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    题名 作者 年代 出处 被引量
1Highly Pathogenic H5N1 Influenza Virus Infection in Migratory Birds显示文摘Jinhua Liu et al.College of Veterinary Medicine, China Agricultural University, Beijing 100094, China. 2005中国实验动物学报2005,13,S1:114
2Reconstruction of precipitation variation from tree rings in recent 1000 years in Delingha, Qinghai显示文摘Using seven well-replicated Qilian juniper (Sabina przewalskii Kom.) ring-width chronologies developed at Zongwulong and Shalike Mts. in the northeastern part of the Qaidam Basin annual precipitation from previous July to current June in the recent 1000 years was re- constructed for Delingha. The reconstruction can capture 63.1% of precipitation variance and the equation was stable over time. For the reconstructed precipitation, wet periods occurred in AD1520—1633 and 1933—2001, whereas dry intervals in 1429—1519 and 1634—1741. In ad- dition, the magnitude in precipitation variation was lower before 1430 with about 15 mm, but it increased to 30 mm during the period of 1430 to 1850. After 1850, the precipitation variance de- creased again. In contrast to the increase in temperature, a decrease in annual precipitation was evident since the 1990s. The agreement in low-frequency variation between the reconstruction and the glacier accumulation and particulate content in Dunde ice cores during the recent several hundred years suggested that the precipitation reconstructed in this study was rather reliable, and represented a regional signal. This 1000-year reconstruction could benefit our understanding of climatic variation in decadal to century-scale in this region, and provide basic data to climate models and to prediction of future climate in the 21st century.SHAO Xuemei1, HUANG Lei1, LIU Hongbin2, LIANG Eryuan1, FANG Xiuqi3 & WANG Lili1 1. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China 2. National Climate Center, Beijing 100081, China 3. Beijing Normal University, Beijing 100875, China 2005Science China Earth Sciences2005,48,7:113
3On adjacent-vertex-distinguishing total coloring of graphs显示文摘In this paper, we present a new concept of the adjacent-vertex-distinguishing total coloring of graphs (briefly, AVDTC of graphs) and, meanwhile, have obtained the adjacent-vertex-distinguishing total chromatic number of some graphs such as cycle, complete graph, complete bipartite graph, fan, wheel and tree.ZHANG Zhongfu, CHEN Xiang’en, LI Jingwen, YAO Bing, LU Xinzhong & WANG Jianfang College of Mathematics and Information Science, Northwest Normal University, Lanzhou 730070, China Department of Computer, Lanzhou Normal College, Lanzhou 730070, China Institute of Applied Mathematics, Lanzhou Jiaotong University, Lanzhou 730070, China College of Information and Electrical Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China Institute of Applied Mathematics, Chinese Academy of Sciences, Beijing 100080, China 2005Science China Mathematics2005,48,3:173
4Design of a new dynamical core for global atmospheric models based on some efficient numerical methods显示文摘A careful study on the integral properties of the primitive hydrostatic balance equations for baroclinic atmosphere is carried out, and a new scheme todesign the global adiabatic model of atmospheric dynamics ispresented. This scheme includes a method of weighted equal-areamesh and a fully discrete finite difference method with quadraticand linear conservations for solving the primitive equationsystem. Using this scheme, we established a new dynamical corewith adjustable high resolution acceptable to the availablecomputer capability, which can be very stable without anyfiltering and smoothing. Especially, some important integralproperties are kept unchanged, such as the anti-symmetries of thehorizontal advection operators and the vertical