检索结果-南通市图书馆

Geological settings and metallogenesis of high-grade iron deposits in China

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2021年第5期64卷 691-715页

作者： Zhaochong ZHANG Houmin li Jianwei li Xie-Yan SONG Hao HU lixing li Fengmei CHAI Tong HOU Deru XU State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesBeijing 100083China Institute of Mineral Resources Chinese Academy of Geological SciencesBeijing 100037China State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430074China State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550002China Xinjiang Key Laboratory for Geodynamic Processes and Metallogenic Prognosis of the Central Asian Orogenic Belt Xinjiang UniversityUrumqi 830046China State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China CAS Key Laboratory of Mineralogy and Metallogeny Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China

The predominant types of high-grade iron deposits in China include skarn,sedimentary metamorphic(banded ironformation,BIF-type),continental/submarine volcanic-hosted and magmatic Fe-Ti-Voxide *** on a comprehensive review of current studies on these deposits,this paper suggests that the oxygen concentration in atmosphere played an important role for the formation of BIFs,whereas the tectonic setting and deep magmatic differentiation processes are more important for the other ***,both high temperature and high pressure experiments and melt inclusion studies indicate that during the differentiation,high temperature magmas could develop iron-rich magma via liquid immiscibility but not pure oxide melt("iron ore magma").Fe-P melt could be generated directly by liquid immiscibility under hydrous and oxidized *** formation of high-grade iron deposits is mostly associated with the processes related to multiple stages of superimposition,e.g.,desiliconization and iron enrichment,removal of impurity,and remobilization and re-precipitation of *** to the temporal evolution,the high-grade iron deposit could be divided into multi-episode superimposition type(temporally discontinuous mineralization)and multi-stage superimposition type(temporally continuous mineralization).The former is represented by the sedimentary metamorphic iron deposit,and the latter includes those related to magmatic-hydrothermal fluids(e.g.,skarn,volcanic-hosted and magmatic types).

关键词： High-grade iron deposit Metallogenesis Iron ore magma liquid immiscibility Fe-rich fluid

Discovery of Cu-Ni-Zn-Sn-Fe intermetallic compounds and S-bearing alloys in the Zhaishang gold deposit, southern Gansu Province and its geological significance

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2008年第6期51卷 769-777页

作者： liU JiaJun MAO GuangJian MA XingHua li lixing GUO YuQian liU GuangZhi State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesBeijing 100083China Key Laboratory of lithosphere Tectonics and lithoprobing Technology of Ministry of Education China University of GeosciencesBeijing 100083China No.5 Gold Geological Party of Chinese Armed Police Force Xi’an 710100China

Examination of ores by optical microscope and EPMA from the Zhaishang gold deposit, southern Gansu Province, has revealed an abundance of rare minerals. These include native metals, Cu-Ni-Zn-Sn-Fe polymetallic compounds and S-bearing alloys of Ni, Fe, Zn, Cu and Sn, occurring as native nickel, Zn-Cu alloy, Ni-Zn-Cu alloy, Sn-Zn-Ni-Cu alloy, Zn-Cu-Ni alloy, Zn-Fe-Cu-Sn-Ni alloy, Fe-Ni-S alloy, Sn-Fe-Ni-S alloy, Fe-Zn-Cu-Ni-S alloy, Zn-Ni-Cu-Fe-S alloy and others. Compared with the Zn-Cu alloy minerals discovered previously, these Zn-Cu minerals fall in the α or α+β portion in Zn-Cu alloy phase diagram, and the α portion has higher Cu content. Cu-Ni-Zn-Sn-Fe intermetallic compounds and S-bearing alloy minerals have not been previously reported in the literature. These rare alloys formed in a strongly reducing environment with absent oxygen and low sulfur activities.

关键词： gold deposit native metal polymetallic compound S-bearing alloy geological significance Gansu

Detection of Pb in Tieguanyin tea and ash by laser-induced breakdown spectroscopy

在线全文

学校读者我要写书评

暂无评论

Optoelectronics Letters 2024年第2期20卷 116-121页

作者： li Jingwen YAO lixing SHEN li WANG Cong Tianjin Key Laboratory of Quantum Optics and Intelligent Photonics School of ScienceTianjin University of TechnologyTianjin 300384China1

In this work, laser-induced breakdown spectroscopy(liBS) was applied for the detection of Pb in Tieguanyin tea and ash. Firstly, the Tieguanyin tea and ash containing Pb were prepared, and the difference of intensities of Pb I spectral lines before and after the ashing treatment was studied. It was found that the intensities of Pb I lines increased by 30 times and the standard deviation of background signal decreased by 41% after the ashing treatment. Therefore, the enrichment of Pb element by ashing treatment was used to detect Pb in tea with high sensitivity. Then, the calibration curve of Pb was established using spectral lines without self-absorption, and the determination coefficient(R^(2)) for the linear fitting of calibration curve was 0.979 9. Finally, it was found that the limit of detection of Pb was 233.8 ppb. Compared with the results of other works which detect Pb directly, the enrichment of Pb by ashing treatment improved the detection sensitivity of Pb by about 200 times. In addition, this method can be applied to the high sensitivity detection of other heavy metals, such as Cr, Cd, Hg, etc in plants, Chinese herbal medicine, flour, rice, coal and other solid materials.

