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Economic and Political Studies 2019年第4期7卷 480-505页

作者： Rong Xu Jialu chang Conggang Li Wenlan Wang School of Finance&china Financial Policy Research Center Renmin University of ChinaBeijingP.R.China

The 2015 chinese stock market crisis triggered liquidation because of equity pledge so that the leverage effect of the small probability event with severe results got intensive attention from *** is found that the effects of equity pledge on stock price crash risk reversed significantly before and after the 2015 stock market *** the mechanism analysis,we further find that the equity pledge influenced the stock price crash risk by longer suspension and greater price *** shareholding ratio of institutional investors and information environment also had a significant moderating effect on the influence of equity pledge on stock price crash *** interpretation tests excluded the tunnel effect and pressure effect by shareholders and incentive effect by *** study by analysing empirical data provides evidence on the change of investors’risk recognition,which is caused by financial shock,in the chinese capital market.

关键词： Equity pledge stock price crash risk leverage effect financial shock

Single channel source separation of radar fuze mixed signal based on phase difference analysis

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Defence Technology（防务技术） 2014年第3期10卷 308-315页

作者： Hang ZHU Shu-ning ZHANG Hui-chang ZHAO School of Electronic and Optical Engineering Nanjing University of Science and Technology Unit 73015 of PLA

A new method based on phase difference analysis is proposed for the single-channel mixed signal separation of single-channel radar *** method is used to estimate the mixing coefficients of de-noised signals through the cumulants of mixed signals,solve the candidate data set by the mixing coefficients and signal analytical form,and resolve the problem of vector ambiguity by analyzing the phase *** signal separation is realized by exchanging data of the *** waveform similarity coefficients are calculated,and the time鈥攆requency distributions of separated signals are *** results show that the proposed method is effective.

关键词： Single channel source separation Radar fuze signal Phase difference analysis Vector ambiguity

Unsteady numerical simulation on helium cooldown process for the 650 MHz two-cell superconducting cavity

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Radiation Detection Technology and Methods 2019年第4期3卷 18-28页

作者： Mei Li Zhengze chang Shaopeng Li Rui Ge Institution of High Energy Physics Chinese Academy of SciencesBeijing 100049China Key Laboratory of Partical Acceleration Physics and Technology CASBeijing 100049China Center for Superconducting RF and Cryogenics Institution of High Energy PhysicsBeijingChina

Background Superconducting cavity is usually needed to be gradually cooled from room temperature to the superconducting temperature zone(4.2 K and below)in the testing and sophisticated operation process of superconducting *** The purpose of this paper is to study the cooling law on the helium cooldown process for the 650 MHz two-cell superconducting cavity with the unsteady numerical *** A three-dimensional coupled heat-flow model of 650 MHz two-cell superconducting cavity was *** unsteady numerical simulation of different inlet temperatures,flow rates and pressure conditions was carried *** equiva-lent convective heat transfer coefficient and temperature distribution of 650 MHz two-cell superconducting cavity during cooldown process were *** effects of cooling time and entrance parameters on the cooldown process were *** The temperature distribution of the lower intersection lines has a large drop in the initial stage of cooldown process(120 s),while the temperature near the flanges at the both ends is still higher(remaining at the initial temperature of 300 K).With the passage of time,the temperature of the upper and lower intersection lines *** maximum temperature difference on the lower intersections is within 2 K in the final stage of cooldown process(3600 s).The maximum temperature difference increases by 180%,and the difference between the maximum temperature and the minimum temperature(dT)at the end of a cooldown stage increases by 130%after 1 h,respectively,when the inlet temperature drops from 290 to 270 K(under the condition of the initial temperature of 300 K).Conclusions The maximum temperature difference and the dT at the end of a cooldown stage increase with the decrease in the inlet *** maximum temperature difference increases with the increase in the inlet flow rate,while the dT at the end of a cooldown stage decreases with the increase in the inlet flow *** e

关键词： Accelerator Superconducting cavity Helium gas Cooldown process Unsteady numerical simulation

DISTRIBUTIONS OF VALONS IN NUCLEI AND EUROPEAN MUON COLLABORATION EFFECT

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chinese Physics Letters 1987年第5期4卷 221-224页

作者： ZHANG Chaoxi(chang Chaohsi) ZHU Wei Institute of Theoretical Physics Academia SinicaBeijing Physics Department East-China Normal UniversityShanghai

The new European Muon Collabovcition(EMC)effect in the low and the main regions of x may be understood by means of the valon picture,i.e.,the palon structure functions are universal but valon distribution function of ... 详细信息

关键词： distorted function distribution

Redox-Responsive Molecular Gels Based on Camptothecin Prodrug with Disulfide Linkage for Controlled and Sustained Drug Release

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Wuhan University Journal of Natural Sciences 2017年第5期22卷 411-419页

作者： chang Xiupeng LI Youmei CHEN Shu HE Feng ZHUO Renxi College of Chemistry and Molecular Science Wuhan UniversityWuhan 430072HubeiChina

A novel camptothecin （CPT） prodrug was successfully synthesized by conjugating CPT to adamantanecarboxylic acid （AD） via a cleavable disulfide linkage. The resulting CPT-ss-AD prodrug could act as a low molecular weight gelator to form molecular gels in water/water-miscible organic solvent mixture. Meanwhile, biode- gradable amphiphilic block copolymer mPEG-b-P （MAC-co-DTC）（PPMD） was also employed as an organic framework together with CPT-ss-AD to form gel structure. CPT-ss-AD/PPMD gel exhibited less compact molecular arrangement but much more stability than CPT-ss-AD gel. The two kinds of gels could effectively release the original CPT under reductive condition at a near-constant rate without any initial burst. As compared to CPT-ss-AD single-component gel, the two-component gel, CPT-ss-AD/PPMD, had a significantly higher release rate of CPT, while 3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide （MTT） assays also indicated highly potent cytotoxic activity against HeLa cells.

