军民协调灾害卫生救援体制的情报与模式研究

通过对国内外军民协调灾害卫生救援体制现状的对比分析，找出我国现行灾害卫生救援体制与国外体制之间的差距，分析了产生差距的原因．在此基础上，从加强军民协调、平战结合角度，提出我国灾害卫生救援体制四种框架模式，运用专家咨询法与层次分析法相结合的方法进行综合评估。明确了我国军民协调灾害卫生救援体制发展的战略目标和近中期目标，从而提出加强我国军民协调灾害卫生救援体制建设的对策与建议．     

GENERATION OF HOURLY RAINFALL1

ABSTRACT: A rainfall model was developed to divide daily rainfall into storms and distribute storm depths over storm duration for input into the Stanford Watershed Model.     

浅谈秦皇岛市旅游开发问题

旅游开发导向模式由旅游资源和客源市场确定。对于旅游开发而言,导向模式的确定是关键,本文对秦皇岛市的旅游开发现状进行了分析,由此确定了导向模式,同时对旅游开发与保护的关系进行了探讨。     

General concepts for measuring cumulative impacts on wetland ecosystems

Because environmental impacts accumulate over space and time, analysis is difficult, and we must incorporate the most recent scientifically defensible information and methods into the process. Methods designed to deal specifically with cumulative impacts include checklists of characteristics or processes, matrices of interactions (rated according to their level of importance) between disturbance activities and environmental conditions, nodal networks or pathways that depict probable effects of disturbances, and dynamic system models. These methods have been tested over the past decade and have proven generally successful.Landscape perspectives have emerged as especially helpful in analyzing cumulative effects, and have focused specific attention on questions of spatial and temporal scale, while leading to recognition of the complexity of ecosystem processes in general. An evaluation of several cases studies by the Commission on Life Sciences of the U.S. National Academy of Sciences emphasizes the importance of interactions and cumulative effects, but recognizes that current knowledge of the processes involved is insufficient to make specific recommendations for conceptual frameworks.The conceptual approach suggested by Preston and Bedford (1988) addresses many critical issues, such as the need to define dimensions of scale, and the importance of wetland size, shape, and location in the landscape. This approach and similar ones must be tested and evaluated so that a consensus may eventually emerge.A cumulative impact matrix is proposed that sets up additive, synergistic, and indirect categories, each capable of variation in space and time. Every interaction would be carefully examined to determine the likelihood of cumulative impact in any of the six categories. Because of its magnifying glass approach, such a matrix could be a very useful analytical tool, using existing methods to uncover all the information presently available about the behavior of the ecosystem of concern.     

基于DHGF算法的水资源定价模型研究

通过将DHGF算法与水资源价格上限理论相结合,构建了基于DHGF算法的水资源定价模型,并对模型工作步骤进行了设计。最后以西安市水资源为例,对该模型进行实例检验。结果表明该模型具有可行性和实际应用价值。     

城市下水道污水水质模型的开发与应用

建立了下水道水质转化概念模型,以ASM3(活性污泥3号模型)为基础开发了下水道污水水质数学模型,通过模拟试验,运用遗传算法和曲线拟合技术进行了模型率定与参数估值.模型经现场试验验证可较好地模拟下水道中的ρ(DO)与ρ(TOC)的变化.应用该模型进行数值模拟,探讨了初始ρ(DO)和水力停留时间(HRT)等可控因素对下水道中微生物作用及有机质降解的影响.结果表明,在下水道中设置曝气点,可提高污水的ρ(DO),能有效地提高微生物增殖速率,强化有机物的生化降解能力.      

Dispersion modeling of LNG-Vapor on land – A CFD-Model evaluation study

Based on methane from renewable resources, LNG is an alternative fuel for heavy and long-distance traffic in land transport. Contrary to its positive properties, the fuel contains risks from an explosion and extremely low temperatures for personal and infrastructure safety. CFD-models are suitable for doing risk analyses for arbitrary scenarios. For examining how to model for risk research the dispersion of LNG-vapor, this paper contains a model variant study, with an evaluation by experiments.This paper describes the use of the CFD-code ANSYS Fluent for simulating experiments of the ‘LNG Safety Program Phase II‘. The content of the well-documented experiments was the research of the vaporization rate of LNG on land and the dispersion of LNG-vapor in the air. Based on the comparison to two experiments, overall 12 CFD-model variants with varying thermal and turbulence parameters were examined how they affect the transient LNG-vapor dispersion in air.The definition of turbulence-boundary-condition at the domain borders had the biggest impact on modeling, followed by the turbulence model. The most accurate model variant had been applied for observing the spreading behavior of LNG-vapor in the air after evaporation on land and analyzing the influence of the LNG-composition to the dispersion. The results show that the mixture of LNG-vapor and the air in the free field is cooler than the ambient air and spreads like a heavy gas on the ground.     

Two-dimensional modeling of torrefaction of a large biomass particle

A two-dimensional (2-D) model is developed to predict the torrefaction behavior of a large wet biomass particle. Although one-dimensional (1-D) model is found to be adequate for L/D ≥ 6, the necessity of using 2-D model at lower L/D ratios and higher torrefaction temperature is established. Errors up to 18% are observed in predicted mass fractions between 1-D and 2-D models. The center temperatures differed more, up to 96%, between z = 0 and z = L/2 in 2-D model which is not captured by the 1-D model. The model predictions agree well with the experimental results of the present authors and others. The evolution of the temperature profile is found to govern the mass fraction profile. At higher reactor temperature, three distinct zones are visible in the contour plots: peripheral fully torrefied zone, intermediate torrefying zone, and core with unreacted virgin biomass zone. Simulation studies show the formation of two symmetric annular hot spots at the ends, which move inward axially and subsequently merge at the center, the rate being faster for smaller L/D ratio. However, 1-D model does not provide such insight. The effects of reactor temperature, particle size, the residence time, and the initial moisture content on the torrefaction behavior are investigated.     

A spatial-temporal system for dynamic cadastral management

A practical spatio-temporal database (STDB) technique for dynamic urban land management is presented. One of the STDB models, the expanded model of Base State with Amendments (BSA), is selected as the basis for developing the dynamic cadastral management technique. Two approaches, the Section Fast Indexing (SFI) and the Storage Factors of Variable Granularity (SFVG), are used to improve the efficiency of the BSA model. Both spatial graphic data and attribute data, through a succinct engine, are stored in standard relational database management systems (RDBMS) for the actual implementation of the BSA model. The spatio-temporal database is divided into three interdependent sub-databases: present DB, history DB and the procedures-tracing DB. The efficiency of database operation is improved by the database connection in the bottom layer of the Microsoft SQL Server. The spatio-temporal system can be provided at a low-cost while satisfying the basic needs of urban land management in China. The approaches presented in this paper may also be of significance to countries where land patterns change frequently or to agencies where financial resources are limited.     

黑河流域生物生产量分布趋势测算研究

黑河流域地处干旱地带,水资源紧缺,天然绿洲植被迅速退化,流域的生态环境状况十分严峻。本文应用迈阿密模型以及作者提出的修正方法,对黑河流域的生物生产量进行了测算及分布趋势分析,所得结果对黑河流域以及西北干旱地区的水土资源利用和生态环境保护具有应用价值