多氯代二苯并呋喃QSRR的拓扑量子方法研究

由于分子邻接矩阵能很好地表征分子的结构,以多氯代二苯并呋喃中不同的分子碎片实测的第一电离能为主元,构建分子的拓扑邻接矩阵,解得其特征根,参照分子轨道(MO)的概念。指定其中2个特征根为分子轨道的前线轨道HOMO,运用多元线性回归法,将矩阵特征根HOMO和分子体积作为参数,对多氯代二苯并呋喃在三种不同固定相中的色谱保留指数(RI)和相对保留时间(RRT)作相关分析,其相关系数都在0．968以上。所得方程的良好相关性,说明该方法合理、有效。     

消除反射波干扰的新方法及其性能分析

利用三元传感器阵消除反射波干扰的新方法,分析了抵消反射干扰的性能;推导了消除反射干扰后提取直达信号的表达式;分析了反射干扰截断误差、随机噪声和直达信号与反射干扰相关程度对恢复直达信号性能的影响;给出了在实际应用中提高抵消反射干扰性能的几点措施。通过计算机仿真的方法给出了该方法的统计性能。理论分析及仿真结果表明：只要知道信号的波达方向,就可以从基阵的接收信号中有效地消除反射波的干扰。该方法的优点是可以消除未知传播方向的反射干扰。     

建筑抗震设计规范GB50011-2010问题解答(一)

国家工程建设标准《建筑抗震设计规范GB50011-2010》于2010年12月1日实施以来,各地工程技术人员在按新规范进行建筑抗震设计时,产生和遇到了各种各样的问题,并通过各种渠道将问题反映到规范管理组.为及时回答这些问题,补充完善,甚至是修正规范的某些不妥之处,为此,《工程抗震与加固改造》从2012年2期开始,开辟“建筑抗震设计规范问题解答”专栏连载有关文章,将有关问题整理归类、逐条回答.本文针对规范第1～3章所提出的问题加以解答,供读者参考和批评指正.     

高校新校区建筑缺陷修缮问题研究

高校新建建筑物在使用一段时间后,暴露出了设计或者建造中的缺陷.与此同时,建筑物会受到各种不利环境的影响,有害物质的侵蚀,人为的损坏作用以及自然灾害的作用,导致建筑物使用质量下降.通过对新校区建筑物缺陷进行实地调查和数据分析研究,对如何确定修缮方案和修缮费用进行探讨,并提出了自己的看法.     

Seismic damage analysis of reinforced concrete buildings based on statistics of structural lateral resistance

The largest revision of the building code in Japan was released in 1981, in which the examination of ultimate lateral strength of structure is required. As a result, the capacity of the earthquake resistance of buildings is different between those designed before and after the revision of the code.The objective of this paper is to evaluate the seismic reliability of two groups of reinforced concrete buildings; one is the building group designed by the current code (after the 1981 revision) and the other is the building group designed by the former code (before the revision). The site is assumed to be Sendai city, Japan. Seismic reliability analyses of buildings are carried out and the probability of structural responses exceeding certain response levels during 100 years is evaluated for each type of building group. In addition to the uncertainty of earthquake forces, the uncertainties of structural characteristics, such as lateral resistance and the first natural period of structures, are considered based on the statistics of existing buildings.     

高层筏基大体积混凝土施工和裂缝控制工程实践

在南京国际贸易中心大厦大体积混凝土施工中，裙楼和塔楼底板混凝土分别采用全面分层浇筑和一次成型浇筑的工艺、温度监控及施工技术和施工组织等方面的质量控制措施；并对２种施工方案、混凝土施工过程中的测试数据进行了比较分析。     

高层建筑桩筏基础设计中几个问题

本文针对上海软土高层建筑桩筏基础常规设计中的一些问题，例如筏板基础埋深，试桩容许承载力的取值，桩持力层的选取，裙房和高层建筑整体设计等提出作者的看法以供设计者参考。     

单双管供暖系统水力计算中的手算方法

按“不等温降”计算法的思路对高层建筑单双管系统进行了变通处理，给出了水力计算中整根立管的折算阻力系数，以便进行单双管混合式系统的水力计算．     

Seismic response of multi-storey steel buildings with flexible connections

In the limit states design of steel building frames, usually simplifying assumptions are made with regard to the behaviour of beam-to-column connections. The Canadian standard for steel buildings recognizes three such sets of assumptions. One of them is the ‘special simple construction’ in which the beam-to-column connections are assumed to be completely free (pinned) to resist gravity loads and are assumed to be ‘rigid’ to resist the lateral loads due to earthquake or wind. Such connections are then designed for moments due to lateral loads only, and thus they are usually flexible. This paper is concerned with the influence of the connection flexibility and the strength on the overall strength and stiffness of steel building frames. The study considers 10 storey and 20 storey office buildings. The first part of the paper illustrates the analysis and design of the 10 storey building on the basis of ‘special simple construction’. By using realistic connection behaviour, the frames were subjected to equivalent static loads due to wind or earthquake and El Centro, 1940 earthquake excitation. In the nonlinear static analysis the building frames were subjected to specified gravity loads and incremental lateral loads until failure. In the nonlinear dynamic analysis the buildings were subjected to specified gravity loads and 70% of El Centro, 1940 earthquake excitation. For comparison purposes the frames were analysed twice, first assuming rigid connections and then with flexible connections. The static analyses results show that the connection flexibility increases the building deflections at specified loads, but the strength is only marginally affected. The dynamic analyses results show an increase in deflections and also generally an increase in column bending moments due to connection flexibility and the associated strength.     

Estimating effectiveness of state-of-the-art detectors and automatic sprinklers on life safety in residential occupancies

The report provides a qualitative assessment of the life safety impact of early warning fire detection and automatic sprinkler technology in residential occupancies. This assessment is based on the results of full-scale studies and statistics on residential fire fatalities from the NFIRS data base. Estimates of the impact of three alternatives, smoke detectors, standard automatic sprinklers, and residential sprinklers, are provided for major fire hazard scenarios in residential occupancies. The results of this study indicate that significant life safety benefits can be derived from broad application of detectors and sprinklers in all residential buildings. National Bureau of Standards Note: This is a condensed version of the more detailed document NBSIR 84-2819 bearing the same title as above. The document is available in limited quantities from the National Bureau of Standards or it may be purchased through National Technical Information Services (NTIS). Reference: Edward K. Budnick, “Estimating Effectiveness of State-of-the-Art Detectors and Automatic Sprinklers on Life Safety in Residential Occupancies.” Fire Technology, Vol. 20, No. 3, August 1984, p. 5.