Bacterioplankton community composition in nearshore waters of the NW Black Sea during consecutive diatom and coccolithophorid blooms     

Elena Stoica  Gerhard J. Herndl 《Aquatic Sciences - Research Across Boundaries》2007,69(3):413-418

  相似文献   

弹性阻抗反演在塔里木油田吉南地区储层预测中的应用   总被引：1，自引：2，他引：1  

杨金华  李国发  刘洋  姜卫东 《应用地球物理》2007,4(3)

  相似文献   

Preliminary paleomagnetic dating of the metalliferous (Zn–Pb rich), Stark black shale, Kansas City region, U.S.A.     

K. Kawasaki  D.T.A. Symons  R.M. Coveney  Jr. 《Journal of Geochemical Exploration》2006,89(1-3):174

The Stark metalliferous black shale is a member of the Dennis Formation, which is a cyclothemic limestone and shale unit in the Missourian (Upper Pennsylvanian) Kansas City Group. Paleomagnetic analysis of 96 specimens from 7 sites indicates that the characteristic remanent magnetization of the Stark Shale yields a Late Mississippian to Early Pennsylvanian age. This age is close to, but slightly older than, the Middle Pennsylvanian host rock age and implies that the metalliferous content of the shale is syngenetic in origin.  相似文献   

Studies of distribution, release and environmental influences of Fushun oil shale and its self-combustion     

Liping ZHANG Rongshu ZENG 《中国地球化学学报》2006,25(B08):38-39

Three dumping sites have been formed at the northern region of Fushun City, Liaoning Province, for a large number of gangues including much oil shale that had been piled onto ground as gangue during long-term coal exploitation at West Fushun Open-pit Mine. Under appropriate conditions, self-combustion occurs after long-term exposure of oil shale and consequently such phenomena could be found almost everywhere at the three dumping sites. Much polycyclic aromatic hydrocarbons （PAHs） must be generated through oil shale self-combustion, a kind of incomplete combustion. In this paper, in order to make clear the PAHs distribution in oil shale and its self-combustion and their potential effects on surrounding environment, coal, low-grade oil shale, high-grade oil shale, burning oil shale, burnt oil shale and shaly soil collected from West Fushun Open-Pit Mine and West Dumping Site were analyzed quantitatively in 16 US EPA priority PAHs for the first time. Results showed that 16 PAHs in all samples were less than those in some bitumites and carbonaceous coals and were as much as those in lignites and anthracites from some Chinese mining areas. Coal and low-grade oil shale were abundant in lower molecular-weighted PAHs in contrast to high-grade oil shale with rich higher molecular-weighted PAHs. They had more benzo[a] pyrene than the highest background value in soils in Liaoning Province. So PAHs in these crude oil shales could cause potential effects on environment. There were at least 5121.40 p.g/kg PAils generated and at least 3976.70 μg/kg PAHs released into environment in the period from combustion beginning to sampling on the basis of calculation. Furthermore, the concentrations of 3-4 ring PAHs among them were very high. Therefore it could be said that oil shale self-combustion aggravated the environmental impacts of PAHs in oil shale. The low concentrations of PAHs in shaly soil showed that much PAHs had been released through recultivation and biodegradation.  相似文献   

Geomicrobiological in-situ containment of uranium in subsurface and its long-term stability     

Won-Kyoung Ha Jong-Un Lee 《中国地球化学学报》2006,25(B08):110-111

Uranium is a redox-sensitive element. While U （Ⅵ）, the oxidized form of uranium, is soluble and thus mobile in groundwater, U （Ⅳ） readily forms UO2（s） and is precipitated. Recent geomicrobiological researches demonstrated that dissimilatory metal reducing bacteria can effectively remove uranium fi＇om contaminated groundwater by reducing soluble U （Ⅵ） to relatively insoluble U （Ⅳ）. This novel form of microbial reduction of U （Ⅵ） is reported to be much faster than abiological reduction. The objective of this work was to investigate U （Ⅵ） reduction by indigenous bacteria in uranium-bearing black shale sediment and to determine whether microbially-precipitated uranium has long-term stability in subsurface. Through this study, fundamental information on the effects of microorganisms on the fate of redox-sensitive elements in natural settings will be provided. Soil and sediment samples were collected from uranium-bearing black shale in the Dukpyung area in Korea. Microbial inoculum was prepared from soil and sediment slurry supernatant. The reactors were purged with N2 ： CO2 gas （80 ; 20） to maintain anaerobic condition. Glucose, acetate or lactate was added as an electron donor at a final concentration of 5 mM.  相似文献   

