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Feedback analysis and design of inductive power links driven by Class-E amplifiers with variable coupling coefficients

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Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第8期11卷 629-636页

作者： tian-liang YANG Chun-yu ZHAO da-yue CHEN Institute of Intelligent Mechatronics Research School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University Shanghai 200240 China

The efficiency of inductive power links driven by Class-E amplifiers may deteriorate due to variation in the coupling coefficient when the relative position of the radio frequency (RF) coils *** solve this problem,a new design methodology of power links is presented in this *** aim of the new design is to use the feedback signal,which is a phase difference between the driving signal and the output current of the Class-E amplifier,to adjust the duty cycle and angular frequency of the driving signal to maintain the optimum state of the inductive power link,and to adjust the supply voltage to keep the output power constant when the coupling coefficient of the RF coils *** parameter adjustments with respect to the coupling coefficient and the feedback signal are derived from the design equation of the inductive power *** validate the feedback control rules,a prototype of the inductive power link was constructed,and its performance validated with the coupling coefficient set at 0.2 and a duty cycle of *** experimental results showed that,by adjusting the duty cycle,the angular frequency,and the supply voltage,the power link can be kept in optimal operation with a constant output power when the coupling coefficient changes from 0.2 to 0.1 to 0.25.

关键词： Inductive power link Closed-loop Class-E amplifier High efficient Variable coupling coefficient

High glucose augments stress-induced apoptosis in endothelial cells.

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Journal of Geriatric Cardiology 2009年第2期6卷 102-107页

作者： Wenwen zhong Yang Liu Hui tian Department of Geriatric Endocrinology Chinese PLA General Hospital Beijing 100853 China

Hyperglycemia has been identified as one of the important factors involved in the microvascular complications of diabetes, and has been related to increased cardiovascular mortality. Endothelial damage and dysfunction result from diabetes; therefore, the aim of this study was to determine the response of endothelial cells to stressful stimuli, modelled in normal and high glucose concentrations in vitro. EAhy 926 endothelial ceils were cultured in 5 mmol/L or 30 mmol/L glucose conditions for a 24 hour period and oxidative stress was induced by exposure to hydrogen peroxide （HzO2） or tumour necrosis factor- α （TNF- α ）, following which the protective effect of the glucocorticoid dexamethasone was assessed. Apoptosis, necrosis and cell viability were determined using an ELISA for DNA fragmentation, an enzymatic lactate dehydrogenase assay and an MTT assay, respectively. High glucose significantly increased the susceptibility of EAhy 926 cells to apoptosis in the presence of 500 gmol/L H2O2 , above that induced in normal glucose （P〈0.02）. A reduction of H2O2- and TNF- a -induced apoptosis occurred in both high and low glucose after treatment with dexamethasone （P〈0.05）. Conclusion high glucose is effective in significantly augmenting stress caused by H2O2, but not in causing stress alone. These findings suggest a mechanism by which short term hyperglycemia may facilitate and augment endothelial damage.

关键词： Hyperglycemia endothelial cells oxidative stress glucocorticoid

Transfection of bone marrow mesenchymal stem cells using green fluorescence protein labeled hVEGF165 recombinant plasmid mediated by liposome

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Asian Pacific Journal of Tropical Medicine 2013年第9期6卷 739-742页

作者： Tao Wang tian-An Liao Shao-Bo zhong Dental Medical Center People's Hospital of Hainan Province

Objective:To study the role of bone marrow mesenchymal stem cells(BMSCs)in construction of vascularized engineered ***:hVEGF165 was amplified via RT-PCR before recombinant with pShuttle-green fluorescence protein;green fluorescent protein(GFP)-*** the recombinant shuttle plasmid was transfected into BMSCs with Lipofectamine^(TM)2000 for packaging and ***165 mRNA expression in BMSCs cells was ***:The sequence of hVEGFI65 in pShutlle-GFP-hVFGF165 plasmid was confirimed by double-enzyme cleavage method and ***165 was highly expressed in ***:The GFP/hVECF165 recombinant plasmid vector was constructed successfully and expressed effectively in host cells,which may be helpful for discussing the possibility of the application of VEGF165-BMSCs in tissue engineering and ischemic disease cure.

