维普中文期刊产品整合服务
66篇 您的检索式:作者名="Yang 4"
    题名 作者 年代 出处 被引量
1Sr-Nd isotopic compositions of the Changjiang sediments: Implications for tracing sediment sources显示文摘The suspended particulate and fine-grained floodplain sediments were collected from the main stream and tributaries of the Changjiang River for Sr-Nd isotopic measurements. The εNd(0) values gradually decrease downstream from -10.8 on average in the upper reaches to -12.3 in the lower reaches, whereas the 87Sr/86Sr ratios increase correspondingly, averaging 0.721899 and 0.725826 respectively in the upper and middle-lower reaches. The compositional variations primarily reflect the complex con- trols of provenance rocks, chemical weathering, and sediment characters between different catchments, among which the abnormal Sr-Nd isotopic compositions of the Yalong, Fujiang, Tuojiang and Yuanjiang rivers indicate the sediment provenance contributions from the Emeishan Basalt in the upper reaches and the old metamorphic and siliceous rocks in the middle-lower reaches. The Sr-Nd isotopic ratios of the Changjiang sediments can better reflect the average composition of weathered continental crust compared to other major rivers in the world because of the unique source rock types in the Changjiang drainage basin. The recognition of the Sr-Nd isotopic systematics of the Changjiang sediments will contribute to our understanding of the Changjiang evolution history and continental weathering processes during the Cenozoic, and also to reconstructing the paleoenvironmental changes in East China and the marginal seas.YANG ShouYe1?, JIANG ShaoYong2, LING HongFei2, XIA XiaoPing3, SUN Min3 & WANG DeJie4 1 State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China 2 State Key Laboratory for Mineral Deposit Research, Nanjing University, Nanjing 210093, China 3 Departmen of Earth Sciences, The University of Hong Kong, Hong Kong SAR, China 4 Development Research Center, China Geological Survey, Beijing 100083, China 2007Science China Earth Sciences2007,50,10:32
2Technical framework for Internetware: An architecture centric approach显示文摘Being a new software paradigm evolved by the Internet, Internetware brings many challenges to the traditional software methods and techniques. Sponsored by the national basic research program (973), researchers in China have developed an architecture centric technical framework for the definition, incarnation and engineering of Internetware. First of all, a software model for Internetware is defined for what to be, including that Internetware entities should be packaged as components, behaving as agents, interoperating as services, collaborating in a structured and on demand manner, etc. Secondly, a middleware for Internetware is designed and implemented for how to be, including that Internetware entities are incarnated by runtime containers, structured collaborations are enabled by runtime software architecture, Internetware can be managed in a reflective and autonomic manner, etc. Thirdly, an engineering methodology for Internetware is proposed for how to do, including the way to develop Internetware entities and their collaborations by transforming and refining a set of software architectures which cover all the phases of software lifecycle, the way to identify and organize the disordered software assets by domain modeling, etc.YANG FuQing1,2, Lü Jian3,4 & MEI Hong1,2 1 Key Laboratory of High Confidence Software Technologies (Peking University), Ministry of Education, Beijing 100871, China 2 School of Electronics Engineering and Computer Science, Peking University, Beijing 100871, China 3 State Key Laboratory for Novel Software Technology, Nanjing 210093, China 4 Department of Computer Science and Technology, Nanjing University, Nanjing 210093, China 2008Science in China(Series F)2008,51,6:33
3A statistical model for porous structure of rocks显示文摘The geometric features and the distribution properties of pores in rocks were in- vestigated by means of CT scanning tests of sandstones. The centroidal coordi- nates of pores, the statistic characterristics of pore distance, quantity, size and their probability density functions were formulated in this paper. The Monte Carlo method and the random number generating algorithm were employed to generate two series of random numbers with the desired statistic characteristics and prob- ability density functions upon which the random distribution of pore position, dis- tance and quantity were determined. A three-dimensional porous structural model of sandstone was constructed