吉林省油页岩中铂族元素的化学特征及分配规律研究   总被引：2，自引：0，他引：2  

WANG Wen-ying  SU Ke  GAO Gui-mei  GAN Shu-cai  LIU Zhao-jun.College of Chemistry  Jilin University  Changchun  China 《吉林大学学报(地球科学版)》2006,(6)

采用电感耦合等离子体发射质谱仪(ICP MS)测定了吉林省油页岩中铂族元素的含量,并对油页岩中铂族元素的化学特征、与无机组分的相关性及其分布模式等进行了分析和阐述。通过油页岩中铂族元素的含量与地壳和中国东部出露地壳中铂族元素丰度的比较表明,Rh、RuI、r等元素相对富集,其中松原油页岩中RhI、r的含量约为地壳平均值的10倍。研究区油页岩中铂族元素以Pt Pd分配模式为典型特征,一般Pt的丰度大于Pd。油页岩中铂族元素与无机组成相关分析的结果表明,油页岩中铂族元素可能呈吸附态存在于高岭石、伊利石等粘土矿物中。  相似文献   

John Michael (‘Jake’) Hancock (1928-2004): a personal memoir     

W.J. Kennedy 《Proceedings of the Geologists' Association. Geologists' Association》2006,117(2):103-122

  相似文献   

Measuring wave propagation characteristics in artificial sand-clay mixtures     

G. Cockaerts  P. De Cooman 《Surveys in Geophysics》1994,15(5):495-513

Ultrasonic compressional (V _p ) and shear (V _s ) velocities have been measured on artificial sand-clay mixtures. The measurements were carried out in a drained triaxial load cell using a pulse transition method. The measuring device was equiped with a waveform storage facility. The investigated mixtures consisted mainly of kaolinite and quartz sand. Some mixtures also contained Na-montmorillonite, illites or quartz-flour. The acoustic behaviour was observed during a pressure increase up to 72 MPa vertical and 36 MPa horizontal pressure. At a given pressure,V _p andV _s in pure sand turned out to be similar to those in pure kaolinite. As predicted by the sand-clay model of Marion (1990), a velocity maximum corresponds to a minimum in total porosity. This porosity minimum marks the transition from a clayey sand to a sandy clay. It is not only reflected in bothV _p andV _s , but also in the quality of the received pulse. The effective tension of the received signal during 20µs after the first arrival, was used as an indication for P-wave pulse attenuation. This apparent attenuation decreases with increasing clay content and increases with increasing porosity. It is shown that clay mineralogy does not measurably affect wave velocities in clayey sands.  相似文献   

黑风暴的沙尘形成与输送参数化及中尺度数值试验   总被引：21，自引：3，他引：21  

刘春涛  程麟生 《气象学报》1997,55(6):726-739

西北地区典型黑风暴和强沙尘暴都是在特定大尺度环流背景和中尺度系统相互作用下发生和发展的，而中、低空强锋区相伴的强冷锋移经沙源充足的大沙漠区是黑风暴和强沙尘暴形成和发展的必要条件。为了研究黑风暴和沙尘暴的沙尘形成、输送及沉降机制，本文提出了一种沙尘源、汇项的参数化方案和一个沙尘输送方程，进而引入已有的ＭＭ４中尺度数值模式模拟系统；应用这个改进和发展的模式模拟系统基本成功地模拟了“９３．５”黑风暴的天气系统演变及其沙尘浓度的近地层和垂直分布以及沙尘的沉降与输送。模拟结果分析表明，用包括沙尘输送方程及其沙尘源、汇项参数化方案的中尺度数值模式来研究黑风暴的沙尘形成、输送和沉降机制是一种具有应用前景的方法。  相似文献   

白果园黑色岩系型银（钒）矿床沉积古环境与银（钒）初始富集   总被引：9，自引：0，他引：9  

庄汉平  卢家烂 《地质论评》1997,43(4):373-380

白果园银（钒）矿产于震旦系陡山沱组黑色色岩系中。矿床的地球化学和有机地球化学研究表明，黑色页岩含丰富以低等海生生物为主的腐泥型有机质，黑色页岩形成于局限的滞留海盆。  相似文献