中国能源资源开发利用布局与国土资源节约集约耦合关系

本文主要以我国东部、东北部、中部和西部为研究对象,从能源资源潜力、能源勘探开发现状、能源资源开发利用布局等方面,探究能源资源开发利用和国土资源节约集约之间的耦合关系,并提出相关建议,这将对我国走结构优化、节约集约、效率提升的绿色发展新路具有一定的参考价值。     

Mechanism of CeO_2 synthesized by thermal decomposition of Ce-MOF and its performance of benzene catalytic combustion

In this paper,the formation mechanism of mesoporous CeO_2 synthesized by thermal decomposition of Ce-MOF and its performance of benzene catalytic combustion,as well as the structure-activity relationship between them were studied in depth.The self-assembly process and physicochemical properties of CeO_2 were characterized by thermogravimetry analysis,powder X-ray diffraction,N_2 adsorption/desorption,high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy techniques.Characterization results show that Ce-MOF is completely decomposed into pure mesoporous CeO_2 when the decomposition temperature is higher than 400℃.At this threshold temperature,CeO_2(400) has the largest specific surface area and pore volume of 114 m~2/g and 0.152 cm3/g,respectively.CeO_2(400) exhibits very high catalytic activity for benzene combustion,which can completely catalyze the degradation of benzene at 260℃.Meanwhile,the mesoporous CeO_2(400) supported Pt nanocrystalline catalysts were prepared by high temperature solution-phase reduction method.Pt/CeO_2(400)can completely degrade benzene at about 200℃ and represents high durability and good waterresistance for benzene combustion during 100 h of continuous reaction.     

LaO_x(OH)_y supported platinum catalysts for CO oxidation:Deactivation by formation of lanthanum carbonate

Platinum catalyst for CO oxidation has been studied for decades,due to its high activity and good stability.In this work,we prepared three different lantha num oxide or hydroxide supports(LaO_x(OH)_y),and deposited platinum(Pt) with 0.5 at% via an impregnation approach to synthesize Pt/LaO_x(OH)_y catalysts.However,we find that these catalysts perform a poor stability for the CO oxidation reaction.The fresh and used samples were comprehensively characterized by multiple techniques including power X-ray diffraction(XRD),X-ray absorption fine structure(XAFS),transmission electron microscopy(TEM),temperature-programmed reduction by carbon monoxide(CO-TPR) and thermogravimetric analysis(TGA),to demonstrate that the oxidized platinum atoms or clusters,without any component of Pt-Pt metallic bond,are highly dispersed on the surface of LaO_x(OH)_y.Furthermore,the as-formed lanthanum carbonate(La₂O₂CO₃) during the exposure to ambient circumstances or in the reaction atmosphere of CO+O₂,severely impair the reactivity of Pt/LaO_x(OH)_y.On the basis of the obtained experimental results,we have drawn a conclusion that the oxidized P_tO_x atoms or PtxOy clusters are the active species for CO oxidation,while the formation of lanthanum carbonate is the origin of deactivation on reactivity.     

基于 SNA 的政府投资项目非正式关系治理研究

以关系网络为视角研究非正式关系对政府投资项目治理的作用。基于社会网络分析法,通过对政府投资项目正式关系与非正式关系网络对比分析,确定了非正式关系网络的核心区域与主要参与方的影响力指数。结果表明,项目经理、副经理和政府主管部门副职领导构成非正式关系“三角核心区域”,政府主管部门副职领导与项目经理是“信息枢纽”。非正式关系有助于提高参与方协同效率,但亦存在转化为非法合谋关系的可能性,针对政府投资项目治理在强调正式关系的同时应纳入对非正式关系的考量     

Antecedents of behavioural commitment in inter-organizational relationships: a field study of the UK construction industry

