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Exsolution of ilmenite and Cr-Ti magnetite from olivine of garnet-wehrlite

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Science china Earth Sciences 2005年第9期48卷 1368-1376页

作者： LIU Xiangwen1,2. JIN Zhenmin1,3, QU Jing2.& WANG Lu2.1. State Key Laboratory of Geological Processes and Mineral Resources, china university of geosciences, wuhan 43.074, {2. 2. Graduate school of china university of geosciences, wuhan 43.074, {2. 3. Faculty of Earth Sciences, china university of geosciences, wuhan 43.074, {2. State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Wuhan China Graduate school of china university of geosciences Wuhan China Faculty of Earth Sciences China University of Geosciences Wuhan China

Exsolution of rod-like ilmenite (Ilm) and Cr-Ti magnetite (Mt) have been found in olivine of garnet-wehrlite from the core of Chinese Continental Sciences Drilling (CCSD). Their composition, morphology, crystal structure and their topotaxies with host olivine have been studied in detail by the transmission electron microscopy (TEM) and electron probe microanaly- sis (EPMA) technique. It shows that rod-like Ilm exsolution reported in this paper has similar characteristic with that of Alpe Arami olivine, while Cr-Ti magnetite exsolution mentioned in this paper has large discrepancy with chromite exsolution in Alpe Arami olivine. These observations suggest that both of the exsolutions found in this paper should be solid solution phases in β-olivine at their first period, then experiencing decomposition of solid solution and therefore forming Ilm and Cr-Ti magnetite exsolution with the pressure decreasing. So, this garnet-wehrlite perhaps had been ever located in mantle transition zone with a minimum depth of 300 km.

关键词： garnet-wehrlite, ilmenite, magnetite, exsolution, CCSD.

Variation of karst spring discharge in the recent five decades as an indicator of global climate change: A case study at Shanxi, northern china

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Science china Earth Sciences 2005年第11期48卷 2001-2010页

作者： GUO Qinghai1, WANG Yanxin1, MA Teng1 & LI Luxiu2.1. school of environmental {2., china university of geosciences, wuhan 43.074, china 2. Office of Water Resource Management of Shanxi Province, Taiyuan 030001, china school of environmental {2. China University of Geosciences Wuhan China Office of Water Resource Management of Shanxi Province Taiyuan China

Karst in Shanxi Province is representative of that in northern china, and karst water systems discharge in the form of springs that are among the most important sources for local water supply. Since the 1950s, attenuation has been the major trend of discharge variation of most karst springs at Shanxi. Based on the case study of 7 karst springs including Niangziguan, Xin’an, Guozhuang, Shentou, Jinci, Lancun, and Hongshan springs, the discharge variation process of karst springs was divided into natural fluctuation phase and anthropogenic impact phase. Discharge attenuation of the 7 karst springs was controlled mainly by climate and human activities, with their contributions being respectively about 60% and 40%. According to the dif-ference of the effect of climate and human activities for each spring, attenuation modes of spring discharge fall into three types: natural process dominated attenuation type, exploitation induced process dominated attenuation type, and mixed attenuation type. The total restored discharge variation of 7 karst springs matched well with the global air temperature change in 1956―2.00, clearly indicating the trend of global warming and aridity in the last several decades, and the analysis of discharge variation processes of karst springs can be used as a new tool for global change studies.

关键词： karst, Shanxi, spring discharge, attenuation, climate, human activity, global change

A Technique for Carbon and Chlorine Isotope Analyses of Chlorinated Aliphatic Hydrocarbons in Groundwater

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Journal of Earth Science 2013年第2期24卷 274-281页

作者：甘义群余婷婷周爱国刘运德刘存富 school of environmental {2. China University of Geosciences State Key Laboratory of Biogeology and environmental Geology China University of Geosciences

Chlorinated aliphatic hydrocarbons （CAHs）, significant contaminants in groundwater, can be characterized by stable isotopic compositions of carbon and chlorine. Previously published methods were of low analytical sensitivity or not ideal for natural samples with low concentrations of CAHs. This method is reported here to carry out simultaneously carbon and chlorine isotope analyses for mieromolar concentrations of dissolved CAHs. It was executed by extracting and converting CAHs to carbon dioxide and methyl chloride （CH3CI）. Specially, a continuous-flow interface GasBench Ⅱ was used to extract CH3CI for online chlorine isotope analysis. As a result, it greatly enhances the efficiency for isotope analysis by eliminating procedures for offline CH3CI preparation and separation. Sample size requirement was reduced to approximately 11 pmol chlorine. The standard deviation of δ^＋3C and δ^37CI for both TCE solvents and water samples was better than 0.30‰ and 0.2.%0 （1σ）, *** and chlorine isotope analyses can be used as an important tool to study the sources of organic contaminants in groundwater and their behaviors in the aquifers. The method is applicable to manufacturers＇ products as well as a sample from a polluted site in principle, which will be validated in our field studies.

