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Assessment of soil erosion and sediment delivery ratio using remote sensing and GIS:a case study of upstream Chaobaihe River catchment, north china

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International Journal of Sediment Research 2008年第2期23卷 167-173页

作者： Weifeng ZHOU1 and Bingfang WU2 1 Doctor candidate,graduate school of the chinese academy of sciences(CAS),beijing 100039,{7. 2 Prof.,Institute of Remote Sensing Applications,chinese academy of sciences(CAS),beijing 100101,{7. [a]Doctor candidate graduate school of the chinese academy of sciences(CAS) beijing 100039 china [b]Prof. Institute of Remote Sensing Applications chinese academy of sciences(CAS) beijing 100101 china

Soil erosion in catchment areas reduces soil productivity and causes a loss of reservoir *** parametric models have been developed to predict soil erosion at drainage basins,hill slopes and field *** well-known Universal Soil Loss Equation(USLE) represents a standardized *** reservoir,which sits on Chaobaihe River,is the main surface source of drinking water for beijing,the capital of *** and soil loss are the main reasons for sediment to enter a *** yield is assessed using a version of the universal soil loss equation modified by chinese *** year 2001 and 2002 data for factors in the equation are obtained from remote sensing or collected to form an analysis *** factors are computed and mapped using Geographic Information System *** on the complex database,the modified model is *** pixel-based computing the sediment yield per hydrological unit is *** model does not consider sediment deposition occurring on *** soil loss is often higher than the sum of those measured at catchment *** sediment delivery ratio(SDR) per hydrological unit is also *** study analyzes the main contributions of sediment yields on sub-basins of the Chaobaihe River to the Miyun Reservoir,and discusses the possible reasons for the difference between SDRs in 2001 and 2002 at different *** result shows that in the upper basin of the Miyun Reservoir,in 2001 the area of erosion that could be neglected was 8,202.7. km2,the area of low erosion 3,269.59 km2,the area of moderate erosion 3,400.97.km2,the area of high erosion 436.89 km2,the area of strong erosion 52.19 km2 and the area of severe erosion 3.13 *** highest soil loss was 7.,353 t/*** in Fengning County in 2001,followed by 64,418 t/*** by Chicheng County in *** SDR in 2002 was lower than that in *** main reasons are the decreasing rainfall erosivity and total runoff.

关键词： Modified USLE Gross erosion Sediment delivery ratio

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RADIAL BASIS FUNCTION INTERPOLATION IN SOBOLEV SPACES AND ITS APPLICATIONS

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Journal of Computational Mathematics 2007年第2期25卷 201-210页

作者： Manping Zhang (school of Mathematical sciences,Fudan University,Shanghai 200433,china Institute of Computational Mathematics,chinese academy of sciences,beijing 100080,china school of Mathematical sciences Fudan University Shanghai 200433 China Institute of Computational Mathematics Chinese Academy of Sciences Beijing 100080 China

In this paper we study the method of interpolation by radial basis functions and give some error estimates in Sobolev space H^k（Ω）（k 〉 1）. With a special kind of radial basis function, we construct a basis in H^k（Ω） and derive a meshless method for solving elliptic partial differential equations. We also propose a method for computing the global data density.

关键词： Sobolev space Radial basis function Global data density Meshless method

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Assessing the Carrying Capacity of Tourist Resorts: An Application of Tourists’ Spatial Behavior Simulator Based on GIS and Multi-Agent System

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Wuhan University Journal of Natural sciences 2005年第4期10卷 779-784页

作者： ZHANG Ren-jun 1,2 1. Institute of Mountain Hazards and Environment, chinese academy of sciences, Chengdu 610041, Sichuan, china 2. graduated school of the chinese academy of sciences, beijing 100039, china chinese academy of sciences Institute of Mountain Hazards and Environment Chengdu Sichuan China (GRID:grid.9227.e) (ISNI:***) graduated school of the chinese academy of sciences Beijing China (GRID:grid.9227.e) (ISNI:***)

