检索结果-南通市图书馆

Thermal Conductivity and Heat Transfer Coefficient of Concrete

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan university of Technology(Materials Science) 2011年第4期26卷 791-796页

作者：郭利霞 North China university of water{2. and Electric Power

A very simple model for predicting thermal conductivity based on its definiensis was presented. The thermal conductivity obtained using the model provided a good coincidence to the investigations performed by other authors. The heat transfer coefficient was determined by inverse analysis using the temperature measurements. From experimental results, it is noted that heat transfer coefficient increases with the increase of wind velocity and relative humidity, a prediction equation on heat transfer coefficient about wind velocity and relative humidity is given.

关键词： thermal conductivity heat transfer coefficient relative humidity wind velocity

CHANGES OF PAN EVAPORATION IN THE UPPER REACH OF THE YANGTZE RIVER

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2011年第4期23卷 503-509页

作者： RONG Yan-shu WANG Wen JIANG Hai-yan College of hydrology and water{2. Hohai University Nanjing 210098 China State Key Laboratory of hydrology-water{2. and Hydraulic Engineering Hohai University Nanjing 210098 China

The upper reach of the Yangtze River, 4 511 km long from west to east, contains a great amount of water resources of the Yangtze River Basin. This article studies the characteristics of the pan evaporation, the related meteorological variables, and their effects on the pan evaporation, based on the data of the daily pan evaporation （1980-2.08） and other meteorological variables （1961-2.08）. The results show that the linear trend of the pan evaporation has remarkable regional features, i.e., the decrease trend in the southwest and the increase trend in the northeast of the investigated region, and the Yangtze River is approximately the boundary of these trends. The meteorological variables have different effects on the pan evaporation depending on the fact that they are in the category the thermal variables or the dynamic variables. The thermal meteorological variables （i.e., air temperature, diurnal temperature range, and sunshine duration） have positive partial correlations with the pan evaporation, while the dynamic ones （air pressure, rainfall, and relateive humidity） have negative correlations with the pan evaporation. The correlation of the wind speed remains to be investigated.

关键词： linear time trend meteorological variable pan evaporation partial correlation Yangtze River

Hybrid method of limit equilibrium and finite element internal force for analysis of arch dam stability against sliding

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2011年第4期54卷 793-798页

作者： BAO TengFei1,2.3,XU BaoSong1,2.3 & ZHENG XueQing1,2.3 1State Key Laboratory of hydrology-water{2. and Hydraulic Engineering,hohai university,nanjing 2.0098,China 2.ational Engineering Research Center of water{2. Efficient Utilization and Engineering Safety,nanjing 2.0098,China 3College of water Conservancy and Hydropower Engineering,hohai university,nanjing 2.0098,China 1. State Key Laboratory of hydrology-water{2. and Hydraulic Engineering Hohai University Nanjing 210098 China2. National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Nanjing 210098 China3. College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China

A hybrid method of limit equilibrium and finite element internal force for analysis of arch dam stability against sliding is *** finite element internal force method(FEIFM) is used to provide more accurate thrust forces acting on the faces of a slip body,and the limit equilibrium method(LEM) is employed to evaluate the factor of safety of the slip *** method presented can deal with a slip body with large amount of geometrically complex slip *** addition,compared with the traditional LEM,it can meet the balance condition of the forces in the slip *** example shows that the factor of safety obtained by the method presented agrees well with the theoretical solution.A practical example is also presented to demonstrate the application of the method in the stability analysis of an arch dam *** results from the examples show that the method is promising in analysis of arch dam stability against sliding.

关键词： arch dam stability against sliding limit equilibrium method finite element internal force method

Back analysis of mechanical parameters of roller compacted concrete dam

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2010年第3期53卷 848-853页

作者： GU ChongShi 1,2.3,LI Bo 1,XU GuangLei 4 &YU Hong 1,2.3 1 State Key Laboratory of hydrology-water{2. and Hydraulic Engineering,hohai university,nanjing 2.0098,China 2.ollege of water Conservancy Hydropower,hohai university,nanjing 2.0098,China 3National Engineering Research Center of water{2. Engineering Safety,Efficient Utilization and nanjing 2.0098,China 4 nanjing Hydraulic Research Institute,nanjing 2.002.,China 1. State Key Laboratory of hydrology-water{2. and Hydraulic Engineering Hohai University Nanjing 210098 China2. College of Water Conservancy Hydropower Hohai University Nanjing 210098 China3. National Engineering Research Center of Water Resources Engineering Safety Efficient Utilization and Nanjing Nanjing 210098 China4. Nanjing Hydraulic Research Institute Nanjing 210029 China

