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Study on the double-logarithmic profile of tidal flow velocity in the near-bed layers

Acta Oceanologica Sinica 2009年第6期28卷 84-92页

作者： NI Zhihui SONG Zhiyao WU Lichun Southwestern Research Institute of water Transport Engineering Chongqing Jiaotong UniversityChongqing 400016 China Key Laboratory of Virtual Geographic Environment （Ministry of Education） Nanjing NormMUniversity Nanjing 210097 China State Key Laboratory of hydrology-water{2. and Hydraulic Engineering Hohai UniversityNanjing 210098 China Chongqing Education College Chongqing 400067 China

Tidal current velocity profile in the near-bed layers has been widely studied. The results showed that velocity profile in the near-bed layer obviously departure from the traditional logarithmic profile, due to the acceleration or deceleration. Although the logarithmic linear profile can reduce the rate of deviation from this, only it is a lower-order approximate solution. In this paper, considering the unsteady and non-linear features of tidal motion, the double logarithmic profile near-bed layers in estuarine and coastal waters is established on the assumption that the turbulent shear stress along the water depth was parabolic distribution, and on the basis of Prandtl＇s mixing length theory and yon Karman＇s self-similar theory. Having been verified the data observed at the West Solent in the south of England, and comparison of the logarithmic linear profile, it found that the double logarithmic profile is more precious than the latter. At last, the discussed results showed that：（1） The parabolic distribution of the tidal shear stresses verified good by the field data and experimental data, can be better reflected the basic features of the tidal shear stress deviating from linear distribution that is downward when to accelerate, upward when to decelerate. （2. The traditional logarithmic velocity profile is the zero-order approximation solution of the double logarithmic profile, the logarithmic linear profile is the first order, and the logarithmic parabolic profile is the second order. （3） Ignoring the conditions of diffusion and convection in the tida movement, the double logarithmic profile can reflect the tidal properties of acceleration or deceleration, so that the calculation of the friction velocity and roughness length are more reasonable. When the acceleration or the deceleration is about zero, the double logarithmic profile becomes the logarithmic profile.

关键词： turbulence shear stress tidal current double logarithmic profile near-bed layers friction velocity roughness length

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A NEW IMPLICIT SCHEME FOR SOLVING 3-D SHALLOW water FLOWS

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Journal of Hydrodynamics 2009年第6期21卷 790-798页

作者： ZHANG Zhuo SONG Zhi-yao LV Guo-nian State Key Laboratory of hydrology water{2. and Hydraulic Engineering Ocean College Hohai University Nanjing 210098 China Key Laboratory of Virtual Geographic Environment Ministry of Education Nanjing Normal University Nanjing 210097 China

Based on the improved ADI method, this article proposes an improved implicit finite difference scheme for solving 3-D shallow water flows. The main objective is to design a numerical relation between the horizontal velocity on each layer and the depth-averaged velocity for employing the improved ADI method. With the free surface elevation and the depth-averaged velocity obtained by using essentially 2.D depth-averaged mode, the velocity profiles can be obtained easily and simultaneously. The wind-induced flows, the open channel flows due to the pressure gradient and the tidal flows in coastal waters are simulated, and the results are consistent well with the analytical solution and the field data, which shows that the present implicit scheme is stable and effective, and the established model is practical. Moreover, when only one vertical layer is specified, the present 3-D numerical model is reducea to the 2.D depth-averaged model.

关键词： shallow water equation ADI method wind-induced flow gravity-drived flow tidal flow

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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 Laboratory of hydrology-water{2. and Hydraulic Engineering Nanjing 210029 China College of water Conservancy and Hydropower Engineering 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)

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EXPERIMENTS OF THREE-DIMENSIONAL FLOW STRUCTURE IN BRAIDED RIVERS

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Journal of Hydrodynamics 2009年第2期21卷 228-237页

作者： HUA Zu-lin GU Li CHU Ke-jian Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education College of Environmental Science and Engineering Hohai University Nanjing 210098 China State Key Laboratory of hydrology-water{2. and Hydraulic Engineering Hohai University Nanjing210098 China

The braided river is a typical river pattern in nature, but there is a paucity of comprehensive data set describing the three-dimensional flow field in the braided river. A physical model experiment was used to study the flow characteristics in the typical braided river with a mid-bar between two anabranches. In the experiment, two kinds of mid-bar with the ratios of its length to maximal width of 3 and 5 were considered. Moreover, the mid-bar could be moved to adjust the width of two anabranches. The detailed measurements of velocity were conducted using an acoustic Doppler velocimeter over a grid defined throughout the whole braided river region, including the bifurcation, two anabranches and the confluence. In two kinds of mid-bar braided models, a separation zone was observed in the anabranch of the model in which the ratio of length to maximal width of mid-bar is 3, however the separation zone was not found in another model in which the ratio is 5. In addition, the opposite secondary cells were observed at the bend apex of anabranch in two models, and different longitudinal velocity distributions in the entrance region of anabranch account for this opposite flow structure. Finally, turbulent kinetic energy were shown and compared in different situations. The high turbulence occurs at the place with strong shear, especially at the boundary of the separation zone and the high velocity passing flow.

