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Enthalpies of Solution of Complexes of Rare Earth Nitrate with L-α-Histidine in Water
The enthalpies of solution in water of complexes of RE(NO3)3 (RE=La～Nd, Sm～Lu, Y) with L-α-Histidine (His) were measured at 298.15 K. The standard enthalpies of formation of RE(His)3+(aq) were calculated. The "tetrad effect" regularity was observed from the curve, which is the enthalpies of solution plotted against the atomic numbers of the elements in lanthanide series....
2020-07-08 21:52:19浏览：58
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Unstructured finite volume method for water impact on a rigid body
A new method is presented for the water impact simulation, in which the air-water two phase flow is solved using the pressure-based computational fluid dynamics method. Theoretically, the air effects can be taken into account in the water structure interaction. The key point of this method is the air-water interface capture, which is treated as a physical discontinuity and can be captured by a well-designed high order scheme. According to a normalized variable diagram, a high order discrete scheme on unstructured grids is realised, so a numerical method for the free surface flow on a fixed grid can be established. This method is implemented using an in-house code, the General Transport Equation Analyzer, which is an unstructured grid finite volume solver. The method is verified with the wedge water and structure interaction problem....
2020-07-08 21:52:19浏览：60
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Test of numerical prediction of sea water temperature in the Taiwan Strait
A dynamic numerical prediction model of sea water temperature for limited sea area is used to predict the sea water temperature at the sea area near Fujian. Essential adjustments have been made in accordance with the characteristics of this region. Two tests have been made. One is in summer (3 d) and the other is in winter (10 d). In the summer test, a typhoon is just passing by and the calculated current field well responds to typhoon. In the winter test, variation tendency of the predicted sea water temperature field agrees with that of the observation basically, the absolute mean error in the whole sea area is 0.6 ℃. The variation of the sea water temperature is mostly affected by entrainment and pumping, which is related to the topography of the strait....
2020-07-08 21:52:19浏览：54
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Application of SEDEA to evaluation of degree of harmony between water resources and economic develop
This paper introduces the method of data envelopment analysis (DEA) for evaluation of the degree of harmony between water resources and economic development of the water conservancy area of China's South-to-North Water Diversion Project (SNWDP). For this evaluation, a super-efficiency DEA (SEDEA) model was developed based on the super-efficiency method. To verify the applicability of the SEDEA model, both the SEDEA model and a normal-efficiency DEA (NEDEA) model were used to evaluate the degree of harmony between water resources and economic development of typical cities in the SNWDP water conservancy area. The results show that the SEDEA model ranks the degree of harmony of typical cities more efficiently than the NEDEA model, and thus can better evaluate the degree of harmony between water resources and economic development of different cities than the NEDEA model.Furthermore, the SEDEA model can be applied as an operational research tool in regional water resources management....
2020-07-08 21:52:19浏览：58
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Mechanism analysis of landslide of a layered slope induced by drawdown of water level
The frequent drawdown of water level of Yangtze River will greatly influence the stability of the widely existing slopes in the Three Gorges reservoir zone, especially those layered ones. Apart from the fluctuating speed of water level, the different geological materials will also play important roles in the failure of slopes. Thus, it must be first to study the mechanism of such a landslide caused by drawdown of water level.A new experimental setup is designed to study the performance of a layered slope under the drawdown of water level. The pattern of landslide of a layered slope induced by drawdown of water level has been explored by means of simulating experiments. The influence of fluctuating speed of water level on the stability of the layered slope is probed,especially the whole process of deformation and development of landslide of the slope versus time. The experimental results show that the slope is stable during the water level rising, and the sliding body occurs in the upper layer of the slope under a certain drawdown speed of water level. In the process of slope failure, some new small sliding body will develop on the main sliding body, and the result is that they speed up the disassembly of the whole slope.Based on the simulating experiment on landslide of a layered slope induced by drawdown of water level, the stress and displacement field of the slope are calculated.The seepage velocity, the pore water pressure, and the gradient of pore water head are also calculated for the whole process of drawdown of water level. The computing results are in good agreement with the experimental results. Accordingly, the mechanism of deformation and landslide of the layered slope induced by drawdown of water level is analyzed. It may provide basis for treating this kind of layered slopes in practical engineering....