In view of the diversity and complexity of mechanical parameters of roller compacted concrete dam(RCCD),the uniform design method,partial least-squares regression(PLS)and least squares support vector machine(LSSVM)were applied to the back analysis of RCCD with the use of the complex nonlinear relationship between dam mechanical parameters and dam *** the process of back analysis,the initial samples of parameters were designed with uniform design ***,a transversely isotropic model of RCCD was established by *** *** this model,training samples of LSSVM model could be *** then,the complex nonlinear relationship between relative values of hydraulic components of dam displacements and mechanical parameters was ***,actual relative values of dam hydraulic components are isolated from the measured data of dam displacements by using *** inputting the isolated relative values into LSSVM model,the back analysis values of RCCD mechanical parameters can be *** example analysis showed that mechanical parameters obtained by the above-mentioned back analysis method are reasonable,and the back analysis method is feasible.

关键词： roller compacted concrete dam mechanical parameters back analysis

Multivariate analysis in dam monitoring data with PCA

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2010年第4期53卷 1088-1097页

作者： YU Hong1,2.WU ZhongRu1,2.BAO TengFei1,2.& ZHANG Lan1,2.1 State Key Laboratory of hydrology-water{2. and Hydraulic Engineering,hohai university,nanjing 2.0098,China 2.National Engineering Research Center of water{2. Efficient Utilization and Engineering Safety,hohai university,nanjing 2.0098,China 1. State Key Laboratory of hydrology-water{2. and Hydraulic Engineering Hohai University Nanjing 210098 China2. National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Hohai University Nanjing 210098 China

Given the limitation of traditional univariate analysis method in processing the multicollinearity of dam monitoring data,this paper reconstructs the multivariate response variables by introducing principal component analysis(PCA) method,explores the ways of determining principal components(PCs),and extracts a few PCs that have major influence on data *** steady observation series,a control field for the whole observation values has been established based upon PCA;for unsteady observation series that have significant tendency,a control field for the future observation values has been constructed according to PC statistical predication *** methods have already been applied to an actual project and the results showed that data interpretation method with PCA can not only realize data reduction,lower data redundancy,and reduce noise and false alarm rate,but also be effective to data analysis,having a broad application prospect.

关键词： dam safety monitoring multivariate response variables principal component analysis data reduction

Total control-based unified allocation model for allowable basin water withdrawal and sewage discharge

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2010年第5期53卷 1387-1397页

作者： HU SiYi1,2.WANG ZongZhi1,WANG YinTang1 & ZHANG LingLing3 1 State Key Laboratory of hydrology-water{2. and Hydraulic Engineering,nanjing Hydraulic Research Institute,nanjing 2.002.,China 2.Ministry of water{2.,the People’s Republic of China,Beijing 100053,China 3 school of Public Administration,hohai university,nanjing 2.0098,China 1. State Key Laboratory of hydrology-water{2. and Hydraulic Engineering Nanjing Hydraulic Research Institute Nanjing 210029 China2. Ministry of Water Resources the People’s Republic of China Beijing 100053 China3. School of Public Administration HoHai University Nanjing 210098 China

In this paper,a new model with a total amount control target of allowable water withdrawal based on initial water right is built for the implementation of initial water right allocation scheme as well as unified allocation for allowable water withdrawal and sewage *** model couples the water allocation simulation model and the computational model of permissible pol-lution bearing *** view of the model complexity,a new technology which synthesizes system simulation,iterative reservoir turns and intelligent computation is proposed to improve the operability of allocation scheme and computational *** the Beijiang River Basin in the Pearl River Basin as an example,the study explains the model establishment,solution and application,and draws an optimized operation graph of large-scale *** study also obtains a long-term operation strategy of river basin water resources system,the allocation schemes of allowable water withdrawal and sewage discharge in a typical year and the flow hydrographs of trans-boundary *** validity of the model and the allocation rationality are analyzed as well.

