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chinese Science Bulletin 2002年第13期47卷 1119-1124页

作者： chu xuelei, sun min & zhou meifuinstitute of geology and geophysics, chinese academy of sciences, beijing 1.0029, China Key Laboratory of mineral Resources, Institute of {5. and {5., chinese academy of sciences, beijing 100101, China Department Institute of geology and geophysics Chinese Academy of Sciences Beijing China Key Laboratory of mineral Resources Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China Department of Earth sciences The University of Hong Kong Hong Kong China

By comparing PGE patterns of sulfide ores with that of basic-ultrabasic dikes occurring in the Dajing Cu-polymetallic deposit, we discover that there are similar positive slopes between the basic-ultrabasic dikes and the black ores composed mainly of sphalerite and galena, reflecting affinity of their source. The PGE patterns of the yellow ores composed basically of chalcopyrite, arsenopyrite and pyrite are actually different. One is close to the pattern of the mantle 1herzolite, and others resemble the pattern of the basic rocks. However, the concentrations of Ru are higher in the yellow ores, reflecting that sulfur attains or approaches saturation in their parent magma. The PGE characteristics of ores and dikes show that the magmas derived from the deep of crust and the metallogenic elements were supplied mainly by growth material of the crust. In addition, the mantle-derived magma also offered some elements.

关键词： Da Hinggan area polymetallic deposit PGE pattern hypomagma.

^(207)Pb/^(206)Pb determination of zircons by laser probe-inductively coupled plasma mass spectrometry

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chinese Science Bulletin 1998年第23期43卷 2008-2012页

作者： YAN Xin\+1, chu Zhuyin\+1, sun min\+2, XU Ping\+1 and zhou Xinhua\+11. Institute of geology,{5., beijing 1.0029, China 2. Department of Geosciences, Hong Kong University, Hong Kong, China Institute of geology Chinese Academy of Sciences Beijing China Department of Geosciences Hong Kong University Hong Kong China

Laser probe_inductively coupled plasma mass spectrometry (LP_ICP_MS) was used to determine 207 Pb/ 206 Pb ratios in single zircon grains. A Nd∶YAG laser operating at 1 064 nm and a Fisons_VG PQII Turbo ICP_MS were employed. For the known zircons, the 207 Pb/ 206 Pb results of LP_ICP_MS are close to the thermal ionization mass spectrometry (TIMS) results. The spatial resolution of this method is 40-5. μm and the sensitivities for lead isotopes are about 300-400 cps/ppm. The precision of 207 Pb/ 206 Pb ratio is 0.3%-4% and depends on the lead concentration of the sampling pits. LP_ICP_MS provides a simple, rapid and economic method for zircon 207 Pb/ 206 Pb determination.

关键词： laser probe_inductively coupled plasma mass spectrometry zircon microanalysis.

Embryonic stem cells generated by nuclear transfer of human somatic nuclei into rabbit oocytes

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Cell Research 2003年第4期13卷 251-263页

