检索结果-南通市图书馆

Distribution and origin of brine-type Li-Rb mineralization in the Qaidam Basin,NW China

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

Science China Earth Sciences 2022年第3期65卷 477-489页

作者： Jiansen LI Tingwei LI yunqi ma Fukun CHEN School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources Qinghai Institute of Salt LakesChinese Academy of SciencesXining 810008China Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lakes Xining 810008China

The Qaidam Basin on the Qinghai-Tibet Plateau is well endowed with a variety of critical metals,such as Li and ***,little is known about the distribution,source,and enrichment mechanisms of these *** this paper,we present results of systematic geochemical and H-O-B isotopic analyses of brines in the Tertiary and Quaternary sediments of the Qaidam *** results reveal that the paleobrines from oil-bearing anticlines at Dafengshan,Nanyishan,Youquanzi,Jiandingshan,and Jianshishan are significantly enriched in Li and Rb,whose contents are 81.1-128.9 mg L^(-1)and 4.5-29.2 mg L^(-1),respectively,reaching levels of economic *** Rb contents(up to 12.5 mg L^(-1))and well-endowment of Li also characterize the Dongtai,Xitai,Yiliping,and Senie salt lakes in the Qaidam *** Tertiary paleobrine average inδD andδ18O at-40.7‰and 2.84‰,*** paleobrine with the highest Li and Rb hasδD andδ^(18)O values close to magmatic ***δ^(11)B values are lower than those of river water but close to those of geothermal fluids,suggesting that replenishment by deep magmatic hydrothermal fluid is most likely the key mechanism for the anomalous enrichment of these elements in the paleobrines,though evaporation and water-rock reactions have contributed to the critical metal *** anomalous enrichment of Li and Rb in modern salt lake brines is closely related to the input of volcanic geothermal *** relatively high Li and Rb contents of intercrystalline brines in salt lakes of the western Qaidam Basin and the increase of Li and Rb contents with increasing depth were caused by upwelling of local paleobrines along the fault zones.

关键词： Li and Rb resources Paleobrine Salt lake brine Hydrogen H-O-B isotopes Qaidam Basin

2023年河南麦区连阴雨过程的数值模式精细化检验评估

在线全文

学校读者我要写书评

暂无评论

气象与环境科学 2024年第1期47卷 66-74页

作者：马蕴琦栗晗吕林宜中国气象局·河南省农业气象保障与应用技术重点开放实验室郑州450003 河南省气象台郑州450003 安阳国家气候观象台河南安阳455000

基于河南省2706个自动气象站降水观测资料及欧洲中期天气预报中心(ECMWF)、中国气象局的中尺度模式预报产品(Cma-MESO)和华东区域气象中心的中尺度模式预报产品(Cma-SH9),从不同量级降水的TS评分和BIAS评分、误差空间分布特征及典型区... 详细信息

基于河南省2706个自动气象站降水观测资料及欧洲中期天气预报中心(ECMWF)、中国气象局的中尺度模式预报产品(Cma-MESO)和华东区域气象中心的中尺度模式预报产品(Cma-SH9),从不同量级降水的TS评分和BIAS评分、误差空间分布特征及典型区域预报偏差日变化特征等方面,检验评估了2023年5月25日至6月5日河南省麦收关键期连阴雨过程的数值模式小时降水预报效果。结果表明:ECMWF对Rh(小时降水量)≥0.1 mm/h的预报表现好,Cma-SH9对Rh≥2 mm/h和Rh≥5 mm/h的预报效果较优,Cma-MESO预报性能较差。对于Rh≥2 mm/h, Cma-SH9对上午和夜间的降水预报效果较优,ECMWF对中午到夜里的预报表现好。各模式都表现出在降水量大值区预报偏差大的特点。Cma-SH9对第一阶段的平均有效降水频次预报与实况最为接近,尤其在西部山区;ECMWF则对第二阶段的预报更贴合实况。尽管此次连阴雨过程中各模式小时降水量和小时降水强度的平均值偏差较大,但并没有表现出显著偏强或偏弱的特征;对于有效降水频次占比预报,ECMWF和Cma-MESO在大多数时次的预报分别表现出显著偏多或显著偏少的特征,Cma-SH9的预报则与实况更为接近。

