检索结果-南通市图书馆

中国有色金属学会会刊：英文版 2009年第1期19卷 222-227页

作者：曾伟民邬长斌张汝兵胡培磊邱冠周顾帼华周洪波 School of Minerals Processing and Bioengineering Central South University Key laboratory of Biometallurgy Ministry of Education Central South University

A moderately thermophilic acidophilic iron-oxidizing bacterium ZW-1 was isolated from Dexing mine, Jiangxi Province, China. The morphological, biochemical and physiological characteristics, 16S rRNA sequence and bioleaching characterization of strain ZW-1 were studied. The optimum growth temperature is 48 ℃, and the optimum initial pH is 1.9. The strain can grow autotrophically by using ferrous iron or elemental sulfur as sole energy sources. The strain is also able to grow heterotrophically by using peptone and yeast extract powder, but not glucose. The cell density of strain ZW-1 can reach up to 1.02×108 /mL with addition of 0.4 g/L peptone. A phylogenetic tree was constructed by comparing with the published 16S rRNA sequences of the relative bacteria species. In the phylogenetic tree, strain ZW-1 is closely relative to Sulfobacilus acidophilus with more than 99% sequence similarity. The results of bioleaching experiments indicate that the strain could oxidize Fe2+ efficiently, and the maximum oxidizing rate is 0.295 g/(L·h). It could tolerate high concentration of Fe3+ and Cu2+ (35 g/L and 25 g/L, respectively). After 20 d, 44.6% of copper is extracted from chalcopyrite by using strain ZW-1 as inocula.

关键词：不锈钢电化学性能研究金属材料

Synthesis of[(C_5H_5)Y(η~2-PzMe_2)(μ-PzMe_2)]_2 and [Y(η~2-PzMe_2)_2(μ-PzMe_2)(μ-THF)]_2 and the insertion of Me_2SiO into the Y-N bond

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2001年第9期46卷 723-726页

作者： ZHOU Xigeng, ZHANG Libei, RUAN Ruyi, ZHANG Lixin , CAI Ruifang & WENG LinhongDepartment of Chemistry, Fudan University, Shanghai 200433, China State Key laboratory of elemental Organic Chemistry, Nankai University, Tianjin 300071, China Department of Chemistry Fudan University Shanghai China State Key laboratory of elemental Organic Chemistry Nankai University Tianjin China

3,5-Dimethylpyrazole (HPzMe2) reacted with (C5H5)3Y in THF to yield dinuclear complexes [(C5H5)Y-(η2-PzMe2)(μ-PzMe2)]2 ( I ) and [Y(η2-PzMe2)2(μ-PzMe2)-(μ-THF)]2 (II), revealing a new method for synthesizing tris(pyrazolate) complexes of lanthanide metals. The X-ray crystallographic analysis showed that complex II crystallizes in space group P 1 , with unit cell dimensions a = 1.0798(1), b = 1.0818(1), c = 1.1313(1) nm, a = 76.914(2)°,(B = 68.940(2)°, γ= 60.510(2)°, V = 1.0715(2) nm3, Z = 1. The final R factor is 0.0445. The investigation results showed that Me2SiO can only be inserted into the Y-N (bridging) bond of complex I to form [(C5H5)Y(η2-PzMe2)(μ-OSiMe2 PzMe2)]2 (Ⅲ), but cannot be inserted into the Y-N (bridging) bond of complex II due to the bulky crowding of the tetraple bridge structure.

关键词： yttrium pyrazolate crystal structure synthesis insertion cyclopentadienyl.

Synthesis of amorphous Ti-Al alloys by mechanical alloying of elemental powders

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2002年第4期12卷 610-614页

作者：张俊红黄伯云贺跃辉周科朝刘咏 central South University Changsha 410083 central South University State Key Laboratory for Powder Metallurgy Changsha 410083

Blended elemental powders with the nominal compositions (mole fraction, %) of Ti 54 Al 46 , Ti 52 Al 48 and Ti 50 Al 50 were mechanically alloyed in a planetary ball milling system for up to *** structure evolution in these powders was characterized by scanning electron microscope, X ray diffraction and differential thermal analysis techniques. It was found that elemental powders were progressively transformed into nanocrystalline Ti(Al) supersaturated solid solution, then into amorphous phase. With increasing Al content, the formation of a fully Ti(Al) supersaturated solid solution and amorphous phase were accelerated, which are attributed to the fine grain size. And the grain size condition for formation of amorphous phase in this system is ≤16?nm.

