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Origin of the Red Earth sequence on the northeastern Tibetan Plateau and its implications for regional aridity since the middle Miocene

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Science china Earth {1. 2006年第5期49卷 505-517页

作者： wang Xianyan1,7, LU Huayu1,2, JI Junfeg3, wang Xiaoyong1,7, ZHAO Jingbo4, HUANG Baochun5 & li Zhen6 1. SKLLQG, institute of Earth Environment, chinese academy of sciences, Xi’an 710075, china 2. Department of Urban and Resources sciences, Nanjing University, Nanjing 210093, china 3. Department of Earth sciences, Nanjing University, Nanjing 210093, china 4. Department of Geography, Shaanxi Normal University, Xi’an 710062, china 5. institute of Geology and Geophysics, chinese academy of sciences, beijing 100029, china 6 Department of Geography, Qinghai Normal University, Xining 810008, china 7. Graduate School of the chinese academy of sciences, beijing 100039, china SKLLQG Institute of Earth Environment Chinese Academy of Sciences Xi’an China Graduate School of the chinese academy of sciences Beijing China Department of Urban and Resources sciences Nanjing University Nanjing China Department of Earth sciences Nanjing University Nanjing China Department of Geography Shaanxi Normal University Xi’an China institute of Geology and Geophysics Chinese Academy of Sciences Beijing China Department of Geography Qinghai Normal University Xining China

The Red Earth deposit around Xining, northeastern Tibetan Plateau, has beenstudied in terms of soil micro-structure, grain-size distribution, major- and trace-elementchemistry and magne-tostratigraphy. Field investigations indicate that the Red Earth sequenceconsists of 25 visually definable yellow-brown and weakly-developed soils interbedded with reddishstrongly-developed soils, and has a similar structure to the aeolian Red Clay deposit on the {1.Loess Plateau. Grain-size analysis shows that the Red Earth deposit is very fine-grained with anegligible sand fraction ( > 63 μm). Thin-section observations under light microscopy show that thedeposit has a clayey texture and the coarse fraction ( > 1. μm) mainly consists of quartz,feldspar and micas. Pyroxene and hornblende were also observed. This mineralogical composition ofthe coarse fraction is similar to that of the Quaternary loess. In addition, all of the mineralgrains are semi angular semi-angular and are generally finer than 63 μm. There is a good agreementbetween the major and minor trace element chemistry of loess-soil units and the Red Earth *** REE distributions of the loess-soil and the Red Earth deposit are similar in shape, withenriched LREE and fairly flat HREE profiles and a clear negative Eu anomaly. The geochemicalcharacteristics of the Red Earth deposit are also identical to those of upper continental crust,thus indicating a wind-blown origin. Magnetostratigraphic investigation shows that onset of the RedEarth deposition predates 1..4 Ma BP (1..6 Ma at a nearby site). The distribution of the reportedMiocene aeolian loess at Qin''an of the Loess Plateau is still unknown. Our results indicate thatthis aeolian deposit had extended to the northeastern Tibetan Plateau by at least the middleMiocene. The similarity of the element geochemistry between the Red Earth deposit and the overlyingloess shows that they may have similar sources and dynamic transport system, and may indicate thatthe

关键词： Red Earth deposit, Northeastern Tibetan Plateau, aeolian deposit, aridity of Asia, the middle Miocene.

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Two-Dimensional Graphs Moving by Mean Curvature Flow

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Acta Mathematica Sinica,English Series 2002年第2期18卷 209-224页

作者： CHEN Jing Yi Department of mathematics.The University of British Columbia.Vancouver.B.C..Canada V6T 1Z2 E-mail:jychen@math.ubc.cali Jia Yu institute of mathematics.academy of mathematics and system sciences.chinese academy of sciences.beijing 100080.P.R.china Department of mathematics.Fudan University.Shanghai 200433.P.R.china E-mail:lijia@math03.math.ac.cnTIAN Gang Department of mathematics,MIT.Cambridge.MA 02139.U.S.A.E-mail:tian@math,mit.edu Department of mathematics The University of British Columbia Vancouver B. C. Canada V6T 1Z2 institute of {1. Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing P. R. China Department of mathematics Fudan University Shanghai P. R. China Department of mathematics MIT Cambridge U.S.A.