based on the FLAC3D program and the information of the pore position and distribution that the series of random numbers defined. On the basis of modelling, the Brazil split tests of rock discs were carried out to ex- amine the stress distribution, the pattern of element failure and the inosculation of failed elements. The simulation indicated that the proposed model was consistent with the realistic porous structure of rock in terms of their statistic properties of pores and geometric similarity. The built-up model disclosed the influence of pores on the stress distribution, failure mode of material elements and the inosculation of failed elements.JU Yang1,2, YANG YongMing1, SONG ZhenDuo3 & XU WenJing4 1 State Key Laboratory of Coal Resources and Safe Mining, China University of Mining & Technology, Beijing 100083, China 2 Department of Mechanical and Manufacturing Engineering, The University of Calgary, 2500 University Drive NW Calgary, AB T2N 1N4, Canada 3 China National Coal Mining Equipment Co. Ltd, Beijing 100011, China 4 Department of Materials and Metallurgy, The University of Utah, Salt Lake City, Utah 84112, USA 2008Science China(Technological Sciences)2008,51,11:21
4Quantum secure direct communication with cluster states显示文摘A quantum secure direct communication protocol with cluster states is proposed.Compared with the deterministic secure quantum communication protocol with the cluster state proposed by Yuan and Song(Int.J.Quant.Inform.,2009,7:689),this protocol can achieve higher intrinsic efficiency by using two-step transmission.The implementation of this protocol is also discussed.CAO WeiFeng 1,YANG YuGuang 3,4,5* & WEN QiaoYan 2 1 College of Electric and Information Engineering,Zhengzhou University of Light Industry,Zhengzhou 450002,China 2 State Key Laboratory of Networking and Switching Technology,Beijing University of Posts and Telecommunications,Beijing 100876,China 3 College of Computer Science and Technology,Beijing University of Technology,Beijing 100124,China 4 State Key Laboratory of Integrated Services Network,Xidian University,Xi’an 710071,China 5 State key Laboratory of Information Security Gradute University of Chinese Academy of Sciences,Beijing 100049,China 2010Science China(Physics,Mechanics & Astronomy)2010,53,7:20
5Multi-level decollement zones and detachment deformation of Longmenshan thrust belt,Sichuan Basin,southwest China显示文摘As is well known that many decollement layers were developed in the Longmenshan thrust belt,Si-chuan Basin,China. Through field investigation,explanation of seismic profiles and analysis of the balanced sections,we can divide the decollement zones into 3 categories: (1) the deep level decolle-ment zones,including the crust-mantle decollement layer,intracrustal decollement layer,and presinian basal decollement layer. The main structural styles of their deformation are the crust-mantle decoup-ling detachment deformation,the basal ductile shear deformation,etc.; (2) the middle level decollement zones,including the Cambrian-Ordovician decollement layer,the Silurian decollement layer,etc.,the main structural styles of their deformation are the isopachous fold,the angular fold,the saddle struc-ture,and the combination styles of them; and (3) the shallow level decollement zones,including the Xujiahe Formation decollement layer of Upper Triassic and the Jurassic decollement layers,the main structural styles of their deformation are the thrust-nappe tectonic,the pop-up,the triangle zone ,the duplex,etc. Multi-level decollement zones not only made the Longmenshan thrust belt develop many different deformation styles from deep place to shallow place,but also made some local areas have the superimposition of the tectonic deformation apparently. This study indicates that the multi-level de-collement zones have a very important effect on the shaping and evolution of the Longmenshan thrust belt.TANG LiangJie1,2,3,YANG KeMing4,JIN WenZheng1,2,3,L ZhiZhou4 & YU YiXin1,2,3 1 State Key Laboratory of Petroleum Resource and Prospecting,China University of Petroleum,Beijing 102249,China 2 Key Laboratory for Hydrocarbon Accumulation Mechanism,China University of Petroleum,Ministry of Education,Beijing 102249,China 3 Basin and Reservoir Research Center,China University of Petroleum,Beijing 102249,China 4 Southwest Division Company,SINOPEC,Chengdu 610081,China 2008Science China Earth Sciences2008,51,S2:18
