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1Apoptosis and its relationship with cell proliferation,p53,Waf1p21,bcl-2 and c-mycin esophageal carcinogenesis studied with a high-risk population in northern China显示文摘Apoptosisanditsrelationshipwithcelproliferation,p53,Waf1p21,bcl2andcmycinesophagealcarcinogenesisstudiedwithahighriskpopul...WANG LiDong1, ZHOU Qi1, WEI JunPing1, YANG WanCai1, ZHAO Xin1, WANG LiXia1, ZOU Jian Xiang1, GAO ShanShan1, LI YongXin1 and YANG C.S.2Keywords esophageal neoplasms apoptosis precancerous lesions Waf1 p21 gene p53 1998World Journal of Gastroenterology1998,4,4:295
2Influence of the impounding process of the Three Gorges Reservoir up to water level 172.5m on water eutrophication in the Xiangxi Bay显示文摘The water level of the Three Gorges Reservoir(TGR) rose to 172.5 m in two stages from September to November,2008.The hydrodynamic parameters and water quality parameters(e.g.flow velocity,temperature,turbidity and nutrient content) had been continuously monitored to reveal the influence of the impounding process of the TGR on the water eutrophication in the Xiangxi Bay(XXB).The maximal daily rise of the water level of the TGR was about 2.38 m.The water exchange between the mainstream(the Changjiang River) and the XXB of the TGR was enhanced by density current,and its main characteristics were a density-stratified flow in different directions.The water exchange reduced the differences of the water quality parameters(for example,temperature,turbidity,nutrient level,pH,etc.) between the mainstream and the XXB during the impounding process.Meanwhile,the water stability index in the mainstream remained small but it was lowered in the XXB.The main causes included the dilution by water of lower concentration of the chlorophyll a(Chl.a) entering from the mainstream,the decline of the water stability,and the increase of suspended silt,which induced the Chl.a to decrease in the XXB during the impounding process.The grade of the water eutrophication changed from middle eutrophic level to mesotrophic state in the process.However,as available nutrients were imported into the XXB from the mainstream during the impounding process the risk of water eutrophication increases in the XXB in the future.YANG ZhengJian1,LIU DeFu1,JI DaoBin1,2 & XIAO ShangBin1,3 1 College of Civil & Hydroelectric Engineering,China Three Gorges University,Yichang 443002,China 2 School of Water Resources & Hydropower Engineering,Wuhan University,Wuhan 430072,China 3 Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710075,China 2010Science China(Technological Sciences)2010,53,4:58
3The deformation pattern and fault rate in the Tianshan Mountains inferred from GPS observations显示文摘Based on GPS measurements conducted from 1992 to 2006, we present the current crustal movement velocity field for approximately 400 sites in the Tianshan Mountains and their adjacent areas, and estimate slip rates on the major faults using a 2-D elastic dislocation model. Our studies show slip rates within the range of 1―4 mm/a on the NW-SE trending strike-slip faults (such as Talas-Fergana fault) in the Tianshan Mountains. We also found the slip rates on the approximately WE-SN trending gently-dipping detachment fault vary from 10―13 mm/a for the southwest Tianshan Mountains to 2―5 mm/a for the eastern Tianshan Mountains, and to 6―12 mm/a for the Kyrgrz Tianshan. The GPS velocity field reveals that the total convergence is not uniformly distributed across the Tianshan Mountains, with 80%―90% of the N-S shortening absorbed along the southern and northern edges, and relatively little deformation accommodated within the interior. This first-order feature of strain pattern is explained best by underthrusting of adjacent blocks beneath the Tianshan Mountains along a basal detachment fault. We found the occurrence of historical M7―8 earthquakes somewhere in the locked ramp that connects the creeping and locking segments of the detachment, thereby resulting in elastic strain concentration and accumulation around it. The elastic strain confined in the upper crustal layer above the detachment ultimately releases through infrequent great earthquakes in the Tianshan Mountains, resulting in considerable folding and faulting at their margins. The Tianshan Mountains propagated outward and rose progressively as a wedge-shaped block.YANG ShaoMin1,2, LI Jie1,3 & WANG Qi2,1 1 Research Center of Space Science and Technology, China University of Geosciences, Wuhan 430074, China 2 Institute of Seismology, China Earthquake Administration, Wuhan 430071, China 3 Earthquake Administration of Xinjiang Uygur Autonomous Region, Urumqi 830011, China 2008Science China Earth Sciences2008,51,8:43