关键词：连阴雨检验评估小时降水麦收期

Origin of Boron in the Gas Hure Salt Lake of Northwestern Qaidam Basin, China: Evidence from Hydrochemistry and Boron Isotopes

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2021年第2期95卷 531-540页

作者： HAN Jibin XU Jianxin Syed Asim HUSSAIN JIANG Hongchen ma yunqi XU Kai ma Haizhou Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources Qinghai Institute of Salt LakesChinese Academy of SciencesXining 810008China Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lakes Xining 810008China Department of Earth Sciences Karakoram International UniversityGilgitGilgit-Baltistan 15100Pakistan State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesWuhan 430074China

The Gas Hure Salt Lake(GHSL) in the northwestern Qaidam Basin, western China, is rich in boron(B) resources, but its B-resource origin is hardly known. Hydrochemical compositions and B isotope characteristics of different waters were collected around the GHSL, including the river water, stream water, spring water, salt-lake brine, intercrystalline brine, well water, drilling brine, and solar pond brine. The hydrochemical signatures suggest that silicates, carbonates and evaporates are the main B-bearing rocks during the water dynamic. The reservoir estimation of B resources shows that the Kulamulekesay River(KLMR) and the Atekan River(ATKR) contribute annually 18.3 tons and 22.84 tons of B, respectively, with a total amount of 11.72 × 10^(4) tons of B during the past 5.7 ka. In comparison with the known B reservoir(32.96 × 10^(4) tons) in the GHSL, a significant amount of B in the GHSL was probably recharged from deep fluids and sediments around the GHSL. The B concentration and B-enrichment degree are shaped by the evaporation process, which are highly elevated at the carnallite and bischofite stages.

关键词： B-bearing rock weathering evaporation process Holocene Qinghai and Xinjiang provinces

Boron isotopic composition of Paleozoic brachiopod and coeval coral calcites in Yunnan-Guizhou Plateau, China

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2011年第12期54卷 1912-1925页

作者： ma yunqi XIAO YingKai HE maoYong XIAO Jun SHEN Quan JIANG ShengXiang Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China Key Laboratory of Salt Lake Resources and Chemistry Qinghai Institute of Salt Lakes Chinese Academy of Sciences Xining 810008 China State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi ＇an 710075 China Geological Team 1 Yunnan Geoexploration and Development Bureau of Mineral Resources Qujing 655000 China Graduate University of Chinese Academy of Sciences. Beijing 100049. China

Boron isotope values in Paleozoic brachiopods and corals, collected from the Yunnan-Guizhou Plateau, China, can be used to constrain the boron isotope compositions of past oceans. All brachiopod shells and coral samples were screened for diagenetic recrystallization by cathodoluminescence microscopy, trace element geochemistry of B, Fe, Mn, Sr, and scanning electron microscopy. The boron isotope ratios for brachiopods in Silurian, Devonian, Carboniferous, and Triassic calcites are in the ranges 8.9‰-14.0‰, 8.8‰-13.8‰, 10.3‰-16.3‰, and 6.7‰-12.4‰, respectively. The boron isotope ratios of coral calcites in the Silurian, Devonian, and Permian are 9.1‰-12.2‰, 6.1‰-13.8‰, and 9.2‰-16.1‰, respectively. The δ11B values for both brachiopods and corals are significantly lower than those for modern biogenic carbonates, indicating that the Paleozoic oceans were depleted of δ11B by up to 10‰. Our results are consistent with previous published studies. The boron isotope compositions of corals and brachiopods show the consistent trends. The low δ11B values may be explained by an enhanced riverine flux of boron from the continents.

关键词： boron isotope coral brachiopod Paleozoic

Sample preparation for isotopic determination of boron in clay sediments

在线全文

学校读者我要写书评

暂无评论

Chinese Journal Of Geochemistry 2013年第2期32卷 203-211页

作者： ZHANG Yanling XIAO Yingkai ma yunqi ZHUGE Qin LIU Zhiqi HE maoyong LUO Chongguang ma Haizhou Key Laboratory of Salt Lake Resources and Chemistry Qinghai Institute of Salt Lakes Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences

