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| 1 | Impacts of permafrost changes on alpine ecosystem in Qinghai-Tibet Plateau显示文摘Alpine cold ecosystem with permafrost environment is quite sensitive to climatic changes and the changes in permafrost can significantly affect the alpine ecosystem. The vegetation coverage, grassland biomass and soil nutrient and texture are selected to indicate the regime of alpine cold ecosystems in the Qinghai-Tibet Plateau. The interactions between alpine ecosystem and permafrost were investigated with the depth of active layer, permafrost thickness and mean annual ground temperature (MAGTs). Based on the statistics model of GPTR for MAGTs and annual air temperatures, an analysis method was developed to analyze the impacts of permafrost changes on the alpine ecosystems. Under the climate change and human engineering activities, the permafrost change and its impacts on alpine ecosystems in the permafrost region between the Kunlun Mountains and the Tanggula Range of Qinghai-Tibet Plateau are studied in this paper. The results showed that the per- mafrost changes have a different influence on different alpine ecosystems. With the increase in the thickness of active layer, the vegetation cover and biomass of the alpine cold meadow exhibit a significant conic reduction, the soil organic matter content of the alpine cold meadow ecosystem shows an exponential decrease, and the surface soil materials become coarse and gravelly. The alpine cold steppe ecosystem, however, seems to have a relatively weak relation to the permafrost environment. Those relationships resulted in the fact that the distribution area of alpine cold meadow decreased by 7.98% and alpine cold swamp decreased by 28.11% under the permafrost environment degradation during recent 15 years. In the future 50 years the alpine cold meadow ecosystems in different geomorphologic units may have different responses to the changes of the permafrost under different climate warming conditions, among them the alpine cold meadow and swamp ecosystem located in the low mountain and plateau area will have a relatively serious degradation. Furthermore, from the angles of grassland coverage and biological production the variation characteristics of high-cold eco- systems in different representative regions and different geomorphologic units under different climatic conditions were quantitatively assessed. In the future, adopting effective measures to protect permafrost is of vital importance to maintaining the stability of permafrost engineering and alpine cold eco- systems in the plateau. | WANG Genxu1,3 , LI Yuanshou2 , WU Qingbai2 & WANG Yibo3 1. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China 2. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China 3. Resource and Environment School, Lanzhou University, Lanzhou 730000, China | 2006 | Science China Earth Sciences2006,49,11: | 41 |
| 2 | Phase I study of chimeric antigen receptor modified T cells in treating HER2-positive advanced biliary tract cancers and pancreatic cancers显示文摘 | Kaichao Feng Yang Liu Yelei Guo Jingdan Qiu Zhiqiang Wu Hanren Dai Qingming Yang Yao Wang Weidong Han1,3 | 2018 | Protein & Cell2018,9,10: | 37 |
| 3 | Hyaluronic acid fragments evoke Kupffer cells via TLR4 signaling pathway显示文摘Kupffer cells, expressing toll-like receptor 4 (TLR4), play a central role in hepatic ischemia/reperfusion (I/R) injury. Hyaluronic acid (HA) fragments, degradative products of high-molecular-weight HA (HMW-HA), acquire the ability to activate immune cells under inflammatory conditions. Here we inves- tigated whether HA fragments could activate Kupffer cells and analyzed the underlying mechanism. Kupffer cells were isolated from wild-type mice (WT, C3H/HeN) and TLR4 mutant mice (C3H/HeJ) and HA fragments were produced by the methods of enzyme digestion and chromatography. Then Kupffer cells were stimulated by HA fragments or other control stimuli. The activation of Kupffer cells was estimated as the release of pro-inflammatory cytokines. The activation of p38 MAPK pathway of Kupffer cells was checked and blocking experiments were done as well. The results indicated that HA fragments acquired the ability to activate Kupffer cells in