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Ore-forming Fluid and Metallogenic Mechanism of Wolframite-Quartz Vein-type Tungsten Deposits in South China

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Acta Geologica Sinica(English Edition) 2020年第6期94卷 1774-1796页

作者： NI Pei li wensheng PAN Junyi State Key Laboratory for Mineral Deposits Research Institute of Geo-FluidsSchool of Earth Sciences and EngineeringNanjing UniversityNanjing 210023China

South China is endowed with copious wolframite-quartz vein-type W deposits that provide a significant contribution to the world‘s tungsten production.Mineralization is spatially associated with highly evolved granites,which have been interpreted as products of ancient crustal anatexis.Ore veins are mainly hosted in low-grade metamorphosed quartz sandstone,slate and granitic rocks.The ore minerals mainly comprise wolframite,cassiterite,scheelite and pyrite,with minor molybdenite,arsenopyrite and chalcopyrite.Typical steeply dipping veins can be divided into five zones from top to the bottom,namely:(Ⅰ)thread,(Ⅱ)veinlet,(Ⅲ)moderate vein,(Ⅳ)thick vein,and(Ⅴ)thin out zones.In general,three types of fluid inclusions at room temperature are commonly recognized in wolframite and/or quartz from these veins:two-phase liquid-rich(type L),two-phase CO2-bearing(type CB),and CO2-rich(type C).Comparative microthermometry performed on fluid inclusions hosted in wolframite and associated quartz indicates that most wolframite was not coprecipitated with the coexisting quartz.Detailed petrographic observation and cathodoluminescence(CL)imaging on coexisting wolframite and quartz of the Yaogangxian deposit,show repeated precipitation of quartz,wolframite,and muscovite,suggesting a more complex fluid process forming these veins.Previous studies of H-O isotopes and fluid inclusions suggested that the main ore-forming fluids forming the wolframite-quartz vein-type deposits had a magmatic source,whereas an unresolved debate is centered on whether mantle material supplemented the ore-forming fluids.The variable CO2 contents in the ore-forming fluids also implies that CO2 might have had a positive effect on ore formation.Fluid inclusion studies indicate that wolframite was most likely deposited during cooling from an initial H2 O+Na Cl±CO2 magmatic fluid.In addition,fluid-phase separation and/or mixing with sedimentary fluid might also have played an important role in promoting wolframite deposition.We speculate that these processes deter

关键词： metallogeny wolframite-quartz vein fluid inclusions microthermometry Nanling region

A response to numerical benchmark for solidification of binary alloys: macro-segregation with thermo-solutal convection

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China Foundry 2012年第2期9卷 171-177页

作者： li wensheng Shen Houfa liu Baicheng Key Laboratory for Advanced Materials Processing Technology Ministry of EducationDepartment of Mechanical EngineeringTsinghua University Beijing 100084China

As a necessary step toward the quantitative predictions of macro-segregation commonly found in metal castings,classical experiments and numerical benchmarks have been used to validate a simplified binary- alloy solidification model.The model consists of fully coupled conservation equations for the transport phenomena (heat transfer,solute redistribution,and melt convection)that lead to macro-segregation in a solidifying ingot with a fixed solid phase.Simulations were performed for solidification of either a Pb-48wt.%Sn or a Sn-5wt.%Pb alloy in a rectangular cavity.The present predictions were compared with experimental data and numerical reference results reported in the literature.Subsequently,the model was applied to a numerical benchmark problem described in the literature for solidification of a Sn-10wt.%Pb alloy.Simulation results for flow velocity,liquid fraction evolution,and macro-segregation maps also were compared with literature predictions,showing similar trends.It is concluded that additional comparisons to experimental results are still required to assess more complex solidification models.

关键词： benchmark solidification macro-segregation thermo-solutal convection

Characterizations and mechanical properties of impregnated diamond segment using Cu-Fe-Co metal matrix

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Rare Metals 2012年第1期31卷 81-87页

作者： li, wensheng Zhang, Jie Wang, Shucai Dong, Hongfeng li, Yaming liu, Yi State Key Laboratory of AdvancedNon-Ferrous Materials Lanzhou University of Technology Lanzhou 730050 China

Diamond impregnated Cu-Fe-Co based saw-blade segments are directly processed by vacuum and pressure-assisted sintering at different temperature, with the purpose of reducing the cobalt content in diamond tools. Copper and iron are used as the bonding elements and cobalt-chrome pre-alloyed powder is used as the hardening phase. Effects of sintering temperature on microstructures and mechanical properties of the sintered matrix and diamond graphitization were investigated by X-ray diffraction analysis, electron probe micro-analyzer, universal testing machine, digital Rockwell hardness tester and Raman scattering analyzer. Results showed that microstructures of the sintered matrix were refined and porosities in the sintered matrix were closed to a more spherical-like shape with the increase of the sintering temperature. Densification, hardness and tensile strength of the matrix sintered at 820 °C were 12.75%, 2.72% and 156.38% higher than that of the matrix sintered at 740 °C, respectively. Diamond graphitization was not occurred at 820 °C. The hardness and the tensile strength rose 32.8% and 13.5%, respectively, after 7.5 h ageing treatment. The matrix densification ascent and the dispersed distribution of Co-Cr pre-alloyed powders contributed a hardness improvement and a tensile strength improvement to the Cu-Fe based matrix.

