基于网格的洪水损失计算模型

首先系统总结了基于GIS和遥感的洪水灾害损失评估框架,并重点阐述了洪水淹没范围的提取和水深的计算;在此基础上,针对洪水灾害损失中的3种主要承灾体(农作物、线状设施以及人员伤亡),提出了基于空间网格的洪水损失计算模型,模型以空间网格为计算单元,以淹没损失曲线为基础;最后,将此模型应用到沱江流域的洪灾损失评估中,得到了较好的结果.

中国煤矿安全事故损失计算模型研究

分析了煤矿安全事故处理过程中可能发生的各项经济损失,根据它们的特征和性质将其划分为直接价值因素损失、间接价值因素损失和非价值性因素损失3大类。引入伤害分级比例系数法进行事故人员伤亡价值损失的估算,有利于对伤亡矿工赔付额的界定。建立了煤矿事故损失计算模型,同时给出了各项费用的计算公式,并将该模型应用于我国辽宁孙家湾"2.14"煤矿事故的损失计算,对计算结果进行了分析,并进行经济损失程度分级。结果显示,模型计算得到损失大小和损失组成特点符合实际。

水污染造成的水资源价值损失分析——以福州市第二水源山仔水库为例

该文讨论了水资源的价值及价格 ,在回顾已有的水污染经济损失计算模型的基础上 ,应用 L .D詹姆斯等模型 ,对山仔水库地区水污染趋势进行分析 ,并估算其污染造成的价值损失。

城镇地质环境经济评价研究

本文提出城镇地质环境经济评价新概念。较详细地讨论了该评价的基本思想，主要环境地质因素，指标体系与常用的损失计算模型。最后用该评价的理论对三峡库区迁建城镇新址地质环境质量损益进行了概略性经济评价。

Coupling model for calculating prestress loss caused by relaxation loss,shrinkage,and creep of concrete

The calculation model for the relaxation loss of concrete mentioned in the Code for Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts(JTG D62—2004) was modified according to experimental data. Time-varying relaxation loss was considered in the new model. Moreover, prestressed reinforcement with varying lengths(caused by the shrinkage and creep of concrete) might influence the final values and the time-varying function of the forecast relaxation loss. Hence, the effects of concrete shrinkage and creep were considered when calculating prestress loss, which reflected the coupling relation between these effects and relaxation loss in concrete. Hence, the forecast relaxation loss of prestressed reinforcement under the effects of different initial stress levels at any time point can be calculated using the modified model. To simplify the calculation, the integral expression of the model can be changed into an algebraic equation. The accuracy of the result is related to the division of the periods within the ending time of deriving the final value of the relaxation loss of prestressed reinforcement. When the time division is reasonable, result accuracy is high. The modified model works excellently according to the comparison of the test results. The calculation result of the modified model mainly reflects the prestress loss values of prestressed reinforcement at each time point, which confirms that adopting the finding in practical applications is reasonable.

Application of fuzzy theory on earthquake damage rate estimation of buildings

Variations between earthquakes result in many factors that influence post-earthquake building damage(e.g.,ground motion parameters,building structure,site information,and quality of construction).Consequently,it is necessary to develop an appropriate building damage-rate estimation model.The building damage survey data were recorded and constructed into files by the Architecture and Building Research Institute(ABRI),Taiwan for the 1999 Chi-Chi earthquake in the Nantou region as a basis for developing a building damage rate estimation model by applying fuzzy theory to express the fragility curves of buildings as a membership function.Empirical verification was performed using post-earthquake building damage data in the Taichung city that suffered relatively severe damage.Results indicate that fuzzy theory can be applied to predict building damage rates and that the estimated results are similar to actual disaster figures.Prediction of disaster damage using building damage rates can provide a reference for immediate disaster response during earthquakes and for regular disaster prevention and rescue planning.

The Efficiency Improving of Traction Drive Test Bench with Supercapacitor Energy Storage System

For development of passenger electrical transport, it is necessary to use energy more rationally. One of methods of vehicle power efficiency increase is installation of on-board energy storage systems. For studying of system operation, it is necessary to carry out a lot of experiments, therefore it is favorable to use the test bench and its computer model for reduction of the number of physical experiments. In this article, the results of computer modeling for the optimization of traction drive test bench by adjusting of the operation parameters of supercapacitor energy storage are described. Test bench operation is considered in cases of the energy storage system working at various selected supercapacitor initial voltages. Maximal increase of possibility of vehicle test bench regenerative braking with minimal decrease of autonomous power supply mode possibility is investigated. There is estimated the energy storage system efficiency improving measures dependence from supercapacitor operational voltage ranges. Parameters at which the minimum losses of energy are observed are revealed. Dependence of energy storage system discharge power on the most admissible supercapacitor current is established.

Empirical Model for the Quantitative Prediction of Losses of Radial Fans based on CFD Calculations

In a classical layout process of a fan the quantity of losses is estimated as a sum and expressed in the overall efficiency rote However the characteristic of the pressure rise, the losses and the efficiency rate beside the design point is not known. Against this background a numerical model was developed to calculate quantitative values of occurring losses at radial fan impellers at an early stage in the design process. It allows to estimate the pressure rise and efficiency rate of a given fan geometry at and beside the design point. The physics of losses are described in literature, but obtaining quantitative values is still a challenge. As common in hydraulic theory the losses are calculated with analytic formulas supported by coefficients and efficiency rates, which have to be determined empirically. This paper shows the method how to determine the coefficients for a given radial fan. Therefore a representative radial fan with backward curved blades was designed in reference to classical design guidelines. Performance measuring was done conform to ISO 5801. The flow was calculated at 8 different operation points using CFD methods. The RANS equations are solved by using the SST-k-omega turbulence model. The flow do- main consists of one blade section including inlet channel and outflow chamber. Spatial discretization is done by a block-structured mesh of approx. 1.8 million cells. Performance data show a very good agreement between measurement and calculation.