convectionoperator, the mass conservation, the effective energy conservationunder the standard stratification approximation, and so on. Somenumerical tests on the new dynamical core, respectively regardingits global conservations and its integrated performances inclimatic modeling, incorporated with the physical packagesfrom the Community Atmospheric Model Version 2 (CAM2) of NationalCenter for Atmospheric Research (NCAR), are included.WANG Bin, WAN Hui, Jl Zhongzhen, ZHANG Xin, YU Rucong, YU Yongqiang & LIU HongtaoState Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China Department of Computational Mathematics, Academy of Mathematics and System Sciences, Peking University, Beijing 100871, China 2004Science China Mathematics2004,47,z1:92
5Hepatocellular Carcinoma-Cause,Treatment and Metastasis显示文摘In the recent decades, the incidence of hepatocellular carcinoma (HCC) has been found to be increasing in males in some countries. In China, HCC ranked second of cancer mortality since 1990s. Hepatitis B and C viruses (HBV and HCV) and dietary aflatoxin intake remain the major causative factors of HCC. Surgery plays a major role in the treatment of HCC, particularly for small HCC. Downstaging unresectable huge HCC to smaller HCC and followed by resection will probably be a new approach for further study. Liver transplantation is indicated for small HCC, however, some issues remain to be solved.Different modes of 'regional cancer therapy for HCC' have been tried. Systemic chemotherapy has been disappointing in the past but the future can be promising.Biotherapy, such as cytokines, differentiation inducers,anti-angiogenic agents, gene therapy and tumor vaccine will probably play a role, particularly in the prevention of tumor recurrence. HCC invasiveness is currently the major target of study. Tremendous works have been done at the molecular level, which will provide clues for biomarker of HCC progressionas well as targets for intervention.Zhao-You Tang Liver Cancer Institute & Zhongshan Hospital of Fudan University Professor of Surgery Chairman.Liver Cancer Institute of Fudan University(previous Liver Cancer Institute of Shanghai Medical University)136 Yixueyuan Road,Zhongshan Hospital,Shanghai 200032,China. 2001World Journal of Gastroenterology2001,7,4:213
6Establishment of cell clones with different metastatic potential from the metastatic hepatocellular carcinoma cell line MHCC97显示文摘ALM To establish clone cells with different metastatic potential for the study of metastasis-related mechanisms. METHODS Cloning procedure was performed on parental hepatocellular carcinoma (HCC) cell line MHCC97. andbiological characteristics of the target clones selected by in vivo screening were studied.``RESULTS Two clones with high MHCC97-H and IowMHCC9--L1 metastatic potential were isolated from theparent cell line. Compared with MHCC97-L. MHCC97-H hadsmaller cell size average cell diameter 43 um vs 50 μmand faster in vitro and in vivo growth rate tumor celldoubling time was 34.2 h vs 60.0 h. The main ranges ofchromosomes were 5.5 58 in MHCC97-H and 57 62 inMHCC97-L. Boyden chamber in vitro invasion assay demonstrated that the number of penetrating cells through the artificial basement membrane was 137.5 - 11 .0) cellsfield for MHC_C99--H vs 17.7 - 6.3) field for MHCC97-L.The proportions of cells in GO Gl phase. S phase, and G_ M phase for MHCC97-H MHCC97-L were 0.56 6.65.0.28 0.25 and 0.l6 0.10, respectively, as measured by flow cytometry. The serum AFP levels in nude mice 5 wk after orthotopic implantation of tumor tissue were ( 24666 μg. L for MHCC97-H and (91- 66) μg' L 1 for MHCC97L. The pulmonary metastatic rate was 100% (10-10) vs40% 4- 10).``CONCLUSION Two clones of the same genetic background but with different biological behaviors were established, which could be valuable models for investigation on HCC metastasis.Yan Li Zhao-You Tang Sheng-Long Ye Yin-Kun Liu Jie Chen Qiong Xue Jun Chen Dong-Mei Gao Wei-Hua Bao Liver Cancer Institute and Zhongshan Hospital of Fudan University (Former Liver Cancer Institute of Shanghai Medical University),Shanghai 200032,China 2001World Journal of Gastroenterology2001,7,5:111
