火灾科学中计算机模拟的新进展

本文主要讨论了火灾计算机模拟的三种新的数值模型，即场区模型、场区网模型及综合模型；并运用此三种模型分别对三种情形下发生的火灾进行了计算机模拟，结果表明此三种模型是可行的。     

临街建筑群中交通噪声的计算机模拟

给出了临街建筑群中纵深方向的交通噪声计算机模拟预测方法。交通干道上车流采用泊松分布和等车距车流相结合模型，考虑多种车型的不同声功率级。每辆车作为一个点声源，以几何声学方法考虑直达声和有限次反射声对测点的影响。在计算程序中只要输入车流量，车流成份，建筑群中有关巷道宽度，测点在巷子纵深方向距离及背景噪声等数据，计算机便能输出Ｌ１０，Ｌ５０，Ｌ９８，Ｌｅｑ等声级值。模拟结果和实测值基本一致。     

基于卫星雷达数据的鄱阳湖湿地水面检测与淹露分析

以鄱阳湖自然保护区湿地为例,对多时相、多极化的合成孔径雷达(ENVISAT ASAR)数据作主成分分析,得到主成分分量影像,其中次要分量波段包含大部分的局部变异信息,使用主成分分量波段和log算子提取了ASAR影像中湿地淹没变化信息.结果表明,鄱阳湖自然保护区湿地对外湖水位变化有滞后效应,但总体上,其淹没变化仍显著地受到鄱阳湖外湖洪水的影响.与分类后检测法、分类前变化探测法等方法相比,所采用的变化检测方法可得到更为理想的ASAR影像湿地淹没变化信息提取的精度.使用同极化/交叉极化组合模式的ASAR数据对水面变化检测的精度明显优于同极化波段(HH/VV)组合的数据.     

支撑环境监测预警体系的计算机信息系统建设思路

环境监测预警体系只有依靠计算机信息系统才能发挥其作用,根据预警体系的特点、内容以及要实现的功能,论述了信息系统硬件建设和软件建设的基本要求、系统的组成和系统实现的方法。     

Development of inherent safety and health index for formulated product design

The numerous formulated products which are introduced to the market consist of chemical ingredients that may cause various safety and health hazards to the consumers. Therefore, it is extremely important to practice a systematic methodology to formulate products with acceptable safety and health performances. This work presents an index-based methodology to assess the safety and health hazards of the ingredients during the early formulation stage of product design. Hence, new inherent safety and health sub-indexes are introduced to improve the current safety and health hazards that are needed in formulated product design. The inherent safety and health sub-indexes are assigned with scores based on the degree of potential hazards. A higher score indicates a higher safety risk or severe health effect, and vice versa. The proposed methodology will greatly assist the users to identify the adverse safety and health effects caused by the ingredients. Hence, it is pivotal to eliminate or reduce the safety and health impacts from product usage. A case study on common ingredients used in the formulation of paint is presented on this study to describe the proposed method.     

Multiple-resource modeling as a tool for conservation: Its applicability in Mexico

The current Mexican environmental law provides the legal basis for comprehensive land-use planning. Under the law, development of natural ecosystems must combine goals, policies, and practices towards the sustainable use of natural resources and the protection of biological diversity. Thus, ecosystem manipulation must be able to counter fragmentation of natural ecosystems and isolation of natural reserves, while providing for human needs. Assessment of the potential of natural ecosystems and management impacts are required. Multiple-resource simulation is an assessment and land-use planning tool that permits managers and decision makers to comply with the law, providing a flexible, user-oriented system that can meet the needs of managers, conservationists, and researchers. A multiple-resource model and an example of how it can be applied to meet planning needs is presented for discussion.     

计算机绘制大气污染物浓度分布等值线图

用计算机绘制大气污染物长期平均浓度分布等值线图，对在绘图过程中坐标系的建立，计算机间距的确定以及风向的加密等的处理方法作了讨论，并给出了绘图的基本步骤。     

计算机辅助法兰类锻件计算

此文分析了常见几种法兰锻件图特点,给出了法兰锻件图上各圆角圆心坐标及圆弧和相邻线段的切点坐标及法兰锻件体积计算公式,并进—步采用计算机辅助计算锻件体积,提高了计算精度并大大减轻了手工计算的繁重劳动。     

用计算机模拟送进角与辗轧角对Accu-Roll轧机变形区的影响

在建立Accu-Roll轧机变形区模型的基础上,开发出计算机模拟软件,可方便地通过变形区纵剖面计算机图象显示分析工艺参数对变形区的影响,从而为合理地选取与优化工艺参数提供依据。     

计算机杂草识别技术的研究现状

针对不同的杂草种类分别采取光谱分析法，颜色分析法，纹理分析法以及外形分析法来识别的特点，介绍了国外在该领域的研究应用进展，提出了计算机杂草识别技术的意义及在我国的发展前景。