vitro, which was TLR4 dependent and not due to contamination of lipopolysaccharide. Experiments of p38 MAPK kinase inhibition by SB-203580 verified p38 MAPK was required in HA fragments induced Kupffer cells activation. This suggests that HA fragments, degradative products of one of the major glycosaminoglycans of the extracellular matrix, play critical roles in Kupffer cell activation mediated by TLR4 signaling pathway, which is, at least partially, de- pendent on p38 MAPK activation. | ZHANG JinXiang1, WANG Hui2, XIAO Qing3, LIANG HuiFang4, LI ZhuoYa4, JIANG ChunFang1, WU HeShui5 & ZHENG QiChang5 1 Department of Emergency Surgery, Union Hospital Affiliated to Huazhong University of Science and Technology, Wuhan 430022, China 2 Department of Medical Genetics, Tongji Medical College Affiliated to Huazhong University of Science and Technology, Wuhan 430030, China 3 Department of Ophthalmology, Union Hospital Affiliated to Huazhong University of Science and Technology, Wuhan 430022, China 4 Department of Medical Immunology, Tongji Medical College Affiliated to Huazhong University of Science and Technology, Wuhan 430030, China 5 Department of General Surgery, Union Hospital Affiliated to Huazhong University of Science and Technology, Wuhan 430022, China | 2009 | Science China(Life Sciences)2009,52,2: | 33 |
| 4 | Mechanism of the Spring Persistent Rains over southeastern China显示文摘The Spring Persistent Rains (SPR) in the areas to the south of middle and lower reaches of the Yangtze River or over southeastern China (SEC) is a unique synoptic and climatic phenomenon in East Asia. This study reveals a possible mechanism responsible for the climatic cause of SPR formation through climatic mean data analysis and sensitive numerical model experiments. SEC is located at the down-stream of the southwesterly velocity center (SWVC) which lies on the southeastern flank of the Tibetan Plateau (TP). As a result, there are strong southwesterly wind velocity convergence and moisture con-vergence over SEC. This is the immediate climatic cause of SPR formation. In spring, the seasonal evolution of the southwesterly velocity consists with the surface sensible heating over southeastern TP, indicating that the formation of SPR is related to not only the southwesterly wind of mechanical de-flected flow of TP, but also the southwesterly wind of thermal-forced cyclonic low circulation. Sensitive numerical experiments demonstrate that, without TP, both SWVC and the SPR rain belt will disappear. The southwesterly wind velocity increases almost linearly with the amount of the total diabatic heating with TP rising. Therefore, SWVC is the result of the mechanical forcing and thermal forcing of TP. All these strongly suggest that the presence of TP plays a primary role in the climatic formation of SPR. | WAN RiJin1,2,3 & WU GuoXiong1 1 State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Mechanicals (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China 2 Guangdong Climate and Agrometeorology Center, Guangzhou 510080, China 3 Shanghai Typhoon Institute of China Meterological Administration, Shanghai 200030, China | 2007 | Science China Earth Sciences2007,50,1: | 34 |
| 5 | Genetic analysis and gene mapping of a new rolled-leaf mutant in rice (Oryza sativa L.)显示文摘To understand the development of rice leaf blades,we identified a new rolled-leaf mutant,w32,from indica cultivar IR64 through EMS mutagenesis. The mutant showed a stable rolled-leaf phenotype throughout the life cycle. Two F2 populations were developed by crossing w32 to cultivar IR24 and PA64. Genetic analysis showed that the rolled-leaf phenotype was controlled by a single recessive gene. To determine the location of the gene,bulked segregant analysis was carried out using mutant and wild-type DNA pools and 1846 mutant-type F2 individuals derived from the cross w32/PA64 were genotyped to locate the gene on the short arm of chromosome 7. The rolled-leaf gene,tentatively named rl11(t),is likely a new gene as no other rolled-leaf genes have been identified near the region. By developing new SSR and InDel markers,the gene was delimited to a 52 kb region near the end of the short chromosome arm. Further fine mapping and cloning of the gene are currently underway. | SHI YongFeng1,2,CHEN Jie1,LIU WenQiang1,HUANG QiNa1,2,SHEN Bo2,LEUNG Hei3 & WU JianLi1 1 Chinese National Center for Rice Improvement/National key Laboratory for Rice Biology,China National Rice Research Institute,Hangzhou 310006,China 2 College of Life and Environmental Sciences,Hangzhou Normal University,Hangzhou 310016,China 3 International Rice Research Institute,Metro Manila DAPO Box 7777,Philippines | 2009 | Science China(Life Sciences)2009,52,9: | 29 |
