计算机模拟环甘油磷脂结构及其开环反应机理研究

利用Chem Office软件模拟环甘油替加氟磷脂缀合物的稳定构像的三维立体模型,模型显示1,3,2-二氧磷杂戊烷的端碳原子具有较少的空间位阻.在室温及KOH存在下,对甲苯硫酚能有效地与环甘油替加氟磷脂缀合物反应.通过比较反应物和产物31 PNMR,13CNMR及DEPT,得出了开环反应是发生在五元环的端碳原子上.     

从L-丝氨酸合成新型旋光活性环状磷脂的替加氟(Tegafur)和尿苷缀合物

从Ｌ－丝氨酸出发,经酯化、环磷酰化、磷酰化、加硫等步骤得到替加氟、尿苷硫代环磷酰胺酯缀合物２、３．Ｌ－丝氨酸酯经Ｎ－烷基化,然后再与磷酰二氯关环,进一步与替加氟乙醇反应得到环磷脂缀合物４．考察了两种环磷酰化反应中碳手性中心对磷原子的不对称诱导效果,并用硅胶柱层析分离了产物２、３、４ 的非对映异构体．基于ＮＭＲ数据,对它们的构型进行了讨论和初步的确定,它们的抗癌活性正在测试当中．     

邻苯二甲酰亚胺乙氧基环甘油硫代磷脂缀合物的合成

以碘活化的六乙基亚磷酰三胺为磷酰化及环化试剂 ,经“一锅法”合成了邻苯二甲酰亚胺乙氧基环甘油硫代磷脂缀合物 ,收率达 90 %左右     

从L—丝氨酸合成新型旋光活性环状磷脂的替加氟（Te …

从Ｌ－丝氨酸出发,经酯化、环磷酰化、磷酰化、加硫等步骤得到替加氟、尿苷硫代环磷酰胺酯缀合物４．考察了两种环磷酰化反应中碳手性中心对磷原子的不对称诱导效果,并用硅胶柱层析分离了产物２、３、４的非对映异构体。基于ＮＭＲ数据,对它们的构型进行了讨论和初步的确定,它们的抗癌活性正在测试当中。     

多硫代碳酸盐的应用研究进展

多硫代碳酸盐主要包括三硫代碳酸盐、四硫代碳酸盐和五硫代碳酸盐等。介绍了多硫代碳酸盐的结构、性质和制备,对多硫代碳酸盐在重金属废水处理、金属矿物浮选和土壤生物污染防治的应用研究现状进行了综述。     

含酰亚胺结构的替加氟衍生物的合成及其抗肿瘤活性

以替加氟为原料,分别与2-氯代乙醇、1,3-二溴丙烷、1,4- 二溴丁烷反应,然后与含酰亚胺结构的氨基酸缩合,合成7个含酰亚胺结构的替加氟衍生物(3～5,7～10). 新化合物采用元素分析、1HNMR、13CNMR、MS进行表征,并进行了CHO、K562和B16体外抗肿瘤活性筛选. 体外抗肿瘤活性测试表明:部分替加氟衍生物的抗肿瘤活性较替加氟有所提高.     

卤代磷杂硫烯酮及其相关分子的量子化学计算研究

使用量子化学 ab initio计算方法(RHF)、密度泛函法(B3LYP)和 MP2 法,在 6 311++G(d,p)和AUG CC PVTZ基组水平下,对氟代磷杂硫烯酮、氯代磷杂硫烯酮及其相关分子进行了全优化几何构型的量子化学计算.计算结果表明,氟代和氯代磷杂硫烯酮为累积双烯结构,磷杂硫烯酮的异构体含 C P 三键,所有分子都具有弯曲几何构型.     

几种硫代α—二酮配合物液晶的合成

设计了一种简单的合成路线，合成出３种长链对正烷氧基苯偶酰及相应的双二硫代α－二酮合镍（Ⅱ）配合物，并对苯偶酰的液晶性与对应的二硫代配合物的液晶性进行了研究，初步证实了从具有双重熔化现象的有机分析出发合成具有液晶性质的配合物分子这一设想。     

硫酸介质中二硫代氨基甲酸钠对碳钢的缓蚀机理

为探讨二硫代氨基甲酸钠缓蚀剂在硫酸中对碳钢的缓蚀机理，以胺和CS2为起始反厘物，制备出一系列二硫代氨基甲酸盐类缓蚀剂，进行了红外光谱分析．采用失重法和电化学方法对该缓蚀剂在硫酸中对碳钢的缓蚀作用进行实验．结果表明：二硫代氨基甲酸钠在浓度为0.5mol／L的H2SO4中对碳钢表现出较好的缓蚀性能；在硫酸溶液中，随二硫代氨基甲酸钠缓蚀剂浓度的增加，缓蚀效率相应提高；在H2SO4介质中，二硫代氨基甲酸钠是一个混合型缓蚀剂，氮原子上取代基不同对二硫代氨基甲酸盐类缓蚀剂的缓蚀效率影响较大。     

硫代半缩醛的反应研究

研究了硫代半缩醛与对氟苯基硫脲、氨基脲及辛二胺的反应，产物的结构经红外、核磁、质谱和元素分析得到了证实。     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

A computer generator for randomly layered structures

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

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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海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

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。     

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.     

Exciton Seebeck in Molecular Systems

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     

Achieving Unusual States of Matter Under High Pressure

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