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An ecological hydraulic radius approach to estimate the instream ecological water requirement

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Progress in Natural Science:Materials International 2007年第3期17卷 320-327页

作者： LIU Changming and MEN Baohui ( key laboratory of {2. Cycle and Related Land Surface Process, Institute of Geographical sciences and Natural resources Research, Chinese Academy of sciences, Beijing 100101, china key laboratory of {2. and Sediment sciences, Ministry of Education & {2. sciences College, Beijing Normal university, Beijing 100875, china Department of Hydraulic and hydropower engineering, North china Electric Power university, Beijing 102.06, china) [a]key laboratory of {2. Cycle and Related Land Surface Process Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China [b]key laboratory of {2. and Sediment sciences Ministry of Education & Water Sciences Gllege Beijing Noirnal University Beijing China [c]Departhent of Hydraulic and hydropower engineering North China Elecfric Power University Beijing China

This essay defines the concepts of ecological flow velocity as well as ecological hydraulic radius (EHR) and proposes an ecological hydraulic radius approach (EHRA) which considers both the watercourse information (including hydraulic radius, roughness coefficient and hydraulic gradient) and the required stream velocity necessary for maintenance of certain ecological functions all together. The key parameter of EHRA is to fix the watercourse cross-sectional flow area corresponding to EHR, by which the relation between parabola shaped cross-sectional flow area and hydraulic radius is deduced. The EHRA not only meets the requirement of flow velocity for adequate fish spawning migration, but also is applicable to the ecological flows in regard with other ecological issues (such as the calculation of the instream flow requirements for transporting sediment and for pollution self-purification, etc.). This essay has illuminated the computational process taking the estimation of ecological water requirement of Zhuba Hydrologyical Station watercourse in Niqu branch of the Yalong River as an example. Additionally, we compare EHRA with Tennant approach. The result shows that the Zhuba Hydrological Station ecological water requirement calculated by EHRA lies between the minimum and favorable ecological water requirement calculated by the Tennant approach. This is due to the fact that the ecological flow velocity (such as the fish spawning migration flow velocity) was taken into consideration, producing results applicable to the practical situation.

关键词： ecological flow flow velocity cross-sectional flow area ecological hydraulic radius (HER) instreamecological water requirement.

Experiments and sensitivity analyses for heat transfer in a meter-scale regularly fractured granite model with water flow

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Journal of Zhejiang university-Science A(Applied Physics & engineering) 2012年第12期13卷 958-968页

作者： Wei LU1,2.Yan-yong XIANG1 (1School of Civil engineering,Beijing Jiaotong university,Beijing 100044,{2.) (2.3} key laboratory of Simulation and Regulation of water Cycle in River Basin,{2. Institute of water resources and hydropower Research,Beijing 100038,{2.) 1. School of Civil engineering Beijing Jiaotong University Beijing 100044 China 2. state key {2. of Simulation and Regulation of water Cycle in River Basin China Institute of Water Resources and Hydropower Research Beijing 100038 China

Experiments of saturated water flow and heat transfer were conducted for a meter-scale model of regularly fractured granite. The fractured rock model （height 1502.5 ram, width 904 mm, and thickness 300 mm）, embedded with two vertical and two horizontal fractures of pre-set apertures, was constructed using 18 pieces of intact granite. The granite was taken from a site currently being investigated for a high-level nuclear waste repository in china. The experiments involved different heat source temperatures and vertical water fluxes in the embedded fractures either open or filled with sand. A finite difference scheme and computer code for calculation of water flow and heat transfer in regularly fractured rocks was developed, verified against both the experimental data and calculations from the TOUGH2.code, and employed for parametric sensitivity analyses. The experiments revealed that, among other things, the temperature distribution was influenced by water flow in the fractures, especially the water flow in the vertical fracture adjacent to the heat source, and that the heat conduction between the neighboring rock blocks in the model with sand-filled fractures was enhanced by the sand, with larger range of influence of the heat source and longer time for approaching asymptotic steady-state than those of the model with open fractures. The temperatures from the experiments were in general slightly smaller than those from the numerical calculations, probably due to the fact that a certain amount of outward heat transfer at the model perimeter was unavoidable in the experiments. The parametric sensitivity analyses indicated that the tem- perature distribution was highly sensitive to water flow in the fractures, and the water temperature in the vertical fracture adjacent to the heat source was rather insensitive to water flow in other fractures.

