固态萃取光度法测定痕量钛     

梁树权  肖宏展 《岩矿测试》1991,10(4):259-261

本文采用熔融联苯萃取8-羟基喹啉钛,继后溶固相于N,N-二甲基甲酰胺中,在390nm处测量吸光度。实验确定了各参数的最佳值,其摩尔吸光系数为7.9×10~3L·mol~(-1)·cm~(-1),一些干扰元素可以掩蔽。方法迅速、简便,用于测定铍铜合金中的痕量Ti,所得结果令人满意.  相似文献   

Li3N·LiI·LiCl锂快离子导体研究          下载免费PDF全文

贾永忠  杨金贤 《盐湖研究》1993,1(4):67-70

采用固态反应的方法制备Li_3N·LiI·LiCl快离子导体样品。使用X—射线衍射分析和差热分析的方法进行物相鉴定。电化学性能测试结果表明,样品具有较高的离子电导率,在100℃,其电导率可达10~(-4)_s/cm量级。样品的电导率与温度的关系很好地遵循Arrhenius方程。测得样品的电导活化能E_a为0.45eV。  相似文献   

地震信号内插与噪音剔除（一）   总被引：3，自引：0，他引：3       下载免费PDF全文

李庆忠 《地球物理学报》1987,30(5):514-531

信号内插与噪音剔除是相互有着有机联系的两个方面。首先讨论地震信号的内插方法,提出了一种“最佳内插算子”,从而导出了另一种“检噪算子”,它可以有效地把干扰波从记录中识别出来,并将其“剔除”出去。进而讨论空间域数据的内插问题--道内插问题。在一定的条件下,空间域数据内插与时间域内插是完全等效的,因此道内插也可以采用与时间域相同的“最佳内插算子”。地震记录上的干扰波其绝大部分表现为空间域的脉冲式干扰,所以用“检噪算子”在空间域作褶积,便能识别干扰,从而对干扰加以剔除。本文解决了一种迭代的剔除方法,取得了好的效果。  相似文献   

N同位素质谱分析及其数据处理   总被引：2，自引：0，他引：2  

韩友科  安娜 《地球学报》1997,18(Z1):290-292

本文论述了N同位素质谱分析原理和钢瓶高纯氮标定方法。同时对影响N同位素分析分馏因素作了相应讨论，指出钢瓶子高纯氮同位素标定，要用纯化后的大气氮定值。  相似文献   

Nitrogen isotope indicators of seasonal source variability to groundwater   总被引：5，自引：0，他引：5  

M. Z. Iqbal  N. C. Krothe  R. F. Spalding 《Environmental Geology》1997,32(3):210-218

 A nitrogen isotope study of soil water and groundwater in southern Indiana, USA, in 1991–1992 demonstrated considerable variations in nitrate degradation processes compared to an earlier investigation in 1986–1987. Although N-fertilizers were applied in May 1991, the δ¹⁵N values in soil water decreased in February 1992, indicating its delayed release into the system after substantial rainfall. The δ¹⁵N values of groundwater decreased from +12.3‰ in November 1991 to +11.3‰ in February 1992, and to +7.5‰ in March 1992. The increased residence time of nitrate in the soil resulted in increased denitrification, ammonia volatilization and plant uptake, and reduced threat to the groundwater quality. The 1986–1987 study in the area reported that excessive rainfall during the summer rapidly transported the nitrate to deeper horizons and drastically reduced volatilization and microbial reduction of nitrate, thus increasing the immediate threat to the groundwater quality in the area. The present study demonstrated that nitrogen isotopic signatures can be used to determine the effects of local soil type, rainfall, and land-use practices on the fate of nitrate in the subsurface. Received: 18 February 1997 · Accepted: 17 June 1997  相似文献   