7Quantitative analysis of vascular endothelial growth factor, microvascular density and their clinicopathologic features in human hepatocellular carcinoma显示文摘BACKGROUND: Angiogenesis is known to be essential to the survival, growth, invasion, and metastasis of tumor cells. Vascular endothelial growth factor (VEGF) are an important angiogenic factor regulating tumor angiogenesis, but its significance and tumor pathologic features are un- clear in hepatocellular carcinoma (HCC). In the present study, we analyzed expression of tissue VEGF, alteration of microvascular density (MVD) in microvessel angiogenesis, development and metastasis of HCC, and level of serum VEGF in differential diagnosis of benign and malignant liv- er diseases. METHODS: Tumor specimens were prospectively collected from HCC patients undergoing resection. Total RNAs were extracted and the expression levels were detected from different parts of HCC tissues. The cellular distributions of VEGF and MVD of liver tumors and their paracancerous and distal cancerous tissues were investigated by streptavi- din peroxidase (S-P) immunohistochemistry, respectively. The VEGF levels of circulating blood and hepatoma tissues were measured by enzyme-linked immunosorbent assay. RESULTS: The incidence of VEGF expression was 63.9% in HCCs (23/36 cases), 78.3% in non-encapsulated HCCs (18/23), and 90.9% in HCCs with extrahepatic metastasis (10/11), respectively. The VEGF expression was tightly correlated with MVD (P <0.01). The MVD in HCC with metastasis, low differentiation or non-encapsulation was significantly higher than that in HCC with intact capsule, high differentiation, or no metastasis. No significant diffe- rence was found between VEGF, MVD, tumor size, and hepatitis virus infection. The level of total RNA in HCC tis- sues was significantly lower but the VEGF level significantly higher than those in paracancerous or distal cancerous ones (P<0.01). The abnormal expression levels of VEGF in sera of HCC patients were directly correlated with the me- tastasis and recurrence of tumors. CONCLUSION: The high expression of VEGF and abnor- mality of tissue MVD are useful predictors for vascular inva- sion and metastasis of liver tumors.Deng-Fu Yao, Xin-Hua Wu, Yong Zhu, Gong-Sheng Shi, Zhi-Zhen Dong, Deng-Bing Yao, Wei Wu, Li-Wei Qiu and Xian-Yong Meng Nantong, China Research Center of Clinical Molecular Biology , Department of Pathology and Department of Gastroenterology , Affiliated Hos- pital of Nantong University Department of Diagnostics , and Institute of Neurosciences , Nantong University Nantong 226001, China 2005Hepatobiliary & Pancreatic Diseases International2005,4,2:81
8Homotopic mapping solving method for gain fluency of a laser pulse amplifier显示文摘The model for gain fluency of a laser pulse amplifier is studied. Using the homotopic mapping method, firstly, the system of the original model is packed up standardization; secondly, introducing a homotopic mapping, taking the property of the mapping, inducing a contrived parameter, the solving of a nonlinear problem translates into the solving of a linear problem. Then the approximate expressions of the solution for the corresponding model are obtained. And the precision for the approximate solution is compared. It illuminates that the obtained approximate solution using the homotopic mapping method possesses higher approximate degree. At one time, the expansion of solution through the homotopic mapping method can be kept in the analytic operation. Thus it also enables us through differential and integral operations to obtain other physics behavior for the gain fluency of laser pulse amplifier.MO JiaQi1,2 1 Anhui Normal University, Wuhu 241000, China 2 Division of Computational Science, E-Institutes of Shanghai Universities, at SJTU, Shanghai 200240, China 2009Science China(Physics,Mechanics & Astronomy)2009,52,7:124
