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1.
采用密度泛函理论(Density Function Theory,DFT)中的B3LYP和B3PW91方法,在LanL2DZ赝势基组水平上对Ptn^0,±(n=2-4)团簇的几何构型和稳定性进行了研究,主要从振动频率、能级、解离能3个方面进行了分析.研究表明:铂三聚物的中性、阴离子和阳离子最稳定结构都为等腰三角形;四聚物的中性、阴离子的最稳定结构都是二面体,阳离子则是正四面体结构最稳定.所计算的结果都与实验值相符合.  相似文献   

2.
采用密度泛函理论(Density Function Theory,DFT)中的B3LYP和B3PW91方法,在LanL2DZ赝势基组水平上对Ptn^0,±(n=2-4)团簇的几何构型和稳定性进行了研究,主要从振动频率、能级、解离能3个方面进行了分析.研究表明:铂三聚物的中性、阴离子和阳离子最稳定结构都为等腰三角形;四聚物的中性、阴离子的最稳定结构都是二面体,阳离子则是正四面体结构最稳定.所计算的结果都与实验值相符合.  相似文献   

3.
通过一种有效的构建三维M/S/Cu配位聚合物的方法,成功合成了一个新的基于鞍状单体[ MoS4 Cu4]的阴阳离子穿插的三维配位聚合物{[MoS4Cu4(4,4′-bpy)4][MoS4Cu4(4,4′-bpy)2I4·4H2O]}n.X射线单晶衍射表明,该晶体属于四方晶系,空间群为I41/acd,a=24.830(3)?,b=24.830(3)?,c=28.208(6)?,α=β=γ=90°.晶体结构分析显示,配位聚合物1由穿插的阳离子[MoS4Cu4(4,4′-bpy)4]2+和阴离子[MoS4Cu4(4,4′-bpy)2I4·4H2O]2-组成的三维钻石状配位聚合物.  相似文献   

4.
以A1(NO3)3·9H2O、Nd(NO3)3·6H2O、Y(NO3)3·6H2O和NH4HCO3为原料,采用共沉淀法制备出纯相的Nd:YAG纳米粉体。借助FT-IR、TG/DTA、XRD等测试手段对前驱体和Nd:YAG纳米粉体进行了表征,根据表征结果,推断了合成机理与成相机理。研究结果表明:合成过程中Y和Al元素按照3:5的比例均匀沉淀下来,形成包裹型结构的前驱体4[Al(OH)3]·6[Al(OH)CO3]·3[Y2(CO3)3·3H2O]·3.74H2O,煅烧时无定型的前驱体经由六方结构和钙钛矿结构的YAlO3(YAP),在1000℃直接转变为立方结构的Nd:YAG纳米粉体,晶粒大小20nm左右。  相似文献   

5.
CO2电化学还原合成甲酸的研究   总被引:1,自引:0,他引:1  
研究了电解液中的阳、阴离子以及KHCO3浓度对CO2合成甲酸电流效率的影响,并分析了反应的初始物种.结果表明,在含有不同阳、阴离子的电解液中.甲酸电流效率的高低顺序为K >Na >Li >NH 4和PO3-4相似文献   

6.
江南造船公司,近期为武汉航运公司建造一艘3000m2LPG运输船。该船总长94.77m,垂线间长8800m,型宽15.60m,型深5.60m,设计吃水3.6m,载重量3133t,液化气罐容积1500m2,定员18人。航行于内河A、B级航区。具球形倾倾斜船艏,方艉,钢板结构流线型悬挂舵。主要装载乙烯(C2H4)、乙烷(C2H6)、丙烷(C3H8)、丁烯(C4H8)、无水氨(NH3)等。江南承造3000m~3LPG运输船@陈鸿毅  相似文献   