Based on the study of visitors' individual spatial behaviors, a tourists'spatial behavior simulator (TSBS) to assess the carrying capacity of tourist resorts was developed,TSBS employs GIS (Geographic Information System) to manage the spatial data,and Multi-Agent systemto simulate the actions of individual visitors. By utilizing TSBS, visitors' travel patterns such aslocation, cost, and state can be analyzed and predicted. Based on this analysis and prediction, themodel of assessing the carrying capacity of resorts is built. Our results show that TSBS will be aneffective tool to accurately assess the carrying capacity of tourist resorts.

关键词： tourist resort carrying capacity TSBS GIS Multi-Agent simulator

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Nonlinear interactions between gravity waves and background winds

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Progress in Natural Science:Materials International 2007年第6期17卷 639-644页

作者： Liu Xiao1,2 and Xu Jiyao1(1. State Key Laboratory for Space Weather, Center for Space Science and Applied Research, chinese academy of sciences, beijing 100080, china 2. graduate University of chinese academy of sciences, beijing 100039, china) [a]State Key Laboratory for Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China [b]graduate University of chinese academy of sciences Beijing China

Using the nonlinear propagating gravity waves (GW) model in the two-dimensional compressible atmosphere and the linear GW theory, the process of GW propagation in different background winds, e.g. the direction of the background wind is opposite to (dead wind) or the same as (tail wind) the direction of the horizontal phase velocity of GW, is studied. The results show that the dead wind prolongs the vertical wavelength and accelerates GW propagation. Therefore, GW propagates up to a higher height becomes instable in a short time and eventually induces an inverse jet flow. Then, the vertical wavelength is becoming short due to the nonlinear interactions between GW and the inverse jet flow. The vertical wavelength and group velocity decrease after GW propagates into the tail wind. The initial instable time is delayed. Although most of GW is trapped in the instable region, some of GW propagates above the instable region. Compared with GW propagation in the tail wind, the nonlinear interactions between GW and the dead wind are also strong. In contrast, the linear GW theory predicts that GW can propagate freely in the dead wind. The vertical wavelength simulated by the nonlinear numerical model is different from that predicted by the linear theory greatly after GW propagates into the dead wind.

关键词： gravity waves background winds vertical group velocity vertical wavelength nonlinear interactions.

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Algebraically explicit analytical solu-tions for the unsteady non-Newtonian swirling flow in an annular pipe

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Science china(Physics,Mechanics & Astronomy) 2006年第4期49卷 396-400页

作者： CAI Ruixian1 & GOU Chenhua1,2 1. Institute of Engineering Thermophysics, chinese academy of sciences, beijing 100080, china 2. graduate school, chinese academy of sciences, beijing 100080, china 1. Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing 100080 China 2. graduate school Chinese Academy of Sciences Beijing 100080 China

This paper presents two algebraically explicit analytical solutions for the incompressible unsteady rotational flow of Oldroyd-B type in an annular pipe. The first solution is derived with the common method of separation of variables. The second one is deduced with the method of separation of variables with addition developed in recent years. The first analytical solution is of clear physical meaning and both of them are fairly simple and valuable for the newly developing computational fluid dynamics. They can be used as the benchmark solutions to verify the applicability of the existing numerical computational methods and to inspire new differencing schemes, grid generation ways, etc. Moreover, a steady solution for the generalized second grade rheologic fluid flow is also presented. The correctness of these solutions can be easily proven by substituting them into the original governing equation.

关键词： analytical solution, Oldroyd-B type fluid, swirling flow, non-Newtonian.

