Study on Becoming Effective of the Contract

内容摘要合同生效问题是合同法学基本问题之一，也是民法学重要问题之一。长期以来，我国法学界对于合同效力、合同有效和合同生效这几个紧密关联问题的研究一直都没有停止过，并取得了很多成果，为推动我国的立法、司法事业和学术进步做出了应有的贡献；然而，在这个领域里仍有许多的问题不断引起人们研究的兴趣，引发热烈的讨论。本文试图通过对合同的效力、合同生效的意义、合同生效的标志等问题的分析以及合同生效与合同有效、条件与期限、生效期限与履行期限等概念的比较，说明在当事人之间设立债的关系是合同的效力之一，合同的生效意味着合同在当事人之间产生了合同之债的关系，合同之债的产生是合同生效的标志，并尝试对《合同法》规定的特...Abstract The question of becoming effective of the contract is one of the basic problems in science of the contract law, it is one of the important problems of science of civil law too. In our country, law scholars have been studying about effect of the contract, validity of the contract and becoming effective of the contract constantly, and have made many achievements to promote the progr...学位：法律硕士院系专业：法学院法律系_法律硕士(JM)学号：20030822

Ternary Alloy Electrocatalysts for Oxygen Reduction Reaction

质子交换膜燃料电池作为重要的电化学能源转换装置,在提高能量转换效率、减少环境污染等方面具有诱人的前景.然而,阴极氧还原过电位较大、活性较低、稳定性差,且铂基催化剂昂贵,使该燃料电池难以商业化.纳米结构电催化剂的发展有望解决此难题.对纳米合金电催化剂其组分和结构的设计是开发高活性、高稳定性和低成本的燃料电池电催化剂的重要因素.本文综述了近期由分子设计和热化学控制处理法制备的三元纳米合金电催化剂对燃料电池氧还原反应催化性能的最新进展.该方法可控制纳米合金的尺寸、组成以及二元和三元纳米催化剂的合金化程度.以高活性的三元纳米合金催化剂PTnICO/C为例,综述了在设计燃料电池电催化剂时结构和组成的纳米级调优的重要性.PTnICO/C电催化剂的质量比活性远高于其二元合金催化剂和PT/C商业电催化剂.三元电催化剂的催化活性可通过控制其组成来调节.本文还讨论了三元纳米合金催化剂的结构及其协同效应对增强其电催化性能的影响.Proton exchange membrane fuel cell represents an important electrochemical energy conversion device with many attractive features in terms of efficiency of energy conversion and minimization of environmental pollution.However,the large overpotential for oxygen reduction reaction at the cathode and the low activity,poor durability and high cost of platinum-based catalysts in the fuel cells constitute a focal point of major barriers to the commercialization of fuel cells.The development of nanostructured catalysts shows promises to addresses some of the challenging problems.The ability to engineer the composition and nanostructure of nanoalloy catalysts is important for developing active,robust and low-cost catalysts for fuel cell applications.This article highlights some of the recent insights into the catalytic properties of ternary nanoalloy catalysts prepared by molecularly-engineered synthesis and thermochemically-controlled processing,focusing on oxygen reduction reaction in fuel cells.This approach has demonstrated the abilities to control size,composition,and nanoscale alloying of binary and ternary nanoalloys.A highly-active ternary nanoalloy catalyst consisting of platinum,nickel and cobalt that is supported on carbon(PtNiCo/C) will be discussed as an example,highlighting the importance of nanoscale tuning of structures and composition for the design of fuel cell catalysts.The mass activity of selected PtNiCo/C catalysts has been shown much higher electrocatalytic activity than those observed for their binary counterparts and commercial Pt/C catalysts.Selected examples will also be shown that the catalytic activity can be tuned by the ternary composition.The structural and synergistic properties of the ternary nanoalloy catalysts for the enhancement of the electrocatalytic activity will also be discussed.supportedbyNationalScienceFoundation(CBET-0709113andCHE-0848701);DepartmentofEnergy;Honda;andUTCPowe