关键词： chlorine isotope carbon isotope chlorinated aliphatic hydrocarbon (CAH) groundwater organic contamination.

Evolutionary patterns of Productida (Brachiopoda) morphology during the Permian in South china

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Science china Earth Sciences 2008年第11期51卷 1589-1600页

作者： ZHANG Yang1 & HE WeiHong1,2.1 Faculty of Earth Sciences, china university of geosciences, wuhan 43.074, {2. 2.Key Laboratory of Biogeology and environmental Geology of Ministry of Education, china university of geosciences, wuhan 43.074, {2. Faculty of Earth Sciences China University of Geosciences Wuhan China Key Laboratory of Biogeology and environmental Geology of Ministry of Education China University of Geosciences Wuhan China

The evolutionary patterns of Productida (brachiopod) morphology throughout the Permian show that while the percentage proportion of Productida (brachiopod) with strongly concentric and radial ornamentation declined from the Cisuralian to the Guadalupian, and then increased towards the Changhsingian via Wuchiapingian, the percentage proportion of Productida (brachiopod) with fine concentric and radial ornamentation distinctly increased from the Cisuralian to the Guadalupian, slightly declined towards the Wuchiapingian, and then increased towards the Changhsingian. From the Cisuralian to the Changhsingian, the percentage proportion of brachiopods with spinose ornamentation shows a persistent declining trend. The shell size generally indicates a miniaturization trend at species level during the Wuchiapingian to Changhsingian (including the transitional bed). These evolutionary patterns of brachiopod ornamentation and size are possibly related to the anoxia, food shortage, sea-level fluctuation, and change of substrate in the Permian (including the Permian-Triassic transitional interval) in South china.

关键词： brachiopod ornamentation size Permian South china

Improved Approaches Coupling the Method on Discharge Allocation and“High Kv in Wellblock”for Simulating Multiaquifer Wells

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地学前缘 2009年第S1期16卷 23-24页

作者： Quanrong Wang~1,Zhonghua Tang~1,Lijuan Zhai~2.1.school of environmental {2.,china university of geosciences(wuhan),wuhan 43.074,china. 2.school of Foreign Language,china university of geosciences(wuhan),wuhan 43.074,china

The mathematic models to simulate the multiaquifer well using the discharge allocation based on explicit transmissivity-weighted or the implicit transmissivity and the hydraulic gradient(TJ method),can not describe the actual well,especially with vertical flow along the *** order to improve the accuracy of the results,two improved approaches are established,by coupling the ideas of"High Kv in Wellblock"into the aforementioned methods on discharge allocation to consider the vertical flow

关键词： multiaquifer wells discharge allocation high conductivity

Approach to the Relation of Mutual-Feed Joint-Variation in Groundwater Management Model

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Journal of Earth Science 2012年第3期23卷 349-358页

作者：李平卢文喜靳孟贵杨青春 College of Chemistry and Materials South-Central University for Nationalities school of environmental {2. China University of Geosciences College of Environment and Resources Jilin University

In groundwater management,the exchanges between groundwater and other water such as surface water and spring water need to be *** exchange is dependent on the ground-water level,which is called *** pumping rate,groundwater level,and covariate interact and the relation of mutual-feed joint-variation is used to describe their *** article presents a new approach of dealing with the relation in groundwater management *** mathematical for-mulation of the relation,as an additional equality constraint in the optimization model,is developed using response matrix *** the groundwater management model with covariate is set *** code for the simulation and management of groundwater system with covariate is programmed with Fortran 90,and the optimal pumping rate,groundwater level,and covariate are *** approach is verified with a hypothetical ***,the approach is applied to the groundwater management of Qianguo（前郭） area in western Jilin（吉林） *** results indicate that the ap-proach is *** provides a universal solution for various covariates and reduces the computational complexity compared to iteration *** approach is proven to be very efficient to solve ground-water management problem with covariate.