关键词： breakdown spectroscopy treatment

A bifunctional wood membrane modified by MoS_(2)/covalent organic framework heterojunctions for effective solar-driven water evaporation and contaminant degradation

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第6期67卷 2111-2120页

作者： Ziwei Cui Jianfei Wu Haoran li Yaning Xu Tiantian Wu lixing Kang Qing Huang Yahui Cai Jianzhang li Dan Tian Co-Innovation Center of Efficient Processing and Utilization of Forest Resources College of Materials Science and EngineeringNanjing Forestry UniversityNanjing210037China Key Laboratory of Multifunctional Nanomaterials and Smart Systems Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou215123China State Key Laboratory of Efficient Production of Forest Resources Beijing Forestry UniversityBeijing100083China

Interfacial solar evaporation technology is considered one of the most promising strategies for alleviating the scarcity of freshwater ***,solar-driven evaporation technology cannot eliminate the pollutants in the residual *** solve this problem,we have prepared a two-in-one solar-driven evaporation/photocatalysis system by decorating MoS_(2)/covalent organic framework(COF)heterojunctions on wood(MoS_(2)/COF-wood).Thanks to the unique porous structure of wood,it provides a strong guarantee for water transport and vapor release during the evaporation *** introduction of MoS_(2) and COFs can promote the breaking of hydrogen bonds between water molecules,which leads to a significant decrease in the enthalpy of evaporation,achieving a water evaporation rate as high as 2.17 kg m^(-2)h^(-1)under 1 sun ***,the resulting MoS_(2)/COF-wood exhibits good salt resistance and *** addition,the heterojunctions formed between COFs and MoS_(2) can effectively inhibit charge carrier complexation and improve the photocatalytic degradation ability of pollutants(over 99%).This study highlights the construction strategy of bifunctional wood-based materials for freshwater production and wastewater remediation.

关键词： covalent organic framework MoS_(2) wood photocatalysis solar-driven evaporation

Superconducting single-photon detector with a speed of 5 GHz and a photon number resolution of 61

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2024年第6期12卷 1328-1333页

作者： TIANZHU ZHANG JIA HUANG XINGYU ZHANG CHAOMENG DING HUIQIN YU YOU XIAO CHAOliN LV XIAOYU liU ZHEN WANG lixing YOU XIAOMING XIE HAO li Shanghai Key Laboratory of Superconductor Integrated Circuit Technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Photon Technology(Zhejiang)Co. Ltd.Jiaxing 314100China

Rapid detection and discrimination of single photons are pivotal in various applications,such as deep-space laser communication,high-rate quantum key distribution,and optical quantum ***,conventional single-photon detectors(SPDs),including semiconducting and recently developed superconducting detectors,have limited detection speed and photon number resolution(PNR),which pose significant challenges in practical *** this paper,we present an efficient,fast SPD with good PNR,which has 64 paralleled,sandwiched superconducting nanowires fabricated on a distributed Bragg *** detector is operated in a compact Gifford–McMahon cryocooler that supports 64 electrical channels and has a minimum working temperature of 2.3 *** combined detector system shows a functional nanowire yield of 61/64,a system detection efficiency of 90%at 1550 nm,and a maximum count rate of 5.2 ***,it has a maximum PNR of 61,corresponding to the operating *** SPD signifies a substantial improvement in quantum detector technology,with potential applications in deep-space laser communication,high-speed quantum communication,and fundamental quantum optics experiments.

关键词： communication photon quantum

Salt-assisted vapor-liquid-solid growth of high-quality ultrathin nickel oxide flakes for artificial synapses in image recognition applications

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第5期17卷 4622-4630页

作者： Hui Zhang Zongjie Shen Alei li lin Wang Qinan Wang Yunfei li Yunlei Zhong Juntong Zhu Yong Zhang Mengjiao Han Dan Tian Chun Zhao lixing Kang Qingwen li School of Physical Science and Technology Shanghai Tech UniversityShanghai 201210China Division of Advanced Materials Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123China College of Energy Soochow Institute for Energy and Materials Innovationsand Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu ProvinceSoochow UniversitySuzhou 215123China Songshan Lake Materials Laboratory Dongguan 523808China School of Advanced Technology Xi’an Jiaotong-Liverpool UniversitySuzhou 215123China College of Materials Science and Engineering Co-Innovation Center of Efficient Processing and Utilization of Forest ResourcesNanjing Forestry UniversityNanjing 210037China