A surface E is a graph in R^4 if there is a unit constant 2-form ω on R^4 such that ≥v_0>0 where{e_1.e_2}is an orthonormal frame on Σ.We prove *** v_0≥on the initial snrface,then the mean curvature flow has a glob... 详细信息

A surface E is a graph in R^4 if there is a unit constant 2-form ω on R^4 such that 1.e_2.ω>≥v_0>0 where{e_1.e_2}is an orthonormal frame on Σ.We prove *** v_0≥on the initial snrface,then the mean curvature flow has a global solution and the scaled surfaces converge to a self-similar solution.A surface Σ is a graph in M_1.M_2 where M_1.and M_2 are Riemann surfaces. if1.e_2.ω>≥v_0>0 where w_1.is a Khler form on M_*** prove *** M is a Khler-Einstein surface with scalar curvature R.v_0≥ on the initial surface,then the mean curvature flow has a global solution and it sub-converges to a minimal surface,*** addition.R≥0 it converges to a totally geodesic surface which is holomorphic.

关键词： Mean curvature flow 2-dimensional graphs in R^4,Self-similar solution

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Simulation of freezing and melting of soil on the northeast Tibetan Plateau

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chinese Science Bulletin 2011年第20期56卷 2145-2155页

作者： XIA Kun 1,2,3,LUO Yong 2,4,5 & li WeiPing 2 1 institute of Atmospheric Physics,chinese academy of sciences,beijing 100029,china 2National Climate Center,china Meteorological Administration,beijing 100081,china 3Graduate University of chinese academy of sciences,beijing 100049,china 4 Center for Earth system Science,Tsinghua University,beijing 100084,china 5Key Laboratory of Earth system Numerical Simulation,Ministry of Education,beijing 100084,china institute of Atmospheric Physics Chinese Academy of Sciences Beijing China National Climate Center China Meteorological Administration Beijing China Graduate University of chinese academy of sciences Beijing China Center for Earth system Science Tsinghua University Beijing China Key Laboratory of Earth system Numerical Simulation Ministry of Education Beijing China

Using observational data spanning the period from February to December 2009 and recorded at the Suli station in Qinghai Province,the land-surface model CLM3.0 was employed to simulate the freezing and melting of *** results indicate that the simulated soil temperature is higher than the observed soil temperature and the ultimate thawing date is earlier than the observed date during the melting *** the freezing period,the simulated soil temperature is lower than the observed soil temperature and the ultimate freezing of the deep soil is earlier than that ***,the simulation of freezing is better than that of melting,and the simulation of a shallow layer is better than that of a deeper *** the original CLM3.0,it is assumed that frozen soil begins to melt when the soil temperature exceeds 0C,which is inconsistent with *** critical freeze-thaw temperature was calculated according to thermodynamics equations and the freeze-thaw condition was *** this work,the melting rate for frozen soil was reduced using the modified scheme,and the simulated soil temperature was lowered. Meanwhile,the refreezing of soil during the melting season was well simulated and more closely matched ***,it was found that the rates of melting and freezing differ,with the former being slower than the latter,but refreezing during the melting season is rather quick.

关键词：土壤温度冻结期青藏高原东北部模拟融化观测数据热力学方程表面模型

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Giant complete automaton for uncertain multiple string matching and its high speed construction algorithm

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Science china(Information {1.) 2011年第8期54卷 1562-1571页

作者： HU Yue 1.2, GAO QingShi 1.2 ,GUO li 2 & {1. PeiFeng 1.1.School of Information Engineering,University of Science and Technology beijing,beijing 1.0083,china 2 institute of Computing Technology,chinese academy of sciences,beijing 1.01.0,china School of Information Engineering University of Science and Technology Beijing Beijing China institute of Computing Technology Chinese Academy of Sciences Beijing China

Multiple string matching is often completed under the presence of U- or V-uncertain-strings,or combinations *** large numbers of strings with U-, V-,and U-V-uncertain-strings,including the interleaving of two or more uncertain strings,is important to thoroughly gathering useful information and detecting harmful *** paper proposes a complete automaton and its high-speed construction algorithm for large-scale U-, V-,and U-V-uncertain multiple strings,including two or more uncertain strings interlaced with one *** maximum number of parallel complete automation of the V-uncertain string is also *** paper reveals that there are two kinds of pretermissions,i.e.,similarly-connected and interlaced-string pretermissions,and that mistake may appear in the matching of the regular expressions,or states in the automaton may increase in number,if the intersection of the U-uncertain strings sets and the homologous subsequent special point in the U-uncertain strings sets are not eliminated from the whole {1..

