基于EOS/MODIS资料的沙尘遥感监测模型研究

在EOS MODIS资料可见光波段光谱特性的深入分析的基础上，提出了一种完全用MODIS可见光波段监测沙尘信息的技术方法。充分利用MODIS资料可见光范围波段划分细致的特点，构造了不同的光谱特征判别函数作为决策树的分支，最后用决策树法成功地对几次沙尘暴过程进行了沙尘信息遥感监测。结果表明，该方法具有良好的效果和实用性。     

为我国土壤科学的发展奋斗终生的李连捷院士

文章简述了李连捷先生为中国的土壤科学和为生产服务而奋斗的一生。20世纪40年代,他在去美国深造之前,就在国内到贵州、广西和华南的许多省区进行了大面积的土壤调查工作。新中国成立后,他欣然接受先后到黑龙江、青海和内蒙古等省区进行荒地资源垦殖的调查任务,并于50～60年代,先后参与和组织了对西藏、新疆等地多专业的大型综合考察。通过这些考察,为西部大开发摸清和积累了大批可贵的自然资源资料,为我国土壤的发生和分类、土地资源的合理利用以及国民经济的发展做出了积极贡献。李先生在他近半个世纪的教学工作中,为我国培养了大批土壤科学人才。他一生刚正不阿、高风亮节,为我们树立了学习的榜样。在李连捷先生逝世10周年之际,仅以此文表达对他的深切怀念。     

Simulation of artificial random field considering the temporal-spatial variation

Introduction For the seismic design of special structures such as nuclear power station, marine platform, long-span bridge and dam, generally the time-history response analysis of the structure under seismic excitation is imperative, which was coded in most seismic design codes. The earthquake records suitable for the seismic situation and site condition are necessary to be used as the seismic input in the dynamic analysis of structures. As a result of the limited observational condition of st…     

Seismic response predictions of multi‐span steel bridges through pushover analysis

In the new trend of seismic design methodology, the static pushover analysis is recommended for simple or regular structures whilst the time‐history analysis is recommended for complex structures. To this end, the applicable range of the pushover analysis has to be clarified. This study aims at investigating the applicability of pushover analysis to multi‐span continuous bridge systems with thin‐walled steel piers. The focus is concentrated on the response demand predictions in longitudinal or transverse directions. The pushover analysis procedure for such structures is firstly summarized and then parametric studies are carried out on bridges with different types of superstructure‐pier bearing connections. The considered parameters, such as piers' stiffness distribution and pier–0.5ptdeck stiffness ratio, are varied to cover both regular and irregular structures. Finally, the relation of the applicability of pushover analysis to different structural formats is demonstrated and a criterion based on the higher modal contribution is proposed to quantitatively specify the applicable range. Copyright © 2003 John Wiley & Sons, Ltd.     

松潘—甘孜造山带中丹巴地区变质岩的流体包裹体研究

对丹巴地区动热变质岩石英中的流体包裹体研究表明，第一类型包裹体为高密度CO2包裹体，与深层滑脱作用密切相关，其温度、压力可代表变质峰期的温压条件。第二类型包裹体为CO2－H2O包裹体，H2O含量增加，与变质峰期后的抬升作用有关。第三类型包裹体为NaCl－H2O包裹体，以H2O为主，与抬升作用引起的退变质作用有关。其形成温度依次降低，说明它们是在变质作用的不同阶段捕获的。     

壤中氧测量在找矿中的意义

随着科学技术的发展，壤中氧测量已具备应用于野外找矿的基本条件。本文通过野外壤中氧测量的找矿实例，对方法的理论依据、技术基础做了简要的阐述。介绍了壤中Ｏ２测量与壤中Ｒｎ，ＣＯ２测量配合在找矿中的成功应用，并认为：以积分形式采集数据的壤中氧方法具有方便、稳定的特点。     

Important Geological Factors Controlling the Formation of Gold Deposits in East China

The major gold deposits in east China are characterized by their occurrence in pre-Cambrian host metamorphic rocks,restriction in some specific stratigraphic-structural terranes,tendentious localization in ductile or ductile-brittle shear zones,association with the syntexis type granitoids,and significant remobilization,superimposition and enrichment by the later stage Mesozoic tectono-magmatic activities.     

硬质合金复合片齿钎具

运用力学原理研制成功了复合片齿钎头和复合片齿整钎，并批量投入市场。该系列钎具凿岩速度、寿命和硬质合金片齿有效利用率均显著优于片状和球齿钎具。     

Seismic performance evaluation of steel arch bridges against major earthquakes. Part 1: dynamic analysis approach

In this study the inelastic behavior of steel arch bridges subjected to strong ground motions from major earthquakes is investigated by dynamic analyses of a typical steel arch bridge using a three‐dimensional (3D) analytical model, since checking seismic performance against severe earthquakes is not usually performed when designing such kinds of bridge. The bridge considered is an upper‐deck steel arch bridge having a reinforced concrete (RC) deck, steel I‐section girders and steel arch ribs. The input ground motions are accelerograms which are modified ground motions based on the records from the 1995 Hyogoken‐Nanbu earthquake. Both the longitudinal and transverse dynamic characteristics of the bridge are studied by investigation of time‐history responses of the main parameters. It is found that seismic responses are small when subjected to the longitudinal excitation, but significantly large under the transverse ground motion due to plasticization formed in some segments such as arch rib ends and side pier bases where axial force levels are very high. Finally, a seismic performance evaluation method based on the response strain index is proposed for such steel bridge structures. Copyright © 2004 John Wiley & Sons, Ltd.