & nanotechnology ,Polarization (waves) ,01 natural sciences ,Electromagnetic radiation ,Atomic and Molecular Physics, and Optics ,010309 optics ,Optics ,0103 physical sciences ,Broadband ,Metamaterial absorber ,Optoelectronics ,0210 nano-technology ,business - Abstract
In this work, a new type of metamaterial absorber is proposed in the infrared region. This structure consists of metal-dielectric-metal. But the difference is that a square groove in the dielectric has been dug, and replaced by a metal. The simulated results show that this structure can achieve a broadband absorption. And the absorption bandwidth can be realized from 60.5 to 115.5 THz when the absorption efficiency is larger than 90%. And this structure is polarization-insensitive for incident electromagnetic waves. In addition, the structure can also achieve better absorption effect for a large incident angle, especially for TM polarized wave. What is more, a remarkably enhanced bandwidth can be realized by using a metal to fill the square groove which is dug in the dielectric. To further explain the mechanism of high absorption, the distribution of the electromagnetic field and power loss density at the resonance frequencies are analysed. And these novel properties make the absorbers have many a...
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- 2016
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14. Ultra-broadband metamaterial absorber based on the structure of resistive films
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Xinyan Ling, Xiaoxia Zheng, Kaikai Xu, Jingyao Tang, and Zhongyin Xiao
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Resistive touchscreen ,Brewster's angle ,Materials science ,Absorption spectroscopy ,business.industry ,Physics::Optics ,General Physics and Astronomy ,Absorption effect ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Polarization (waves) ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,010309 optics ,symbols.namesake ,Optics ,0103 physical sciences ,Broadband ,Vertical direction ,symbols ,Metamaterial absorber ,Electrical and Electronic Engineering ,0210 nano-technology ,business - Abstract
This paper presents a three-dimensional structure of metamaterial absorber, and the unit of the absorber is composed of six different size resistive films which are placed on the metal plane ground. The simulated results show that the absorber can realize ultra-broadband absorption, which is from 38 to 142 GHz when the absorption is larger than 90%. And the relative absorption bandwidth can achieve 115.5%. In addition, the proposed metamaterial absorber is polarization-insensitive, which has the same absorption spectra for TE and TM polarization waves. And the absorber has large incident and polarization angles. In the end, the power loss density is analyzed. Through observing the distribution of power loss density, a polarization-controlled metamaterial absorber can be implemented if subtract the resistance film of the horizontal direction or the vertical direction subtracted. And the polarization-controlled metamaterial absorber also has ultra-broadband absorption effect. We believe that the abs...
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- 2016
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15. Broadband asymmetric transmission characteristics based on metamaterial in terahertz region
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Siheng Ren, Wang Xiaomin, Baoping Yang, Jinqiang Fan, Xiaoxia Zheng, Dongjie Zhao, and Guoqiang Shang
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Physics ,History ,Transmission (telecommunications) ,business.industry ,Terahertz radiation ,Broadband ,Optoelectronics ,Metamaterial ,business ,Computer Science Applications ,Education - Abstract
In this paper, a multi-layered terahertz metamaterial has been proposed, which consisted of dual-layered substrate and three 6-shaped meta-layered. Numerical results reveal that the structure realizes broadband asymmetric transmission of linearly polarized wave. In particular, this structure realizes a maximum of 0.95 for asymmetric transmission at 6.7THz. Based on the electric fields, we have analyzed the wave conversion of linearly polarized wave and the mechanism of asymmetric transmission effect.
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- 2020
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16. Analysis on the level of IL-6, IL-21, AMH in patients with auto-immunity premature ovarian failure and study of correlation
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Ruiqin Yue, Hong Chen, Chuanyan Ma, Shulan Sun, and Xiaoxia Zheng
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0301 basic medicine ,endocrine system ,Cancer Research ,medicine.medical_specialty ,endocrine system diseases ,03 medical and health sciences ,Basal (phylogenetics) ,Follicle-stimulating hormone ,0302 clinical medicine ,Immunology and Microbiology (miscellaneous) ,Internal medicine ,medicine ,Testosterone ,030219 obstetrics & reproductive medicine ,biology ,business.industry ,Anti-Müllerian hormone ,General Medicine ,medicine.disease ,Antral follicle ,female genital diseases and pregnancy complications ,Premature ovarian failure ,030104 developmental biology ,Endocrinology ,biology.protein ,Luteinizing hormone ,business ,hormones, hormone substitutes, and hormone antagonists ,Hormone - Abstract
Expression of interleukin-6 (IL-6), interleukin-21 (IL-21) and anti-mullerian hormone (AMH) in premature ovarian failure (POF) patients were observed to explore the correlation of each indicator and its significance in POF. One hundred and forty-two patients diagnosed with POF in Binzhou City Center Hospital from June 2014 to December 2015 were selected as the observation group. At the same time, another 140 healthy women were selected as the control group. The serum levels of IL-6, IL-2l, AMH, follicle stimulating hormone (FSH) and luteinizing hormone (LH), estradiol (E2), testosterone (T) and basal antral follicle count (AFC), and mean ovarian volume (MOV) were determined and compared; correlation analysis of IL-6, IL-2l and AMH with other indicators was performed. Compared to the control group, the serum levels of IL-6, IL-21, FSH and LH in the observation group were significantly higher (P
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- 2018
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17. Research on the Design of CORDIC Vector Magnitude Calculator by using Model-Based Design
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Yang Nie, Cao Jianying, and Xiaoxia Zheng
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business.industry ,Computer science ,Magnitude (mathematics) ,Fixed point ,Computational science ,law.invention ,Computer Science::Hardware Architecture ,Calculator ,Simple (abstract algebra) ,law ,Signal Processing ,Scalability ,Model-based design ,CORDIC ,business ,Computer hardware ,Euclidean vector - Abstract
Vector magnitude calculation is significant in the QR-algorithm by Coordinate Rotation Digital Computer (CORDIC), which is increasingly used in adaptive applications. However, its hardware implementation is extremely difficult. In this paper, a fixed point CORDIC system is constructed to compute the magnitude of a vector by using Model-Based Design. The simulation results show that the proposed method of CORDIC vector magnitude calculator is not only simple in structure and easy to implement, and can improve the speed of operation with good scalability.