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Improvement of different source function expressions in SWAN model for the Bohai Sea

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Progress in Natural Science:Materials International 2005年第8期15卷 720-724页

作者： YIN Baoshu1*, YANG Dezhou1, SHA Rina 1,2 and CHENG Minghua1(1. Institute of Oceanology, chinese academy of sciences, Qingdao 26607., china 2. graduate school of the chinese academy of sciences, beijing 100039, china) Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China. graduate school of the chinese academy of sciences Beijing 100039 China

The simulating wave nearshore （SWAN） wave model has been widely used in coastal areas, lakes and estuaries. However, we found a poor agreement between modeling results and measurements in analyzing the chosen four typical cases when we used the default parameters of the source function formulas of the SWAN to make wave simulation for the Bohai Sea. Also, it was found that at the same wind process the simulated results of two wind generation expressions （Komen, Janssen） demonstrated a large difference. Further study showed that the proportionality coefficient α in linear growth term of wave growth source function plays an unperceived role in the process of wave development. Based on experiments and analysis, we thought that the coefficient α should change rather than be a constant. Therefore, the coefficient α changing with the variation of friction velocity U*was introduced into the linear growth term of wave growth source function. Four weather processes were adopted to validate the improvement in the linear growth term. The results from the improved coefficient α agree much better with the measurements than those from the default constant coefficient α. Furthermore, the large differences of results between Komen wind generation expression and Janssen wind generation expression were eliminated. We also experimented with the four weather processes to test the new white-capping mechanisms based on the cumulative steepness method. It was found that the parameters of the new white-capping mechanisms are not suitable for the Bohai Sea, but Alkyon's white-capping mechanisms can be applicable to the Bohai Sea after amendments, demonstrating that this improvement of parameter α can improve the simulated results of the Bohai Sea.

关键词： waves SWAN model wave growth source function new proportionality coefficient formula.

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Some characteristics of the atmosphere during an adiabatic process

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Progress in Natural Science:Materials International 2006年第6期16卷 644-648页

作者： GAO Li, LI Jianping and REN Hongli (LASG, Institute of Atmospheric Physics, chinese academy of sciences, beijing 100029, china graduate school of chinese academy of sciences, beijing 100049, china National Climate Center, Laboratory of Climate Studies, china Meteorological Administration, beijing 100081, china) [a]LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China [b]graduate school of chinese academy of sciences Beijing China [c]National Climate Center Laboratory of Climatic Studies China Meterological Administration Beijing China

Some important characteristics of the atmosphere during an adiabatic process are investigated, which include the invariability of atmospheric entropy range and local surface potential temperature, the conservation of the atmospheric mass intervened between any isentropic surface and the ground, and the isentropic surface intersecting with the ground. The analysis shows that the atmospheric reference state (ARS) for investigation on available potential energy (APE) should be defined objectively as the state which could be approached from the existing atmosphere by adiabatic adjustment, and be related to initial atmospheric state before adjustment. For the initial atmosphere state at any time, its corresponding ARS is different from the one at another time. Based on the above-mentioned conclusions, the reference state proposed by Lorenz cannot be obtained physically, so a new conception, the conditional minimum total potential energy, is put forward in order to objectively investigate atmospheric APE.

关键词： available potential energy adiabatic isentropic surface atmospheric reference state conditional minimum total potential energy.

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Research on applying physical chaos generator to spacecraft information security

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Science china(Technological sciences) 2009年第5期52卷 1463-1470页

作者： ZHAO HePing State Key Laboratory of Information Security,graduate University of chinese academy of sciences,beijing 100049,china china academy of Space Technology,beijing 100094,china State Key Laboratory of Information Security Graduate University of Chinese Academy of Sciences Beijing 100049 China china academy of Space Technology Beijing 100094 China

The effectiveness of a short-length message extension method based on physical chaos generator was analyzed and the entropy of the extended message was calculated in this *** analysis demon-strated that with the mentioned method the entropy of short-length messages,which are repeatedly used in spacecraft data systems,is obviously increased,and the security of transmission is enhanced as *** paper also presented an improvement of the protocol for secret key agreement presented by *** and *** of depending on characteristics of communication channel,this method takes advantage of the random data produced by physical chaos generator to preset the initial parameters of the procedure on both sides of communication,so that the procedure and quantity of cipher key can be precisely *** method can be used to cipher key management of se-cure communication between long life-span spacecraft and ground system.