Characteristics of magnetic and non-magnetic lag in the Cobar area, NSW     

S. Alipour  D.R. Cohen  A.C. Dunlop 《Journal of Geochemical Exploration》1997,58(1):15-28

Geochemical patterns from two lag anomalies in the Cobar region of central New South Wales are described. The region is semi-arid, deeply weathered and some areas are covered by variable thicknesses of aeolian and alluvial transported overburden.Lag morphology and mineralogy are related to landform. In erosional landforms the surface is covered by lag, which is composed of coarse fragments derived locally from bedrock and displays varying degrees of ferruginization, together with a range of secondary pisoids. In depositional landforms the lag is less abundant and contains more pisoids. Deflation by sheetwash may lead to lag being partially buried by alluvium. In a large proportion of pisoid lag, hematite and goethite have been converted to maghemite, allowing ready separation into magnetic and non-magnetic fractions. The non-magnetic fraction is dominated by the lithic lag whereas the magnetic fraction is dominated by pisoid lag.The magnetic and non-magnetic components of the 2–11 mm lag fraction, milled to < 75 μm and subjected to HF-HNO₃-HClO₄ attack, give rise to distinct geochemical patterns at targets related to a variant of the Cobar style of Pb-Zn mineralization with variable silicification and to Zn mineralization in a swarm of quartz and carbonate veinlets. The patterns are influenced by metal source, lag type, surface chemical conditions and landtbrm. Differences in the correlation between metal contents in the magnetic and non-magnetic lag components, and between trace elements and Fe. indicate variable loss of Cu and Zn from the magnetic lag at some targets but retention of Pb. The presence of a readily cxtractable base metal component in the lag has implications for detecting anomalies in transported cover in the region.  相似文献   

蔗渣生物质炭对喀斯特农田石灰性土壤氮转化过程的短期影响     

赖倩倩  杨霖  秦兴华  田伟  伍延正  汤水荣  解钰  Christoph Müller  孟磊 《中国岩溶》2019,38(3):450-457

生物质炭对于土壤中不同形态氮库的含量影响已有较多研究,但对西南喀斯特区石灰性土壤氮素形态,尤其是控制氮素形态的转化过程研究较为缺乏。本研究设置土壤中添加1%(C1)和3%(C2)蔗渣生物质炭2个用量水平,并以不施用蔗渣生物质炭作为对照(CK),共3个处理,通过 15 NH 4 NO 3 和NH^15 4 NO 3 成对标记技术,结合MCMC氮素转化模型研究了不同用量的蔗渣生物质炭对石灰性土壤氮转化过程的短期影响,为该地区蔗渣资源化利用和土壤氮保持提供理论支撑。结果表明,与CK相比,添加蔗渣生物质炭能够快速提高土壤pH和有机碳含量。添加生物质炭并没有显著改变土壤氮的矿化、铵态氮(NH^+ 4 )和硝态氮(NO^- 3 )的微生物同化和异养硝化速率,但NH^+ 4 吸附速率随生物质炭用量的增加而提高,以添加量最高的C2处理最大。添加生物质炭同样提高了土壤NH^+ 4 释放速率,但C1和C2处理的土壤NH^+ 4 释放速率并无显著性差异。与CK和C1处理相比,施用高量蔗渣生物质炭通过抑制自养硝化速率而显著降低了硝态氮净产生速率。这些结果表明,施用高量蔗渣生物质炭于石灰性土壤中可快速实现对NH^+ 4 吸附,降低自养硝化速率,减少NO^- 3 产生,从而降低了其损耗和淋失风险。  相似文献   

Organic Geochemistry of the Early Jurassic Oil Shale from the Shuanghu Area in Northern Tibet and the Early Toarcian Oceanic Anoxic Event   总被引：3，自引：0，他引：3  

CHEN Lan  YI Haisheng  HU Ruizhong  ZHONG Hong  ZOU Yanrong Open Laboratory of Ore Deposit Geochemistry  Institute of Geochemistry  Chinese Academy of Sciences  Guiyang  Guizhou  Graduate School of Chinese Academy of Sciences  Beijing Institute of Sedimentary Geology  Chengdu University of Technology  Chengdu  Sichuan State Key Laboratory of Organic Geochemistry  Guangzhou Institute of Geochemistry  Chinese Academy of Sciences  Guangzhou  Guangdong 《《地质学报》英文版》2005,79(3):392-397