4Sr-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
5Numerical simulation of mechanisms of deformation,failure and energy dissipation in porous rock media subjected to wave stresses显示文摘The pore characteristics,mineral compositions,physical and mechanical properties of the subarkose sandstones were acquired by means of CT scan,X-ray diffraction and physical tests.A few physical models possessing the same pore characteristics and matrix properties but different porosities compared to the natural sandstones were developed.The 3D finite element models of the rock media with varied porosities were established based on the CT image processing of the physical models and the MIMICS software platform.The failure processes of the porous rock media loaded by the split Hopkinson pressure bar(SHPB) were simulated by satisfying the elastic wave propagation theory.The dynamic responses,stress transition,deformation and failure mechanisms of the porous rock media subjected to the wave stresses were analyzed.It is shown that an explicit and quantitative analysis of the stress,strain and deformation and failure mechanisms of porous rocks under the wave stresses can be achieved by using the developed 3D finite element models.With applied wave stresses of certain amplitude and velocity,no evident pore deformation was observed for the rock media with a porosity less than 15%.The deformation is dominantly the combination of microplasticity(shear strain),cracking(tensile strain) of matrix and coalescence of the cracked regions around pores.Shear stresses lead to microplasticity,while tensile stresses result in cracking of the matrix.Cracking and coalescence of the matrix elements in the neighborhood of pores resulted from the high transverse tensile stress or tensile strain which exceeded the threshold values.The simulation results of stress wave propagation,deformation and failure mechanisms and energy dissipation in porous rock media were in good agreement with the physical tests.The present study provides a reference for analyzing the intrinsic mechanisms of the complex dynamic response,stress transit mode,deformation and failure mechanisms and the disaster mechanisms of rock media.JU Yang1,2,WANG HuiJie1,YANG YongMing1,HU QinAng3 & PENG RuiDong1 1 State Key Laboratory of Coal Resources and Safe Mining,Beijing Key Laboratory of Fracture and Damage Mechanics of Rock and Concrete,China University of Mining and Technology,Beijing 100083,China 2 Department of Mechanical and Manufacturing Engineering,University of Calgary,Calgary,Alberta,T2N 1N4,Canada 3 School of Environment and Civil Engineering,College of Engineering,Oklahoma State University,Stillwater,OK 74078,USA 2010Science China(Technological Sciences)2010,53,4:32
6Targeting Gene-Virotherapy of Cancer and its prosperity显示文摘为癌症的基因和病毒的治疗显示出一些治疗学的效果,但是有真实突破的缺乏。为了达到肿瘤的完全的消除的目标,在动物的异种皮移植当模特儿,我们开发了叫的新策略指向癌症的 Gene-Virotherapy,它试图联合基因治疗和 virotherapy 的优点。这新策略独自比基因或病毒的治疗生产了更强壮的反肿瘤效果。肿瘤特定的 replicative 侵入人体气管粘膜的病菌向量,指定了为 ZD55,被侵入人体气管粘膜的病菌的 55kDa E1B 区域的删除构造。结果病毒的构造不仅由明确地指向 p53 保留类似的功能到 ONYX-015 否定肿瘤,而且允许各种各样的治疗学的基因到的插入由于最新介绍的克隆的地点形成适当 ZD55 衍生物,与原来的 ONYX-015 病毒不可行的一项任务。我们证明反肿瘤一如此的衍生物完成, ZD55-IL-24,比 ZD55 virotherapy 或 Ad-IL-24 基因治疗的是乘更多的有势力的至少 100。不过,由 ZD55-IL-24 的使用的肿瘤质量的完全的消除是仅仅在一些然而并非所有老鼠观察了,显示那一治疗学的基因不对“痊愈”足够这些老鼠。有互补或合作的效果的基因是什么时候,独立克隆进 ZD55 向量并且在联合使用了(指定了为双基因治疗策略) ,好一些的结果被获得;并且如果二合适的基因被选择,在所有老鼠完成所有异种皮移植肿瘤群众的完全的消除是可能的。更全面的研究将多半为临床的试用基于这新策略导致一个协议。最后,为癌症治疗的两倍控制指向的病毒双的基因治疗的概念,和在癌症干细胞的最近的进步的含意也被讨论。Xin Yuan Liu~(1,2) ~1Institute of Biochemistry and Cell Biology,Shanghai Institutes for Biological Sciences,Chinese Academy of Sciences,320 Yue Yang Road,Shanghai 200031,China ~2Xinyuan Institute of Medicine and Biotechnology,School of Life Science,Zhejiang Sci-Tech University,Hangzhou 310018,China 2006Cell Research2006,16,11:32
7Technical 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
