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Science china Earth Sciences 2005年第9期48卷 1501-1509页

作者： CHEN Junfeng1,2. LI Xiubin2.& ZHANG Ming2.1. institute of Remote Sensing & GIS, Peking University, Beijing 100871, china 2. institute of Geographical Sciences and Natural Resources research, Chinese Academy of Sciences, Beijing 100101, china 1. institute of Remote Sensing & GIS Peking University 100871 Beijing China 2. institute of Geographical Sciences and Natural Resources research Chinese Academy of Sciences 100101 Beijing Chin

Impacts of land cover changes on watershed hydrology have been a long-term academic concern with acute dispute. But little attention has been paid to such effects on mesoscale river basins, where the society has a closer link to river hydrology. The present study focuses on a mesoscale river basin, the Suomo Basin that is located on the upper reaches of the Yangtze river. Land covers in the basin in the years 1970, 1986 and 1999 were mapped. A lumped hydrologic model, CHARM, and a distributed hydrologic model, SWAT, were used to model the impacts of both land-cover change and climate variation on river runoff during the past four decades. The results show that the contribution of climate variation to the change of runoff regime makes up 60%―80%, while that of land cover changes only 2.%.

关键词： climate variation, land-cover changes, Suomo Basin, CHARM model, SWAT model.

A three-dimensional k-ε-k_p model in curvilinear coordinates for sediment movement and bed evolution

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Science china(Technological Sciences) 2009年第4期52卷 1090-1100页

作者： SHEN YongMing1 & LIU Cheng2.1 State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 11602., china 2.Pearl river {2. research institute, Guangzhou 510611, china State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116023 China Pearl river hydraulic {2. institute Guangzhou 510611 China

To aim at the substitution of the magnitude and direction of water flow movement near bed for those of bed load transport in solid-liquid two-phase one-fluid model, and to simulate the effect of secondary flow on transverse bed load transport in channel bends and the effect of bed slope on bed load trans- port in a better way, a three-dimensional k-ε-kp solid-liquid two-phase two-fluid model in curvilinear coordinates is solved numerically with a finite-volume method on an adaptive grid for studying wa- ter-sediment movements and bed evolution in a 12.° channel bend. Numerical results show that the trajectories of solid-phase deviate from those of liquid-phase in the channel bend, and the deviation increases with the increase of the particle diameters. The calculated bed deformation by the k-ε-kp model is in better agreement with measured bed deformation than those by one-fluid model. It is proved that the k-ε-kp model can simulate the effect of secondary flow on lateral bed load transport with the higher accuracy than the one-fluid model.

关键词： curvilinear coordinates three-dimensional k-ε-kp model two-fluid model solid-liquid flows channel bend bed load bed evolution tra- jectory

Abnormal gradient microstructure in Cr_3C_2.based cemented carbide

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Journal of Central South University of Technology 2001年第4期8卷 224-227页

作者： ZHANG Li 1,CHEN Shu 2.(1. Powder Metallurgy Factory, Central South University, Changsha 410083, china 2. Changsha research {2. of Mining and Metallurgy, Changsha 410012. china) 1. Powder Metallurgy Factory Central South University 410083 Changsha China 2. Changsha research institute of Mining and Metallurgy 410012 Changsha China

With OLYMPUS PMG3 metallograph, an abnormal three-layer gradient structure, i. e. coarse grain zone, binder enrichment zone and normal structure zone from surface to inner, was observed in Cr3C2.based cemented carbide. In the binder enrichment zone, three different shapes of anomalous coarse carbides were observed. It is shown that the transverse rupture strength can be raised remarkably, up 2..7%from the alloy with abnormal gradient structure by removing the abnormal gradient structure. The results suggested that the abnormal gradient structure in the surface, especially the anomalous coarse carbides in the binder enrichment zone is the main reason for the lower strength

关键词： Cr3C2.based cermet cemented carbide gradient structure microstructure

Global convergence property of s-dependent GFR conjugate gradient method

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Chinese Science Bulletin 1998年第23期43卷 1959-1965页

