检索结果-南通市图书馆

Cesium accumulation by bacterium Thermus sp. TibetanG7:hints for biomineralization of cesium-bearing geyserite in hot springs in Tibet,china

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2007年第19期52卷 2680-2686页

作者： WANG HaiLei1,2.3. ZHENG MianPing1,2.3.& HUANG XiaoXing4 1 Institute of Mineral resources, Chinese Academy of Geological Sciences (CAGS), beijing 10003.,{3. {2. {3. for saline Lake and epithermal deposits, CAGS, beijing 10003.,{3. 3.Open Laboratory of saline Lake resourses and Environment, CAGS, beijing 10003.,{3. 4 Laboratory of Microbial resources, Institute of Microbiology, Chinese Academy of Sciences, {12. 100081,{3. Institute of Mineral resources Chinese Academy of Geological Sciences (CAGS) Beijing China r&d center for saline Lake and {2. {3. CAGS Beijing China Open Laboratory of saline Lake resourses and Environment CAGS Beijing China Laboratory of Microbial resources Institute of Microbiology Chinese Academy of Sciences Beijing China

The bacterium Thermus sp. TibetanG7, isolated from hot springs in Tibet, china, was examined for the ability to accumulate cesium from solutions. Environmental conditions were simulated and the effects of pH, K+, Na+ and K+-regimes were then studied to determine the possible role of the bacterium in the formation of cesium-bearing geyserite around these hot springs. In despite of the inhibition of K+ and Na+, the bacterium Thermus sp. TibetanG7 revealed noticeable accumulation of cesium from solutions, with maximum accumulations of 53.49 and 40.41 μmol Cesium/g cell dry weight in Na+ and K+ inhibition experiments, respectively. The accumulation of cesium by this microorganism is rapid, with 40%―50% accumulated within the first 5 min. K+-deficient cells showed a much higher capacity of cesium accu- mulation compared with K+-sufficient cells. It is evident that the bacteria within the genus thermus play a significant role in the cesium assembly. The formation of cesium-bearing geyserite is also considered.

关键词：铯元素沉积物硅华生物矿化

Carbon and Oxygen Stable Isotope Values and Microfossils at 41.4-4.5ka BP in Tai Co,Tibet,china,and Their Paleoclimatic Significance

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2011年第5期85卷 1036-1050+1052-1056+1051页

作者： ZHENG Mianping~(1,2.*),LIU Junying~(1,3.,MA Zhibang~(1,4),WANG Hailei~(1,2. and MA Nina~(1,2. 1 MLr Key Laboratory of {3. Lake resources and Environment,Institute of Mineral resources,CAGS, beijing 10003.,{2. 2.research and development {3. for {3. Lakes and epithermal deposits,Chinese Academy of Geological Sciences,beijing 10003.,{2. 3.Institute of Geology,Chinese Academy of Geological Sciences,beijing 10003.,{2. 4 Key Laboratory of Cenozoic Geology and Environment,Chinese Academy of Sciences,beijing 10002., china MLr Key Laboratory of saline Lake resources and Environment Institute of Mineral Resources CAGS Beijing 100037 China research and development center for saline Lakes and {2. {3. Chinese Academy of Geological Sciences Beijing 100037 China Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China Key Laboratory of Cenozoic Geology and Environment Chinese Academy of Sciences Beijing 100029 China

Two sedimentary sections were measured at Tai Co(Co means lake in Tibetan) in western Tibet,*** two sections are almost all composed of clay carbonate beds except in their lower parts where there are carbonized plants at>10 cm depths and dark-colored carbonate clay and clay at 50-70 cm depths,yielding abundant gastropods,ostracods,and *** carbon and oxygen stable isotope values of carbonate,ostracods,and charophytes and ecological features of microfossil communities indicate the following climatic change in the area from 41.4 to 4.5 ka BP:at 41.4-2..2.ka BP,the climate was relatively wet;at 2..2.2..5 ka BP,it was slightly warm-dry;at 2..5-2..5 ka BP,it was warm-wet;at 2..5-2..0 ka BP,it was slightly cold-wet;at 2..5-17.5 ka BP,it became cold abruptly and slightly wet,implying the climate of the last glacial maximum;at 17.5-16.0 ka BP,it was slightly cold-dry;at 16.0-11.8 ka BP,it was slightly warm-wet;at 11.8-10.4 ka BP,it was relatively cold-dry, roughly equivalent to the climate of the Younger dryas,and at 10.4 ka BP,the temperatures began to rise again;at 10.4-9.4 ka BP,it was slightly warm-wet;at 9.4-8.5 ka BP,there occurred short warm-wet oscillations;at 8.5-7.9 ka BP,it was slightly dry-cold,representing a strong temperature-lowering and drying event in the postglacial stage;at 7.8-6.3.ka BP,it was slightly warm-wet;at 6.3.4.5 ka BP,the climate tended to be cold-dry.4.5 ka BP recorded the maximum aridity since the late part of the late Pleistocene.

