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The impact of vegetation restoration on erosion-induced sediment yield in the middle Yellow River and management prospect

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Science China Earth Sciences 2005年第6期48卷 724-741页

作者： CHEN Hao1, ZHOU Jinxing2, CAI Qiangguo1, YUE Zhongqi3. LU Zhongchen4, LIANG Guanglin1& HUANG Jianguo5 1. Key Laboratory of Water Cycle and Related Land Surface Processes, institute of Geographic Sciences and Natural Resources Re-search, Chinese Academy of Sciences, Beijing 100101, China 2. institute of Forestry, Chinese Academy of Forestry Sciences, Beijing 100091, China 3. department of civil engineering, University of Hong Kong, Hong Kong, China 4. Eco-environmental Research Center, Chinese Academy of Sciences, Beijing 100085, China 5. College of Resources and Environment, Southwest Agricultural University, Chongqing 400716, China Correspondence should be addressed to Chen Hao 1. Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences 100101 Beijing China 2. institute of Forestry Chinese Academy of Forestry Sciences 100091 Beijing China 3. department of civil engineering University of Hong Kong Hong Kong China 4. Eco-environmental Research Center Chinese Academy of Sciences 100085 Beijing China 5. College of Resources and Environment Southwest Agricultural University 400716 Chongqing China

According to the characteristics of water and erosion environments of different natural zones on the Loess Plateau, this paper studies changes of vegetation types, distribution boundaries of forest and grass as well as restoration capacity of vegetation in different natural zones in the middle Yellow River. The annual precipitation of 53. mm is the critical annual pre-cipitation for forest and grass distribution in the middle Yellow River. Among the zonal and azonal environmental factors affecting watershed sediment yield, the intermediate diameter D50 (mm) of suspended load and forest coverage (V, %) play the leading role. Of them the effect weight of forest coverage (V, %) on catchments sediment yield is only 3.4% less than the role of the intermediate diameter (D50, mm), they are almost the same. To effectively control soil erosion in semiarid, especially in hilly-gullied areas and make sediment transport modulus reduce to less than 6000 t/km2, it is rather difficult by merely relying on natural restoration of forest. In the process of cultivated land conversion into forest land and grassland, measures suiting local conditions should be adopted in tree species selection and artificial afforestation (grass planting) based on management with biological measures for slopeland and engineering measures for hilly-gullied areas, so that watershed forest coverage in key counties can reach at least over 3.%.Compared with the standard period of precipitation prior to the 1960s, with the decrease of an-nual precipitation at various periods, plant productivities decline to different degrees under natural conditions. The main reason accountable for the low survival rate of new seedlings and grass over years is due to precipitation decrease. In light with regression models of annual pre-cipitation and natural vegetation productivities, it is possible to obtain estimated values of wa-tershed natural vegetation productivity and eco-water consumption needed for the restoration to

关键词： vegetation restoration, eco-water requirement, watershed sediment yield, the middle Yellow River.

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Bipolar charged aerosol agglomeration and collection by a two-zone agglomerator

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Journal of Environmental Sciences 2001年第3期13卷 276-279页

作者： XIANG Xiao dong 1, CHEN Bao zhi 1, COLBECK I 2 (1. School of Resource and civil engineering, Northeastern University, Shenyang 110006, China. 2. institute for Environmental Research, {3. of Biological and Chemical Sciences, University of Es School of Resource and civil engineering Northeastern University Shenyang 110006 China.

In older to collect fine particles more efficiently, a new-type electrostatic agglomerator with two zones was developed. The distinguishing feature of this electrostatic agglomerator is that the particles are bipolarly charged and coagulated in the same alternating electric field simultaneously. The silica flour with 2 fun mass median diameter and the smoke from burning wood powder were used as test aerosol. The comparison experimental results have shown that when the mean electric field is 4 kV/cm the collection efficiency of the new electrostatic agglomerator was 98.2% for silica flour and 67.4% for wood powder smoke, Under the same experimental condition. the collection efficiency of the electrostatic agglomerator with three zones was 97.4% for collecting silica flour and the collection efficiency of the electrostatic precipitator was 56.3. for wood powder smoke.

