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Energy conversion and deposition behaviour in gravitational collapse of granular columns
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作者 HUANG Bo-lin WANG Jian +2 位作者 ZHANG Quan LUO Chao-lin CHEN Xiao-ting 《山地科学学报:英文版》 SCIE CSCD 2020年第1期216-229,共14页
The high-density gravitational collapse of granular columns is very similar to the movements of large collapsing columns in nature. Based on the development of dangerous columnar rock mass in fields, granular column c... The high-density gravitational collapse of granular columns is very similar to the movements of large collapsing columns in nature. Based on the development of dangerous columnar rock mass in fields, granular column collapse boundary condition in the physical experiments of this study is a new type of boundary conditions with a single free face and a three-dimensional deposit. Physical experiments have shown that the mobility of small particles during the collapse of granular columns was greater than that of large particles. For example, when particle size was increased from 5 to 15 mm, deposit runout was decreased by about 16.4%. When a column consisted of two particle types with different sizes, these particles could mix in the vicinity of layer interfaces and small particles might increase the mobility of large particles. In the process of collapse, potential and kinetic energy conversion rate is fluctuated. By increasing initial aspect ratio a, the ratio of the initial height of column to its length along flow direction,potential and kinetic energy conversion rate is decreased. For example, as a was increased from 0.5 to 4, the ratio of maximum kinetic energy obtained and total potential energy loss was decreased from47.6% to 7.4%. After movement stopped, an almost trapezoidal body remained in the column and a fanlike or fan-shaped accumulation was formed on the periphery of column. Using multiple exponential functions of the aspect ratio a, the planar morphology of the collapse deposit of granular columns could be quantitatively characterized. The movement of pillar dangerous rock masses with collapse failure mode could be evaluated using this granular column experimental results. 展开更多
关键词 Granular columns Rock collapse Collapse experiments Energy conversion Deposit sequence Deposit prediction
东昆仑西段卡而却卡铁铜多金属矿床成矿模式及找矿模型 预览
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作者 张大明 张爱奎 +4 位作者 屈光菊 逯登军 王磷 丁兆滨 李有录 《西北地质》 CAS CSCD 北大核心 2020年第1期91-106,共16页
卡而却卡铁铜多金属矿床是东昆仑成矿带西段典型矿床,矿床成矿作用复杂,但以往对矿床成矿模式与找矿模型研究薄弱,制约了进一步找矿突破。笔者通过研究卡而却卡矿床成矿特征、成矿物理化学条件、成矿机制和矿床成因等,建立了矿床成矿模... 卡而却卡铁铜多金属矿床是东昆仑成矿带西段典型矿床,矿床成矿作用复杂,但以往对矿床成矿模式与找矿模型研究薄弱,制约了进一步找矿突破。笔者通过研究卡而却卡矿床成矿特征、成矿物理化学条件、成矿机制和矿床成因等,建立了矿床成矿模式及找矿模型。研究认为矿床成矿时代为中三叠世;成矿物质来源于岩浆、围岩和深部花岗斑岩;矿床成因属接触交代型和热液脉型斑岩型隐爆角砾岩型,分属2个不同的成矿系统,即与花岗岩有关的矽卡岩成矿系统和与花岗斑岩有关的热液脉型斑岩型隐爆角砾岩型成矿系统。1∶1万详细地质填图+水系沉积物测量+磁法测量、激电、重力剖面测量是寻找该类型矿床的最佳找矿方法组合。 展开更多
关键词 找矿模型 成矿模式 矿床 卡而却卡 东昆仑
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The occurrences and geochemical characteristics of thorium in iron ore in the Bayan Obo deposit,Northern China
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作者 Xiaozhi Hou Zhanfeng Yang +1 位作者 Zhenjiang Wang Wencai Wang 《中国地球化学学报:英文版》 EI CAS CSCD 2020年第1期139-154,共16页
The Bayan Obo deposit in northern China is an ultra-large Fe–REE–Nb deposit.The occurrences,and geochemical characteristics of thorium in iron ores from the Bayan Obo Main Ore Body were examined using chemical analy... The Bayan Obo deposit in northern China is an ultra-large Fe–REE–Nb deposit.The occurrences,and geochemical characteristics of thorium in iron ores from the Bayan Obo Main Ore Body were examined using chemical analysis,field emission scanning electron microscopy,energy dispersive spectrometer,and automatic mineral analysis software.Results identified that 91.69%of ThO2 in the combined samples was mainly distributed in rare earth minerals(bastnaesite,huanghoite,monazite;56.43%abundance in the samples),iron minerals(magnetite,hematite,pyrite;20.97%),niobium minerals(aeschynite;14.29%),and gangue minerals(aegirine,riebeckite,mica,dolomite,apatite,fluorite;4.22%).An unidentified portion(4.09%)of ThO2 may occur in other niobium minerals(niobite,ilmenorutile,pyrochlore).Only a few independent minerals