| 6 | Production of proinflammatory cytokines in the human THP-1 monocyte cell line following induction by Tp0751,a recombinant protein of Treponema pallidum显示文摘The tissue destruction characteristic of syphilis infection may be caused by inflammation due to Treponema pallidum and the ensuing immune responses to the pathogen.T.pallidum membrane proteins are thought to be potent inducers of inflammation during the early stages of infection.However,the actual membrane proteins that induce inflammatory cytokine production are not known,nor are the molecular mechanisms responsible for triggering and sustaining the inflammatory cascades.In the present study,Tp0751 recombinant protein from T.pallidum was found to induce the production of proinflammatory cytokines,including TNF-α,IL-1βand IL-6,in a THP-1 human monocyte cell line.The signal transduction pathways involved in the production of these cytokines were then further investigated.No inhibition of TNF-a,IL-1β,or IL-6 production was observed following treatment with the SAPK/JNK specific inhibitor SP600125 or with an ERK inhibitor PD98059.By contrast,anti-TLR2 mAb,anti-CD14 mAb,and the p38 inhibitor SB203580 significantly inhibited the production of all three cytokines.In addition,pyrrolidine dithiocarbamate (PDTC),a specific inhibitor of NF-κB,profoundly inhibited the production of these cytokines.Tp0751 treatment strongly activated NF-κB,as revealed by Western blotting.However,NF-κB translocation was significantly inhibited by treatment with PDTC.These results indicated that TLR2,CD14,MAPKs/p38,and NF-κB might be implicated in the inflammatory reaction caused by T.pallidum infection. | LIU ShuangQuan1,2,WANG ShiPing1,WU YiMou3,ZHAO FeiJun3,ZENG TieBing3,ZHANG YueJun3,ZHANG QiuGui2 & GAO DongMei1 1 Department of Parasitology,Xiangya School of Medicine,Central South University,Changsha 410078 ,China 2 The First Affiliated Hospital,University of South China,Hengyan 421001,China 3 Department of Microbiology and Immunology,University of South China,Hengyan 421001,China | 2010 | Science China(Life Sciences)2010,53,2: | 28 |
| 7 | Deficit of mitochondria-derived ATP during oxidative stress impairs mouse MII oocyte spindles显示文摘尽管在母亲的老化和不孕的氧化应力的角色被建议了,内在的机制充分没被理解。现在的学习被设计在氧化应力下面在中期 II (MII ) 卵母细胞决定在 mitochondrial 功能和锭子稳定性之间的关系。MII 老鼠卵母细胞当面与 H2O2 被对待或渗透转变毛孔(PTP ) 的缺席块 ers cyclosporin A (CsA ) 。另外,抗氧化剂 N-acetylcysteine (NAC ) , F0/F1 synthase 禁止者 oligomycin A,线粒体 uncoupler 羰基氰化物 4-trifluoro-methoxyphenylhydrazone (FCCP ) 或加 2.5 公里 Ca2+(Th+2.5 公里 Ca2+) 的 thapsigargin 在机械学的研究被使用。卵母细胞锭子和染色体的词法分析被执行并且 mitochondrial 膜潜力(DeltaPsim ) ,细胞质的免费的钙集中([Ca2+] c ) 并且在卵母细胞以内的细胞质的 ATP 内容也是 assayed。在一时间 -- 并且 H2O2 剂量依赖者举止,锭子在卵母细胞以后被发现的 meiotic 的混乱与 H2O2 被对待,它被预告的处理与 NAC 阻止。H2O2 的管理导致了 DeltaPsim 的驱散,的增加[Ca2+] 在细胞质的 ATP 的 c 和减少铺平。到 H2O2 处理的卵母细胞的这些有害回答能被孵化前与 CsA 堵住。类似于驱散的 H2O2,两 oligomycin A 和 FCCP DeltaPsim,减少的细胞质的 ATP 内容和拆卸的 MII 卵母细胞锭子,当时高[Ca2+] c 独自没在锭子形态学上有效果。在结论,在导出线粒体的 ATP 的减少可以在氧化应力期间引起老鼠 MII 卵母细胞锭子的拆卸,大概由于 mitochondrial PTP 的开始。 | Xiao Zhang~(1,2,*) Xue Qing Wu~(1,3,*) Shuang Lu~(4,5,6) Ying Lu Guo~1 Xu Ma~(4,5,6) ~1Peking University First Hospital,Institute of Urology of Peking University,Beijing 100034,China ~2Reproductive and Genetic Center of Peking University First Hospital,Beijing 100034,China ~3Department of Obstetrics and Gynecology,Shanxi Medical University Second Hospital,Taiyuan 030000,China ~4Reproductive and Genetic Center of National Research Institute for Family Planning,Beijing 100038,China ~5Department of Genetics, Peking Union Medical College, Beijing 100038. China ~6 WHO Collaborative Center for Research in Human Reproduction,Beijing 100038,China | 2006 | Cell Research2006,16,10: | 24 |
