HPLC法测定不同产地、不同干燥法葛根中主要异黄酮类成分的含量

建立一种高效液相色谱(HPLC)分析方法,测定不同产地、不同干燥方法葛根中葛根素、大豆苷和大豆苷元3种主要异黄酮类成分的含量.选用Symmetry C18色谱柱(4.6 mm×250 mm,5μm),甲醇-水溶液为流动相进行梯度洗脱,紫外检测波长为250 nm.结果表明,不同产地葛根中的葛根素、大豆苷和大豆苷元总含量不...     

泡腾饮品中维生素C的高效液相色谱法测定

建立了一种测定泡腾饮品(大豆异黄酮 VE VC)中VC的高效液相色谱测定方法.该方法采用反相ApolloC18柱,以甲醇/磷酸二氢钾(75/25V/V)作流动相,流速为0.8mL/min,检测波长266nm.结果表明VC在浓度为0.050～0.300mg/mL内有良好的线性关系,线性回归方程为Y=4.78e 007X 6.18e 005(R=0.9991),平均回收率101.78%,标准偏差S=0.001.该方法简便、快速、准确.     

酱油渣中大豆异黄酮的动态逆流提取及分离纯化研究

以酱油渣干粉为原料,对大豆异黄酮提取条件和纯化方法进行研究.采用实验室模拟动态逆流提取酱油渣中异黄酮,并通过正交设计对提取条件进行了优化,确定了最佳提取条件为体积分数为80%乙醇、提取前的浸泡时间12 h、料液比1∶10,总异黄酮提取率可达0.35%,粗提物的纯度为2.01%.选取3种极性不同的大孔树脂填装制备柱,并利用中低压色谱对大豆异黄酮样品进行纯化.结果表明,NKA9大孔树脂对总大豆异黄酮的纯化效果最好,在体积分数为60%乙醇洗脱时,产品纯度可达到32%.该方法能在短时间内对大豆异黄酮样品进行大量的纯化,满足大豆异黄酮产品生产的需要.     

酱油渣中大豆异黄酮动态逆流提取及分离纯化的研究

以酱油渣干粉为原料，对大豆异黄酮提取条件和纯化方法进行研究.采用实验室模拟动态逆流提取酱油渣中异黄酮，并通过正交设计对大豆类黄酮提取条件进行了优化，确定了大豆类黄酮的最佳提取条件为80%乙醇， 提取前的浸泡时间12h，料液比1:10，得到总异黄酮提取率达0.35%，粗提物的纯度为2.01%.选取3种极性不同的大孔树脂填装制备柱，并利用中低压色谱对大豆异黄酮样品进行纯化.结果表明，NKA9大孔树脂对总大豆异黄酮的纯化效果最好，在60%乙醇洗脱时，产品纯度可达到32%.该方法能实施在短时间内对大豆异黄酮样品进行大量的纯化，满足大豆异黄酮产品生产的需要.     

大豆乳清水一级浮渣中大豆异黄酮的薄层扫描检测方法

本文建立了一种针对大豆乳清水一级浮渣粉中大豆异黄酮的薄层层析扫描检测方法.大豆乳清水一级浮渣粉用丙酮一次提取即可将其中的大豆异黄酮全部提取完全,提取方法简单.经薄层层析扫描,大豆乳清水一级浮渣粉中大豆异黄酮的含量为4.505 6 mg/g.检测黄豆黄苷、大豆苷、染料木苷三种苷的薄层板展开剂为二氯甲烷、甲醇和乙酸,黄豆黄素、大豆苷元和染料木素三种苷元的展开剂为氯仿、甲醇和乙酸.建立了大豆异黄酮的标准曲线和方程,并进行了精确性、稳定性检测,其RSD值均小于2%.该方法灵敏、准确、可靠、稳定,是适合大豆乳清水一级浮渣中大豆异黄酮及其异黄酮产品检测的一个完整、快速、省时,实用新方法.     

紫外分光光度法测定豆粕中大豆异黄酮的含量

本文建立一种检测大豆豆粕中大豆异黄酮含量的紫外分光光度分析方法。以染料木素为标准品,在其紫外最大吸收峰260nm处,用紫外分光光度法测定大豆豆粕中异黄酮的含量。回归方程A=0.1676X-0.0118r=0.9982,平均回收率为99.84%,相对标准偏差为1.03%。方法简便、重现性好,使用的试剂毒性小且廉价易得,可作为检测豆粕中异黄酮含量的一种手段。     

不同种类大豆中大豆异黄酮含量及抗氧化性比较

利用液质联用及串联质谱法对黑豆、黄豆及青豆等8个大豆样品进行了大豆异黄酮分析,结果表明:染料木甙(G)及丙二酰基染料木甙(MG)在8个大豆样品中均为主要的大豆异黄酮组分,两者之和平均占到了大豆异黄酮总含量的50%以上;其次为大豆甙(D)和丙二酰基大豆甙(MD),两者之和平均占大豆异黄酮总含量的38%左右;黄豆黄甙(GL)和丙二酰基黄豆黄甙(MGL)则在所有样品中含量均很低,两者之和平均只占总含量的6.8%.这8个样品中,对大粒种样品,黄豆中的大豆异黄酮含量高于黑豆及青豆,而小粒种大豆的异黄酮含量要明显高于大粒种.DPPH和FRAP抗氧化性分析结果则表明,黑豆的抗氧化性高于黄豆及青豆,而小粒种豆的抗氧化性高于大粒种豆.     

大豆异黄酮对大鼠的心肌电生理效应

目的探讨大豆异黄酮对大鼠的心肌电生理效应.方法采用微电极电生理技术观察大豆异黄酮对麻醉大鼠心肌电生理效应.结果大豆异黄酮可缩短大鼠心肌动作电位复极化50%的时间(APD50,P<0.001)及复极化90%的时间(APD90,P<0.01).结论大豆异黄酮可缩短心肌动作电位时程,其机制可能与阻滞钙通道有关.     

高效液相色谱法检测大豆酸乳中微量异黄酮的研究

大豆酸乳不仅水分含量高,而且存在蛋白质、糖分和增稠剂等干扰物质,采用常规方法很难准确定量异黄酮。本研究以喷雾干燥的方法对大豆酸乳进行前处理,再以甲醇超声波提取乳粉中的异黄酮,然后采用高效液相色谱仪,以C18色谱柱为分离柱和甲醇／杉甲酸为流动相,在30min内,以0．8mL/min的流速梯度洗脱（从20／80／0．1到80／20／0．1）大豆酸乳粉的甲醇提取物,紫外检测器的波长设为254nm。结果表明：大豆酸乳粉中主要的异黄酮为染料木苷和大豆苷,总异黄酮含量为0．000544％～0．000937％。结论：利用这种方法可以准确的检测大豆酸乳中微量异黄酮含量．检出限大于百万分之一。     

均匀设计优化大豆异黄酮的超临界流体萃取

采用CO2超临界流体法提取大豆中异黄酮类成分.在单因素实验的基础上,利用均匀设计法考察萃取压力、萃取时间、萃取温度及药材粒度等4因素对大豆异黄酮提取率的影响,确定了CO2超临界流体法提取大豆异黄酮的最佳工艺为萃取压力45 MPa、萃取温度50 ℃、萃取时间4 h、药材粒度40目,在此工艺条件下进行实验,大豆异黄酮的提取率为(0.361±0.012)%.     

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。