of thorium occur in the iron ore samples.Thorium mainly occurs in rare earth minerals in the form of isomorphic substitution.Analyses of the geochemical characteristics of the major elements indicate that thorium mineralization in the Main Ore Body was related to alkali metasomatism,which provided source material and favorable porosity for hydrothermal mineralization.Trace elements such as Sc,Nb,Zr,and Ta have higher correlation coefficients with thorium,which resulted from being related to the relevant minerals formed during thorium mineralization.In addition,correlation analysis of ThO2 and TFe,and REO and TFe in the six types of iron ore samples showed that ThO2 did not always account for the highest distribution rate in rare earth minerals,and the main occurrence minerals of ThO2 were closely related to iron ore types. 展开更多
关键词 THORIUM Occurrence state Distribution law Geochemical characteristics Iron ore Bayan Obo deposit
Bank Health Analysis Using Camels Ratio on Company Value in the Banking Sector Are Registered in Sri Kehati Index Period of 2012-2017 预览
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作者 Eddy Winarso Josephine Park 《美中公共管理:英文版》 2020年第1期10-22,共13页
This research was conducted on the banking sector that was registered in the Sri Kehati index from 2012 to 2017,because the banking sector was included in the category of Sustainable and Responsible Investment(SRI)ind... This research was conducted on the banking sector that was registered in the Sri Kehati index from 2012 to 2017,because the banking sector was included in the category of Sustainable and Responsible Investment(SRI)index,so researchers were interested in conducting research on the performance of the bank sector.The analysis uses CAMELS ratio.Data are obtained from annual reports issued by the banking sector that is listed on Sri Kehati index and then processed by using EViews 8.The analysis is carried out partially or simultaneously.From the results of data processing,it is obtained that simultaneously the CAMELS ratio has a value that is very influential on the value of the company as measured by Price to Book Value(PBV)of 87.43%,while the remaining 22.57%are other factors not examined.Partially,only three ratios have an effect on Company Value,namely Capital at 1.93%,Assets at 58.06%,and Liquidity at 67.57%,while other ratios,namely Management(non-performing loans(NPL))and Earnings(Return on Assets(ROA))and Operating Expenses to Operating Income(OEOI)have no effect on Value Company.Then,it can be concluded that the banking sector has a CAMELS ratio value that has a positive influence on Company Value,while partially the management must pay attention to Management ratios as measured by NPL and Earnings as measured by ROA and OEOI according to with regulations issued by Bank Indonesia.In this research period,the banking sector is improving its performance related to NPL and its earnings;therefore,a negative influence on Company Value occurs.It is expected that all ratios in CAMELS will have a positive effect and the following year will be better. 展开更多
关键词 CAMELS PBV capital ADEQUACY ratio(CAR) NPL net profit margin(NPM) ROA OEOI LOAN to deposit ratio(LDR)
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不锈钢板式换热器化学清洗剂评价及现场应用 预览
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作者 黄丽华 何益杉 +2 位作者 王礼梅 黄刚华 江晶晶 《石油与天然气化工》 CAS CSCD 北大核心 2020年第1期118-122,共5页
川渝气田天然气净化厂所使用的MDEA贫富液换热器,结构多为全封闭不锈钢板式换热器,运行后其内部结垢严重,换热效率下降,严重影响了装置的安全平稳运行。针对该MDEA贫富液换热器形成的垢物类型、成分、设备结构材质等因素筛选出一种适合... 川渝气田天然气净化厂所使用的MDEA贫富液换热器,结构多为全封闭不锈钢板式换热器,运行后其内部结垢严重,换热效率下降,严重影响了装置的安全平稳运行。针对该MDEA贫富液换热器形成的垢物类型、成分、设备结构材质等因素筛选出一种适合不锈钢板式换热器的高效化学清洗剂,并在某天然气净化厂现场试验应用。实验结果表明,通过该清洗剂化学清洗后换热器进出口温差增加5℃以上,大大提高了设备换热效率,同时清洗换热器材质腐蚀速率仅0.0476 g/(m^2·h),完全满足化学清洗要求。 展开更多
关键词 不锈钢板式换热器 结垢 换热效率 化学清洗剂
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Genesis of the Wulong gold deposit,Liaoning Province,NE China:Constrains from noble gases,radiogenic and stable isotope studies 预览
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作者 Peng Zhang Linlin Kou +4 位作者 Yan Zhao Zhongwei Bi Deming Sha Renping Han Zhumin Li 《地学前缘:英文版》 CAS CSCD 2020年第2期547-563,共17页
