超分子化合物[HN(C_2H_5)_3]_2H[PW_(12)O_(40)]·4H_2O的水热合成、晶体结构及电化学性质

利用中温水热技术合成了新型超分子化合物[HN(C2H5)3]2H[PWl2O40]·4H2O,并采用元素分析、红外光谱、单晶X-射线衍射对其进行了表征.晶体学参数:三斜晶系,C2/C空间群,a=2.468 9(5)nm,b=1.083 1(5)nm,c=2.248 2(5)nm,α=90.00°,β=121.094(5)°,γ=90.00°,V=5.148(3)nm3,Z=4,R1=0.045 6,wR2=0.147 1.该化合物的基本结构单元是由2个质子化的三乙胺分子、4个水分子、1个质子和1个Keggin型杂多阴离子[PWl2O40]3-组成.不同结构单元之间通过氢键作用形成一维链状结构,链间进一步通过分子间氢键构成三维超分子结构.     

一维链状化合物[Cu(C_(10)N_2H_8)_2(H_2O)]_2{[Cu(C_(10)N_2H_8)][Cr(OH)_6Mo_6O_(18)]_2}·10H_2O的合成与晶体结构

在常规条件下,合成了基于Anderson结构多阴离子[Cr(OH)6Mo6O18]3-的一维链状结构化合物[Cu(C10N2H8)2(H2O)]2{[Cu(C10N2H8)][Cr(OH)6Mo6O18]2}.10H2O.通过元素分析、红外光谱和X射线单晶衍射对合成的化合物进行了表征.结果表明:该化合物属于单斜晶系,P21/n空间群;晶胞参数为a=1.4569(2)nm,b=3.4591(5)nm,c=1.5088(2)nm,α=90°,β=111.453(2)°,γ=90°,V=7.0771(18)nm3,Z=4,R1=0.0743,ωR2=0.1916.该化合物是一个一维链状化合物,由交替连接的2,2′-联吡啶铜的配合物和多阴离子[Cr(OH)6Mo6O18]3-组成.相邻链间通过吡啶配体的π-π相互作用,进一步形成了三维结构.     

K5H11[WO2(PW9O34)2]·33H2O和K6Na2H2[Ni4(H2O)2(PW9O34)2]·23H2O的合成与表征

在常规条件下合成了2种具有一维链状结构的多金属钨酸盐K5H11[WO2(PW9O34)2]*33H2O(1)和K6Na2H2[Ni4(H2O)2(PW9O34)2]*23H2O(2).采用X射线单晶结构分析、元素分析和红外光谱对其进行了表征.结果表明:化合物1属于正交晶系,Fddd空间群;晶胞参数a=2.906 3 nm,b=3.179 0 nm,c=3.914 8 nm,α=90.00°,β=90.00°,γ=90.00°,V=36.194 0 nm3,Z=2,R1=0.070 6,ωR2=0.162 1.化合物2属于单斜晶系,P2(1)/ n空间群;晶胞参数a=1.191 6 nm,b=1.654 7 nm,c=2.121 1 nm,α=90.00°,β=100.66°,γ =90.00°,V=4.109 8 nm3,Z=16,R1=0.063 8,ωR2=0.143 2.     

钼磷多金属氧酸盐[Zn(2,2''''-bipy)2]2[PMoⅥ11 MoⅤO40]的合成与晶体结构

利用中温水热技术,成功合成了一种新的过渡金属配合物双支撑的Keggin型钼磷杂多金属氧酸盐[Zn(2,2'-bipy)2]2[PMo11ⅥMoⅤO40],并采用红外光谱、元素分析、单晶X射线衍射等进行了表征.结果表明:标题化合物的基本结构单元是由1个杂多阴离子[PMo11ⅣMoⅤO40]4-和2个[Zn(2,2'一bipy)2]2 片段组成的双支撑构型;不同的结构单元之间通过氢键作用形成一维链状超分子结构;链间进一步通过分子间氢键构成二维层;该晶体属于单斜晶系,P 21/n空间群;晶胞参数α=1.358 7(3)nm,b=1.207 3(2)nm,c=1.893 2(4)nm,α= 90.00°,β=93.15(3)°,γ=90.00β°,V=3.100(9)mn3,Z=2,R1=0.065 8,wR2=0.202 3.     