7.
采用密度泛函理论DFT(Density Functional Theory)的B3LYP杂化密度泛函和广义梯度近似泛函GGA(Generalized Gradient Approximation)中的PW91泛函,在双ξ价基组LANL2DZ水平上对Irn^0,±(n=2~4)几何结构进行全面优化,并对基态构型的电子结构、振动频率和能量等进行了系统的理论分析.结果表明,Irn^0,±(n=2~4)团簇的稳定构型都是平面的,基态中性团簇中三聚物Ir3团簇的能隙最大,电子结构最稳定,四聚物Ir4团簇的结合能最大,热力学稳定性最好.  相似文献   

8.
介绍了以MCN(M=Na,K)和K3[M’(CN)6](M’=Fe,Co)为氰基来源的氰基桥联配合物溶剂热合成的研究进展。讨论了影响溶剂热合成氰基桥联合物的主要因素,如:反应条件、有机配体、氰基来源、平衡离子、溶剂种类及摩尔比等.最后指出了目前存在的问题,并对今后的研究趋势进行了展望.  相似文献   

9.
磷光铱配合物因其稳定的化学结构、可调的磷光波长和发射寿命一直成为发光领域的研究热点.文中将吡啶取代的氮嵌入的二氧桥多元环单元设计成环金属主配体L1,又以2-嘧啶苯并咪唑作为环金属辅助配体L2,最终设计合成了一种新型的氮嵌入混配型磷光铱配合物Ir1.研究结果表明,该配合物在溶液(λem=586 nm)和薄膜(λem=577 nm)中均展现出明显的橙红色磷光发射,且在薄膜中展现出较长的发光寿命(τ=6 885 ns).理论计算表明,配合物Ir1的最低激发三线态(T1)是由HOMO-1→LUMO+1轨道的跃迁为主导的,并且展现出明显的电荷从配体(L1)与配体(L2)之间的跃迁(3LLCT),配体(L1)自身的电荷从氮嵌入二氧桥单元到吡啶单元的跃迁(3ILCT).此外,由于该氮嵌入多元环单元强的π供电子特性,配合物Ir1的T1还表现为特殊的的配体(L1)到金属铱中心的电荷跃迁(3LMCT).  相似文献   

10.
采用密度泛函理论(DFT)中的B3LYP方法,在6—311+G和Lanl2dz基组下研究了V2^0,+团簇的平衡几何结构、稳定性以及光谱性质。计算结果表明,团簇V2^0,+的基态构型都是D+H对称。阴离子和阳离子的多重度都为4,中性的为3和5。计算的总能量、结合能、键长和文献符合得很好;电离能和实验值相吻合。得到了团簇结构的稳定性信息,比较T6—311+G和Lank2dz两种基组对团簇的适应性所表现出的差异。  相似文献   

11.
Errata     
正In the paper"Influence of Fouling Assemblage on the Corrosion Behaviour of Mild Steel in the Coastal Waters of The Gulf of Mannar,India"in Vol.12,No.4,Page:509,References were lost,and the two authors’biographies were identical.The correct text is shown below.We apologize to the authors and our readers for any inconvenience caused by the errors.  相似文献   

12.
13.
正St.John's,Newfoundland,Canada,May 31-June 5,2015 OMAE2015 is the ideal forum for researchers,engineers,managers,technicians and students from the scientific and industrial communities from around the world to: meet and present advances in technology and its scientific support;  相似文献   

14.
联合作战计划和执行系统   总被引:2,自引:1,他引:1  
全球指挥控制系统(GCCS)实施当前美国海军网络中心战信息基础设施的联合计划网络。联合作战计划和执行系统(JOPES)支持GCCS实现联合计划。JOPES有两类计划:时间不限的精密预案计划生成作战计划、方案计划或职能计划;时间敏感的危机行动计划生成作战命令或战役方案。前者在和平时期创建的作战计划是后者的计划基础,加速应付危机的能力。  相似文献   

15.
In terms of equal sailing distances, where is the inflexion when ships depart from ports in the Asian Continent to New York via Suez and/or Panama?
The answer is China South Port Group (Hong Kong, Shenzhen and Guangzhou).  相似文献   

