On the land use in Three Gorges Reservoir area

In this study the arable land changes in two counties (Zigui and Xingshan) in the Three Gorges Reservoir area in China are investigated. The statistical data from the officially published statistical books are used to study these changes in the two counties during the past 50 years since 1949. The changes of arable land, changes of arable land per capita, and changes of multiple crop index in Zigui and Xingshan counties are examined. Using an index method, we conclude that the two counties are critical in the sustainable utilization of arable land.     

松潘-甘孜带：是弧前增生还是弧后消减?

根据多年在该区工作实践，认为松潘—甘孜造山带前身的巴颜喀拉盆地是羌塘—他念他翁晚古生代前缘弧之后的一系列多岛弧—盆系的一个大型弧后盆地。三叠纪时，围限此“三角形”盆地三条边缘的构造动力学作用方式具有不同的特征。其东侧为扬子西缘被动大陆边缘(D—T2)，中三叠晚期(拉丁期)转化为与华北和羌塘陆块有关的前陆盆地(T2—T3)，由于扬子陆块向西双向斜向俯冲作用，在其北侧和南侧边缘形成南昆仑和可可西里—甘孜—理塘俯冲消减杂岩。重建的地层层序和沉积地质特征显示巴颜喀拉盆地主体三叠系复理石沉积是周缘前陆盆地。     

压电双晶片双向大幅振动的探讨

通过压电陶瓷的逆压电效应对压电陶瓷双晶片在自动生产送料线上的应用研究，得出在二元系Ph(Ni1／3Nb2／3)O3-PhTiO3-PhZrO3的基础上作调整制作的压电双晶片。经运用在振动料斗上，作调频调幅控制。达到了压电双晶片振子结构，振子谐振频率为300Hz，当外加电压达300V时，振子偏转位移量大于1．7mm，故可作为一种理想的振动源。     

夏塞地区银、锡多金属矿成矿规律新认识

夏塞地区是西南三江(金沙江、澜仓江、怒江)地区东缘的一个重要成矿带，带内银、锡矿产责源十分丰富。本文认为其成矿物质来源于花岗岩体和地层，构造和岩体是区内的主要控矿因素，地壳演化与成矿作用关系十分密切，矿床类型为分布于岩体内接触带的矽卡岩型矿床和分布于岩体外接触带的热液型矿床。     

SHRIMP Age and Geochemistry of the Bikou Volcanic Terrane: Implications for Neoproterozoic Tectonics on the Northern Margin of the Yangtze Craton

The Bikou volcanic terrane is predominated by subalkaline tholeiitic lavas. Rock samples display lower initial ratios of Sr and Nd, 0.701248-0.704413 and 0.511080-0.512341 respectively. 207Pb and 208Pb are significantly enriched in the lavas. Most samples have positive εNd, which indicates that the magma was derived from EM-type mantle source, while a few samples with negative εNd indicate that there was contamination in the magma evolution. Magma differentiation is demonstrated by variations of LREE and LILE from depletion to enrichment. Additionally, normalized REE patterns and trace elements showed that lavas from the Bikou volcanic terrane have similar characteristics to those of basalts in arc settings caused by subduction and collision. Analyses showed that the Bikou volcanic terrane is a volcanic arc. New evidence proved that the Hengdan Group, north of the Bikou arc, is a turbidite terrane filling a forearc basin. Consequently, the Bikou volcanic terrane and the Hengdan turbidite terrane const     

灰色系统在地面沉降分析中的应用

该文将灰色系统理论引入地面沉降的研究之中。根据上海地面沉降的历史数据建立了上海地面沉降发展的GM(1,1)模型以及地面沉降与地下水位变化的映射GM(1,2)模型,最后运用所建立的模型对地面沉降的发展态势进行了预测。     

辽西朝阳盆地早白垩世一新的无齿翼龙化石

采自辽西朝阳盆地早白垩世九佛堂组的一翼龙化石被记述。化石材料是一接近完整骨架的无齿的翼龙，带有一不完全的头骨。作者将其归于翼手龙类(Pteroclactyloidea)，并建一新属、新种一无齿吉大翼龙(Jidapterus edentus gen．et sp．nov．)。     

烃类垂向微渗漏及其地表异常显示

烃类以微泡、水动力、扩散和渗透方式向地表迁移过程中,其效能、方式与油气藏的盖层、断裂与裂隙系统、储层的流体性质、地层压力等地质因素密切相关.通过对塔里木盆地雅克拉凝析气田上的地表、井中化探资料与地质资料的综合分析,认为该气田的井中垂向地球化学特征、控制烃类垂向微渗漏地质因素、地表化探异常显示之间呈现出很好的内在联系.     

地震参数计算与数据传输程序设计

设计了一种地震参数计算与数据传输程序，能够通过交互方式自动完成mb、mB、MS7、MS、ML五个震级及其他相关地震参数的计算，自动生成大震速报文件，直接连接PCU速报。不仅适用于数字地震仪同时也可以用于模拟仪器(如DD—1，DK—1)解决了SSB大震速报软件数据不易改动、容易出错、速度慢等问题。同时也完善了SSDP软件参数计算功能，提高了数字测震台的效能和速报水平，充分发挥了数字地震仪的优越性。     

Application of extended distinct element method with lattice model to collapse analysis of RC bridges

This paper proposes a simple lattice model for collapse analysis of RC bridges subjected to earthquakes by using the extended distinct element method (EDEM). In the model, a concrete element consists of lumped masses connected to one another by springs, and a reinforcement bar is represented by a discrete model or an integrated model. The proposed lattice model is simple but its parameters are reasonably defined. It has fewer element nodes and connecting springs, which will be of benefit by shortening the CPU time. The processes to determine the initial stiffness of concrete and steel springs, the parameters of the constitutive model and the fracture criteria for springs are described. A re‐contact spring model is also proposed to simulate the re‐contact of the concrete after fracture of springs; and a general grid searching method is used to decrease the CPU time for judging re‐contact after fracture. The lattice model is assessed by numerical simulations and experiments. As an application, a damaged single‐column pier subjected to the Kobe Earthquake in 1995 is analysed by EDEM with the proposed model. The simulation results indicate that the proposed model predicts well qualitatively the collapse process of RC bridges. Copyright © 2003 John Wiley & Sons, Ltd.