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- 2015
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18. A tunable reflective polarization converter based on hybrid metamaterial
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Zhongyin Xiao, Xinyan Ling, Xiaoxia Zheng, Lei Wang, and Huanling Zou
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Materials science ,business.industry ,Terahertz radiation ,Physics::Optics ,Metamaterial ,02 engineering and technology ,Dielectric substrate ,Polarizer ,021001 nanoscience & nanotechnology ,Polarization (waves) ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,010309 optics ,Resonator ,Optics ,Vanadium dioxide ,law ,0103 physical sciences ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Circular polarization - Abstract
A hybrid metamaterial converter based on a hybrid layer, a gold (Au) film and a dielectric substrate is proposed to realize linear and circular polarization conversions in the terahertz (THz) band. The hybrid layer is composed of a vanadium dioxide (VO2) plane and I-shaped resonators. The polarization conversion ratio (PCR) above 90% is achieved in a broad band range from 2.10 to 5.03 THz under both linearly and circularly polarized waves. And, the PCR is up to near unity around the resonant frequency. Meanwhile, the metamaterial convertor is sensitive to the incident angles. Moreover, a controlled modulation characteristic can be realized by the proposed polarization converter. In addition, the physical mechanism of the polarization conversion is analyzed by the distributions of surface currents. These features pave a novel way for the broad band polarization converter and hold application in the area of sensing, THz communication and tunable polarizers.
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- 2017
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19. An ultra-broadband metamaterial absorber based on the hybrid materials in the visible region
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Zhongyin Xiao, Xinyan Ling, and Xiaoxia Zheng
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Materials science ,business.industry ,Plane (geometry) ,Indium antimonide ,Physics::Optics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,010309 optics ,chemistry.chemical_compound ,Optics ,Semiconductor ,chemistry ,Electric field ,0103 physical sciences ,Broadband ,Metamaterial absorber ,Optoelectronics ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Absorption (electromagnetic radiation) ,Energy harvesting - Abstract
In this paper, an ultra-broadband metamaterial absorber is successfully designed in the visible region. The structure of the absorber is just obtained by the two-dimensional plane structure which rotate 90° along x-axis. Furthermore, the formation of the structure for the hybrid materials is based on the four U-shaped structure of the metal titanium is embedded in the semiconductor (indium antimonide). The simulated results show that the proposed metamaterial absorber can achieve an ultra-broadband absorption with greater than 90% from 252.2 to 822.3 THz, and the relative absorption bandwidth gets to 106.1%. Finally, the simulated electric field, surface current and power loss density distributions further illustrate the absorption mechanism of the metamaterial absorber. And we believe the metamaterial absorber will have many potential applications in energy harvesting and stealth devices.
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- 2017
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20. Overexpression of GOLPH3 protein is associated with worse prognosis in patients with epithelial ovarian cancer
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Binghui Sun, Xiuxia Wang, Hongtao Lv, Fengnian Rong, Xiaoxia Zheng, Yingchun Ma, and Yuanhong Wu
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Adult ,Oncology ,medicine.medical_specialty ,Gene Expression ,Carcinoma, Ovarian Epithelial ,Pathogenesis ,Internal medicine ,medicine ,Humans ,Epithelial ovarian cancer ,Neoplasms, Glandular and Epithelial ,Neoplasm Metastasis ,Lymph node ,Aged ,Neoplasm Staging ,Ovarian Neoplasms ,Proportional hazards model ,business.industry ,Hazard ratio ,Membrane Proteins ,Cancer ,Histology ,General Medicine ,Middle Aged ,Prognosis ,medicine.disease ,Immunohistochemistry ,medicine.anatomical_structure ,Female ,Neoplasm Grading ,business - Abstract
Golgi phosphoprotein 3 (GOLPH3) has important roles in the pathogenesis of cancer, and overexpression of GOLPH3 has been found in several kinds of cancers. However, the relationship between GOLPH3 overexpression and prognosis in patients with epithelial ovarian cancer remains unknown. This study aimed to investigate the relationship between GOLPH3 overexpression and overall survival in patients with epithelial ovarian cancer. The expression of GOLPH3 protein in tumor tissue was evaluated using immunohistochemistry. Seventy-five patients with epithelial ovarian cancer with the data of GOLPH3 expression and follow-up were included. GOLPH3 overexpression was significantly associated with advanced stage, histology, high grade, and lymph node metastases (P
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- 2014
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21. A comparison of reading comprehension across paper, computer screens, and tablets: Does tablet familiarity matter?