关键词： covariate relation of mutual-feed joint-variation groundwater management response matrix

Electron microscopy study of the sakhaite from endogenous borate deposit in Hunan, china

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Science china Earth Sciences 2004年第3期47卷 232-238页

作者： LIU Xiangwen1,2. YANG Guangming2. ZOU Huamin3, QU Jing1 & ZHAO Wenxia4 1. Graduate school, china university of geosciences, {2., china 2. Test Center, china university of geosciences, {2., china 3. Physics and Technology College, wuhan university, wuhan 430072. china 4. Test Center, Zhongshan university, Guangzhou 5102.5, china Graduate school China University of Geosciences Wuhan 430074 China Test Center China University of Geosciences Wuhan 430074 China Physics and Technology College Wuhan University Wuhan 430072 China Test Center Zhongshan University Guangzhou 510275 China

Sakhaite specimens from an endogenous borate deposit in Hunan Province, china have been studied in detail by means of transmission electron microscopy (TEM). The selected area electron diffraction (SAED) patterns obtained with different crystal zone axes show that the crystal system is cubic, with a = 1.463 nm. The convergent beam electron diffraction (CBED) patterns indicate that the point group and space group of sakhaite is m3m and Fd3m, respec-tively. The space group of synthetic sakhaite determined by Chichagov (1974) is F4132. The possible reasons why the space groups of the natural and the synthetic sakhaites are different are discussed.

关键词： sakhaite, space group, convergent beam electron diffraction (CBED).

Arsenic Biomobilization from Aquifer Sediments by Indigenous Bacteria at Datong Basin and Hetao Plain,Northern china

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地学前缘 2009年第S1期16卷 4-5页

作者： Zuoming Xie,Yanxin Wang school of environmental {2. & MOE Key Laboratory of Biogeology and environmental Geology,china university of geosciences(wuhan),wuhan 43.074,china.

High arsenic groundwater is widely distributed at Datong Basin and Hetao Plain,northern *** investigate the effects of microbial activities on arsenic mobilization in the two high arsenic regions,the microcosm experiments were performed under various conditions of two bacterial strains(XZM001 and YH001,isolated from the two shallow aquifer sedi-

关键词： biomobilization indigenous bacteria As

Analytical method of Cr stable isotope and its application to water pollution survey

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Chinese Science Bulletin 2010年第7期55卷 664-669页

作者： GAO YongJuan 1,2.3,MA Teng 4,5,LING WenLi 1,2.LIU CunFu 4,5 & LI Li 4,5 1Faculty of Earth Science,china university of geosciences,wuhan 43.074,{2. 2.tate Key Laboratory of Geological Processes and Mineral Resources,china university of geosciences,wuhan 43.074,{2. 3 Graduate school,china university of geosciences,wuhan 43.074,{2. 4 Biogeological and environmental Geology Laboratory of Ministry of Education(china university of geosciences) ,wuhan 43.074,{2. 5 Sino-Hungary Joint Laboratory of environmental Sciences and Health,china university of geosciences,wuhan 43.074,{2. Faculty of Earth Science China University of Geosciences Wuhan China State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Wuhan China Graduate school China University of Geosciences Wuhan China Biogeological and environmental Geology Laboratory of Ministry of Education (china university of geosciences) Wuhan China Sino-Hungary Joint Laboratory of environmental Sciences and Health China University of Geosciences Wuhan China

High Cr(VI) concentration is a potential serious risk to environment and ecologic ***,it is essential to effectively monitor Cr contamination in water systems and scientifically evaluate its evolution trend.A new method of in-situ tracer technique by Cr isotopic analysis for quantitatively estimating Cr-contamination and its regional evolution in natural waters as well as a case application are reported in this *** on documented literatures,an experimental procedure for chemical separation and purification of Cr in water samples and its analytical method for Cr isotopic measurement by thermal ionization mass spectrometry(TIMS) are *** samples collected around a chemical factory in Hubei Province were analyzed by this *** samples showδ53Cr values ranging from-1.7‰to 7.3‰and an elevating trend with an increasing in distance from the sampling site to pollution source.A functional correlation following Rayleigh fractionation law was established between sample'sδ53Cr value and its extent of Cr *** study suggests that Cr isotopic analysis is an effective method to reveal the spatial distribution and its evolution trend of Cr contamination in the regional water *** is thus helpful to assessing the self-purifying ability of local water system according to Cr isotopic fractionation.

关键词：铬(VI) 水污染调查稳定同位素应用同位素分析供水系统演变趋势示踪技术