作者： WANG Changyu 1,2.and ZHANG Yuzhong\+1 1. institute of Operations research in Qufu Normal University, Qufu 2.3165,{2. 2. institute of Applied Mathematics, Chinese Academy of Sciences, Beijing 100080,{2. institute of Operations research Qufu Normal University Qufu China institute of Applied Mathematics Chinese Academy of Sciences Beijing China

An \%S\%_dependent GFR method and a generalized conjugate gradient method are designed. Two estimated values of upper bounds for the ratio of β k to β FR k are given. The two convergence theorems are proved. The global convergent properties of \%s\%_dependent GFR method are obtained adopting several choice strategies of steplength and some results in recent literature are extended.

关键词： steplength linear search global convergence conjugate gradient.

Runoff reduction due to environmental changes in the Sanchuanhe river basin

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International Journal of Sediment research 2008年第2期23卷 174-180页

作者： Guoqing WANG1,Jianyun ZHANG2.Ruimin HE3,Naiqian JIANG4,and Xin'ai JING5 1 Senior Engineer,State Key Laboratory of Hydrology-Water Resources and hydraulic Engineering,Nanjing hydraulic {2. institute,Nanjing 2.0098,china {2. Center for Climate Change,MWR,Nanjing 2.002.,china yellow river institute of hydraulic {2.,Zhengzhou 450003,china 2.Prof.,3 Engineer,State Key Laboratory of Hydrology-Water Resources and hydraulic Engineering,Nanjing hydraulic {2. institute,Nanjing 2.0098,china 4 Prof.,5 Engineer,yellow river institute of hydraulic {2.,Zhengzhou 450003,china [a]Senior Engineer State Key Laboratory of Hydrology-Water Resources and hydraulic Engineering Nanjing hydraulic research {2. Nanjing 2.0098 china research Center for Climate Change MWR Nanjing 2.002. china yellow river {2. of hydraulic research Zhengzhou 450003 china [b]Prof. State Key Laboratory of Hydrology-Water Resources and hydraulic Engineering Nanjing hydraulic research {2. Nanjing 2.0098 china [c]Engineer State Key Laboratory of Hydrology-Water Resources and hydraulic Engineering Nanjing hydraulic research {2. Nanjing 2.0098 china [d]Prof. yellow river {2. of hydraulic research Zhengzhou 450003 china [e]Engineer yellow river {2. of hydraulic research Zhengzhou 450003 china

Recently,runoff in many river basins in china has been ***,the role that climate change and human activities are playing in this decrease is currently of *** this study,we evaluated an assessment method that was designed to quantitatively separate the effects of climate change and human activities on runoff in river ***,we calibrated the SIMHYD rainfall runoff model using naturally recorded hydro-meteorologic data pertaining to the Sanchuanhe river basin and then determined the effects of climate change and human activities on runoff by comparing the estimated natural runoff that occurred during the period in which humans disturbed the basin to the runoff that occurred during the period prior to disturbance by *** results of this study revealed that the SIMHYD rainfall runoff model performs well for estimating monthly *** addition,we found that absolute runoff reductions have increased in response to human activities and climate change,with average reductions of 70.1% and 2..9% in total runoff being caused by human activities and climate change,*** together,the results of this study indicate that human activities are the primary cause of runoff reduction in the Sanchuanhe river basin.

关键词： Sanchuanhe river Hydrological simulation Climate change Human activities Impact

Distribution and characteristics of gravelly soil liquefaction in the Wenchuan M_s 8.0 earthquake

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Earthquake Engineering and Engineering Vibration 2010年第2期9卷 167-175页

作者： Cao Zhenzhong1,Hou Longqing2.Xu Hongmei2.and Yuan Xiaoming1 1. institute of Engineering Mechanics,china Earthquake Administration,Harbin 150080,china 2. East china institute of Technology,Fuzhou 344000,china institute of Engineering Mechanics China Earthquake Administration Harbin 150080 China