关键词： charged particle agglomeration alternating electric field electrostatic agglomerator (EA) electrostatic precipitator (ESP) collection efficiency

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Spatial Distribution of Land Cover and Vegetation Activity along Topographic Gradient in an Arid River Valley, SW China

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Journal of Mountain Science 2009年第3期6卷 274-285页

作者： LIU Wen XU Xianli LUO Jiancheng SHEN Zhanfeng ZHONG Qiuhai department of Automatic Control School of Automation Beijing Institute of Technology Beijing 100081 China State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China Centre for Hydrology Micrometeorology and Climate Change Department of Civil and Environmental Engineering University College Cork Cork Ireland

Anthropogenic activities have become more and more important in characterizing the landscape, but their impacts are still restricted by natural environments. This paper discusses the interactions of anthropogenic activity, vegetation activity and topography through describing the spatial distribution of land cover and vegetation activity (represented by Normalized Difference Vegetation Index, NDVI) along topographic gradient in a mountainous area of southwestern China. Our results indicate that the existing landscape pattern is controlled by anthropogenic activities as well as topographic factors. Intensive anthropogenic activities mainly occur in areas with relatively low elevation, gentle and concave slopes, as these areas are easy and convenient to attain for human. Because of the destruction by human, some land cover types (mainly grassland and shrub) are only found in relatively harsher environments. This study also finds that topographic wetness index (W) used in other places only reflects runoff generation capacity, but not indicate the real spatial pattern of soil water content in this area. The relationships between NDVI and W, and NDVI and length slope factor (LSF) show that runoff and erosion have complex effects on vegetation activity. Greater values of W and LSF will lead to stronger capacity to produce runoff and transport sediment, and thereby increase soil water content and soil deposition, whereas beyond a certain threshold runoff and erosion are so strong that they would destruct vegetation growth. This study provides information needed to successfully restore native vegetation, improve land management, and promote sustainable development in mountainous areas, especially for developing regions.

关键词： Vertical distribution of land cover Anthropogenic activity Vegetation activity Environmental variability China

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Intelligent optimization of the structure of the large section highway tunnel based on improved immune genetic algorithm

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Journal of Pharmaceutical Analysis 2009年第3期21卷 163-166页

作者： Hai-tao Bo1,Xiao-feng Jia2,Xiao-rui Wang11.School of civil engineering and Mechanics,Huazhong University of Science and technology, Wuhan 43.074 2.{3. of Chemistry and Bioengineering,Nanyang institute of technology,Nanyang 473.04,China. School of civil engineering and Mechanics Huazhong University of Science and Technology Wuhan 430074 China department of Chemistry and Bioengineering Nanyang Institute of Technology Nanyang 473004 China

As in the building of deep buried long tunnels,there are complicated conditions such as great deformation,high stress,multi-variables,high non-linearity and so on,the algorithm for structure optimization and its application in tunnel engineering are still in the starting stage. Along with the rapid development of highways across the country,it has become a very urgent task to be tackled to carry out the optimization design of the structure of the section of the tunnel to lessen excavation workload and to reinforce the support. Artificial intelligence demonstrates an extremely strong capability of identifying,expressing and disposing such kind of multiple variables and complicated non-linear relations. In this paper,a comprehensive consideration of the strategy of the selection and updating of the concentration and adaptability of the immune algorithm is made to replace the selection mode in the original genetic algorithm which depends simply on the adaptability value. Such an algorithm has the advantages of both the immune algorithm and the genetic algorithm,thus serving the purpose of not only enhancing the individual adaptability but maintaining the individual diversity as well. By use of the identifying function of the antigen memory,the global search capability of the immune genetic algorithm is raised,thereby avoiding the occurrence of the premature phenomenon. By optimizing the structure of the section of the Huayuan tunnel,the current excavation area and support design are adjusted. A conclusion with applicable value is arrived at. At a higher computational speed and a higher efficiency,the current method is verified to have advantages in the optimization computation of the tunnel project. This also suggests that the application of the immune genetic algorithm has a practical significance to the stability assessment and informationization design of the wall rock of the tunnel.

