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Farming and forestry land use changes in china and their driving forces from 1900 to 1980

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science china Earth sciences 2005年第10期 181-191页

作者： GE Quansheng & DAI Junhu institute of geographic {2.s and natural resources research, Chinese Academy of {2.s, beijing 100101, china

A variety of agricultural and forestry land use materials, especially those in the first half of 2.th century, were collected. According to land use change in this period, the whole country is demarcated into seven regions, Northeast china, North china, Northwest and Loess Plateau, Southeast and Coastal Region, Southwest china, Qinghai-Tibetan Plateau, Inner Mongolia and Xinjiang, in proper order by using Cluster Analysis. The farming and forestry land use change in these regions were analyzed. The results show that the total cultivated land areas increased in this period, especially in the 1950s and 1960s the cultivated land area increased more significantly, but differed in different regions, and the most rapid increasing rate was 2.63 percent a year. On the other hand, the forestry land area was increasing in most parts of this period, especially after 1949. But in most regions, the decrease of forestry land area at the end of 1970s is also very obvious. It is regarded that the population increase, food production, natural disasters and some related government policies were among the main driving factors for farming and forestry land use change.

关键词： land use change cultivated land forestry land driving factors 2.th century.

A new DNA algorithm to solve graph coloring problem

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Progress in natural science:Materials International 2007年第6期17卷 733-738页

作者： Jiang Xingpeng1, Li Yin2. Meng Ya3 and Meng Dazhi2.1. National Laboratory of Pattern Recognition,institute of Automation, Chinese Academy of sciences, {2. 100080, china 2. College of Applied sciences, {2. University of Technology, {2. 10002., china 3. School of science, {2. institute of Technology, {2. 100081, china) National Laboratory of Pattern Recognition Institute of Automation Chinese Academy of Sciences Beijing 100080 China College of Applied sciences Beijing University of Technology Beijing 100022 China School of science Beijing Institute of Technology Beijing 100081 China

Using a small quantity of DNA molecules and little experimental time to solve complex problems successfully is a goal of DNA computing. Some NP-hard problems have been solved by DNA computing with lower time complexity than conventional computing. However, this advantage often brings higher space complexity and needs a large number of DNA encoding molecules. One example is graph coloring problem. Current DNA algorithms need exponentially increasing DNA encoding strands with the growing of problem size. Here we propose a new DNA algorithm of graph coloring problem based on the proof of four-color theorem. This algorithm has good properties of needing a relatively small number of operations in polynomial time and needing a small number of DNA encoding molecules (we need only 6R DNA encoding molecules if the number of regions in a graph is R).

关键词： DNA computing NP-hard problem graph coloring problem.

Progress and review of the studies on the end-Triassic mass extinction event

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science china Earth sciences 2005年第12期48卷 2049-2060页

作者： DENG Shenghui1,2. LU Yuanzheng1,2.3 & XU Daoyi4 1. research institute of Petroleum Exploration and Development, {2. 100083, china 2. Key Laboratory of Oil and Gas Reservoir of Petrochina, {2. 100083, china 3. china University of Geosciences, {2. 100083, china 4. institute of Geology, china Earthquake Administration, {2. 10002., china 1. research institute of Petroleum Exploration and Development 100083 Beijing China 2. Key Laboratory of Oil and Gas Reservoir of Petrochina 100083 Beijing China 3. china University of Geosciences 100083 Beijing China 4. institute of Geology China Earthquake Administration 100029 Beijing China

The mass extinction at the end-Triassic is one of the five biggest in the Phanerozoic. However,it is the least well understood among these five events, and only till last decade it became a great academic interesting subject to geologists. The evidences for this event come obviously from bivalves, brachiopods, ammonites, corals, radiolaria, ostracods and foraminifera of marine habitats, and plants and tetrapods of terrestrial realm. By contrast, for some of other groups, such as marine gastropods and marine vertebrates, no mass extinction has been recog-nized yet. The extinction event is strongly marked at specific level but shown a complicated situa-tion at generic and family levels. Dramatic changing of the environment, such as the temperature raise due to the greenhouse effect, the marine anoxic habitats caused by a sudden transgression after the regression at the end of Triassic, has been claimed to be the main cause of the extinction. Many hypotheses have been suggested to demonstrate the mechanisms of the environment changing, among which two popular ones are the bolide impact and volcanic eruption. The Triassic-Jurassic (Tr-J) boundary mass extinction event is still poorly understood because no enough data have been obtained from the Tr-J boundary successional sections of both marine and terrestrial sediments, and most of these studies were regionally restricted. The basic aspects of the event and its associated environmental conditions remain poorly characterized and the causal mechanism or mechanisms are equivocal. Some authors even doubt its occurrence. china has many successionally developed terrestrial and marine Tr-J sections. Detailed studies of these sections may be important and significant for well understanding of the event.