6Formation mechanism of carbonate cemented zones adjacent to the top overpressured surface in the central Junggar Basin,NW China显示文摘Carbonate cemented zones are normally adjacent to the top overpressured surface in the central Junggar Basin,NW China.Stable carbon and oxygen isotopic compositions and petrological investigations of carbonate cements in the carbonate cemented zones indicate that:(1) carbonate cements are composed dominantly of ferrocalcite,ferroan dolomite,and ankerite;(2) carbonate cements are formed under a high temperature circumstance in the subsurface,and organic fluid migration has an important effect on the formation of them;and(3) carbon and oxygen ions in the carbonate cements migrate from the underlying overpressured system.This suggests that the occurrence of carbonate cemented zones in this region results from multiple phases of organic fluid expulsion out of the overpressure compartment through geological time.This study provides a plausible mechanism of the formation of carbonate cemented zones adjacent to the top overpressured surface in the clastic sedimentary basins,and has an important implication for understanding the internal correlation between the formation of carbonate cemented zones adjacent to top overpressured surface and geofluids expulsion out of overpressured system.YANG Zhi1,2,ZOU CaiNeng1,3,HE Sheng2,LI QiYan1,HE ZhiLiang3,WU HengZhi5,CAO Feng1,MENG XianLong4,WANG FuRong2 & XIAO Qilin21 State Key Laboratory of EOR,Research Institute of Petroleum Exploration & Development,PetroChina,Beijing 100083,China 2 Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education,China University of Geosciences,Wuhan 430074,China 3 State Key Laboratory of EOR,Research Institute of Petroleum Exploration & Development,Petrochina,Beijing 100083,China 4 Research Institute of Petroleum Exploration and Production,SINOPEC,Beijing 100083,China 5 Southwest Branch Company,SINOPEC,Chengdu 610051,China 2010Science China Earth Sciences2010,53,4:12
7Multiparty simultaneous quantum identity authentication with secret sharing显示文摘Two multiparty simultaneous quantum identity authentication (MSQIA) protocols based on secret sharing are presented. All the users can be authenticated by a trusted third party (TTP) simultaneously. In the first protocol,the TTP shares a random key K with all the users using quantum secret sharing. The ith share acts as the authentication key of the ith user. When it is necessary to perform MSQIA,the TTP generates a random number R secretly and sends a sequence of single photons encoded with K and R to all the users. According to his share,each user performs the corresponding unitary operations on the single photon sequence sequentially. At last,the TTP can judge whether the impersonator exists. The sec-ond protocol is a modified version with a circular structure. The two protocols can be efficiently used for MSQIA in a network. They are feasible with current technol-ogy.YANG YuGuang1,2,WEN QiaoYan3 & ZHANG Xing4,5 1 College of Computer Science and Technology,Beijing University of Technology,Beijing 100022,China 2 State Key Laboratory of Information Security (Graduate University of the Chinese Academy of Sciences),Beijing 100049,China 3 School of Science,Beijing University of Posts and Telecommunications,Beijing 100876,China 4 Institute of Electronic Technology,Information Engineering University,Zhengzhou 450004,China 5 Trusted Computing Laboratory,Beijing University of Technology,Beijing 100022,China 2008Science China(Physics,Mechanics & Astronomy)2008,51,3:12
8A new elliptic-parabolic yield surface model revised by an adaptive criterion for granular soils显示文摘An adaptive criterion for shear yielding as well as shear failure of soils is proposed in this paper to address the fact that most criteria,including the Mohr-Coulomb criterion,the Lade criterion and the Matsuoka-Nakai criterion,cannot agree well with the experimental results when the value of the intermediate principal stress parameter is too big.The new criterion can adjust an adaptive parameter based on the experimental results in order to make the theoretical calculations fit the test results more accurately.The original elliptic-parabolic yield surface model can capture both soil contraction and dilation behaviors.However,it normally over-predicts the soil strength due to its application of the Extended Mises criterion.A new elliptic-parabolic yield surface mode is presented in this paper,which introduces the adaptive criterion in three-dimensional principal stress space.The new model can well model the stress-strain behavior of soils under general stress conditions.Compared to the original model which can only simulate soil behavior under triaxial compression conditions,the new model can simulate soil behaviors under both triaxial compression conditions and general stress conditions.LIU HanLong 1,2 ,XIAO Yang 1,2 ,LIU JinYuan 3 &LI GuoYing 4 1 Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University, Nanjing 210098,China 2 Geotechnical Research Institute,Hohai University,Nanjing 210098,China 3Department of Civil Engineering,Ryerson University,Toronto,Canada 4 Department of Geotechnical Engineering,Nanjing Hydraulic Research Institute,Nanjing 210014,China 2010Science China(Technological Sciences)2010,53,8:12