关键词： multiple string matching U-uncertain-strings V-uncertain-strings U-V-uncertain-strings complete automaton

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Carbon Dioxide Fluxes and Concentrations in a Cotton Field in Northwestern china:Effects of Plastic Mulching and Drip Irrigation

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Pedosphere 2011年第2期21卷 178-185页

作者： li Zhi-Guo Key Laboratory of Oasis Ecology and Desert Environment Xinjiang Institute of Ecology and Geography Chinese Academy ofSciences Urumqi 830011 (China) Graduate University of chinese academy of sciences Beijing 100049 (China) institute of Soil Science Chinese Academy of Sciences Nanjing 210008 (China) Earth system Science Interdiscip{1.nary Center University of Maryland College Park MD 20740 (USA)

In northwestern china, there has been a change from traditional cultivation {1. （TC） with no mulching and flood irrigation to a more modern cultivation {1. （MC） using plastic film mulching with drip irrigation. A field study was conducted to compare soil ＇C02 concentrations and soil surface COs fluxes between TC and MC {1.s during a cotton growing season. CO2 concentrations in the soil profile were higher in the MC {1. （31.7-921.μL L-1. than in the TC {1. （1.275-8994 μL L-1. but the rate of CO2 flux was lower in the MC {1.. Possible reasons for this included decreased gas diffusion and higher soil moisture due to the mulching cover in the MC {1., and the consumption of soil CO2 by weathering reactions. Over the whole cotton growing season, accumulated rates of CO2 flux were 300 and 394 g C m-2 for the MC and TC {1.s, respectively. When agricultural practices were converted from traditional cultivation to a plastic film mulching {1., soil CO2 emissions could be reduced by approximately 1.0 g C m-2 year-1.in agricultural lands in arid and/or semi-arid areas of northern and northwestern china.

关键词： agricultural practice carbon cycle greenhouse gas emission soil respiration weathering reaction

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Nonlinear local Lyapunov exponent and atmospheric predictability research

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Science china Earth {1. 2006年第10期49卷 1111-1120页

作者： CHEN Baohua1. li Jianping1.2 & DING Ruiqiang2 1. College of Atmospheric {1., Lanzhou University, Lanzhou 730000, china 2. State Key Laboratory of Numerical Modeling for Atmospheric Science and Geophysical Fluid Dynamics (LASG), institute of Atmospheric Physics, chinese academy of sciences, beijing 1.0029, china College of Atmospheric sciences Lanzhou University Lanzhou China State Key Laboratory of Numerical Modeling for Atmospheric Science and Geophysical Fluid Dynamics (LASG) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

Because atmosphere itself is a nonlinear {1. and there exist some problems using the linearized equations to study the initial error growth, in this paper we try to use the error nonlinear growth theory to discuss its evolution, based on which we first put forward a new concept: nonlinear local Lyapunov exponent. It is quite different from the classic Lyapunov exponent because it may characterize the finite time error local average growth and its value depends on the initial condition, initial error, variables, evolution time, temporal and spatial scales. Based on its definition and the at-mospheric features, we provide a reasonable algorithm to the exponent for the experimental data, obtain the atmospheric initial error growth in finite time and gain the maximal prediction time. Lastly, taking 500 hPa height field as example, we discuss the application of the nonlinear local Lyapunov exponent in the study of atmospheric predictability and get some reliable results: atmospheric predictability has a distinct spatial structure. Overall, predictability shows a zonal distribution. Prediction time achieves the maximum over tropics, the second near the regions of Antarctic, it is also longer next to the Arctic and in subtropics and the mid-latitude the predictability is lowest. Particularly speaking, the average prediction time near the equation is 1. days and the maximum is located in the tropical Indian, Indonesia and the neighborhood, tropical eastern Pacific Ocean, on these regions the prediction time is about two weeks. Antarctic has a higher predictability than the neighboring latitudes and the prediction time is about 9 days. This feature is more obvious on Southern Hemispheric summer. In Arctic, the predictability is also higher than the one over mid-high latitudes but it is not pronounced as in Antarctic. Mid-high latitude of both Hemispheres (30°S―60°S, 30°―60°N) have the lowest predictability and the mean prediction time is just 3―4 d. In addition, predictab

关键词： nonlinear, local, Lyapunov exponent, atmospheric predictability, maximal prediction time.