9Source mechanism of strong aftershocks (M_s≥5.6) of the 2008/05/12 Wenchuan earthquake and the implication for seismotectonics显示文摘Dozens of >M5, hundreds of >M4, and much more >M3 aftershocks occurred after the 2008/05/12 Wenchuan earthquake, which were well recorded by permanent and portable seismic stations. After relocated with P arrival, the >M3 aftershocks show two trends of distribution, with most of the aftershocks located along the north-east strike consistent with Longmenshan fault system, yet there is a north-west trend around the epicenter. It seems that substantially more aftershocks occur in regions with crystalline bedrocks. Then we collected waveform data from National Digital Seismograph Network and regional seismograph network of China, and employed 'Cut and Paste' method to obtain focal mechanisms and depths of the big aftershocks (M≥5.6). While most of those aftershocks show thrust mechanism, there are some strike slip earthquakes in the northern-most end of the rupture. Focal mechanisms show that the events located on the southern part of central Beichuan-Yingxiu Fault (BY) are mainly thrust earthquakes, which is consistent with initial mechanism of the main shock rupture. In the north part the aftershocks along the BY are also dominated by thrust slip, which is quite different from the right slip rupture of the main shock. Around Qingchuan-Pingwu Fault, the focal mechanisms are dominated by right-slip rupture with large depths (~18 km). So we suspected that in the north part the main shock might rupture on two faults: Beichuan Fault and Qingchuan-Pingwu Fault. The complex pattern of aftershock mechanisms argues for presence of a complicated fault system in the Longmenshan area.ZHENG Yong1,2,MA HongSheng3,Lü Jian4,NI SiDao5,LI YingChun6 & WEI ShengJi2 1 Institute of Geodesy and Geophysics,Chinese Academy of Sciences,Wuhan 430077,China 2 Institute of Geophysics,Chinese Earthquake Administration,Beijing 100086,China 3 Institute of Earthquake Science,Chinese Earthquake Administration,Beijing 100086,China 4 Earthquake Administration of Jiangxi Province,Nanchang 330039,China 5 School of Earth and Space Science,University of Science and Technology of China,Hefei 230026,China 6 Earthquake Administration of Jiangsu Province,Nanjing 210014,China 2009Science China Earth Sciences2009,52,6:100
10Increasing the frequency of CIK cells adoptive immunotherapy may decrease risk of death in gastric cancer patients显示文摘AIM: To analyze the correlation between cytokineinduced killer (CIK) cells adoptive immunotherapy and cancer-related death in gastric cancer patients. METHODS: One hundred and fifty-six gastric cancer patients after operation at the Third Affiliated Hospital of Soochow University were enrolled in this study. Their clinical data including demographic characteristics, operation time, tumor size, pathological type and staging, tumor metastasis, outcome of chemotherapy or CIK cells adoptive immunotherapy, survival time or time of death were collected with a standard structured questionnaire. Kaplan-Meier method was used to estimate the median survival time, and the 2- and 5- year survival rates. Hazard risk (HR) and 95% confidence interval (95% CI) of CIK cells adoptive immunotherapy for gastric cancer were calculated using the two-stage time-dependent covariates Cox model. RESULTS: The survival time of gastric cancer patients was longer after