关键词：非晶合金 TiAl合金机械合金化粉末冶金

Sources, enrichment mechanisms, and resource effects of rare metal elements-enriched geothermal springs in Xizang, China

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第11期67卷 3476-3499页

作者： Fei XUE Hongbing TAN Xiying ZHANG Jinbao SU School of Earth Sciences and Engineering Hohai University Qinghai Provincial Key laboratory of Geology and Environment of Salt Lakes Qinghai Institute of Salt Lakes Chinese Academy of Sciences School of Oceanology Hohai University

Rare metals such as lithium(Li), rubidium(Rb), and cesium(Cs) are strategically crucial mineral resources for the development of emerging industries in China. Ensuring a stable long-term supply of these resources is essential. The geothermal systems in Xizang, China are well-developed, with a wide distribution of various types. Most high-temperature geothermal systems in Xizang are exceptionally enriched in rare metal elements(RMEs) and have the potential to become a new source of rare metals to secure China's strategic mineral resource supply in the future. A close relationship also exists between the geothermal system and the special salt lake resources on the Tibetan Plateau. Geothermal springs thus play a key role in the migration and enrichment of RMEs from deep to shallow parts of the crust, in the transition between endogenous and exogenous mineralization, and source-to-sink processes. However, the mechanisms of element enrichment and evolution in these springs have not been systematically discussed, and many theoretical issues remain to be investigated. Based on summarizing and analyzing previous research, this study employs hydrochemical and isotopic geochemistry methods to investigate typical geothermal springs across Xizang and explore the anomalous enrichment mechanism of RMEs, and the resource effects of geothermal springs. Comprehensive analysis shows that the total dissolved solids(TDS) and hydrochemical types of geothermal springs are similar to those of major geothermal fields worldwide, but the Tibetan springs are abnormally rich in Li(averaging5.48 mg/L), Rb(averaging 0.75 mg/L), and Cs(averaging 3.58 mg/L), which are hundreds to thousands of times more concentrated than natural waters. The distribution of these enriched geothermal springs is controlled by the Yarlung Zangbo suture zone and the extended N-S trending rifts, especially in the intersection zone of the two, where the geothermal springs are the most enriched. Based on the spatial distr

关键词： Geothermal springs Rare metal elements Enrichment mechanisms Salt lakes Tibetan Plateau

XANES AND XPS STUDIES OF PEROVSKITE-TYPE CATALYSTS

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 1988年第15期33卷 1251-1255页

作者：王其武姜明季明荣吴建新黄念祖 Department of Modern Chemistry University of Science and Technology of China Hefei central laboratory of Structure and elemental analysis University of Science and Terhnology of ChinaHefei General Electric Company USA

*** The perovskite-type compounds, as one kind of new functional materials has received more and more attention owing to their perfect crystal structure, unique electromagnetic properties, and high catalytic activitie... 详细信息

关键词： XANES XPS perovskite-type catalysts chemical shift

The photosynthetic oxygen evolution does not exclude the important role and contribution of bicarbonate photolysis

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2024年第1期43卷 174-179页

作者： Yanyou Wu Shaogang Guo State Key laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081People’s Republic of China University of Chinese Academy of Sciences Beijing 100049People’s Republic of China

Photosynthesis is the most important biochemical reaction on Earth. It has co-evolved and developed with the Earth, driving the biogeochemical cycle of all elements on the planet and serving as the only chemical process in nature that can convert light energy into chemical energy. Some heavy oxygen isotopic(^(18)O) labeling experiments have"conclusively" demonstrated that the oxygen released by photosynthesis comes only from water and are written into textbooks. However, it is not difficult to find that bicarbonate has never been excluded from the direct substrate of photosynthesis from beginning to end during the history of photosynthesis research. No convincing mechanism can be used to explain photosynthetic oxygen evolution solely from water photolysis. The bicarbonate effect, the Dole effect, the thermodynamic convenience of bicarbonate photolysis, the crystal structure characteristics of photosystem Ⅱ, and the reinterpretation of heavy oxygen isotopic labeling(^(18)O)experiments all indicate that the photosynthetic oxygen evolution does not exclude the important role and contribution of bicarbonate photolysis. The recently proposed view that bicarbonate photolysis is the premise of water photolysis, bicarbonate photolysis and water photolysis work together with a 1:1(mol/mol) stoichiometric relationship, and the stoichiometric relationship between oxygen and carbon dioxide released during photosynthetic oxygen evolution is also 1:1, has excellent applicability and objectivity, which can logically and reasonably explain the precise coordination between light and dark reactions during photosynthesis, the bicarbonate effect, the Dole effect, the Kok cycle and the neutrality of water and carbon in *** is of great significance for constructing the bionic artificial photosynthetic reactors and scientifically answering the question of the source of elemental stoichiometric relationships in nature.