| 8 | Reconstructing mean maximum temperature of growing season from the maximum density of the Schrenk Spruce in Yili,Xinjiang,China显示文摘To study the historical temperature variation in Yili of Xinjiang,the tree-ring chronologies of maximum density(MXD) and tree-ring width(TRW) were established with the Schrenk Spruce(Picea schrenkiana Fisch.et Mey) collected from six sites to analyze the characteristics and ability of response to climate change.The results suggest that the MXD chronology of the Schrenk Spruce from different sampling sites responded to climate change well and were positively correlated with the mean maximum temperature and the mean temperature from April to August in the study area.The mean maximum temperature anomaly from April to August,spanning the years from 1848 to 2000,was reconstructed by three MXD chronologies which were selected by stepwise regression.The reconstructed function was stable and explained 56.2% of the variance.The reconstructed results indicated a cold span of 153 years in spring and summer from the beginning of the 1950s to the beginning of the 1970s in the Yili valley.No strongly increasing tendency was detected in the mean maximum temperature anomaly from April to August during this reconstructed period. | CHEN Jin1,2,3,WANG LiLi1,4,5,ZHU HaiFeng1 & WU Pu1 1 Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China 2 Graduate University of Chinese Academy of Sciences,Beijing 100049,China 3 Institute of Vertebrate Paleontology and Paleoanthropology,Chinese Academy of Sciences,Beijing 100044,China 4 Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100085,China 5 Institute of Desert and Meteorology,China Meteorological Administration,ürümqi 830002,China | 2009 | Chinese Science Bulletin2009,54,13: | 21 |
| 9 | Orbit determination and prediction accuracy analysis for a regional tracking network显示文摘China's COMPASS satellite navigation system relies on a regional tracking network to provide navigation services. Limited by its geographic border,the regional network is able to cover only 30% of the medium-earth-orbits(MEO). Accuracy of determined and predicted orbits is not able to satisfy system requirements if the tracking data processing strategy for global tracking network processing is used for the regional network. Two major error sources for orbital prediction are accuracy of initial orbital elements and dynamical modeling. To achieve better prediction accuracy,we propose a two-step orbit determination and prediction strategy. For step 1,only solar radiation pressure(SRP) parameters are estimated along with the orbital elements and other parameters; for step 2,all parameters are estimated but the SRP parameters are tightly constrained to their step 1 estimates. Experimenting with data from a regional GPS network,we conclude for orbital prediction using the proposed two-step strategy,the average user range error(URE) for 24-h prediction arcs is better than 0.6 m. | ZHOU ShanShi 1,2,3 ,HU XiaoGong 1 & WU Bin 1 1 Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030,China 2 Graduate University of Chinese Academy of Sciences,Beijing 100049,China 3 Research Center of GNSS,Wuhan 430079,China | 2010 | Science China(Physics,Mechanics & Astronomy)2010,53,6: | 16 |
| 10 | Immunization with chlamydial plasmid protein pORF5 DNA vaccine induces protective immunity against genital chlamydial infection in mice显示文摘To validate the immune protective efficacy of pORF5 DNA vaccine and to analyze potential mechanisms related to this protection. In this study, pORF5 DNA vaccine was constructed and evaluated for its protective immunity in a mouse model of genital chlamydial infection. Groups of BALB/c mice were immunized intranasally with pORF5 DNA vaccine. Humoral and cell mediated immune responses were evaluated. The clearance ability of chlamydial challenge from the genital tract and the chlamy- dia-induced upper genital tract gross pathology and histopathological characterization were also de- tected. The results showed that the total and the IgG2a anti-pORF5 antibody levels in serum were sig- nificantly elevated after pcDNA3.1-pORF5 vaccination, as were the total antibody and IgA levels in vaginal fluids. pcDNA3.1-pORF5 induced a significantly high level of Th1 response as measured by robust gamma interferon (IFN-γ). Minimal IL-4 was produced by immune T cells in response to the re-stimulation with pORF5 protein or the inactive elementary body in vitro. pcDNA3.1-pORF5-vacci- nated mice displayed significantly reduced bacterial shedding upon a chlamydial challenge and an accelerated resolution of infection. 