16.
Recent measurements of wave induced hull strain and flexure in RN warships are presented together with the derivation of the current design criteria for extreme hull girder bending loads. The history of the development of the shipboard instrumentation used is given and recent developments to improve the quality and ease of analysis of the data are described. An unexpectedly high transverse asymmetry in the longitudinal strains measured in destroyers is shown to be the result of a combination of vertical and lateral bending in oblique seas. Finally recent theoretical comparisons between the loading of Deep-Vee hulls and conventional UK rounded bilge hulls are presented which demonstrate the higher loading experienced by this type of hull form.  相似文献   

17.
桥梁防撞设施物理模型试验   总被引:1,自引:0,他引:1  
物理模型试验是预报防撞设施所受撞击力及优化设计方案的主要方法之一。结合杭州湾大桥柔性防撞设施及东海大桥独立式防撞体设计方案,阐述了船—防撞体撞击试验的基本原理、方法、试验方案及相关试验结果。提出了柔性防撞系统的优化方案。试验结果表明,该方案经济有效,可供预报类似桥梁防撞设施撞击力时参考。  相似文献   

18.
詹明  郑厅厅 《港工技术》2010,47(4):17-19,23
印尼某电厂项目码头水工建筑物包括码头、防波堤和护岸等主要组成部分。在该项目水工建筑物的设计过程中,综合考虑当地的自然条件、施工能力和材料来源等因素,不断优化结构选型和结构断面。根据不同使用要求,护岸分别采用直立式和斜坡式2种结构型式,推荐的设计方案节省投资、施工方便,可供同类工程设计参考。  相似文献   

19.
Despite the many socio-economic similarities between Sweden and Norway, differences in jurisdiction, organisation, cooperation, and financing of long-distance passenger train and coach services have led to the development of four distinctively different ways of serving the markets. This paper describes how the train and coach markets have developed in the two countries, with emphasis on regulatory and industrial structure and a couple of performance variables.Looking at passenger rail, both countries separated infrastructure from operation over a decade ago. However, while Norwegian rail is characterised by an almost monopoly supplier, rail services in Sweden are partly decentralised to the responsibility of county authorities and are widely subjected to competitive tendering. The rest of the network is about to be opened up for on-the-track competition. Swedish Rail (SJ) has spent the last decades consolidating its core business (passenger rail) and sold out its other businesses. In contrast, the Norwegian state rail (NSB) has expanded its business to become a major bus operator and property owner, with extensions also into the Swedish market.The coach industry was more recently deregulated in both countries. The Swedish coach market is dominated by privately owned companies operating services to and from Stockholm. In Norway, state-owned NSB is a major coach operator on medium distance routes, and is also the largest partner of Nor-Way Bussekspress which totally dominates long-distance coach services. Further, the Norwegian coach market is characterised by cross-ownership and cooperation which has enabled an extensive route network which covers most of Norway.We find distinct differences in achievements in the two modes and in the two countries. Swedish rail services have succeeded in winning market shares and in renewing and developing both infrastructure and service levels to a greater extent than the Norwegian model. On the other hand, the Norwegian coach market seems to be more developed and efficient compared to its Swedish counterpart.The paper concludes with a discussion on the possible links between the different approaches and the performance observed, with the aim to stimulate further and more detailed research on some important issues.  相似文献   

20.
开放式数据挖掘系统模型   总被引:2,自引:0,他引:2  
目前国内已经出现了少量的数据挖掘相关产品。国内数据挖掘软件无论从数量还是质量上比较,都与国外软件存在着较大的差距。随着数据仓库技术的普及,数据挖掘应用的需求越来越强烈,如何缩短这种差距,研发数据挖掘软件产品成为国内业界的一个重要问题。通过引用目前国际通用数据挖掘标准技术来构建开放式的数据挖掘系统模型,该系统模型从可扩展性、可重用性、易用性等方面得到了加强。  相似文献   

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