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Science china Earth Sciences 2006年第10期49卷 1032-1042页

The SHRIMP zircon U-Pb geochronology of three typical samples, including two monzo nitic granites from the Lincang batholith and a rhyolite from the Manghuai Formation are presented in the southern Lancangjiang, western Yunnan Province. The analyses of zircons for the biotite monzonitic granites from the northern (02.X-13.) and southern (2.JH-10) Lincang batholith show the single and tight clusters on the concordia, and yield the weighted mean 2.6Pb/2.8U ages of 2.9.4 ± 3.0 Ma and 2.0.4 ± 3.6 Ma, respectively, representing the crystallized ages of these granites. The zircons for the rhyolitic sample (02.X-95) from the Manghuai Formation give a weighted mean 2.6Pb/2.8U age of 2.1.0 ± 5.0 Ma. These data suggest that the igneous rocks from the Lincang granitic batholith and Manghuai Formation have a similar crystallized age. In combination with other data, it is inferred that both were generated at a narrow age span (~2.0 Ma) and were originated from the postcollisional tectonic regime. An early Proterozoic 2.6Pb/2.8U apparent age of 1977±44 Ma is additionally obtained from one zircon from the biotite monzonitic granite (southern Lincang batholith), indicative of devel- opment of the early Proterozoic Yangtze basement in the region. These precisely geochronological data provide important constraints on better understanding the Paleozoic tectonic evolution of the Tethys, western Yunnan Province.

关键词： SHRIMP zircon U-Pb dating, Middle Triassic, Lincang granitic batholith, Manghuai Formation rhyolite, southern Lancangjiang.

The effects of K^+ growth conditions on the accumulation of cesium by the bacterium Thermus sp. TibetanG6

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Science china(Life Sciences) 2006年第2期49卷 123-129页

作者： WANG Hailei1,2.3. KONG Fanjing1,2.3.& ZHENG Mianping1,2.3.1. R&D Center for Saline Lake and Epithermal Deposits, Chinese Academy of Geological Sciences,{3., china 2. Key Open Laboratory of Saline Lake Resources and Environment, Chinese Academy of Geological Sciences,{3., china 3. Institute of Mineral Resources, Chinese Academy of Geological Sciences,{3., china R&D Center for Saline Lake Epithermal Deposits Chinese Academy of Geological Sciences Beijing 100037 China Key Open Laboratory of Saline Lake Resources Environment Chinese Academy of Geological Sciences Beijing 100037 China Institute of Mineral Resources Chinese Academy of Geological Sciences Beijing 100037 China

The accumulation of cesium by the bacterium Thermus sp. TibetanG6 was examined under different K+ growth conditions. The effects of external pH and Na+ on the accumulation of ce-sium were also studied, and the mechanism involved was discussed. K+ regimes played an important role in the accumulation of cesium by the strain TibetanG6. The quantity of cesium accumulated (2. h) was much higher in K+-deficient regime than that in K+-sufficient regime. The pH and Na+ had different effects on the accumulation of cesium in the two K+ regimes. IR spectra analyses indicated that the biosorption is a process of homeostasis with cesium initially accumulated on the cell wall.

关键词： Thermus sp. TibetanG6, cesium, bioaccumulation, K+-growth condition, pH, sodium, IR spectroscopy.

Mesozoic-Cenozoic tectonic transition in Kuqa Depression-Tianshan,Northwest china:Evidence from sandstone detrital and geochemical records

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Science china Earth Sciences 2005年第9期48卷 1387-1402页

作者： LI Zhong1, GUO Hong2. WANG Daoxuan3.& LIN Wei1 1. Institute of Geology and Geophysics, Chinese Academy of Sciences, beijing 10002.,{3. 2. Tarim Oilfield Branch, CNPC, Korla 841000,{3. 3. Hefei University of Industry, Tunxilu 193. Hefei 2.0009,{3. 1. Institute of Geology and Geophysics Chinese Academy of Sciences 100029 Beijing Chin 2. Tarim Oilfield Branch CNPC 841000 Korla China 3. Hefei University of Industry Tunxilu 193 230009 Hefei Chin