9Primary scientific results of Chang'E-1 lunar mission显示文摘The strategic plan for the development of the unmanned Chinese Lunar Exploration Program is characterized by three distinct stages: 'orbiting around', 'landing on' and 'returning from' the Moon. The first Chinese lunar probe, Chang'E-1, which was successfully launched on October 24th, 2007 at Xichang Satellite Launch Center, and guided to crash on the Moon on March 1st, 2009, at 52.36°E, 1.50°S, in the north of Mare Fecunditatis, is the first step towards the 'orbiting around' stage. The Chang'E-1 mission lasted 495 days, exceeding the expected life-span by about four months. A total of 1.37 TB raw data was received from Chang'E-1. It was then processed into 4 TB scientific data products at various levels. Many scientific results have been obtained by analyzing these data, including especially the 'global lunar image from the first Chinese lunar explora- tion mission'. All scientific goals of Chang'E-1 have been achieved. It provides much useful materials for further advances of lunar sciences and planetary chemistry. Meanwhile, these results will serve as a firm basis for future Chinese lunar missions.OUYANG ZiYuan1,2, LI ChunLai1, ZOU YongLiao1, ZHANG HongBo1, Lü Chang1, LIU JianZhong1, LIU JianJun1, ZUO Wei1, SU Yan1, WEN WeiBin1, BIAN Wei1, ZHAO BaoChang3, WANG JianYu4, YANG JianFeng3, CHANG Jin5, WANG HuanYu6, ZHANG XiaoHui7, WANG ShiJin7, WANG Min1, REN Xin1, MU LingLi1, KONG DeQing1, WANG XiaoQian1, WANG Fang1, GENG Liang1, ZHANG ZhouBin1, ZHENG Lei1, ZHU XinYing1, ZHENG YongChun1, LI JunDuo1, ZOU XiaoDuan1, XU Chun1, SHI ShuoBiao1, GAO YiFei1 & GAO GuanNan1 1 National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China 2 Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China 3 Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China 4 Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China 5 Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008, China 6 Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China 7 Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190, China 2010Science China Earth Sciences2010,53,11:11
10Revisiting the origin of modern humans in China and its implications for global human evolution显示文摘The debates over the origin of modern humans have long been centered on two competing theories:the 'Out-of-Africa'(single-place origin) theory and the 'Multi-regional Evolution' theory.China is an extremely important region where many ancient human fossils were collected along with numerous associated faunal remains and artefacts.These cultural remains,unearthed from different areas in the country and covering a long time span,will help clarify the controversy.The study of cultural materials in China is expected to shed important light on biological evolutionary patterns and social and technical developments of those early humans as well as their environmental conditions.Based on the analysis of Chinese fossils and associated materials,in conjunction with some genetic studies,this paper aims at evaluating each of the two theories in order to stimulate more discussions.Our study suggests that the evolutionary model of 'Continuity with Hybridization' is most relevant in reflecting the current understanding of human evolutionary history in China.Furthermore,we propose that the concept of regional diversity of evolutionary models should be seriously considered to illustrate different evolutionary modes applied to different parts of the world.GAO Xing1,2*,ZHANG XiaoLing1,2,3,YANG DongYa2,4,SHEN Chen2,5 & WU XinZhi1,2 1 Institute of Vertebrate Paleontology and Paleoanthropology,Chinese Academy of Sciences,Beijing 100044,China 2 Laboratory of Human Evolution,Chinese Academy of Sciences,Beijing 100044,China 3 Graduate University of Chinese Academy of Sciences,Beijing 100049,China 4 Department of Archaeology,Simon Fraser University,Vancouver V5A 1S6,Canada 5 The Royal Ontario Museum,Toronto M5S 2C6,Canada 2010Science China Earth Sciences2010,53,12:11