关键词： Cu-Fe-Co based matrix sintering temperature graphitization microstructure mechanical properties

17-4PH不锈钢激光气体渗氮层显微组织与摩擦学性能

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表面技术 2024年第7期53卷 57-63页

作者：刘礼邵磊孙岩茹崔梓烁李克伟李文生山东科技大学材料科学与工程学院山东青岛266590 西北师范大学物理与电子工程学院兰州730070

目的提高17-4PH马氏体沉淀硬化不锈钢的表面硬度及耐磨性。方法采用光纤激光器对17-4PH不锈钢进行激光气体氮化,采用不同激光功率在其表面制备渗氮层。利用光学显微镜(OM)、电子扫描显微镜(SEM)和X射线衍射仪(XRD)等设备分析渗氮层的显... 详细信息

目的提高17-4PH马氏体沉淀硬化不锈钢的表面硬度及耐磨性。方法采用光纤激光器对17-4PH不锈钢进行激光气体氮化,采用不同激光功率在其表面制备渗氮层。利用光学显微镜(OM)、电子扫描显微镜(SEM)和X射线衍射仪(XRD)等设备分析渗氮层的显微组织和相组成;借助显微硬度仪测试渗氮层截面深度方向的硬度;采用多功能摩擦磨损试验机测试基体、渗氮层的摩擦学性能,并通过SEM分析磨痕形貌,揭示基体与渗氮层的磨损机制。结果在渗氮前样品组织为回火马氏体,经激光渗氮后样品表面形成了由板条马氏体组成的熔化区和回火马氏体组成的热影响区构成的渗氮层。经渗氮后,样品的硬度均得到提高。在激光功率3000 W下,渗氮层的表面硬度最高,达到了415HV0.2,约是基体硬度的1.2倍,渗氮层的硬度随着深度的增加呈下降趋势,在深度为2.6mm处其硬度与基体一致。在回火马氏体向板条马氏体转变的相变强化,以及氮原子(以固溶方式进入基体)的固溶强化作用下,提高了渗氮层的硬度。经渗氮后,样品的摩擦因数均高于基体,但渗氮后其磨损量相较于基体有所减少,在激光功率3000W下,其磨损体积最小,相较于基体减少了62%。在激光功率2500W下马氏体转变不完全,在激光功率3500W下渗氮层出现了裂纹,都降低了渗氮层的硬度,其耐磨性也随之减小,且都略低于在3000W下。磨损机制由渗氮前的以黏着磨损为主,转变为渗氮后的以磨粒磨损为主。结论在17-4PH马氏体沉淀硬化不锈钢表面进行激光渗氮后,其表面硬度和耐磨性均得到提高,在激光功率3000W下制备的渗氮层具有较高的表面硬度和优异的耐磨性。

关键词：激光气体渗氮 17-4PH马氏体沉淀硬化不锈钢显微组织表面硬度摩擦学性能

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新时代社会主义核心价值观教育制度化的唯物史观阐释

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中国高校社会科学 2024年第2期 33-41,M0004页

作者：万光侠李文盛山东师范大学山东省社会科学界联合会山东师范大学马克思主义学院济南250358

社会主义核心价值观教育制度化是新时代培育和践行社会主义核心价值观的一个重要命题,蕴含着深刻的马克思主义唯物史观的理论基础、方法论特征和实践路径,对其进行深入探究和阐释,对新时代培育和践行社会主义核心价值观、深入贯彻落实... 详细信息

社会主义核心价值观教育制度化是新时代培育和践行社会主义核心价值观的一个重要命题,蕴含着深刻的马克思主义唯物史观的理论基础、方法论特征和实践路径,对其进行深入探究和阐释,对新时代培育和践行社会主义核心价值观、深入贯彻落实习近平新时代中国特色社会主义思想具有重要意义。

关键词：新时代社会主义核心价值观教育制度化唯物史观

Eff-YOLOv7:一种改进YOLOv7算法的安全帽和安全背心目标检测算法

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长江信息通信 2024年第5期37卷 5-9,32页

作者：李文生三峡大学计算机与信息学院湖北宜昌443000

为了解决现有算法对工地场景下安全帽和安全背心检测存在的漏检及小目标检测效果差的问题,设计与实现一种基于改进YOLOv7的安全帽及背心检测算法,记为Eff-YOLOv7。首先算法在特征提取阶段中使用EfficientViT Module来强化图像的信息提取... 详细信息