Similar to compositional evolution of sandstone modes and detrital heavy minerals from different profiles in the Kuqa Depression, Northwest china, major element analysis of whole sandstones from the same profiles shows four discontinuous depositional interfaces or periods, respectively corresponding to Lower Triassic\Middle Triassic, Upper Jurassic\Lower Cretaceous, Lower Cretaceous\Paleogene and Miocene\Pliocene, and indicates five-phase evolution during Mesozoic-Cenozoic: (1) From the first to fifth phase, a depositional suite changes from maroon and coarse clastic, through grey-dark grey and fine, red and coarse, red-mottled, interlayered by gypsum, to brown and coarse clastic assemblages, accompanying detrital component evolution in unstable-stable-unstable-very unstable-very unstable assem- blages. It is indicated that carbonate and complex detritus gradually dominate in sandstones in post-Late Jurassic, with rapid reduction of compositional maturity. (2. For major element geo- chemical parameters of whole sandstones, CaO and Fe2.O * 3.MgO contents show a change sequence in high-low-high-higher-highest values, with rapid increasing in post-Late Jurassic. (3. Contra some aggregative indicators for weathering indexes of sandstone detrital component, Al2.3.(CaO+Na2.) and ln(Q/(L+CE)), show a change sequence in low-high-low-lower-lowest ratios, with rapid decreasing in post-Late Jurassic. It is found that sandstone samples of the first, second and later three phases may be distinguished from the A-CN-K and A-CNK-FM diagrams respectively. Therefore, in the Kuqa Depression-Tianshan, the most important discontinuous depositional interface recording paleotectonic and paleoclimatic transition occurred in Early Triassic\Middle Triassic and Late Jurassic\Early Cretaceous, respectively, and, however, tec- tonic differentiations of basin-range system finally result in distinct depositional systems but similar detrital weathering indexes across the Lower Cretaceous\Paleogene

关键词： Tianshan, Kuqa Depression, basin-range, depositional record, tectonic transition, Mesozoic-Cenozoic.

Spectral analysis of quasi-stationary sea surface topography from GRACE mission

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Science china Earth Sciences 2005年第11期48卷 2040-2048页

作者： ZHANG Zizhan1,2.& LU Yang1,3.1. Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 43.077, china 2. Graduate School of the Chinese Academy of Sciences,{3., china 3. Unite Center for Astro-geodymics Research, Chinese Academy of Sciences, Shanghai 2.003., china 1. Institute of Geodesy and Geophysics Chinese Academy of Sciences 430077 Wuhan China 2. Graduate School of the Chinese Academy of Sciences 100039 Beijing China 3. Unite Center for Astro-geodymics Research Chinese Academy of Sciences 200030 Shanghai China

During the last two decades satellite altimetry has offered an abundance of meas-urements of the sea surface resulting in the improvement of global mean sea surface height (MSSH) and marine geoid determination. On the other hand, with the launching of new genera-tion gravity satellites, some high accuracy long-wavelength gravity models are available. These breakthroughs give us a great opportunity for new estimation of quasi-stationary sea surface topography (QSST). In this paper, the new gravity model GGM01C derived from GRACE mission is briefly presented, and a new global high precision and high-resolution QSST is determined based on the GGM01C model and the global MSSH. The spectral features of the QSST esti-mated by GGM01C and EGM96 gravity model to degree/order 2.0 are discussed by spectral analysis. As a result, the QSST is mainly composed of long waves, medium waves partially and short waves scarcely, its power spectral structures are different between the zonal direction and the meridional direction, there are great differences between the two models, which maybe ex-plain why the ocean currents derived from the two gravity models by Tapley show different pat-terns.

关键词： quasi-stationary sea surface topography, mean sea surface height, GGM01, fast Fourier transform, spectral analysis

Approximation of dense-n/2.subgraph and table compression problems

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Science china Mathematics 2005年第9期48卷 1223-1233页

作者： XU Dachuan~1 HAN Jiye~2.& DU Dongle~3.1. College of Applied Sciences,beijing University of Technology,beijing 10002.,{2. 2. Institute of Applied Mathematics,Academy of Mathematics and Systems Science,Chinese Academy of Sciences,beijing 100080,{2. 3. Faculty of Administration,University of New Brunswick,P.O.Box 4400,Fredericton,NB E3. 5A3.Canada College of Applied Sciences Beijing University of Technology Beijing 100022 China Institute of Applied Mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China Faculty of Administration University of New Brunswick P.O. Box 4400 Fredericton NB E3B 5A3 Canada

We develop improved approximation algorithms for two NP-hard problems: the dense-n/2.subgraph and table *** on SDP relaxation and advanced rounding techniques,we first propose 0. 5982.and 0. 5970-approximation algorithms respec- tively for the dense-n/2.subgraph problem (DSP) and the table compression problem (TCP). Then we improve these bounds to 0. 62.3.and 0. 6708 respectively for DSP and TCP by adding triangle inequalities to strengthen the SDP *** results for TCP beat the 0. 5 bound of a simple greedy algorithm on this problem,and hence answer an open question of Anderson in an affirmative way.

