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一类具有毒素的非均匀chemostat模型正解的存在性和稳定性

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中山大学学报（自然科学版） 2021年第3期60卷 167-173页

作者：李海侠宝鸡文理学院数学与信息科学学院陕西宝鸡721013

研究了一类具有毒素的非均匀chemostat食物链模型。利用最大值原理和上下解方法给出了正解的先验估计。接着运用简单特征值的分歧理论探讨了正解的全局分支,得到了正解存在的充要条件。最后采用线性算子的扰动理论和分歧解的稳定性理论... 详细信息

研究了一类具有毒素的非均匀chemostat食物链模型。利用最大值原理和上下解方法给出了正解的先验估计。接着运用简单特征值的分歧理论探讨了正解的全局分支,得到了正解存在的充要条件。最后采用线性算子的扰动理论和分歧解的稳定性理论讨论了正分歧解的稳定性。研究结果表明在毒素的影响和适当条件下物种能够共存且正解稳定。

关键词：非均匀chemostat模型分歧理论全局分支稳定性

H2S protects against diabetes-accelerated atherosclerosis by preventing the activation of NLRP3 inflammasome

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The Journal of Biomedical Research 2020年第2期34卷 94-102页

作者： Qiao zheng Lihong Pan Yong Ji Key Laboratory of Cardiovascular and Cerebrovascular Medicine Key Laboratory of Targeted Intervention of Cardiovascular DiseaseCollaborative Innovation Center for Cardiovascular Disease Translational MedicineNanjing Medical UniversityNanjingJiangsu 211166China

Hydrogen sulfide(H2S) is an important messenger for its strong anti-inflammatory effects, which may be involved in multiple cardiovascular diseases. In our previous study, we revealed that H2S attenuated diabetesaccelerated atherosclerosis through suppressing oxidative stress. Here we report that GYY4137, a H2S donor,reduced the plaque formation of aortic roots and the levels of both intercellular cell adhesion molecule 1(ICAM1)and vascular cell adhesion molecule 1(VCAM1) in diabetes-accelerated atherosclerotic cells and mouse *** inflammatory factors of TNF-α, IL-1β, IL-6, and MCP1 were also significantly reduced by ***, GYY4137 suppressed the activation of pyrin domain containing protein 3(NLRP3) inflammasome in diabetes-accelerated atherosclerosis conditions. Upon knockdown of NLRP3, the increase of ICAM1 and VCAM1 caused by high glucose and ox LDL could be reversed, indicating that H2S protected the endothelium by inhibiting the activity of NLRP3 inflammasome. In conclusion, our study indicates that GYY4137 effectively protects against the development of diabetes-accelerated atherosclerosis by inhibiting inflammasome activation.

关键词： H2S NLRP3 inflammation diabetes-accelerated atherosclerosis

A Hybrid Features Based Detection Method for Inshore Ship Targets in SAR Imagery

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Journal of Geodesy and Geoinformation Science 2023年第1期6卷 95-107页

作者： Tong zheng Peng LEI Jun WANG School of Artificial Intelligence Beijing Technology and Business UniversityBeijing 100031China School of Electronic and Information Engineering Beihang UniversityBeijing 100083China

Convolutional Neural Networks(CNNs)have recently attracted much attention in the ship detection from Synthetic Aperture Radar(SAR)***,compared with optical images,SAR ones are hard to ***,due to the high similarity between the man-made targets near shore and inshore ships,the classical methods are unable to achieve effective detection of inshore *** mitigate the influence of onshore ship-like objects,this paper proposes an inshore ship detection method in SAR images by using hybrid ***,the sea-land segmentation is applied in the pre-processing to exclude obvious land regions from SAR ***,a CNN model is designed to extract deep features for identifying potential ship targets in both inshore and offshore *** this basis,the high-energy point number of amplitude spectrum is further introduced as an important and delicate feature to suppress false alarms ***,to verify the effectiveness of the proposed method,numerical and comparative studies are carried out in experiments on Sentinel-1 SAR images.