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Wei Cheng, Guang Chen, Ting-Wen Chang, Xiaoxia Zheng, and Ronghuai Huang
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Multimedia ,Computer science ,business.industry ,media_common.quotation_subject ,Educational technology ,Usability ,computer.software_genre ,Computer Science Applications ,Education ,Comprehension ,Interactivity ,Reading comprehension ,Reading (process) ,Screen reading ,business ,computer ,Multiple choice ,Cognitive psychology ,media_common - Abstract
Nowadays, reading on screens is an essential part of our daily life. Tablet computers, with great portability, usability, and interactivity, have become a popular mobile device for learning and reading. However, there were few studies to explore the effects on reading using tablet computers, and the difference between computer-based reading and paper-based reading is still not clear. Therefore, this study focused on to investigate the effects of reading comprehension across paper, tablets, and computers. Moreover, the user familiarity was regarded as a potential issue to affect the reading on digital devices. Accordingly, this study took into account to figure out the effects and impacts of the user familiarity on reading comprehension while reading on tablets. Two question types of reading comprehension, multiple choice questions as the shallow level comprehension and summarization as deep level comprehension, were considered to test the reading comprehension. Data from 90 college students were used in the data analysis. It was indicated that the paper group performed significantly better than the computer-based reading on the shallow level comprehension. This finding confirmed and eliminated the factors of reading in paper and computer for the previous studies. For example, the way of navigation was still the main reason to affect the process of reading. However, the switch between the reading and test media was not the reason to affect the reading comprehension. In order to figure out why there was no difference between tablets and the other two media platforms, the tablet familiarity was evaluated to find out whether the familiarity affect reading comprehension or not. The result showed that the high level of tablet familiarity group performed significantly better than low level group on deep level comprehension. For this result, it could conclude that if providing students enough and appropriate training, they could have higher familiarity with tablets and then gain better reading comprehension using tablets.
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- 2014
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22. A three-dimensional ultra-broadband metamaterial absorber in terahertz region
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Kaikai Xu, Xinyan Ling, Jingyao Tang, Xiaoxia Zheng, and Zhongyin Xiao
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010302 applied physics ,Brewster's angle ,Materials science ,business.industry ,Infrared ,Terahertz radiation ,Physics::Optics ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Polarization (waves) ,01 natural sciences ,Electromagnetic radiation ,symbols.namesake ,Magnetization ,Optics ,0103 physical sciences ,Metamaterial absorber ,symbols ,Optoelectronics ,General Materials Science ,0210 nano-technology ,business ,Microwave - Abstract
In this paper, we proposed a three-dimensional metamaterial absorber with ultra-broadband in terahertz region. Compared with other three-layer structures, our structure is only composed of graphite film and a metal plate. The simulated results show that the metamaterial absorber can achieve an ultra-broadband absorption more than 90 % from 3 to 9 THz for either transverse electric or magnetic polarization wave at normal incidence. In addition, the absorption properties based on the oblique incidence and different polarization angles are also observed. A good absorption bandwidth can be kept when the incidence angle is up to 60°. Moreover, the absorber is polarization-insensitive with the polarization angle increase. Finally, the power loss density and surface current distributions at distinct resonance point are analyzed, which can demonstrate that the graphite plays an important role for the absorption of electromagnetic waves. We believe that the design idea of the three-dimensional metamaterial absorber maybe can extend to microwave, infrared or optical region.
- Published
- 2016
- Full Text
- View/download PDF
23. Broadband and efficient reflective polarization converter based on a three-dimensional metamaterial
- Author
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Xinyan Ling, Zhongyin Xiao, and Xiaoxia Zheng
- Subjects
Physics ,Polarization rotator ,business.industry ,Linear polarization ,Terahertz radiation ,Physics::Optics ,Metamaterial ,02 engineering and technology ,Dielectric ,Elliptical polarization ,021001 nanoscience & nanotechnology ,Polarization (waves) ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Optics ,0103 physical sciences ,Optoelectronics ,Electrical and Electronic Engineering ,010306 general physics ,0210 nano-technology ,business ,Ground plane - Abstract
In this paper, a three-dimensional metamaterial was proposed to realize a broadband and efficient polarization conversion. The unit cell of the three-dimensional metamaterial is composed of pseudo-planar structure and a ground plane separated by a dielectric spacer. The linear polarization of incident waves can be converted to its orthogonal direction upon reflection. The simulated results show that the polarization conversion ratio of more than 95 % is observed in the broad frequency range from 7.39 to 13.87 THz. The novel pseudo-planar reflective polarization converter can improve the magnitude of the polarization conversion ratio compared to previous works. To explain the mechanism of the proposed structure, the surface current distributions are investigated. In addition, the right-hand circularly polarized incident waves can also be converted to left-hand circularly polarized wave with broadband and efficient polarization conversion. The proposed metamaterial provides an alternative platform to promote potential applications in the terahertz region.
- Published
- 2016
- Full Text
- View/download PDF
24. Ultra-broadband reflective polarization converter using ring-chain metamaterial
- Author
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Kaikai Xu, Xiaoxia Zheng, Zhongyin Xiao, Xinyan Ling, and Jingyao Tang
- Subjects
Materials science ,Polarization rotator ,business.industry ,Terahertz radiation ,Bandwidth (signal processing) ,Tunable metamaterials ,Metamaterial ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Polarization (waves) ,01 natural sciences ,010309 optics ,Optics ,0103 physical sciences ,Broadband ,0210 nano-technology ,business - Abstract
In this work, a novel bi-layered metamaterial structure composed of a ring-chain structure and metal sheet-backed is proposed, which can realize ultra-broadband reflected polarization conversion in the near-infrared spectral region. Numerical results reveal that the structure possesses the ability to convert x-polarized and y-polarized waves to their orthogonal direction in frequency range from 109.5 to 338.8 THz, and the polarization conversion ratio can reach 99%. Based oncurrent density, the physical mechanism of polarization conversion is investigated at the resonant frequency. What is more, the resonant frequencies can be tunable with the change of the structure parameters. In addition, the polarization conversion of this structure is sensitive to the incident angle.