关键词： immune genetic algorithm tunnel super-large section optimization

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DEWATERING MEASURE APPLIED TO SOLVE LANDSLIDE PROBLEM IN EXPANSIVE SOIL AREA

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安徽建筑工业学院学报（自然科学版） 1995年第1期3卷 27-33页

作者： Tao Taijiang Xe Yiping Liao Jichuan (civil engineering department) (Simashan Managing department) (Hefei University of technology)

ＤＥＷＡＴＥＲＩＮＧＭＥＡＳＵＲＥＡＰＰＬＩＥＤＴＯＳＯＬＶＥＬＡＮＤＳＬＩＤＥＰＲＯＢＬＥＭＩＮＥＸＰＡＮＳＩＶＥＳＯＩＬＡＲＥＡ￥ＴａｏＴａｉｊｉａｎｇ；ＸｅＹｉｐｉｎｇ；ＬｉａｏＪｉｃｈｕａｎ（ＣｉｖｉｌＥｎｇ... 详细信息

ＤＥＷＡＴＥＲＩＮＧＭＥＡＳＵＲＥＡＰＰＬＩＥＤＴＯＳＯＬＶＥＬＡＮＤＳＬＩＤＥＰＲＯＢＬＥＭＩＮＥＸＰＡＮＳＩＶＥＳＯＩＬＡＲＥＡ￥ＴａｏＴａｉｊｉａｎｇ；ＸｅＹｉｐｉｎｇ；ＬｉａｏＪｉｃｈｕａｎ（ＣｉｖｉｌＥｎｇｉｎｅｅｒｉｎｇＤｅｐａｒｔｍｅｎ...

关键词： Expansive soil Landslide Dewatering measure.

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A NEW NUMERICAL METHOD FOR GROUNDWATER FIOW AND SOLUTE TRANSPORT USING VELOCITY FIELD

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Journal of Hydrodynamics 2008年第3期20卷 356-364页

作者： ZHANG Qian-fei LAN Shou-qi WANG Yan-ming XU Yong-fu School of Naval Architecture Ocean and Civil Engineering Shanghai Jiaotong University Shanghai 200030China Shanghai Municipal engineering Design institute Shanghai 200092 China department of Geotechnical engineering Tongji University Shanghai 200092 China

A new numerical method for groundwater flow analysis was introduced to estimate simultaneously velocity vectors and water pressure head. The method could be employed to handle the vertical flow under variably saturated conditions and for horizontal flow as well. The method allows for better estimation of velocities at the element nodes which can be used as direct input to transport models. The advection-dispersion process was treated by the Eulerian-Lagrangian approach with particle tracking technique using the velocities at FEM nodes. The method was verified with the classical one dimensional model and applied to simulate contaminant transport process through a slurry wall as a barrier to prevent leachate pollution from a sanitary landfill.

关键词： groundwater flow solute transport velocity vectors finite element method Eulerian-Lagrangian approach particletracking technique

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The Erythropoietin Receptor: Dimerization and Intracellular Signal Transduction

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中国实验血液学杂志 1996年第3期4卷 229-235页

作者： WU Hong Harvey F Lodish(Whitehead institute for Biomedical Research, Nine Cambridge Center Cambridge MA 02142 usa) (department of Biology,{3. Cambridge MA 0213. usa)

Erythropoietin (EPO), a 3. kD glycopro-tein, is the principal growth factor regulating theproduction of circulating erythrocytes; EPO isessential for committed CFU - E erythroid pro-genitors to divide several times and then to dif-ferentiate into erythrocytes. Like most receptorsfor hematopoietic growth factors, the erythro-poietin receptor (EPO - R) is a type I trans-membrane protein and a member of the cytokinereceptor superfamily. These receptors containfour conserved cysteines and a Trp - Ser - X -

关键词： erythropoietin erythropoietin receptor dimerization signal transduction

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非保守力与非完整约束对Lagrange系统Noether对称性的影响