100% of pcDNA3.1-pORF5 vaccinated mice successfully resolved the infection by day 24. pcDNA3.1-pORF5-immunized mice also exhibited protection against patho- logical consequences of chlamydial infection. The stimulated index was significantly higher than that of mice immunized with pcDNA3.1 and PBS (P<0.05). Together, these results demonstrated that immu- nization with pORF5 DNA vaccine is a promising approach for eliciting a protective immunity against a genital chlamydial challenge. | LI ZhongYu1,2, WANG ShiPing1, Wu YiMou2, ZHONG GuangMing3 & CHEN Ding3 1 Xiangya School of Medicine, Central South University, Changsha 410078, China 2 Department of Microbiology and Immunology, University of South China, Hengyang 421001, China 3 University of Texas Health Science Center at San Antonio, TX 78229, USA | 2008 | Science China(Life Sciences)2008,51,11: | 16 |
| 11 | Discovery and character of the Kunlun-Yellow River Movement显示文摘Based on geomorphological, tectonic and sedimentary data, a Kunlun Yellow River Tectonic Movement has been recognized in 1 10-0 60 Ma B.P. This tectonic movement, which leads to uplift of the Qinghai_Xizang (Tibet) Plateau from 1 500 to 3 000-3 500 m, is periodic, abrupt and changeable in the movement rate of uplifting and slide slipping. | CUI Zhijiu 1, WU Yongqiu 2,3 and LIU Gengnian 1 1. Department of Geography, Peking University, Beijing 100871, China 2. Open Research Laboratory of Environmental Changes and Natural Disaster of State Education Commission, Beijing 100875, China | 1998 | Chinese Science Bulletin1998,43,10: | 16 |
| 12 | Carbon isotope ratios of C_(4) plants in loess areas of North China显示文摘Carbon isotope ratios (δ 13C) of 89 C4 plant samples were determined from the loess area in North China. δ 13C values vary between –10.5‰ and –14.6‰ with a mean of –12.6‰. Along a pre-cipitation gradient from the semi-moist area to the semiarid area, then to the arid area, the δ 13C val-ues of C4 plants show a slight decreasing trend. The δ 13C values of C4 plants in the dry season are found lower than those in the wet season. These trends are opposite to those observed for C3 spe-cies. | WANG Guoan1,2,3, HAN Jiamao 2, ZHOU Liping3, XIONG Xiaogang4, TAN Ming2, WU Zhenhai5 & PENG Jun6 1. Department of Plant Nutrition, China Agricultural University, Beijing 100094, China 2. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 3. College of Environmental Sciences, MOE Laboratory for Earth Surface Processes, Peking University, Beijing 100871, China 4. Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China 5. Northwest Sci-Tech University of Agriculture and Forestry, Yangling 712100, China 6. Network Center, China Agricultural University, Beijing 100094, China | 2006 | Science China Earth Sciences2006,49,1: | 16 |
| 13 | Rb1 protects endothelial cells from hydrogen peroxide-induced cell senescence by modulating redox status显示文摘Objectives Endothelial senescence has been proposed to be involved in endothelial dysfunction and atherogenesis. This study investigates the effects of ginsenoside Rbl, a major constituent of ginseng,on H2O2-induced endothelial senescence.Methods Primary human umbilical vein endothelial cells(HUVECs) senescence was induced by H2O2 as judged by senescence-associated P-galactosidase assay (SA-P-gal).Fntracellur superoxide dismutase(S0D1) activity and malondialdehyde(MDA) level were determined by commercial kit.S0D1 mRNA and protein expression were analyzed by real time PCR and Western blot.Reactive oxygen species(ROS) were determined by flow cytometry.Results Rb1 was found to reverse endothelial senescence,as witnessed by a significant decrease of senescent cell numbers. Rbl could markedly increase intracellular SOD activity, decrease the MDA level,and suppress the generation of intracellular ROS in H2O2-treated HUVECs.Consistent with these findings,Rbl can effectively restore SOD1 mRNA and protein expression which decreased in H2O2 treated cells. Conclusions Our report demonstrates thatRbl can exert reversal effects on H2O2-induced cellular senescence through modulating cellular redox status. | LIU Ding-hui~1,CHEN Yan-ming~2,LIU Yong~1,HAO Bao-shun~1, ZHOU Bin~1,WU Lin~1,WANG Min~1,CHEN Lin~1,WU Wei-kang~3,QIAN Xiao-xian~1 (1.Department of Cardiology,The Third Affiliated Hospital of Sun Yat-sen University,Guagnzhou 510630 2.Department of Endocrinology,The Third Affiliated Hospital of Sun Yat-sen, Guagnzhou 510630 3.Institute Integrated Traditional Chinese and Western Medicine,Sun Yat-sen University,Guagnzhou 510630) | 2011 | 岭南心血管病杂志2011,17,S1: | 15 |