TheWulong lode deposit contains over 80 tonnes of gold with an average grade of 5.35 g/t.It is one of the largest deposits in Dandong City,Liaoning Province in northeast China.Previous studies on the deposit focused o... TheWulong lode deposit contains over 80 tonnes of gold with an average grade of 5.35 g/t.It is one of the largest deposits in Dandong City,Liaoning Province in northeast China.Previous studies on the deposit focused on its geological characteristics,geochemistry,fluid inclusions,and the timing of gold mineralization.However,controversy remains regarding the origin of the ore-forming fluids and metals,and the genesis of the gold deposit.This paper presents zircon UePb and pyrite RbeSr ages and S,Pb,He,and Ar isotopic results along with quartz H and O isotopic data for all litho-units associated with the deposit.Laser ablation inductively coupled mass spectrometry measurements yielded zircon UePb dates for samples of pre-mineralization rocks like granite porphyry dike,the Sanguliu granodiorite,fine-grained diorite,and syn-mineralization diorite,as well as post-mineralization dolerite,and lamprophyre;their emplacement ages are 1261 Ma,1241 Ma,1231 Ma,1201 Ma,1192 Ma,and 1152 Ma,respectively.The pyrite RbeSr isochron age is 1191 Ma,indicating that both magmatism and mineralization occurred during the Early Cretaceous.The d18OH2O values of ore-forming hydrothermal fluids from the quartzepolymetallic sulfide vein stage vary from 4.8&to 6.5&,and the dDV-SMOW values are between67.7&and75.9&,indicating that the ore-forming fluids were primarily magmatic.The noble gas isotope compositions of fluid inclusions hosted in pyrite suggest that the ore-forming fluids were dominantly derived from crustal sources with minor mantle input.Sulfur isotopic values of pyrite vary between 0.2&and 3.5&,suggesting that S was derived from a homogeneous magmatic source or possibly from fluids derived from the crust.The Pb isotopic compositions of sulfides(207Pb/204Pb?15.51 e15.71,206Pb/204Pb?17.35e18.75,208Pb/204Pb?38.27e40.03)indicate that the Pb of the Wulong gold deposit is a mixture of crust and mantle components.Geochronological and geochemical data,together with the regional geological history,indicate that Early Cretaceous mag 展开更多
关键词 The Wulong gold deposit Zircon UePb Pyrite RbeSr HeHeeOeAreSePb isotopes Liaodong Peninsula
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Alteration and mineralization styles of the orogenic disseminated Zhenyuan gold deposit,southeastern Tibet: Contrast with carlin gold deposit 预览
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作者 Huajian Li Qingfei Wang +3 位作者 Jun Deng Lin Yang Chaoyi Dong Huazhi Yu 《地学前缘:英文版》 CAS CSCD 2019年第5期1849-1862,共14页
Orogenic disseminated and Carlin gold deposits share much similarity in alteration and mineralization.The disseminated orogenic Zhenyuan Au deposit along the Ailaoshan shear zone,southeastern Tibet,was selected to cla... Orogenic disseminated and Carlin gold deposits share much similarity in alteration and mineralization.The disseminated orogenic Zhenyuan Au deposit along the Ailaoshan shear zone,southeastern Tibet,was selected to clarify their difference.The alteration and mineralization from the different lithologies,including meta-quartz sandstone,carbonaceous slate,meta-(ultra)mafic rock,quartz porphyry and lamprophyre were researched.According to the mineral assemblage and replacement relationship in all types of host rocks,two reactions show general control on gold deposition:(1) replacement of earlier magnetite by pyrite and carbonaceous material;(2) alteration of biotite and phlogopite phenocrysts in quartz porphyry and lamprophyre into dolomite/ankerite and sericite.Despite the lamprophyre is volumetrically minor and much less fractured than other host rocks,it contains a large portion of Au reserve,indicating that the chemically active lithology has played a more important role in gold precipitation compared to structure.LA-ICP-MS analysis shows that Au mainly occurs as invisible gold in fine-grained pyrite disseminated in the host rocks,with Au content reaching to 258.95 ppm.The diagenetic core of pyrite in meta-quartz sandstone enriched in Co,Ni,Mo,Ag and Hg is wrapped by hydrothermal pyrite enriched in Cu,As,Sb,Au,Tl,Pb and Bi.Different host rock lithology has much impact on the alteration and mineralization features.Carbonate and sericite in altered lamprophyre show they have higher Mg than those developed in other of host rocks denoting that the carbonate and sericite incorporated Mg from phlogopite phenocrysts in the primary lamprophyre during alteration.The ore fluid activated the diagenetic pyrite in meta-quartz sandstone leading the hydrothermal pyrite enriched in Cu,Mo,Ag,Sb,Te,Hg,Tl,Pb and Bi,but the hydrothermal pyrite in meta-(ultra)mafic rock is enriched in Co and Ni as the meta-(ultra)mafic rock host rock contain high content of Co and Ni.However,Au and As shear similar range in both types of host rocks i 展开更多