Transition metal oxides have attracted intense interest owing to their abundant physical and chemical *** controlled preparation of large-area,high-quality two-dimensional crystals is essential for revealing their inherent properties and realizing high-performance ***,fabricating two-dimensional(2D)transition metal oxides using a general approach still presents substantial ***,we successfully achieve highly crystalline nickel oxide(NiO)flakes with a thickness as thin as 3.3 nm through the salt-assisted vapor-liquid-solid(VLS)growth method,which demonstrated exceptional stability under ambient *** explore the great potential of the NiO crystal in this work,an artificial synapse based on the NiO-flake resistive switching(RS)layer is ***-term and long-term synaptic behaviors are obtained with external *** artificial synaptic performance provides the foundation of the neuromorphic application,including handwriting number recognition based on artificial neuron network(ANN)and the virtually unsupervised learning capability based on generative adversarial network(GAN).This pioneering work not only paves new paths for the synthesis of 2D oxides in the future but also demonstrates the substantial potential of oxides in the field of neuromorphic computing.

关键词： nickel oxide(NiO)flakes vapor-liquid-solid(VLS)growth memristor synapse generative adversarial network(GAN)

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

中国的城市化水平:现状、挑战和应对

浙江社会科学 2010年第12期 27-34,42页

作者：李力行北京大学国家发展研究院中国经济研究中心

本文总结了中国城市化水平偏低的几个主要原因,并对"土地城市化"与"人口城市化"不均衡的现状进行了具体的阐释。本文发现,城市建成区面积的扩张大大快于常住人口数量的增长,这在一些沿海省份尤为明显,其原因在于地方政府"土地财政"的动... 详细信息

本文总结了中国城市化水平偏低的几个主要原因,并对"土地城市化"与"人口城市化"不均衡的现状进行了具体的阐释。本文发现,城市建成区面积的扩张大大快于常住人口数量的增长,这在一些沿海省份尤为明显,其原因在于地方政府"土地财政"的动机,以及为农民工提供福利和保障的巨大财政压力。本文提出了在"十二五"期间提升城市化水平的一些政策应对,包括加速发展第三产业、扩大城镇新增就业、推进公共服务均等化,同时主动改革土地制度、并创新行政区划管理体制等。

关键词：土地城市化人口城市化土地制度改革户籍制度行政区划改革

在线全文

学校读者我要写书评

暂无评论

高承载能力高传动效率新型针摆行星传动研究

中国机械工程 2005年第7期16卷 565-569页

作者：何卫东李欣李力行大连交通大学大连116028 马里兰大学

研究出一种具有实用价值的新型摆线针轮行星传动———双曲柄环板式针摆行星传动。简述了双曲柄环板式针摆行星传动原理、结构特点,着重论述了其优化设计、效率分析等理论与方法。理论研究及样机性能试验结果证明了双曲柄环板式针摆行... 详细信息

研究出一种具有实用价值的新型摆线针轮行星传动———双曲柄环板式针摆行星传动。简述了双曲柄环板式针摆行星传动原理、结构特点,着重论述了其优化设计、效率分析等理论与方法。理论研究及样机性能试验结果证明了双曲柄环板式针摆行星传动不仅具有很高的承载能力,同时具有较高的传动效率,是一种极具发展前景的传动型式。

关键词：双曲柄环板式针摆行星传动优化设计承载能力效率

双曲柄环板式针摆行星传动降低振动与噪声的优化设计与试验

在线全文

学校读者我要写书评

暂无评论

机械工程学报 2010年第23期46卷 53-60页

作者：何卫东李欣李力行闻邦椿大连交通大学机械工程学院大连116028 东北大学机械工程与自动化学院沈阳110004 马里兰大学马里兰MD20742美国

双曲柄环板式针摆行星传动是一种高承载能力和高传动效率的新型传动装置。它有多种结构型式,从中选择两种主要结构型式,以提高承载能力为目标进行优化设计,研制出样机进行性能试验,它们都具有高的承载能力和高的传动效率。介绍这两种能... 详细信息

双曲柄环板式针摆行星传动是一种高承载能力和高传动效率的新型传动装置。它有多种结构型式,从中选择两种主要结构型式,以提高承载能力为目标进行优化设计,研制出样机进行性能试验,它们都具有高的承载能力和高的传动效率。介绍这两种能传递更大功率且动态特性更优的主要结构型式和进一步提高其动态特性的研究成果。其中,以提高承载能力为目标进行优化设计的三齿轮联动双曲柄四环板针摆行星传动的样机,高转速满负荷工作时的噪声为92 dB;而振动的评级为好。经过以降低振动和噪声为目标的改进优化设计后,高转速满负荷工作时的噪声为85 dB,噪声降低了7 dB,其评级指标也上升为'好';同时样机的振动性能又得到进一步的改善。

关键词：双曲柄环板式针摆行星传动振动噪声优化设计