An Incremental Response Spectrum Analysis Procedure Based on Inelastic Spectral Displacements for Multi-Mode Seismic Performance Evaluation

The so-called Nonlinear Static Procedure (NSP) based on pushover analysis has been developed in the last decade as a practical engineering tool to estimate the inelastic response quantities in the framework of performance-based seismic evaluation of structures. However NSP suffers from a major drawback in that it is restricted with a single-mode response and therefore the procedure can be reliably applied only to the two-dimensional response of low-rise, regular buildings. Recognizing the continuously intensifying use of the pushover-based NSP in the engineering practice, the present paper attempts to develop a new pushover analysis procedure to cater for the multi-mode response in a practical and theoretically consistent manner. The proposed Incremental Response Spectrum Analysis (IRSA) procedure is based on the approximate development of the so-called modal capacity diagrams, which are defined as the backbone curves of the modal hysteresis loops. Modal capacity diagrams are used for the estimation of instantaneous modal inelastic spectral displacements in a piecewise linear process called pushover-history analysis. It is illustrated through an example analysis that the proposed IRSA procedure can estimate with a reasonable accuracy the peak inelastic response quantities of interest, such as story drift ratios and plastic hinge rotations as well as the story shears and overturning moments. A practical version of the procedure is also developed which is based on the code-specified smooth response spectrum and the well-known equal displacement rule. This revised version was published online in July 2006 with corrections to the Cover Date.     

数字填图技术在区域地质调查中应用实例--以民和试点图幅为例

文章根据2002年中国地调局在青海省民和幅进行区域地质调查数字填图技术试点,结合实践,详细介绍了数字填图技术在区域地质调查中从野外到至内以最终阶段成果的PRB过程,证明了区域地质调查填图数字化是切实可行的。     

京珠高速公路粤境北段路堑高边坡失稳防治研究

京珠高速公路粤境北段地形条件十分复杂，被世界银行专家称为“中国最具挑战性的公路项目”。文章介绍了针对此项目开展的路堑高边坡失稳防治研究情况，着重介绍了该项研究的技术路线，以及为预防路堑高边坡失稳开展的系列研究。即：①路堑高边坡工程地质条件；②按常规所做原设计的堑坡稳定性；③路堑高边坡设计方案；④路堑高边坡施工工艺；⑤动态监测；⑥动态设计。研究与设计施工密切配合，及时将研究成果应用到工程实践中，取得很好的效果。     

价格支持政策改革背景下中国玉米市场空间关联

玉米市场空间关联是反映玉米市场运行效率的关键指标,价格支持政策的实施及改革对玉米市场空间关联产生重要影响。本文基于中国省际玉米市场价格数据,分析了价格支持政策改革背景下玉米市场空间关联及其时变情况,并运用社会网络分析法刻画了玉米市场空间关联网络特征,最后,通过QAP分析考察了影响玉米市场空间关联的主要因素。研究发现：① 中国玉米市场总体空间关联程度较高,且近年来整体呈上升趋势,玉米临时收储政策的实施并未改变其上升趋势,但导致政策实施省份玉米市场与其他地区玉米市场间关联程度下降。② 玉米市场空间关联呈现多线程、复杂的网络结构形态,网络结构较为紧密、整体关联性强且较为稳定;中东部地区玉米消费量较大的省份在玉米市场空间关联网络中处于中心位置,在网络中扮演着中心行动者角色,而实施玉米支持政策的区域以及西部地区在玉米市场空间关联网络中影响力较小,处于边缘和弱势地位,扮演着边缘行动者角色。③ 地理位置邻接、市场距离、销区市场势力、信息传递效应以及实施临时收储政策是决定和影响玉米市场空间关联的主要因素,其中,销区市场势力及信息传递效应对玉米市场空间关联的影响不断上升。     

广西城市空气污染预报业务系统的建立

应用数值预报与动态统计预报相结合的集成预报技术方法,将城市大气污染数值预报(CAPPS)模式、动态统计模式、Sybase数据库、网页技术等有机地结合起来,建立广西城市空气污染预报系统,形成了流畅的集资料传输交换、预报模式运算、预报制作与发布于一体的气象系统和环保系统预报会商的综合业务工作平台,在广西气象台同时对南宁、桂林和北海的城市空气污染做出预报。将近两年的业务实践应用表明,所建立的空气污染预报系统性能稳定、技术成熟、自动化程度和预报准确率高．     

Source Parameters of Old Earthquakes: Semi-Automatic Digitization of Analog Records and Seismic Moment Assessment

