西澳大利亚较老的前寒武纪地质年代学

在西澳大利亚,太古宙这个名词一般应用在早于2400Ma的岩层,这与最近由前寒武地层分会提出的2500Ma界线是有一定偏差的(James,《前寒武纪研究》,7,193—204页:1978)。无论应用那个标准,西澳大利亚地盾的二个最老部分—皮尔巴拉(Pilbara)和伊尔冈地块—在太古宙期间就已清楚确立。上述两个地块均以典型的绿岩—花岗岩类为主所组成,其中许多花岗岩类深成岩由含高比例火山岩同时形成的绿岩带所包     

有关皮尔巴拉地区地层和变形史的花岗岩侵入体Rb/Sr年龄测定

本研究项目包括澳大利亚西北部皮尔巴拉太古宙地块的两处地方。一处为瓦拉武山峡(Warrawie Gap),在那里,库甘溪(Coongan Creek)切过出露于下瓦拉沃纳群的库甘同斜东侧。集块岩、一些酸性火山岩和一处保存完好的枕状熔岩块状部分均被钠质花岗岩—花岗闪长岩和粉红色长石石英二长岩等深成岩所侵入。这些岩体有在形成主要穹丘时(或以前)所生成的片理—褶皱幕F-_2。横切的细晶岩并未受F_2的影响。用λ~(87)Rb     

热带气旋周围15米/秒风的半径和频率

1.引言海上交通常受台风海浪的影响。为了最大地保证船只的安全以及减少船只改变航线而付出的代价,我们必须预报出大风的水平范围。对于海面状态,地面风速为15米/秒的半径是一个重要的参数。本研究使用西北太平洋和西大西洋的无线电测风资料,计算了离台风和飓风中心各个距点上地面风≥15米/秒的发生概率。文章探讨了15米/秒等风速线与风暴强度和范围之间的关系,还讨论了沿     

“长生鸟计划”概述——介绍一个行星边界层试验研究计划

1.引言美国海洋大气局(NOAA)波传播实验室(WPL)和美国国家大气研究中心(NCAR)大气技术部(ATD)会同其它一些单位,于1978年9月在博尔德(Boulder)观象台(BAO)进行了一次大规模的野外试验,取名为“长生鸟计划”。该计划动用了装有探测仪器的飞机、地面气象网、雷达、激光雷达、声波探测器、微波辐射计、光学测风仪、无线电探空测风仪、定高气球以及为积累基本资料用的     

Heavy metal contamination in western Xiamen Bay sediments and its vicinity, China

Concentrations of selected heavy metals (Cu, Pb, Zn, Cd, Cr, Ni and Fe) in surface sediments from nine sites in western Xiamen Bay and its vicinity were studied in order to understand current metal contamination due to urbanization and economic development in Xiamen, China. The sediment samples were collected in December 2004 and July 2005 respectively in order to examine temporal variations. In this study, we found that heavy metal concentrations in surface sediments sampled in the western Xiamen Bay and adjacent Maluan Bay and Yuandang Lagoon varied from 19 to 97mg kg(-1) for Cu, 45 to 60mg kg(-1) for Pb, 65 to 223mg kg(-1) for Zn, 0.11 to 1.01mg kg(-1) for Cd, 37 to 134mg kg(-1) for Cr, 25 to 65mg kg(-1) for Ni and 3.08 to 4.81% for Fe. Although all metal concentrations in sediments meets Chinese National Standard Criteria for Marine Sediment Quality, both metal enrichment factors (EF) and geoaccumulation index (I(geo)) show that Pb contamination exists in the entire study area and contamination of other metals are also present in some locations depending on the sources, of which sewage outlets and commercial ports are the main sources of contaminants to the area. This study shows that using the sediment quality standard criteria only to assess sediments cannot properly reflect sediment contamination. A multiple approaches should be applied for the sediment quality assessment.     