- Published
- 2016
- Full Text
- View/download PDF
25. Asymmetric transmission of both linearly and circularly polarized waves in multi-layered meta-surface
- Author
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Jingyao Tang, Xinyan Ling, Xiaoxia Zheng, Zhongyin Xiao, and Kaikai Xu
- Subjects
Surface (mathematics) ,Physics ,Linear polarization ,business.industry ,Metamaterial ,02 engineering and technology ,Dielectric substrate ,Microwave frequency ,021001 nanoscience & nanotechnology ,01 natural sciences ,Molecular physics ,Optics ,Transmission (telecommunications) ,0103 physical sciences ,010306 general physics ,0210 nano-technology ,business - Abstract
In this paper, we propose and demonstrate a multi-layered chiral structure consisting of a y-shape, a half-gammadion and an S-shape which possesses the property of asymmetric transmission for both linearly and circularly polarized waves in microwave frequency band. Numerical simulated results indicate that the chiral structure realizes a maximum asymmetric transmission of 0.88 and 0.31 for circularly and linearly polarized waves, respectively, which exhibit magnitude improvement over previous chiral metamaterials. Specifically, the maximum asymmetric transmitted coefficient of the designed structure is insensitivity to the incident angles at the resonance frequency. Additionally, we also study the influence of dielectric substrate thickness on the asymmetric transmission effect in detail.
- Published
- 2016
- Full Text
- View/download PDF
26. A broadband and polarization-insensitive metamaterial absorber
- Author
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Kaikai Xu, Xiaoxia Zheng, Zhongyin Xiao, Jingyao Tang, and Xinyan Ling
- Subjects
Materials science ,Terahertz radiation ,business.industry ,Bandwidth (signal processing) ,Metamaterial ,02 engineering and technology ,Polarization (waves) ,Electromagnetic radiation ,Resonator ,020210 optoelectronics & photonics ,Optics ,Broadband ,0202 electrical engineering, electronic engineering, information engineering ,Metamaterial absorber ,business - Abstract
In this work, a broadband and polarization-insensitive absorber with split-ring resonator in the infrared region is proposed. The structure is composed of three layers, in which material of first layer is low-conductivity alloy. The simulated result reveals that the structure can realize a broadband absorption above 90% from 15 THz to 27 THz, which is better than other structures in the previous works. Based on the simulated results we can demonstrate that the magnitude of absorption is closely with that of material of the first layer. A remarkable enhance bandwidth can be realized by using the low-conductivity alloy, because the alloy can make more electromagnetic energy dissipated in it. Meanwhile, the overlapping of the high absorption rate in near frequency also contributes to increase the bandwidth. In order to explain the mechanism of high absorption, the surface current distribution and power loss at the resonance frequencies are investigated. Due to the symmetry of this structure, it is insensitive for the polarization. These novel properties can lead to a new possibilities and solution in many applications, such as communication system, polarization-insensitive devices and so on.
- Published
- 2016
- Full Text
- View/download PDF
27. Ultrathin and broadband metamaterial absorber based on new four L structure in infrared and visible region
- Author
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Xiaoxia Zheng, Xinyang Ling, Jingyao Tang, Zhongyin Xiao, and Kaikai Xu
- Subjects
010302 applied physics ,Materials science ,Terahertz radiation ,business.industry ,Infrared ,Physics::Optics ,Photodetector ,Metamaterial ,Optical polarization ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Optics ,0103 physical sciences ,Metamaterial absorber ,Optoelectronics ,Center frequency ,0210 nano-technology ,business ,Absorption (electromagnetic radiation) - Abstract
In this paper, we proposed a broadband and polarization-insensitive metamaterial absorber in infrared and visible region. Our structure composed of three layers, and the remarkable difference is that two materials (InSb and Tin) are used in the top layer simultaneously. The numerical results show that a broadband absorption above 90% from 88.4 to 110.9 THz can be achieved for either transverse electric or magnetic polarization waves due to the effect of using hybrid materials. Moreover, the metamaterial is ultra-thin, having total of 0.3 µm, i.e., λ/10 with respect to the center frequency of the high absorption bands. In addition, the mechanism of high absorption at resonances is discussed based on the surface current and power loss distributions. The power loss distributions between high and low frequency resonant point are distinct. Importantly, the proposed absorber also have a broadband absorption from 639.7 THz to 796.7 THz by adjusting the parameter of the structure and the idea of broadening absorption bandwidth supplies a useful way in THz, infrared, even in optical region. The new “four L” structure absorber has potential application in sensing, energy harvest, integrated photodetectors and so on.
