杧果黄色素的微波萃取及稳定性分析

微波萃取杧果黄色素,正交试验表明杧果色素提取效率的影响力大小:乙醇体积分数>料液比>微波功率>辐射时间.杧果色素最佳提取条件:体积分数为90%的乙醇为提取剂,料液比(原料质量(g)和提取液体积(mL)的比)为1∶30,微波辐射功率为280 W,辐射时间为50 s.该色素在80 ℃以下稳定性较好,对光的耐受性较差;色素在中性和碱性条件下稳定,耐还原性强,但耐氧化性较差.9 种金属离子中,Cu2 和K 对色素有明显的破坏作用,而Fe3 ,Fe2 ,Al3 ,Zn2 ,Na ,Ca2 和Mg2 对色素稳定性较好,并有不同程度的护色作用.葡萄糖和抗坏血酸对色素无不良影响;而蔗糖、苯甲酸钠和山梨酸钾对色素有破坏作用.     

苏木色素的微波提取及稳定性研究

对苏木色素的提取方法和色素的基本特性进行了研究。研究发现:苏木色素进行微波提取时,采用50%的乙醇水溶液(pH=6),料液比为1∶50,反应温度为50℃,提取时间为5 min,此时提取效果最佳;温度、金属离子(Na ,Ca2 ,Cu2 ,Al3*,Zn2 )和碳水化合物等对苏木色素的稳定性影响不大,但是金属离子Fe3 和氧化剂及还原剂对苏木色素有影响。     

微波辅助提取紫甘蓝色素

采用微波辅助提取法研究紫甘蓝色素提取的最佳工艺条件。以新鲜紫甘蓝为原料,采用单因素实验对紫甘蓝色素的微波提取方法进行了研究。在单因素实验基础上采用正交实验,确定紫甘蓝色素提取的最佳工艺条件为：固液比1：25（g／mL）、浸提剂酸性水pH为1、浸提时间2．5min、微波功率420W。     

甜菜叶红色素的提取优化及稳定性研究

以红甜菜叶为原料,通过单因素试验对甜菜叶红色素提取条件进行初步探究,并通过正交试验对色素提取工艺进行优化设计,初步探讨了红甜菜叶色素的稳定性。实验结果表明,影响提取最显著的因素是提取液的pH值,其次是乙醇浓度和提取时间,最后是提取温度。最佳提取条件为:提取液pH4.5,70%乙醇浓度,提取4.0h,提取温度20℃。对提取的甜菜叶红色素粗提液进行稳定性研究,结果表明,温度、pH对其稳定性影响显著,添加适量的维生素C和蔗糖有助于提高甜菜叶红色素的稳定性。     

微波法提取丁香色素

研究微波法提取丁香中食用色素的最佳工艺条件。方法：称取一定量的备用原料,选取微波功率、辐射时间、提取剂浓度、原料用量（g）与提取剂用量（mL）的配比（料液比）等进行单因素试验与正交试验。结果：微波功率是影响提取丁香色素的主要因素;影响丁香色素提取的顺序是微波功率〉料液比〉辐射时间〉提取剂浓度;最优工艺条件是微波辐射功率为500 W,辐射时间为120 s,提取剂为20%乙醇溶液,料液比为1 g：8 mL;提取液浓度与料液比之间存在交互作用。结论：正交试验是省时省力、结果易得的实用方法。     

微波法提取菊花色素的研究

目的:研究微波技术提取菊花色素的影响因素。方法:采用单因素试验和正交试验对比,确定微波条件下提取菊花色素的最佳条件。结果:微波辐射功率是影响菊花色素提取的主因素;各因子对提取效率的影响依次为:微波辐射功率>溶剂比例>提取时间>料液比;最佳提取条件为:微波辐射功率为300 w,辐射时间为150 s,提取液为60%的酸性乙醇,料液比为1∶30(g/ml)。结论:微波提取菊花色素具有缩短提取时间、降低环境污染、节能省耗等优点。正交试验是一种少、快、好、省的实验方法。     

金莲花黄色素的提取及其稳定性研究

研究了金莲花黄色素的提取性能及其稳定性，并对提取条件进行了优化实验。实验结果表明，金莲花色素易溶于丙酮，属于脂溶性色素；在pH=2～7时，金莲花色素的稳定性较好；氧化剂(H202)和还原剂(Na2S03)对其稳定性有影响，氯化钠、蔗糖介质对色素的稳定性影响不大，多种金属离子对其影响不显著；60℃以下色素的热稳定性较好，光对色素有降解作用。     

天女木兰色素提取工艺及稳定性

以采自吉林省通化石湖林场的天女木兰叶片为研究材料,对天女木兰色素提取工艺及色素稳定性进行了研究.结果显示:采用纯乙醇作为提取剂提取干叶中的色素效果最好;运用正交试验,确定了天女木兰色素提取的最佳工艺条件:温度40℃、时间4 h、m(固):V(液)为1:30(g/L);在色素稳定性试验中发现天女木兰色素受光、温度和pH的...     

草莓色素的提取及稳定性研究

本文以草莓为原料，用80%的酒精浸提制得草莓色素，，对其在不同pH介质、不同温度、不同光照条件下的稳定性及若干金属离子、山梨酸和葡萄糖对该色素的影响进行了研究，并分析对从大棚内与大田内种植的草莓中提取的色素的差异进行了比较研究。     

刺玫蔷薇果皮色素的提取及稳定性研究

文章根据色素的溶解特性，分别以几种不同的试剂提取野生植物刺玫蔷薇果皮的色素，从而找出最佳的提取溶剂及提取条件，同时对色素在不同条件下的稳定性进行了详细的研究，结果表明，该色素性能稳定，无毒副作用，具有进一步开发利用的价值．     

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。