一维多酸-有机配位聚合物{[Cu(en)2(H2O)][Cu(en)2(H2O)PW3ⅤW9ⅥO40Cu(en)2]·9H2O}n的合成、性质与结构

用水热技术合成了一维锯齿链状多酸-有机配位聚合物{[Cu(en)2(H2O)][Cu(en)2(H2O)-PWⅤ3WⅥ9O40Cu(en)2].9H2O}n,用元素分析、X射线单晶衍射、IR、UV-vis、FS、cv和TG-DTA对其进行了表征.聚合物由有机金属配阳离子[Cu(en)2]2 桥联两个相邻的Keggin结构杂多阴离子[PWV3WV9IO40]6-,构成了一维锯齿链状聚合物.荧光光谱研究发现,标题化合物具有较好的光致发光性.循环伏安测定表明,标题化合物阴离子在pH=1.0的水溶液中存在3步氧化还原过程.TG-DTA结果表明聚合物中杂多阴离子在596.4℃时发生了分解.     

柔性配体构筑两个新的Dawson型超分子化合物的合成、结构以及性能研究

选用两个柔性配体,在水热条件下成功的得到两个新的基于Dawson多酸的超分子化合物,[H_6(L_1)_3(P_2W_(18)O_(62))]_2·5H_2O(1)和[H_6(L_2)_3(P_2W_(18)O_(62))]·3H_2O(2),L_1=1,4-双(5-(4-吡啶基)四唑基)-丁烷,L_2=1,1-双(3,5-二甲基-1H-吡唑基)甲烷.通过红外光谱、元素分析和单晶X-射线对化合物1和2的结构进行了表征.结构分析表明,化合物1的晶胞参数a=42.862,b=15.655,c=29.881(5),α=90°,β=93.72°,γ=90°,V=20008.33,Z=4,R1=0.0565,ωR2=0.1442.化合物2的晶胞参数a=15.020,b=26.347,c=23.177,α=90°,β=106.69°,γ=90°,V=9892(4)3,Z=4,R_1=0.0486,ωR_2=0.1279.化合物1包含两个Dawson多酸阴离子,配体通过氢键环绕在多酸阴离子周围.在化合物2中,配体L_2和Dawson多酸阴离子存在氢键作用拓展成一维超分子链结构,相邻的一维超分子链通过氢键作用形成二维超分子层结构.同时研究了两个化合物的电化学和光催化性质.     

超分子化合物(C_(10)N_2H_(10))_3[TeMo_6O_(24)]·2H_2O的水热合成和晶体结构

利用水热方法合成了一种新的基于多氧阴离子[TeMo6O24]6-的三维超分子化合物(C10N2H10)3[TeMo6O24]·2H2O.通过元素分析、红外光谱、热重分析、X射线衍射对其进行了表征.结果表明:该化合物属于三斜晶系,P-1空间群;晶胞参数a=9.885 9(4) nm,b=10.543 0(5) nm,c=11.131 1(5) nm,α=112.644 0(8)°,β=92.625 0(10) °, γ=90.960 0(9)°,V=1 068.86(8) nm3,Z=1,R1=0.033 3,wR2=0.114 1.在该化合物中,尽管多氧阴离子间不存在直接的相互作用,但是多氧阴离子[TeMo6O24]6-的桥氧和端氧原子具有较高的电荷密度,与质子化的4,4′-联吡啶形成广泛的氢键作用并构筑了高维的超分子网络.晶体结构分析揭示了4,4′-联吡啶分子对晶体的堆积排列起着重要的作用.     

K_5H_(11)[WO_2(PW_9O_(34))_2]·33H_2O和K_6Na_2H_2[Ni_4(H_2O)_2(PW_9O_(34))_2]·23H_2O的合成与表征

在常规条件下合成了2种具有一维链状结构的多金属钨酸盐K5H11[WO2(PW9O34)2].33H2O(1)和K6Na2H2[Ni4(H2O)2(PW9O34)2].23H2O(2).采用X射线单晶结构分析、元素分析和红外光谱对其进行了表征.结果表明:化合物1属于正交晶系,Fddd空间群;晶胞参数a=2.906 3 nm,b=3.179 0 nm,c=3.914 8 nm,α=90.00°,β=90.00°,γ=90.00°,V=36.194 0 nm3,Z=2,R1=0.070 6,ωR2=0.162 1.化合物2属于单斜晶系,P2(1)/n空间群;晶胞参数a=1.191 6 nm,b=1.654 7 nm,c=2.121 1 nm,α=90.00°,β=100.66°,γ=90.00°,V=4.109 8 nm3,Z=16,R1=0.063 8,ωR2=0.143 2.     