关键词： braided river three-dimensional flow structure secondary flow turbulent kinetic energy

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Migration of Infiltrated NH_4 and NO_3 in a Soil and Groundwater System Simulated by a Soil Tank

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Pedosphere 2008年第5期18卷 628-637页

作者： WANG Chao WANG Pei-Fang State Key Laboratory of hydrology- water{2. and Hydraulic Engineering Key Laboratory of Integrated Regulationand Resource Department on Shallow Lakes Ministry of Education Environmental Science and Engineering CollegeHohai University Nanjing 210098 （China）.

The infiltration of water contaminants into soil and groundwater systems can greatly affect the quality of groundwater. A laboratory-designed large soil tank with periodic and continuous infiltration models, respectively, was used to simulate the migration of the contaminants NH4 and NO3 in a soil and groundwater system, including unsaturated and saturated zones. The unsaturated soil zone had a significant effect on removing NH4 and NO3 infiltrated from the surface water. The patterns of breakthrough curves of NH4 and NO3 in the unsaturated zone were related to the infiltration time. A short infiltration time resulted in a single sharp peak in the breakthrough curve, while a long infiltration time led to a plateau curve. When NH4 and NO3 migrated from the unsaturated zone to the saturated zone, an interracial retardation was formed, resulting in an increased contaminant concentration on the interface. Under the influence of horizontal groundwater movement, the infiltrated contaminants formed a contamination-prone area downstream. As the contaminants migrated downstream, their concentrations were significantly reduced. Under the same infiltration concentration, the concentration of NO3 was greater than that of NH4 at every corresponding cross-section in the soil and groundwater tank, suggesting that the removal efficiency of NH4 was greater than that of NO3 in the soil and groundwater system.

关键词： breakthrough curve migration NH4 NO3 soil tank experiment

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Research on Methods of Ecological Security Assessment of the Middle and Lower Reaches of Liaohe River Based on GIS

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Chinese Journal of Population,resources and Environment 2005年第4期3卷 20-25页

作者： Wang Geng 1,2., Nie Baochi 3, Wang Lin 1 & Wu Wei 1 1. school of Environmental and Biological Science and Technology, Dalian university of Technology, Dalian 11602., China 2. Urban and Environmental school, Liaoning Normal university, Dalian 11602., China 3. Shenyang Buraue of water resources, Shenyang 110013, China. school of Environmental and Biological Science and Technology Oalian University of Technology Oalian 116024 China Urban and Environmental school Uaoning Nonnal University Oalian 116029 China Shenyang Buraue of water resources Shenyang 110013 China

Ecological security assessment and early warning research possess the attributes of spatiality, non-linearity and randomicity, so we must process much spatial information. Spatial analysis and data management are the advantages of GIS, which can define distribution trend and spatial relations of environmental factors, and show ecological security pattern graphically. Spatial differences of ecological security assessment based on GIS are discussed in this paper, of which the middle and lower reaches of the Liaohe River is taken as a study case. First, to work out pressure-state-response (P-S-R) assessment indicators system, and investigate in person and gather information; second, to digitize the watershed; third, to quantize and calculate by the fuzzy method; last, to construct GIS grid database, and expound spatial differences of ecological security by GIS interpolation and assembly analysis.

关键词： the middle and lower reaches of the Liaohe River ecological security assessment indicators system GIS spatial differences

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梯级水电站实时补偿增益多因素综合分配方法探讨

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水力发电学报 2008年第6期27卷 22-26页

作者：钟平安曹静蔡杰河海大学水文水资源学院南京210098

龙头水库带一串日调节或无调节电站组成的水电梯级,在汛初和汛期两场洪水之间的特定时段开展小流量泄流补偿调度,既可以减少龙头水库无益弃水,又能增加下游电站发电量;分析了影响实时补偿调度增益分配的主要因素;提出了补偿调度增益的... 详细信息

龙头水库带一串日调节或无调节电站组成的水电梯级,在汛初和汛期两场洪水之间的特定时段开展小流量泄流补偿调度,既可以减少龙头水库无益弃水,又能增加下游电站发电量;分析了影响实时补偿调度增益分配的主要因素;提出了补偿调度增益的计算原理和龙头水库泄流补偿调度风险率与期望损失计算方法;提出了具有明确物理意义的补偿调度增益多因素综合分配模型。通过沙溪流域的实例分析,表明提出的方法能够取得合理的结果。

关键词：水利经济增益分配梯级水电站实时补偿调度

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Comparison of heavy metal accumulation by a bloom-forming cyanobacterium,Microcystis aeruginosa

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Science Bulletin 2012年第Z2期 3790-3797页

