S-苯基-S-甲基-N-甲酰基亚砜亚胺化合物的合成

针对目前N-甲酰基亚砜亚胺的合成需要复杂的步骤以及昂贵的反应试剂,文中以S-苯基-S-甲基-NH亚砜亚胺与(溴二氟甲基)三甲基硅烷(TMSCF2Br)为原料,通过改变反应条件,成功地将亚砜亚胺的氮氢键转化为氮碳键,进而简单、高效地合成了S-苯基-S-甲基-N-甲酰基亚砜亚胺.用柱色谱法对反应产物进行分离,并用核磁共振氢谱(1HNMR)、碳谱(13CNMR)、高分辨质谱(HRMS)等对产物进行表征.结果表明,最佳的反应条件为N,N-二甲基甲酰胺(DMF)作溶剂、不需要碱源、25℃下反应30 min,S-苯基-S-甲基-N-甲酰基亚砜亚胺的产率可达55%.该法具有原料易得、步骤简单、条件温和、绿色环保等优点.     

二正丁基亚砜与水杨酸对硝酸钕的协同萃取

有机亚砜(R_2SO)具有与路易士酸配位的能力,多碳亚砜水溶性小有些又可从石油副产物中获得,所以它们作为萃取剂在无机物溶剂萃取方面受到重视。关于二正丁基亚砜(DBSO)和一酸性螯合剂对三价稀土的协同萃取作用,顾翼东对HPZL体系的实验说明DBSO的协萃能力大于TBP;可是D.Dyrssen和J.H.Augustson等对HTTA体系的研究结果表明DBSO的协萃作用明显地弱于TBP。同时,Dyrssen的工作还说明在HTTA体系中DBSO和三价稀土形成的萃合物与TBP所形成的类型相同。有关TBP在水杨酸(H_2SaL)体系中对三价稀土的协同效应已有报导,并确认形成M(HSaL)_3(TBP)_2类型萃合物。为了进一步了解有机亚砜的协萃作用,本     

二(2-乙基己基)亚砜萃取分离钯铂

本文研究了二(2-乙基己基)亚砜萃取剂对盐酸体系中钯、铂的萃取性能。结果表明:在适当的酸度下使用该萃取剂能达到钯、铂定量萃取和分离的目的;它对钯的萃取饱和容量很高;且加入象N_(1923),N_(263)等添加剂后不仅可使萃取加速进行,而且还可进一步提高萃取率;以硫脲作为反萃剂可使萃取剂反复使用,实验证明,二(2-乙基己基)亚砜的煤油溶液具有良好的再生性能。     

二丁基亚砜-磷酸-水三元体系的液液相平衡研究

二丁基亚砜为萃取磷酸的良好溶剂。本文对二丁基亚砜-磷酸-水三元体系在40℃的液液相平衡关系进行了研究,测定了互溶席曲线,联结线及褶点。并将结果与正丁醇-磷酸-水体系进行了比较和讨论。     

正十二烷硫基乙酸对钯的萃取

本世纪六十年代以来,硫醚及亚砜作为一类新型的萃取剂己越来越为人们所重视,并且随着对硫醚及亚砜萃取金属离子性能研究的深入,从单功能团的硫醚或亚砜转向复合官能团的含硫化合物及其氧化物。我们合成了正十二烷硫基乙酸 C_(12)H_(25)SCH_2-COOH(n—laurylthio acetic acid),用它的甲苯溶液对钯进行了液液萃取,测得了该萃取剂对钯具有良好的萃取性能。     

二正戊基亚砜在硝酸溶液中萃取铀、钍和稀土的研究

用二正戊基亚砜的甲苯溶液在硝酸溶液中对铀、钍和一些稀土元素进行了萃取研究。结果表明,稀土元素,即使与铀、钍同时存在于水相中,在0—10M硝酸中,也不被萃取。在所研究的情况中,二戊基亚砜对铀的萃取大大优于对钍的萃取,这使它们的分离成为可能。     

高氯酸铕、六氟磷酸铕二苯亚砜及苯丁基亚砜配合物的荧光光谱

合成了高氯酸铕二苯亚砜Ｅｕ（ＤＰＳＯ）７（ＣｌＯ４）３以及六氟磷酸铕二苯亚砜Ｅｕ（ＤＰＳＯ）７·（ＰＦ６）３及高氯酸铕苯丁基亚砜Ｅｕ（ＰＢＳＯ）７·（ＣｌＯ４）３配合物．从配合物的荧光激发和发射光谱可以看出：Ｅｕ３＋的发光系配体亚砜敏化所致．二苯亚砜配合物的发光强度高于苯丁基亚砜配合物．５Ｄ０→７Ｆ２谱带在二苯亚砜配合物中发生劈裂，且强度高于５Ｄ０→７Ｆ１，这表明Ｅｕ３＋在二苯亚砜配合物中所处格位对称性较低而在苯丁基亚砜配合物中所处格位对称性较高．     

不对称亚砜萃取和S-烷基异硫脲盐反萃金(Ⅲ)的研究

研究了用正-丁基辛基亚砜萃取、S-丁基异硫脲盐反萃金(Ⅲ)的行为.实验结果表明萃合物的组成为H_3O(n-BOSO)_3AuCl_4,反萃金(Ⅲ)是离子交换机理,金(Ⅲ)萃合物用元素分析、热分析、摩尔电导、UV和IR光谱进行了表征。     

用两相滴定法研究ABB’三元协萃剂对铕（Ⅲ）的协同萃取

本文在黎乐民、徐光宪教授工作的基础上，根据两相体系的物料及电荷平衡原理，进一步导出用A-B-B’三元混合萃取剂协同萃取金属离子的计算公式，并用两种不同的滴定液进行滴定，测定了PM1Bn．P(1-苯基-3-甲基-4-异丁酰基吡唑啉酮-5)与DASO(二戊基亚砜)及TBPO(三丁基氧化礴对铕(I)的协同萃取,     

用两相滴定法研究ABB′三元协萃剂对铕(Ⅲ)的协同萃取

本文在黎乐民、徐光宪教授工作的基础上,根据两相体系的物料及电荷千衡原理,进一步导出用A-B-B′三元混合萃取剂协同萃取金属离子的计算公式,并用两种不同的滴定液进行滴定,测定了PM_iB_uP(1-苯基-3-甲基-4-异丁酰基吡唑啉酮-5)与DASO(二戊基亚砜)及TBPO(三丁基氧化磷对铕(Ⅲ)的协同萃取,所测得的三元协萃常数1g乩_(311)在误差范围内一致。.     

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.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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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.     

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     

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。