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1.
对Pd原子采用相对论有效原子实势(RECP/SDD),C、O原子采用6-311++G^**基函数,利用B3LYP方法计算了PdCO分子的微观结构以及不同温度下的热力学函数.以气态分子总能量中的振动能EV代替该分子处于固态时的振动能量,以电子运动和振动运动熵SEV代替分子处于固态的熵的近似方法,计算了不同温度下金属Pd与CO反应的两种可能产物Pd-CO(s)和Pd-OC(s)的ΔH^Θ、ΔS^Θ、ΔG^Θ及反应平衡压力,导出了反应平衡压力与温度的关系,证实CO吸附以C端接近Pd.比较Pd-CO(s)、PdH2(s)和PdN2(s)的Gibbs自由能ΔG^Θ,可得到在常压及298.15-898.15K温度条件下,吸附平衡压力pCOKp(H2)〉Kp(N2),由此证实CO较易被金属Pd表面吸附.为了减弱钯合金膜对CO的吸附,提出加外电场改变CO分子的排列方向使O原子接近膜表面的方案.  相似文献   

2.
制备了2-氨基嘧啶(AP)与钴的配合物Co(AP)2Cl2,并对其组成进行了测定.采用具有恒温环境的溶解-反应量热计,分别测定了298.15K时[CoCl2?6H2O(s)+2AP(s)]和Co(AP)2Cl2(s)在100.00mL2mol?L-1HCl溶液中的溶解焓.通过设计热化学循环得到2-氨基嘧啶(AP)和氯化钴反应的反应焓?rHmΘ=48.81±0.61kJ.mol-1,进而计算出配合物Co(AP)2Cl2在298.15K时的标准摩尔生成焓为?fHmΘ[Co(AP)2Cl2,s,298.15K]=–443.41±3.46kJ.mol-1.  相似文献   

3.
对钯和钇原子采用SDD基组,氢原子采用6-311++G**全电子基函数,利用B3LYP方法,得到了Pd3YH分子的基态具有C3V对称性,基态能量为-422.7675a.u..采用朱正和研究小组提出的气固反应热力学函数的近似计算方法,得到了Pd3Y合金吸氢反应1/2H2(g)+Pd3Y(s)=Pd3YH(s)在温度范围298.15~998.15K内Pd3YH(s)的生成热力学函数和Pd3Y合金氢化反应平衡压力.比较Pd3YH(s)、PdH(s)、PbPdH(s)和PdYH(s)的ΔGQ的大小,得到ΔGQPdH(s)ΔGQPbPdH(s)ΔGPQd3YH(s)ΔGPQdYH(s),这说明Pd3Y合金比PbPd合金和纯Pd对H2的吸附能力强,但比PdY合金要弱.  相似文献   

4.
目的制备三元配合物[Nd(C9H7O2)3(C12H8N2)]·H2O,并计算出其ΔfHΘm。方法在甲醇和无水乙醇溶液中由六水氯化钕、1,10-邻菲罗啉以及肉桂酸反应合成[Nd(C9H7O2)3(C12H8N2)]·H2O,并采用红外光谱对其表征。依照热力学原理和Hess定律设计热化学循环。在298.15K及常压下,利用恒温环境的微量热计测定六水氯化钕、1,10-邻菲罗啉、肉桂酸以及三元配合物在混合溶剂(体积比0.5mol/L HClO4∶DMF∶乙醇∶水=1.5∶2.0∶1.0∶1.0)中的溶解焓。结果与结论设计下列配位反应的热化学循环:NdCl3·6H2O(s)+3C9H8O2(s)+C12H8N2·H2O(s)=[Nd(C9H7O2)3(C12H8N2)]·H2O(s)+3HCl(l)+6H2O,求得了三元配合物[Nd(C9H7O2)3(C12H8N2)·H2O(s)]的标准摩尔生成焓:ΔfHΘm[[Nd(C9H7O2)3(C12H8N2)]·H2O(s),298.15K]=1 933.522±0.402kJ·mol-1。  相似文献   

5.
硝酸铽与丙氨酸配位反应的热化学研究   总被引:1,自引:1,他引:0  
采用具有恒温环境的反应量热计,以溶解量热法,分别测定了298.15 K 时[Tb(NO3)3·6H2O(s)+4Ala(s)]和配合物Tb(Ala)4(NO3)3·H2O(s)在2 mol·L-1 HCl 溶液中的溶解焓.通过设计的热化学循环,可计算得到六水硝酸铽和丙氨酸配位反应的反应焓ΔrHθm(298.15 K)=28.727 kJ·mol-1,并计算出配合物 Tb(Ala)4(NO3)3·H2O(s) 在298.15 K 时的标准生成焓ΔfHθm(298.15 K)=-3 847.0 kJ·mol-1.测定了Tb(Ala)4(NO3)3·H2O(s)在水中的溶解焓,计算出配离子Tb(Ala)3+4(aq) 在298.15 K时的标准生成焓ΔfHθm[Tb(Ala) 3+4,aq,298.15 K]=-2 973.5 kJ·mol-1.  相似文献   