Ternary Alloy Electrocatalysts for Oxygen Reduction Reaction

质子交换膜燃料电池作为重要的电化学能源转换装置，在提高能量转换效率、减少环境污染等方面具有诱人的前景.然而，阴极氧还原过电位较大、活性较低、稳定性差，且铂基催化剂昂贵，使该燃料电池难以商业化.纳米结构电催化剂的发展有望解决此难题。对纳米合金电催化剂其组分和结构的设计是开发高活性、高稳定性和低成本的燃料电池电催化剂的重要因素.本文综述了近期由分子设计和热化学控制处理法制备的三元纳米合金电催化剂对燃料电池氧还原反应催化性能的最新进展.该方法可控制纳米合金的尺寸、组成以及二元和三元纳米催化剂的合金化程度.以高活性的三元纳米合金催化剂PtNiCo/C为例，综述了在设计燃料电池电催化剂时结构和组成的纳米级调优的重要性.PtNiCo/C电催化剂的质量比活性远高于其二元合金催化剂和Pt/C商业电催化剂.三元电催化剂的催化活性可通过控制其组成来调节.文章还讨论了三元纳米合金催化剂的结构及其协同效应对增强其电催化性能的影响.Proton exchange membrane fuel cell represents an important electrochemical energy conversion device with many attractive features in terms of efficiency of energy conversion and minimization of environmental pollution. However, the large overpotential for oxygen reduction reaction at the cathode and the low activity, poor durability and high cost of platinum-based catalysts in the fuel cells constitute a focal point of major barriers to the commercialization of fuel cells. The development of nanostructured catalysts shows promises to addresses some of the challenging problems. The ability to engineer the composition and nanostructure of nanoalloy catalysts is important for developing active, robust and low-cost catalysts for fuel cell applications. This article highlights some of the recent insights into the catalytic properties of ternary nanoalloy catalysts prepared by molecularly-engineered synthesis and thermochemically-controlled processing, focusing on oxygen reduction reaction in fuel cells. This approach has demonstrated the abilities to control size, composition, and nanoscale alloying of binary and ternary nanoalloys. A highly-active ternary nanoalloy catalyst consisting of platinum, nickel and cobalt that is supported on carbon (PtNiCo/C) will be discussed as an example, highlighting the importance of nanoscale tuning of structures and composition for the design of fuel cell catalysts. The mass activity of selected PtNiCo/C catalysts has been shown much higher electrocatalytic activity than those observed for their binary counterparts and commercial Pt/C catalysts. Selected examples will also be shown that the catalytic activity can be tuned by the ternary composition. The structural and synergistic properties of the ternary nanoalloy catalysts for the enhancement of the electrocatalytic activity will also be discussed.The research work was supported by National Science Foundation (NSF) and Department of Energy (DOE).The research work was supported by National Science Foundation (NSF) and Department of Energy (DOE).作者联系地址：1. 纽约州立大学宾汉姆顿分校化学系，美国 纽约13902；2. 厦门大学化学化工学院， 福建 厦门361005Author's Address: 1. Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, USA 2. College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China通讯作者E-mail：[email protected]

Characterization of CeO_2-LnO_(1.5) Solid Solutions and Their Behavior in Catalytic Combustion of Methane

向CEO2中引入ln3+离子后形成的CEO2-lnO1.5（ln=lA，nd，SM，gd）固溶体（n（CE）：n（ln）=1：1）是一种无贵金属的新型高效甲烷燃烧催化剂.比表面、Xrd、rAMAn、TEM等分析证实，这类固溶体具有部分畸变的萤石结构，ln3+进入晶格后诱发的结构变化使得团溶体的表面和本体能同时参与氧化还原反应.实验表明，该固态溶液体系是甲烷催化燃烧的良好催化剂.A series of ceria-lanthanide oxide CeO2-LnO1.5 (Ln=La, Nd, Sm, Gd) solu solutions were prepared in n(Ce): n(Ln) ratio of 1: 1 by coprecipitation method.Their partlydistorted Fluorite structures were revealed by speciFic surFace, XRD, Raman spectrum andTEM results.The structure change of the solid solution due to the entering of Ln3+ ions intoCeO2 lattice could make both the surFace and bulk of the solid solution participate in the redox reaction simultaneously.The solid solutions were Found to be highly active For catalyticcombustion of methane

西藏黑颈鹤越冬期昼间行为的时间分配

采用瞬时扫描取样法研究了西藏南部黑颈鹤越冬行为的时间分配和活动节律。结果表明,取食是黑颈鹤冬季的最主要行为,占其日活动时间的73.0%,其次,警戒行为占14.0%,行走行为占5.6%,保养行为占4.5%,静息行为占1.7%,社群行为仅为0.4%。黑颈鹤的全天活动表现出明显的节律性变化,在9:00～11:00和17:00～18:00分别出现一个取食高峰,而在13:00～16:00则出现一个休息高峰和取食低谷。不同群体结构黑颈鹤在不同越冬时期,全天活动中各种行为的时间分配存在一定的差异,这样的差异也存在于家庭鹤的成鹤与幼鹤之间

