橄榄石的后尖晶石相变研究进展

橄榄石在高温高压条件下分解为钙钛矿和方镁石(后尖晶石相变),这是地幔中最为重要的相变之一,被认为是660KM地震波速间断面的成因。现今所取得的重要进展表现在3个方面:①MG_2SI O_4的后尖晶石相变的原位X射线高温高压实验研究;②水、AL_2O_3以及压力标尺对后尖晶石相变的影响效应;③下地幔条件下地幔岩组分中的后尖晶石相变。在对研究进展进行概述的基础上,对目前存在的问题进行了分析并提出未来可能的研究方向。     

重力取样器取样技术研究

在湖泊环境研究中，淤泥质沉积物取样是一项很重要的工作，样品的取心率和原状性直接影响了环境研究的结果。重力取样器是获取湖泊、水库等水域浅层湖泊沉积物的一种经济有效、操作简单的常用工具。因此研究重力取样器的取样技术对环境研究具有积极的意义。研究了重力取样器的取样技术，并在此基础上成功设计了一种便携式的重力式取样器，非常适合环境研究机构的沉积物取样工作。     

陕西关中地区城镇等级规模结构分形研究

文章从分形理论在城镇体系研究中的应用入手，根据豪斯道夫（Hausdorff）维数，运用Zipf公式，对陕西省关中地区的城镇等级规模结构进行了分维测算。结果表明，该区域城镇体系具有分形特征，说明分形理论适合关中地区城镇等级规模结构的测算分析。并在分形研究的基础上分析了该区城镇规模结构的分布特点及其存在的问题。最后基于分形理论的测算与分析结果，提出了关中地区城镇体系结构和功能优化的建议。     

纳滤膜分离技术及其在盐湖卤水资源开发中的应用

介绍了纳滤膜分离技术原理及其主要应用领域,结合我国盐湖卤水资源的特点与开发利用现状,提出了将纳滤膜分离技术应用于卤水资源综合利用的设想。     

Mineral and fluid inclusions in zircon of UHP metamorphic rocks from the CCSD-main drill hole: A record of metamorphism and fluid activity

The Chinese Continental Scientific Drilling (CCSD) main drill hole (0–3000 m) in Donghai, southern Sulu orogen, consists of eclogite, paragneiss, orthogneiss, schist and garnet peridotite. Detailed investigations of Raman, cathodoluminescence, and microprobe analyses show that zircons from most eclogites, gneisses and schists have oscillatory zoned magmatic cores with low-pressure mineral inclusions of Qtz, Pl, Kf and Ap, and a metamorphic rim with relatively uniform luminescence and eclogite-facies mineral inclusions of Grt, Omp, Phn, Coe and Rt. The chemical compositions of the UHP metamorphic mineral inclusions in zircon are similar to those from the matrix of the host rocks. Similar UHP metamorphic P–T conditions of about 770 °C and 32 kbar were estimated from coexisting minerals in zircon and in the matrix. These observations suggest that all investigated lithologies experienced a joint in situ UHP metamorphism during continental deep subduction. In rare cases, magmatic cores of zircon contain coesite and omphacite inclusions and show patchy and irregular luminescence, implying that the cores have been largely altered possibly by fluid–mineral interaction during UHP metamorphism.

Abundant H₂O–CO₂, H₂O- or CO₂-dominated fluid inclusions with low to medium salinities occur isolated or clustered in the magmatic cores of some zircons, coexisting with low-P mineral inclusions. These fluid inclusions should have been trapped during magmatic crystallization and thus as primary. Only few H₂O- and/or CO₂-dominated fluid inclusions were found to occur together with UHP mineral inclusions in zircons of metamorphic origin, indicating that UHP metamorphism occurred under relatively dry conditions. The diversity in fluid inclusion populations in UHP rocks from different depths suggests a closed fluid system, without large-scale fluid migration during subduction and exhumation.     

快速城市化过程中城市土地覆被的时空动态特征

1990~2005年间,是广州市经济快速发展和城市景观变化最大的时期,以同时段TM影像解译得到广州市的土地覆被类型图,从数量结构、空间信息及位置转移和景观等方面,分析了广州市土地覆被的动态特征.数量结构的研究结果显示:在快速城市化过程中广州市的耕地、林地等自然资源的利用程度在加大,自1995年起,这种变化的趋势开始减缓;土地覆被类型之间的信息与位置的转移变化频繁,并且表现出空间位置分异的特征.景观特征指数分析结果表明:广州市城市土地覆被向破碎化方向发展,城市建设用地呈扩展之势.     

Estimating the minimum in-stream flow requirements via wetted perimeter method based on curvature and slope techniques

Under the assumptions of triangular cross section channel and uniform stable flow, an analytical solution of the minimum ecological in-stream flow requirement (MEIFR) is deduced. Based on the analytical solution, the uncertainty of the wetted perimeter method is analyzed by comparing the two techniques for the determination of the critical point on the relationship curve between wetted perimeter, P and discharge, Q. It is clearly shown that the results of MEIFR based on curvature technique (corresponding to the maximum curvature) and slope technique (slope being 1) are significantly different. On the P-Q curve, the slope of the critical point with the maximum curvature is 0.39 and the MEIFR varied prominently with the change of the slope threshold. This indicates that if a certain value of the slope threshold is not available for slope technique, curvature technique may be a better choice. By applying the analytical solution of MEIFR in the losing rivers of the Western Route South-to-North Water Transfer Project in China, the MEIFR value via curvature technique is 2.5%-23.7% of the multi-year average annual discharge, while that for slope technique is 11%-105.7%. General conclusions would rely on the more detailed research for all kinds of cross-sections.     

华南下寒武统镍钼矿层中铜铅锌矿物的发现及意义

华南扬子地块是我国古热水沉积成矿作用最为发育的地区之一,其热水沉积特性最早引起我国学者的关注。华南下寒武统黑色岩系中赋存多个与热水沉积成矿作用相关的大型、超大型重晶石矿床与N i-Mo-U-V多金属富集层。进一步研究分布在华南扬子地块黑色岩系中的金属、非金属矿床成因及其地球化学特征,对认识华南乃至全球晚震旦—早寒武世生物与环境演化有着十分重要的意义。本文对华南下寒武统镍-钼富集层矿石进行电子探针研究,识别出黄铜矿、黝铜矿等铜的独立矿物;闪锌矿等锌的独立矿物;方铅矿、白铅矿等铅的独立矿物。研究表明,在镍-钼矿石中这些矿物的发现为镍-钼矿层是热水沉积作用产物提供了直接的矿物学证据。     

图像数据挖掘软件原型系统的设计与开发

提出了图像数据挖掘软件原型系统的设计与开发的试验框架,阐述了其设计与开发方法,介绍了各个模块的功能、设计与开发情况。     

纹理映射失真处理中的LOD技术

纹理映射是计算机图形学中广泛应用的一项重要技术,纹理图像可以描述景物表面各点处的反射属性,模拟景物表面丰富的纹理细节,减少建模的工作量,提高计算机生成图形的真实性.但是由于纹理都为栅格图像,放大和缩小会产生一定程度的失真,所以要对纹理进行细节分层处理.文中主要介绍纹理的重采样和建立金字塔技术,提出减少纹理映射失真的方法.