HEAVY METAL POLLUTION IN SURFACE SEDIMENTS COLLECTED FROM DRAINAGES RECEIVING DIFFERENT ANTHROPOGENIC SOURCES FROM PENINSULAR MALAYSIA

Surface drainage sediments were collected, between January and April in 2005, from 6 sampling sites in Peninsular Malaysia suspected to have received different anthropogenic sources. These drainages included sites near a petrochemical plant, an electronic factory, a metal factory and 2 townships in addition to a relatively unpolluted site (a reference site). Based on the aqua-regia method, the metal concentrations for all the sampling sites except for the agricultural site (reference site) at Sg. Benut were between 60.92-1 019 μg/g dry weight for copper (Cu), 65.32-1 266.6μg/g dry weight for plumbum (Pb), 1.46-15.93 μg/g dry weight for cadmium (Cd), 330.10-484.14 μg/g dry weight for zinc (Zn) and 47.03-120.90 μg/g dry weight for nickel (Ni). All of these ranges were significantly (p< 0.05) higher than those (Cu: 8.77 μg/g; Pb: 57.42 μg/g; Cd: 0.96 μg/g; Zn: 68.21 μg/g; and Ni: 17.87 μg/g) of the reference site at Sg. Benut that only received agricultural disposal. The concentrations for the 5 metals from all the sites (except for the reference site) were higher than the Sediment Quality Values for Hong Kong by Chapman et al (1999) for the 5 metals. Based on the sequential extraction technique, 3 geochemical fractions [easily, freely leachable and exchangeable (EFLE), acid-reducible and oxidisable-organic] were also useful in identifying these polluted sites. The elevated metal concentrations found in the sediments might be related to point sources of industrial effluent and urban waste. Hence, the results emphasized the necessity for the treatment of effluents into this drainage area. As part of the effort to control illegal discharges and dumping into drainages, public awareness should be enhanced.     

海洋昏暗带微生物为碳沉积“把关”

海洋在全球碳循环中起着极为重要的作用,能够吸收大约一半由人类活动产生的温室气体,而其中大部分反应都发生在海洋表面以下100米的区域之内。海洋中多种浮游植物能够通过光合作用捕获碳,而当它们死后,会穿过海洋的“昏暗带”沉至永远漆黑的海底。然而,美国科学家进行的一项最新研究表明,海洋“昏暗带”的生物活动实际上是碳沉积的“把关人”,决定着浮游植物捕获的碳被永远存储于海底,还是很快又再回到海洋表层。     

Measuring the Fundamental Parameters of Hot Hydrogen－Rich White Dwarfs

This review considers the observations of hot, hydrogen-rich white dwarf stars, with particular reference to measurements of temperature, surface gravity and composition. Spectroscopic data from a variety of wavelength ranges are required for this work and, in particular, the important contributions from optical, ultraviolet and extreme ultraviolet studies are discussed. Using the values of Tefr and log g determined for an individual white dwarf, estimates of mass and radius might be derived from the theoretical mass-radius relation. The issue of the accuracy of the theoretical mass-radius calculations and the prospects for making empirical tests using observational data are outlined.     

低渗透储层微流动机理及应用进展综述

低渗透储层具有孔喉细小、孔隙结构复杂、比表面积大,黏土矿物类型丰富等特点,这些特点致使流体在低渗透储层中流动会产生强烈的微流动效应。微流动效应主要包括稀薄效应和不连续效应、表面优势效应、低雷诺数多流态效应、多尺度多相态效应等,这些特殊效应将影响描述流体流动的微分方程及边界状态。孔隙结构特征、黏土矿物产状、润湿性、岩石矿物荷电性等是低渗透储层微流动的影响因素,通过控制这些因素,可以改变流体在低渗透储层中的流动特征,从而控制油、气、水产量。目前已经形成了界面修饰技术、电化学驱油等采油新技术。以微流动机理为基础,结合孔隙结构特征,找出影响低渗透储层流体流动的主控因素,采用具有针对性的开采技术将成为高效开发低渗透油气资源的有效途径。     