关键词 Zhenyuan GOLD DEPOSIT DISSEMINATED OROGENIC GOLD DEPOSIT Host-rock ALTERATION Mineralization style Carlin GOLD DEPOSIT
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Using trace elements of magnetite to constrain the origin of the Pingchuan hydrothermal low-Ti magnetite deposit in the Panxi area, SW China
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作者 Yanjun Wang Weiguang Zhu +3 位作者 Hong Zhong Zhongjie Bai Junhua Yao Chong Xu 《中国地球化学学报:英文版》 EI CAS CSCD 2019年第3期376-390,共15页
The Pingchuan iron deposit, located in the Yanyuan region of Sichuan Province, SW China, has an ore reserve of 40 Mt with ~60 wt% Fe. Its genesis is still poorly understood. The Pingchuan iron deposit has a parageneti... The Pingchuan iron deposit, located in the Yanyuan region of Sichuan Province, SW China, has an ore reserve of 40 Mt with ~60 wt% Fe. Its genesis is still poorly understood. The Pingchuan iron deposit has a paragenetic sequence of an early Fe-oxide–Pyrite stage(Ⅰ) and a late Fe-oxide–pyrrhotite stage(Ⅱ). Stage Ⅰ magnetite grains are generally fragmented, euhedral–subhedral, largesized crystals accompanying with slightly postdated pyrite.Stage Ⅱ magnetite grains are mostly unfragmented, anhedral, relatively small-sized grains that co-exist with pyrrhotite. Combined with micro-textural features and previously-obtained geochronological data, we consider that these two stages of iron mineralization in the Pingchuan deposit correspond to the Permian ELIP magmatism and Cenozoic fault activity event. Both the Stage Ⅰ and Ⅱ magnetites are characterized with overall lower contents of trace elements(including Cr, Ti, V, and Ni) than the ELIP magmatic magnetite, which suggests a hydrothermal origin for them.‘‘Skarn-like’’ enrichment in Sn, Mn, and Zn in the Stage Ⅰ magnetite grains indicate significant material contributions from carbonate wall-rocks due to water–rock interaction in ore-forming processes. Stage Ⅱ magnetite grains contain higher Mn concentrations than Stage Ⅰ magnetite grains, which possibly implies more contribution from carbonate rocks. In multiple-element diagrams, the Stage Ⅰ magnetite shows systematic similarities to Kiruna-type magnetite rather than those from other types of deposits. Combined with geological features and previous studies on oxygen isotopes, we conclude that hydrothermal fluids have played a key role in the generation of the Pingchuan low-Ti iron deposit. 展开更多
关键词 SW China Pingchuan IRON DEPOSIT Low-Ti IRON DEPOSIT HYDROTHERMAL MAGNETITE
Geochronology and mineralogy of the Weishan carbonatite in Shandong province,eastern China 预览
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作者 Chen Wang Jianchao Liu +4 位作者 Haidong Zhang Xinzhu Zhang Deming Zhang Zhixuan Xi Zijie Wang 《地学前缘:英文版》 CAS CSCD 2019年第2期769-785,共17页
The Weishan REE deposit is located at the eastern part of North China Craton(NCC),western Shandong Province.The REE-bearing carbonatite occur as veins associated with aegirine syenite.LA-ICP-MS bastnaesite Th-Pb ages(... The Weishan REE deposit is located at the eastern part of North China Craton(NCC),western Shandong Province.The REE-bearing carbonatite occur as veins associated with aegirine syenite.LA-ICP-MS bastnaesite Th-Pb ages(129 Ma)of theWeishan carbonatite show that the carbonatite formed contemporary with the aegirine syenite.Based on the petrographic and geochemical characteristics of calcite,the REEbearing carbonatite mainly consists of Generation-1 igneous calcite(G-1 calcite)with a small amount of Generation-2 hydrothermal calcite(G-2 calcite).Furthermore,the Weishan apatite is characterized by high Sr,LREE and low Y contents,and the carbonatite is rich in Sr,Ba and LREE contents.Theδ13CV-PDB(-6.5‰to-7.9‰)andδ13OV-SMOW(8.48‰-9.67‰)values