关键词： Fractured granite water flow Heat transfer Physical modeling Numerical calculation Sensitivity analysis

Some Massively Parallel Algorithms from Nature

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wuhan university Journal of Natural {2. 2002年第1期7卷 37-46页

作者： Li Yan, Kang Li-shan, Chen Yu-ping, Liu Pu, Cao Hong-qing, Pan Zheng-jun The state key {2. of Software engineering, wuhan university, wuhan 430072. Hubei, china wuhan university The State Key Laboratory of Software Engineering Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

We introduced the work on parallel problem solvers from physics and biology being developed by the research team at the state key {2. of Software engineering, wuhan university. Results on parallel solvers include the following areas: Evolutionary algorithms based on imitating the evolution processes of nature for parallel problem solving, especially for parallel optimization and model-building; Asynchronous parallel algorithms based on domain decomposition which are inspired by physical analogies such as elastic relaxation process and annealing process, for scientific computations, especially for solving nonlinear mathematical physics problems. All these algorithms have the following common characteristics: inherent parallelism, self-adaptation and self-organization, because the basic ideas of these solvers are from imitating the natural evolutionary processes.

关键词： evolutionary computation parallel algorithm imitating nature domain decomposition knowledge discovery in databases

Analysis-enhanced virtual globe for digital earth

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中国科学：技术科学英文版 2010年第S1期53卷 61-67页

作者： YUE Peng,GONG JianYa,XIANG LongGang & CHEN Jing state key {2. of Information engineering in Surveying,Mapping and Remote Sensing (LIESMARS),wuhan university,wuhan 430079,china 1. state key {2. of Information engineering in Surveying Mapping and Remote Sensing (LIESMARS) Wuhan University Wuhan 430079 China

Virtual globe has been recognized as an appealing technology to support the digital *** provides an intuitive and appealing way to visualize geospatial information,and is being used frequently to bring the globe-scale geospatial information to our *** easy access to virtual globes such as Google Earth,Microsoft Virtual Earth,and NASA World Wind allows both the general public users and professionals to use them for educational and research *** virtual globes provide a number of functions for geospatial data visualization and annotation,the geospatial analysis functions available in the current virtual globes are *** paper addresses an approach to the establishment of an analysis-enhanced virtual *** approach is based on the integration of virtual globe and interoperable geoprocessing *** an analysis-enhanced virtual globe combines the visualization and communication power of virtual globes with the conventional powerful analysis functions of GIS,thus meeting the analysis demands in digital earth.

关键词： virtual globe digital earth geoprocessing service GIS GeoGlobe GeoPW

Fabrication and Characterization of Nano Silver Powder Prepared by Spray Pyrolysis

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Journal of wuhan university of Technology(Materials Science) 2009年第6期24卷 871-874页

作者：章桥新 School of Mechanical and Electronic engineering Wuhan University of Technology state key {2. of Advanced Technology for Materials Synthesis & Processing Wuhan University of Technology

Silver powder was fabricated by spray pyrolysis, using 2.-2.% AgNO3 solution, 336-500 mL/h flux of AgNO3 solution, 0.2.-0.32.MPa flux of carrier gas and in the 62.-82. ℃ temperature range. The effects of furnace set temperature, concentration of AgNO3 aqueous solution, flux of AgNO3 aqueous solution as well as carrier gas on the morphology and particle size distribution of silver powder, were investigated. The experimental results showed that with the high concentration of AgNO3 aqueous solution, the average grain size of silver decreased with the increasing of furnace set temperature. But the gain size distribution was not homogenous, the discontinuous grain growth occurred. With the low concentration of AgNO3 aqueous solution, the higher furnace set temperature made the nano sliver grains sintered together to grow. Nano silver powder about 100 nm was fabricated by spray pyrolysis, using 2.t% AgNO3 solutions, 336 mL/h flux of AgNO3 aqueous solution, 0.32.MPa flux of carrier gas at 72. ℃ furnace set temperature.

关键词： nano silver powder fabrication characterization spray pyrolysis

HYDRODYNAMIC CHARACTERISTICS OF CHINESE STURGEON SPAWNING GROUND IN YANGTZE RIVER

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Journal of Hydrodynamics 2008年第2期20卷 225-230页

作者： YANG Yu YAN Zhong--min CHANG Jian-bo Nanjing Hydraulic Research Institute Nanjing 210029 China state key {2. of Hydrology-water resources and Hydraulic engineering Nanjing 210029 China College of water Conservancy and hydropower {2. Hohai University Nanjing 210098 China Institute of Hydro-ecology Wuhan 430072 China

Since the construction of the Gezhouba Dam on the Yangtze River in 1981, it has been found that the Chinese Sturgeon, Acipensor sinensis, performs natural propagation annually in a narrow reach downstream close to the Gezhouba Dam site. This might allow one to better investigate the river hydrodynamic conditions of the Chinese Sturgeon spawning ground. In this article, spatial Kinetic Energy Gradient （KEG） and absolute value of vorticity were computed along the river sections from measured data. The relation between Spawn Density per Unit Area （SDUA） and vorticity strength and between SDUA and KEG were worked out. The Results showed that the vorticity and KEG were both effective parameters for describing the hydrodynamic characteristics of Chinese Sturgeon spawning ground. The Chinese Sturgeons prefer to spawn in the river sections where the value of vorticity strength is larger than 0.4 s^-1 and KEG is larger than 0.02. Jkg^-1m^-1.