作者： YING CHEN, ZHI Xu HE, AILIAN LIU, KAI WANG, WEN WEI MAO, JIAN XIN chu, YONG LU, ZHENG Fu FANG, YING TANG SHI, QING ZHANG YANG, DA YUAN CHEN, min RANG WANG, JIN SONG LI, SHAO LIANG HUANG, XIANG YIN KONG, YAO zhou SHI, Zm QIANG WANG, JIA HuI XIA, ZHI GAO LONG, ZHI GANG XUE, WEN XIANG DING, HuI ZHEN SHENG Center for Developmental Biology, Shanghai Second Medical University, Shanghai 200092, China Laboratory of Stem Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological sciences, chinese academy of sciences, 1665.Kong Jiang Road, Shanghai 200092, China Center for Stem Cell Research, the Second Affiliated Hospital, {5. Yat-Sen University, Guangzhou 5.0120,China State Key Laboratory of Reproductive Biology, Institute of Zoology, chinese academy of sciences, 19 Zhong-guan Cun Road, Haidian District, {5. 100080, China Health Science Center, Shanghai Institutes of Biological sciences, chinese academy of sciences and Shanghai Second Medical University, Shanghai 200025. China National Laboratory of Medical Genetics, Central South University, 88 Xiangya Road, Changsha 410078, China Xinhua Hospital, Shanghai Second Medical University, 1665.Kong Jiang Road, Shanghai 200092, China 2Laboratory of Stem Cell Biology Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences 1665 Kong Jiang Road Shanghai 200092 China. 3Center for Stem Cell Research the Second Affiliated Hospital Sun Yat-Sen University Guangzhou 510120 China. 2Laboratory of Stem Cell Biology Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences 1665 Kong Jiang Road Shanghai 200092 China. 2Laboratory of Stem Cell Biology Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences 1665 Kong Jiang Road Shanghai 200092 China. 2Laboratory of Stem Cell Biology Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences 1665 Kong Jiang Road Shanghai 200092 China. 2Laboratory of Stem Cell Biology Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences 1665 Kong Jiang Road Shanghai 200092 China. 2Laboratory of Stem Cell Biology Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences 1665 Kong Jiang Road Shanghai 200092 China. 2Laboratory of Stem Cell Biology Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences 1665 Kong Jiang Road Shanghai 200092 China. 2Laboratory of Stem Cell Biology Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences 1665 Kong Jiang Road Shanghai 200092 China. 2Laboratory of Stem Cell Biology Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences 1665 Kong Jiang Road Shanghai 200092 China. 4State Key Laboratory of Reproductive Biology Institute of Zoology Chinese Academy of Sciences 19 Zhong-guan Cun Road Haidian District Beijing 10008

To solve the problem of immune incompatibility, nuclear transplantation has been envisaged as a means to produce cells or tissues for human autologous transplantation. Here we have derived embryonic stem cells by the transfer of human somatic nuclei into rabbit oocytes. The number of blastocysts that developed from the fused nuclear transfer was comparable among nuclear donors at ages of 5. 42, 5. and 60 years, and nuclear transfer (NT) embryonic stem cells (ntES cells) were subsequently derived from each of the four age groups. These results suggest that human somatic nuclei can form ntES cells independent of the age of the donor. The derived ntES cells are human based on karyotype, isogenicity, in situ hybridization, PCR and immunocytochemistry with probes that distinguish between the various species. The ntES cells maintain the capability of sustained growth in an undifferentiated state, and form embryoid bodies, which, on further induction, give rise to cell types such as neuron and muscle, as well

关键词： nuclear transfer (NT) somatic cell nuclear transfer (SCNT) embryonic stem cells (ES cell) therapeutic cloning rabbit oocyte.

The discovery of the oldest rocks in the Kuluketage area and its geological implications

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Science China Earth sciences 2011年第3期54卷 342-348页

作者： LONG XiaoPing YUAN Chao sun min XIAO WenJiao ZHAO Guochun zhou KeFa WANG YuJing HU AiQin Key Laboratory of Isotope Geochronology and Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China Department of Earth sciences The University of Hong Kong Pokfulam Road Hong Kong China State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Xinjiang Resources and Environment Center Urumqi 830000 China

The basement rocks in the Kuluketage area are composed predominately of tonalite-trondhjemite-granodiorite rocks, and occured mainly in Xinger and Korla. U-Pb dating of TTG gneiss near Korla yielded a late Neoarchean weighted mean 207Pb/206Pb age of 2.65.Ga, which is the oldest published age for the TTG rocks in the Kuluketage area and thus suggests that Archean terrane in the area was formed in the late Neoarchean. The Korla gneiss is much younger than the TTG rocks in the northern Altyn Tagh, eastern Tarim Craton, indicating that the oldest terrane of the Tarim Craton was exposed probably in the northern Altyn Tagh. Until late Neoarchean, the Tarim continent extends to the Kuluketage area and finally had generated a relatively large uniform Archean basement within the craton. Zircon Hf isotopic analyses of the TTG gneiss give low εHf(t) values (-5.to 1) with Paleoarchean to Mesoarchean two-stage model ages (TDM2) between 3.0 and 3.3 Ga, suggesting that the basement rocks in the northern Tarim Craton were derived dominately from partial melting of Paleoarchean to Mesoarchean juvenile crustal material. The Hf model ages, therefore, indicate that no continent crust older than 3.3 Ga existed in the Kuluketage area.