- Published
- 2016
- Full Text
- View/download PDF
28. Drive system reliability analysis of wind turbine based on fuzzy fault tree
- Author
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Jiling Dai, Xiaoxia Zheng, Haohan Ren, Dongdong Li, and Guowang Zhou
- Subjects
Fault tree analysis ,Engineering ,Wind power ,business.industry ,020209 energy ,Fuzzy set ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,02 engineering and technology ,Fault (power engineering) ,Turbine ,Fuzzy logic ,Reliability engineering ,Control theory ,0202 electrical engineering, electronic engineering, information engineering ,Fuzzy number ,020201 artificial intelligence & image processing ,Fault model ,business - Abstract
Wind turbines have been developed fast in the recent years and at the same time have brought some problems because they suffer higher reliability risk being exposed to extreme running environment and subject to constantly variable loadings. A fault tree model has been established from the basic components failure mode of wind turbine drive system. In the view of the mass of existence uncertainty in fault phenomenon, fault condition and fault cause of the actual wind turbine drive system, the fuzzy set theory is introduced into the dynamic fault tree analysis. The triangular fuzzy numbers has been represented the basic event failure parameter of the wind turbine drive system. The fuzzy probability of the occurrence of the top event and the fuzzy probability-significance of the basic event has been obtained by analyzing the fuzzy fault tree of wind turbine drive system and combing the λ cut set theory and interval arithmetic. And the weak link of the system can be found by analyzing the fuzzy probability-significance. The results show that the fuzzy fault tree reliability analysis method can provide a reference for the wind turbine operation and maintenance of the drive system.
- Published
- 2016
- Full Text
- View/download PDF
29. Variational mode decomposition applied to offshore wind turbine rolling bearing fault diagnosis
- Author
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Jing Wang, Xiaoxia Zheng, Guowang Zhou, Haohan Ren, and Dongdong Li
- Subjects
0209 industrial biotechnology ,Engineering ,Bearing (mechanical) ,business.industry ,Mode (statistics) ,020206 networking & telecommunications ,02 engineering and technology ,Structural engineering ,Fault (power engineering) ,Turbine ,law.invention ,Vibration ,Offshore wind power ,020901 industrial engineering & automation ,Modal ,law ,0202 electrical engineering, electronic engineering, information engineering ,Demodulation ,business - Abstract
The incipient fault feature of offshore wind turbine rolling bearing is difficult to extract. A fault diagnosis method for offshore wind turbine rolling bearing based on variational mode decomposition(VMD) method is proposed. Considering the number of mode components has great influence on the decomposition results, the general principles of determination of the mode components number is proposed, which is based on analyzing the VMD decomposition of different modal components number impact on signal frequency characteristics. The number of mode components is determined by the proposed principles and got certain number of mode components . Then the best selected mode component is processed by envelop demodulation algorithm .The fault type of bearing is diagnosed by analyzing the envelop spectrum. The results of the standard rolling bearing fault data analysis shows that the proposed method can diagnose rolling bearing fault accurately. The incipient fault feature of offshore wind turbine vibration data is effectively extracted shows that the proposed method is significance of research and application.
- Published
- 2016
- Full Text
- View/download PDF
30. Wind turbine gearbox fault diagnosis based on EEMD and fractal theory
- Author
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Wenlei Zhou, Dong Dong Li, Xiaolin Ge, Xiaoxia Zheng, and Lin Shunfu
- Subjects
Engineering ,business.industry ,Feature vector ,Pattern recognition ,02 engineering and technology ,White noise ,Fault (power engineering) ,01 natural sciences ,Fractal dimension ,Hilbert–Huang transform ,Time–frequency analysis ,Vibration ,020303 mechanical engineering & transports ,Fractal ,0203 mechanical engineering ,0103 physical sciences ,Electronic engineering ,Artificial intelligence ,business ,010301 acoustics - Abstract
This paper proposes a novel fault diagnosis method for planetary gearbox based on ensemble empirical mode decomposition (EEMD) and fractal theory. EEMD is applied to process the non-stationary vibration signals and get the feature space. The vibration signal is decomposed by EEMD into different frequency bands effectively. The fractal dimension (FD) can extract fault characters from input signal, thus FD can be selected as the characteristic parameters to diagnose planetary gearbox fault. So the fractal dimension of specific intrinsic mode functions (IMF) components is able to reflect the operation condition of planetary gearbox sensitively. The result of experiment indicates that the combination of EEMD and fractal dimension is an effective method for planetary gearbox's fault diagnosis.
- Published
- 2016
- Full Text
- View/download PDF
31. Significance and Creation of Novel Cyclooxygenase-1 (COX-1) Selective Inhibitors
- Author
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Ryosuke Fukai, Xiaoxia Zheng, Kazunori Motoshima, and Hiroki Kakuta
- Subjects
Side effect ,Metabolite ,Analgesic ,Aminopyridines ,Pharmaceutical Science ,Pharmacology ,medicine.disease_cause ,chemistry.chemical_compound ,In vivo ,medicine ,Humans ,Cyclooxygenase Inhibitors ,Benzamide ,Analgesics ,biology ,business.industry ,Stomach ,medicine.anatomical_structure ,chemistry ,Gastric Mucosa ,Drug Design ,Benzamides ,Cyclooxygenase 1 ,biology.protein ,Cyclooxygenase ,Irritation ,business - Abstract
Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used to relieve physical and mental pain, and to improve patients' quality of life. However, stomach irritation is a major side effect. Most NSAIDs inhibit cyclooxygenases (COXs), and inhibition of COX-1 on the stomach mucous membrane is thought to be responsible for the gastric disturb- ance. Consequently, development efforts have focused on COX-2-selective inhibitors, while COX-1-selective inhibitors have been rather neglected. Subsequently, however, it was shown that inhibition of either COX-1 or COX-2 alone does not induce gastric damage. Therefore, we have developed the COX-1-selective inhibitor N-(4-aminophenyl)-4-trifluoromethylbenzamide (TFAP), which shows analgesic activity without causing gastric damage. However, metabolism of TFAP generates a colored metabolite, resulting in red-purple coloration of urine after administration. In addition, the analgesic activity of TFAP is weaker than that of indomethacin. Thus, we designed a series of new COX-1-selective inhibitors, the 5-amino-2-ethoxy-N-(substituted)benzamide (ABEX) series, in order to avoid formation of the colored metabolite by modifying the diaminopyridine skeleton. As a result of structural modification and in vitro and in vivo testing of compounds in the ABEX series, we found a novel COX-1-selective inhibitor, 5-amino-2-ethoxy-N-(3-trifluoromethylphenyl)benzamide (ABEX-3TF), which shows better analgesic activity than indomethacin, and does not cause coloration of urine.