8Above-and belowground biomass in relation to envi- ronmental factors in temperate grasslands, Inner Mongolia显示文摘Above- and belowground biomasses of grasslands are important parameters for characterizing re- gional and global carbon cycles in grassland ecosystems. Compared with the relatively detailed in- formation for aboveground biomass (AGB), belowground biomass (BGB) is poorly reported at the re- gional scales. The present study, based on a total of 113 sampling sites in temperate grassland of the Inner Mongolia, investigated regional distribution patterns of AGB, BGB, vertical distribution of roots, and their relationships with environmental factors. AGB and BGB increased from the southwest to the northeast of the study region. The largest biomass occurred in meadow steppe, with mean AGB and BGB of 196.7 and 1385.2 g/m2, respectively; while the lowest biomass occurred in desert steppe, with an AGB of 56.6 g/m2 and a BGB of 301.0 g/m2. In addition, about 47% of root biomass was distributed in the top 10 cm soil. Further statistical analysis indicated that precipitation was the primary determinant factor in shaping these distribution patterns. Vertical distribution of roots was significantly affected by precipitation, while the effects of soil texture and grassland types were weak.MA WenHong1,2, YANG YuanHe1, HE JinSheng1, ZENG Hui1,2 & FANG JingYun1 1 Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China 2 School of Environment & Urban Study, Peking University Shenzhen Graduate School, Shenzhen 518055, China 2008Science China(Life Sciences)2008,51,3:34
9Dissection of genetic overlap of salt tolerance QTLs at the seedling and tillering stages using backcross introgression lines in rice显示文摘QTLs for salt-tolerance(ST)related traits at the seedling and tillering stages were identified using 99 BC2F8 introgression lines(IL)derived from a cross between IR64(indica)as a recurrent parent and Binam(japonica)from Iran as the donor parent.Thirteen QTLs affecting survival days of seedlings(SDS), score of salt toxicity of leaves(SST),shoot K + concentration(SKC)and shoot Na + concentration(SNC) at the seedling stage and 22 QTLs underlying fresh weight of shoots(FW),tiller number per plant(TN) and plant height(PH)at the tillering stage were identified.Most QTLs detected at the tillering stage showed obvious differential expression to salt stress and were classified into three types based on their differential behaviors.Type I included 11 QTLs which were expressed only under the non-stress condition.Type II included five QTLs expressed in the control and the salt stress conditions,and three of them(QPh5,QPh8 and QTn9)had similar quantity and the same direction of gene effect,suggesting their expression was less influenced by salt stress.Type III included six QTLs which were detectable only under salt stress,suggesting that these QTLs were apparently induced by the stress.Thirteen QTLs affecting trait difference or trait stability of ILs between the stress and non-stress conditions were identified and the Binam alleles at all loci except QPh4,QTn2 and QFw2a decreased trait difference.The three QTLs less influenced by the stress and 13 QTLs affecting trait stability were considered as ST QTLs which contributed to ST.Comparing the distribution of QTLs detected at the seedling and tillering stages,most(69%)of them were genetically independent.Only four were the same or adjacent regions on chromosomes 1,2,8 and 11 harboring ST QTLs detected at the two stages,suggesting that partial genetic overlap of ST across the two stages occurs.It is likely,therefore,to develop ST rice variety for both stages by pyramiding of ST QTLs of different stages or selection against the overlapping QTLs between the two stages via marker-assisted selection(MAS).ZANG JinPing 1 ,SUN Yong 1 ,WANG Yun 1 ,YANG Jing 1 ,LI Fang 1 ,ZHOU YongLi 1 ,ZHU LingHua 1 , Reys JESSICA2,Fotokian MOHAMMADHOSEIN 2,XU JianLong 1&LI ZhiKang 1,2 1Institute of Crop Sciences/National Key Facility for Crop Gene Resources&Genetic Improvement,Chinese Academy of Agricul- tural Sciences,Beijing 100081,China 2International Rice Research Institute,DAPO Box 7777,Metro Manila,Philippines 2008Science China(Life Sciences)2008,51,7:32