The procedures of sample preparation for isotopic determination of boron in clay sediments is very cumbersome, by far, there haven't been relevant reports on that. In order to establish an effective method for sample preparation, a series of experiments were carried out. In this paper, boron in clay sediments was extracted with HCl solution and purified by two-step ion exchange method. Extracted HCl solution should be adjusted to alkalescency before passing through the Amberlite IRA 743 resin column due to the fact that Amberlite IRA 743 resin absorbs boron only from alkalescent solution. However, a mass of hydroxides of Al and Fe will be precipitated when the extracted HCl solution becomes alkalescent. Hydroxides of Al and Fe have a strong adsorption capacity for boron, which can cause boron isotope fractionation. To treat precipitated hydroxides of Al and Fe, four procedures, namely direct ion exchange (DRIE), decationizing ion exchange (DCIE), once sedimentation ion exchange (OSIE) and repeated sedimentation ion exchange (RSIE) were used and assessed. The influences of the four procedures on separation and extraction and isotopic composition of boron in experimental solutions and clay sediments were also discussed. According to the results, the DRIE, DCIE and OSIE are improper. The result of sample determination indicates that when extracting boron via RSIE, with the increase of precipitation times, there's an obvious decrease in boron content in the precipitated hydroxides while a sharp increase in recovery of boron and it is favorable for weakening the influence of boron isotope fractionation. But the process of RSIE is time consuming and it may introduce boron. It needs further research to establish a more effective sample preparation method for isotopic deter- mination of boron in clay sediments.

关键词：硼同位素组成同位素测定样品制备沉积物粘土离子交换法沉淀时间 HCl溶液

Correlation between δ^(18)O, Sr/Ca and Mg/Ca of coral Acropora and seawater temperature from coral culture experiments

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2014年第5期57卷 1048-1060页

作者： XIAO YingKai LIU WeiGuo ma yunqi ZHANG YanLing HE maoYong LUO ChongGuang LIAO QingQiang Qinghai Institute of Salt Lakes Chinese Academy of Sciences State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Beihai Aquarium

To be used as proxies of seawater surface temperature （SST）, the 61Soc values and Sr/Ca and Mg/Ca ratios of scleractinian coral skeletons must be verified by coral culture experiments in the laboratory. This paper describes a coral culture experiment that was conducted at several seawater temperatures T （21-28℃） using a tandem aquarium system and the new method for depositing coral skeletons grown under controlled conditions. The δ180c values and the St/Ca and Mg/Ca ratios of the cultured coral were measured. We concluded that the δ18Oc values and Sr/Ca and Mg/Ca ratios of the cultured coral are clearly corre- lated with T. The linear regression curve is δ18Oc（‰）=-0.1427×T（℃）-0.1495 （n=18, r=0.955, p〈0.0001）, and the slope of -0.1427‰/°d℃ is at the low end of the range of published values （-0.13-0.29‰/°d℃）. The Sr/Ca ratio decreases with increas- ing T, whereas the Mg/Ca ratio increases with increasing T, indicating a negative correlation between Sr/Ca and Mg/Ca. Their linear regression curves are Sr/Ca（mmol/mol）=-O.O4156×T＋lO.59 （n=15, r=-0.789, p〈0.005） and Mg/Ca （mmol/mol）= 0.04974×T＋2.339 （n=17, r=-0.457, p〈0.05）, respectively, which demonstrate that when Mg/Ca and Sr/Ca are increased by one unit, T increases by 5.19℃and decreases by 15.62℃, respectively. These variations are significantly lower than published values.

关键词： coral culture seawater temperature oxygen isotope microelement ratio

Boron Isotopic Composition of Halite from 46-m-long Sediment Core in the Qarhan Salt Lake,Western China

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2014年第S1期88卷 131-132页

作者： FAN Qishun ma yunqi CHENG Huaide ma Haizhou HAN Fenqing Key Laboratory of Salt Lake Resources and Chemistry Qinghai Institute of Salt LakesChinese Academy of Sciences

Previous studies have investigated the boron isotopic composition of salt lake brines in the Qaidam Basin,western ***,the research on boron isotopic composition of halite is very limited due to halite’s low

关键词： Lake Boron Isotopic Composition of Halite from 46-m-long Sediment Core in the Qarhan Salt Lake,Western China