- Published
- 2011
- Full Text
- View/download PDF
32. Generation of optical bottle beams through focusing J0-correlated Schell-model vortex beams
- Author
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Lianzhou Rao, Zongchi Wang, Pu Yei, and Xiaoxia Zheng
- Subjects
Physics ,business.product_category ,business.industry ,Degree of coherence ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Vortex ,Optics ,Bottle ,Physics::Accelerator Physics ,Gravitational singularity ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,business ,Optical vortex ,Topological quantum number ,Beam (structure) ,Coherence (physics) - Abstract
The intensity distribution and the radiation force of the J 0 -correlated Schell-model (JSM) vortex beams focused by a lens are investigated. It is shown that the desired partially coherent vortex bottle beams in the focal region can be obtained by choosing appropriate values of the topological charge n and the correlation length σ . It is shown that such vortex bottle beam ( n ⩾ 1 ) has several advantages over the bottle beam (n = 0). In addition, the degree of coherence is also shown to possess phase singularities.
- Published
- 2008
- Full Text
- View/download PDF
33. Dustfall Heavy Metal Pollution During Winter in North China
- Author
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Xiao-yu Guo, Tong-tong Shu, Xiaoxia Zheng, Fan-tao Chen, Wenji Zhao, Zhaoning Gong, and Qiulin Xiong
- Subjects
Pollution ,China ,Health, Toxicology and Mutagenesis ,media_common.quotation_subject ,North china ,chemistry.chemical_element ,Zinc ,Toxicology ,Air Pollution ,Metals, Heavy ,Soil Pollutants ,Coal ,media_common ,Cadmium ,business.industry ,Heavy metals ,Dust ,General Medicine ,Contamination ,Metal pollution ,chemistry ,Environmental chemistry ,Metallurgy ,Environmental science ,Seasons ,business ,Environmental Pollution ,Copper ,Environmental Monitoring - Abstract
In order to study heavy metal pollution in dustfall during Winter in North China, forty-four dustfall samples were collected in North China Region from November 2013 to March 2014. Then forty trace elements content were measured for each sample by inductively coupled plasma-mass spectrometry. Finally, the contamination characteristics of the main heavy metals were studied through a multi-method analysis, including variability analysis, Pearson correlation analysis and principal component analysis. Results showed that the relative contents of cadmium (Cd), zinc (Zn), copper (Cu), bismuth (Bi), lead (Pb) exceeded the standards stipulated in Chinese soil elements background values by amazing 4.9 times. In this study, conclusions were drawn that dustfall heavy metal pollution in the region was mainly caused by transport pollution, metallurgy industrial pollution, coal pollution and steel industrial pollution.
- Published
- 2015
34. Algorithm for residential appliance identification based on continuous quadratic 0–1 programming
- Author
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Qingqiang Liu, Xiaoxia Zheng, Shunfu Lin, and Dongdong Li
- Subjects
Engineering ,Quadratic equation ,Residential energy ,business.industry ,Power consumption ,Nonintrusive load monitoring ,Real-time computing ,Control engineering ,business ,Scheduling (computing) - Abstract
The decomposed information of power consumption of household appliances is meaningful for scheduling the appliances and the reduction in home energy use. This paper presents a novel nonintrusive load identification method based on continuous quadratic 0-1 programming. Extensive lab tests have demonstrated that the proposed technique can provide adequate load identification accuracy for residential energy monitoring and is suitable to be used in a nonintrusive load monitoring (NILM) systems in residential and commercial buildings.
- Published
- 2014
- Full Text
- View/download PDF
35. Ant Colony Optimization Algorithm Based on Immune Strategy
- Author
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Yang Fu and Xiaoxia Zheng
- Subjects
Mathematical optimization ,Computer science ,business.industry ,Artificial immune system ,Ant colony optimization algorithms ,MathematicsofComputing_NUMERICALANALYSIS ,Ant colony ,ComputingMethodologies_ARTIFICIALINTELLIGENCE ,Travelling salesman problem ,ANT ,TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY ,Artificial Ants ,Artificial intelligence ,business - Abstract
Ant Colony Optimization (ACO) is inspired by the ability of ant colonies to find shortest paths between their nest and a food source. The paper proposed a modified ACO based on artificial immune strategy. The mechanism of the vaccination, antibody diversity and clonal deletion theory in artificial immune system are introduced to improve the ways of artificial ants search solution space and the elite ant's capability. Also it can solve the conflict between the diversity of the solutions searched by ant colony and the convergence speed. The simulation results by examples of traveling salesman problem(TSP) show that adding immune strategy to ants group can find better solution in shorter time than ACO.