This paper presents new geological and geochemical data from the Shuanghu area in northern Tibet, which recorded the Early Toarcian Oceanic Anoxic Event. The stratigraphic succession in the Shuanghu area consists mostly of grey to dark-colored alternating oil shales, marls and mudstones. Ammonite beds are found at the top of the Shuanghu oil shale section, which are principally of early Toarcian age, roughly within the Harplocearasfalciferrum Zone. Therefore,the oil shale strata at Shuanghu can be correlated with early Toarcian black shales distributing extensively in the European epicontinental seas that contain the records of an Oceanic Anoxic Event. Sedimentary organic matter of laminated shale anomalously rich in organic carbon across the Shuanghu area is characterized by high organic carbon contents, ranging from 1.8% to 26.1%. The carbon isotope curve displays the δ^13C values of the kerogen (δ^13Ckerogen) fluctuating from -26.22 to -23.53‰ PDB with a positive excursion close to 2.17‰, which, albeit significantly smaller, may also have been associated with other Early Toarcian Oceanic Anoxic Events (OAEs) in Europe. The organic atomic C/N ratios range between 6 and 43, and the curve of C/N ratios is consistent with that of the δ^13Ckerogen values. The biological assemblage,characterized by scarcity of benthic organisms and bloom of calcareous nannofossils (coccoliths), reveals high biological productivity in the surface water and an unfavorable environment for the benthic fauna in the bottom water during the Oceanic Anoxic Event. On the basis of organic geochemistry and characteristics of the biological assemblage, this study suggests that the carbon-isotope excursion is caused by the changes of sea level and productivity, and that the black shale deposition, especially oil shales, is related to the bloom and high productivity of coccoliths.  相似文献   

检测地震勘探微弱同相轴的混沌振子算法   总被引：20，自引：5，他引：15       下载免费PDF全文

李月  杨宝俊  赵雪平  张铭  林红波 《地球物理学报》2005,48(6):1428-1433

针对地震勘探资料湮没在随机噪声中的微弱同相轴问题提出基于混沌理论的混沌振子检测算法. 利用修正的Duffing_Holmes方程建立检测微弱同相轴的混沌振子系统,之后经过对同相轴的扫描处理,构成新子波等时间间隔序列W(t),与此同时对随机噪声也进行相同的截断. 截断的随机噪声在混沌振子系统中可以具有与周期信号相同的表现;经过大量仿真实验确定出满足通常地震勘探子波延续时间的使混沌振子检测子波不呈现周期相态的随机噪声截断时间范围. 选用与松辽盆地T1、T2反射层类似的子波函数并构成待检微弱周期信号,经过MATLAB仿真试验成功地检测出该弱信号,信噪比达到约-103dB.  相似文献   

河南箕山登封岩群变质中基性火山岩的地球化学及年代学研究   总被引：1，自引：0，他引：1  

薛良伟  原振雷  赵太平  陶自强 《地球化学》2005,34(1):57-65

对登封岩群 TTG杂岩区内的斜长角闪质表壳岩包体以及绿岩区的变质中基性火山岩对比研究表明 ,其主元素、微量元素、稀土元素和同位素地球化学特征等指示该区的变质中基性火山岩同时同源 ,具有由拉斑玄武岩向钙碱性玄武岩演变的趋势.登封岩群上下部 2件 Sm Nd等时线年龄极为一致 ,可以合并为一条等时线 ,年龄为 (2 512± 19) Ma,ε Nd(t)=2.40± 0.16.综合分析认为 ,箕山地区的登封岩群稍晚于嵩山地区 ,是在新太古代末期一个非常短暂的时间内形成的 ,形成于类似现代岛弧的构造环境.  相似文献