39 research outputs found

    A Positive Analysis of the Relationship Between Corporate Governance and Performance:On Chinese Listed Companies in Competitive Industry

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    运用深沪两市126家竞争性行业上市公司2002年的数据,从股权结构、董事会结构和高管激励等内外两种治理机制综合考虑了我国公司治理与公司绩效之间的关系。认为多元化股东、外部董事比例和高管激励是公司治理最为重要的三个因素,是影响公司绩效最为显著的变量;第一大股东是否为法人股、独立董事的作用、是否在国外上市对公司绩效没有显著的影响作用。This paper samples 126 listed companies in competitive industries in 2002 to verify the relationship between corporate governance and performance from internal and external governance mechanism.It turns out that decentralized ownership,higher outside director ratio and higher managers' incentives have positive effect on corporate performance,and that whether the top owner is juridical person,the independent director ratio and whether the companies are listed outside of mainland(dont) have significant effect on corporate performance

    我国现行基金税收政策几大疑问探析

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    证券投资基金是一种间接的证券投资方式,委托——代理关系是证券投资基金运作机制的核心,证券投资基金特殊的运作机理对税收制度提出了挑战。我国税法中有关基金征税的内容较少,甚至有所误解,并且在与基金相关的企业所得税、营业税、征税时机和税负公正等方面均存在严重的税制缺陷。本文从税收公平.效率入手,剖析和探讨了以上4个颇有争议的征税问题,以期对我国现行基金税收政策的研究有所裨益。国家自然科学基金资助项目(项目名称:中国金融税制设计与管理研究。项目编号:70373030)

    Design and Optimization of 4H-SiC Based and LC Resonant Wireless Passive Pressure Sensitive Chips for Harsh Environment Applications

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    针对航空发动机、重型燃气轮机等动力设备燃烧室内压力原位测量的需求,设计了一种基于4H-SiC的LC谐振式无线高温压力敏感芯片.以现有SiC微工艺; 水平为基础,利用TCAD软件及多物理场耦合仿真软件,完成了敏感芯片电容、电感、感压膜等主要部件的结构设计、优化,以提高敏感芯片的Q值及耦合强度.; 探讨了电感内置、外置两种设计方案本体电容的大小,并在此基础上提出一种双腔体结构,将本体电容值减小到179. 66; pF.优化后的敏感芯片常温(20 ℃)Q值约为13. 66,100 kPa满量谐振频率变化158. 62 kHz; 1 000 ℃下的Q值为3.; 65,满量变化55. 53 kHz,且1 000; ℃下的热应力较小.这种敏感芯片将可应用于高温压力传感器的制备,为我国自主研制航空发动机、高超发动机、重型燃气轮机等先进动力系统提供支撑.To meet the demand of the in-situ pressure measurement in combustion; chambers of heavy gas turbines and aero-engine,4H-SiC based and LC; resonant wireless passive pressure sensitive chips were designed. To; improve the Q value and couple coefficient,geometric parameters of chips; primary structures, such as the capacitance,inductance,vacuum cavity and; diaphragm,were optimized by numerical analysis with TCAD and; multi-physic field coupled-simulation softwares. Inductors relative; position,out of or inside the vacuum cavity was discussed,based on which; a dual-cavity chip design was proposed,reducing the bulk capacitance to; 179. 66 pF. Q value of sensitve chips fabricated with optimized; structure paramters was 13. 66 and 3. 65 at 20 ℃ and 1 000; ℃,respectively. The variation of the resonance frequency under full; scale 100 kPa was 158. 62 kHz at 20 ℃,which reduced to 55. 53 kHz when; the temperature rose to 1 000 ℃. These optimized chips could be applied; to prepare pressure sensors for harsh environment applications,which; would support the independent development of aero-engines,hypersonic; engines and heavy gas turbines.总装预先研究资助项

    小麦线粒体肌球蛋白的纯化和特性分析

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    一种筛选对虾是白斑综合症病毒中和抗体的新方法

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    用对虾淋巴组织的原代培养细胞与对虾白斑综合症病毒进行相互作用,洗去不能结合的病毒,然后用甲醛固定,再用ELISA法检测所吸附的病毒。当病毒与抗血清保温后,抑制病毒与细胞的吸附能力的抗血清中应含有中和抗体。此方法可以在缺少细胞系的情况下,简便地筛选到中和抗体

    对虾白斑综合症病毒结构蛋白VP28的原核表达和性质研究

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    VP28是对虾白斑综合症病毒(White spot syndrone virus,WSSV)的一个重要的囊膜蛋白。为了便于研究VP28在和宿主细胞相互作用过程中扮演的角色,将VP28基因克隆到一个原核表达系统,对原核表达的VP28的特性进行了研究,并制备了抗VP28的多克隆抗体和单链抗体,对原核表达的和天然病毒的VP28蛋白免疫原性进行了比较。结果表示,原核表达的VP28与天然蛋白具有相似的免疫原性

    对虾白斑综合症病毒结构蛋白VP28的原核表达和性质研究

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    VP2 8是对虾白斑综合症病毒 (Whitespotsyndromevirus ,WSSV)的一个重要的囊膜蛋白。为了便于研究VP2 8在和宿主细胞相互作用过程中扮演的角色 ,将VP2 8基因克隆到一个原核表达系统 ,对原核表达的VP2 8的特性进行了研究 ,并制备了抗VP2 8的多克隆抗体和单链抗体 ,对原核表达的和天然病毒的VP2 8蛋白免疫原性进行了比较。结果表示 ,原核表达的VP2 8与天然蛋白具有相似的免疫原性
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