- Published
- 2011
- Full Text
- View/download PDF
36. Comparison between Typical Discriminative Learning Model and Generative Model in Chinese Short Messages Service Spam Filtering
- Author
-
Hongwei Yu, Chao Liu, Chengzhe Huang, Xiaoxia Zheng, and Yu Zou
- Subjects
business.industry ,Computer science ,Bayesian probability ,Logistic regression ,Bayesian inference ,computer.software_genre ,Machine learning ,Naive Bayes classifier ,Generative model ,ComputingMethodologies_PATTERNRECOGNITION ,n-gram ,Discriminative model ,Bag-of-words model ,Artificial intelligence ,Data mining ,business ,computer - Abstract
We used the experience of spam filtering on account of Chinese short messages service spam filtering and compared the performances of typical discriminative learning model and generative model, namely naive bayesian model and logistic regression model. Overall, in Chinese short messages service spam filtering, the performance of naive bayesian model is better than logistic regression model using 1-ROCA as evaluating indicator while the final performance of logistic regression model is better than naive bayesian model with the increase in amount of short messages, which is deferent from spam filtering as shown in this experimental results.
- Published
- 2010
- Full Text
- View/download PDF
37. Access control through self-existent mechanism
- Author
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Xiaoxia Zheng, Fangyong Hou, Nong Xiao, and Hongjun He
- Subjects
Structure (mathematical logic) ,business.industry ,Computer science ,Control (management) ,Access control ,Computer security ,computer.software_genre ,law.invention ,Microprocessor ,Software ,Trojan ,law ,business ,Advice (complexity) ,computer ,Mechanism (sociology) ,Computer network - Abstract
This paper proposes a security paradigm named self-existent mechanism of access control. The most distinct character is that it runs absolutely independent from program executing environment, even without cooperation of OS. That is to say, it has a unique structure to assure that computing is controlled under a secure mechanism that cannot be penetrated by software like virus, Trojan and other malicious programs. This paper explains its principle, and describes how to accomplish such control over general computers. Also, this paper gives advice to the design of microprocessor to make this control mechanism to work better.
- Published
- 2010
- Full Text
- View/download PDF
38. Electric load forecasting using Bayesian Least Squares Support Vector Machine
- Author
-
Xiaoxia Zheng
- Subjects
Structured support vector machine ,Artificial neural network ,Computer science ,business.industry ,Bayesian probability ,Machine learning ,computer.software_genre ,Regularization (mathematics) ,Relevance vector machine ,Support vector machine ,Kernel (linear algebra) ,Statistical learning theory ,Least squares support vector machine ,Artificial intelligence ,Data mining ,business ,computer ,Test data - Abstract
Electric load forecasting has received increasing attention over the years by academic and industrial researchers due to its major role for the effective and economic operation of power utilities. Least Support Vector Machine (LS SVM) is a new learning machine based on the statistical learning theory. A modelling approach based on least squares support vector machine (LS SVM) within the Bayesian evidence framework for short-term load forecasting is proposed. Under the evidence framework, the regularization and kernel parameters can be adjusted automatically, which can achieve a fine tradeoff between the minimum error and model's complexities. The proposed approach is tested using actual power load data sets. Experimental results show that the proposed approach has better generalization performance and yields lower prediction error compared with LS SVM using the same test data set.
- Published
- 2010
- Full Text
- View/download PDF
39. Prediction of impact damage on stitched sandwich composite panels
- Author
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Xiaoxia Zheng, Linhu Gou, Jianfeng Zhang, and Xitao Zheng
- Subjects
Image stitching ,Core (optical fiber) ,Face sheet ,Materials science ,Computer simulation ,business.industry ,Delamination ,Composite number ,Impact energy ,Structural engineering ,Composite material ,business ,Finite element method - Abstract
Based on the analysis of experiments, the damage of composite stitched foam-core sandwich structure under low-velocity impact has been studied in this paper. A numerical simulation is performed to predict the effects of stitching on the low-velocity impact response of stitched sandwich composite panels. The results of numerical simulation show that the damage areas of upper face sheet are greater than the lower one for both unstitched and stitched sandwich, however, the main patterns of damage are different. For the unstitched structure, the upper face sheet's damage is the main pattern of damage, whereas the crushing damage is the stitched one's main damage. The finite element results have corresponded well with the experimental results, which prove the correctness of the finite element model. The results indicate that stitching does not increase the load at which delamination begins to propagate, but greatly reduces the extent of delamination growth at the end of the impact event. Then, the damage areas' change has been taken into consideration as some factors change, those various factors include the impact energy, the thickness of upper panel, the thickness of foam core and the stitched density (stitched row spacing×needle spacing, suture thickness). And also it presents some related theoretical analysis.
- Published
- 2009
- Full Text
- View/download PDF
40. Nonlinear system identification based on LSSVM within the evidence framework
- Author
-
Xiaoxia Zheng
- Subjects
Nonlinear system identification ,business.industry ,Machine learning ,computer.software_genre ,Regularization (mathematics) ,Relevance vector machine ,Support vector machine ,symbols.namesake ,Statistical learning theory ,Kernel (statistics) ,Least squares support vector machine ,symbols ,Artificial intelligence ,business ,computer ,Gaussian process ,Mathematics - Abstract
Support vector machine (SVM) is a new learning machine based on the statistical learning theory. A regression algorithm based on least squares support vector machine (LS SVM) within the Bayesian evidence framework is discussed. Also the Gauss kernel parameter selecting method is proposed. Under the evidence framework, the regularization and kernel parameters can be adjusted automatically, which can achieve a fine tradeoff between the minimum error and modelpsilas complexities. This method is applied to nonlinear system identification and the simulation results show the effectiveness and superiority of the proposed approach. It provides a new way for modeling and identification of complicated industrial processes.