Polarimetric entropy of the ocean surface with a two-scale scattering model

The relationships among an ocean wave spectrum,a fully polarimetric coherence matrix,and radar parameters are deduced with an electromagnetic wave theory.Furthermore,the relationship between the polarimetric entropy and ocean wave spectrum is established based on the definition of entropy and a twoscale scattering model of the ocean surface.It is the first time that the polarimetric entropy of the ocean surface is presented in theory.Meanwhile,the relationships among the fully polarimetric entropy and the parameters related to radar and ocean are discussed.The study is the basis of further monitoring targets on the ocean surface and deriving oceanic information with the entropy from the ocean surface.The contrast enhancement between human-made targets and the ocean surface with the entropy is presented with quad-pol airborne synthetic aperture radar（AIRSAR） data.     

热带气旋风场非对称性对表面海浪场的影响

用WAVEWATCHIII海浪模拟了5个不同风场结构的热带气旋下海浪平均要素和海浪方向谱来研究其对风场非对称性的响应。结果表明热带气旋诱发的海浪场对风场的非对称性很敏感。随着风场非对称性加强,有效波高除了左前象限增加以外在其他所有象限内都减小,且有效波高场的非对称性增强,并且非对称轴逆时针旋转,同时,有效波高最大值的位置向前移动。风场的非对称性对其他平均要素也有影响,尤其在左后象限最明显,例如平均波长,平均波向,波峰方向等。风场的非对称性对海浪谱的多峰性以及主导波的频率和传播方向都有很重要的影响。     

基于航空LiDAR数据提取建筑物边界的方法研究

激光测距是一项高效、精确的实现地表信息采集的技术。城市区域的高密度激光点云数据的获取使提取兴趣目标对象(建筑物、植被等)成为可能。本文提供一种利用航空激光雷达(LIDAR)数据提取建筑物边界的有效方法,该方法首先通过基于曲面拟合的滤波算法销减地形的影响,然后利用地物的纹理信息区分建筑物与非建筑物要素,最后通过一系列后处理,如小区域去除、矢量化等,最终提取出所需要的建筑物边界。实验表明本文提供的方法用于建筑物边界的提取效果理想。     

太阳表面震波能量与磁场强度的关系

过去的一系列研究表明在太阳光球表面,随着纵向磁场的增强,对应区域所观测到的震波能量随之降低.为了进一步研究震波和磁场的关系,使用日震和磁成像仪(Helioseismic and Magnetic Imager,HMI)的数据,通过对视向磁场进行势场外推得到磁场总强度,与震波能量进行关联.对一定总磁场区域的p模式震波能量拟合可以得到其随总磁场强度而变化的关系.研究证实了震波能量与磁场总强度有更强关联.不同活动区的结果表明p模式震波能量随着磁场总强度增加而下降的趋势在500 Gs以下非常接近,在500 Gs至1 000 Gs范围内有略微差别.并且p模式震波能量的对数与总磁场强度有较强的线性相关性.对比迈克尔逊多普勒成像仪(Michelson Doppler Imager,MDI)和HMI得到的结果时发现,虽然MDI观测的磁场结果整体会比HMI观测结果偏大,但归一化p模式震波能量与磁场强度的关系分析对比结果相差不大.     

科技看点

太空Space过去的火星和现在的地球科学家通过对发生在火星上一次古老火山爆发事件的研究后发现,这颗红色星球在数十亿年前拥有充沛的地表流水以及相对较厚的大气层,和地球的环境非常相似。研究工作是受到了一块在大约35亿年前的一次火山爆发中被抛射进入大气层的岩块的启发。这颗岩石碎块最终落回了火星表面,     

3D矿床建模技术在数字矿产勘查中的应用

为弥补现有数字矿床建模技术在地质矿产勘查处理和应用中的不足,从原始勘查数据建库及标准化、多指标单工程矿体自动圈定、基于语义识别的剖面矿体的连接与外推、矿体表面和品位建模、基于剖面矿体线框模型构建矿体表面模型及基于TIN+Octree数据结构和地质统计学理论建立矿体的空间属性模型等5个方面总结提出一套面向地质矿产勘查业务处理的矿床建模流程和总体技术解决方案.提高了地质矿产勘查研究精度,为进一步的矿山开采提供可靠的数据模型.