Commitment is vital in inter-organizational relationships. It is important to understand what drives commitment which then affects the relationship between organizations. Commitment is a multidimensional construct and its dimensions can be broadly categorized into attitudinal and behavioural perspectives. In conventional practice, commitment researchers have tended to focus on the attitudinal perspective, while the behavioural perspective is largely ignored. In an attempt to buck that conventional trend commitment research is proposed along the unconventional but widely accepted as important behavioural perspective, building up a more complete understanding of the importance of behavioural commitment, as well as developing and validating a theoretical model that depicts precisely the relationship between behavioural commitment and its key driving factors. Accordingly a large-scale questionnaire survey has been conducted in the UK construction industry and 636 responses were collected. Structural equation modelling was then used to test the theoretical model. Results validate trust, reliance and dependence as the major antecedents of behavioural commitment. A new direction in commitment research adds new findings to the current body of commitment literature.     

黏砂变形GFRP筋与约束混凝土之间的黏结性能

基于30个Losberg拉拔试验,对黏砂变形GFRP筋与采用箍筋约束的混凝土之间的黏结性能进行了较为系统的研究.研究表明:GFRP筋与约束混凝土之间的黏结-滑移(τ-s)曲线可分为微滑移段、滑移段、下降段、二次上升段以及残余下降段;对于采用箍筋约束的GFRP筋试件,均只发生拔出破坏,而对于无箍筋约束的GFRP筋试件,其破坏模式包括拔出和劈裂两种;与无箍筋约束的GFRP筋试件相比,GFRP筋与约束混凝土之间的黏结强度增加了0％～16％,而达到黏结强度时对应的滑移量则提高了1.20～2.76倍.在考虑GFRP筋直径、黏结长度、体积配箍率等因素的基础上,建立了GFRP筋与约束混凝土之间的黏结-滑移本构模型.     

锈蚀槽钢梁荷载-挠度关系研究

对锈蚀槽钢梁荷载-挠度关系曲线进行研究。试验研究表明:试件剪跨比和高跨比对锈蚀槽钢梁的荷载-挠度关系曲线有较大影响。锈蚀槽钢梁的荷载-挠度关系曲线可以分为2个阶段:第一阶段为弹性段,其斜率与剪跨比有关;第二阶段为屈服强化段,其斜率与第一阶段基本呈线性关系。在试验研究基础上,提出锈蚀槽钢梁承载力和挠度的计算方法,建立槽钢梁荷载-挠度关系曲线计算模型。该模型形式简单,便于工程实际应用。     

试论工程监理与工程项目管理的关系

随着我国工程建设的不断发展,工程监理也逐渐向着工程项目管理的方向转变,工程项目管理将会进一步提升整个项目建设的经济效益和社会效益,成为当前工程管理发展的新方向。本文就工程监理与工程项目管理的关系进行了相关的探讨和分析。     

Knowledge contribution in information system development teams: An empirical research from a social cognitive perspective

The extent of knowledge contribution is the key to the success of system development projects. Knowledge contribution refers to the knowledge that is provided to increase a team's efficiency and achieve its goal. This study proposes a research model exploring factors that influence the extent of knowledge contribution from a social cognitive perspective. These factors include the team relationship commitment, team relationship norms, and awareness of expertise location. Additionally, this study argues that a team's awareness of expertise location mediates the effects of affective commitment and relationship norms on knowledge contribution. The result shows that the awareness of expertise location plays a crucial mediating role in the relationships between the two socially prescribed motivations and knowledge contribution. Moreover, team relationship commitment has an important impact on team established relational norms.     

权力关系变迁中武汉都市区簇群式空间的形成机理

随着城市区域化及区域城市化态势的日益显现,一些大城市受到各种条件的影响,在都市区尺度上形成一种簇群状空间形态,武汉表现得较为典型。本文试图从权力关系变迁入手分析武汉簇群式空间的形成机理。地方各级政府间的博弈使外围区政府采用"双城"模式发展,加上在都市区空间各个方向发展较为均等的条件下,各区政府纷纷与资本结盟各自为政发展,使都市区外围空间均衡镶嵌,武汉都市区空间被"簇化"。若武汉内外环境没有较大的变动,武汉簇群式的空间态势仍会继续下去。