- Published
- 2008
- Full Text
- View/download PDF
41. Fault diagnosis of PTA oxidation process based on decision tree and ant colony optimization
- Author
-
Xiaoxia Zheng and Feng Qian
- Subjects
Engineering ,Incremental decision tree ,business.industry ,Decision tree learning ,Ant colony optimization algorithms ,ID3 algorithm ,Decision tree ,Machine learning ,computer.software_genre ,Rough set ,Artificial intelligence ,Data mining ,business ,Decision table ,computer ,Decision tree model - Abstract
Data mining technique can extract desired knowledge from existing databases and ease knowledge acquisition bottleneck of fault diagnosis. A new knowledge acquisition method combined of decision tree and rough set theory is thus proposed for fault diagnosis in this paper. Based on the reduction by rough set theory, decision tree extract diagnostic knowledge from the reduced decision tables in the form of symbolic trees. Trend correlation degree, as the heuristic knowledge, is proposed to evaluate the significance of condition attributes for the construction of decision tree model. Also a modified ant colony algorithm is introduced to determine the optimal fault test sequence of the decision tree model. The proposed method is applied to the fault diagnosis of purified terephthalic acid (PTA) oxidation reactor, which is the key unit in AMOCO PTA production technique. The results show the method is satisfactory and suitable for industrial application.
- Published
- 2008
- Full Text
- View/download PDF
42. Effect of the oral absorption of benzenesulfonanilide-type cyclooxygenase-1 inhibitors on analgesic action and gastric ulcer formation
- Author
-
Hiroki Kakuta, Akihiro Tai, Shun Harada, Kenji Sasaki, Hiroyuki Oda, Xiaoxia Zheng, and Yukio Sugimoto
- Subjects
Formalin Test ,Analgesic ,Pharmaceutical Science ,Administration, Oral ,Absorption (skin) ,Pharmacology ,Inhibitory postsynaptic potential ,Rats, Sprague-Dawley ,Mice ,In vivo ,medicine ,Animals ,Cyclooxygenase Inhibitors ,Stomach Ulcer ,Chromatography, High Pressure Liquid ,Analgesics ,Mice, Inbred ICR ,Sulfonamides ,biology ,business.industry ,Sulfonamide (medicine) ,In vitro ,Rats ,biology.protein ,Cyclooxygenase ,business ,medicine.drug - Abstract
A benzensulfonanilide-type cyclooxygenase-1 (COX-1)-selective inhibitor, ZXX2-77: 4-amino-4'-chloro-N-methylbenzenesulfonanilide (4a), has been reported as a novel analgesic that does not cause gastric damage. This compound has a weak analgesic effect but has potent in vitro COX-1 inhibitory activity. Since the reason for the weak analgesic effect in vivo was thought to be the low rate of oral absorption, the blood concentration of ZXX2-77 (4a) was measured in rats. It was found that the C(max) value (1.2 microM) of ZXX2-77 (4a) at a dose of 30 mg/kg did not reach the COX-1 IC(50) value (3.2 microM). On the other hand, ZXX2-79 (4b) (SO(2)NH derivative of ZXX2-77 (4a); 4-amino-4'-chlorobenzenesulfonanilide), which shows less potent COX inhibitory activities (COX-1 IC(50) = 12 microM, COX-2 IC(50) = 150 microM) than those of ZXX2-77 (4a) in vitro, was found to be more absorbable (C(max) = 16 microM at a dose of 30 mg/kg in rats) than ZXX2-77 (4a). Furthermore, ZXX2-79 (4b) not only showed a potent analgesic effect in a formalin test but also caused little gastric damage. These findings indicate that demethylated sulfonamide compounds are more easily absorbed than are N-methylated sulfonamide compounds and suggest that COX-1-selective inhibitors will be useful as analgesics that do not cause gastric damage.
- Published
- 2008
43. An Expert System for Real-time Fault Diagnosis and Its Application in PTA Process
- Author
-
Xiaoxia Zheng, Zhenlei Wang, and Feng Qian
- Subjects
Engineering ,Knowledge representation and reasoning ,business.industry ,Interface (computing) ,computer.software_genre ,Machine learning ,Fault (power engineering) ,Automation ,Expert system ,Knowledge base ,Data pre-processing ,Data mining ,Artificial intelligence ,Inference engine ,business ,computer - Abstract
Increasing complexity and automation of the chemical process industries requires more reliable and efficient real-time fault diagnosis systems. Here, a real-time expert system based on wavelet transform and fuzzy ART neural network is introduced for fault diagnosis, providing fault prediction to help operators before abnormal situations occur. Data preprocessing, knowledge base structure, representation of knowledge, generalized inference engine and graphic user interface are technically considered. Industrial applications in Pure Terephthalic Acid (PTA) process indicate that the real-time expert system diagnoses abnormal events efficiently and promptly and it has many specialties such as friendly interface, easy to train and maintain and also reliable under changing process conditions.
- Published
- 2006
- Full Text
- View/download PDF
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