关键词： progress, review, end-Triassic, mass extinction, mechanism, Tr-J boundary.

research progress in the inner surface modification of metal tubes by plasma processing

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Progress in natural science:Materials International 2006年第11期16卷 1119-1126页

作者： ZHANG Guling~ 1,2.**, WU Xingfang~1, GU Weichao~2. CHEN Guangliang~2. FENG Wenran~2. NIU Erwu~2. LI Li~2. L Guohua~2. CHEN Huan~2. FAN Songhua~2. LIU Chizi~2.and YANG Size~2.1. School of Material science and Engineering, University of science and Technology {2., {2. 100083, china 2. {2. National Laboratory for Condensed Matter Physics, institute of Physics, Chinese Academy of sciences, {2. 100080, china) School of Material science and Engineering University of Science and Technology Beijing Beijing 100083 China beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China

The recent progress in inner surface hardening of tubes by plasma processing is summerized. Several techniques of inner surface plasma source ion implantation and deposition are introduced, and their advantages and disadvantages are discussed. The basic principles, technical features and new progress of inner surface plasma source ion implantation methods for metal tubes, which were developed in our laboratory, are described in detail. And perspectives of the future technical development for inner surface ion implantation of tubes are presented.

关键词： PSII metal tubes inner surface surface modification.

Interannual variability of Antarctic Oscillation and its influence on East Asian climate during boreal winter and spring

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science china Earth sciences 2006年第5期49卷 554-560页

作者： FAN Ke1,2.3 & WANG Huijun2.1. Nansen-Zhu International research Center, institute of Atmospheric Physics, Chinese Academy of {2.s, beijing 10002., china 2. Department of Atmospheric {2., Yunnan University, Kunming 650091, china 3. Graduate University of the Chinese Academy of {2.s, beijing 100049, china 1. Nansen-Zhu International research Center Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China 2. Department of Atmospheric science Yunnan University Kunming 650091 China 3. Graduate University of the Chinese Academy of sciences Beijing 100049 China

The interannual variability of Antarctic Oscillation (AAO) and its influence on East Asian climate during both boreal winter and spring are addressed. The results show that the positive AAO anomaly decreases the cold activity over East Asia during both boreal winter and spring. AAO-related barotropic meridional teleconnection from Antarctic to Arctic is found through analysis of mean me- ridional circulations. This meridional teleconnection is remarkable over Eurasia during boreal winter and over the Pacific Ocean during boreal spring. The results also show that zonal mean zonal wind at high latitudes in Southern Hemisphere has well positive correlation with that of Eurasia during boreal winter and has negative correlation with Pacific North American teleconnection (PNA) during boreal spring, which again display the meridional teleconnection. Thus, local meridional teleconnection is a possible linkage for interaction of circulations at mid-high latitudes between both hemispheres.

关键词： Antarctic Oscillation, Eurasian west wind, meridional teleconnection, mean meridional circulation.

research progress of socio-economic water cycle in china

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Journal of geographical sciences 2002年第1期12卷 114-120页

作者： JIA Shao-feng, WANG Guo, ZHANG Shi-feng, YU Gui-rui, WANG Jin-xia, XIA Jun (institute of geographic {2.s and natural resources research, CAS, beijing 100101,china) institute of geographic {2.s and natural resources research CAS 北京 100101

china has made great progress in the study of socio-economic water cycle. She has completed national water resources appraisement and medium to long-term water supply planning. She has been engaging in study on water-deficient regions in North{2. and Northwest{2. for about half a century. For solving water shortage problem in northern{2., she has put forward the famous South-to-North Water Transferring Projects, which has been set as one of the four biggest national projects in the Tenth Five-Year-Plan period although there are still debates. For promoting water use efficiency,{2. has been reforming her water management system, including water right system and water price system. There has already been a case of water right purchase.{2. has also done a lot of research on the interaction between human activity, water and ecosystem. For meeting the need of sustainability and coordinating water resources development and environmental protection, the study of ecological water requirement became very hot in recent years. There are three focuses of socio-economic water cycle study now in{2.: water transfer projects from the south to the north, water resources management and ecological water requirement.