关键词： dense-n/2.subgraph problem(DSP) table compression problem(TCP) SDP approximation ratio

Discovery of Cu-Zn,Cu-Sn intermetallic minerals and its significance for genesis of the Mianning-Dechang REE Metallogenic Belt,Sichuan Province,china

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Science china Earth Sciences 2006年第6期49卷 597-603页

作者： XIE Yuling1, HOU Zengqian2. XU Jiuhua1, YUAN Zhongxin2. BAI Ge2.& LI Xiaoyu3.1. Civil and Environmental Engineering School, University of Science and Technology {3., {3. 100083.{2. 2. Institute of Geology, Chinese Academy of Geological Sciences, beijing 10003.,{2. 3. The 109th Geological Team, Sichuan Bureau of Mineral Exploration, Chengdu 610100,{2. 1. Civil and Environmental Engineering School University of Science and Technology Beijing Beijing 100083 China 2. Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China 3. The 109th Geological Team Sichuan Bureau of Mineral Exploration Chengdu 610100 China

Mianning-Dechang Himalayan REE Metallogenetic Belt in Sichuan Province lies along the western margin of the Yangtze Craton. We have conducted detailed mineralogical studies on ore minerals collected from Maoniuping and Dalucao, the two largest deposits in the belt. With optical microscope, SEM/EDS, and EPMA, three rare intermetallic minerals, i.e., zinccopperite (Cu2.n), Sn- bearing native copper, and Cu-bearing jupiter were found to occur in the main ore along with barite, fluorite, apatite, sulfide and bastnaesite. Since the conditions under which zinccopperite and Sn- bearing native copper formed are quite unique, finding of these minerals, for the first time in domestic REE deposits, has significant implications for the genesis of the ore deposits in which they occur. In comparison with Cu-Zn intermetallic minerals in other occurrences, we propose that the formation of this REE metallogenetic belt is associated with fast upwelling of the Himalayan magma from deep source.

关键词： Mianning-Dechang REE metallogenetic belt, Cu-bearing intermetallic minerals, EPMA, genesis significance, deep source magmatic activity.

Re-Os(ICP-MS)dating of the massive sulfide ores from the Jinchuan Ni-Cu-PGE deposit

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Science china Earth Sciences 2005年第10期48卷 1672-1677页

作者： YANG Gang1,2. DU Andao1, LU Jiren3. QU Wenjun1 & CHEN Jiangfeng2.1. National Research Center of Geoanalysis, beijing 10003.,{3. 2. Laboratory for Earth Material Cycling, School of Earth and Space Sciences, University of Science and Technology of{3., Hefei 2.002.,{3. 3. Institute of Mineral Resource, Chinese Academy of Geological Sciences, beijing 10003.,{3. National Research Center of Geoanalysis beijing china Laboratory for Earth Material Cycling School of Earth and Space Sciences University of Science and Technology of China Hefei China Institute of Mineral Resource Chinese Academy of Geological Sciences beijing china

Massive sulfide ore from the Jinchuan Ni-Cu-PGE deposit was dated by Re-Os technique using Carius Tube digestion, Os distillation, Re extraction by acetone and ICP-MS measurement. An isochron giving an age of 83. ± 3. Ma, initial 187Os/188Os ratio of 0.2.9 ± 0.018 (MSWD = 1.7) and γOs = 13. ± 15 is obtained. The Re-Os age obtained agrees, within analytical uncertainties, with previous SHRIMP zircon U-Pb age of 82. ± 8 Ma (n=5, MSWD = 4.3.. The result suggests that the deposit was formed at Neoproterozoic and that the formation of the Jinchuan Ni-Cu-PGE sulfide deposit may be closely related to the plume activity, which were attributed to the breakup of the Rodinia supercontinent. The high γOs of the massive ores sug-gests that crustal material was involved in the formation of the Jinchuan deposit, however, the quantity of the added crustal material is less than 10%.

