藜蒿挥发油化学成分研究

采用水蒸气蒸馏法提取洞庭湖区野生藜蒿挥发油,用GC-MS法测定其化学成分和质量分数,其馏出物共鉴定出48种化合物,主要有:α-丁香烯(15.734%)、丁香烯(13.246%)、1-甲基-1-乙烯基-2-(1-甲基乙烯基)-4-(1-甲基亚乙烯基)-环己烷(9.511%)、(E)-7,11-二甲基-3-亚甲基-1,6,10-十二碳三烯(5.267%)、八氢-4a,8a-二甲基-7-(1-甲乙基)-1(2H)-萘酮(4.184%)、Z,E-2,13-十八碳二烯-1-醇(4.126%)、α-没药醇(2.950%)、(1S-内)-乙酸-1,7,7-三甲基双环[2.2.1]-2-己酯(2.845%)、吉马烯D(2.803%)等.     

L—2（10）—蒎烯四醋酸铅氧化产生扩环产物的结构

在四醋酸铅氧化L-2(10)-蒎烯的产物中,首次分离得到三种扩环产物2、3、4,经HR-MS、EI-MS、NMR(~1H、~(13)C、H-H COSY、H-C COSY)、IR等波谱方法确定,分别为(1S,6S)-7,7-二甲基双环[4.1.1]-3-辛烷酮及其异构体(1R,6S)-7,7-二甲基双环[4.1.1]-2-辛烷酮和(4S)-4-异丙烯基环庚烷酮,文中还讨论了反应机理。     

双环[2.2.1]庚-5-烯-2-羧酸乙酯衍生物的合成与表征

以混合碳五和丙烯酰氯为起始原料合成了双环[2.2.1]庚-5-烯-2-甲酰氯,然后经吡啶催化分别与1-甲基环己醇、1-甲基环戊醇和2-乙基-2-金刚烷醇反应合成了1-甲基环己基双环[2.2.1]庚-5-烯-2-羧酸乙酯、1-甲基环戊基双环[2.2.1]庚-5-烯-2-羧酸乙酯和2-乙基金刚烷-2-基双环[2.2.1]庚-5-烯-2-羧酸乙酯等.通过MS和HNMR表征了目标产物结构.     

吉安杉木碎屑精油的化学成分分析研究

采用常压水蒸汽蒸馏法提取了吉安县杉木加工过程中产生的碎屑精油,该精油具有典型的木香香气,其中得油率为1.0%~1.5%.用GC-MS法对该油进行了定性定量分析,在分出的65个色谱峰中共鉴定出49种化合物,占精油总量的92.8%,其中含有柏木醇(39.98%)、α-柏木烯(10.17%)、雪松烯(5.59%)、乙酸柏木酯(3.35%)、5-(7a-异丙烯基-4,5-二甲基八氢化茚-4-基)-3-甲基-2-戊烯-1-醇(3.22%)、[s-(E,E)]-1-甲基-5-亚甲基-8-异丙基-1,6-环癸二烯(2.97%)、杜松醇等.     

云木香挥发油化学成分的研究

目的:对云木香挥发油进行化学成分的研究,为云木香的进一步开发和利用提供科学依据.方法:采用水蒸气蒸馏法从云木香中提取挥发油,用气相色谱-质谱法对化学成分进行分析,以归一化法计算各个化学成分的相对含量.结果:共分离出140个峰,鉴定了其中56个化学成分,占挥发油总油量的83.29%.结论:云木香挥发油中的主要成分为(Z,Z,Z)-9,12,15-十八碳三烯-1-醇(20.07%)、1,2,3,3a,4,5,6,7-八氢-1,4-二甲基-7-(1-甲基乙烯基)-[1R-(1α,3aβ,4α,7β)]-薁(10.04%)、石竹烯(6.69%)、3a,4,6a,7,8,9,9a,9b-八氢-6-甲基-3,9-二亚甲基-[3aS-(3aα,6aα,9aα,9bβ)]-奥[4,5-b]呋喃-2(3H)-酮(6.37%).     

