鄂尔多斯盆地东缘奥陶系碳酸盐岩碳氧同位素偏负原因探讨

奥陶系海相碳酸盐岩是鄂尔多斯盆地古生界的主要含气层系。经样品有效性评估并证明样品未受明显蚀变前提下,对碳、氧同位素的组成特征分析表明δ13C值和δ18O值变化大。本文探讨了δ13C与δ18O的影响因素及其偏负原因,认为土壤带中有机质增加是δ13C偏负主因,而淡水淋滤作用、埋藏作用及成岩作用则是造成δ18O偏负的重要因素。     

黄土高原春季大气气溶胶的质量浓度和矿物组成

2001年春季黄土高原沉降区长武大气气溶胶(TSP)的观测结果显示,其平均质量浓度为210μg/m3,其中4月份TSP平均浓度最高,为285μg/m3,5月份TSP平均浓度最低,为135μg/m3. 监测到的3次尘暴事件TSP浓度分别为402,46,453μg/m3,远高于春季平均浓度.矿物分析实验结果表明,石英、长石、碳酸盐和粘土矿物为其主要组成矿物.对比显示,尘暴粉尘与非尘暴粉尘在矿物组成上无显著性差异,且粘土矿物含量均在50%以上,表明长武粉尘气溶胶以较长距离的远源输入为主.结合空气气团轨迹分析结果,发现不同输送路径的尘暴粉尘其矿物组成上(方解石含量)存在差异,暗示着不同源区粉尘气溶胶矿物组成特征可能不同,并可用于粉尘源区的指示.     

塔中奥陶系油源岩碳、硫同位素对比分析

为进一步落实塔里木盆地塔中奥陶系碳酸盐岩油—源对比,确定烃源岩沉积环境,利用奥陶系不同层位产出原油碳、硫同位素分析对比。研究表明,寒武系干酪根δ~(13)C总体上应该要比奥陶系轻,寒武系原油不同δ~(13)C值应该来自寒武系不同有机相烃源岩。奥陶系原油族组分的δ~(13)C值特征表明,在奥陶系内确实普遍发生了硫酸还原作用,并受其影响下,寒武统和鹰山组原油中硫代金刚烷、苯并噻吩和二苯并噻吩类单体含硫化合物的δ~(34)S值远远大于寒武系干酪根δ~(34)S值,也大于奥陶纪海水的δ~(34)S值,而与寒武纪海水接近,因此,寒武系无机硫产生了并入。在奥陶系和中下寒武统中均发生了硫酸还原作用,并对其中的油气产生了影响。     

新场碳同位素特征

新场地区是四川盆地的主要产气区,文中研究了新场地区不同层位及由西向东的天然气碳同位素组成特征,大多数气样的δ^13C具有正碳同位素系列（δ^13C1〈δ^13C2〈δ^13C3〈δ^13C4）,显示天然气为典型的有机成因气,且是与煤型气相关的天然气,C1、C2、C3同位素分布直方图的主峰变化范围小,显示出天然气母质类型较为单一。随着干燥系数的增大,天然气的成熟度也随之增大。     

元素分析-同位素质谱法测定黄芪中碳、氮同位素比值及其在产地溯源中的应用

本文建立了采用元素分析-同位素质谱法(Element analysis-Isotope ratio mass spectrometer,EA-IRMS)测定黄芪中碳、氮稳定同位素比值的方法.该方法的稳定性和准确性均达到同位素比值测定的要求.利用该方法测定来自山西大同、陕西子洲、甘肃陇西和内蒙的黄芪样品的δ13C、δ15...     

川西南汉源地区白云岩的碳、氧同位素特征及成因初探

川西南汉源地区震旦系灯影组地层主要由白云岩组成,厚度1370余米。经研究发现该地区白云岩碳、氧同位素值相对较集中,而且偏重。1δ3C值介于0.1‰-2.7‰之间,平均值为1.08‰;1δ8O值介于-2.3‰--5.3‰之间,平均值为-4.21‰。碳、氧同位素值可以间接反映成岩环境。通过计算得出古盐度Z值大于120,成岩平均温度为37.3℃,并且白云岩的有序度值偏高,因此判定该地区白云岩的成因主要为蒸发模式、渗透回流模式以及埋藏模式成因。     

旬黄地区长6油层组碳酸盐岩胶结物特征及成因

碳酸盐矿物是旬黄地区长6砂岩中最主要的胶结物。主要包括方解石、铁方解石、白云石和铁白云石。镜下观察表明该地区长6砂岩碳酸盐胶结物可分为明显的早、中、晚三期,其主要呈充填粒间孔隙和泥微晶环边形式存在。通过对该地区长6油层组岩石薄片、碳氧同位素等测试分析,表明其主要碳酸盐胶结物为铁方解石。碳酸盐胶结物δ13CPDB值为-3.34‰~2.6‰,δ18OPDB值为-21.57‰~-12.06‰,其形成与有机酸的进入有关。     

川西地区须家河组天然气地球化学特征

通过对川西地区上三叠统须家河组地球化学特征的研究,其天然气组成主要以烃类气体为主,甲烷的含量在80%⁹1%,天然气组成特征为碳、氢同位素较轻,δ13C1介于-35‰91%,天然气组成特征为碳、氢同位素较轻,δ13C1介于-35‰^-32‰,δ13C2H6介于-25‰-32‰,δ13C2H6介于-25‰^-23‰;δDCH4介于-164‰-23‰;δDCH4介于-164‰^-154‰,δDC2H6介于-137‰-154‰,δDC2H6介于-137‰^-125‰;天然气的干燥系数(C1/C1-5)介于0.89-125‰;天然气的干燥系数(C1/C1-5)介于0.89⁰.98,普遍大于0.95,为干气。由于须家河组天然气中不含有H2S,天然气中甲烷碳同位素值与干燥系数之间成正相关关系,表明须家河组天然气属于典型的煤成气。     