以[Nb24O72]24-为构筑块的多铌氧酸盐的合成、结构及性质研究

利用常规水溶液法合成了多铌氧酸盐:[Cu(en)2(H2O)]3[Cu(en)2]0.5[Cu(en)2(H2O)2]0.25{[Cu(en)2][Nb24O72H14.5]}.6.75H2O(en=ethylenediamine)(1),并借助元素分析、IR、UV、XPS、顺磁(EPR)、场诱导表面光电压谱(EFISPS)、热重(TG)和X-射线单晶衍射分析对化合物进行了结构表征和性质研究.结果表明:化合物属三斜晶系,Pi空间群,晶胞参数为:a=1.665 41(5)nm,b=2.228 06(7)nm,c=2.513 80(8)nm,α=89.340 0(10)°,β=73.707 0(10)°,γ=81.972 0(10)°,V=8.861 7(5)nm3,Z=2,R1=0.072 4,wR2=0.197 9.化合物分子包含1个{[Cu(en)2][Nb24O72H14.5]}7.5–阴离子,3个[Cu(en)2(H2O)]2+、0.5个[Cu(en)2]2+和0.25个[Cu(en)2(H2O)2]2+配离子和6.75个结晶水分子.XPS、EPR及价键计算都表明化合物1中所有Cu为+2价,表面光电压谱(SPS)及场诱导表面光电压谱(EFISPS)测试表明化合物1有n-型半导体的特征.     

新型超分子配合物[Cu(Hhbd)(phen)2]·1.5H2O·2CH3OH的合成、晶体结构与表征

利用螯合配体1,10-邻菲咯啉(phen)与羟基丁二酸(H3hbd)及铜盐反应合成了一种新型超分子配合物[Cu(Hhbd)(phen)2].1.5H2O.2CH3OH,通过单晶衍射测定了晶体结构,并用元素分析、红外光谱、热分析等技术对其进行了表征。配合物属三斜晶系,空间群P-1;晶胞参数:a=1.20624(17)nm,b=1.6598(2)nm,c=1.6863(3)nm,α=117.23(9),°β=71.262(3),°γ=117.23(9);°Z=4;最终偏离因子R=0.0420。配合物中每个Cu(Ⅱ)原子与来自两个phen的4个N原子和羟基丁二酸根(Hhbd)的1个O原子配位,形成畸变的三角双锥结构单元。紧邻的单核单元通过phen分子间的π-π堆积作用及Hhbd的羧基O和羟基O与phen环上C原子间的C-H…O氢键的协同作用形成一维zigzag超分子链,毗邻的超分子链籍两种不同氢键相互作用的连接构筑了二维超分子体系。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

英文诗歌中的喻类修辞

为了有助于提高英文爱好者的个人情操、文化素养和学习兴趣,以及专业人员对英语学习和研究进行多途径的探索,本文通过一些精选诗歌的引证和分析,着重论述了喻类修辞法在英文诗歌中的运用其及效果。     

Man Is Unable to Change the Miserable Life——Analysis of the Arrangement of Four Characters in The Glass Menagerie

Tennessee Williams is considered as one of the most important American playwrights since World War II.The Glass Menagerie is his first successful drama,which describes a tragic situation of family and means to say that Man is unable to change the miserable life,no matter whatever means he try,This essay focuses on the analysis of the arrangement of the four main characters:Laura.Amanda,Jim and Tom to reveal the theme.Laura is fragile.Amanda is brave.Jim is vital.Tom is sensible.And all of them develop and try the different means to struggle against life,but fail tragically.With the evidence,the paper comes to conclusion naturally that Man is unable to change the miserable life,and he dooms to fail.     

Characterization of root-nodulating bacteria on Retama raetam in arid Tunisian soils

The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most effective isolate.     

An Affordable Accurate Evaluation of the Binding Conformations Predicted by Molecular Docking Studies in Bio-System

正Recently,docking has been widely used to predict the binding-modes of protein-inhibitors,when the crystal complexes structure was absent.Most docking algorithms are able to generate a large number of probable conformations,it,however,is difficult to effectively evaluate these docking poses and identify the most reasonable bindingmode.In the present study,on the basis of the crystallographic data of human 3-hydroxy-3-methylglutaryl coenzyme     

WIMAX与WI-FI技术分析及联合组网

介绍了WiMAX与Wi-Fi两种无线宽带接入技术,并对两者之间的关系及相互之间的影响做了对比及分析,并对WiMAX的关键技术进行了详细说明,最后对两者的联合组网方式做了简单的探讨。