are similar to those of primary,mantlederived carbonatites.The above research supports that the carbonatite of the Weishan REE deposit is igneous carbonatite.Besides,the high Sr/Y,Th/U,Sr and Ba of the apatite indicate that the magma source of the Weishan REE deposit was enriched lithospheric mantle,which have suffered the fluid metasomatism.Taken together with the Mesozoic tectono-magmatic activities,the NWand NWWsubduction of Izanagi plate along with lithosphere delamination and thinning of the North China plate support the formation of theWeishan REE deposit.Accordingly,the mineralization model of theWeishan REE deposit was concluded:The spatial-temporal relationships coupled with rare and trace element characteristics for both carbonatite and syenite suggest that the carbonatite melt was separated from the CO2-rich silicate melt by liquid immiscibility.The G-1 calcites were crystallized from the carbonatite melt,which made the residual melt rich in rare earth elements.Due to the common origin of G-1 and G-2 calcites,the REE-rich magmatic hydrothermal was subsequently separated from the melt.After that,large numbers of rare earth minerals were produced from the magmatic hydrothermal stage. 展开更多
关键词 Weishan REE DEPOSIT CARBONATITE CALCITE APATITE DEPOSIT model
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矿床学研究中对磁黄铁矿的研究方法及意义 预览
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作者 杨阳 《世界有色金属》 2019年第22期197-199,共3页
通过对国内许多矿床统计发现,斑岩型矿床、矽卡岩矿床、铜镍硫化物矿床中普遍发育大量的磁黄铁矿,因此许多学者选择以磁黄铁矿为切入口对其矿物学特征展开研究,从而以点带面指示出与矿床学相关地质意义。结果表明,通常采用磁性胶法、电... 通过对国内许多矿床统计发现,斑岩型矿床、矽卡岩矿床、铜镍硫化物矿床中普遍发育大量的磁黄铁矿,因此许多学者选择以磁黄铁矿为切入口对其矿物学特征展开研究,从而以点带面指示出与矿床学相关地质意义。结果表明,通常采用磁性胶法、电子探针分析法、X射线粉晶衍射法、LA-ICP-MS原位微区分析法和Re-Os同位素年代学分析法等对磁黄铁矿展开研究,从而识别磁黄铁矿及其类型、判别矿床成因及成矿物质来源。 展开更多
关键词 矿床 磁黄铁矿 矿物学特征 矿床成因
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Geochemical characteristics and genetic type of a lithium ore (mineralized) body in the central Yunnan Province, China 预览
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作者 Bai-dong Sun Jun-ping Liu +6 位作者 Xiao-hu Wang Yan Dao Gui-xiang Xu Xiao-zhuang Xue-qing Guan Wei Wang Dong-hu Song 《中国地质(英文)》 2019年第3期287-300,共14页
Lithium ore (mineralized) bodies in the area A of central Yunnan Province belong to a sedimentary-type, which are controlled by stratum. The studied ore (mineralized) body mainly occurs in the Middle Permian Liangshan... Lithium ore (mineralized) bodies in the area A of central Yunnan Province belong to a sedimentary-type, which are controlled by stratum. The studied ore (mineralized) body mainly occurs in the Middle Permian Liangshan Formation. This work described the morphology, structures, main ore types and geochemical characteristics of this ore body in detail, and discussed the ore-forming material source, occurrence state of lithium and the formation mechanism of lithium ores to clarify the prospecting marks. In the further exploration, comprehensive evaluation of the lithium resources of known bauxite ore bodies in central Yunnan Province should be strengthened, and the exploration of hidden lithium ore bodies should be intensified in order to discover more large and super-large lithium orebodies, which will fill the gap of the national demand for lithium resources, and promote the national defense construction and new energy industry development. 展开更多
关键词 Sedimentary-type lithium DEPOSIT STRATIFIED DEPOSIT GEOCHEMICAL characteristics METALLOGENIC mechanism Mineral resources exploration engineering Yunnan PROVINCE China
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地质普查找矿及矿床地质勘探分析 预览 被引量:1
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作者 赵建平 《世界有色金属》 2019年第7期67-67,69共2页
矿物资源的开发效率以及利用效率容易受到自然环境以及复杂地理结构的影响。而提升矿物资源开发效率以及利用效率的关键就是提高相关部门的地质普查找矿水平以及矿场地质勘探水平。基于此,本文重点以文山大腰店钻探施工为例,针对地质普... 矿物资源的开发效率以及利用效率容易受到自然环境以及复杂地理结构的影响。而提升矿物资源开发效率以及利用效率的关键就是提高相关部门的地质普查找矿水平以及矿场地质勘探水平。基于此,本文重点以文山大腰店钻探施工为例,针对地质普查找矿以及矿床地质勘探进行了详细的分析,旨在提升文山大腰店矿区矿产的开发与利用效率,带动祥云县经济的发展,以供参考。 展开更多
关键词 地质普查找矿 矿床 地质勘探
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基于极限平衡条件的沟道泥石流启动条件研究 预览
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作者 张国帅 王晓亮 夏建新 《力学与实践》 北大核心 2019年第5期565-570,共6页