新疆产黄花蒿挥发油成分研究

采用水蒸汽蒸馏法提取，运用毛细管气相色谱．质谱联用法对新疆产黄花蒿(Artemisia annua L.)挥发性化学成分进行了分析，用气相色谱面积归一化法测定了各成分的相对百分含量，经毛细管色谱分离出48个峰，并鉴定出峰所对应的化合物，其主要化学成分为2，5-二氢-3-甲基呋喃(68．48％)；β—月桂烯(10．13％)；1R，3Z，9S-4，11，11-三甲基-8-亚甲基二环[7，2，0]-3-十一碳烯(7．74％)；7，11-二甲基-3-亚甲基-1，6，10-十二碳三烯(2．42％)；桉油醇(1．68％)；圣亚麻三烯(1．52％)等，为进一步开发利用提供了科学依据。     

花梨木挥发油化学成分的分析

采用毛细管气相色谱-质谱(CGC-MS)联用技术对花梨木挥发油的化学成分进行研究,经毛细管气相色谱分离出29个组分,共确认了其中的24种成分,占总油量的96.9%.其主要成分是2,4二甲基-2,4-庚二烯醛、3,7,11-三甲基-1,6,10-十二碳三烯-3-醇、2-蒈烯-4-醇、2-(5-甲基呋喃-2-基)-丙酸乙醛、反式-2-甲基-5-(1-甲基乙烯基)-2-环己烯-1-醇等.     

大野芋花香气成分分析及其综合开发应用前景

采用固相微萃取(SPME)-气相色谱/质谱(GC/MS)联用技术分析大野芋花的挥发性成分,共鉴定出12种挥发性化合物,其中含量较高的是2-异丙基-5-甲基茴香醚(46.88%),二氢-β-紫罗兰酮(39.80%),苯甲酸甲酯(6.61%),以上三种占鉴定总成分的93.29%.其中10种主要挥发性物质有香味,按花味分类,4-蒈烯、二氢-β-紫罗兰酮、4-(2,6,6-三甲基-环己烯-1-乙基)-2-丁醇、β-紫罗兰酮属紫罗兰花型;苯甲酸甲酯、1,2-二甲氧基苯、水杨酸甲酯、4-羟基-3-甲基苯乙酮(或称香草酮)、2-异丙基-5-甲基茴香醚、肉桂酸甲酯属芳香花型.可见,大野芋可作为良好的香料植物开发利用.     

三产地白术挥发油氧化分解后化学成分的变化

为了比较不同产地白术挥发油氧化分解前后化学成分及含量变化的差异,文章将湖南、安徽、河北产白术挥发油分别置于太阳光下进行氧化分解,产物稳定后,采用GC-MS技术对各产地挥发油氧化分解前后化学成分及其含量变化进行分析比较。结果显示,来自地域、气候和土壤等环境因素不同的湖南、安徽、河北产白术挥发油,经同一条件氧化分解后,虽然新增、消失及含量发生变化的成分有差异,但其氧化分解后18种成分的含量显著变化趋势相一致。其中γ-榄香烯消失,1,2,3,4,4a,5,6,8a-八氢化-4a,8-二甲基-2-(1-甲基乙烯基)萘、1-乙烯基-1-甲基-2-(1-甲基亚乙基)-4-(1-甲基乙烯基)-环己烷和9,10-去氢异长叶烯含量明显降低,尤其是苍术酮降幅平均为97.80%,而其余13种成分含量增幅从大到小依次为β-桉叶醇、白术内酯Ⅲ、17-(1,5-二甲基己基)-10,13-二甲基-2,3,4,7,8,9,10,11,12,13,14,15,16,17-十四氢化-1H-环戊[a]3-菲酚、白术内酯Ⅰ、1-甲氧基-2-(1-甲基-2-亚甲基环戊基)-苯、Isovelleral、β-桉叶烯、4,4a,5,6,7,8-六氢化-4a,5-二甲基-3-(1-甲基亚乙基)-2(3H)-萘、9,12(Z,Z)-十八碳二烯酸、荜澄茄油烯醇、正十六酸、广木香内酯、3-环戊基-6-甲基和3,4-庚二烯-2-酮。     

蚜虫警戒素的合成研究(Ⅰ)

本文报道以柠檬醛为原料合成蚜虫警戒素前体7,11—二甲基—3—亚甲基—6,10碳二烯—1—醇(4)以及中间体6,10—二甲基—1,5,9—十一碳三烯—4—醇(5)。     

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