关键词： sedimentary environment index paleoclimatic changes late Pleistocene-Holocene(41.4-4.5 ka BP) Tai Co Tibet

Preliminary discussion of low-salinity hydrothermal fluid mineralization

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1999年第S2期44卷 141-143页

作者： ZHENG Mianping r & d center of saline Lake and {2. {3., Chinese Academy of Geological Sciences, beijing 10003., china r and d center of saline Lake and {2. {3. Chinese Academy of Geological Sciences Beijing 100037 China

rEVIEWING the history of the geology of mineral deposits, we may find that in the first fifty years of thetwentieth century the magmatic-hydrothermal theory of ore deposition was the most prevalent, whichgave impetus to the development of the geology of mineral deposits. In the 1960s, the drilling of theSalton Sea geothermal field, California, the United States, and discovery and study of the red Sea seafloor hot brines and large amounts of metal sulfides removed therefrom led to the rise of the brine theory ofmineral deposition, thus elucidating the origin of massive metal sulfides and promoted the discoveryand exploration of metal deposits. After the 1970s and the 1980s, through a study of the hydrothermal ore fluids of modern hotsprings. geologists came to realize that there exist low-salinity hydrothermal ore fluids other than

关键词： low-salinity hydrothermal fluid mineralization.

Evidence of the Pan-Lake Stage in the Period of 40-2. ka B.P. on the Qinghai-Tibet Plateau

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2000年第2期74卷 266-272页

作者： ZHENG Mianping, MENG Yifeng and Wei Lejunresearch & development center of saline Lake and {2. {3.,Chinese Academy of Geological Sciences, beijing 10003. Chinese Acad Geol Sci Res & Dev Ctr Saline Lake & Epithermal Deposits Beijing 100037 Peoples R China

The Qinghai-Tibet plateau is one of major saline lake regions in china, where saline lakes are widespread and constitute an important object of researches on the palaeoclimatic change in the region. On the basis of comprehensive investigations of the evolution of the lake's surface and sediments on the plateau, the authors have further demonstrated the existence of a pan-lake stage (river and lake flooding stage) on the Qinghai-Tibet plateau during the period of about 40+-{3. ka B.P. and analyzed the palaeoclimatic characteristics of the pan-lake period and relationships between the ancient monsoons and the uplift of the plateau since the beginning of the Quaternary.

关键词： Qinghai-Tibet plateau Late Pleistocene pan-lake event palaeoclimate

Approaches to improving critical current density of YBCO superconducting thick films deposited by electrophoresis

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2004年第2期47卷 165-172页

作者： ZHU Yabin1,2. ZHOU Yueliang2. LIU Zhen2. WANG Shufang2. CHEN Zhenghao2. L?Huibin2. YANG Guozhen2. XIAO Ling3. rEN Hongtao3. JIAO Yulei3.& ZHENG Minghui3.1. department of Physics, College of Science, beijing Jiaotong University, beijing 100044,{2. 2. Laboratory of Optical Physics, Institute of Physics and {3. for Condensed Matter Physics, Chinese Academy of Sciences, beijing 100080,{2. 3. General research Institute for Nonferrous Metals, beijing 100088,{2. Correspondence should be addressed to Zhu Yabin (email: ybzhu@***) department of Physics College of Science Beijing Jiaotong University Beijing China Laboratory of Optical Physics Institute of Physics and center for Condensed Matter Physics Chinese Academy of Sciences Beijing China General research Institute for Nonferrous Metals Beijing China

Fabrication of YBCO superconducting thick films by electrophoresis has been widely reported. However, the value of critical current density (J c) is far from what the practical application requires. The superconducting thick films are obtained using top-seeded melt growth method with different proportional Y2.aCuO5 (Y2.1) addition. High-pressure oxygen has been used in the annealing process to improve the uniformity of the oxygen content in the superconducting thick films. When 40mol% Y2.1 powder is added to the YBa2.u3.7–5 (Y12.) powder,J c for the superconducting thick film by approaches described above reaches 7.008×103.A/cm2.(77 K, 0 T), which is greater than the value ever reported.