沟道泥石流启动的力学本质为沟道中的堆积体所受剪切力克服摩擦力的过程。本文通过堆积体临界状态的受力平衡分析确立颗粒堆积体的临界平衡条件,发现堆积结构稳定性受坡度、颗粒内摩擦系数、堆积高度和水流速度共同作用。在此基础上通... 沟道泥石流启动的力学本质为沟道中的堆积体所受剪切力克服摩擦力的过程。本文通过堆积体临界状态的受力平衡分析确立颗粒堆积体的临界平衡条件,发现堆积结构稳定性受坡度、颗粒内摩擦系数、堆积高度和水流速度共同作用。在此基础上通过文献中的系列实验数据分析拟合得到了一个泥石流启动的临界流速条件,相关结果和文献中的两个系列实验结果吻合良好,有望为沟道泥石流启动提供一定的支撑。 展开更多
关键词 有效摩擦系数 沟道泥石流 堆积体 启动条件
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共享单车租赁的法律问题研究 预览
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作者 郭辉 张文强 《保定学院学报》 2019年第1期49-53,共5页
共享单车的出现一定程度上改变了人们的出行方式,具有诸多优点。但共享单车在运营过程中也存在诸多问题,如共享单车租承双方权利义务尚未明确、共享单车租赁过程中人身损害的责任承担缺乏明确规范、共享单车资金安全监管空白、共享单车... 共享单车的出现一定程度上改变了人们的出行方式,具有诸多优点。但共享单车在运营过程中也存在诸多问题,如共享单车租承双方权利义务尚未明确、共享单车租赁过程中人身损害的责任承担缺乏明确规范、共享单车资金安全监管空白、共享单车安全欠缺有效规制、单车使用人信息安全存在泄露危险等。为维护共享单车租赁中各方权益,需明确共享单车租承双方权利义务、理清共享单车租赁过程中人身损害责任、严格共享单车资金安全保障、规范单车使用人信息安全保护等。 展开更多
关键词 共享单车 租赁 押金 监管
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Geochemistry and zircon U-Pb chronology of quartz porphyry in Yuejinshan Fe-polymetallic deposit of Heilongjiang 预览
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作者 JIN Ye CUI Bo +6 位作者 WANG Li YANG Baihui YIN Yue LI Qing WANG Shuo CHEN Xiaohang LIU Xiang 《世界地质:英文版》 2019年第2期67-77,共11页
Quartz porphyry in Yuejinshan Fe-polymetallic deposit is one of the rock masses, which formed the granite belt relating to the late Yanshanian skarn-type Fe-polymetallic deposits in the eastern Heilongjiang, and is al... Quartz porphyry in Yuejinshan Fe-polymetallic deposit is one of the rock masses, which formed the granite belt relating to the late Yanshanian skarn-type Fe-polymetallic deposits in the eastern Heilongjiang, and is also closely related to the metallogenic space of the Fe-polymetallic deposits. Quartz porphyry has the zircon U-Pb concordia age of 125.0±1.1 Ma, overall showing high Si (SiO 2=74.48%-- 75.00%), rich alkaline (Na2O+K 2O=7.93%-8.17%, K 2O/Na 2O=1.39-- 1.46), and poor Mg (MgO=0.27%-- 0.31%), with the A/CNK value being 0.95--0.99, having the characteristics of obvious enrichment of LREE and medium Eu negative anomaly (0.69-- 0.74), indicating that the rock belongs to quasi-aluminous high potassium calc-alkaline series and has the same characteristics as those of the I-type granite. The rock is also characterized by the enrichment of LILE and active incompatible elements, and depletion of HFSE such as Nb, Ta, P and Ti, with the Mg # value being 32--- 37, indicating that the rock originated from partial melting of crustal materials. It can be concluded from the above characteristics or data and from the distribution of contemporary magmatic rocks in the area, that quartz porphyry in Yuejinshan Fe-polymetallic deposit was formed in a tectonic background of the subduction of the paleo-Pacific plate in late Yanshanian. 展开更多
关键词 quartz PORPHYRY ZIRCON U-PB age GEOCHEMISTRY Yuejinshan Fe-polymetallic deposit
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粤北张屋坪锑矿点的矿床成因与找矿前景浅析 预览
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作者 黄红亮 《世界有色金属》 2019年第6期293-294,共2页
粤北地区矿产资源丰富,特别是粤北曲仁构造盆地,属南岭成矿带的核心区域,区内曾发现多个大中型金属矿床,小型矿床更是不计其数。通过分析张屋坪矿区的区域及矿区地质背景,在此基础上,对矿区的矿体特征和矿石特征进行研究,粗略分析其成... 粤北地区矿产资源丰富,特别是粤北曲仁构造盆地,属南岭成矿带的核心区域,区内曾发现多个大中型金属矿床,小型矿床更是不计其数。通过分析张屋坪矿区的区域及矿区地质背景,在此基础上,对矿区的矿体特征和矿石特征进行研究,粗略分析其成矿机理,总结深部找矿经验。张屋坪锑矿点与区内赤老顶锑矿床同属于一个成矿带,并且具有相似的成矿地质条件。根据矿床地质特征,沿矿床走向及倾向的延长方向、矿床两侧的次级断裂构造以及矿区深部,均具有十分重要的找矿意义。 展开更多
关键词 锑矿 矿床 找矿
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Relations of Uranium Enrichment and Carbonaceous Debris within the Daying Uranium Deposit, Northern Ordos Basin
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作者 Fan Zhang Yangquan Jiao +2 位作者 Liqun Wu Hui Rong Longhui Wang 《地球科学学刊:英文版》 SCIE CAS CSCD 2019年第1期142-157,共16页
Carbonaceous debris(CD)is widely distributed in the sandstone of the Daying Uranium Deposit,northern Ordos Basin,and coexists with uranium minerals,which provides a favorable case for studying their relationship.Vitri... Carbonaceous debris(CD)is widely distributed in the sandstone of the Daying Uranium Deposit,northern Ordos Basin,and coexists with uranium minerals,which provides a favorable case for studying their relationship.Vitrinite reflectance(VR),macerals,moisture,volatile matter,ash,total sulfur(St)and uranium concentration of CD within the sandstone were studied.The results show that VR ranges from 0.372%Ro to 0.510%Ro with an average value of 0.438%Ro,indicating that CD is in the stage of lignite.The contents of vitrinite(V),inertinite(I)and