6.
PbPd合金氢化反应分析   总被引:1,自引:1,他引:0  
采用B3LYP方法,对钯和铅原子采用LANL2DZ收缩价基组,氢原子采用6-311++G**全电子基函数,得到了气态PbPd、PbPdH及H2分子的能量E、焓H和熵S.对于气固氢化反应1/2H2(g)+PbPd(s)=PbPdH(s),采用朱正和研究小组提出的气固反应热力学函数的近似计算方法,得到298.15~998.15 K温度范围内PbPdH(s)的生成热力学函数和PbPd合金氢化反应平衡压力,根据单点计算值拟合出反应平衡压力与温度的函数关系为logpH2=3.00-1.51×103/T.比较PbPdH(s)、PdH(s)和PdYH(s)的△Gθ的大小,得到△GθPdYH(s)△GθPbPdH(s)△GθPdH(s),这说明PbPd合金对H2的吸附能力比纯Pd要强,但比PdY合金要弱,因此在纯Pd中加入Y比加入Pb更有利于提高渗氢速率.  相似文献   

7.
应用具有恒温环境的反应量热计,分别测定了[GdCl3·6H2O(s)+3Gly(s)](Gly代表甘氨酸)和配合物Gd(Gly)3Cl3·3H2O(s)在2mol·L-1HCl溶液中的溶解焓.根据盖斯定律设计一个热化学循环,可计算得到六水氯化钆和甘氨酸配位反应的反应焓ΔrHmθ(298.15K)=-9.471kJ·mol-1,并估算出配合物Gd(Gly)3Cl3·3H2O(s)在298.15K时的标准生成焓ΔfHmθ(298.15K)=-3629.67kJ·mol-1.  相似文献   

8.
利用等温滴定微量热法(ITC)、紫外吸收光谱法(UV)和圆二色谱法(CD)研究了亚叶酸钙(CaFL)与牛血清白蛋白(BSA)在缓冲溶液中的结合反应.热力学结果表明,BSA大分子上存在可结合FL2-阴离子的两类位点.当药物分子与二类结合位点相结合时,标准吉布斯自由能(ΔG°1和ΔG°2)的变化几乎是一样的,然而,标准焓变ΔH°1和ΔH°2分别是(29.76±0.50)kJ.mol-1和(-15.76±0.03)kJ.mol-1.第一类结合是熵驱动过程,而第二类结合则是以熵效应为主的熵焓协同驱动过程.光谱试验结果用于研究BSA-药物超分子体系在溶液中的结构,并且有利于理解热力学数据.  相似文献   

9.
用Rb2CO3(或Cs2CO3)与NTO(3-硝基-1,2,4三唑-5酮,C2N4O3H2)的水溶液混合制备Rb(NTO)·H2O,Cs(NTO)·H2O.用量热法测定了在298.15 K时M(NTO)·H2O(M=Rb,Cs)在水中的溶解焓.(NTO)·H2O和Cs(NTO)·H2O的标准生成焓分别是(-587.57±2.12) kJ·mol-1和(-596.92±2.11) kJ·mol-1.还分别计算了它们的晶格能、晶格焓、脱水生成焓[(RbNTO,cr)是551.46、546.96、-428.33 kJ·mol-1,(CsNTO,cr)是526.31、521.31、-432.35 kJ·mol-1].计算得到Rb(NTO)·H2O和Cs(NTO)·H2O的标准脱水焓分别为(126.57±2.12)kJ·mol-1和(124.26±2.1)kJ·mol-1.并讨论了碱金属的NTO盐的生成焓之间的关系:从Li →K 的标准生成焓随离子半径增加而增大,但从K →Cs ,虽离子半径增加但标准生成焓几乎不变.  相似文献   

10.
异极矿的标准生成热力学函数   总被引:1,自引:0,他引:1  
采用PE公司的Diamond差式扫描量热仪(DSC)测定异极矿脱去1个水分子所生成的产物Zn4Si2O7(OH)2和异极矿Zn4Si2O7(OH)2·H2O在363~563 K温度范围内的恒压比热容;测定恒压条件下,在573.15~998.15 K温度范围内异极矿加热脱水过程的DSC曲线。将比热容换算成摩尔热容,用最小二乘法分别拟合Zn4Si2O7(OH)2和Zn4Si2O7(OH)2·H2O的摩尔热容与温度的函数关系式;利用相关物质的已知热力学参数,设计热力学循环,计算在标准压强和温度298.15 K时Zn4Si2O7(OH)2和Zn4Si2O7(OH)2·H2O的标准生成热力学函数ΔfHmΘ,ΔfSmΘ和ΔfGmΘ。  相似文献   

11.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

14.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

15.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

16.
17.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

18.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

19.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

20.
Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.  相似文献   

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