翼龙类和驰龙类尾的前关节突和脉弧棒的趋同演化及翼龙类和鸟类尾部肌肉退化的平行模式

The caudal morphology of dromaeosaurid dinosaurs and most “rhamphorhynchoid” pterosaurs is a striking example of convergent evolution. In both groups, all but the most anterior five to seven caudal vertebrae have postzygopophyses that are elongate, equaling or exceeding the corresponding centra in length, and have bifurcating rod-shaped prezygopophyses that extend as much as seven times the length of the corresponding centra.     

MONITORING POLYNUCLEAR AROMATIC HYDROCARBONS IN SEDIMENT POREWATER BY SPMD

A new mimic biological Semi-permeable Membrane Device (SPMD) introduced for sampling organic pollutants yielded satisfactory results when it was frrst used as a passive sampler to concentrate and determine 16 kinds of polynuclear aromatic hydrocarbons (PAHs) by means of capillary GC on an HP 5890 GC-FID in coastal sediment perewater. The concentration of PAHs in sediment porewater for naphthalene(N), acenaphthlene(AL), acenaphthene (AE), fluorene (F), phenaphthene(P), anthracene(A), fluoranthene(FA), pyrene(Py), benzo[a]anthracene(B[a]A), chrysene(Chr), benzo[b] fluor- anthene(B[b]F), benzo[k]fluoranthene(B[k]F), benzo[a]pyrene(B[a]P),indeno[1,2,3,-cd]-Pyrene(I[123]P), dibenz[a,h]anthracene(D[ab]A) and benzo[g,h,i] perylene(B[ghi]P) were:50.36, under detection limits(UD), 18.19, 8.41, 8.40, 1.44, UD, 8.01, 524.15, 168.47, 50.13,123.66, 63.48, 27.40, 82.04 and 58,81 ng/L, respectively.     

DEPENDENCE BETWEEN FUSION TEMPERATURES AND CHEMICAL COMPONENTS OF A CERTAIN TYPE OF COAL USING CLASSICAL,NON-PARAMETRIC AND BOOTSTRAP TECHNIQUES

A statistical study of the dependence between various critical fusion temperatures of a certain kind ofcoal and its chemical components is carried out.As well as using classical dependence techniques(multiple,stepwise and PLS regression,principal components,canonical correlation,etc.)together withthe corresponding inference on the parameters of interest,non-parametric regression and bootstrapinference are also performed.     

RESOLUTION OF MULTICOMPONENT FLUORESCENT MIXTURES BY ANALYSIS OF THE EXCITATION-EMISSION-FREQUENCY ARRAY

Fluorescence lifetime provides a third independent dimension of information for the resolution of totalluminescence spectra of multicomponent mixtures.The incorporation of this parameter into theexcitation-emission matrix(EEM)by the phase modulation technique results in a three-dimensionalexcitation-emission-frequency array (EEFA).Multicomponent analysis based on the three-dimensionalEEFA brings a qualitative change for the resolved spectra,i.e.individual spectra can be uniquely resolved,which is impossible with any two-dimensional analysis.In this paper we present a method for analyzingthe EEFA.We show mathematically that with the three-dimensional analysis of the EEFA individualspectra and lifetimes can be obtained.Our algorithm is developed in mathematical detail and isdemonstrated by its application to a two-component mixture.     

格陵兰岛西南部Nassaq地区辉钼矿Re-Os年龄及意义

格陵兰矿产资源丰富,种类繁多,目前已探明的金属矿点(床)有800多个,具有巨大的找矿潜力,世界主要矿业公司多数对格陵兰的找矿与开发表现出积极态度。因此,选择典型地区开展深入研究对进一步找矿有重要的理论指导意义。格陵兰西南部的那萨克(Nassaq)地区交通较为便利,本文在对该地区系统的野外地质特征研究基础上,采集了含辉钼矿斜长角闪岩样品,并从中选择代表性样品,进行辉钼矿Re-Os年代学研究,为其成矿作用及相关问题的研究提供基本依据。该地区辉钼矿的形成年龄为2553 Ma,为新太古界末期的产物,其矿化是Qorqut花岗岩侵入时(2550Ma)所形成,在格陵兰西南部应重视Qorqut花岗岩有关的辉钼矿的找矿与评价工作。