T形头单向螺栓连接T形组件抗拉性能研究

新型T形头单向螺栓能够有效解决传统高强螺栓无法直接应用于钢梁-钢管柱栓接节点的问题。然而，采用此类新型螺栓连接的梁柱节点中各组件承载机理尚不明确，有待进一步探索。T形头单向螺栓连接节点的特征在于端板及钢管柱壁上具有栓孔形状。为探索此类新型连接节点中端板及钢梁组件的力学响应与承载机理，文章基于组件法，通过有限元分析软件ABAQUS对T形件节点的抗拉性能展开了系统的数值分析。主要研究内容和结论如下：建立了精确的节点三维有限元模型，研究了T形头单向螺栓连接T形件节点中翼缘出现的5种典型屈服线模式，并开展了广泛的参数分析。最后基于虚功原理及屈服线理论，给出T形头单向螺栓连接T形件节点的屈服承载力计算公式

STUDY of ULTRAFINE CUBIC Ce_(0.5)Zr_(0.5)O_2 SOLID SOLUTION

以共沉淀法制备CE-zr-O固溶体,在液相反应阶段、干燥阶段和灼烧阶段分别采取快速喷射和加入表面活性剂、正丁醇共沸蒸馏脱水以及选择适当的灼烧温度等手段控制团聚体的生成.制得超细颗粒CE_(0.5)zr_(0.5)O_2固溶体.Xrd,TEM及比表面积等的测试结果表明,该催化剂是面心立方结构、较高比表面的超细颗粒.zr--(4+)掺杂较均匀的超细固溶体,其rAMAn光谱中晶格畸变带来的T_(2g)活性振动模式分裂谱峰较弱,说明晶体结构规整性较大.催化甲烷燃烧的活性测试结果也证实超细颗粒CE_(0.5)zr_(0.5)O_2固溶体的催化活性大于常规共沉淀法制备的催化剂.Ce-Zr-O solid solution was prepared by coprecipitation with control of agglomeration.Ce4+ and Zr4+ mixed solution was spurted into the precipitant of surfactant added in the stage of reaction of liquid phase.After elimination of water by means of heterogeneous azeotropic distillation process with n-butanol,the powder was calcined at different temperatures.The result mixed oxide is face-centered cubic analyzed by XRD.The solid solutions are fiberlike ultrafine particles from TEM pictures.The super-micro particles have larger specific surface than the particles prepared by common coprecipitation.In the Raman spectra,splitting peaks of t2g active vibration mode resulted by distorted lattice are weaker than the samples prepared by common coprecipitation process.Raman spec-troscopic research show that the crystal structure of the ultrafine solid solution has better degree of order and Zr4+ ion enters into the lattice more even.Super-micro powder of Ce0.5Zr0.5O2 solid solution is more active to catalyze the combustion of methane than the catalyst synthesized by common coprecipitation method

PREPARATION of La_2O-3-ZrO_2 OXIDE COMBUSTIONAL CATALYST WITH DEFECTIVE FLUORITE STRUCTURE

缺陷萤石型lA_2Q_3-zrO_2固溶体的催化燃烧活性受制备条件的影响,本文通过对其共沉淀前体的表面结构和热分解过程的分析,发现共沸蒸馏的办法可以有效地控制前体表面羟基的缩合过程,减少团聚,保持前体中金属离子均匀分散,为生成缺陷有序的烧绿石型的lA_2zr_2O_7复氧化物提供了可能,复合氧化物固溶体的表面阳离子配置情况与样品的催化氧化性能密切相关,软团聚前体的烧结产物对甲烷燃烧反应具有更高的催化活性。One of the most important factors which affect the catalytic performances of complex oxide used in catalytic combustion is the preparative process of samples.Combined with several spectrum techniques, the study on the thermal decomposing procedure of the coprecipated precursors illustrates that the catalytic activity of La2O3-ZrO2 composite oxide solid solution is intimately concerned with drying condition, due to the different crystallization therein.The codistillation involved n-butanol could keep the uniform distribution of metal cations in precursor intact, and facilitates acquiring the well-crystallized sample by following thermal treatment.These crystalline with regular lattice will supply more anion defects on the surface, which act as the active sites for the complete oxidation of hydrocarbon