关键词： Vascular endothelial growth factor Green fluorescent protein Bone marrow mesenchymal stem cells Plasmid

Assembly and features of secondary metabolite biosynthetic gene clusters in Streptomyces ansochromogenes

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Science China(Life Sciences) 2013年第7期56卷 609-618页

作者： zhong XingYu tian YuQing NIU GuoQing TAN HuaRong State Key Laboratory of Microbial Resources Institute of Microbiology Chinese Academy of Sciences University of Chinese Academy of Sciences

A draft genome sequence of Streptomyces ansochromogenes 7100 was generated using 454 sequencing technology. In combination with local BLAST searches and gap filling techniques, a comprehensive antiSMASH-based method was adopted to assemble the secondary metabolite biosynthetic gene clusters in the draft genome of S. ansochromogenes. A total of at least 35 putative gene clusters were identified and assembled. Transcriptional analysis showed that 20 of the 35 gene clusters were expressed in either or all of the three different media tested, whereas the other 15 gene clusters were silent in all three different media. This study provides a comprehensive method to identify and assemble secondary metabolite biosynthetic gene clusters in draft genomes of Streptomyces, and will significantly promote functional studies of these secondary metabolite biosynthetic gene clusters.

关键词： secondary metabolite gene cluster assemble features draft genome

Cable-like Au@SiO2 Janus composite nanorods

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Chinese Chemical Letters 2018年第3期29卷 353-356页

作者： tian-Hao Han Fu-Xin Liang Zhen-zhong Yang State Key Laboratory of Polymer Physics and Chemistry Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100190 China

Cable-like Au@SiO2 Janus composite nanorods with PS and PEG grafting on both ends respectively are fabricated by skiving in combination of a post favorable modification. The cable-like Au@SiO2 composite nanofibers are synthesized in the channel of porous anodic aluminium oxide （AAO） membrane. After skiving, the corresponding composite nanorods are obtained. Following, PEG-SH and PS-SH are conjugated onto the two ends of the nanorods by a selective partial modification, respectively. Length and diameter of the Au@SiO2 Janus composite nanorods can be tuned controllably. It can be extended to fabricate a variety of different Janus nanorods with different compositions and microstructures.

关键词： AAO membrane Janus Nanomds Skiving Selective modification

Enantioselective[2+2]cycloaddition of 1,2-dihydroquinolines with 3-olefinic oxindoles via Brønsted acid catalysis

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Organic Chemistry Frontiers 2022年第6期9卷 1621-1627页

作者： Biao Wang Xiao Yan Han zhong Qin Ouyang Xu tian Key Laboratory of Molecular Target&Clinical Pharmacology and the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences&the Fifth Affiliated HospitalGuangzhou Medical UniversityXinzaoPanyu DistrictGuangzhou511436China College of Pharmacy Third Military Medical UniversityChongqing400038China

Mutually complementary regiodivergent Brønsted acid-catalyzed atom-economical[2+2]cycloadditionand ene reactions of 1,2-dihydroquinolines with 3-olefinic oxindoles are *** the presence of achiral phosphoramide catalyst,the[2+2]cycloaddition affords products with four contiguous stereocenters in good to excellent yields(up to 95%)and with high stereoselectivities(up to>99%ee,>20:1 dr).Conversely,with a stronger Brønsted acid,the trifluoromethanesulfonic acid catalyst leads to ene reactionproducts in high yields(up to 77%).Furthermore,the mechanisms of the reactions are discussed based oncontrol experiments and DFT calculations.