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物理学报 2004年第3期53卷 661-665页

作者：张毅梅凤翔苏州科技学院土木工程系苏州215011 北京理工大学理学院北京100081

研究非保守力和非完整约束对Lagrange系统的Noether对称性的影响 .Lagrange系统受到非保守力或非完整约束作用时 ,系统的Noether对称性和守恒量都会发生变化 .原有的一些Noether对称性消失了 ,一些新的Noether对称性产生了 ,在一定条件... 详细信息

研究非保守力和非完整约束对Lagrange系统的Noether对称性的影响 .Lagrange系统受到非保守力或非完整约束作用时 ,系统的Noether对称性和守恒量都会发生变化 .原有的一些Noether对称性消失了 ,一些新的Noether对称性产生了 ,在一定条件下 ,一些Noether对称性仍保持不变 .分别给出系统的Noether对称性以及守恒量保持不变的条件。

关键词：非保守力非完整约束 Lagrange系统 Noether对称性哈密顿作用量坐标变换分析力学

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Extraction and Characterization of Humic Acids and Humin Fractions from a Black Soil of China

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Pedosphere 2005年第1期15卷 1-8页

作者： XING Bao-Shan, LIU Ju-Dong, LIU Xiao-Bing and HAN Xiao-ZengNortheast institute of Geography and Agro-ecology, Chinese Academy of Sciences, Harbin 150040 (China). department of Plant, Soil and Insect Sciences, University of massachusetts, MA 01003.({3.) Northeast institute of Geography and Agro-ecology Chinese Academy of Sciences Harbin 150040 （China）. department of Plant Soil and Insect Sciences University of massachusetts MA 01003.（usa）

Twenty-three progressive extractions were performed to study individual humic acids (HAs) and humin fractions from a typical black soil (Mollisol) in Heilongjiang Province, China using elemental analysis and spectroscopic techniques. After 23.HA extractions the residue was separated into high and low organic carbon humin fractions. HA yield was the highest for the first extraction and then gradually decreased with further extractions. Organic carbon (OC) of the humin fractions accounted for 58% of total OC even after 23.successive HA extractions. In addition, the atomic C/H ratio decreased during the course of extraction while C/O increased; the E4/E6 ratio from the UV analysis decreased with further extraction while E2/E3.increased; the band assigned to aliphatic carbon (293. cm-1) in the diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) spectra gradually increased with progressive extraction; the calculated ratio of the sum of aromatic carbon peak heights to that of aliphatic carbon

关键词： elemental composition humic acid humin soil organic matter spectroscopic analysis

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Study on the squeezing effect of open-ended pipe piles

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Journal of Pharmaceutical Analysis 2009年第3期21卷 155-159,171页

作者： Yan-er Lu1,Jun-jie Zheng1,Jian-hua Yin21.institute of Geotechnical and Underground engineering,Huazhong University of Science and technology,Wuhan 43.074,China 2.{3. of civil and Structural engineering,the Hong Kong Polytechnic University,Hong Kong,China. institute of Geotechnical and Underground engineering Huazhong University of Science and Technology Wuhan 430074 China department of civil and Structural engineering Hong Kong Polytechnic University Hong Kong Hong Kong

During the installation of a pipe pile,the soil around the pile will be squeezed out. This paper deals with this squeezing effect of open-ended pipe piles using the cylindrical cavity expansion theory. The characteristics of soil with different tension and compression moduli and dilation are involved by applying the elastic theory with different moduli and logarithmic strain. The closed-form solutions of the radius of the plastic region,the displacement of the boundary between the plastic region and the elastic region and the expansion pressure on the external surface of the pipe piles are obtained. When obtaining these solutions,the soil plug in the open-ended pipe pile is considered by employing an incremental filling ratio to quantify the degree of soil plugging. Moreover,the effects of the ratio of tension and compression moduli,angle of dilation and incremental filling ratio on the radius of the plastic region and the expansion pressure on the external surface of the pipe pile are investigated. The parametric analyses show that it is necessary and important to consider the difference between the tension modulus and compression modulus,dilation angle and incremental filling ratio for studying the squeezing effect of open-ended pipe pile installation. It is concluded that the analytical solutions presented in this paper are suitable for studying the squeezing effect of open-ended pipe piles.

关键词： open-ended pipe pile squeezing effect ratio of tension and compression moduli incremental filling ratio

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