Interaction of glucose and cellulose with hydrogen sulphide and polysulphides     

M.E.C. Moers  J.W. de Leeuw  H.C. Cox  P.A. Schenck 《Organic Geochemistry》1988,13(4-6)

This paper describes simulation experiments in which glucose and cellulose were reacted with polysulphide and hydrogen sulphide at ambient temperatures in an aqueous environment. Organic sulphur containing compounds were formed that yield several thiophenes upon pyrolysis/evaporation. The experiments show that interaction of carbohydrates with hydrogen sulphide or polysulphides is a possible way for carbohydrates to react in very recent sediments. From the results of this study it can be concluded that carbohydrate carbon can be preserved in sediments in a form that is resistant to microbial attack and that will have a greater potential for survival during diagenesis than the carbohydrate precursor.  相似文献   

Responses of the tropospheric ozone and odd hydrogen radicals to column ozone change     

S. C. Liu  M. Trainer 《Journal of Atmospheric Chemistry》1988,6(3):221-233

The response of tropospheric ozone to a change in solar UV penetration due to perturbation on column ozone depends critically on the tropospheric NO _x (NO+NO₂) concentration. At high NO _x or a polluted area where there is net ozone production, a decrease in column ozone will increase the solar UV penetration to the troposphere and thus increase the tropospheric ozone concentration. However, the opposite will occur, for example, at a remote oceanic area where NO _x is so low that there is net ozone destruction. This finding may have important implication on the interpretation of the long term trend of tropospheric ozone. A change in column ozone will also induce change in tropospheric OH, HO₂, and H₂O₂ concentrations which are major oxidants in the troposphere. Thus, the oxidation capacity and, in turn, the abundances of many reduced gases will be perturbed. Our model calculations show that the change in OH, HO₂, and H₂O₂ concentrations are essentially independent of the NO _x concentration.  相似文献   

块状硫化物矿床的地球化学找矿标志   总被引：6，自引：0，他引：6  

王登红 《地质科技情报》1994,13(2):80-86

近年来国外发现了许多大型块状硫化物矿床，而我国进展还不大。原因之一是我们对这类矿床的地质特征，成矿条件尤其是找矿标志研究还不够。这是一类成矿物质通过热液作用在海底沉积而成的特殊矿床，故在找矿勘探讨既要研究沉积矿时形成的原生晕，又要研究热液经过围岩时蚀变而产生的次生晕?Ｍｎ晕，Ｔｌ，Ｈｇ，Ｂａ，Ａｓ和Ｚｎ等元素的异常，络合剂元素的富集，微量元素的分布，铅同位素，岩石化学异指数尤其是块状硫化物Ｃｕ矿中  相似文献   

北祁连块状硫化物矿床中矿石和主要矿石矿物地球化学特征     

黄玉春  邬介人  于浦生 《矿床地质》1994,13(1):61-74

对北祁连山白银矿田和郭密寺矿田中主要矿床的矿石和矿石矿物组分特征研究表明，由于各矿田的成矿条件和地球化学背景存在差异，造成不同矿床的矿石和矿石矿物元素组合各具特色。但作为同一类型矿床，它们之间又有很多共性，特别是同一矿田内各矿床的地球化学特征具有相似性和过渡性，反映了成矿条件变化的趋势。  相似文献   

电气石和水之间的氢同位素分馏   总被引：1，自引：0，他引：1  

钱雅倩  郭吉保 《地球学报》1994,15(Z1):189-196

作者对电气-水体系氢同位素平衡分馏和动力学分馏和动力学分馏开展了实验研究，丰富了羟基矿物氢同位素分馏资料。本文对该研究的实验技术、分析方法作了介绍，并对实验结果进行讨论与国外已有的该方面的资料作了对比。在800-650℃时电气石和水之间氢同位素平衡分馏系数与温度间线性关系为103lna电气石-水=-28.24（106/T2）+2.60；交换速率常数与温度间关系为lnk2=-0.19-6.70（103/T）  相似文献   

Determination of part-per-trillion levels of atmospheric dimethyl sulfide by isotope dilution gas chromatography/mass spectrometry     

Donald C. Thornton  Alan R. Bandy  Robert G. Ridgeway  Arthur R. Driedger III  Marija Lalevic 《Journal of Atmospheric Chemistry》1990,11(4):299-308

Stable isotopic dilution was applied to the determination of dimethyl sulfide (DMS) in ambient air at the low part-per-trillion by volume (pptrv) levels. Perdeuterated DMS was used as an internal standard in the gas chromatography/mass spectrometry determination. The isotopically labelled internal standard provided insensitivity to possible losses of DMS in sampling and analysis. The lower limit of detection (LLD) was 1 pptrv with a sample acquisition time of 2 min.  相似文献   

乳砷铅铜石的发现与研究   总被引：2，自引：0，他引：2  

赖来仁  李艺 《矿产与地质》1991,5(6):459-463

乳砷铅铜石发现于1984年,在广西德保和平桂等矿区的硫化物型矿床的氧化带铁帽中.对该矿物的物理、化学和X射线粉晶分析、红外光谱分析以及差热分析等方面进行了测试研究,其结果与国外已知数据基本一致.矿物呈淡黄绿或深绿色,细粒状或葡萄状,硬度H=4,比重D=5.35,透明,二轴晶负光性,2V大,Ng=1.9817,Nm=1.9703,NP=1.9584.化学成分为PbO 35.19,CuO 30.64,As_2O_5 30.09,FeO 0.28,ZnO 0.05,H_2O 4.10(%).相应的化学分子式为Cu_(2.96)Pb_(1.21)(AsO_4)_(2.01)(OH)_(2.31)·0.59H_2O.X射线粉晶数据与JCPDS26～1410卡基本一政,衍射强线为3.14(10),3.24(8),2.92(8),2.55(8),2.74(7),2.49(7),2.27(7),4.51(6),4.94(5),2.66(4),1.902(4),1.817(4).计算的晶胞参数为a=10.236(?).b=5.904(?),C=14.213(?),β=106.39°,z=4,单斜晶系;空间群为A2/a.红外吸收光谱波数为3440、1640、870、820、775、465和1100、590、557(cm~(-1));差热分析吸收峰为580、773、812、889、898(℃).  相似文献   

绿砷钡铁石在广西的发现     

赖来仁  李艺 《矿物学报》1991,(1)

本文研究了在广西德保铜锡矿床氧带化中发现的绿砷钡铁石,给出了它的物理性质、化学成分和晶胞参数等矿物学数据。  相似文献   

岩浆型铜镍硫化物矿床地质概念模型   总被引：4，自引：1，他引：4  

胡旺亮 《地球科学》1991,16(3):249-256

  相似文献   

宁南山区雹块氘含量的分析          下载免费PDF全文

杨颂禧  马伟  陈玉山 《大气科学》1991,15(3):24-30

由10个大雹块(长轴47—64mm)切片中的43个氘样分析得知:雹块的平均δD值为-93.8‰,其相应高度为海拔807m(-14.7℃),干生长层的平均δD值为-101.8‰,相应高度为8803m(-19.5℃),湿生长层的平均δD值为-91.5‰,相应高度为7413m(-11.4℃)。氘含量与冰晶平均长度之间有较好的统计关系。  相似文献