关键词： Tarim Craton Archean crustal growth zircon dating Hf isotope

High temperatures and high pressures Brillouin scattering studies of liquid H2O+CO2 mixtures

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High temperatures and high pressures Brillouin scattering st...

Variations in melt supply along an orthogonal supersegment of the Southwest Indian Ridge(16°–25.E)

中国科学院地质与地球物理研究所第十届(2010年度)学术年会

作者： Junfeng Qin,~1 min Li,~2Jun Li,~1Rongyan Chen,~2Zhenhao Duan,~1Qiang zhou,~2 Fangfei Li,~(2,a))and Qiliang Cui~2 1 Key Laboratory of Earth’s Deep Interior,Institute of geology and geophysics,chinese {5. of {5.,beijing 10029,China 2 State Key Lab of Superhard Materials,Jilin University,Changchun 130012,China

The Brillouin scattering spectroscopy studies have been conducted in a diamond anvil cell for a liquid mixtures composed of 95.mol%HO and 5.mol%CO under high temperatures and *** sound velocity,refractive index,density,and adiabatic bulk modulus of the HO + CO mixtures were determined under pressures up to the freezing point at 293,45.,and 5.5.K. It is found from the experiment that sound velocities of the liquid mixture are substantially lower than those of pure water at 5.5.K,but not at lower *** presented an empirical relation of the density in terms of pressure and *** results show that liquid HO+CO mixtures are more compressible than water obtained from an existing equation of state of at 45. and 5.5.K.

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Acta Oceanologica Sinica 2021年第5期40卷 94-104页

作者： Caicai Zha Jian Lin Zhiyuan zhou Xubo Zhang min Xu Fan Zhang Key Laboratory of Ocean and Marginal Sea geology South China Sea Institute of OceanologyInnovation Academy of South China Sea Ecology and Environmental EngineeringChinese Academy of SciencesGuangzhou 510301China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China China-Pakistan Joint Research Center on Earth sciences CAS-HECIslamabad 45320Pakistan Department of geology and geophysics Woods Hole Oceanographic InstitutionWoods HoleMA 02543USA University of chinese academy of sciences Beijing 100049China Department of Ocean Science and Engineering Southern University of Science and TechnologyShenzhen 518055China

The orthogonal supersegment of the ultraslow-spreading Southwest Indian Ridge at 16°–25.E is characterized by significant along-axis variations of mantle potential temperature.A detailed analysis of multibeam bathymetry,gravity,and magnetic data were performed to investigate its variations in magma supply and crustal accretion *** results revealed distinct across-axis variations of magma ***,the regionally averaged crustal thickness reduced systematically from around 7 Ma to the present,indicating a regionally decreasing magma *** crustal structure is asymmetric in regional scale between the conjugate ridge flanks,with the faster-spreading southern flank showing thinner crust and greater degree of tectonic *** models of mantle melting suggested that the observed variations in axial crustal thickness and major element geochemistry can be adequately explained by an eastward decrease in mantle potential temperature of about40℃ beneath the ridge *** this work,a synthesized model was proposed to explain the axial variations of magma supply and ridge segmentation *** existence of large ridge-axis offsets may play important roles in controlling melt *** large ridge-axis offsets in the eastern section(21°–25.E)caused sustained along-axis focusing of magma supply at the centers of eastern ridge segments,enabling quasi-stable *** contrast,the western section(16°–21°E),which lacks large ridge-axis offsets,is associated with unstable segmentation patterns.