CIK cells adoptive immunotherapy than after chemotherapy (χ 2 = 10.907, P = 0.001). The median survival time of gastric cancer patients was also longer after CIK cells adoptive immunotherapy than after chemotherapy (49 mo vs 27 mo, P < 0.05). The 2- and 5-year survival rates of gastric cancer patients were significantly higher after CIK cells adoptive immunotherapy than after chemotherapy (73.5% vs 52.6%, 40.4% vs 23.9%, P < 0.05). A significant difference was observed in the survival curve for patients who received CIK cells adoptive immunotherapy (0, 1-10, 11-25, and over 25 frequencies) (χ 2 = 14.534, P = 0.002). The frequencies of CIK cells adoptive immunotherapy were significantly related with the decreasing risk of death in gastric cancer patients after adjustment for sex and age of the patients, tumor stage and relapse (HR = 0.54, 95% CI: 0.36-0.80) when the first stage Cox model was used to define the subjects who remained alive beyond 36 mo as survivors. However, no correlation was observed between the frequencies of death in CIK cells adoptive immunotherapy and the risk of gastric cancer patients (HR = 1.09, 95% CI: 0.63-0.89) when the second stage Cox model was used to define the subjects who survived for more than 36 mo as survivors. CONCLUSION: The survival time of the gastric cancer patients treated with chemotherapy combined with CIK cells adoptive immunotherapy is significantly longer than that of the patients treated with chemotherapy alone and increasing the frequency of CIK cells adoptive immunotherapy seems to benefit patients more.Jing-Ting Jiang, Chang-Ping Wu, Lu-Jun Chen, Xiao Zheng, Department of Tumor Biological Treatment, Third Affiliated Hospital of Soochow University, Changzhou 213003, Jiangsu Province, China Yi-Bei Zhu, Jing Sun, Xue-Guang Zhang, Key Laboratory of Stem Cell of Jiangsu Province, Institute of Biotechnology, Key Laboratory of Clinical Immunology of Jiangsu Province, Soochow University, Suzhou 215123, Jiangsu Province, China Yue-Ping Shen, Wen-Xiang Wei, Department of Medicine, Soochow University, Suzhou 215123, Jiangsu Province, China Bin-Feng Lu, Department of Immunology, University of Pitts- burgh School of Medicine, Pittsburgh, PA 15261, United States 2010World Journal of Gastroenterology2010,16,48:82
11Further support for a Cretaceous age for the feathered-dinosaur beds of Liaoning,China:New ^(40)Ar/^(39)Ar dating of the Yixian and Tuchengzi Formations显示文摘We report new 40Ar/39Ar dating results ob-tained from total fusion and incremental-heating analyses of sanidine and biotite from three tuffs found interbedded within the fossil-bearing deposits of Liaoning, northeast China. The first is a new sample of the Bed 6 Sihetun tuff from the Yixian Formation, previously dated by our team as middle Early Cretaceous, and recently considered by Lo et al., partially reset due to metamorphism from a nearby ba-saltic sill. The second is the Yixian Bed 9 tuff from Heng-daozi considered by Lo et al. to be unaffected by metamor-phism and whose age, based on total fusion 40Ar/39Ar dating of biotite, argues for a Jurassic age for the Yixian Formation. The third tuff is a previously undated tuff from the upper part of the underlying Tuchengzi Formation. Single crystal total fusion 40Ar/39Ar analyses of the Sihetun sanidine showed homogeneous radiogenic Ar, Ca/K ratios, excellent reproducibility and gave a mean age of 125.0 ± 0.18 (1SD) ± 0.04 (SE) Ma. Single sanidineC. C. Swisher III, WANG Xiaolin, ZHOU Zhonghe, WANG Yuanqing, JIN Fan, ZHANG Jiangyong , XU Xing, ZHANG Fucheng & WANG YuanDepartment of Geological Sciences, Wright Labs, Rutgers University, Piscataway, New Jersey 08854, USA (e-mail: cswish@rutgers. rci.e 2002Chinese Science Bulletin2002,47,2:83