为了解决现有算法对工地场景下安全帽和安全背心检测存在的漏检及小目标检测效果差的问题,设计与实现一种基于改进YOLOv7的安全帽及背心检测算法,记为Eff-YOLOv7。首先算法在特征提取阶段中使用EfficientViT Module来强化图像的信息提取;在特征融合阶段提出一种融合全局特征与局部信息的特征融合提取块,使得中间层特征图能更好地结合上下文信息;提出一种新的目标边框定位损失ICIoU Loss,更精细地计算预测目标框与真实目标框之间地位置偏差。为了验证算法的有效性,以通用目标检测数据集MS COCO和自建安全帽和安全背心数据集为基础,大量的实验表明改进算法Eff-YOLOv7在两个数据集上的多个指标如mAP0.5和mAP0.5:0.95上相较于YOLOv7算法均有大幅提升,为高精度安全帽和安全背心检测提供了一种新的方法。

关键词： YOLOv7 目标检测 ICIoU 安全帽检测安全背心检测

维普期刊数据库博看期刊

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高熵形状记忆合金相变行为研究现状

稀有金属材料与工程 2024年第3期53卷 848-855页

作者：赵燕春冯远飞冯力李文生史亚鹏寇生中段望春兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室甘肃兰州730050 兰州理工大学温州泵阀工程研究院浙江温州325105 甘肃省机械工程研究院增材制造与新材料事业部甘肃兰州730000

随着先进工程技术对形状记忆合金性能要求的不断提高,传统形状记忆合金愈发难以满足要求,高熵形状记忆合金应运而生,引起了研究者的极大关注。高熵形状记忆合金相较于传统形状记忆合金具有显著提高的可回复应变、屈服强度、高温物相稳... 详细信息

随着先进工程技术对形状记忆合金性能要求的不断提高,传统形状记忆合金愈发难以满足要求,高熵形状记忆合金应运而生,引起了研究者的极大关注。高熵形状记忆合金相较于传统形状记忆合金具有显著提高的可回复应变、屈服强度、高温物相稳定性和超弹性等特性,具有广阔的应用前景。本文对高熵形状记忆合金的研究现状、马氏体相变和形状记忆效应等进行了简要的论述,并对高熵形状记忆合金目前存在的不足和未来的发展进行了展望。

关键词：高熵形状记忆合金形状记忆效应马氏体相变微观组织结构

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石油化工装置低温阀门安装问题探讨

大氮肥 2024年第3期47卷 179-182,186页

作者：李文盛中石化宁波工程有限公司浙江宁波315103

针对石油化工装置低温管道阀门容易发生流向安装错误的问题,通过分析低温闸阀、截止阀、球阀、蝶阀的结构特点,结合工艺设计要求,提出低温阀门的安装原则和要求,并从设计、制造、安装、运行管理等环节入手,探讨低温阀门流向安装易出现... 详细信息

针对石油化工装置低温管道阀门容易发生流向安装错误的问题,通过分析低温闸阀、截止阀、球阀、蝶阀的结构特点,结合工艺设计要求,提出低温阀门的安装原则和要求,并从设计、制造、安装、运行管理等环节入手,探讨低温阀门流向安装易出现错误这一问题的解决方案,为石油化工装置建设过程中低温管道阀门的正确安装提供参考。

关键词：低温管道低温阀门阀门结构阀门安装

Co-Ta共掺杂改善liNiO_(2)正极材料性能研究

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电源技术 2024年第2期48卷 218-223页

作者：李文升马帅许国峰杨明天津蓝天太阳科技有限公司天津300384 中国电子科技集团公司第十八研究所天津300384

采用高温固相烧结对liNiO_(2)正极材料进行了Co与Ta掺杂改性,并对其进行元素含量、晶体结构、形貌、比容量、倍率性能、循环性能、差示扫描量热法(DSC)等测试。结果表明,Co可以改善材料倍率性能,Ta可以细化材料颗粒、提升循环性能。Co... 详细信息

采用高温固相烧结对liNiO_(2)正极材料进行了Co与Ta掺杂改性,并对其进行元素含量、晶体结构、形貌、比容量、倍率性能、循环性能、差示扫描量热法(DSC)等测试。结果表明,Co可以改善材料倍率性能,Ta可以细化材料颗粒、提升循环性能。Co与Ta同时掺杂0.01%(摩尔分数)时,LNCTO-1放电(3 C/0.2 C)容量保持率为82.8%,循环(1 C/1 C)50次后,循环容量保持率为95.3%,热分解温度从189.3℃提升到了199.8℃,显示出了优良的综合性能。

关键词：锂离子电池 Co-Ta共掺杂正极材料