作者： ZENG Jin 1*,ZHAO DaYong 2.JI YongBan 1 & WU QingLong 1 1 State Key Laboratory of Lake Science and Environment,nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,nanjing 2.0008,China 2.State Key Laboratory of{2.-water resources and Hydraulic Engineering,College of{2. and water resources,hohai university,nanjing 2.0098,China

Microcystis aeruginosa is the dominant species during cyanobacterial blooms in freshwater *** the present study,we compared the bioaccumulation characteristics of cadmium(Cd) and zinc(Zn) in Microcystis *** short-term uptake tests,a rapid sorption of Cd and Zn occurred in the first few minutes,with a subsequent slower internalization *** obvious difference was observed between Zn and Cd in terms of their short-term uptake *** efflux experiments,elimination of Zn from the cells was faster than that of *** the 72.h exposure tests,the intracellular Cd concentrations increased with exposure time whereas the intracellular Zn concentrations always reached a *** cellular Cd showed greater variation than the cellular Zn at various free Cd 2. or Zn 2. *** differences in Cd and Zn accumulation and elimination indicated that Microcystis cells had a higher bioaccumulation capacity for Cd than for *** field studies,the bioconcentration factor(BCF) of Cd in lake-harvested Microcystis was more than 10 times higher than those of other *** results of the present study strongly suggested that the bloom-forming Microcystis may affect the Cd transportation and biogeochemical cycling in eutrophic freshwater ecosystems.

关键词： Microcystis aeruginosa cadmium zinc bioaccumulation bioconcentration factor

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Geothermal and fluid flowing simulation of ore-forming antimony deposits in Xikuangshan

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Science China Earth Sciences 2006年第8期49卷 862-871页

作者： YANG Ruiyan1,2. MA Dongsheng2. BAO Zhengyu3, PAN Jiayong2. CAO Shuanglin2.& XIA Fei2.1. school of Mathematics and Physics, China university of Geosciences, Wuhan 430074, China 2. State Key Laboratory for Research of Mineral Deposits,{2. university,{2. 2.0093, China 3. Faculty of Earth Sciences, China university of Geosciences, Wuhan 430074, China 1. school of Mathematics and Physics China University of Geosciences Wuhan 430074 China 2. State Key Laboratory for Research of Mineral Deposits Nanjing University Nanjing 210093 China 3. Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China

The Xikuangshan Antimony Deposit located in the Mid-Hunan Basin, China, is the larg- est antimony deposit in the world. Based on the hydrogeological and geochemical data collected from four sections, Xikuangshan-Dajienao (AO), Xikuangshan-Dashengshan (BO), Xikuang- shan-Longshan (CO) and Dafengshan (DO) in the Basin, an advanced metallogenic model related to deep-cyclic meteoric water of Xikuangshan Antimony Deposit is put forward in this paper using a model of heat-gravity-driving fluid flow transportation. The simulation results show that the ore-forming fluid of the deposit mainly comes from the Dashengshan and Longshan areas where BO and CO sections are located if the overall basin keeps a constant atmospheric precipitation and infiltration rate during mineralization, and that the average transportation speed of the ore-forming fluids is about 0.2.0.4 m/a.

关键词： ore-forming fluid, numerical simulation, geothermal field, geofluid transport, Xikuangshan, antimony deposits.

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Synthesis and Lubrication of Phosphorylcholine Derivative

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Journal of Bionic Engineering 2010年第3期7卷 254-258页

作者： Zhenliang Qiao~1, Dangsheng Xiong~1, Lude Lu~2. Pengju Jiang~2.1. Department of Materials Science and Engineering, nanjing university of Science and Technology, nanjing 2.0094, P.R. China 2. school of Chemical Engineering, nanjing university of Science and Technology, nanjing 2.0094, P. R. China [a] Department of Materials Science Engineering Nanjing University of Science Technology Nanjing 210094 P.R. China [b] School of Chemical Engineering Nanjing University of Science Technology Nanjing 210094 P. R. China

The monomer of phosphorylcholine derivative, O-(5-（2.methacryloxy）-3, 3-dimethyl-3-azapentyl)-O’-（ω-hydroxy-octyl）-phosphatequaternary ammonium salt, was designed and synthesized successfully. It was characterized by the spectra ofHNMR and Mass spectra （ESI+）, and every signal was assigned. Then the lubricating characteristics of the phosphorylcholinederivative were investigated on the tribological setup of ball-oh-flat. The Ultra-High Molecular Weight Polyethylene（UHMWPE） flat was rotated against a stainless steel ball with 6 mm diameter. The load was 2.3 N, which corresponded to amaximal Hertz contact pressure of 2. MPa. water, phosphorylcholine derivative, and Acrylic Acid （AA） solution were used aslubricants, respectively. Compared with AA, the phosphorylcholine derivative shows significant lubrication. It can be stronglyhydrated under water due to the charged segment in chemical structure. The thick water layers within the chains serves asboundary lubricants, and this is thought to be the molecular origins of lubricating behavior.

关键词： artificial joint articular cartilage molecular lubrication mechanism phosphorylcholine synthesis UHMWPE

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