关键词： ultraslow-spreading ridge Southwest Indian Ridge ridge segmentation asymmetric accretion melt supply mantle temperature gradient

mineral and Bone Disorder and Its Association with Cardiovascular Parameters in chinese Patients with Chronic Kidney Disease

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chinese Medical Journal 2016年第19期129卷 2275-2280页

作者： chu zhou Fang Wang Jin-Wei Wang Lu-Xia Zhang ming-Hui Zhao Renal Division Department of Medicine Peking University First Hospital Peking University Institute of Nephrology Key Laboratory of Renal DiseaseMinistry of Health of China Key Laboratory of ChronicKidney Disease Prevention and Treatment (Peking University) Ministry of Education Beijing 100034 China Guizhou Medical University Guiyang Guizhou 550004 China

Background：mineral and bone disorder （MBD）,especially hyperphosphatemia,is an independently risk factor for adverse prognosis in patients with chronic kidney disease （CKD）.However,CKD-MBD among chinese population was poorly *** study aimed to investigate the status of MBD and its association with cardiovascular parameters in chinese patients with predialysis ***：chinese Cohort Study of Chronic Kidney Disease （C-STRIDE） is a prospective multicenter cohort study involving predialysis CKD patients in *** of MBD,including serum phosphorus,calcium,and intact parathyroid hormone,were measured in baseline samples at the patients＆#39; *** association between serum phosphorus and abdominal aortic calcification （AAC）,left ventricular hypertrophy （LVH） were examined by logistic regression ***：Altogether 3194 predialysis patients with mean estimated glomerular filtration of 5..8 ± 33.1 ml·min^- 1· 1.73 m^- 2 were *** proportion of patients with hyperphosphatemia were 2.6%,2.9%,6.8%,and 27.1% in CKD Stages 3a,3b,4,and 5.***,71.6% of the patients with hyperphosphatemia did not receive any phosphate-binder （PB）.Lateral abdominal X-rays were obtained in 2280 patients,9.8% of the patients were diagnosed as having *** 2219 patients had data of echocardiography,and 13.2% of them were diagnosed with *** logistic regression analysis showed that serum phosphorus was independently associated with the presence of AAC and ***：In chinese patients with CKD,the percentage of hyperphosphatemia is comparable to that of other countries while the usage of PBs is *** prevalence of vascular calcification in chinese patients is relatively lower compared with the Caucasian population.

关键词： Chronic Kidney Disease Hyperphosphatemia Left Ventricular Hypertrophy mineral and Bone Disorder Vascular Calcification

CEPC Technical Design Report

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Radiation Detection Technology and Methods 2024年第1期8卷 I0003-I0016,1-1091页