关键词： catalyst cycloaddition indole

Novel approach for active vibration control of a flexible missile

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Defence Technology（防务技术） 2020年第4期16卷 956-967页

作者： Cheng-long Pan Ji-li Rong tian-fu Xu da-lin Xiang School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Norinco Group Aviation Ammunition Research Institute Harbin 150030China Beijing Institute of Astronautical Systems Engineering Beijing 100076China

This paper investigates the feasibility of using an active dynamic vibration absorber(ADVA) for active vibration control of a flexible missile system through *** on the principles of a dynamic vibration absorber(DVA),a ring-type ADVA is first designed to attenuate the elastic vibration of the flexible missile,and the design of the active controller adopts the proportional-integral-derivative(PID)control *** motion equations of a flexible missile with an ADVA,which is subjected to follower thrust at its aft end,are derived using the Lagrangian *** the minimum of the root mean square(RMS) of the lateral displacement response of the center of mass as the objective function,a genetic algorithm(GA) is used to optimize the parameter of the DVA and PID *** numerical calculations show that the ADVA and DVA are effective in suppressing the vibration and provide approximately 41.2% and 17.6% improvement,respectively,compa red with the case of no DVA,The ADVA has better performance than the DVA,When the missile is subjected to follower thrust,the effect of vibration reduction is more effective than the case without follower *** is feasible to reduce vibration and improve the stability of flexible missiles by means of the ADVA.

关键词： Flexible missile PID controller Active dynamic vibration absorber Genetic algorithms

Agro-climatic adaptation of cropping systems under climate change in Shanghai

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Frontiers of Earth Science 2015年第3期9卷 487-496页

作者： Zhuoran LIANG Tingting GU Zhan tian Honglin zhong Yuqi LIANG Hangzhou Meteorological Service Hangzhou 310051 China Shanghai Climate Center Shanghai Meteorological Service Shanghai 200030 China Zhejiang Meteorological Service Center Hangzhou 310017 China Department of Geographical Sciences University of Maryland College Park MD 20742 USA Department of Physics and Technology Nanjing Normal University Nanjing 210023 China

Climate change affects the heat and water resources required by agriculture, thus shifting cropping rotation and intensity. Shanghai is located in the Taihu Lake basin, a transition zone for various cropping systems. In the basin, moderate climate changes can cause major shifts in cropping intensity and rotation. In the present study, we integrated observational climate data, one regional climate model, land use maps, and agricultural statistics to analyze the relationship between heat resources and multi-cropping potential in Shanghai. The results of agro-climatic assessment showed that climate change over the past 50 years has significantly enhanced regional agro- climatic resources, rendering a shift from double cropping to triple cropping possible. However, a downward trend is evident in the actual multi-cropping index, caused principally by the increasing costs of farming and limitations in the supply of labor. We argue that improving the utilization rate of the enhanced agro-climatic resources is possible by introducing new combinations of cultivars, adopting more laborsaving technologies, and providing incentives to farmers.

关键词： climate change cropping systems multicropping index double rice Cold Dew wind

System Architecture and Key Technologies of Network Security Situation Awareness System YHSAS

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Computers, Materials & Continua 2019年第4期59卷 167-180页

作者： Weihong Han Zhihong tian Zizhong Huang Lin zhong Yan Jia Cyberspace Institute of Advanced Technology Guangzhou UniversityGuangzhou510006China Computer School National University of Defense TechnologyChangsha410073China Electrical and Computer Engineering Rice University77051USA

Network Security Situation Awareness System YHSAS acquires,understands and displays the security factors which cause changes of network situation,and predicts the future development trend of these security *** is developed for national backbone network,large network operators,large enterprises and other large-scale *** paper describes its architecture and key technologies:Network Security Oriented Total Factor Information Collection and High-Dimensional Vector Space Analysis,Knowledge Representation and Management of Super Large-Scale Network Security,Multi-Level,Multi-Granularity and Multi-Dimensional Network Security Index Construction Method,Multi-Mode and Multi-Granularity Network Security Situation Prediction Technology,and so *** performance tests show that YHSAS has high real-time performance and accuracy in security situation analysis and trend *** system meets the demands of analysis and prediction for large-scale network security situation.

关键词： Network security situation awareness network security situation analysis and prediction network security index association analysis multi-dimensional analysis