In this paper,a distribution map of gravelly soil liquefaction that was caused by the Wenchuan M8.0 earthquake in china is proposed based on a detailed field investigation and an analysis of geological soil profiles. The geological background of the earthquake disaster region is summarized by compiling geological cross sections and borehole logs. Meanwhile,four typical liquefied sites were selected to conduct sample drillings,dynamic penetration tests (DPT),and shear wave velocity tests,to understand the features of liquefied gravelly soil. One hundred and eighteen (118) liquefied sites were investigated shortly after the earthquake. The field investigation showed:(1) sandboils and waterspouts occurred extensively,involving thousands of miles of farmland,12. villages,eight schools and five factories,which caused damage to some rural houses,schools,manufacturing facilities and wells,etc.; (2. the Chengdu plain is covered by a gravelly soil layer with a thickness of 0 m to 541 m according to the geological cross sections; (3) there were 80 gravelly soil liquefied sites in the Chengdu plain,shaped as five belt areas that varied from 2. km to 40 km in length,and about ten gravelly soil liquefied sites distributed within Mianyang area; and (4) the grain sizes of the sampled soil were relative larger than the ejected soil on the ground,thus the type of liquefied soil cannot be determined by the ejected soil. The gravelly soil liquefied sites are helpful in enriching the global database of gravelly soil liquefaction and developing a corresponding evaluation method in further research efforts.

关键词： gravelly soil liquefaction borehole soil profile geological cross section grain size distribution Wenchuan earthquake

Hydrogen isotopic compositions, distributions and source signals of individual n-alkanes for some typical crude oils in Lunnan Oilfield, Tarim Basin, NW china

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Science china Earth Sciences 2005年第8期48卷 1220-1226页

作者： LU Hong1, LI Chao1, SUN Yongge1, PENG Ping’an1 & XIAO Zhongyao2.1. State Key Laboratory of Organic Geochemistry, Guangzhou institute of Geochemistry, Chinese Academy of Sciences, Guangzhou510640, china 2. Tarim {2. institute of Exploration and Development of Petroleum, china Petroleum, Korla 841000, china 1. State Key Laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences 510640 Guangzhou China 2. Tarim research institute of Exploration and Development of Petroleum China Petroleum 841000 Korla China

Isotopic compositions of carbon-bound hydrogen in individual n-alkanes from sev-eral typical crude oil samples from Lunnan Oilfield, Tarim Basin, NW china, were firstly measured using newly developed gas chromatography-thermal conversion-isotope ratio mass spectrometry. The similar range of δ D of individual n-alkanes of crude oils among reservoirs of different geo-logical times reflects that hydrocarbons are all derived from the same marine depositional envi-ronment. Compared to the theoretic value (?150‰) and the reported δ D values (nC13―nC2., ?160‰―?90‰) of individual n-alkanes for Ordovician-sourced crude oils in the Canadian Wil-liston Basin, the hydrogen isotopic composition of individual n-alkanes in crude oils from Lunnan Oilfield is characterized by heavy hydrogen isotopic values (nC12.nC2., ?12.‰―?60‰). In terms of the factors that control the fractionation of hydrogen isotopes, relatively saline deposi-tional environment and higher thermal maturation were attributed to the heavy δ D values of in-dividual n-alkanes in crude oils from Lunnan Oilfield.

关键词： hydrogen isotopes, individual n-alkanes, distribution, hydrocarbon source, Lunnan Oilfield.

Calculating soil moisture by remote sensing and analyzing hydrologic cycle process in the yellow river basin

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Science china(Technological Sciences) 2004年第z1期47卷 1-13页

作者： YANG Shengtian1 & LIU Changming1, 2.1. School of Environmental Sciences, Beijing Normal University, Beijing 100875, china 2. institute of Geographic Science and Natural Resources {2., Beijing 100101, china Beijing Normal Univ Sch Environm Sci Beijing 100875 Peoples R China Inst Geog Sci & Nat Resources Beijing 100101 Peoples R China