作者： Waleed Abdallah Tiago Carlos Adorno de Freitas Konstantin Afanaciev Shakeel Ahmad Ijaz Ahmed Xiaocong Ai Abid Aleem Wolfgang Altmannshofer Fabio Alves Weiming An Rui An Daniele Paolo Anderle Stefan Antusch Yasuo Arai Andrej Arbuzov Abdesslam Arhrib Mustafa Ashry Sha Bai Yu Bai Yang Bai Vipul Bairathi Csaba Balazs Philip Bambade Yong Ban Tripamo Bandyopadhyay Shou-Shan Bao Desmond P.Barber Ayse Bat Varvara Batozskaya Subash Chandra Behera Alexander Belyaev Michele Bertucci Xiao-Jun Bi Yuanjie Bi Tianjian Bian Fabrizio Bianchi Thomas Biekotter Michela Biglietti Shalva Bilanishvili Deng Binglin Denis Bodrov Anton Bogomyagkov Serge Bondarenko Stewart Boogert Maarten Boonekamp Marcello Borri Angelo Bosotti Vincent Boudry Mohammed Boukidi Igor Boyko Ivanka Bozovic Giuseppe Bozzi Jean-Claude Brient Anastasiia Budzinskaya Masroor Bukhari Vladimir Bytev Giacomo Cacciapaglia Hua Cai Wenyong Cai Wujun Cai Yijian Cai Yizhou Cai Yuchen Cai Haiying Cai Huacheng Cai Lorenzo Calibbi Junsong Cang Guofu Cao Jianshe Cao Antoine Chance Xuejun Chang Yue Chang Zhe Chang Xinyuan Chang Wei Chao Auttakit Chatrabhuti Yimin Che Yuzhi Che Bin Chen Danping Chen Fuqing Chen Fusan Chen Gang Chen Guoming Chen Hua-Xing Chen Huirun Chen Jinhui Chen Ji-Yuan Chen Kai Chen Mali Chen mingjun Chen mingshui Chen Ning Chen Shanhong Chen Shanzhen Chen Shao-Long Chen Shaomin Chen Shiqiang Chen Tianlu Chen Wei Chen Xiang Chen Xiaoyu Chen Xin Chen Xun Chen Xurong Chen Ye Chen Ying Chen Yukai Chen Zelin Chen Zilin Chen Gang Chen Boping Chen chunhui Chen Hok chuen Cheng Huajie Cheng Shan Cheng Tongguang Cheng Yunlong Chi Pietro Chimenti Wen Han Chiu Guk Cho ming-chung chu Xiaotong chu Ziliang chu Guglielmo Coloretti Andreas Crivellin Hanhua Cui Xiaohao Cui Zhaoyuan Cui Brunella D'Anzi Ling-Yun Dai Xinchen Dai Xuwen Dai Antonio De Maria Nicola De Filippis Christophe De La Taille Francesca De Mori Chiara De Sio Elisa Del Core Shuangxue Deng Wei-Tian Deng Zhi Deng Ziyan Deng Bhupal Dev Tang Dewen Biagio Di Micco Ran Ding Siqin Dingl Yadong Ding Haiyi Dong Jianin AGH University of Science and Technology Faculty of Physics and Applied Computer ScienceKrakow Anhui University HefeiAnhui Applied Physics Department Federal Urdu University of ArtsScience and TechnologyIslamabad Banaras Hindu University Institute of ScienceVaranasi Bandirma Onyedi Eylul University Bandirma Beihang University Beijing beijing Computational Science Research Center Beijing beijing Conveyi LTD Beijing beijing Glass Research Institute Co. LtdBeijing beijing Institute of Technology Beijing beijing Normal University Beijing Brown University ProvidenceRI Budker Institute of Nuclear Physics Novosibirsk Cadi Ayyad University Laboratory of Fundamental and Applied PhysicsPolydisciplinary FacultyMarrakech Cairo University Giza Center for Theory and Computation National Tsing Hua UniversityHsinchu Central China Normal University WuhanHubei Central South University ChangshaHunan Centro de Fisica Teorica de Particulas Universidade Tecnica de LisboaLisboa Chengdu KaitengSifang Digital Radio&TV Equipment Co. LtdChengduSichuan China academy of engineering physics MianyangSichuan China building materials academy Beijing China Center of Advanced Science and Technology Beijing China Institute of Atomic Energy Beijing China Jiliang University HangzhouZhejiang China Nuclear Instrument CO. LTDBeijing China University of Geosciences Beijing China University of Geosciences WuhanHubei China University of mining and Technology XuzhouJiangsu China West Normal University NanchongSichuan Chongqing University Department of PhysicsChongqing chulalongkorn University Bangkok City University of Hong Kong Department of PhysicsHong Kong Cockcroft Institute Daresbury Cornell University IthacaNY CPPM(AMU/IPhU&CNRS/INP) Marseille Dalian minzu University DalianLiaoning Dalian University of Technology Department of PhysicsDalian Deutsches Elektronen-Synchrotron DESY Hamburg Dzhelepov Laboratory of Nuclear Problems of Joint Institute for Nuclear Research(DLNP JINR) Dubna East China University Of Science And Technol

The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international *** complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs *** its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5.10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs *** the SR power to 5. MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of *** Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015.and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering ***,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection *** is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 *** commencement of experiments and data collection could potentially be initiated in the mid-2030s.

