移动通信网基站电磁辐射调研及居民环境超标原因分析

对北京市区近 2 0 0个移动电话基地站电磁辐射进行了测试 ,结合基地站电磁辐射特征对电磁辐射超标原因进行分析。从规划布局、天线架设规范方面提出了减小移动电话基地站电磁辐射污染的对策     

移动通信基站电磁辐射实例分析

随着移动通信技术的发展，基站的电磁辐射受到越来越多的关注。本文介绍了分析移动通信基站的电磁辐射情况预测模型，结合天线的方向性和增益情况对不同地区不同辐射方向上的电磁辐射情况做出预测并与实测数据进行比较分析。     

关于安全工程专业培养计划的思考

我国经济建设和精神文明正在协调发展 ,如何适应安全科学教育的新发展机遇是人们安全教育工作者所关注和深思的问题。笔者在分析新世纪安全人才需求特点的基础上 ,探讨了安全人才的知识结构与培养模式 ;指出安全工程专业人才 ,除应系统掌握安全科学的基本理论、基本方法以及安全生产的基本规律外 ,还要与采矿、冶金、建筑、机械、电气、化工、交通、环境等专业的必修专业基础课有机结合 ,在课程内容 ,教学结构方面 ,实现优化配置 ,提高学生综合分析和解决实际安全问题的能力。另外 ,在注意多层次培养安全技术人才的同时 ,还要加强对高校其他非安全工程专业大学生的安全知识教育 ,提高其安全文化素质 ,在今后的工作和活动中能自觉充分地考虑安全问题。     

基于标准模型库的企业财务风险分析方法探析

笔者在对企业财务风险指标进行科学选取的基础上 ,利用主成分分析法和因子分析方法计算企业财务风险综合得分 ;依照所得的两种综合得分进行风险聚类 ;并以聚类结果构建企业财务风险标准模型库。该风险标准模型库形成了企业财务风险的相对静态数据参考 ,据此 ,监管部门可方便地运用模糊识别方法对企业财务数据进行风险判断和分类 ,不需对加大样本的企业数据进行重新计算 ,大大提高了工作效率。该方法综合了几种方法的优点 ,在实践中得到了较合理的分析结果。     

地基-基础隔震系统整体地震响应有限元分析

近几十年来,基础隔震技术逐渐被重视,得到了广泛的应用,并被纳入国家建筑抗震设计规范。但是在传统的理论分析中,对于基础隔震结构往往忽视土-结构动力相互作用对其隔震效果的影响。即使考虑地基的影响,也大都是采用弹簧和阻尼器(地基动刚度)代替。笔者运用ANSYS软件的二次开发功能,提出将结构、隔震层和地基结合起来作为一个完整系统分析,并对一叠层橡胶基础隔震7层钢筋混凝土框架结构在考虑土-结相互作用情况下,进行了整体地震响应有限元计算、比较、分析。结果表明进行地基-基础隔震系统整体地震响应有限元分析是完全可行的而且是必要的。     

ESTIMATION OF STREAMFLOW,BASE FLOW,AND NITRATE‐NITROGEN LOADS IN IOWA USING MULTIPLE LINEAR REGRESSION MODELS1

Nineteen variables, including precipitation, soils and geology, land use, and basin morphologic characteristics, were evaluated to develop Iowa regression models to predict total streamflow (Q), base flow (Qb), storm flow (Qs) and base flow percentage (%Qb) in gauged and ungauged watersheds in the state. Discharge records from a set of 33 watersheds across the state for the 1980 to 2000 period were separated into Qb and Qs. Multiple linear regression found that 75.5 percent of long term average Q was explained by rainfall, sand content, and row crop percentage variables, whereas 88.5 percent of Qb was explained by these three variables plus permeability and floodplain area variables. Qs was explained by average rainfall and %Qb was a function of row crop percentage, permeability, and basin slope variables. Regional regression models developed for long term average Q and Qb were adapted to annual rainfall and showed good correlation between measured and predicted values. Combining the regression model for Q with an estimate of mean annual nitrate concentration, a map of potential nitrate loads in the state was produced. Results from this study have important implications for understanding geomorphic and land use controls on streamflow and base flow in Iowa watersheds and similar agriculture dominated watersheds in the glaciated Midwest.     

真实感图形技术在润扬大桥北锚基坑建基面稳定性分析中的应用

锚锭基础抗滑稳定性是桥梁设计所要考虑的一个重要方面,而基坑建基面的起伏状况又直接影响着锚锭建基面基岩与混凝土胶结面的抗剪强度参数。因此,本文针对润扬大桥北锚基坑建基面起伏状况的分析,在DTM(digital terrain model)的基础上,选择MapInfo作为GIS的开发平台,利用真实感图形技术实现了北锚基坑建基面的三维可视化效果,并利用MapInfo强大的测量分析和信息统计功能对北锚基坑建基面的起伏状况进行了详细的分析,分析结果直接以图形形式显示,能够较为客观的反映整个基坑建基面的综合情况,便于政府决策部门和设计施工单位相关人员间的相互交流,为工程设计服务。     

开发和建设西南能源基地的战略意义

开发和建设西南能源基地在我国能源工业发展和布局中占有重要的地位。西南地区的煤炭集中分布在川、滇、黔接壤地区,保有储量占全国的 8.9％,位居第二。而水能蕴藏量2.9亿多kW,占全国的42％,可开发利用量1.9亿多kW,占全国的51％,年发电量1.03万亿度,占全国的54％,加上西藏,水能蕴藏年发电量约占全国的70％。煤炭工业在全国已有较大发展,已初步建成以山西为中心的煤炭基地,六盘水煤炭基地,两淮煤炭基地等等。石油天然气工业发展较快,核电工业正在起步和发展。但是水能资源的开发利用和蕴藏量相比,还很不相称。全国水能资源利用率只有4-5％,西南地区按发电量计算,仅占水电可开发总量的1.3％。因此,在当前我国能源供应十分紧张的情况下,开发西南能源基地的水能资源和煤炭资源,有着十分重大的战略意义。     

粤东中生代火山旋回划分及对比

本文在基本查明火山岩系地层层序及变化的基础上,将粤东地区中生代火山岩划分为上、下两个岩系,四个旋回,对各旋回特征作了简要总结,并进行了区域对比分析。     

A decision inventory approach for improving decision support for climate change impact assessment and adaptation

Assessing and adapting to the impacts of climate change requires balancing social, economic, and environmental factors in the context of an ever-expanding range of objectives, uncertainties, and management options. The term decision support describes a diverse class of resources designed to help manage this complexity and assist decision makers in understanding impacts and evaluating management options. Most climate-related decision support resources implicitly assume that decision making is primarily limited by the quantity and quality of available information. However, a wide variety of evidence suggests that institutional, political, and communication processes are also integral to organizational decision making. Decision support resources designed to address these processes are underrepresented in existing tools. These persistent biases in the design and delivery of decision support may undermine efforts to move decision support from research to practice. The development of new approaches to decision support that consider a wider range of relevant issues is limited by the lack of information about the characteristics, context, and alternatives associated with climate-related decisions. We propose a new approach called a decision assessment and decision inventory that will provide systematic information describing the relevant attributes of climate-related decisions. This information can be used to improve the design of decision support resources, as well as to prioritize research and development investments. Application of this approach will help provide more effective decision support based on a balanced foundation of analytical tools, environmental data, and relevant information about decisions and decision makers.