Particle size dependent response of aerosol counters

During an international workshop at the Institute for Experimental Physics of the University of Vienna, Austria, which was coordinated within the Committee on Nucleation and Atmospheric Aerosols (IAMAS-IUGG), 10 instruments for aerosol number concentration measurement were studied, covering a wide range of methods based on various different measuring principles. In order to investigate the detection limits of the instruments considered with respect to particle size, simultaneous number concentration measurements were performed for monodispersed aerosols with particle sizes ranging from 1.5 to 50 nm diameter and various compositions.The instruments considered show quite different response characteristics, apparently related to the different vapors used in the various counters to enlarge the particles to an optically detectable size. A strong dependence of the 50% cutoff diameter on the particle composition in correlation with the type of vapor used in the specific instrument was found. An enhanced detection efficiency for ultrafine hygroscopic sodium chloride aerosols was observed with water operated systems, an analogous trend was found for n-butanol operated systems with nonhygroscopic silver and tungsten oxide particles.     

资源勘查图件计算机辅助编绘系统的结构分析与开发策略研究

如何站在信息系统的高度来进行资源图件计算机辅助编绘系统的快速开发，是资源信息系统领域计算机应用的一个重要研究课题。在结构分析的基础上，将资源图件计算机辅助编绘系统划分为图形数据库，应用图形系统和基础图形系统3个基本部分。对于复杂资源图件的计算机辅助编绘，需要地矿点源信息系统的支持。在基础图形系统上进行专业编绘程序的二次开发是高效建立图件编绘系统的最佳途径，并需注意GIS集成应用，三维可视化，人工智能和参数化设计等方法的运用，而系统平台开发是复杂应用的高级阶段。该思想可应用于煤及油气勘探，工程开发，矿区管理及区域地质等诸多领域的软件开发中。     

三峡库区滑坡治理工程设计中推力荷载计算方法初探

随着三峡水利工程的逐步实施，淹没区移民及新城镇建设等人类工程活动的加剧，以滑坡为主的环境地质问题日益突出。本文从稳定系数、安全系数入手，对铁道、公路等部门常用的设计计算原理进行了研究，并由此类比分析研究了三峡区回水后或库水位正常运行条件下，滑坡治理工程设计计算方法。     

Optimal design of passive energy dissipation systems based on H∞ and H2 performances

Passive energy dissipation devices (EDDs), such as viscous dampers, viscoelastic dampers, etc., have been used to effectively reduce the dynamic response of civil infrastructures, such as buildings and bridges, subject to earthquakes and strong winds. The design of these passive energy dissipation devices (EDDs) involves the determination of the optimal locations and the corresponding capacities. In this paper, we present two optimal design methodologies for passive EDDs based on active control theories, including H_∞ and H₂ performances, respectively. The optimal design methodologies presented are capable of determining the optimal locations and the corresponding capacities of EDDs. Emphasis is placed on the application of linear matrix inequality (LMI) for the effective design of passive EDDs using the popular MATLAB toolboxes. One important advantage of the proposed approaches is that the computation of the structural response is not needed in the design process. The proposed optimal design methodologies have been applied to: (i) a 10‐storey building and a 24‐storey building both subject to earthquake excitations, and (ii) a 76‐storey wind‐excited benchmark building, to demonstrate the advantages of the proposed design methodologies over the conventional equal capacity design. Copyright © 2002 John Wiley & Sons, Ltd.     

Towards a direct collapse–load method of design for concrete frames subjected to severe ground motions

Most current methods of design for concrete structures under earthquake loads rely on highly idealized ‘equivalent’ static representations of the seismic loads and linear‐elastic methods of structural analysis. With the continuing development of non‐linear methods of dynamic analysis for the overload behaviour and collapse of complete concrete structures, a more direct and more accurate design procedure becomes possible which considers conditions at system collapse. This paper describes an evaluation procedure that uses non‐linear dynamic collapse–load analysis together with global safety coefficients. A back‐calibration procedure for evaluating the global safety coefficients is also described. The aim of this paper is to open up discussion of alternative methods of design with improved accuracy which are necessary to move towards a direct collapse–load method of design. Copyright © 2002 John Wiley & Sons, Ltd.     

DEM在公路设计中的应用

根据公路部门的实际工作,利用数字高程模型这一新的数字地理信息产品,采用空间分析的一些方法,应用AMI语言,对公路设计和施工中断面图的绘制、挖、填方量的计算等一些实际问题进行探讨和实践,并在此基础上构建了<宣芜高速公路设计应用示范系统>.     

粉喷桩技术加固软土地基

简介了水泥粉体喷射搅拌加固软土地基的工作机理,结合沪蓉高速公路(沪宁段)地基处理实践,论述了粉喷桩加固软土地基的计算方法.采用粉喷桩加固软基,可加快路堤填土速率,铺筑路面后的工后沉降量能得到有效地控制,保证了工程质量.     

马岭油田北三区污水回注的实验研究

根据马岭油田北三区油田水性质，结合污水与地层水混合的静态实验结果分析，发现污水回注对地层可能引起不同程度的伤害。同时，模拟地层条件做岩心流动实验。将采出的污水回注到地层与地层水混合后，亦会使地层渗透率下降，且随着污水含量的增加，渗透率伤害程度增大。     

用翁氏模型图版设计早期油气田(藏)开发方案

由于缺乏早期资料，设计早期油气田（藏）开发方案是非常困难的。在制作翁氏模型的Qctm/No-ER图版和ER-ctR图版过程提出根据探明储量No、经济极限产量Qc、假定达到峰值产量的时间tm、最终采收率ER，由翁氏模型的Qctm/No-ER图版求取增长指数b，由翁氏模型ER-ctR图版求取ctR，再求出其他参数及所有的油气田（藏）开发指标，完成早期油气田（藏）开发方案设计。     

A multi-scale study on land use and land cover quality change: The case of the Yellow River Delta in China

This paper presents a case study of the Yellow River Delta in China, to trace land use and land cover changes during the past 20 years, with an emphasis on land quality changes. Three sets of data are used in this case study: remote sensing data derived from satellite images; crop yield data from statistics; and soil data collected by the researchers in the field. Our study reveals that at the regional scale, LUCC has taken place in a positive direction: vegetation cover has been expanding and crop yields per hectare have been on rise. However, while the overall eco-environment has improved, the improvement is uneven across the Delta region. At local levels, some areas show signs of increased salinization and declining organic content. Both natural forces and human activities are responsible for the LUCC, but human activities play a more important role. While some impacts of human activities are positive, the damages are often long-lasting and irreversible. We also conclude that it is necessary to use both macro data (such as remote sensing data) and micro data (data collected in the field) to study land quality change. The former are efficient in examining land quality changes at the regional scale, the latter can serve to verify ground patterns revealed from macro data and help to identify local variations, so as to get a comprehensive understanding of LUCC and promote sustainable land use and land management. This revised version was published online in July 2006 with corrections to the Cover Date.