关键词： Jinchuan Ni-Cu-PGE deposit, Re-Os dating, ICP-MS.

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

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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 Center 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@***) 1. Department of Physics College of Science Beijing Jiaotong University 100044 Beijing China 2. Laboratory of Optical Physics Institute of Physics and Center for Condensed Matter Physics Chinese Academy of Sciences 100080 Beijing China 3. General Research Institute for Nonferrous Metals 100088 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.

Environmental characteristics of Mid-Holocene recorded by lacustrine sediments from Lake Daihai, north environment sensitive zone, china

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Science china Earth Sciences 2006年第9期49卷 968-981页

作者： SUN Qianli1,2. ZHOU Jie1, SHEN Ji3. CHEN Peng1,2. WU Feng1,2.& XIE Xiuping1,2.1. State Key Lab of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075, china 2. Graduate University of Chinese Academy of Sciences, beijing 10003., china 3. Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 2.0008, china 1. State Key Lab of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an 710075 China 2. Graduate University of Chinese Academy of Sciences Beijing 100039 China 3. Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China

Climate proxies, such as total organic carbon and nitrogen (TOC, TN), carbonate content (CaCO3., grain-size and pollen of the sediment core retrieved from enclosed Lake Daihai which lies in the north china environment sensitive zone are analyzed to reconstruct the environment evolution of the area based on high-resolution radiocarbon chronology. The results reveal that the TOC and TN contents of the sediments correlate well with pollen percentage and pollen flux variations during the Holocene, and both reach their peak values simultaneously at 6.7―3.5 ka BP (calendar age, 7.6―3.6 ka BP). Since 6.7 ka BP, both the CaCO3.and organic matter contents of the core have simultaneous variations, and their high values also occur during 6.7―3.5 ka BP. While during 9.0―6.7 ka BP (calendar age, 10―7.6 ka BP) relatively lower level of organic matter content and pollen flux corre- spond to the higher level of carbonate content. The above relations suggest that during 6.7―3.5 ka BP, the productivity and effective precipitation were greatly improved in the lake drainage area, and this would probably strengthen the hydrodynamic conditions, enhancing organic matter, pollen and carbonate inputs from terrestrial sources. Such processes would account for the enrichment of both organic matter and carbonate in the sediments. While during 9.0―6.7 ka BP, the lower level of or- ganic matter, pollen flux but high carbonate content show depressed productivity and declined vege- tation coverage. The higher carbonate content at this stage would have probably resulted from the higher evaporation ratio of the lake water under relatively drier climate conditions. Therefore, it is in- ferred that during 6.7―3.5 ka BP, the climate was more humid with abundant rainfalls and vegetation was more flourishing in the Lake Daihai area. This can be seen as Holocene Climate Optimum (HCO). As a result, this has evident discrepancies with the traditional notion that the HCO occurs at Early Holocene or early Mid

关键词： Lake Daihai, Mid-Holocene, lacustrine sediments, environmental characteristics.

Theoretical study on the reaction mechanism of(CH_3._3.O+CO

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Science china Chemistry 2005年第1期48卷 18-24页

作者： ZHAO Hongmei1,2.3. SUN Chengke1,4, ZHANG Rongchang3. XI Hongmin3.& LI Zonghe1 1. Department of Chemistry, beijing Normal University, beijing 100875,{2. 2. The Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, beijing 100080,{2. 3. Department of Chemistry, Beihua University, Jilin 13.0}13.{2. 4. Department of Chemistry, Qujing Normal University, Yunnan 655000,{2. 1. Department of Chemistry Beijing Normal University 100875 Beijing China 2. The Laboratory of Molecular Reaction Dynamics Institute of Chemistry Chinese Academy of Sciences 100080 Beijing China 3. Department of Chemistry Beihua University 132013 Jilin China 4. Department of Chemistry Qujing Normal University 655000 Yunnan China

The reaction mechanism of (CH3.3.O with CO has been theoretically investigated using density-functional theory (DFT) calculations at B3.YP/6-3.G* level. In order to get more reliable energy values the single-point energy is evaluated at CCSD (T)/6-3.++G** level. The results show that the reaction is multi-channel and the reaction of (CH3.3.O radical with CO mostly produces (CH3.3. + CO2. The reaction could play a role in eliminating air pollution.

关键词： DFT, B3.YP, (CH3.3.O, radical.