关键词： water resources management total control unified control of water withdrawal and sewage discharge optimized regulation integration technology

Damage and progressive failure of concrete structures using non-local peridynamic modeling

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2011年第3期54卷 591-596页

作者： HUANG Dan1,2. ZHANG Qing1,2.& QIAO PiZhong1,3 1 State Key Laboratory of hydrology-water{2. and Hydraulic Engineering, hohai university, nanjing 2.0098, China 2.Department of Engineering Mechanics, hohai university, nanjing 2.0098, China 3 Department of Civil and Environmental Engineering, Washington State university, Pullman, WA 99164-2.10, USA 1. State Key Laboratory of hydrology-water{2. and Hydraulic Engineering Hohai University Nanjing 210098 China2. Department of Engineering Mechanics Hohai University Nanjing 210098 China3. Department of Civil and Environmental Engineering Washington State University Pullman WA 99164-2910 USA

Peridynamics (PD), a recently developed theory of solid mechanics, which employs a non-local model of force interaction and makes use of integral formulation rather than the spatial partial differential equations used in the classical continuum mechanics theory, has shown effectiveness and promise in solving discontinuous problems at both macro and micro scales. In this paper, the peridynamics theory is used to analyze damage and progressive failure of concrete structures. A non-local peridynamic model for a rectangular concrete plate is developed, and a central pairwise force function is introduced to describe the interior interactions between particles within some definite distance. Damage initiation, evolution and crack propagation in the concrete model subject to in-plane uni-axial tension, in-plane uni-axial compression and out-of-plane impact load are investigated respectively. The numerical results show that discontinuities appear and grow spontaneously as part of the solution to the peridynamic equations of motion, and no special failure criteria or re-meshing techniques are required, which proves the potential of peridynamic modeling as a promising technique for analyzing the progressive failure of concrete materials and structures.

关键词： concrete damage progressive failure peridynamic model discontinuities

Field experiments on greenhouse gas emissions and nitrogen and phosphorus losses from rice paddy with efficient irrigation and drainage management

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2011年第6期54卷 1581-1587页

作者： PENG ShiZhang1,2.YANG ShiHong1,2.XU JunZeng1,2.& GAO HuanZhi1,2.1State Key Laboratory of hydrology-water{2. and Hydraulic Engineering,hohai university,nanjing 2.0098,China 2.ollege of water Conservancy and Hydropower Engineering,hohai university,nanjing 2.0098,China 1. State Key Laboratory of hydrology-water{2. and Hydraulic Engineering Hohai University Nanjing 210098 China2. College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China

Greenhouse gas emissions,nitrogen and phosphorous losses through ammonia volatilization,leaching and surface drainage from rice paddy under efficient irrigation and drainage were analyzed based on field experimental data in order to reveal the eco-environmental impacts of efficient irrigation and drainage on rice *** results showed that total methane emission from rice paddy under the controlled irrigation was reduced by more than 80% and total nitrous oxide emission increased by 15.9% compared with flooding *** comprehensive global warming potentials(GWP) of methane and nitrous oxide were 62.2. gCO2.m-2.for rice paddy under the controlled irrigation,reduced by 68.0% compared with flooding *** to large reduction in seepage and surface drainages,nitrogen and phosphorous losses through leaching were reduced by 40.1% and 54.8%,nitrogen and phosphorous losses through surface drainage were reduced by 53.9% and 51.6% from rice paddy under efficient irrigation and drainage compared with traditional irrigation and *** loss through ammonia volatilization was reduced by 14.0%.Efficient irrigation and drainage management is helpful to mitigate greenhouse gases emission,nitrogen and phosphorus losses and their pollution on groundwater and surface water.

关键词： efficient irrigation and drainage nitrogen and phosphorus greenhouse gas ammonia volatilization paddy field

Isotope Method for Confined Groundwater Recharge of the Lower Reaches of the Heihe River,Inner Mongolia,China

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2007年第4期81卷 668-673页

作者： CHEN Jiansheng ZHAO Xia FAN Zhechao and WANG Jiyang 1 State Key Laboratory of hydrology-water{2. and Hydraulic Engineering,hohai university,nanjing 2.0098,China 2.Institute of Isotope hydrology Research,hohai university,nanjing 2.0098,China 3 Institute of Geology and Geophysics,Chinese Academy of Science,Beijing 100018,China State Key Laboratory of hydrology-water{2. and Hydraulic Engineering Hohai University Nanjing 210098 China

Environmental isotopes have been appfied to analyze confined groundwater recharge in the lower reaches of the Heihe River, Inner Mongolia. CFC is regarded as a tracer that determines the date of groundwater, the date being less than 45 a. The confined groundwater within the Gurinai area and Ejin Basin other than the surface water of Heihe River might have originated from precipitation from Qilian Mountain or/and the Tibetan Plateau. The deep confined groundwater overflows into an upper aquifer and emerges into the ground, forming springs and lakes within the low-lying area. The recharge volume is estimated to be around 400 million-cubic meters.

关键词： isotope CFC Ejin Basin Gurinai groundwater recharge precipitation Qilian Mountain