关键词： initiated exceeding precise

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基于高精度重力勘探对地下空洞的探测研究

物探与化探 2024年第3期48卷 876-883页

作者：杨敏徐新强陈明纪晓琳王万银赵东明周巍张义蜜西安测绘总站陕西西安710054 中国地质大学(武汉)地球物理与空间信息学院地球内部多尺度成像湖北省重点实验室湖北武汉430074 信息工程大学地理空间信息学院河南郑州450001 广东省地质物探工程勘察院广东广州510000 空军工程大学信息与导航学院陕西西安710007 长安大学地质工程与测绘学院陕西西安710054 海洋油气勘探国家工程研究中心北京100028 智慧地球重点实验室陕西西安710054

地下空洞埋藏浅、规模小不易探测,随着重力感应技术的发展,给准确快速获取微重力变化为探测地下空洞带来新机会,对小规模地下空洞的探测能力具有广泛的研究和实用价值。本文从重力基础理论、重力探测技术、重力数据处理及反演3方面对地... 详细信息

地下空洞埋藏浅、规模小不易探测,随着重力感应技术的发展,给准确快速获取微重力变化为探测地下空洞带来新机会,对小规模地下空洞的探测能力具有广泛的研究和实用价值。本文从重力基础理论、重力探测技术、重力数据处理及反演3方面对地下空洞进行系统的分析研究。在给定形体大小、重力数据精度的情况下,通过二分法计算出了重力探测的最大埋藏深度;将高密度采集、高精度重力探测方法用于某区客运站地下人行通道实际探测,获得一套高精度重力格网数据,理论研究和实测结果表明,现有重力仪器具有探测地下空洞的能力;采用最小曲率位场分离方法、2.5.人机交互反演和靶区识别三维物性快速反演方法,得到地下人行通道近SN向的分布,埋藏深度大致2.5.5.m,这与实际情况相符。本次研究为地下空洞探测摸索出一套完整的重力勘探流程,具有一定的参考价值。

关键词：重力勘探地下空洞客运站地下人行通道正反演研究

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西安地区全新世气候变化与土壤侵蚀研究

土壤学报 2021年第6期58卷 1404-1415页

作者：周旗赵景波苏敏王晓宁马延东楚纯洁宝鸡文理学院陕西省灾害监测与机理模拟重点实验室陕西宝鸡721013 中国科学院地球环境研究所黄土与第四纪地质国家重点实验室西安710061 中国科学院地球环境研究所气溶胶化学与物理重点实验室西安710061 陕西师范大学地理科学与旅游学院西安710062 长安大学干旱区地表水文和生态效应教育部重点实验室西安710054 平顶山学院资源与环境科学学院河南平顶山467000

为了揭示西安地区全新世环境变化和黄土地层的侵蚀期,利用野外调查和化学分析等方法,研究了西安地区全新世黄土与古土壤发育时的气候变化和不同气候阶段的土壤侵蚀。通过野外调查,在西安白鹿塬区发现了黄土塬区罕见的3个层次的全新世中... 详细信息

为了揭示西安地区全新世环境变化和黄土地层的侵蚀期,利用野外调查和化学分析等方法,研究了西安地区全新世黄土与古土壤发育时的气候变化和不同气候阶段的土壤侵蚀。通过野外调查,在西安白鹿塬区发现了黄土塬区罕见的3个层次的全新世中期古土壤,整个全新世黄土剖面可分为5.,表明黄土塬区全新世气候变化及沙尘暴活动与河谷地区一样可分为5.阶段。土层氧化物、微量元素、CaCO_(3)含量和磁化率测定结果显示,西安白鹿塬区全新世85.0~6000年和5.00~3100年古土壤发育时较10000~85.0年、6000~5.00年和3100年以来的黄土发育时夏季风活动强,降水量多,气候湿润,沙尘暴活动弱。中全新世85.0~6000年间发育的S_(02)古土壤中Fe_(2)O_(3)和Al_(2)O_(3)有一定富集,该层土壤类型相当于黄棕壤,指示当时年平均降水量较现今多15. mm左右。虽然沙尘暴活动很弱的间冰期是黄土地层理论上的侵蚀期,但是实际上这一时期的土壤侵蚀很弱。全新世黄土的侵蚀主要发生在气候冷干时期,不是发生在温湿时期。全新世中期6000~5.00年间的黄土侵蚀率一般大于堆积率,使得广大地区全新世中期的薄层黄土在绝大多数地区受到侵蚀而消失。全新世中期薄层黄土发育时气候变冷干引起的植被退化是当时土壤侵蚀加强和出现侵蚀期的原因。

关键词：全新世黄土与古土壤气候变化全新世土壤侵蚀西安地区