57 research outputs found

    Syntheses and Reactivity of Ruthenium Complexes Containing B-Phenylethynyl or Phenyl Substituted Boratabenzene Ligands

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    硼杂苯(Bb)(boratabenzene)是含6个电子的芳香性杂环,其配位行为与化学性质和环戊二烯基离子(Cp)类似,可作为Cp的等电子配体,又可以方便地通过改变硼上的取代基调节配体的电子性质和空间位阻,从而调控相应配合物的反应性质。本论文合成了一系列的硼杂苯钌配合物及其相关化合物,并对其进行了表征,同时对于部分产物的反应性质进行了研究。论文分为以下三个部分: 第一章为绪论,结合本论文核心内容简要介绍了硼杂苯、硼杂苯配合物以及半夹心型环戊二烯基钌配合物(η5-C5R5)RuXL2研究进展,同时阐述了本论文的设想与主要研究内容。 第二章为硼杂苯钌配合物(6-...Boratabenzenes are six-membered aromatic borataheterocycle bearing six π-electrons, which are isoelectronic and isostructural with the ubiquitous cyclopentadienyl ligands. Their coordination properties are similar to that of Cp. In addition, it is easier to modulate their electronic contributions by the choice of the exocyclic substituent on boron.In this thesis, a series of half-sandwich rutheniu...学位:理学硕士院系专业:化学化工学院_有机化学学号:2052009115144

    A Study on Vietnamese,Thail and Indonesian Enviroment of Foreign Direct Investment

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    21世纪以来,东南亚国家因经济的对外开放、资源的廉价、经济的高速增长等因素吸引了外国直接投资(FDI)的快速流入。与此同时,我国人民币升值预期增强,“中国-东盟自由贸易区”正式建成等因素大大推动我国企业“走出去”,因此对东盟国家的外国直接投资环境进行研究已刻不容缓。 本文运用定性研究与定量分析相结合的方法,以东南亚的越南、泰国、印度尼西亚为案例,研究影响这三国外国直接投资流入的投资环境,并对三国的投资环境进行综合性评价与分析。文章首先介绍了东盟三国外国直接投资环境的现状与发展进程。继而笔者在以往学者研究基础上,将影响东盟三国FDI的十个因素分为与创造收入有关和与降低成本有关的两大类进行研究,...As a result of economic opening-up,low-cost resources and high economic growth,Southeast Asian countries face a rapid inflow of foreign direct investment since the 21st century. Chinese enterprises are also planning "going global" as the appreciation of RMB and the set up of “China-ASEAN Free Trade Area”, so it is essential to research the foreign direct investment environment in ASEAN countries. ...学位:经济学硕士院系专业:南洋研究院_世界经济学号:2552007115169

    CDK5-dependent BAG3 degradation modulates synaptic protein turnover

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    阿尔茨海默病(AD)是严重威胁人类健康的重大神经系统疾病,AD的发生发展与衰老密切相关,目前临床治疗方法十分有限。因此迫切需要从AD致病早期入手,发现和鉴定导致AD神经功能紊乱的机制和靶点,为AD的早期防治提供基础。张杰教授及其团队从高通量磷酸化蛋白质组学入手,系统研究了CDK5在神经细胞中的磷酸化底物,鉴定出了在蛋白质量控制中发挥重要功能的BAG3蛋白是CDK5的全新底物。课题组从磷酸化蛋白质组学入手,发现和阐明了细胞周期蛋白激酶5(CDK5)通过调控BAG3在维持突触蛋白水平调控中的作用机制,及其在阿尔茨海默病(AD)发生发展中的机理。 该研究是多个团队历时8年合作完成的,香港中文大学的周熙文教授、美国匹兹堡大学的Karl Herrup教授、美国Sanford-Burnham研究所的许华曦教授、美国梅奥医学中心的卜国军教授,厦门大学医学院的文磊教授、张云武教授、赵颖俊教授、薛茂强教授,军事医学科学院的袁增强教授等都参与了该工作。 厦门大学医学院2012级博士生周杰超等为文章的第一作者,张杰教授为通讯作者。Background Synaptic protein dyshomeostasis and functional loss is an early invariant feature of Alzheimer’s disease (AD), yet the unifying etiological pathway remains largely unknown. Knowing that cyclin-dependent kinase 5 (CDK5) plays critical roles in synaptic formation and degeneration, its phosphorylation targets were re-examined in search for candidates with direct global impacts on synaptic protein dynamics, and the associated regulatory network was also analyzed. Methods Quantitative phospho-proteomics and bioinformatics analyses were performed to identify top-ranked candidates. A series of biochemical assays were used to investigate the associated regulatory signaling networks. Histological, electrochemical and behavioral assays were performed in conditional knockout, shRNA-mediated knockdown and AD-related mice models to evaluate its relevance to synaptic homeostasis and functions. Results Among candidates with known implications in synaptic modulations, BCL2-associated athanogene-3 (BAG3) ranked the highest. CDK5-mediated phosphorylation on Ser297/Ser291 (Mouse/Human) destabilized BAG3. Loss of BAG3 unleashed the selective protein degradative function of the HSP70 machinery. In neurons, this resulted in enhanced degradation of a number of glutamatergic synaptic proteins. Conditional neuronal knockout of Bag3 in vivo led to impairment of learning and memory functions. In human AD and related-mouse models, aberrant CDK5-mediated loss of BAG3 yielded similar effects on synaptic homeostasis. Detrimental effects of BAG3 loss on learning and memory functions were confirmed in these mice, and such were reversed by ectopic BAG3 re-expression. Conclusions Our results highlight that neuronal CDK5-BAG3-HSP70 signaling axis plays a critical role in modulating synaptic homeostasis. Dysregulation of the signaling pathway directly contributes to synaptic dysfunction and AD pathogenesis.This work was supported by the National Science Foundation in China (Grant: 31571055, 81522016, 81271421 to J.Z.; 81801337 to L.L; 81774377 and 81373999 to L.W.); Fundamental Research Funds for the Central Universities of China-Xiamen University (Grant: 20720150062, 20720180049 and 20720160075 to J.Z.); Fundamental Research Funds for Fujian Province University Leading Talents (Grant JAT170003 to L.L); Hong Kong Research Grants Council (HKUST12/CRF/13G, GRF660813, GRF16101315, AoE/M-05/12 to K.H.; GRF16103317, GRF16100718 and GRF16100219 to H.-M,C.); Offices of Provost, VPRG and Dean of Science, HKUST (VPRGO12SC02 to K.H.); Chinese University of Hong Kong (CUHK) Improvement on Competitiveness in Hiring New Faculty Funding Scheme (Ref. 133), CUHK Faculty Startup Fund and Alzheimer’s Association Research Fellowship (AARF-17-531566) to H.-M, C. 该研究受到了国家自然科学基金、厦门大学校长基金、福建省卫生教育联合攻关基金等的资助