关键词： water cycle socio-economic water cycle sustainable water resources management water security

Antioxidant effects of green tea polyphenols

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Chinese science Bulletin 2003年第4期48卷 315-319页

作者： ZHAO Baolu Laboratory of Visual Information Processing, research Centers of Brain and Cognitive science, {2. of Biophysics, Chinese Academy of sciences, beijing 100101, china Laboratory of Visual Information Processing Research Centers of Brain and Cognitive Science Institute of Biophysics Chinese Academy of Sciences Beijing 100101 China

The unprecedented interest in the antioxidant activity of green tea polyphenols (GTP) is due to the appar-ent health benefits of tea drinking and the experimental re-sults with the polyphenols. The results suggest that the gal-loylated catechins show stronger antioxidant effect than that of nongalloylated catechins and the double bond in C ring also plays an important role in this effect. There are synergic effects between different catechins and the antioxidant effect of (+)-epimers is stronger than that of (-)-epimers. The active site to scavenge free radicals mainly locates in p-hydroxyl of phenol in gallic acid and hydroxyl of phenol in the pyrane also shows activity. The large p bond in chromane and benzene ring of catechin is the structure base for their anti-oxidant effects. The prevent effect of GTP against diseases and their redox regulation in cell signal pathway are very important to be studied in the future.

关键词：绿茶茶多酚天然抗氧化剂抗氧化作用生物类黄酮自由基抗衰老

Photogeneration of the free radicals and singlet oxygen by chrysophanol from rheum

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science china Chemistry 2004年第5期47卷 381-387页

作者： RAO Jing1,2. XIE Jie1, ZHAO Jingquan1 & ZHU Teng2.1. Key Laboratory of Photochemistry, Center for Molecular science, institute of Chemistry, The Chinese Academy of sciences, beijing 100080, china 2. University of science and Technology beijing, beijing 10083, china 1. Key Laboratory of Photochemistry Center for Molecular Science Institute of Chemistry The Chinese Academy of Sciences 100080 Beijing China 2. University of science and Technology beijing 10083 Beijing China

In the current work, chryosphanol (MHAQ) was isolated and purified from rheum, and the photosensitization activities were studied. In nitrogen-saturated DMSO solution, irradia- tion of chryosphanol (MHAQ) with visible light (>430 nm) produced the semiquinone radical anions (MHAQ??), which was intensified significantly by an electron donor NADH, suggesting electron transfer between the excited and ground state photosensitizer molecules. In an air-saturated DMSO solution, superoxide radical anions (O2.), trapped by DMPO, were detected. ?? It was proved that O2.was not originated from the singlet oxygen (1O2. but dependent on DMPO, ?? chrysophanol, oxygen and the irradiation time. The singlet oxygen and OH could also be pro- ? duced by the photosensitization of the photosensitizer. These suggest that chrysophanol pos- sesses the photosensitization activity via Type I mechanism and Type II mechanism. To evaluate the photosensitization activities of MHAQ, emodin and mixed anthraquinone derivatives ex- tracted from rheum, the relative productivities of O2.were estimated to be 1.8, 1.1 and 1.0 re- ?? spectively and the quantum yields for singlet oxygen to be 0.36, 0.53 and 0.14 respectively. Therefore, these low-cost pigments may be potentially used as phototherapeutic medicine for some kind of vascular diseases or photo-activated pesticides.

关键词： chrysophanol, ESR, semiquinone radical anions, superoxide radical anions, hydroxyl radical, singlet oxygen.

中国科学院生态系统网络观测与模拟重点实验室CERN综合研究中心研究成果与发展

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自然资源学报 2010年第9期25卷 1458-1467页

作者： Synthesis research Center of Chinese Ecosystem research Network,CAS({2. of geographic sciences and natural resources research,CAS,beijing 100101,china) 中国科学院地理科学与资源研究所北京100101

介绍了中国生态系统研究网络(CERN)综合研究中心成立以来的发展历程和主要研究成果,以及未来研究方向及预期发展。取得的代表性研究成果主要有:CERN动态监测数据与生态系统空间信息数据管理和共享系统的开发、陆地生态系统碳和水热通量... 详细信息

介绍了中国生态系统研究网络(CERN)综合研究中心成立以来的发展历程和主要研究成果,以及未来研究方向及预期发展。取得的代表性研究成果主要有:CERN动态监测数据与生态系统空间信息数据管理和共享系统的开发、陆地生态系统碳和水热通量观测研究、陆地生态系统碳储量的时空格局特征研究、陆地生态系统多尺度模拟综合集成研究和青藏高原生态系统格局与全球变化相互作用关系研究等。未来的研究方向主要集中在陆地生态系统碳氮水循环及其耦合,区域碳汇功能动态,生态敏感区、脆弱区和过渡区对全球气候变化的响应与适应,生态监测、模拟与生态信息应用以及全球气候变化主要因子对生态系统关键过程的影响。未来除了履行CERN综合研究中心的基本职能外,争取在以上研究方向取得有国际影响的开拓性研究成果。

关键词： CERN 综合研究中心研究成果陆地生态系统