关键词： Convolutional Neural Network(CNN) Synthetic Aperture Radar(SAR) inshore ship detection hybrid features high-energy point number amplitude spectrum

Current treatment of chronic hepatitis C in China: Dilemma and potential problems

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World Journal of Gastroenterology 2016年第19期22卷 4615-4618页

作者： Qun-Ying Han zheng-Wen Liu Department of Infectious Diseases First Affiliated Hospital of Xi’an Jiaotong University

Major advances have been made in the treatment of chronic hepatitis C virus(HCV) infection with the advent of direct-acting antiviral agents(DAAs). China has the most cases of HCV infection worldwide, but none of the DAAs has been approved in China's Mainland so far, and interferon(IFN)-α-based treatment remains the standard of care. HCV patients without response or with contraindications to IFN-based therapy have no alternative options. However, many patients buy DAAs, especially the generic forms of sofosbuvir, from other countries or areas. Under these circumstances, the use of these drugs may cause many predictable and unpredictable problems in ethics, law and medical practice. Given the obstacles of legal accessibility to DAAs and the potential problems of obtaining and using DAAs in China, the early launching of the DAAs in China or the legalization of buying drugs from areas outside China and using these drugs in China is an urgent issue and needs to be dealt with as soon as possible, in the interest of the patients.

关键词： Hepatitis C virus infection Treatment Direct-acting antiviral agent Generics China

Design of Tapered Novel AMC Chessboard Reflector for Broadband RCS Reduction

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Journal of Beijing Institute of Technology 2019年第4期28卷 739-743页

作者： Wenbo zheng Wei Song Xinqing Sheng Center for Electromagnetic Simulation School of Information and ElectronicsBeijing Institute of TechnologyBeijing 100081China

An artificial magnetic conductor(AMC)chessboard reflector is designed which shows low backscattered radar cross sections(RCS)in a broad frequency band in this *** by the phase cancellation principle,a conventional chessboard low RCS metasurface can be formed by polarization-dependent mushroom-shaped *** new features are added to this design based on the conventional chessboard ***,the long edge of the metallic patch on the AMC element is concave to obtain a broader ***,the width of the patch in each AMC block is tapered in one direction to further extend the operating bandwidth for RCS *** backscattered RCS of the tapered AMC reflector is numerically investigated and compared with a non-tapered *** is found that by introducing the above features,an RCS reduction greater than *** can be obtained by the reflectors with relative bandwidth of 46%in the X-band.

关键词： artificial magnetic conductor(AMC) radar cross section(RCS)reduction reflector

Study on the viscoelastic behavior of SEEPS block copolymer based on a modified BSW model

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Chinese Science Bulletin 2005年第19期50卷 2171-2175页

作者： WANG Wanjie zheng Qiang YU Qiuming Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027 China State Key Laboratory of Fluid Power Control and Transmission Zhejiang University Hangzhou 310027 China

Studies on the viscoelastic behavior of styrene- [ethylene-(ethylene-propylene)]-styrene block copolymer (SEEPS) were carried out, and some characteristic viscoelas-tic parameters were calculated. The longest relaxation time τmax was obtained through simulating the relaxation spec-trum on the basis of a modified Baumgaertel-Schausberger- Winter (mBSW) model. The results revealed that there exists a “second plateau” in the low frequency region of the master curves. The reason for this phenomenon is attributed to the entanglement of macromolecular chains. It is suggested that the hard blocks, polystyrene, act as entanglement points, resulting in a topology restraint to the movement of macro-molecular chains. Meanwhile, it is found that the horizontal shift factors (aT) vs temperature in the master curve could be fitted to the Williams-Landel-Ferry (WLF) equation and Ar-rhenius equation respectively and the flow activation energy (Ea) is 127.88 kJ/mol. In addition, the plateau modulus (GN0) and entanglement molecule weight (Me) were calculated.

关键词：苯乙烯共聚物时间温度重合法则黏弹性参数时间光谱频率曲线

Strategy of preparing SmCo based films with high coercivity and remanence ratio achieved by temperature and chemical optimization

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Journal of Rare Earths 2024年第7期42卷 1289-1297,I0004页

作者： Yansong Gong Zhaoguo Qiu Sizhe Liang Xinrui zheng Hongxia Meng Zhigang zheng Deyang Chen Shengfu Yuan Weixing Xia Dechang Zeng J.P.Liu School of Materials Science and Engineering South China University of TechnologyGuangzhou510640China Zhongshan R&D Center for Materials Surface and Thin Films Technology of the South China University of Technology Gent Materials Surface Technology(Guangdong)Co.Ltd.Zhongshan528437China Institute for Advanced Materials South China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou510006China Yangjiang Branch Guangdong Laboratory Materials Science and Technology Yangjiang Advanced Alloys LaboratoryYangjiang529500China Laboratory of Rare-Earth Magnetic Functional Materials Ningbo Institute of Material Technology and EngineeringChinese Academy of SciencesNingbo315201China Department of Physics University of Texas at ArlingtonArlingtonTX76019USA