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An Agent-based Model of a Capitalist Economy

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systems Science and systems Engineering 2002年第3期11卷 319-327页

作者： ZHANG li-jun, CHENG Dai-zhan{1. of systems Science, chinese academy of sciences, beijing 100080, china institute of {1.s Science Chinese Academy of Sciences Beijing 100080 China

In this paper we investigate the stabilizing role of taxation in an agent based model of a capitalist economy. The model may be considered as a control system with taxation as the control. But it differs from conventional model of control systems. It has some significant characters of complex systems. The system is described and studied by combining the mathematical formulas with computer simulations. Several related concepts as ″output″ and ″control″ etc. are reconsidered from new view-points. Via this problem we explore some phenomenon in controlled complex systems.

关键词： agent capitalist economy emergence taxation feedback

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Zijinshan-Bitian Cu-Au-Mo orefield, SW Fujian——An example of gold-rich PCS zoning

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chinese Science Bulletin 1999年第S2期44卷 134-135页

作者： QI Jianzhong~1, li Zhaonai~2, ZHANG Dequan~3, FANG Xiheng~4 and XIAO Huiliang~1 1. Nanjing institute of Geology and Mineral Resources, chinese academy of Geological sciences, Nanjing 210016, china 2. institute of Geology, chinese academy of Geological sciences, beijing 100037, china 3. institute of Mineral Deposits, chinese academy of Geological sciences, beijing 100037, china 4. institute of Geology, Ministry of Nuclear Industry, beijing 100013, china Nanjing institute of Geology and Mineral Resources Chinese Academy of Geological Sciences Nanjing 210016 China institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China institute of Mineral Deposits Chinese Academy of Geological Sciences Beijing 100037 China institute of Geology Ministry of Nuclear Industry Beijing 100013 China

THE Zijinshan-Bitian Cu-Au-Mo orefield is spread to north of the Shanghang County, SW *** geological structure it is located at the plunging end of NE-trending Xuanhe anticlinorium, in the NE rim ofthe NW trending Shanghang volcano-sedimentary basin. Orefield basement is composed of the Archean-Middle Proterozoic low-grade metamorphic rock formations, containing marine basic metavolcanic sequenses. Lower Cretaceous subaerial volcanic rocks of andesite-trachy andesite-rhyolite composition fill inthe volcano-sedimentary basin. Pre-mineralization granitic batholith dated 1.5Ma（Rb-Sr）and 1.7Ma（U-Pb） occupies the axial part of the plunging anticlinorium, which was regarded as crust-remelting typegranitoids. Mineralization-affiliated subvolcanic dacite porphyrite, co-volcanic granodiorite and quartzdiorite porphyrite （1.2.2 Ma（Rb-Sr）, Sr1./sub> = 0.708 9） belong to syntactic type in genesis and

关键词： gold-rich porphyre copper system zoning Fujian Zijinshan.

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Influences of double aerial CO_2 concentration on plant root surface area and viability and infection intensity of vesicular-arbuscular mycorrhizal fungi

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chinese Science Bulletin 1999年第1期44卷 63-64页

作者： wang Xingfen, {1. Shiyi, BAI Kezhi KUANG Tingyuninstitute of Botany, chinese academy of sciences, beijing 1.0093, china Corresponding author institute of Botany Chinese Academy of Sciences Beijing China

Using recently developed methods for root research, an investigation initiated concerning effects of doubled atmospheric CO2 concentration on root surface area and infection of vesicular-arbuscular mycorrhizal （VAM） fungi in seedlings of maize, wheat and soybean. Results showed that doubled CO2 concentration significantly extended root {1. surface area and promoted VAM fungal infection intensity and viability. However, interspecific variation existed in these responses. It is suggested that plant community succession would be changed due to altered characteristics of roots among species in the future climate.

关键词： doubled CO2 concentration root surface area VAM infection plant community succession.

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Phase separation of ploy(ethylene glycol) + n-butanol mixture induced by supercritical CO_2

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chinese Chemical Letters 2007年第6期18卷 738-740页

作者： Min Qiang Hou, Shu Guang liang, Ji Yuan Song, Xiao Yong li, Zhao Fu Zhang, Tao Jiang, Bu Xing Han beijing National Laboratory for Molecular sciences, institute of Chemistry, chinese academy of sciences, beijing 100080, china beijing National Laboratory for Molecular {1. Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

The phase behavior of supercritical (SC) CO2 + PEG 1.00 (PEG with average molecular weight of 1.00 g/mol) + n-butanol system was studied. It was demonstrated that SC CO2 could induce phase separation of PEG 1.00 + n-butanol system under suitable conditions. This hints that SC CO2 has potential applications in the separation of mixtures of PEG + organic compound.

关键词： PEG1.00 CO2 n-Butanol Phase behavior Separation

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