气相色谱/燃烧炉/同位素比质谱方法检测尿液中睾酮的来源

目的:建立检测尿液中睾酮来源的气相色谱/燃烧炉/同位素比质谱方法。方法:尿液经萃取等前处理后,采用HPLC方法分离尿液中睾酮及其代谢产物和激素前体PD,收集流出组分;流出组分经气相色谱/燃烧炉/同位素比质谱方法测定睾酮及其代谢产物和PD的δ13C值。结果:阴性尿液样品中睾酮及其代谢产物的δ13C值与PD的δ13C值的差值小于3。阳性尿液样品中睾酮及其代谢产物的δ13C值与PD的δ13C值的差值大于3。结论:该方法可以用于检测尿液中睾酮的来源。     

前处理方法对微量沙尘气溶胶样品矿物实验结果的影响

为了探讨前处理方法对微量沙尘气溶胶样品矿物分析结果的影响,对2002年春季甘肃敦煌采集的3次沙尘暴样品分别进行了5次重复前处理和矿物分析实验研究.X射线衍射分析显示,8种沙尘气溶胶组成矿物的5次实验结果的标准偏差相对于平均值均较小.同时计算的石英、斜长石、方解石、伊利石、绿泥石和高岭石等沙尘气溶胶的主要组成矿物的相对标准偏差均小于10%,表明前处理方法对微量沙尘气溶胶样品的矿物分析结果影响较小.     

加油站风险源评估

在现代交通运输中,机动车扮演着重要的角色,伴随着我国的改革开放和十二五觃划的推行,国家和社会对机动车的需求日益剧增。机动车的动力由普及全国的加油站所提供,在如此注重安全的时代,我们急需重视加油站日益凸显出来安全风险。从加油站的罐区和加油区的各个组成部分分析加油站可能存在的风险,及时采取措施应对各种有可能存在的危险因素,提前做好检查防护工作,增强管理人员、工作人员与民众的安全防范意识,加大力度做好预防措施,降低加油站的事故风险。     

Sources of nitrous oxide in soils

Research to identify sources of nitrous oxide (N₂O) in soils has indicated that most, if not all, of the N₂O evolved from soils is produced by biological processes and that little, if any, is produced by chemical processes such as chemodenitrification. Early workers assumed that denitrification was the only biological process responsible for N₂O production in soils and that essentially all of the N₂O evolved from soils was produced through reduction of nitrate by denitrifying microorganisms under anaerobic conditions. It is now well established, however, that nitrifying microorganisms contribute significantly to emissions of N₂O from soils and that most of the N₂O evolved from aerobic soils treated with ammonium or ammonium-yielding fertilizers such as urea is produced during oxidation of ammonium to nitrate by these microorganisms. Support for the conclusion that chemoautotrophic nitrifiers such as Nitrosomonas europaea contribute significantly to production of N₂O in soils treated with N fertilizers has been provided by studies showing that N₂O emissions from such soils can be greatly reduced through addition of nitrification inhibitors such as nitrapyrin, which retard oxidation of ammonium by chemoautotrophic nitrifiers but do not retard reduction of nitrate by denitrifying microorganisms. This revised version was published online in August 2006 with corrections to the Cover Date.     

Sources of variability in laboratory weathering

A statistical study was conducted to determine the significance of the sources of variability in the laboratory (carbon arc) weathering of a light-stabilized polyester resin system. Color fastness of the resin was evaluated in terms of changes in total color, lightness, and chromaticity. Factors that significantly influenced the results were variability within castings and between batches of resin, location of the specimen within the exposure apparatus, and the storage time prior to testing. The carbon arc instrument provided a relatively insensitive test for evaluating a light-stabilized polymer system, chiefly because, with a stable polymer, small random variations in response become almost equal to the small change in color developed on exposure.     

Sources of Strain-Measurement Error in Flag-Based Extensometry

This paper examines the sources of error in strain measurement using flag-based extensometry that uses either scanning laser or electrooptical extensometers. These errors fall into two groups: errors in measuring the true gauge length of the specimen, which arise from the method of attachment of the flags, and errors arising from unanticipated distortions of the specimen during testing. The sources of errors of the first type include gauge-length errors from nonparallel flags and uncertainties in the true attachment point of the flag. During the test, strain-measurement errors of the second type can arise from horizontal translation of nonparallel flags, flag rotation that is induced by slippage, and flag motion from bending of the gauge length. Proper care can minimize the effect of these potential errors, so that flag-based extensometry can give accurate strain measurement, if appropriate precautions are taken. Measurements on silicon nitride indicate that the strain measurements are accurate to better than 10%.     

镁肥肥源及其应用

评述不同镁肥的生产和应用,包括镁肥肥源,我国生产镁肥的原料资源及生产厂家,近期研究开发动向及应用前景.     

室内主要大气污染物来源分析

从传统认识的角度来看,污染环境的重要根源就在于城乡交通业以及工业的排放。然而实质上,室内污染在整个大气污染中占据了相对较大的比例,甚至可达60%左右。由此可见,居室本身就构成了污染的根源所在,而室内环境与城市居民健康具有直接的内在联系。近些年来,城乡居民整体的生活水准都获得了全面提升,然而与之相应的室内污染却变得更严重,在这其中涉及到微生物与装修导致的室内污染。因此针对室内污染而言,有必要明确污染室内空气的重要污染物类型及其污染根源。结合室内主要大气污染物的基本特征,探求防控室内污染的可行对策。