Based on the AVHRR pathfinder remote sensing data, soil moisture, precipitation and evaporation during the period of 1982.1998, soil moisture of all layers of soil-profile (0—1 m) in the yellow river basin over the 17 years are calculated by the remote sensing model of calculating soil water. The yellow river basin is divided into seven subcatchments as control sections at the location of six hydrologic stations (Lanzhou, Toudaoguai, Longmen, Sanmenxia, Huayuankou and Lijin). After calculating soil moisture and obtaining runoff data and precipitation data, the dynamical features of hydrological cycle in the yellow river basin are analyzed for the period from 1982.to 1988 using water balance method. The conclusions are as follows: It is feasible to calculate the soil water on the macro-scale, in the soil profile with temporal continuity by means of remote sensing and survey in land. Some values of the key water cycle factors in the yellow river are obtained, which include the annual precipitation of 4000 km3, the evapotranspiration of 3000-3500 km3, and the soil moisture transformation of ?500- 500 km3. Consequently, we analyzed the process of the water cycle in the yellow river over the 17 years, and the results show that the segment upstream of Lanzhou city is a relatively humid region, and the area of internal waters and the reaches of Shanshan is the most desiccated region. Therefore, the runoff in the depth process is intensive and the runoff-generating process is weak in more arid regions.

关键词： the yellow river, soil moisture, remote sensing, hydrologic cycle.

research progress in synthesis and catalysis of polyoxometalates

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Progress in Natural Science:Materials International 2005年第5期15卷 385-394页

作者： GONG Yun1, HU Changwen1* and LIANG Hong2.1. Department of Chemistry, School of Science, the institute for Chemical Physics, Beijing institute of Technology, Beijing 100081,{2. 2. Chemical Industry Press, Beijing 10002.,{2.) Department of Chemistry School of Science the Institute for Chemical Physics Beijing Institute of Technology Beijing 100081 China Chemical Industry Press Beijing 100029 China

Recent progress in the synthetic chemistry and catalysis of polyoxometalates (POMs) is reviewed. The novel POMs and their derivatives emerging in nearly three years (2.02.2.04) are introduced, including POMs with novel structure, POMs-organic hybrid compounds and host-guest complexes. Our review is focused on the elaboration of POMs' supramolecular chemistry.

关键词： polyoxometalates hybrid host-guest structure supramolecule catalysis.

A preliminary study on vegetation-erosion dynamics and its applications

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Science china Earth Sciences 2005年第5期48卷 689-700页

作者： WANG Zhaoyin 1,2., WANG Guangqian 1 , LI Changzhi 1 & WANG Feixin 1 1. Department of hydraulic Engineering, Tsinghua University, Beijing 100084, china 2. International {2. and Training Center on Erosion and Sedimentation, Beijing 100084, china 1. Department of hydraulic Engineering Tsinghua University 100084 Beijing China 2. International research and Training Center on Erosion and Sedimentation 100084 Beijing China

Vegetation-erosion dynamics is a new interdisciplinary science, studying the laws of evolution of watershed vegetation under the action of various ecological stresses. Introducing a qualitative expression of ecological stresses in this paper, the present authors establish the cou- pled differential equations for the vegetation-erosion process and derive a theoretical solution. The model is applied to the Anjiagou watershed on the Loess Pateau and the Xiaojiang water- shed and its sub-watersheds on the Yunnan Plateau. The calculated results agree well with the vegetation development processes. Abstracted from the differential equations the so-called vegetation-erosion chart is worked out, with which we can predict the development trend of vegetation under no human stresses. It is demonstrated that the erosion control is important for vegetation development and reforestation must be a long-term strategy. On the Yunnan Plateau with relatively high precipitation and temperature, vegetation can be greatly improved if erosion is controlled. On the dry and cold Loess Pateau suffering from high rate of soil erosion, however, vegetation can effectively control erosion but erosion reduction exhibits low effectiveness on vegetation development. Vegetation in the area is not stable and management is always needed to maintain the vegetation.

关键词： vegetation-erosion dynamics, human activities, coupled differential equations, erosion control, vigor ofvegetation.