10Energy analysis for damage and catastrophic failure of rocks显示文摘The development history and current state of studies on the characteristics and mechanisms of deformation and failure of rock materials were briefly reviewed from the viewpoint of energy.The main scope and the achievable objectives of the energy-based research system were expatiated.It was validated by experiments that the damage process of rocks can be well described by the rock damage evolution equation established based on energy dissipation.It was found from the uniaxial compression and biaxial compression tests that only a small proportion of the total input energy in hard rocks is dissipated before peak load and a large proportion in soft rocks is dissipated before peak load.For both hard and soft rocks,the energy dissipated after peak load accounts for a greater proportion.More energy would be required for rock failure under equal biaxial compression than under unequal biaxial compression.The total absorbed energy is different for rock failure under high-rate loading and low-rate loading.More fragmented failure pattern usually corresponds to higher energy absorption.The mesoscopic analysis on the damage and failure of bedded salt rocks showed that the energy dissipation is prominent and the total absorbed energy for rock failure is low when cracks propagate in the weak mud interlayer while it is contrary when cracks propagate in the salt rock.The energy accumulation,transfer,dissipation and release during the failure process of tunnel with impending failure under disturbance were analyzed theoretically based on the elastoplastic mechanics theory.Furthermore,the spatial distribution of energy dissipation and energy release of fractured rocks under unloading was simulated numerically.It was demonstrated that energy is likely to be released from the weakest surface under compression,which triggers the global failure of rocks.XIE HePing 1,2,LI LiYun 2,1,JU Yang 2,PENG RuiDong 2 & YANG YongMing 2 1 Sichuan University,Chengdu 610065,China 2 State Key Laboratory of Coal Resources and Safe Mining,Beijing Key Laboratory of Fracture and Damage Mechanics of Rock and Concrete,China University of Mining and Technology,Beijing 100083,China 2011Science China(Technological Sciences)2011,54,S1:29
11Epigenetic regulation: methylation of histone and non-histone proteins显示文摘Histone methylation is believed to play important roles in epigenetic memory in various biological processes. However, questions like whether the methylation marks themselves are faithfully transmit- ted into daughter cells and through what mechanisms are currently under active investigation. Previ- ously, methylation was considered to be irreversible, but the recent discovery of histone lysine de- methylases revealed a dynamic nature of histone methylation regulation on four of the main sites of methylation on histone H3 and H4 tails (H3K4, H3K9, H3K27 and H3K36). Even so, it is still unclear whether demethylases specific for the remaining two sites, H3K79 and H4K20, exist. Furthermore, be- sides histone proteins, the lysine methylation and demethylation also occur on non-histone proteins, which are probably subjected to similar regulation as histones. This review discusses recent pro- gresses in protein lysine methylation regulation focusing on the above topics, while referring readers to a number of recent reviews for the biochemistry and biology of these enzymes.LAN Fei1 & SHI Yang 2 1 Department of Biology, Constellation Pharmaceuticals, 148 Sidney Street, Cambridge, MA 02139, USA 2 Department of Pathology, Harvard Medical School, 77 Ave Louise Pasteur, Boston MA, 02115, USA 2009Science China(Life Sciences)2009,52,4:27
12Indian monsoon influences altitude effect of δ^(18)O in precipitation/river water on the Tibetan Plateau显示文摘The δ 18O variation in precipitation acquired from 28 stations within the network of Tibetan Observation and Research Platform(TORP)is studied, with the focus on the altitude effect of δ 18O in river water during monsoon precipitation in an effort to understand the monsoon influence on isotopic composition in annual river water. It is found that δ 18O in precipitation on the Plateau is influenced by different moisture sources, with significant Indian monsoon influence on δ 18O composition in plateau precipitation and river water. The δ 18O of water bodies in the monsoon domain is generally more depleted than that in the westerly domain, suggesting