在线全文

学校读者我要写书评

暂无评论

沉积硼酸盐热作用过程中的硼同位素变化

地质学报 2021年第7期95卷 2160-2168页

作者：彭章旷马云麒彭齐鸣中国地质大学地球科学与资源学院北京100083 中国科学院青海盐湖研究所中国科学院盐湖资源综合高效利用重点实验室青海西宁810008 中国科学院青海盐湖研究所盐湖化学分析测试中心青海西宁810008

建立温度与硼同位素变化的关系是研究沉积硼酸盐成岩-变质作用中硼同位素地球化学行为的关键,这有助于准确认识硼酸盐δ^(11)B值所代表的地质意义。本文以自然产出的三方硼砂和钠硼解石为材料,结合热分解特征研究了不同热作用过程中硼... 详细信息

建立温度与硼同位素变化的关系是研究沉积硼酸盐成岩-变质作用中硼同位素地球化学行为的关键,这有助于准确认识硼酸盐δ^(11)B值所代表的地质意义。本文以自然产出的三方硼砂和钠硼解石为材料,结合热分解特征研究了不同热作用过程中硼同位素变化。200℃下硼酸盐经历结晶水的脱水反应,此过程中三方硼砂和钠硼解石δ^(11)B值分别由6.48±0.14‰降低到5.41±0.27‰和由-13.27±0.11‰降低到-15.93±0.23‰。1‰~3‰的硼同位素变化与自然界观察到的由脱水作用形成的次生硼酸盐比原生硼酸盐δ^(11)B值低2‰~4‰的现象一致。200~300℃间经历羟基的脱水过程,伴随着1‰~2‰的硼同位素降低,此过程中三方硼砂和钠硼解石δ^(11)B值分别由5.41±0.27‰降低到3.73±0.26‰和由-15.93±0.23‰降低到-17.11±0.11‰。300~670℃间硼酸盐经历物相转化过程,三方硼砂和钠硼解石δ^(11)B值分别由3.73±0.26‰升高到4.59±0.08‰和-17.11±0.11‰升高到-16.08±0.20‰。此过程1‰的硼同位素升高是由硼-氧骨架结构改变造成的。本实验结果可以指示沉积硼酸盐的形成过程,以及埋藏过程中的硼同位素变化规律。硼酸盐脱水过程中会形成具有更高δ^(11)B值的流体,其可能显著影响内生硼矿的硼同位素组成,因此讨论硼同位素地质意义不能与海相-非海相环境中的硼同位素组成进行简单对比,需要考虑流体演化过程中的硼同位素变化。

关键词：沉积硼酸盐脱水作用热分解硼同位素变化

基于FPGA的三目半全局匹配算法设计与实现

在线全文

学校读者我要写书评

暂无评论

仪器仪表学报 2021年第12期42卷 202-210页

作者：刘阳冯进良黄伟康世勋马韵琪长春理工大学光电工程学院长春241000

三目立体视觉系统能够克服双目立体视觉系统存在的遮挡等问题,进一步提高立体视觉系统测量精度。然而增加传感器数量会导致匹配算法计算量增大,影响系统实时性,从而限制三目立体视觉系统在各领域的实际应用。为此,本文提出一种三目半全... 详细信息

三目立体视觉系统能够克服双目立体视觉系统存在的遮挡等问题,进一步提高立体视觉系统测量精度。然而增加传感器数量会导致匹配算法计算量增大,影响系统实时性,从而限制三目立体视觉系统在各领域的实际应用。为此,本文提出一种三目半全局立体匹配算法及其硬件计算框架。首先,在对三目立体视觉系统基本模型深入分析的基础上,提出一种硬件友好的半全局匹配算法。随后,根据FPGA硬件并行化计算和流水线处理的特点,对片上系统整体框架及各计算模块结构进行设计。最后,基于Zynq-7000 SoC FPGA搭建一套完整硬件实验系统进行算法实现,分别使用数据集图像和真实场景图像对本文算法进行评估。实验结果表明,本文算法与传统双目半全局匹配算法相比,有效像素填充率提高17.31%,错误率降低13.06%,在真实场景下可实现60 fps实时立体匹配,能够满足各类应用场景的实际需求。

关键词：半全局匹配算法三目立体视觉硬件实时计算现场可编程逻辑门阵列