某地平板玻璃原料用石英砂的提纯研究

某地石英矿砂通过磁选分离法、稀酸浸泡法处理后，矿砂不同程度地降低了铁、铝、钙镁的含量；采用磁选分离 稀酸浸泡法联合处理后，使该地石英砂的化学成分达到了优质的生产平板玻璃用硅质原料的国家标准。     

板块下的构造及地幔动力学

最新的全球地幔地震层析资料揭示了岩石圈板片可以俯冲到核幔边界，超地幔羽可以从核幔边界上升到地壳上部形成热点。在大陆板块汇聚边界，地幔地震层析图像不仅显示了岩石圈板片的超深俯冲，还保存了拆沉的岩石圈“化石”残片的重要信息。从地幔深部所获取的新资料为全地幔“单层对流“的新模式提供了依据。在介绍上述全球构造研究新动向的基础上，本文强调了研究岩石圈板块必须了解板块下的构造，探索岩石圈板块的驱动力应该从“岩石圈动力学”升华到“地幔动力学”，并提出了大陆板块汇聚边界地幔动力学研究的新思考。     

内蒙古达茂旗北部奥陶纪花岗岩类特征及其构造意义

研究区奥陶纪花岗岩分布于乌兰布拉格 -哥舍深大断裂 (槽台断裂 )以北 ,岩石类型主要有闪长岩、石英闪长岩、斜长花岗岩和花岗闪长岩。岩石中 Si O2 质量分数为 5 6.76%～ 69.2 4 % ,Al2 O3较高 (多 >1 6% ) ,富 Na2 O贫 K2 O,A/ CNK均 <1 .1 ,为准铝质的钙碱性岩石系列。稀土总量普遍较低 ,为 (63 .4 1～ 1 4 0 .61 )× 1 0 - 6 ,轻重稀土分馏强烈 ,铕异常不明显 (δEu=0 .95～1 .2 2 6)。痕量元素特征与典型的火山弧花岗岩相似。结合区域地质背景 ,认为该套花岗岩类为与洋壳消减有关的岛弧型花岗岩 ,岩浆起源于加厚陆壳的底部。从花岗岩的分布及迁移规律推测 ,华北陆块与其北缘增生带之间的早古生代洋壳可能是由南西向北东的斜向消减     

塔里木板块南缘早古生代沉积特征及构造背景探讨

塔里木板块南缘早古生代时期继承了震旦纪的古地理格局，处于浅海陆棚—半深海环境，沉积了一套海相碳酸盐岩和碎屑岩地层。根据区域地层划分、古生物化石和最新的同位素测年数据，确定了塔里林板块南缘地层时代为早古生代。通过沉积学和地球化学方法初步分析，确定了该地区为早古生代的大地构造背景—具有被动大陆边缘性质。因此，系统研究塔里木板块南缘早古生代沉积地层，对于重塑早生代以来该区板块构造格局及演化历史有重要地质意义。     

Review on study of seismotectonics in China

This paper reviews briefly the progresses made during the last four years (1999～2002) in study of seismotectonics in China, especially appraises the achievements in the fields of the crustal and upper mantle‘s structure, the active faults and tectonic setting of large earthquakes, the crustal deformation, and the numerical simulation. Most earth-quakes occurred in China belong to continental earthquakes. Therefore, Chinese seismologists pay more attention to the continental earthquakes. Based on improvements of the observation systems in China during the ninth Five-Year Plan, the studies on seismotectonics have achieved great progresses.     

NNR constraint in ITRF2000 and the new global plate motion model NNR-ITRF2000VEL

There are 54 sites employed by ITRF2000 for ITRF2000 orientation. The deficiencies are obvious. First, these sites cannot well represent the rotation rate of the earth crust because there is no selected site in five out of fourteen tectonic plates and three of fourteen plates only have one site each. Second, the total angular momentum of the crust is non-vanishing in ITRF2000, even though it is declared that No Net Rotation (NNR) with respect to NNR-NUVEL1A is imposed on ITRF2000 construction according to the documentations of ITRF2000. So the NNR condition in conventional terrestrial reference system (CTRS) realization cannot be satisfied in ITRF2000. In this paper, the criteria of site selection for estimating the Euler vectors are suggested; the Tisserand system constraint equation in ITRF construction is derived; and as a product, the global plate motions can be obtained from the ITRF2000 construction.     

ADV measurements of velocity distributions in a gravel‐bed flume

Velocity measurements carried out by an acoustic doppler velocimeter (ADV) in a rectangular laboratory ?ume having a gravel bed are presented. The velocity pro?les are measured in six verticals of the channel cross‐section having an increasing distance (from 4 to 38·5 cm) from the ?ume wall. The experimental runs are carried out for ?ve different bed arrangements, characterized by different concentrations of coarser elements, and for the two conditions of small‐ and large‐scale roughness. For both hydraulic conditions, the velocity measurements are ?rst used to test the applicability of the Dean pro?le and of the logarithmic pro?le corrected by a divergence function proposed in this paper. Then, for each value of the depth sediment ratio h/d₈₄, the non‐dimensional friction factor parameter is calculated by integration of the measured velocity distributions in the different verticals of the cross‐section. Finally a semi‐logarithmic ?ow resistance equation is empirically deduced. Copyright © 2003 John Wiley & Sons, Ltd.     

现代城市数字测图方法浅析

本文分析比较了目前城市大比例尺数字化测图中主要方法的优缺点，并为实现数字化地形图中不连续线、面状符号及复杂线状符号向GIS的自动化导入，针对电子平板法提出了基础线的概念。对全站仪草图法，提出在全站仪上加挂微型计算机，并用常规摄像方法代替草图。     

On Rhythmical Layering of Rocks Formed from Basaltic Magma

Formation of rhythmical layering in intrusive basic and ultrabasic rock bodies is explained in different ways, in particular, by the movement of microparticles (mineral clusters) of plagioclase and pyroxene within the basalt melt under the influence of thermal and gravitational forces. A model of cluster movement is proposed as a consequence of the forces appearing when ultrasonic elastic fluctuations pass through the melt. The model is based on fundamental dynamic equations. Depending on cluster density, wave parameters, and magmatic chamber size, in the melt there can form different combinations of rhythmically alternating layers of different composition.