11Research on the dry intrusion accompanying the low vortex precipitation显示文摘By employing the 6.7μm satellite vapor cloud images and NCEP/NCAR 1°×1° reanalysis datasets, the characteristics and mechanism of the dry intrusion, as well as its impacts on the low vortex precipita- tion at the Meiyu front are explored in this paper. It is found that the formation,development and main- tenance of the low vortex precipitation at the Meiyu front are closely related to the evolution of the dry intrusion. The dry intrusion is characterized by high potential vorticity (PV), low humidity and cold air. The dry intrusion exhibits as an obvious dark zone on vapor cloud images, an area in which atmos- pheric relative humidity is lower than 60%. However, the features of the dry intrusion on the vapor im- ages are clearer than that of the humidity field, for the former is the digital vapor cloud images with high temporal and spatial resolution, and it can be used to explore the finer characteristics of the develop- ment, evolution and supplement of the intrusion during the development of the low vortex. The dry intrusion impacts accompanying the low vortex precipitation at the Meiyu front come from all levels of the troposphere, with the strongest intrusion located at the upper troposphere. The dry and cold air intrudes the vicinity of the low vortex from the upper isentropic surface to the lower one, slanting eastward from lower to higher level. The low vortex precipitation region is usually situated in front of the dry intrusion where the relative humidity gradient is higher. The research also reveals that the mechanism of the dry intrusion is that the high potential vorticity descends from the upper troposphere to the lower level, therefore, the dry intrusion can be used as an important index of the high PV forcing. To the west of the low vortex precipitation, the upper level northerlies descend across the isentropic surface, then the dry cold advection can trigger the instable development in the mid-low troposphere. The dry intrusion enhances the low vortex precipitation. Meanwhile, because of the good agreement between the high PV at the upper level and the dry intrusion illustrated by the vapor cloud images, the dry intrusion in the vapor cloud images is the direct and clear description of the high PV forcing which provides a new insight in understanding the evolution and development of the practical weather sys- tems. Besides, both the skills of isentropic analysis and potential temperature coordinates system analysis are important to revealing the three-dimension structure of the dry intrusion.YAO XiuPing1,2,3, WU GuoXiong1, ZHAO BingKe4, YU YuBin3 & YANG GuiMing2,5 1 LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China 2 Institute of Heavy Rain, China Meteorological Administration, Wuhan 430074, China 3 China Meteorological Administration Training Center, Beijing 100081, China 4 Shanghai Typhoon Institute of China Meteorological Administration, Shanghai 200030, China 5 National Meteorological Center of the China Meteorological Administration, Beijing 100081, China 2007Science China Earth Sciences2007,50,9:11
12Arsenic trioxide promotes mitochondrial DNA mutation and cell apoptosis in primary APL cells and NB4 cell lines显示文摘This study aimed to investigate the effects of arsenic trioxide(As2O3) on the mitochondrial DNA(mtDNA) of acute promyelocytic leukemia(APL) cells.The NB4 cell line was treated with 2.0 μmol/L As2O3 in vitro,and the primary APL cells were treated with 2.0 μmol/L As2O3 in vitro and 0.16 mg kg-1 d-1 As2O3 in vivo.The mitochondrial DNA of all the cells above was amplified by PCR,directly sequenced and analyzed by Sequence Navigatore and Factura software.The apoptosis rates were assayed by flow cytometry.Mitochondrial DNA mutation in the D-loop region was found in NB4 and APL cells before As2O3 use,but the mutation spots were remarkably increased after As2O3 treatment,which was positively correlated to the rates of cellular apoptosis,the correlation coefficient:rNB4-As2O3=0.973818,and rAPL-As2O3=0.934703.The mutation types include transition,transversion,codon insertion or deletion,and the mutation spots in all samples were not constant and regular.It is revealed that As2O3 aggravates mtDNA mutation in the D-loop region of acute promyelocytic leukemia cells both in vitro and in vivo.Mitochondrial DNA might be one of the targets of As2O3 in APL treatment.MENG Ran1,ZHOU Jin2,SUI Meng3,LI ZhiYong4,FENG GuoSheng1 & YANG BaoFeng2 1 Division of Neurology,the Ninth Clinical Medical College of Beijing University(Shijitan Hospital),Beijing 100038,China 2 The First Hospital of Harbin Medical University,Harbin 150001,China 3 Management Information System,University of International Business and Economics,Beijing 100029,China 4 Department of Radiology,Cambridge University Hospitals NHS Foundation Trust Box 219 Level 5,Addenbrooke’s Hospital Cambridge CB2 0QQ,UK 2010Science China(Life Sciences)2010,53,1:10