| 14 | Modeling and verifying Web services driven by requirements:An ontology-based approach显示文摘Automatic discovery and composition of Web services is an important research area in Web service technology, in which the specification of Web services is a key issue. This paper presents a Web service capability description framework based on the environment ontology. This framework depicts Web services capability in two aspects: the operable environment and the environment changes resulting from behaviors of the Web service. On the basis of the framework, a requirement-driven Web service composition model has been constructed. This paper brings forward the formalization of Web service interactions with π calculus. And an automatic mechanism converting conceptual capability description to the formal process expression has been built. This kind of formal specification assists in verifying whether the composite Web service model matches the requirement. | HOU Lishan1,3,JIN ZHi1,2 & WU Budan1,4 1. Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100080, China 2. Institute of Computing Technology, Chinese Academy of Sciences, Beijing 100080, China 3. Institute of Software, Chinese Academy of Sciences, Beijing 100080, China 4. Graduate University of Chinese Academy of Sciences, Beijing 100049, China | 2006 | Science in China(Series F)2006,49,6: | 15 |
| 15 | Hierarchy modeling of subsurface palaeochannel reservoir architecture显示文摘The studies on fluvial reservoir architecture are mainly aimed at outcrop and modern deposition,but rarely at the subsurface reservoir,so there are few effective methods to predict the distribution of subsurface reservoir architectures. In this paper,taking the meandering river reservoir of Guantao formation Gudao Oilfield,Jiyang depression,Baohai Gulf Basin,East China as an example,the archi-tectural modeling method of complex meandering belt reservoir is proposed,that is hierarchy con-straint,pattern fitting and multi-dimensional interaction. Architectures of meandering river reservoir can be divided into three hierarchies: meandering channel sandbody,point bar and lateral accretion body. Different hierarchies of the quantitative architecture pattern are fitted to subsurface well data (including dynamic monitoring data) in different hierarchies through one-dimensional hole,2D profiles and plane and 3D space,which are verified by each other. And then 3D model in different hierarchies is established. At the same time,the quantificational relationship between width of active river and the scale of point bar is set up,and the scale of lateral accretion sand body and shale beddings is con-firmed with horizontal well data. The study not only has significant meaning on the development of geology,but also can improve the oilfield exploitation greatly. | WU ShengHe1,YUE DaLi1,LIU JianMin2,SHU QingLin2,FAN Zheng1,3 & LI YuPeng1 1 Earth Sciences and Geoinformatics School,China University of Petroleum,Beijing 102249,China 2 SINOPEC Shengli Oilfield Co. Ltd.,Dongying 257000,China 3 Beijing Telon High-tech Corporation,Beijing 100085,China | 2008 | Science China Earth Sciences2008,51,S2: | 15 |