关键词： YBCO thick films, electrophoretic deposition, melt-textured.

Internalization and distribution of three α1-adrenoceptor subtypes in HEK2.3. cells before and after agonist stimulation

在线全文

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2007年第3期28卷 359-366页

作者： Shu-yi WANG~2.Yao SONG~2.Ming XU~2.Qi-hua HE~3.Qi-de HAN~2.You-yi ZHANG~(2.4)2.Institute of Vascular Medicine,Peking University Third Hospital and Key Laboratory of Molecular Cardiovascular Sciences,Ministry of Education,beijing 100083.china 2.{2. of Medical Analysis,Peking University,Health Science {2.,beijing 100083.china Institute of Vascular Medicine Peking University Third Hospital and Key Laboratory of Molecular Cardiovascular Sciences Ministry of Education Beijing China center of Medical Analysis Peking University Health Science Center Beijing China

Aim:To examine the subcellular distribution of the 3.α1-adrenoceptor（α1-Ar）subtypes and their internalization and trafficking upon agonist stimulation in hu-man embryonic kidney 2.3. ***:Confocal real-time imaging,enzymelinked immunosorbent assay（ELISA）and whole cell[3.]-prazosin binding assaywere applied to detect the distribution and localization of the 3.α1B-Ar ***:α1A-Ar was found both on the cell surface and in the cytoplasm;α1B-Ar,however,was predominantly detected on the cell surface,while α1d-Ar wasdetected mainly in the intracellular *** stimulation withphenylephrine,localization changes were detected by confocal microscopy forα1A-and α1B-Ar, but the localization of α1d-Ar were *** promoted a more rapid internalization of α1B-Ar than α1A-Ar.α1d-Arinternalization was detected only by *** cell[3.]-prazosin bindingassay showed that α1A-Ar functional receptors were detected both on the cellsurface and in the cytoplasm;α1B-Ar,however,were detected predominantly onthe cell surface,while α1d-Ar were detected mainly in intracellular *** stimulation promoted internalization of α1A-and α***:Phenylephrine stimulation induced changes in the localization of the3.1-Ar.

关键词： adrenoceptor agonist stimulation confocal image enzyme-linked immunosorbent assay [~3.]-prazosin binding assay internalization subcellular distribution subtype

The study of two-color excitation upconversion of Pr(0.5)Yb(3.:ZBLAN

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2006年第2期49卷 169-177页

作者： CHEN Xiaobo1 & SONG Zengfu2.1. Applied Optics beijing Area Major Laboratory, Analysis and testing center, beijing Normal University, beijing 100875, china 2. Peking University, Physics School, beijing 100871, china Applied Optics beijing Area Major Laboratory Analysis and testing center Beijing Normal University Beijing China Physics School Peking University Beijing China

The excited state absorption upconversion of Pr(0.5)Yb(3.:ZBLAN glass material, under two-color excitation of the 960 nm semiconductor laser and the Xe lamp light simultaneously, is reported in this article. It was found that the upconversion emission spectra of 480.1, 519.0, 601.9 and 63..8 nm coincide with the common emission spectra. Meanwhile, the upconversion-excitation spectrum has three obvious peaks under two-color excitation, and they respectively correspond to the 856.0 nm upconversion ex-citation transition [1G4(Pr3.)→1I6(Pr3.) and 1G4(Pr3.)→3.1(Pr3.)], the 789.0 nm upconver-sion excitation transition 1G4(Pr3.)→3.2.Pr3.), and the 803.7 nm upconversion excitation transition 3.6(Pr3.)→1d2.Pr3.). The upconversion excitation transition 1G4(Pr3.)→1I6(Pr3.) is strong because its oscillator strength f = 2..040×10?6 is large, which results in a large peak appearing in the upconversion excitation spectrum. That is just the new interesting two-color excitation upconversion luminescence phenomenon of Pr(0.5)Yb(3.:ZBLAN induced by one laser and one continuous normal light simultaneously.