13Threshold quantum secret sharing between multi-party and multi-party显示文摘A threshold quantum secret sharing (TQSS) scheme between multi-party and multi-party was proposed using a sequence of single photons,which is useful and efficient when the parties of communication are not all present. We described the process of this TQSS scheme and discussed its security. It was shown that entan-glement is not necessary for quantum secret sharing. Moreover,the theoretic effi-ciency was improved to approach 100% as almost all the instances can be used for generating the private key,and each photon can carry one bit of information. This protocol is feasible with the present-day technique.YANG YuGuang1,2,3 & WEN QiaoYan4 1 College of Computer Science and Technology,Beijing University of Technology,Beijing 100124,China 2 State Key Laboratory of Integrated Services Network,Xidian University,Xi’an 710071,China 3 State Key Laboratory of Information Security (Graduate University of Chinese Academy of Sciences),Beijing 100049,China 4 State Key Laboratory of Networking and Switching Technology,Beijing University of Posts and Tele-communications,Beijing 100876,China 2008Science China(Physics,Mechanics & Astronomy)2008,51,9:8
14Genomic research for important pathogenic bacteria in China显示文摘Rapid accumulation of bacterial genomic data offered an unprecedented opportunity to understand bacterial biology from a holistic view of point.We can thus closely look at the way in which a pathogen is evolved,and these data has been applied to molecular epidemiology and microbial forensics,and screening of novel diagnostic,vaccine and drug targets.The newly developed high-throughput low-cost sequencing technologies,such as 454,Solexa and SOLiD,will promote the acquisition and application of genomic data in new research areas that we dared not imagine previously,such as the metagenomics of human gastric-intestinal tract,for better and comprehensive understanding of human health and disease.YANG RuiFu1,GUO XiaoKui2,YANG Jian3,JIANG YongQiang1,PANG Bo4,CHEN Chen5,YAO YuFeng2,QIN JinHong2 & LI QingTian2 1 Laboratory of Analytical Microbiology,State Key Laboratory of Pathogen and Biosecurity,Beijing Institute of Microbiology and Epidemiology,Beijing 100071,China 2 Department of Medical Microbiology and Parasitology,Institutes of Medical Sciences,Shanghai Jiao Tong University School of Medicine,Shanghai 200025,China 3 State Key Laboratory for Molecular Virology and Genetic engineering,Institute of Pathogen Biology,Chinese Academy of Medical Sciences,Beijing 100176,China 4 State Key Laboratory for Infectious Disease Prevention and Control,Institute for Communicable Disease Control and Prevention,Chinese Center for Disease Control and Prevention,Beijing 102206,China 5 Beijing Genomics Institute at Shenzhen,Shenzhen 518083,China 2009Science China(Life Sciences)2009,52,1:8
15Role of uterine natural killer cells in angiogenesis of human decidua of the first-trimester pregnancy显示文摘Decidualization is accompanied by extensive angiogenesis, which is an essential step in the maturation of new blood vessels in mammalian pregnancy. The purpose of this study was to determine a distribution of uNK cells (CD56+ uNK or CD56bright cells) in human decidua of the first-trimester pregnancy, and investigate whether uNK cells in human decidua could express vascular endothelial growth factor (VEGF-A) and/or angiopoietin2 (Ang2). Our immunohistochemical staining results demonstrated that a great amount of uNK (CD56+) cells scattered throughout the decidual stroma and near endometrial gland and spiral vessels in human decidua. The protein expression of VEGF-A and Ang2 was detected in decidual stroma cells, capillary endothelial cells and glandular cells in tissue specimens. There was a positive correlation between microvessel density (MVD) and the number of the CD56-positive uNK cells in decidual stroma, and also between the number of the CD56-positive uNK cells and VEGF-A protein expression in the tissue. In addition, we found that uNK cells in human decidua could express