| 16 | Quantitative analysis of soil pores under natural vegetation successions on the Loess Plateau显示文摘Soil pore is a key attribute of the soil structure that affects soil reservoir under natural vegetation recovery on the Loess Plateau.This study is to quantitatively analyze soil pore parameters,measured with Computed Tomography(CT) at 15-57 mm depths under five different vegetation succession stages using a concept of substituting 'space' for 'time' in the Ziwuling Forest Region of the Loess Plateau.The results showed that the soil pore parameters,such as pore number,porosity,circularity,and fractal dimension,increased significantly under the natural vegetation successions and varied with the pattern climax community stage>pioneering arbor community stage>scrub community stage>herbaceous community stage>abandoned farmland stage,indicating that natural vegetation recovery could remarkably improve soil pore characteristics.With the vegetation succession,this positive effect will be strengthened gradually,which means that the soil pore parameters may appear to be best at the climax community stage.Soil organic matter content increased linearly with the soil pore parameters(P<0.001).Increased organic matter accumulation was one of the major reasons for the changes in soil pore characteristics in natural vegetation succession. | ZHAO ShiWei1,ZHAO YongGang1,2 & WU JinShui3 1 State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Northwest Agriculture & Forestry University,Yangling 712100,China 2 Graduate University of Chinese Academy of Sciences,Beijing 100049,China 3 Institute of Subtropical Agriculture,Chinese Academy of Sciences,Changsha 410125,China | 2010 | Science China Earth Sciences2010,53,4: | 14 |
| 17 | Orbit determination for geostationary satellites with the combination of transfer ranging and pseudorange data显示文摘Geostationary satellites(GEOs) play a significant role in the regional satellite navigation system.Simulation experiments show that the clock corrections could be mitigated through a single strategy or double differencing strategies for a navigation constellation,but for the mode of individual GEO orbit determination,high precision orbit and clock correction could not be obtained in the orbit determination based on the pseudorange data.A new GEO combined precise orbit determination(POD) strategy is studied in this paper,which combines pseudorange data and C-band transfer ranging data.This strategy overcomes the deficiency of C-band transfer ranging caused by limited stations and tracking time available.With the combination of transfer ranging and pseudorange data,clock corrections between the GEO and the stations can be estimated simultaneously along with orbital parameters,maintaining self-consistency between the satellite ephemeris and clock correction parameters.The error covariance analysis is conducted to illuminate the contributions from the transfer ranging data and the psudoranging data.Using data collected for a Chinese GEO satellite with 3 C-band transfer ranging stations and 4 L-band pseudorange tracking stations,POD experiments indicate that a meter-level accuracy is achievable.The root-mean-square(RMS) of the post-fit C-band ranging data is about 0.203 m,and the RMS of the post-fit pseudorange is 0.408 m.Radial component errors of the POD experiments are independently evaluated with the satellite laser ranging(SLR) data from a station in Beijing,with the residual RMS of 0.076 m.The SLR evaluation also suggests that for 2-h orbital predication,the predicted radial error is about 0.404 m,and the clock correction error is about 1.38 ns.Even for the combination of one C-band transfer ranging station and 4 pseudorange stations,POD is able to achieve a reasonable accuracy with the radial error of 0.280 m and the 2-h predicted radial error of 0.888 m.Clock synchronization between the GEO and tracking stations is achieved with an estimated accuracy of about 1.55 ns,meeting the navigation service requirements. | GUO Rui1,2,3,4,HU XiaoGong2,4,LIU Li1,WU XiaoLi1,HUANG Yong2,4 & HE Feng1 1 Beijing Global Information Application and Development Center,Beijing 100094,China 2 Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030,China 3 Graduate University of Chinese Academy of Sciences,Beijing 100049,China 4 Space Navigation and Positioning Technology,Laboratory of Shanghai Municipal,Shanghai 200030,China | 2010 | Science China(Physics,Mechanics & Astronomy)2010,53,9: | 13 |
