16 research outputs found

    The Discussion on the Governance Structure of Securities Investment Funds and Empirical Research on Performance in china

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    论文摘要 目前来看,我国的投资基金治理结构仍然存在着比较大的问题。这已经成了制约我国投资基金业进一步发展的“瓶颈”。如何行之有效的解决这一“瓶颈”仍是我国投资基金业研究的重要课题之一。 本文从基金治理结构的理论回顾入手,简要介绍了投资基金的特点和分类。以投资基金的治理结构为切入点,对基金治理结构的五要素进行了简要剖析,重点分析了影响基金治理结构的三大要素—基金投资人、管理人和托管人,并逐一分析了三种委托—代理模式的优劣。 在此基础上,从投资基金的“金三角”和管理模式入手,对我国证券投资基金业的现状进行了分析,指出我国基金业还存在着诸如独立董事制度效果不明显、基金托管人对基金管理人监督不到...ABSTRACT Currently, security investment funds in China share some important problems in their governance. This has been a “bottleneck” that restrains their development. How to settle this “bottleneck” is still an important issue in the security investment fund industry. This article starts from review of theories on fund governance; briefly introduce characteristics and categorie...学位:工商管理硕士院系专业:管理学院工商管理教育中心(MBA中心)_工商管理硕士(MBA)学号:2005130130

    类泛素蛋白及其中文命名

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    泛素家族包括泛素及类泛素蛋白,约20种成员蛋白.近年来,泛素家族领域取得了迅猛发展,并已与生物学及医学研究的各个领域相互交叉.泛素家族介导的蛋白质降解和细胞自噬机制的发现分别于2004和2016年获得诺贝尔奖.但是,类泛素蛋白并没有统一规范的中文译名. 2018年4月9日在苏州召开的《泛素家族介导的蛋白质降解和细胞自噬》专著的编委会上,部分作者讨论了类泛素蛋白的中文命名问题,并在随后的\"泛素家族、自噬与疾病\"(Ubiquitinfamily,autophagy anddiseases)苏州会议上提出了类泛素蛋白中文翻译草案,此草案在参加该会议的国内学者及海外华人学者间取得了高度共识.冷泉港亚洲\"泛素家族、自噬与疾病\"苏州会议是由美国冷泉港实验室主办、两年一度、面向全球的英文会议.该会议在海内外华人学者中具有广泛影响,因此,参会华人学者的意见具有一定的代表性.本文介绍了10个类别的类泛素蛋白的中文命名,系统总结了它们的结构特点,并比较了参与各种类泛素化修饰的酶和它们的生物学功能.文章由45名从事该领域研究的专家合作撰写,其中包括中国工程院院士1名,相关学者4名,长江学者3名,国家杰出青年科学基金获得者18名和美国知名高校华人教授4名.他们绝大多数是参加编写即将由科学出版社出版的专著《泛素家族介导的蛋白质降解和细胞自噬》的专家

    CSR的辐射屏蔽设计(英文)

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    CSR(cooling storage ring)按计划将于2005年底建成调束,届时从~(12)C到~(238)U的重离子将可以分别被加速到900和400MeV的能量。HIRFL(兰州重离子加速器Heavy Ion Research Facility in Lanzhou)将用作CSR的注入器。为了CSR的屏蔽设计,本文利用现有的实验数据计算了由于束流损失产生的中子及其能谱、角分布,同时也估算了屏蔽体外表面的中子剂量、环境中子剂量及天空返照中子剂量。在源项计算中使用了400MeV/u~(12)C+Cu反应的中子产额、能谱、角分布的实验数据。计算表明,CSR对环境剂量影响最大的是天空返照中子

    离子辐照对聚苯乙烯低温导电特性的影响

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    室温下用 3MeV的硅离子对聚苯乙烯 (PS)进行辐照 ,对辐照后的样品在室温至液氮温度范围的导电特性进行了测量 .结果表明 ,当辐照剂量在 1× 10 1 2 cm- 2 附近 ,PS的室温电阻发生突变 .随着温度的降低 ,PS电阻增大 ,在低辐照剂量下 ,电阻在 15 5K附近急剧增加 .对于高辐射剂量样品 ,在较高的温度下呈现热激活导电 ,在低温下电子通过隧穿传导 .分析认为 ,PS电阻随温度的变化是由于不同剂量辐照离子在聚合物中形成的对电子传导有贡献的导电中心密度不同 .通过拟合样品的渗流临界特性 ,分析了样品电阻随辐照剂量的变

