土钉支护弹塑性数值分析及稳定性探讨

用三维弹塑性有限元法对土钉支护进行了边开挖、边安装土钉和喷射混凝土面层的施工过程的数值模拟分析。通过一种强度折减技术探讨了土钉支护的稳定性。研究结果表明，施工过程中在不同的使用荷载作用下受力最大的土钉并不是一成不为的，因此，在土钉支护工程中不能随意地缩短某层土钉的长度。数值计算确定的潜在滑裂区和局部破坏区符合实际情况，认为钉体拔出是土钉支护最可能出现的内部失稳形式。     

Inelastic buildings with tuned mass dampers under moderate ground motions from distant earthquakes

The effectiveness of tuned mass dampers (TMD) in vibration control of buildings was investigated under moderate ground shaking caused by long‐distance earthquakes with frequency contents resembling the 1985 Mexico City (SCT) or the 1995 Bangkok ground motion. The elastic–perfectly plastic material behaviour was assumed for the main structure, with linear TMDs employed by virtue of their simplicity and robustness. The accumulated hysteretic energy dissipation affected by TMD was examined, and the ratio of the hysteretic energy absorption in the structure with TMD to that without it is proposed to be used, in conjunction with the peak displacement ratio, as a supplementary TMD performance index since it gives an indication of the accumulated damage induced in the inelastic structures. For the ground motions considered, TMD would be effective in reducing the hysteretic energy absorption demand in the critical storeys for buildings in the 1.8–2.8 s range. The consequence is reduction in damage of the buildings which would otherwise suffer heavy damage in the absence of TMD, resulting in economical restorability in the damage control limit state. This is of practical significance in view of the current trend toward performance‐based design. Copyright © 2001 John Wiley & Sons, Ltd.     

Trace Elements Analysis of Geological Samples by Laser Ablation Inductively Coupled Plasma Mass Spectrometry

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新疆头屯河流域水沙特性与减沙治理

本文通过对头屯河流域山区各水文实测水文，泥沙资料的分析比较，揭示了头屯河水沙运移规律，指出了头屯河上游产水，中游产沙，水沙异源的特点，进而地实才考察测量的基础上，结合流域自然特点，提出了工程，生物措施相结合的减沙治理方案和在流域不同地段的具本治理措施。     

鄂东铅锌矿床成矿中磷酸盐生物和非生物还原作用的有机地球化学研究

矿床产于三叠系大冶群碳酸盐岩中，有机质来自海相浮游生物和微生物。矿层中有机质发生成熟异常，已达过成熟作用早期。这得到镜质体反射率（Ro达4.6%）和矿物包裹体测温（均—温度达210℃）的证实。部分标本中有机质被微生物降解。硫同位素δ34S值大部分为正值，小部分为负值。综合研究表明在鄂东铅锌硫化物矿床的形成过程中，硫酸盐的生物和非生物还原作用，均具有十分重要的成矿意义。     

Estimation of abl Parameters Using the Vertical Velocity Measurements of an Acoustic Sounder

The friction velocity, the surface heat flux and the height of the Atmospheric Boundary Layer (ABL) are important parameters. In this work, vertical velocity variance ( _w ² ) and wind velocity structure parameter (C _v ² ) profiles estimated by acoustic sounder measurements are used, along with similarity relations, to estimate these parameters in the unstable Atmospheric Boundary Layer and the friction velocity in the stable one. The data were collected by two acoustic sounders with different height range and resolution under various atmospheric conditions (stability) and at two experimental sites in different terrain. The C _v ² profiles are estimated using gate difference of the vertical velocity measurements and the assumption of local isotropy. The vertical velocity data are corrected for the significant effects of noisy measurements and sampling volume averaging on the _w ² and C _v ² estimations using original techniques that are presented in this work. The results of the similarity method using acoustic sounder data are compared against estimates of the corresponding atmospheric parameters obtained from direct measurements. The comparison confirms the ability of the method to provide reasonably accurate estimates of these parameters especially in the middle of the day.     

PROGRAM FOR PROCESSING OF HISTORICAL LABORATORY DATA BASED ON FUZZY SET THEORY AS A TOOL FOR DECISION SUPPORT

A computer program(FEA)is presented for processing historical laboratory data.It performs on a list ofsample entries stored in a laboratory information management system.Using an algorithm which is basedon fuzzy set theory,FEA classifies the entries into a limited number of clusters called sample types.Theclassification is fully user-defined.The program transforms the historical data into a representation whichis more suitable for studying the performance of the laboratory or which can be used as preparation for asimulation project.     

GIS技术应用于城市防震减灾工作

介绍了基于GIS技术的“上海市防震减灾应急决策信息系统”,该系统由7个功能模块组合,主要有：地震地质基本信息,地震灾害快速评估子系统,地震应急决策信息子系统,信息查询,系统维护管理等。介绍了彩红外航片遥感等软件应用技术,并提出此系统需改进之处。