| 18 | In situ experiments on width and evolution characteristics of excavation damaged zone in deeply buried tunnels显示文摘The seven long tunnels of Jinping II hydropower station are deeply buried.The width and evolution characteristics of excavation damaged zone(EDZ) are the key problem to the design of tunnels excavation and supports.In order to study this problem,several specific experimental tunnels with different overburden and geometric sizes were excavated at this site.Digital borehole camera,sliding micrometer,cross-hole acoustic wave equipment and acoustic emission apparatus were adopted.This paper introduced the comprehensive in situ experimental methods through pre-installed facilities and pre-drilled boreholes.Typical properties of the surrounding rock mass,including cracks,deformation,elastic wave and micro fractures,were measured during the whole process of the tunnel excavation.The width and characteristics of formation and evolution of tunnels EDZ were analyzed under different construction methods involving of TBM and drilling and blasting,the test tunnels were excavated by full-face or two benches.The relationships between EDZ and tunnel geometry sizes,overburden and excavation method were described as well.The results will not only contribute a great deal to the analysis of rock mass behavior in deeply buried rock mass,but also provide direct data for support design and rockburst prediction. | LI ShaoJun 1,FENG XiaTing 1,LI ZhanHai 3,CHEN BingRui 1,JIANG Quan 1,WU ShiYong 2,HU Bin 2 &XU JinSong 2 1 State Key Laboratory of Geomechanics and Geotechinical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China 2 Ertan Hydropower Development Company,Ltd.,Chengdu 610051,China 3 School of Resources and Civil Engineering,Northeastern University,Shenyang 110004,China | 2011 | Science China(Technological Sciences)2011,54,S1: | 13 |
| 19 | Adsorption properties of nitrobenzene in wastewater with silica aerogels显示文摘The adsorption properties of nitrobenzene from wastewater by hydrophobic silica aerogels were investigated.The effects of adsorption intensity by pH value,adsorption temperature,adsorption time and the amount of the silica aerogels were studied.The adsorption principle and mechanism of silica aerogels adsorbing nitrobenzene were discussed along with the Freundlich equation.The results showed that the adsorption intensity of the hydrophobic silica aerogels could reach 68.76% at better adsorption conditions of adsorption temperature 25°C,pH value 8.35,the amount of SiO2 aerogels dosage 3.33 g/L,and adsorption time of 30 min,and that the adsorption properties were related to the hydrophobility of aerogels,surface area of organic solution,structure of aerogels. | CUI Sheng1,LIU XueYong2,LIU Yu2,SHEN XiaoDong1,LIN BenLan1,3,HAN GuiFang1 & WU ZhanWu1 1 College of Material Science and Engineering,Nanjing University of Technology,Nanjing 210009,China 2 Institute of Chemical Materials,CAEP,Mianyang 621900,China 3 Editorial Board of Journal,Nanjing University of Technology,Nanjing 210009,China | 2010 | Science China(Technological Sciences)2010,53,9: | 13 |
| 20 | Research on Methods of Ecological Security Assessment of the Middle and Lower Reaches of Liaohe River Based on GIS显示文摘Ecological security assessment and early warning research possess the attributes of spatiality, non-linearity and randomicity, so we must process much spatial information. Spatial analysis and data management are the advantages of GIS, which can define distribution trend and spatial relations of environmental factors, and show ecological security pattern graphically. Spatial differences of ecological security assessment based on GIS are discussed in this paper, of which the middle and lower reaches of the Liaohe River is taken as a study case. First, to work out pressure-state-response (P-S-R) assessment indicators system, and investigate in person and gather information; second, to digitize the watershed; third, to quantize and calculate by the fuzzy method; last, to construct GIS grid database, and expound spatial differences of ecological security by GIS interpolation and assembly analysis. | Wang Geng 1,2 , Nie Baochi 3, Wang Lin 1 & Wu Wei 1 1. School of Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024, China 2. Urban and Environmental School, Liaoning Normal University, Dalian 116029, China 3. Shenyang Buraue of Water Resources, Shenyang 110013, China. | 2005 | Chinese Journal of Population,Resources and Environment2005,3,4: | 12 |