关键词： delivery prodrug molecular gels self-assembly polycarbonates

Shares Differences of Greenhouse Gas Emissions Calculated with GTP and GWP for Major Countries

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Advances in Climate change Research 2013年第2期4卷 127-132页

作者： WANG chang-Ke LUO Xin-Zheng ZHANG Hua Laboratory for Climate Studies National Climate Center China Meteorological Administration Yantai University

The global warming potential (GWP) and global temperature potential (GTP) are two common metrics to calculate the CO2 equivalent of greenhouse gases (GHGs). If the country's GHG emissions are calculated with GTP instead of GWP, the shares of the EU, USA, Japan, Canada and South Africa rise in the period 1990-2005, and those of Brazil, Australia, china, India, Mexico and Russia decrease. From 2015 to 2030, the projected shares of the EU, USA, Japan and china will increase, but those of Russia, Canada, Australia, India, Mexico and Brazil will decrease. The reduced shares of Brazil and Australia and increased share of the EU might be one of the important reasons that Brazil and Australia suggested to adopt GTP instead of GWP as early as possible, but the EU opposed it.

关键词： greenhouse gas global warming potential global temperature potential

Tracing runoff components in the headwater area of Heihe River by isotopes and hydrochemistry

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Journal of Groundwater Science and Engineering 2022年第4期10卷 405-412页

作者： Han Zhang Zong-yu Chen chang-yuan Tang Key Laboratory of Groundwater Sciences and Engineering Ministry of Natural Resources.Zhengding 050803HebeiChina Institute of Hydrogeology and Environmental Geology Chinese Academy of Geological SciencesShijiazhuang 050061China Comprehensive Survey and Management Center for Natural Resources China Geological SurveyBeijing 100055China Chiba University Matsudo 6482718510ChibaJapan

Since water resources of the Heihe River Basin are primarily in the form of surface runoff in the Qilian Mountains,identifying its sources and components is essential for researchers to understand water cycling and transformation in the *** will help to properly exploit water resources,and contribute to ecological environment *** paper uses the isotope data of hydrogen and oxygen in water and hydrochemistry data collected at a high altitude to trace the sources of surface runoff in Heihe River in rainy season and uses the three-component mixing model to estimate the contribution of each component to *** indicate that surface water consists of precipitation,melt water and groundwater,with precipitation being the primary component and contributing to 59%-64%of *** water and groundwater account for 15%-25%and 12%-22%,*** accounts for 60%,groundwater for 22%and glacial melt water for 18%of the outflow in the main stream of the Heihe *** composition is of great significance for water cycling and conversion research as well as water resource evaluation and management.

关键词： Qilian Mountains Components of surface runoff Isotope Mixing model

Genome-wide association studies:inherent limitations and future challenges

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Frontiers of Medicine 2012年第4期6卷 444-450页

作者： Yan Du Jiaxin Xie Wenjun chang Yifang Han Guangwen Cao Department of Epidemiology Second Military Medical UniversityShanghai 200433China

Genome-wide association studies(GWAS)have achieved great success in identifying genetic variants related to complex human diseases such as cancer and have provided valuable insights into their genetic ***,GWAS is quite the fashion in ***,there are issues related to its *** work needs to be done in the post-GWAS *** sequencing followed by functional studies will be needed to elucidate the underpinning biological mechanisms and further translate GWAS findings into medical *** with pharmacogenomics,the success of GWAS in identifying genetic risk factors and genetic differences in drug response has been gradually enabling personalized *** this article,we used hepatocellular carcinoma(HCC)as an example to demonstrate some of the inherent limitations and summarized future challenges of GWAS.

关键词： genome-wide association studies(GWAS) genetic variant cancer limitation challenge

Pd-Catalyzed Transfer of Difluorocarbene for Three Component Cross-Coupling

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chinese Journal of Chemistry 2020年第12期38卷 1647-1650页

作者： Zhi-Wei Xu Wei Zhang Jin-Hong Lin Chuan-Ming Jin Ji-chang Xiao Hubei Key Laboratory of Pollutant Analysis and Reuse Technology College of Chemistry and Chemical EngineeringHubei Normal UniversityHuangshiHubei 435002China Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of Sciences345 Lingling RoadShanghai 200032China

Summary of main observation and conclusion Outstanding accomplishments have been achieved in the chemistry of difluorocarbene,but transitionmetal-catalyzed transfer of difluorocarbene for coupling remains a challenging ***,we describe a Pd-catalyzed coupling of difluorocarbene with two aryl carbon centers to give difluoromethylenation products,which cannot be obtained by any previous difluorocarbene-transformation method.

关键词： method. carbene catalyzed

Laguerre Minimal Surfaces in ■~3

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Acta Mathematica Sinica,English Series 2008年第11期24卷 1861-1870页

作者： Yu Ping SONG chang Ping WANG LMAM School of Mathematical Sciences Peking University Beijing 100871 P. R. China

Laguerre geometry of surfaces in R^3 is given in the book of Blaschke, and has been studied by Musso and Nicolodi, Palmer, Li and Wang and other authors. In this paper we study Laguerre minimal surface in 3-dimensional Euclidean space R^3. We show that any Laguerre minimal surface in R^3 can be constructed by using at most two holomorphic functions. We show also that any Laguerre minimal surface in R^3 with constant Laguerre curvature is Laguerre equivalent to a surface with vanishing mean curvature in the 3-dimensional degenerate space R0^3.

关键词： Laguerre geometry Laguerre minimal surfaces Laguerre Gauss map