SmCo based films with excellent intrinsic magnetic properties have promising applications in micro-electro-mechanical system(MEMS).However,due to the complexity of phase composition and uncontrollable crystallization degree of SmCo hard magnetic phase in the film,both the coercivity(Hc)and remanence(Mr)of films are difficult to enhance *** this paper,SmCo based films were deposited with a Cr underlayer and capping layer on single crystal Si substrates via magnetron sputtering *** effects of annealing parameters and Sm/Co atomic ratio on the phase structure and coercivity of films are *** adjusting the Sm/Co atomic ratio from 1:5 to 1:4,Co soft magnetic phase disappears and the single phase SmCo5 is obtained,leading to the increase of coercivity of the films from 30 to 34 *** influence of deposition temperature and Cu doping on magnetic properties of SmCo based films was *** the deposition temperature increases from room temperature to 250℃,the coercivity will further increase from 34 to 51 ***,a severe kink is observed in the demagnetization curves due to the poor exchanged *** analysis of transmission electron microscopy(TEM)confirms that the average size of non-hard magnetic amorphous phase exceeds the effective exchanged coupling length of SmCo5,which contributes to the decoupling and low remanence ***,doping Cu and applying a post-annealing process can significantly improve the crystallization degree of the *** the coercivity and the remanence ratio of the demagnetization curves are greatly *** propose a plausible strategy to prepare the SmCo based films with high coercivity and remanence ratio by temperature and chemical optimization,which can be utilized in high performed MEMS devices.

关键词： Rare earths SmCo based films Phase composition Crystallization conditions Coercivity Remanence ratio

Image Semantic Segmentation Approach for Studying Human Behavior on Image Data

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Wuhan University Journal of Natural Sciences 2024年第2期29卷 145-153页

作者： zheng Zhan CHEN Da HUANG Yanrong School of Communication Wuhan Textile UniversityWuhan 430073HubeiChina Walnut Street(Shanghai)Information Technology Co. Ltd.Shanghai 200051China College of Economics&Management Zhejiang University of Water Resources and Electric PowerHangzhou 310018ZhejiangChina Research Center for Digital Economy and Sustainable Development of Water Resources Hangzhou 310018ZhejiangChina

Image semantic segmentation is an essential technique for studying human behavior through image *** paper proposes an image semantic segmentation method for human behavior ***,an end-to-end convolutional neural network architecture is proposed,which consists of a depth-separable jump-connected fully convolutional network and a conditional random field network;then jump-connected convolution is used to classify each pixel in the image,and an image semantic segmentation method based on convolu-tional neural network is proposed;and then a conditional random field network is used to improve the effect of image segmentation of hu-man behavior and a linear modeling and nonlinear modeling method based on the semantic segmentation of conditional random field im-age is ***,using the proposed image segmentation network,the input entrepreneurial image data is semantically segmented to obtain the contour features of the person;and the segmentation of the images in the medical *** experimental results show that the image semantic segmentation method is *** is a new way to use image data to study human behavior and can be extended to other research areas.

关键词： human behavior research image semantic segmentation hop-connected full convolution network conditional random field network deep learning

Comparative Study on the Legal Regulation of a Cross-Border Flow of Personal Data and Its Inspiration to China

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Frontiers of Law in China-Selected Publications from Chinese Universities 2020年第3期15卷 280-312页

作者： zheng Weiwei School of Law Jilin UniversityChangchunChina School of Law Renmin University of China Law and Technology Institute Renmin University of China Center for Cross-Border Data Transfer and Online Dispute Resolution Renmin University of ChinaBeijing 100872China

In the context of today's big data and cloud computing,the global flow of data has become a powerful driver for international economic and investment *** EU and the *** created two different paths for the legal regulation of the cross-border flow of personal data due to their respective historical traditions and realistic *** requirements for data protection have shown significant *** EU advocates localization of data and firmly restricts cross-border flow of personal *** *** to protect personal data through industry self-regulation and government law *** the same time,these two paths also merge and supplement with each *** on this,China needs to learn from the legal regulatory paths of the EU and the US,respectively,to establish a legal idea that places equal emphasis on personal data protection and the development of the information *** terms of domestic law,the Cybersecurity Law of the People's Republic of China needs to be improved and supplemented by relevant supporting legislation to improve the operability of the law;the industry self-discipline guidelines should be established;and various types of cross-border data need to be classified and *** terms of international law,it is necessary to participate in international cooperation based on the priority of data sovereignty and promote the signing of bilateral,multilateral agreements,and international treaties on the cross-border flow of personal data.

关键词： cross-border flow personal data legal regulation data sovereignty industry self-regulation key information infrastructure