人工种植红豆杉各部位紫杉醇的提取过程分析

对江西人工种植红豆杉叶、根、枝中紫杉醇的提取纯化技术进行了研究，比较了加热回流与超声加热回流两种提取方法，经过固相萃取、液一液萃取、正己烷沉淀、硅胶柱层析分离纯化紫杉醇，紫外扫描检测叶、根、枝中紫杉醇的含量分别13．89μg/g、12．67μg/g、39．33μg/g，纯度分别为83％、81．7％、90％，说明红豆杉植物的枝比较适合做为提取紫杉醇的原料，并且超声加热回流法优于普通加热回流法．     

三种海洋微藻抗肿瘤活性的研究

利用不同的溶剂提取紫球藻、小球藻、等鞭金藻胞内和胞外产物，采用MTT（Methylthiazoly pheny-tetrazolium bromide）比色法检测胞内外产物对HeLa和K562肿瘤细胞活性的影响，以筛选和研究其中的抗肿瘤活性物质。结果表明：紫球藻胞外水相和破碎后上清液经石油醚：乙酸乙酯（V：V=1：1）的萃取物、小球藻破碎后上清液经乙酸乙酯、正己烷：环己烷（V：V=1：1）、三氯甲烷、甲醇：甲苯（V：V=1：1）、石油醚的萃取物和等鞭金藻破碎后上清液经石油醚、乙醚、正已烷、乙醇的萃取物都有明显的抑制肿瘤细胞的效果，显示了从海洋生物微藻中开发新的抗肿瘤药物的潜力。     

气相色谱法检测农药残留中预处理技术的进展

本文就气相色谱法测定农药残留量过程中的固相萃取（SPE）、固相微萃取（SPME）、超临界流体萃取（sFE）等预处理技术作了简要的介绍．并简述了近年来了几种常见农药GC色谱检测时预处理技术的最新研究和应用情况，供从事农药残留量分析的检测与研究人员参考。     

土茯苓所含有机磷农药分析中SPE与LLE的比较

就土苻苓中4种有机磷农药的分析对比了SPE（固相萃取）与LLE（液液萃取）两种预处理技术,并对影响SPE的相关因数进行了条件优化．结果表明,优化后的SPE不仅在相同的浓度范围内有更好的线性关系,而且降低了检出下限,在准确度、精密度方面也与LLE相当．因此,用SPE—GC—FPD方法代替传统LLE检测土茯苓中有机磷农药是可行的．     

山药及其同属植物参薯中多酚含量的测定

采用Folin-Denis（FD）法和普鲁士蓝（PB）法测定山药及其同属植物参薯80％醇提物的氯仿相、乙酸乙酯相、正丁醇相中多酚含量．两种方法均显示：不同产地山药样品中，正丁醇相中多酚含量较高，乙酸乙酯相中次之，氯仿相中多酚含量最低．利用薄层层析（TLC）、紫外光谱（UV）、显色反应及^13C核磁共振（NMR）技术对各极性段萃取物进行定性检测分析，发现在氯仿和乙酸乙酯萃取部分均检测出酚性成分的存在，而在正丁醇相定性检测时，未检出酚性成分的存在．该法简便易行、重现性好、准确度高，可用于山药及其同属植物参薯中多酚含量的测定．     

CO2超临界萃取芝麻油中芝麻素含量的GC-MS测定

本文研究CO_2超临界萃取芝麻油中芝麻素含量的GC-MS测定。萃取芝麻油的最佳条件为：萃取压力32MPa、萃取温度50℃、萃取时间2h,此时萃取率达到48．5％；提取芝麻紊的最佳条件为：萃取时间3h、萃取温度60℃、料液比2．5∶1(V/V)、静止分液时间3h；最后用GC-MS技术对芝麻索进行定性和定量分析。     

超临界CO2流体萃取法提取紫杉醇的研究

利用超临界CO2流体萃取法从红豆杉枝叶中提取分离紫杉醇，用反相高效液相色谱法(HPLC)测定萃取物中的紫杉醇含量，并用液质联用(LC／MS/MS)进行产物鉴定．结果表明，粒径为0．25—0.45mm的红豆杉枝叶在27．6MPa，31℃下，以甲醇为修饰剂和吸收液进行萃取时，在120min内可使紫杉醇萃取完全，萃取率达96．7％，萃取物中紫杉醇纯度可达到1％以上．与传统的乙醇三次提取方法相比，超临界流体萃取法流程简单，步骤少，耗时短，无废渣溶剂残留，是一种环境友好的提取方法．     

提取水中氟喹诺酮类药物残留物方法研究

设计一种利用中空纤维支撑液膜萃取技术（HF-SLM）从自来水中提取四种氟喹诺酮类抗生素（氧氟沙星、依诺沙星、恩诺沙星、诺氟沙星）的简单方法：支撑液膜萃取的最适条件为：供体pH=7,受体HCl浓度为0．1mol／L,振荡时间15min,液膜构成为15％的TOPO．     

高效液相色谱法测定样品中紫杉醇的含量

建立了反相高效液相色谱法测定样品中紫杉醇含量的方法。色谱柱采用中国科学院大连化学物理研究所生产的YWQC18柱（4．6X250mm,5μm）,流动相为乙腈：水：三氟乙酸（40：60：0．1）,检测波长227um,紫杉醇浓度在40μg／ml～1400μg／ml内呈解性关系。回收率98．2～99．3％,变异系数0．75～3．39％。     

蔬菜中多种有机氯和拟除虫菊酯农药残留的同时分析方法

运用组合固相萃取（Solid phase extraction，SPE）柱净化、GC-ECD检测建立了6种有机氯和6种拟除虫菊酯农药残留的气相色谱同时分析方法．用乙酸乙酯作溶剂、高速均质和超声波方法辅助萃取样品中的农药残留，萃取液浓缩并转溶于丙酮-正己烷混合溶液（2：8，v／v）中，经过组合SPE柱（由上到下为CARB、SCX、bE）净化，乙酸乙酯定容．选用青花菜进行加标回收率实验，回收率为60％-120％，方法检测限为0．01μg/Kg-0．1μg／Kg．     

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.     

Features of Women''s language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

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