VEGF-A mRNA, but not Ang2 mRNA, in isolated uNK cells in human decidua of the first-trimester gestation by combination of LCM and Nested-PCR. Our study indicated that uNK cells, through expressing VEGF-A, may play an important role in the angiogenic response at the time of human decidualization and early placenta development.LI GuoHua1, HUANG Wei1, XIA QingJie2, YANG KaiXuan3, LIU RaoFang1, ZHU HuiLi1 & JIANG Wei4 1 Department of Reproductive Endocrinology, West China Second University Hospital, Sichuan University, Chengdu 610041, China 2 West China Research Laboratory of Molecular Genetics, Sichuan University, Chengdu 610041, China 3 Department of Pathology, West China Second University Hospital, Sichuan University, Chengdu 610041, China 4 Department of Pathology, West China Hospital, Sichuan University, Chengdu 610041, China 2008Science China(Life Sciences)2008,51,2:7
16Treatment of rotaviral gastroenteritis with Qiwei Baizhu powder显示文摘AIM To observe the effects of Qiwei Baizhu Powder ( QWBZP) on rotaviral gastroenteritis in children and in animal models.``METHODS Enrolled patients were divided into two groups, and one group was treated with oral rehydration solution(ORS) and the other treated with oral liquid of QWBZP. Neonate mice were orally infected with 50 μLrotavirus suspension (4 × l0s PFU/mL) and treated with ORS or oral liquid of QWBZP, respectively.``RESULTS Eighty-three cases of rotaviral gastroenteritis treated with QWBZP revealed a better efficacy than that treated with ORS (x2 - 10.8T, P<0.05). The contents of sodium and glucose as well as number of patients with positive human rotavirus antigen in stool in QWBZP group were all less than that in ORS group. In animal models,QWBZP was found effective in treating rotavirus gastroenteritis in neonate NIH mice, as compared with control groups. In QWBZP group, the mortality of infected mice was decreased by 73.3%, the body weight of infected mice was increased, the contents of sodium and glucose as well as number of mice with positive rotavirus antigen in feces were significantly reduced, and the pathological changes such as damage of small intestinal mucosa and villi were also obviously alleviated.``CONCLUSION QWBZP has effects on improving the absorptive function of small intestine, shortening the duration of diarrhea and rotavirus shedding from stool and alleviating the pathological changes of small intestine induced by rotavirus.Shuang-Teng He~1 Fei-Zhou He~2 Can-Rong Wu~3 Shun-Xiang Li~2 Wei-Xin Liu~4 Yong-Fang Yang~2 Shi-Sheng Jiang~2 Gang He~1 1 Institute of Combined Traditional Chinese and Western Medicine,Xiangya Hospital,Hunan Medical University,Changsha,410008,China2 Hunan Province Academy of Traditional Chinese Medicine,Changsha 410006,China3 Department of Microbiology,Hunan College of Traditional Chinese Medicine,Changsha 410007,China4 Department of Pediatrics,The Second Hospital of Shuangfeng County,Hunan Province,411700,China 2001World Journal of Gastroenterology2001,7,5:6
17Threshold proxy quantum signature scheme with threshold shared verification显示文摘A threshold proxy quantum signature scheme with threshold shared verification is proposed. An original signer could authorize a group as its proxy signers. Then only t or more of n persons in the proxy group can generate the proxy signature on behalf of the original signer and any t-1 or fewer ones cannot do that. When the proxy signature needs to be verified,any t or more of n persons belonging to the verification group can verify the message and any t-1 or fewer ones cannot verify the validity of the proxy signature.YANG YuGuang1,3,4 & WEN QiaoYan2 1 College of Computer Science and Technology,Beijing University of Technology,Beijing 100124,China 2 State Key Laboratory of Networking and Switching Technology,Beijing University of Posts and Tele-communications,Beijing 100876,China 3 State Key Laboratory of Integrated Services Network,Xidian University,Xi’an 710071,China 4 State Key Laboratory of Information Security(Graduate University of Chinese Academy of Sciences) ,Beijing 100049,China 2008Science China(Physics,Mechanics & Astronomy)2008,51,8:6