    K-600中子发生器辐射防护的改进

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    目的 对K -60 0中子发生器原有的辐射防护做出评价 ,提出改进措施。方法 使用高灵敏度中子探测器和γ监测器 ,对中子发生器运行时n、γ辐射进行了全面的测量并对辐射场围周的防护设施进行改造。结果 改造前在中子厅西、南屏蔽墙外表面有贯穿辐射 ,特别是中子发生器建筑物项部表面有明显的贯穿辐射 ,并且在距离辐射源 3 0~ 40m处呈现峰值 ,显示出天空反射的效果。改造后辐射场外部周围贯穿辐射大为减弱。结论 通过改进措施达到了降低贯穿辐射的目

    高频等离子法制取超细Si_3N_4粉末

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    本文述及高频等离子法制取超细Si_3N_4粉末的原理、装置,工艺参数及粉末性能的一些检测结果。利用SiCl_4+NH_3气-气相反应,所得白色粉末含有NH_4Cl晶体,热重分析表明350℃失重停止,280℃失重速率最快,经400~700℃处理后的粉末仍为非晶,不含NH_4Cl,BET测得比表面积为75.8 m~2/g,X光小角度散射法测粒子半径分布主峰R为100~150,且符合正态对数分布规律,平均直径=527;1400℃处理后,X光衍射测得主相为α-Si_3N_4、次相为Si_2N_2O,粒径明显长大,平均直径达1700

    A Finite Element Model to Simulate Defect Formation during Friction Stir Welding

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    In this study, a 3D coupled thermo-mechanical finite element model is developed to predict and analyze the defect formation during friction stir welding based on coupled Eulerian Lagrangian method. The model is validated by comparing the estimated welding temperature, processed zone shape and void size with those obtained experimentally. The results compared indicate that the simulated temperature and the data measured are in good agreement with each other. In addition, the model can predict the plasticized zone shape and the presence of a void in the weld quite accurately. However, the void size is overestimated. The effects of welding parameters and tool pin profile are also analyzed. The results reveal that welding at low welding speed or high tool rotational speed could produce a smaller void. Moreover, compared to a smooth tool pin, a featured tool pin can enhance plastic flow in the weld and achieve defect-free weldment. The results are helpful for the optimization of the welding process and the design of welding tools

    Effect of rotation speed on nugget structure and property of high rotation speed friction stir welded Al-Mn aluminum alloy

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    High rotation speed friction stir welding is a promising low-force welding technique that enables the application of friction stir welding on in situ fabrication and repair. High rotation speed friction stir welding experiments (above 3000 rpm) were conducted on an Al-Mn aluminum alloy. The effect of rotation speed on nugget structure and property was investigated in order to illuminate the process features. The results indicate that a notable increase of nugget size occurs at high rotation speeds of 5000–8000 rpm. With increasing rotation speed, the thermal effect is firstly strengthened and then achieves a steady state. The microstructure evolution is more sensitive to welding temperature as rotation speed varies, and thus, the evolution trends of nugget structure morphology (grain size and substructure distribution density) with rotation speed resemble that of welding temperature. Increasing rotation speed above 4000 rpm effectively improves the nugget hardness due to the enhancement of strain hardening

    Research Progress in Carbon Coating on LiFePO4 Cathode Materials for Lithium Ion Batteries

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    橄榄石结构的LiFePO4具有电压平台平稳、价格低廉、原料丰富和环境友好等优点,得到了人们的广泛关注. 然而,纯LiFePO4的离子和电子导电性较差,其大范围应用受限. 研究表明,对LiFePO4表面进行碳包覆可以有效提升其电化学性能. 结合国内外研究现状,本文综述了不同的碳包覆方法、碳源种类对LiFePO4电化学性能的影响,以及碳包覆提升LiFePO4正极材料电化学性能的作用机制.Olivine-structured LiFePO4 has been received much attention because of its flat voltage profile, low cost, abundant material supply and better environmental compatibility. However, the poor electronic and ionic conductivities have limited its application in industry. One of the best methods to improve the electrochemical performance is carbon coating. In this review, we summarize the recent developments of LiFePO4/C cathode. Moreover, the different effects caused by coating methods and carbon sources, as well as the mechanism of carbon coating on the properties of LiFePO4/C are reviewed.国家科技部973计划(No. 2011CB935900),国家自然科学基金项目(No. 21231005)资助和中央高校基本科研业务费资助作者联系地址:南开大学 化学学院,先进能源材料化学教育部重点实验室,天津化学化工协同创新中心,天津 300071Author's Address: Key Laboratory of Advanced Energy Materials Chemistry Ministry of Education, Collaborative Innovation Center of Chemical Science and Engineering, College of Chemistry, Nankai University, Tianjin 300071, China通讯作者E-mail:[email protected]
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