    InP基光子集成发射芯片的研究

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    Tel4掺杂量对n型Bi2Te3基烧结材料热电性能的影响

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    采用区熔法结合放电等离子体快速烧结(SPS)技术制备了n型Bi2Te3基热电材料.在300-500K的温度范围内测量了各热电性能参数,包括电导率(σ)、塞贝克系数(α)和热导率(к),研究了掺杂剂TeI4的含量(质量百分比分别为0,0.05,0.08,0.10,0.13和0.15wt%)对热电性能的影响.结果表明:试样的载流子浓度(n)随TeI4含量增加而增大,使电导率增大、塞贝克系数的绝对值先增大而后减小,从而导致品质因子(α2σ)呈先增加后降低的变化趋势;同时,由于异质离子(I-)以及载流子对声子的散射作用增强,可显著降低其晶格热导率.烧结材料的性能优值(zT=α2σ/к)对应于TeI4含量为0.08wt%有其最大值,约为0.92.此外,烧结材料的抗弯强度增加至80MPa左右,从而可以显著改善材料的可加工性以及元器件的使用可靠性

    一种碲化铋基热电材料的制备方法

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    本发明公开了一种碲化铋基热电材料的制备方法。它通过控制机械合金化和SPS过程中的各项工艺参数,维持粉体材料的大小在一定尺寸范围,利用SPS技术快速致密化的特点,使得烧结块体材料的晶粒不发生长大现象,从而在维持电学性能基本不变的基础上降低材料的热导率,最终同时改善材料的热电性能和力学性能,进而使所制备材料的利用率获得了显著提高,同时极大改善热电器件的稳定性与可靠性。本发明采用机械合金化结合放电等离子烧结技术制备碲化铋基热电材料,省略了商业化生产中缓慢而且需要精确控制的区熔生长过程

    一种碲化铋基热电材料的制备工艺

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    本发明公开了一种区熔生长结合热压法制备碲化铋基热电材料的工艺,其特征在于将晶体材料进行粉碎与过筛,以获得具有一定粒度分布的初始粉体材料,然后在热压炉中对粉料进行烧结,利用热压法制备相应的块体材料。由它制备的碲化铋(Bi2Te3)基热电材料具有良好的晶粒取向性与力学性能。该工艺通过控制材料的显微结构即晶粒取向性,在维持热电性能的基础上大幅度改善了其力学性能,使材料的利用率、可加工性、以及元器件的稳定性与可靠性等均得以大大提高。该工艺所需要的设备成本低,就设备价格而言,相同产能的热压设备只是SPS设备的十分之一,制备过程简单,从而具有良好的产业化前景

    一种In-Se基热电材料的制备方法

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    本发明公开了一种In-Se基热电材料的制备方法,该方法首先采用熔炼法合成In-Se材料,得到元素分布均匀的In-Se化合物,然后采用区熔生长法,通过优化熔融温度、熔区宽度、生长速度等工艺参数,制备具有良好晶粒取向性的In-Se基大块多晶材料。与现有的熔炼、球磨结合热压或放电等离子烧结制备工艺相比,本发明的制备方法能够得到晶粒取向性好、热电性能高的In-Se基热电材料,同时能够缩短制备时间、降低能耗
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