关键词： upconversion volumetric three-dimensional display two-color excitation.

distribution,formation and evolution of sand ridges on the East china Sea shelf

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2010年第3期53卷 822-828页

作者： ZHAO renBao 1,2.SUN HaiTao 3.WU YaSheng 3.&ZHAO ChuanFeng 1,2.1MOE Key Laboratory of Petroleum Engineering,china University of Petroleum,{3. 102.49,china 2.Enhanced Oil recovering research {3.,china University of Petroleum,{3. 102.49,china 3.aculty of Natural resource&Information Technology,china University of Petroleum,{3. 102.49,china MOE Key Laboratory of Petroleum Engineering China University of Petroleum Beijing China Enhanced Oil recovering research center China University of Petroleum Beijing China Faculty of Natural resource & Information Technology China University of Petroleum Beijing China

Influence of CO2.corrosion on reservoir mineralogical composition,pore structure and their mechanical characteristics was studied using Xrd,SEM,rock tri-axial machine and core flow experimental *** was found that the corrosion effect was mainly attributed to rock texture and structure,fluid composition and external dynamical conditions in the experimental *** cores with bedding structures,their bedding surfaces were the preferential corrosion regions,because micro-cracks would evolve at these surfaces in the pressure-releasing ***,for cores with massive structures controlled by stable water environment,the CO2.corrosion would result in pore enlargement and secondary pore *** gas velocity from outlet showed sharp increase in the injection process of CO2.H2. *** could be explained by two changes caused by *** was the opening and closure of *** other was particle *** the corrosion time increased,both tensile strength and compressive strength decreased,which confirmed decrease of cementation *** should also be noted that permeability increase and micro-cracks generation would pose damage to the capacity of CO2.geological storage.

关键词： carbon dioxide geological storage mineralization enhanced oil recovery corrosion

Carbon and hydrogen isotopic characteristics of natural gases from the Luliang and Baoshan basins in Yunnan Province, china

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2006年第9期49卷 938-946页

作者： XU Yongchang1, LIU Wenhui2. SHEN Ping1, WANG Wanchun1, WANG Xiaofeng1, Tenger1, YAN Yaomin3.& LIU ruobin3.1. Lanzhou center of Oil & Gas resources, Institute of Geology and Geophsics, Chinese Academy of Sciences, Lanzhou 73.000, china 2. research Institute of Petroleum Exploration and Production, SINOPEC, {2. 100083. china 3. South Branch of Petroleum Exploration and Production Company, SINOPEC, Kuming 650000, china Lanzhou center of Oil & Gas resources Institute of Geology and Geophsics Chinese Academy of Sciences Lanzhou China research Institute of Petroleum Exploration and Production SINOPEC Beijing China South Branch of Petroleum Exploration and Production Company SINOPEC Kuming China

The Luliang and Baoshan basins of Yunnan Province are two small-sizedcontinental oil/gas-bearing sedimentary basins, which were developed at the bases of theCarboniferous and devonian systems during the Late Tertiary, covering an area of 3.0} km^2.and 2.4km^2. respectively. Since the 1990s, there have been discovered small-sized natural gas pools inthese two basins. The natural gases are composed mainly of hydrocarbon gases, with nonhydrocarbonsaccounting for less than 2.. Of the hydrocarbon gases, methane accounts for more than 99%, and thecomponents above C_2.account for less than 0.2.. On the basis of previous studies of geologicalbackground, the composition of natural gases and their carbon isotopic composition, it has beendefined that these two gas pools are of bacterial origin. In this work we have comprehensivelymeasured the carbon and hydrogen isotopic composition of natural gases from these two basins andhave gone into the details of the mechanism of gas generation. The δ^(13.C_1 values of naturalgases from the Luliang Basin are within the range of -72.1 per thousand - -73.3.per thousand, andthe δd_(CH_4) values, -2.2.per thousand - -2.4 per thousand, indicating that the bacterial gasgeneration is dominated by the way of CO_2.reduction. It has been evidenced that undercontinental-facies fresh water conditions there did occur the CO_2.reduction as a process ofbacterial gas generation. The δ^(13.C_1 values of natural gases from the Baoshan Basin are withinthe range of - 62.5 per thousand - -63.5 per thousand, and the δd_(CH_4) values, -2.2.per thousand- -2.0 per thousand. These isotopic characteristics are fallen into transitional phase of acetatefermentation and CO_2.reduction as defined by Whiticar et al. (1986). An important discovery in theLuliang Basin is the carbon isotopic composition of ethane of purely biogenetic origin, i.e., itsδ^(13.C_2.values are within the range of - 61.2.per thousand - - 66.0 per thousand. These carbonisotopic values have been r

关键词： bacterial gas, carbon and hydrogen isotope, CO2 reduction, acetate fermentation.