12SHEsis,a powerful software platform for analyses of linkage disequilibrium,haplotype construction,and genetic association at polymorphism loci显示文摘In multiloci-based genetic association studies of complex diseases, a powerful and high efficient tool for analyses oflinkage disequilibrium (LD) between markers, haplotype distributions and many chi-square/p values with a large numberof samples has been sought for long. In order to achieve the goal of obtaining meaningful results directly from raw data,we developed a robust and user-friendly software platform with a series of tools for analysis in association study withhigh efficiency. The platform has been well evaluated by several sets of real data.Yong Yong SHI1,2, Lin HE2,3,*1Bio-X Life Science Research Center, Shanghai Jiao Tong University, Shanghai, China 2Institute for Nutritional Sciences, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Shanghai,China 3NHGG, Bio-X Center, Shanghai Jiao Tong University, Shanghai, China 2005Cell Research2005,15,2:375
13S-rough sets and knowledge separation显示文摘The conceptions of the knowledge screen generated by S-rough sets are given: f- screen and - screen , and then puts forward - filter theorem, - filter theorem of knowledge. At last, the applications of knowledge separation are given according to - screen and - screen.Shi Kaiquan 1,21. School of Mathematics and System Sciences, Liaocheng University, Liaocheng 252059, P. R. China 2. School of Mathematics and System Sciences, Shandong University, Jinan 250100, P. R. China 2005Journal of Systems Engineering and Electronics2005,16,2:104
14全国公示语翻译现状的调查与分析显示文摘本研究通过对全国公示语翻译与使用现状进行调查,了解外籍人士对公示语翻译与使用的满意度和需求,比较中外在公示语的翻译与使用方面的异同,探讨公示语的翻译与使用的功能性和语用性问题及解决对策,确认公示语翻译与使用的发展趋势、重点和难点;为翻译、教学研究机构提供公示语翻译与使用方面的建议,促进公示语的引进、翻译与使用,并为制定国家公示语翻译标准提供参考依据。研究者提出翻译者要更关注信息接受者的感受;翻译实践要更贴近现实,理论研究要更创新求真;并提出由中外专家结合进行研究是满足外籍人员公示语信息需求的最佳翻译工作组合模式。报告建议由中国翻译协会等机构形成强势组合,加快公示语翻译和国际化都市、旅游目的地信息服务体系建设。C-E Signs Research Center ( Beijing International Studies University) 2007中国翻译2007,28,5:99
15Boundary-processing-technique in EMD method and Hilbert transform显示文摘By virtue of neural network, a series of signals is extended forward and backward, as a result, two additional maxima and two additional minima are obtained at both ends of the original data set, with which the EMD decomposition can be exactly achieved with cubic spline interpolation. Meanwhile, by using of neural network every IMF component can also be extended forward and backward, which effectively restrains the end effect, thus the veracious Hilbert spectra are achieved. Verifications of the sample signals and the actual surface elevation of sea waves show that the present extension method is relatively accurate.DENG Yongjun, WANG Wei, QIAN Chengchun, WANG Zhong & DAI DejunNetwork Center, Ocean University of Qingdao. Qingdao 266003, China Physical Oceanography Laboratory, Ocean Universily of Qingdao, Qingdao 266003, China 2001Chinese Science Bulletin2001,46,11:91
16Extension theory and its application显示文摘The article Extension Set and Non-compatible Problems was published in 1983. It proclaimed the birth of extension theory. Its objects of study are contradictory problems in the realistic world; its theoretical pillars are matter element theory and extension set theory. Its basic methods are extension methods. Its practical methods are extension engineering methods,CAI WenResearch Institute of Matter-Element Analysis , Guangdong University of Technology , Guangzhou 510090, China 1999Chinese Science Bulletin1999,44,17:130