gradual rainout of southwesterly borne marine moisture in the course of long-distance transportation and lifting over the Himalayas. The lapse rate of δ 18O in river water with altitude is the largest during monsoon precipitation, due to the increased temperature vertical gradient over the southern Plateau region controlled by monsoon circulation. The combination of δ 18O in river water in monsoon (wet) and non-monsoon (dry) seasons shows a larger lapse rate than that in non-monsoon (dry) season alone. As the altitude effect of δ 18O in precipitation and river water on the Tibetan Plateau results from the combined effect of monsoon moisture supply and westerly moisture supply, the δ 18O composition and its altitude effect on the Plateau during monsoon seasons should be considered in the reconstruction of paleoelevation of the Tibetan Plateau.YAO TanDong1,2, ZHOU Hang1,3 & YANG XiaoXin1,3 1 Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China 2 State Key Laboratory of Cryosphere Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China 3 Graduate University of Chinese Academy of Sciences, Beijing 100049, China 2009Chinese Science Bulletin2009,54,16:28
13Ability of Agrogyron elongatum to accumulate the single metal of cadmium, copper, nickel and lead and root exudation of organic acids显示文摘Agrogyron elongatum were grown in nutrient solution containing moderate to high amounts of separate heavy metal of Cd, Cu, Ni and Pb in a greenhouse for a 9-day. Cd, Cu, Ni and Pb generally led to decrease in the elongation of roots although the length of seedlings exposed to Cd and Pb at 0.05 and 0 5 mg/L showed to be slightly greater than that of controls. Of the four metals in the experiment, Pb was absorbed and accumulated to the highest level, with the concentrations of 92754 mg/kg dry weight (DW) in roots and 11683 mg/kg DW in shoots. Cd was moderately accumulated in Agrogyron elongatum, but the maximum bioaccumulation coefficients (BCs) for roots and shoots were observed. The patterns for Cu and Ni uptake and distribution in plants differed from those of Pb and Cd, as it was showed that the shoot accumulation of Cu and Ni was significantly higher than in roots. A. elongatum had the highest Ni concentration in shoots (30261 mg/kg DW) at the external concentration of 250 mg/L. Cu ranked second, with a shoot concentration of 12230 mg/kg DW when 50 mg/L Cu in solution was applied. For the four trace elements tested, the highest concentrations in shoots decreased by the order of Ni>Cu>Pb>Cd (mg/kg DW), and those in roots were Pb>Cd>Ni>Cu (mg/kg DW). Malic, oxalic and citric acids exuded by roots exposed to 1 and 50 mg/L of the metals were detected. Release of organic acids from plants significantly differed among the metal treatments. Cu was most effectively in inducing root exudation of the three types of organic acids. Cd, and Ni were also the inducers of secretion of malic and oxalic acids. With reference of Pb, a small amounts of malic and oxalic acids were detected in the root exudates, but few quantities of citric acid were found. However, no correlation between alternations in root exudation of organic acids and metal accumulation could be established.YANG Hong 1, Jongathan W.C.Wong 2, YANG Zhi min\+1, ZHOU Li xiang 1(1. College of Science, Nanjing Agricultural University, Nanjing\ 210095, China. 2. Department of Biology, Hong Kong Baptist University, China) 2001Journal of Environmental Sciences2001,13,3:26
14Discovery of a Late Permian Angara-Cathaysia mixed flora from Acheng of Heilongjiang,China,with discussions on the closure of the Paleoasian Ocean显示文摘This work documents a new flora from the Upper Permian Hongshan Formation of Acheng County, Heilongjiang Province, Northwest China. The flora consists of 20 species: Paracalamites sp., Pecopteris tangwangheensis Huang, Callipteris obese Huang, Callipteris shenshuensis Huang, C. tangwangheensis Huang, C. heilongjiangensis Huang, C. zeilleri Zalessky, C. sp., Comia yichunensis Huang, C. tenueaxis Huang, Iniopteris sibirica Zalessky, Supaia teiliensis Huang, Compsopteris tchirkovae Zalessky, C. cf. adzvensis Zalessky, Nilssonia sp. 1, Nil. sp. 2, Taeniopteris cf. densissima Halle, T. cf. nystraemii Halle, T. sp. and Noeggerathiopsis derzavinii Neub. It is dominated by Angara species but mixed with