关键词： physical chaos generator spacecraft information security message extension cipher key management

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MicroRNA (miR396) negatively regulates expression of ceramidase-like genes in Arabidopsis

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Progress in Natural Science:Materials International 2009年第6期19卷 781-785页

作者： Dongmei Liu a,b, Diqiu Yu a, a Xishuangbanna Tropical Botanical Garden, chinese academy of sciences, Kunming 650223, china b graduate school of the chinese academy of sciences, beijing 100049, china [a]Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences Kunming 650223 China [b]Graduate School of the Chinese Academy of Sciences Beijing 100049 China

MicroRNAs (miRNAs) are 21-23 nucleotide (nt), endogenous RNAs that regulate gene expression by targeting mRNAs for direct cleavage or translational repression in plants. In Arabidopsis, miR396 is encoded by two different loci (MIR396a and MIR396b) and sequence analysis suggests it may target three ceramidase-like genes (Atceramidase-like 1, Atceramidase-like 2 and Atceramidase-like 3). To demonstrate the biological function of miR396, we inserted the synthetic precursors, MIR396a or MIR396b, under the control of the enhanced cauliflower mosaic virus (CaMV) 35S promoter, into a plant transformation vector (pOCA30) and transformed the constructs into Arabidopsis. The promoter increased miR396 levels by more than 2-fold, indicating appropriate maturation of the synthetic precursor MIR396a or MIR396b transcript in transgenic plants. Microarray analysis showed that the transcript levels of two ceramidase-like genes (Atceramidase-like 1, Atceramidase-like 2) were decreased by more than 2-fold and lactosylceramide 4-a-galactosyltransferase increased by more than 2-fold in transgenic plants compared with the empty vector-transformed plants. Northern blot analysis showed that the mRNA levels of the two ceramidase-like genes were significantly reduced in transgenic plants. These results indicated that miR396 probably plays a crucial role in the ceramide metabolism pathway by negatively regulating the expression of ceramidase-like genes in Arabidopsis.

关键词： miR396 miR396 precursor Ceramidase Ceramide

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Research on Jiuquan-Jiayuguan-Yumen Region's Dynamic Changing of Urbanization Based on Self-Organizing Model

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chinese Journal of Population,Resources and Environment 2005年第3期3卷 22-28页

作者： Li Ming 1,2 & Fang Chuanglin 2 1 graduate school of the chinese academy of sciences, beijing 100039,china 2 Institute of Geographical sciences and Natural Resources Research, CAS, beijing 100101, china graduate school of the chinese academy of sciences Beijing 100039 China Institute of Geographical sciences and Natural Resources Research CAS Beijing 100101 China

Based on the self-organizing modeling principle in the dissipative structure theory, the paper regards the migration coupling between the regions as the influence factor to create the model of regional urbanization simulation and prediction, which is more practical to simulate the space-time and dynamic evolvement characteristics of regional urbanization level. According to the historical data about the population and urbanization of Jiuquan, Jiayuguan andYumen cities, the past 50 years' dynamic evolvement trend is simulated and the following 50 years' dynamic evolvement trend is predicted with the urbanization dynamic evolvement model based on the self-organizing model. The analysis of effective factors such as economic increase, resources exploitation, ecosystem construction, traffic location, national policies, population migration are given, then the reasons of the dynamic evolvement differences of the three cities' urbanization are drawn. The study suggests that the self-organizing model is fit for the simulation of Jiuquan-Jiayuguan-Yumen regional urbanization level in the past 50 years, and the departure between the stimulant and the actual data is under 5%, so it can be used to predict the urbanization future of the three cities. The predicted results show that the regional population will reach 1.07. million and the regional urbanization level will be 7..56%.

关键词： self-organizing urbanization dynamic evolvement Jiuquan-Jiayuguan-Yumen region

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