18The role of the DLPFC in inductive reasoning of MCI patients and normal agings:An fMRI study显示文摘Previous studies of young people have revealed that the left dorsolateral prefrontal cortex(DLPFC) plays an important role in inductive reasoning.An fMRI experiment was performed in this study to examine whether the left DLPFC was involved in inductive reasoning of MCI patients and normal agings,and whether the activation pattern of this region was different between MCI patients and normal agings.The fMRI results indicated that MCI patients had no difference from normal agings in behavior performance(reaction time and accuracy) and the activation pattern of DLPFC.However,the BOLD response of the DLPFC region for MCI patients was weaker than that for normal agings,and the functional connectivity between the bilateral DLPFC regions for MCI patients was significantly higher than for normal agings.Taken together,these results indicated that DLPFC plays an important role in inductive reasoning of agings,and the functional abnormity of DLPFC may be an earlier marker of MCI before structural alterations.YANG YanHui1,3,LIANG PeiPeng2,3,LU ShengFu2,3,LI KunCheng1,3 & ZHONG Ning2,3,4 1 Xuanwu Hospital,Capital Medical University,Beijing 100053,China 2 The International WIC Institute,Beijing University of Technology,Beijing 100124,China 3 Beijing Municipal Lab of Brain Informatics,Beijing 100124,China 4 Department of Life Science and Informatics,Maebashi Institute of Technology,Maebashi 371-0816,Japan 2009Science China(Life Sciences)2009,52,8:5
19Gradient analysis of landscape spatial and temporal pattern changes in Beijing metropolitan area显示文摘The gradient based landscape metrics analysis is now widely used to study the landscape pattern changes in respond to the urbanization.In order to discover the trend of spatio-temporal changes in Beijing metropolitan area during the past 15 years,several landscape metrics are computed using a moving window along a 96 km long transect across Beijing metropolitan area from west to east.Specially,the spatial extent of sub-landscape,which is determined by the moving window’s size,is profoundly examined.The results show that the metrics varies smoothly and regularly along the selected transect when the window size is greater than 6 km×6 km,and irregularly fluctuated for the smaller window size,that the spatial and temporal landscape characteristics of Beijing city match the hypothetical framework of spatio-temporal urban sprawl in the form of alternating processes of diffusion and coalescence well,and that some new trends of the urban sprawl style in Beijing metropolitan area,such as leap-frog manner,are also detected by the gradient landscape analysis.YANG YeTao1,ZHOU QiMing2,GONG JianYa3 & WANG YingYing4 1 Institute of Geophysics and Geomatics,China University of Geosciences,Wuhan 430074,China 2 Department of Geography,Hong Kong Baptist University,Hong Kong 3 State Key Laboratory of Information Engineering in Surveying,Mapping and Remote Sensing,Wuhan University,Wuhan 430074,China 4 Hubei Provincial Bureau of Meteorology,Wuhan 430074,China 2010Science China(Technological Sciences)2010,53,S1:5
20A first-principles study of the size-dependent electronic properties of SiC nanotubes显示文摘We investigate the structural and electronic properties of SiC nanotubes(NTs) with hexagonal cross sections by a first-principles calculation using plane-wave ultra-soft pseudo-potential technology based on the density-functional theory.Our results reveal that surface-layer C and Si atoms relax significantly upon decreasing the tube-wall thickness because of surface-size and quantum-size effects.We also find that all relaxed SiC NTs stay stably on the nanoscale because of an admixture of sp2 and sp3 hybridization between C and Si atoms and a strong covalent,and that the band gap tends to decrease with increasing tube-wall thickness.Our calculations further indicate that both C and Si atoms on the inner and outer surface of SiC NTs contribute to defect states at the top of the valence band and at the bottom of the conduction band.These results provide reference information for a thorough understanding of the properties of SiC nanostructures and also enable more precise monitoring and control of the growth of SiC nanostructures.ZHANG WeiHu 1,2,3,ZHANG FuChun 3,ZHANG ZhiYong 4*,LU ShuYuan 5 & YANG YanNing 3 1 Xi’an Institute of Optics and Precision Mechanics,Chinese Academy of Sciences,Xi’an 710068,China 2 Graduate University of Chinese Academy of Sciences,Beijing 100049,China 3 College of Physics and Electronic Information,Yan’an University,Yan’an 716000,China 4 College of Information Science and Technology,Northwest University,Xi’an 710127,China 5 Department of Telecommunications,Xi’an Institute of Posts and Telecommunications,Xi’an 710121,China 2010Science China(Physics,Mechanics & Astronomy)2010,53,7:4
返回顶部 每页显示:
共4页 首页 上一页 第1页 下一页 末页 /4 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费