2020-07-08 21:52:19浏览：63
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Removal of cyclops in pre-oxidizing cooperation water treatment process
Zooplankton cyclops propagates profusely in waterbody, cannot be effectively inactivated by conventional disinfection process, and becomes a troublesome drinking water treatment problem. In this work, the qualitative and quantitative experimental studies were carried out on inactivation of zooplankton cyclops using oxidants, such as chlorine (Cl2), chlorine dioxide (ClO2), ozone (O3), hydrogen peroxide (H2O2), ozone/hydrogen peroxide (O3/H2O2), chloramines (Cl2-NH3) and potassium permanganate (KMnO4). The influences of various factors include different oxidant dosages, organic substance contents and pH values. The results showed that currently available oxidants used all might inactivate cyclops in some extent. According to the experimental results, chlorine dioxide, ozone, ozone/hydrogen peroxide and chloramines can be selected as effective oxidants for inactivating cyclops because of their strong inactivation abilities. Then the synergic removal effects on cyclops with ozone,ozone/hydrogen peroxide pre-oxidation followed by conventional water treatment processes were investigated. The results showed that ozone and ozone/hydrogen peroxide pre-oxidation can inactivate cyclops effectively, which then can be removed thoroughly by conventional water treatment processes. Cyclops cannot appear in water after filtration with 1.65 mg/L of ozone and 6 mg/L of hydrogen peroxide, with the inactivation rate being 62% before conventional water treatment processes. Cyclops cannot appear in water after filtration with 1.8 mg/L of ozone, with the inactivation rate being 50% before conventional water treatment processes. For different oxidants, when removal rate was the best, the inactivation rate was not the same. These results may provide reference and model for actual waterworks....
2020-07-08 08:49:41浏览：39
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Relative roles of resuspended particles and pore water in release of contaminants from sediment
Sediment layers containing contaminants play a significant role in environmental hydrodynamics. Experiments were conducted in order to characterize the relative roles of resuspended particles and pore water under different flow and sediment conditions. A conservative tracer (NaCl) and a reactive tracer (phosphate) were used as contaminants in the bottom sediment in a laboratory flume. The mixing between the overlying water and pore water occurred over a short time while the desorption of contaminants from fine-grained resuspended particles lasted a relatively long time. The effects of resuspended particles and pore water on the variations of release flux and concentration of contaminants in water with time under different hydrodynamic conditions were quantified. The results show that pore water dominated the initial release flux, which could be several orders of magnitude greater than the flux due to molecular diffusion. Flux contribution of desorption from sediment particles in the latter release could be equal to what was seen from pore water in the initial stage....
2020-07-08 08:49:41浏览：51
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The Influence of Water Level Change in Slope Stability of Earth Dam
The analysis of seepage flow and slope stability to earth dam in water level change is performed. FEM is used to analyzing the influence of percolation and the results including the pore water head of any point, seepage discharge and so on are obtained. The method of slices is introduced to calculating the slope stability of the earth dam. Through an example it is separately discussed the influence of seepage flow when water level is changed in earth dam slope and the effects of percolation in the stability of the earth dam slope. Some helpful conclusions are gained.This can be making the best of the tow methods and the results can be used in engineering for reference....
2020-07-08 08:49:41浏览：57
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Human activity response and prevention strategies on soil and water loss in Sichuan Province
Ten major factors have been selected to judge the degree of disturbance from human activity and the corresponding relationship of the impact on soil and water loss in Sichuan Province. Correlation analysis has demonstrated that stock-carrying capacity, percentage of land reclamation, population density, GDP per capita, mineral modulus and percentage of forest coverage are the 6 most relevant human activity factors. The analysis on the degree of disturbance has shown that population pressure, excessive or unreasonable activities in development of resources and destructive behavior of humans are the main causes of soil and water loss. Consequently, solving the various problems in the negative activity of humans and regulating human behavior are the first tasks that should be tackled in the conservation of water and soil. In the new era, the prevention and rectification of soil and water loss are measures based on the foundation of the ecosystem, which is a kind of management strategy for sustainable development. The foundation of this method is made up of the system innovations and breakthroughs in terms of aims, philosophy, measures, and aspects of the prevention and rectification of soil and water loss, simultaneous advance from the conceptual, policy, spatial, technical and mode levels and system integration on the treatment strategies....
2020-07-08 08:49:41浏览：50
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Exploration of Water Resource and Multiple Model for Water Resource Development in Karst Areas with
According to the theory of preferred plane, preferred planes (faults) always control the distribution of bedrock fissure water and hold abundant groundwater. Thus, the exploration of fissure or karst water can be converted into searching for the watery preferred plane (WPP). In the paper, the characteristic of watery preferred planes is analyzed and a series of superior indices has been set up. It is introduced that WPPs are determined by the methods of geological analysis, superior index and complex geophysical analysis. Meanwhile, new multiple model for water resource development in the water-scarce areas of karst mountainous regions are advanced....