17我国面临快速增长的终末期肾病治疗负担显示文摘目的报告2008年我国终末期肾脏病维持性透析患病率和发病率,并估计未来维持性透析的趋势。方法中国医院协会血液净化中心管理分会制定调查表,以透析登记软件及纸质版形式下发至各省、自治区和直辖市的血液净化中心管理分会/血液净化质量控制中心,收集各透析室的数据,包括2007年底和2008年底患者数量,以及2008年新进入透析的患者数量;患者的性别和年龄构成;导致终末期肾脏病(ESRD)的原因以及所有死亡患者的原因。分析2007和2008年底ESRD的点患病率、2008年ESRD发病率、ESRD病因以及死亡原因构成。结果全国31个省、自治区和直辖市中,27个应答。2007年底,共报告65074例ESRD患者,点患病率为每百万人口51.7;2008年底患者数增至102863例,点患病率为每百万人口79.1,患病率增长52.9%。2008年ESRD新患者数为45423例,发病率每百万人口36.1。ESRD的病因依次为肾小球肾炎(45%)、糖尿病(19%)、高血压(13%)、多囊肾病(2%)和其他或未知(20%)。ESRD主要死亡原因是心血管疾病(31%)、中风(20.3%)、感染(19.9%)和其他(28.8%)。结论虽然我国ESRD的患病率显著低于其他亚洲国家和地区,但发病率极高,未来几年患病率也将快速增加,从而增加我国ESRD的治疗负担。Li Zuo M.D.1 and Mei Wang M.D.2 for Chinese Society of Blood Purification Institute of Nephrology,Peking University First 1 Hospital Institute of Nephrology,Peking University People’s Hospital 2 2010中国血液净化2010,,1:145
18急性病毒性心肌炎的药物治疗观察显示文摘目的 全国十二家大型医院协作观察中西医结合治疗急性病毒性心肌炎疗效。方法 对 10 2 8例临床诊断为急性病毒性心肌炎患者随机各分两组 ,治疗组 60 2例 ,用中西医结合 (黄芪、牛磺酸、泛葵利酮、抗心律失常药等)治疗 ;对照组 4 2 6例 ,用常规 (极化液、抗心律失常药等 )治疗。结果 中西医结合治疗组临床症状改善、外周血肠道病毒阴转、心电图ST T改变及房室传导阻滞、阵发性心房颤动、窦房传导阻滞等恢复均优于对照组(P <0 .0 1、0 .0 5 ) ;对早搏及心功能改善两组间无统计学差异(P <0 .0 5 )。结论 在目前对急性病毒性心肌炎无特效药物治疗的情况下 ,采用中西医结合治疗可作为一种治疗手段。Collaborative Group of “Key National Medical Projects for the Ninth Five Year Plan Research” (Correspondence: YANG Yingzhen, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital,Shanghai Medical University,Shanghai 200032) 1999中华心血管病杂志1999,27,6:94
19Spatiotemporal variations of vegetation cover on the Chinese Loess Plateau(1981―2006):Impacts of climate changes and human activities显示文摘Spatiotemporal variations of Chinese Loess Plateau vegetation cover during 1981-2006 have been investigated using GIMMS and SPOT VGT NDVI data and the cause of vegetation cover changes has been analyzed, considering the climate changes and human activities. Vegetation cover changes on the Loess Plateau have experienced four stages as follows: (1) vegetation cover showed a continued increasing phase during 1981―1989; (2) vegetation cover changes came into a relative steady phase with small fluctuations during 1990―1998; (3) vegetation cover declined rapidly during 1999―2001; and (4) vegetation cover increased rapidly during 2002―2006. The vegetation cover changes of the Loess Plateau show a notable spatial difference. The vegetation cover has obviously increased in the Inner Mongolia and Ningxia plain along the Yellow River and the ecological rehabilitated region of Ordos Plateau, however the vegetation cover evidently decreased in the hilly and gully areas of Loess Plateau, Liupan Mountains region and the northern hillside of Qinling Mountains. The response of NDVI to climate changes varied with different vegetation types. NDVI of sandy land vegetation, grassland and cultivated land show a significant increasing trend, but forest shows a decreasing trend. The results obtained in this study show that the spatiotemporal variations of vegetation cover are the outcome of climate changes and human activities. Temperature is a control factor of the seasonal change of vegetation growth. The increased temperature makes soil drier and unfavors vegetation growth in summer, but it favors vegetation growth in spring and autumn because of a longer growing period. There is a significant correlation between vegetation cover and precipitation and thus, the change in precipitation is an important factor for vegetation variation. The improved agricultural production has resulted in an increase of NDVI in the farmland, and the implementation of large-scale vegetation construction has led to some beneficial effect in ecology.XIN ZhongBao1,2, XU JiongXin1 & ZHENG Wei1, 2 1 Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China 2 Graduate University of the Chinese Academy of Sciences, Beijing 100049, China 2008Science China Earth Sciences2008,51,1:112
20Study on the prevalence of benlgn prostatic hyperplasia and prostatic cancer in China显示文摘StudyontheprevalenceofbenlgnprostatichyperplasiaandprostaticcancerinChinaGuFang-liu(顾方六)InstituteofUrology,BeijingMedicalUniv...$$$$ Gu Fang-liu(顾方六)Institute of Urology,Beijing Medical University,Beijing 100083,China 1994生殖医学杂志1994,3,S1:116
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