关键词： Bicarbonate effect Dole effect Kok cycle Heavy oxygen isotope Artificial photosynthetic reactor

Age and fluid source constraints of the Haoyaoerhudong orogenic gold deposit,North China:Evidence from geochronology and noble gas isotopes

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2024年第4期15卷 176-195页

作者： Chenglong Fan Jingwen Mao Huishou Ye Yitian Wang Junchen Liu Wei Jian Xuyang Meng Wenhao Tang Weiwei Chao Peng Wang School of Earth Sciences and Resources China University of GeosciencesBeijing 100083China MNR Key laboratory for Exploration Theory&Technology of Critical Mineral Resources China University of GeosciencesBeijing 100083China Ministry of Natural Resources(MNR)Key laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China Collaborative Innovation Center for Exploration of Nonferrous Metal Deposits and Efficient Utilization of Resources by the Province and Ministry Guilin University of TechnologyGuilin 541004China State Key laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013JiangxiChina School of Earth Sciences and Spatial Information Engineering Hunan University of Science and TechnologyXiangtan 411201China

The Haoyaoerhudong gold deposit,located in the northwestern part of the North China craton(NCC),has produced over 120 metric tonnes(t)of gold since *** has a total reserve of>240 t at average gold grade of 0.62 g/t,making it one of the largest open pit gold mines in *** steeply dipping,large-tonnage,low-grade,vein-or veinlet-type gold orebodies are hosted in strongly-deformed Mesoproterozoic carbonaceous schist of the Bayan Obo *** laminated/boudinaged veins/veinlets in the sinistral ductile-brittle shear zones are dominated by quartz,biotite,gold-bearing löllingite,pyr-rhotite,(arseno)pyrite,with minor native gold,titanite and *** this paper,we present new in situ U-Pb geochronological data on magmatic zircon from the preore dikes,on metamorphic and hydrothermal xenotime,and on hydrothermal titanite from the hydrothermally altered carbonaceous schist and auriferous quartzsulfides veins/veinlets,as well as He-Ar isotopic analysis on gold-bearing(arseno)pyrite in the syn-ore *** metamorphic xenotime U-Pb age of 426±6.0 Ma(2σ)records a regional metamorphic event,possibly related to the accretion of the Bainaimiao arc onto the *** pre-ore andesitic dikes yielded similar emplacement ages at~278 Ma constrained by laser ablation-inductively coupled plasma-mass spectrometry(LA-ICP-MS)U-Pb zircon *** xenotime grains from the altered carbonaceous schist and auriferous quartz-sulfides veins yielded U-Pb ages of 256.0±4.1 Ma(2σ)and 254.4±2.1 Ma(2σ),respectively,overlapping with that of the hydrothermal titanite at 255.4±0.8 Ma(2σ)from the laminated quartz-sulfides *** indicates that the gold mineralization occurred at ca.255 ***~255 Ma gold mineralization age is much younger than the previously reported Early-Middle Permian regional magmatic activity(ca.291 Ma to 268 Ma),and may be associated with the regional sinistral strike-slip event in the late orogenic cycle related to the collision between the Siberian craton

关键词： Xenotime Titanite In situ U-Pb dating Noble gas Orogenic gold deposit North China Craton

Distribution characteristics and indicative significance of grain size and elemental content in surface-sediments of Qinghai Lake， Northeastern Tibetan Plateau

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Earth Science 2024年

作者： Yuqi Cheng Haicheng Wei Ronglei Duan Shun Wang Zhixiang Wang Hongyu Li Fangming Zeng Yilin Hou Hongpan Xue Key laboratory of Green and High-end Utilization of Salt Lake Resources， Qinghai Institute of Salt Lakes， Chinese Academy of Sciences Qinghai Provincial Key laboratory of Geology and Environment of Salt Lakes Qinghai Institute of Salt Lakes， Chinese Academy of Sciences University of Chinese Academy of Sciences

Qinghai Lake in the northeastern Qinghai-Tibet Plateau (QTP)， being sensitive to paleoclimate change and anthropogenic activities， has attracted much attention from paleoenvironmental researchers. Grain size and elemental content in lake sediments are indispensable proxies for reconstructing paleoclimate and paleoenvironment. However， limited research on grain size and elemental content of surface-sediments in Qinghai Lake complicates decoding the information from lacustrine sedimentary strata. In this study， 55 surface-sediment samples were collected for grain size and elemental content analysis， combined with grain size end-member modeling algorithm (EMMA)， correlation (CA) and principal component (PCA) analysis to explore the controlling mechanisms and their environmental indications. Our results show that the hydrodynamic condition controls the distribution of surface-sediments in Qinghai Lake: exhibiting a belt-like pattern of sand-silt-clay， the clockwise circulation in the northwestern and southwestern lake transports sand to the two primary sedimentary centers. Three primary components representing different transport/depositional processes were separated: ‘lacustro-aeolian’， ‘fluvio-aeolian’ and river-transported bedload. Grain size controls the elemental content， particularly in terrestrial particles. Nitrogen (N) and phosphorus (P)， mainly derived from endogenous organic matter (OM)， tend to be absorbed by finer particles. The hydrodynamic conditions and anthropogenic activities also influence their spatial distribution. The chemical weathering index (CIA)， indicating a cold and dry climate， is highly related to grain size. This research provides crucial modern process references for accurately interpreting grain size and element records in sediment cores from Qinghai Lake.