some typical Cathaysian elements. The age of the flora is assigned to late of the Late Permian according to the stratigraphic ranges of the known species and the comparisons of it with the similar floras. The new discovery indicates that the final collision between the North China Plate and Siberian Plate occurred in Late Permian along the Xar Moron River-Changchun-Yanji sutured zone, and the Paleoasian Ocean was finally closed at the end of the Permian.DENG ShengHui1,2, WAN ChuanBiao3 & YANG JianGuo3 1 Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China 2 State Key Laboratory of Enhanced Oil Recovery, Beijing 100083 China 3 Daqing Institute of Petroleum Exploration and Development, PetroChina, Daqing 164712, China 2009Science China Earth Sciences2009,52,11:22
15Strong law of large numbers for Markov chains indexed by an infinite tree with uniformly bounded degree显示文摘In this paper,we study the strong law of large numbers and Shannon-McMillan (S-M) theorem for Markov chains indexed by an infinite tree with uniformly bounded degree.The results generalize the analogous results on a homogeneous tree.HUANG HuiLin~1 YANG WeiGuo~(2+) 1 Department of Mathematics,Shanghai Jiaotong University,Shanghai 200240,China 2 Faculty of Science,Jiangsu University,Zhenjiang 212013,China 2008Science China Mathematics2008,51,2:23
16A 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
17Expression of insulin-like growth factor Ⅱ and its receptor in liver cells of chronic liver diseases显示文摘ExpressionofinsulinlikegrowthfactorⅡanditsreceptorinlivercelsofchronicliverdiseasesYANGDongHua1,XIUChong1,YANGBo1,GUJianR...YANG Dong Hua 1, XIU Chong 1, YANG Bo 1, GU Jian Ren 2, QIAN Lian Fang 2 and QU Shu Ming 2 1997World Journal of Gastroenterology1997,3,2:21
18Geochronology of middle Neoproterozoic volcanic deposits in Yangtze Craton interior of South China and its implications to tectonic settings显示文摘Here we report new SHRIMP dating results of the crystal tuff in Ejiaao Formation of middle Banxi Group in northern Guizhou. The results indicate that the volcanic deposition occurred at ~780 Ma. We also suggests that the igneous activities across Yangtze Craton with diabase dyke swarms and basal volcanic rocks during middle Banxi time are indicative of the episodic, extensive and vigorous great bimodal igneous events during middle Neoproterozoic (825-720 Ma) in South China. The characteristics of the igneous series are contrary to the model claiming they are of island-arc origin, but suggest that they are the records of rifting process and may be related to the episodic plume activities leading to the break-up of Rodinia.WANG ZhengJiang1, WANG Jian1, DUAN TaiZhong2, XIE Yuan1, ZHUO JieWen1,3 & YANG Ping1 1 Chengdu Institute of Geology and Mineral Resources, Ministry of Land and Resources, Chengdu 610082, China 2 Marathon Oil UK Ltd., Aberdeen, Scotland, AB15 6FZ, UK 3 Graduate Department, Chinese Academy of Geological Sciences, Beijing 100037, China 2010Science China Earth Sciences2010,53,9:20
19Quantum 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
20The use of laser ranging to measure space debris显示文摘Space debris is a major problem for all the nations that are currently active in space.Adopting high-precision measuring techniques will help produce a reliable and accurate catalog for space debris and collision avoidance.Laser ranging is a kind of real-time measuring technology with high precision for space debris observation.The first space-debris laser-ranging experiment in China was performed at the Shanghai Observatory in July 2008 with a ranging precision of about 60-80 cm.The experimental results showed that the return signals from the targets with a range of 900 km were quite strong,with a power of 40W (2J at 20 Hz) using a 10ns pulse width laser at 532 nm wavelength.The performance of the preliminary laser ranging system and the observed results in 2008 and 2010 are also introduced.Zhong-Ping Zhang 1,2,Fu-Min Yang 1,Hai-Feng Zhang 1,Zhi-Bo Wu 1,2,Ju-Ping Chen 1,2,Pu Li 1 and Wen-Dong Meng 1 1 Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030,China 2 Key Laboratory of Space Object and Debris Observation,Chinese Academy of Science,Nanjing 210008,China 2012Research in Astronomy and Astrophysics2012,12,2:20
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