锐钛矿TiO（101）表面电子能带结构的理论研究

二氧化钛作为一种理想的光催化和光电转换半导体材料,受到了广泛的关注和研究,其表面的电子能带结构作为其本征的化学性质之一,决定着表面上氧化还原反应发生的可能性.对二氧化钛表面电子能带结构进行深入研究对于我们从微观上认识并改良二氧化钛这一光电催化材料,以及进一步开发利用更好的光催化材料都具有非常好的指导意义.本论文采用密度泛函理论,计算研究了锐钛矿TiO（101）表面的电子能带结构,并通过与金红石TiO（110）晶面的对比,系统分析了两个表面电子能带结构的不同以及水分子的溶剂化作用对电子能带结构的影响.国家自然科学基金项目(No.21373166)资助

铝先生的诊疗

自铝第一次被化学家发现并在实验室制备至今,铝一直与人类如影随形,铝及其化合物在生产和生活中有着重要的应用。本文将铝拟人化,以\"诊疗\"的形式,采用对话体,回顾了铝的发现史和应用史。国家基础科学人才培养基金(J1310024

硫的自述

硫,无论是元素还是化合物,都在人类的生活与生产中起着至关重要的作用。本文将硫元素拟人化,介绍了其发展史,在地球上的分布、性质以及在生活中的应用,让读者在趣味阅读中了解硫及其化合物。“化学学科拔尖学生培养试验计划”学生科研能力培养探

Structure analysis of anode flow field of micro direct methanol fuel cell based on Fluent

微型直接甲醇燃料电池中阳极流场结构对电池的性能有着重要的影响。为了合理设计阳极流场结构,改善甲醇燃料在阳极流场中的分布,采用计算流体动力学(Cfd)软件fluEnT对微型直接甲醇燃料电池进行建模并仿真分析。分析比较了点型、平行和蛇形3种不同流场图案下得到的压降与流速分布,得出蛇形流场能够更有利于甲醇燃料的均匀分配。在此基础上分别建立不同流道宽度(800,400,200,100μM)的蛇形流场模型,通过仿真计算甲醇燃料的分布情况来分析其对燃料电池性能的影响,并结合实验结果进行对比得出流道宽度为200~400μM之间为优化值。Structure of anode flow field is very important for micro direct methanol fuel cell.To optimize the structure of the anode flow field and the distribution of methanol in it,a model of micro direct methanol fuel cell is created and analyzed by using the computational fluid dynamics(CFD) software.The influence of flow field shapes of grid,parallel and serpentine are analyzed and the pressure drop and velocity distribution in the three kinds of flow fields are studied.It shows that the flow field of serpentine is the best for the even distribution of fuel.Based on this,serpentine flow field models with different width(800,400,200 and 100 μm) are created.Simulations are taken to analyze the influence of distribution to cell performance and compared with experimental results,it shows that the optimal value of flow channel width is 200 ~400 μm.国家自然科学基金重点资助项目(60936003

Dynamic Evolution of Regional Ecological Services Based on TM Remote Sensing

针对传统评估区域生态系统服务价值空间异质性的问题,本研究将TM遥感影像与价值评估法相结合,测算出针对研究区域的当量因子表,并建立了只需遥感影像数据即可快速并较为精准地动态计算区域生态系统服务价值的多元回归模型。文章以北京市永定河、厦门市和青海省不同尺度为例,对该方法评估区域生态系统服务价值的可行性和准确性进行了讨论,以期为生态综合管理提供定量化参考依据。This paper discussed the dynamic evaluating of regional ecological services with remote sensing technique,based on the comprehensive analysis the character of indexes method and currently equivalent method applying to regional ecological services.With the established method in the literature,it discussed the practical possibility for evaluation the temporal and special regional ecological services in Yongding River,Xiamen and Qinghai province.Compared with the traditional static indexes evaluation,our method discussed the possibility of dynamically evolutional evaluation,in order to provide reference of ecosystem management.北京市科学技术委员会“永定河生态修复目标体系研究”(D090409004009003);北京市生态学重点学科项

CDK5-dependent BAG3 degradation modulates synaptic protein turnover

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

A theoretical Study of Proton and Electron Transfer at the Anatase TiO2(101)/H2O Interface

二氧化钛作为一种理想的光催化和光电转换半导体材料，受到了广泛的关注和研究，然而光催化效率低下的问题一直限制着其在光催化制氢、光催化降解、太阳能电池等方面的大规模推广。而从理论模拟的角度，对二氧化钛进行深入研究，能够帮助我们从微观上认识并改良这一光电催化材料，同时对于我们进一步开发利用更好的光催化材料也具有非常好的指导意义。固/液界面作为光催化和光电转换等化学反应发生的核心区域，一直是理论化学研究者们关注的焦点，然而，由于其极端复杂，也一直是理论模拟的一大难点问题。基于以上问题，本论文主要使用我们课题组近年来发展的采用基于密度泛函理论的分子动力学模拟（DFTMD）与自由能微扰理论（FEP）相结合...As one of the most commonly-used materials for photocatalysis and solar energy conversion, titanium dioxide (TiO2) has been extensively studied for more than 40 years. However, the microscopic understanding of the photocatalytic process is still largely lacking. In this thesis, we studied the anatase TiO2/H2O interface using a recently developed computational method. The method combines Density Fu...学位：理学硕士院系专业：化学化工学院_物理化学学号：2052013115165

Aligning Electronic Energy Levels on the Anatase TiO_2(101) Surface

二氧化钛作为一种理想的光催化和光电转换半导体材料,受到了广泛的关注和研究,其表面的电子能带结构作为其本征的化学性质之一,决定着表面上氧化还原反应; 发生的可能性. 对二氧化钛表面电子能带结构进行深入研究对于我们从微观上认识并改良二氧化钛这一光电催化材料,; 以及进一步开发利用更好的光催化材料都具有非常好的指导意义.; 本论文采用密度泛函理论,计算研究了锐钛矿TiO_2(101)表面的电子能带结构,并通过与金红石TiO_2(110)晶面的对比,系统分析了两个表面; 电子能带结构的不同以及水分子的溶剂化作用对电子能带结构的影响.As one of the most commonly-used materials for photocatalysis and solar; energy conversion, titanium dioxide (TiO_2) has been extensively studied; for more than 40 years. Its photoelectrochemical activity crucially; depends on the band positions at the interface. In this work, the; valence band maximum (VBM) and conduction band minimum (CBM) of a model; TiO_2 surface are com puted using the standard work function method at; the level of Perdew-Burke-Ernzerhof (PBE) density functional, which are; then converted to the scale of the standard hydrogen electrode (SHE) by; subtracting the absolute SHE potential. Comparing with the rutile TiO_2; (110) surface, we find a similar upshift in the VBM and CBM upon the; adsorption of water molecules on the anatase TiO_2(101) surface, and the; band gap error intrinsic to the PBE functional can be mainly; attributable to mis-positioning of the VBM. In addition, in contrast to; the finding on the rutile TiO_2(110) surface that the adsorption of 1; monolayer water largely recovers the band alignment of the aqueous; interface, our preliminary calculations indicate that on the anatase; TiO_2(101) surface there is a considerable difference between the; simplified model with the adsorption of 1 monolayer water and the fully; solvated interface, suggesting the necessity to include the water; molecules beyond the first adsorption layer in order to realistically; represent the anatase TiO_2 water interface.国家自然科学基金项