minerals range from 83.18%–99.48%,0–7.70%,and 0.34%–15.72%,respectively,with the corresponding average value of 95.51%,1.34%,and 3.15%,respectively which indicates that V is the major maceral.Moisture on air dried basis(Mad),volatile matter yield on dry,ash-free basis(Vdaf),ash yield on dried basis(Ad)and St mostly range from 7.95%–16.09%,44.70%–66.54%,4.84%–26.24% and 0.24%–1.12%,respectively,while their average values are 12.43%,53.41%,16.57% and 0.77%,respectively.It suggests that CD is of medium-high moisture,super-high volatile matter,low-medium ash and low sulfur.Uranium concentration ranges from 29 ppm to 92 ppm with an average value of 50 ppm,and uranium concentration increases with the decreased distance to CD.On the whole,Mad and Vdaf decrease with increasing burial depth,which indicates that CD experienced the burial metamorphism.However,Mad and Vdaf obviously decrease in uranium-rich areas whereas Ad and St noticeably increase.Comprehensive studies suggest that there is a certain relationship between uranium enrichment and CD.CD in the stage of lignite helps the adsorption of uranium.On one hand,radioactivity uranium enrichment makes organic matter maturation increase with a decrease in moisture and volatile matter.On the other hand,an increase in organic matter maturation,caused by radioactivity uranium enrichment,results in an increase in uranium minerals,which is instructive in the study of regional uranium mineralization and metallogenic regularity. 展开更多
关键词 CARBONACEOUS DEBRIS coal property parameters Daying URANIUM DEPOSIT ORDOS Basin
An integrated ore prospecting model for the Nyasirori gold deposit in Tanzania 预览
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作者 Yang-sen Yuan Shui-ping Li +5 位作者 Jun Peng Jian-tao Si Hua Cheng Jin Sun Jian-zheng Wei Jiang-bo Shao 《中国地质(英文)》 2019年第4期407-421,共15页
The Nyasirori gold deposit,located in the middle-western end of the Musoma-Mara Archean greenstone belt in Tanzania,is a tectonic altered rock type gold deposit controlled by shear tectonic zone.This work conducted hi... The Nyasirori gold deposit,located in the middle-western end of the Musoma-Mara Archean greenstone belt in Tanzania,is a tectonic altered rock type gold deposit controlled by shear tectonic zone.This work conducted high-precision ground magnetic measurements to delineate fault structures and favorable prospecting targets,utilized induced polarization(IP)intermediate gradient to roughly determine the distribution and extension of the tectonic altered zone and gold ore(mineralized)bodies,and further carried out IP sounding and magnetotelluric sounding to locate the tectonic altered zone and gold ore(mineralized)bodies.The anomalous gradient belt of the combination of positive and negative micromagnetic measurements reflects the detail of shallow surface tectonic alteration zone and gold mineralization body.Micromagnetic profile anomalies indicate the spatial location and occurrence of concealed tectonic alteration zone and gold(mineralized)ore bodies.Soil geochemical measurements indicate that the ore-forming element Au correlates well with As and Sb,and As and Sb anomalies have a good indication to gold orebodies.Based on the multi-source geological-geophysical-geochemical information of the Nyasirori gold deposit,this work established an integrated prospecting model and proposed a set of geophysical and geochemical methods for optimizing prospecting targets. 展开更多
关键词 GEOPHYSICS GEOCHEMISTRY Prospecting model Gold deposit Archean greenstone belt Tectonic altered rock type Mineral exploration engineering Nyasirori Tanzania
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A new type U-Th-REE-Nb mineralization related to albitite:A case study from the Chachaxiangka deposit in the northeastern Qaidam Basin of China 预览
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作者 Jun Zhong Chao-nan Hu +4 位作者 Hong-hai Fan Yu-qi Cai Qing Chen Jin-yong Chen Yan-ning Meng 《中国地质(英文)》 2019年第4期422-438,共17页