关键词： hydrodynamic characteristics Chinese Sturgeon spawning ground vorticity kinetic energy gradient Spawn Densityper Unit Area (SDUA)

Node ordinal encoded genetic algorithm for the optimal allocation of water resources

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Progress in Natural Science:Materials International 2005年第5期15卷 448-452页

作者： YANG Xiaohua1*, YANG Zhifeng 1,2. SHEN Zhenyao1 and LI Jianqiang3(1. state key {2. of water Environment Simulation, School of Environment, Beijing Normal university, Beijing 100875, china 2. key {2. for water and Sediment sciences Ministry of Education, School of Environment, Beijing Normal university, Beijing 100875, china 3. water resources and hydropower Planning and Design General Institute, MWR, Beijing 100011, china) state key {2. of water Environment Simulation School of Environment Beijing Normal University Beijing 100875 China key laboratory for {2. and Sediment sciences Ministry of Education School of Environment Beijing Normal University Beijing 100875 China water resources and {2. Planning and Design General Institute MWR Beijing 100011 China

A new method, node ordinal encoded genetic algorithm (NOEGA), is proposed for solving water resources optimal allocation problems, in which the capacity of water resources is split into a number of smaller parts so that successive operations can be overlapped. Our objective is to maximize the whole benefit function. To overcome the “dimensionality and algorithm complexity curse” while searching for solutions and looking for an optimal solution, the operations of one-point crossover operator, gene exchange operator, gene random operator, gene shift operator and node ordinal strings are established. It is proved to be an effective optimal method in searching for global solutions. The NOEGA does not need a diversity of initial population, and it does not have the problem of immature convergence. The results of two cases show that using NOEGA to solve the optimal allocation model is very efficient and robust. In addition, the algorithm complexity of NOEGA is discussed.

关键词： water resources optimal allocation node ordinal code genetic algorithm.

A new approach toward object-based change detection

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Science china(Technological sciences) 2010年第S1期53卷 105-110页

作者： ZHANG Guo1,2.LI Yang1 & LI ZhiJiang3 1 state key {2. of Information engineering in Surveying,Mapping and Remote Sensing,wuhan university,wuhan 430079,china 2.Satellite of Surveying and Mapping Application center,state Bureau of Surveying and Mapping,Beijing 100830,china 3 School of Printing and Packaging,wuhan university,wuhan 430079,china wuhan Univ State Key Lab Informat Engn Surveying Mapping & R Wuhan 430079 Peoples R China state Bur Surveying & Mapping Satellite Surveying & Mapping Applicat Ctr Beijing 100830 Peoples R China wuhan Univ Sch Printing & Packaging Wuhan 430079 Peoples R China

Object-based change detection has been the hotspot in remote sensing image processing.A new approach toward object-based change detection is *** two different temporal images are unitedly segmented using the mean shift procedure to obtain corresponding *** change detection is implemented based on the integration of corresponding objects’ intensity and texture *** are conducted on both panchromatic images and multispectral images and the results show that the integrated measure is robust with respect to illumination changes and *** color detection is conducted to determine whether the color of the unchanged objects changes or not when dealing with multispectral *** verification work is carried out to show the accuracy of the proposed approach.

关键词： mean shift united segmentation change detection object-based intensity texture integration

Dependence Analysis Based on Dynamic Slicing for Debugging

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wuhan university Journal of Natural {2. 2001年第Z1期6卷 398-404页

作者： Chen Zhen qiang 1, Xu Bao wen 1,2.1 Department of Computer Science & engineering, Southeast university, Nanjing 2.0096, {2. 2.state key laboratory of Software engineering, wuhan university, wuhan 430072. china Department of Computer Science & engineering Southeast University Nanjing 210096 China

Dynamic program slicing is an effective technique for narrowing the errors to the relevant parts of a program when debugging. Given a slicing criterion, the dynamic slice contains only those statements that actually affect the variables in the slicing criterion. This paper proposes a dynamic slicing method based on static dependence analysis. It uses the program dependence graph and other static information to reduce the information needed to be traced during program execution. Thus, the efficiency is dramatically improved while the precision is not depressed. The slicing criterion is modified to fit for debugging. It consists of file name and the line number at which the statement is.

关键词： program slice slicing criterion program dependence graph