关键词：

Riverine sulfate sources and behaviors in arid environment,Northwest China:Constraints from sulfur and oxygen isotopes

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第3期137卷 716-731页

作者： Yifu Xu Wenjing Liu Bing Xu Zhifang Xu Key laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

The fate of riverine sulfate ion (SO_(4)^(2-)) and its environmental effects in arid environment are difficult to evaluate due to its complicated sources and strongly coupled behaviors with water cycle which is significantly modified by *** understand the sulfur cycle in aquatic systems in arid environment,the chemical and sulfur and oxygen isotopic compositions (δ^(34)S_(SO4)and δ^(18)O_(SO4)) of major rivers around the Badain Jaran Desert,northwestern China,were *** rivers had averaged SO_(4)^(2-)content at 1336μmol/L,over 10times higher than the global *** δ^(34)S_(SO4)and δ^(18)O_(SO4)values ranged from-5.3‰to+11.8‰and+1.6‰to+12.8‰,*** end-member analysis and the inverse model showed that riverine sulfate was mainly derived from evaporites dissolution (0-87%),sulfide oxidation (13%-100%) and precipitation (0-33%),indicating heterogeneity in sulfur sources and behaviors along the river drainage with the lithology variations and climate *** isotopic tools combining with hydro-chemistry compositions could be applied to reveal sulfur cycle in arid *** on the calculation,sulfide oxidation plays the primary role in the headwater and upstream in the Qilian-Mountains area,where sulfide is widely *** the proportion of evaporites dissolution contributing to riverine sulfate is much higher in downstream in a drier ***,less precipitation and higher temperature can lead to more intensive evaporation,affecting the process of sulfide oxidation and enhancing the rates of evaporites dissolution and sulfate precipitation in the basin.

关键词： Sulfur and oxygen isotopes Source apportionment Inverse model Arid environment Inland rivers Northwestern China

Enhancing Geological Understanding and Identifying Gold Anomalies in the Ailaoshan Orogen

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2024年第2期98卷 441-453页

作者： ZHAO Shiyu YANG Lin SONG Yiwei DONG Yuntao FENG Lihao LI Huajian WU Junyu WANG Qingfei State Key laboratory of Geological Processes and Mineral Resources China University of GeosciencesBeijing 100083China Xi’an Center of Mineral Resources Survey China Geological SurveyXi’an 710010China Yunnan Gold Mining Industry Group Kunming 650299China Jiangxi Provincial Key laboratory of Genesis and Prospect for Strategic Minerals East China University of TechnologyNanchang 330013China Frontiers Science Center for Deep-time Digital Earth China University of Geosciences(Beijing)Beijing 100083China

The Ailaoshan Orogen in the southeastern Tibet Plateau,situated between the Yangtze and Simao blocks,underwent a complex structural,magmatic,and metamorphic evolution resulting in different tectonic subzones with varying structural lineaments and elemental *** elements can conceal or reduce anomalies due to the mutual effect between different anomaly *** the whole zone into subzones based on tectonic settings,ore cluster areas,or sample catchment basins(Scb),geochemical and structural anomalies associated with gold(Au)mineralization have been identified utilizing mean plus twice standard deviations(Mean+2STD),factor analysis(FA),concentration-area(CA)modeling of stream sediment geochemical data,and lineament density in both the Ailaoshan Orogen and the individual *** FA in the divided 98 Scbs with 6 Scbs containing Au deposits can roughly ascertain unknown rock types,identify specific element associations of known rocks and discern the porphyry or skarn-type Au *** with methods of Mean+2STD and C-A model of data in the whole orogen,which mistake the anomalies as background or act the background as anomalies,the combined methods of FA and C-A in the separate subzones or Scbs works well in regional metallogenic potential *** of lineament densities with a 10-km circle diameter is not suitable to locate Au deposits because of the delineated large areas of medium-high lineament *** contrast,the use of circle diameters of 1.3 km or 1.7 km in the ore cluster scale delineates areas with a higher concentration of lineament density,consistent with the locations of known Au *** analyzing the map of faults and Au anomalies,two potential prospecting targets,Scbs 1 and 63 with a sandstone as a potential host rock for Au,have been identified in the Ailaoshan *** use of combined methods in the divided subzones proved to be more effective in improving geological understanding and identifying

关键词： minerology geochemistry gold stream sediment sample catchment basin concentration-area model lineament density Ailaoshan Orogen