Recovering seismic information contained in old analog records could increase our knowledge of seismic source characteristics and the seismicity of a region. This is particularly important in zones with low to moderate seismicity.To extract the available information, it is necessary to digitize the seismic records. This is not an easy task especially owing to the generally poor quality of the original records, with illegible or missing parts. However some exceptions were found in the records of a few seismological stations in Germany, Sweden and France.This paper presents an example of the recovering of source parameters and can be divided in two parts: the first one presents a simple semi-automatic technique for digitization of old analog seismic records, developed using commercial software on a PC; the second part describes the methodology of assessing the seismic moment, using empirical and theoretical relations, as well as the seismic source dimensions.The earthquake selected to illustrate this procedure is the 23 April 1909 Benavente (Portugal) earthquake. This earthquake occurred in the Lower Tagus Valley region and caused great destruction in the meizoseismal area. It is the biggest earthquake that occurred during this century in the central part of the country and its magnitude has been estimated between 6.6 and 7.6.The digitization procedure allowed the recovery of seismic information contained in old analog records, in particular, the seismic moment estimation. The results obtained indicated that 7.6 was a very high value for the magnitude of the 23 April 1909 earthquake, suggesting that the magnitude reported in the Portuguese catalogue is overestimated. The estimated moment magnitude is 6.0.     

Use of double mass curves in hydrologic benefit evaluations

Environmental change resulting from intensified human interventions and climate change has impacted the hydrological function of many large river systems, largely altering the production and transport of run‐off and sediment. It is thus vital to quantitatively evaluate the influence of climate change and human activities on streamflow and sediment discharge. Water balance equations, hydrological models, and comparative analyses are commonly used to fulfil this need. Double mass curves (DMCs), being one useful method for comparative analyses, are characterized by low data requirements and high transferability, and thus more practical than water balance equations and hydrological models for hydrologic benefit evaluations. However, the detailed derivation procedure of the DMC has, to date, yet been described in literature. Moreover, in previous studies, changing points of the DMC were determined either rather empirically or as the changing point of streamflow or sediment discharge (i.e., precipitation was not considered). Hence, the changing point detected may be subject to inaccuracies. This paper, for the first time, comprehensively detailed the derivation procedure of the DMC; a new way was proposed to quantitatively examine the changing point of the DMC; an example was also given to demonstrate the use of the DMC in the hydrologic benefit evaluation. It is hopeful that the method given in our paper will be widely adopted by future studies as a standard procedure to derive and use the DMC.     

Artificial neural network-based storm surge forecast model: Practical application to Sakai Minato,Japan

The present study describes a novel way of a systematic and objective selection procedure for the development of an Artificial Neural Network-based storm Surge Forecast Model (ANN-SFM) with the 5, 12 and 24 h-lead times and its application to Sakai Minato area on the Tottori coast, Japan. The selection procedure guides how to determine the superiority of the best performing model in terms of the appropriate combination of unit number in the hidden layer and parameter in the input layer. In the application of ANN-SFM to Sakai Minato, it is found that the best 5 and 12 h-forecast ANN-SFMs are established with the most suitable set of 70 units (the number of hidden neurons) and the input components of surge level, sea level pressure, the depression rate of sea level pressure, longitude, latitude, central atmospheric pressure and highest wind speed. The best 24 h-forecast ANN-SFM is determined with 160 units and the input parameters of surge level, sea level pressure, the depression rate of sea level pressure, longitude and latitude. The proposed method of the selection procedure is able to be adaptable to other coastal locations for the development of the artificial neural network-based storm surge forecast model as establishing the superiority of the most relevant set combining unit numbers and input parameters.     

一种基于E-Key及Web页面监控的网站防篡改机制研究

通过监控Web页面文件变化和利用E-Key数字证书提高操作安全的网站防篡改机制,可以有效减少甚至消除由于网页遭遇篡改而给企业造成负面影响的目的.特殊设计的Web页面访问过滤监控程序通过计算,比对摘要,可以及时发现被篡改页面并执行删除操作和通知Web页面文件监控程序.Web页面文件监控程序立即停止Web服务,并删除变化文件.Web页面文件监控程序定期向Web页面安全管理服务程序发送心跳包,Web页面安全管理服务程序通过对心跳包的实时监测监控文件变化情况,并及时进行修复还原和报警,同时进行文件更新管理以及文件及其摘要备份.客户端安全控件实现操作者E-Key数字证书和服务器证书间的双向认证,确保web管理者远程操作过程的安全性.