2020-07-08 08:49:41浏览：51
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THE BALANCE BETWEEN SUPPLY AND DEMAND OF WATER RESOURCES AND THE WATER-SAVING POTENTIAL FOR AGRICULT
The Hexi Corridor is an important base of agriculture development in Northwest China. According to re-cent statistics, there are 65.94 × 108m3 of water resources available in the Hexi Corridor. At present, net consumption indevelopment and utilization is 43.33 x 108m3. Water supply and demand reach a balance on the recent level of produc-tion, but loss of evaporation and evapotranspiration is as much as 25.69 × 108m3. So net use efficiency of water resourcesis 59%. Based on analyzing balance between water and land considering ecological environment at present, there existsthe serious water shortage in the Shiyang River system where irrigation lands have overloaded. There is a comparative bal-ance between supply and demand of water resource in the Heihe River system; and the Sule River system has some sur-plus water to extend irrigation land. Use of agriculture water accounts for 83.3% and ecological forest and grass for6. 9%. The Hexi Corridor still has a great potential for water saving in agriculture production. Water-saving efficiency ofirrigation is about 10% by using such traditional technologies as furrow and border-dike irrigation and small check irriga-tion, and water-saving with plastic film cover and techniques of advanced sprinkler and drip/micro irrigation etc. cansave more than 60% of irrigated water. Incremental irrigation area for water-saving potential in the Hexi Corridor hasbeen estimated as 56% - 197% to original irrigation area. So the second water sources can be developed from water sav-ing agriculture in the Hexi Corridor under Development of the Western Part of China in large scale. This potential can berealized step by step through developing the water-saving measures, improving the ecological condition of oasis agricul-ture, and optimizing allocation of water resources in three river systems....
2020-07-08 08:49:41浏览：64
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ABRUPT DEFLECTED SUPERCRITICAL WATER FLOW IN SLOPED CHANNELS
The effect of the bottom slope on abrupt deflected supercritical water flow was experimentally and theoretically studied. Model tests were conducted in a flume of 1.2 m wide and 2.6 m long with sloped bottom at an angle 35.54o, its length of deflector was 0.2 m and the deflection angles were 15o and 30o. An approximate method for calculatjng the shock wave angle and depth ratio of the abrupt deflected supercritical water flow was suggested, and a correction coefficient for the hydrodynamic pressure was introduced to generalize the momentum equation in the direction perpendicular to the shock front. It must be noticed that in the sloped channel the shock wave angle and the depth ratio are no longer constant as those in the horizontal channels, but slowly change along the shock front. The calculated results are in good agreement with measured data....
2020-07-08 08:49:41浏览：65
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Plastic mechanism of deformation of garnet-- Water weakening
The strongly deformed eclogites are well developed in ultra-high pressure jadeite-quartzite zone of the Dabie Mountains, Eastern China, and garnets had been deformed strongly. Observations by transmission electron microscopy identified not only structure of plastic deformation occurring as free dislocation, dislocation loops and dislocation walls, but also clusters of water molecules present in the deformed garnet. Using infrared spectroscopy, two types of hydrous components are identified as the hydroxyl and free-water in the garnet. Based on analysis of microstructure mechanism of deformation in garnets, and experimental data of petrology, the clusters of water molecules were considered to lead strong plastic deformation of garnet by dislocations because of mechanical weakening....
2020-07-08 08:49:41浏览：44
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Evaluation on the Essentiality Grades of Water Conserving in Tibet, China
Taking Tibet as an example, the functional essentiality degrees of water resources conserving of regions were discussed in this paper. At first, based on the status of regional vegetation, whether the region has the function of water conserving was made certain. And then, according to the impacted objects of water resources conserving, taking into account the demands for water and regional supply capacities of water and the requirement of environmental protection, the functional grades of regional water resources conserving of Tibet were evaluated in this paper....
2020-07-08 08:49:41浏览：58
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Qingdao City Resources Water Price Estimate
The water resource price is currently one of the difficult problems of water price research.After references collection,investigation and analysis,the water resource price of Qingdao City was calculated by applying fuzzy mathematics.According to the present situation and region characteristic of Qingdao,water quality,per capita water supply,economical level,population density and ahemative water resources were selected as water resource influence factors and weigh coefficients of all these factors were ascertained.The results show that the water resource price of Qingdao is 3.05yuam/m3 and total water price is 4.65Yuan/m3....
2020-07-08 08:49:41浏览：39
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