The U-Th-REE-Nb(Ta)-polymetallic mineralization is generally related to either the silica-undersaturated syenites,the silica-oversaturated alkaline/peralkaline granites or igneous carbonatites.In this study,the author... The U-Th-REE-Nb(Ta)-polymetallic mineralization is generally related to either the silica-undersaturated syenites,the silica-oversaturated alkaline/peralkaline granites or igneous carbonatites.In this study,the authors report a new mineralization type,which is related to the magmatic-hydrothermal albitite(with mineral assemblage predominated by albite with volume content>90%),as exemplified by the Chachaxiangka deposit in Qinghai Province of China.The Chachaxiangka deposit is the first albititerelated U-Th-REE-Nb deposit recognized in China and the mineralization can be divided into 3 types:the vein-type,the disseminated veinlet type and breccia type,of which the former 2 are predominant.Three mineralization stages can be identified according to the detailed mineralogical analyses,including the magmatic stage,main hydrothermal mineralization stage and post-ore stage.By comprehensive analyses of the mineralogical,major and trace element compositions,the authors suggest that the albitite vein is magmatic-hydrothermal in origin and both the magmatic evolution and overprint of the hydrothermal fluids play important roles in the formation of the albitite and related polymetallic mineralization.Phase separation between the silicate melt and carbonate/phosphate melt might take place in the magmatic stage,yet the immiscibility between the silicate melt and chloride-dominated fluids is the most important mechanism for the REE mineralization and also causes the Nb-Th re-mobilization and enrichment.The red color of the albitite aplite vein is an eye-catching prospecting mark in the field and more mineralization can be expected at depth and in the surrounding areas.The discovery of the new albitite type U-Th-REENb mineralization give rise to new ideas during future U-Th-REE-Nb exploration,not only in the Qaidam-Altun belt,but also other areas across China. 展开更多
关键词 Albitite type mineralization Chachaxiangka Magmatic-hydrothermal mineralization system U-Th-REE-Nb deposit Qaidam-Altun UHPM belt China
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Mafic-ultramafic magma activity and copper-nickel sulfide metallogeny during Paleozoic in the Eastern Kunlun Orogenic Belt,Qinghai Province,China 预览
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作者 Zhao-wei Zhang Ya-lei Wang +4 位作者 Chi-yuan Wang Bing Qian Wen-yuan Li Jiang-wei Zhang Min-xin You 《中国地质(英文)》 2019年第4期467-477,共11页
The Eastern Kunlun Orogenic Belt(EKOB)has a complex geological structure and diverse magmatic activities,which are closely related to the Qaidam Basin and the Tethys tectonic evolution.There are at least 3 stages mafi... The Eastern Kunlun Orogenic Belt(EKOB)has a complex geological structure and diverse magmatic activities,which are closely related to the Qaidam Basin and the Tethys tectonic evolution.There are at least 3 stages mafic-ultramafic rocks occurred in the Early Paleozoic in EKOB.The first stage is the Later-Silurian to Early Devonian,represented by the giant Xiarihamu super large magmatic Cu-Ni deposit,containing about 1.18 million metric tons(Mt)of nickel with average grades of 0.65%Ni,and its age of ore-forming pyroxene peridotite is 411 Ma;The second stage is the Early Carboniferous,represented by the large Shitoukengde magmatic Cu-Ni sulfide deposit,and its ore-forming age of the olivine websterite is 334 Ma;The third stage of mafic-ultramafic rocks occurred mainly during the Middle-Late Triassic,represented by Xiaojianshan,Lalinggaoli,and Kaimuqi complexes,and no economical ore bodies have been found in this period.The authors summarized the difference between the ore-bearing and the nonmineralized mafic-ultramafic rocks in the EKOB.The olivine of the ore-bearing complexes contains higher MgO and SiO2 content but lower FeO and CaO contents,and the clinopyroxene of ore-bearing complexes contains lower FeO and CaO contents.Crustal sulfur contamination is key to the formation of the giant Xiarihamu Ni deposit,and crustal sulfur contamination degree of the giant magmatic Ni deposit is higher than that of large Ni deposit.The above indicators could guide the exploration and evaluation of similar deposits in the EKOB. 展开更多
关键词 Early Devonian Early Carboniferous Mafic-ultramafic complexes Cu-Ni deposit Mineral exploration engineering Eastern Kunlun orogenic belt QINGHAI China
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