乳化剂芥酸蔗糖酯的合成

以蔗糖、芥酸为原料,首先芥酸甲酯化合成芥酸甲酯;然后以硬脂酸钾为乳化剂,使芥酸甲酯与蔗糖在较低温度下达到相溶状态,在均相条件下进行酯交换反应合成芥酸蔗糖酯.考察了不同的糖酯比、反应温度、反应时间等对芥酸蔗糖酯产率的影响,得到了较佳的反应条件:n(蔗糖)∶n(芥酸甲酯)=1.5∶1;乳化剂(硬脂酸钾)用量为6%;催化剂(碳酸钾)用量为7%;反应时间为4 h;反应温度为135℃.芥酸蔗糖酯的产率(以单酯含量计)为46.57%.     

水-醇为溶剂合成蔗糖月桂酸单酯的工艺研究

以水-醇作为溶剂,在乳化条件下合成蔗糖月桂酸单酯.研究反应温度、时间、投料比的影响.在一定条件下,收率达到近80%.对反应中提高蔗糖月桂酸单酯的量及对薄层色谱分析用显色剂的条件进行了研究.     

氮杂环卡宾催化酯交换合成蔗糖酯

氮杂环卡宾由于其强的亲核性可以催化酯交换反应,但其用于蔗糖的酯交换反应尚未见报道。本文探索氮杂环卡宾催化的醋酸乙烯酯对蔗糖的酯交换反应,得到一系列的蔗糖酯(单酯、双酯和多酯),通过HPLC-MS-MS对其进行定性定量分析,以总酯化率为指标,得到其最佳反应条件为:DMF为溶剂,糖酯比1∶10,反应温度100℃,时间8 h,催化剂用量为10%,总酯化率达到88%,最后通过红外光谱确定得到蔗糖酯。本文研究可为氮杂环卡宾催化蔗糖的酯交换反应提供依据。     

离子液体中酶法合成蔗糖-6-月桂酸单酯的研究

以脂肪酶Lipozyme TLIM为催化剂在离子液体中选择性催化蔗糖和月桂酸乙烯酯合成了蔗糖月桂酸酯。利用单因素试验考察了酶制剂、离子液体种类、温度、原料的摩尔比、酶浓度对产率的影响,得到在离子液体[Bmim]BF4,反应最佳温度为45℃、糖酯最佳摩尔比为1∶4,最佳酶浓度为60 mg/mL。用TLC、HPLC、MS和NMR等手段对蔗糖-6-月桂酸单酯进行了表征。     

反应性乳化剂十二醇马来酸钠的合成及其性能研究

首先利用十二醇（DA）和马来酸酐（MLAD）通过酯化反应合成单酯,然后加碱中和制得反应性乳化剂十二醇马来酸钠,得到了本反应最佳工艺条件．试验结果表明,当催化剂含量为醇酸总质量的1％,醇酸摩尔比为1：1,反应温度为80℃,反应时间为3h时,所得粗产物中十二醇马来酸单酯的含量最高．对自制的反应性乳化剂进行了乳化力测试,试验结果表明,自制反应性乳化剂乳化力优于常用的阴离子乳化剂十二烷基硫酸钠（SDS）．用最大气泡法测溶液表面张力,得其临界胶束浓度为8mmol／L．用半连续种子乳液聚合法制得乳液,试验结果表明,与传统乳液聚合相比,由反应性乳化剂制得乳液聚合物的剪切强度、抗水性能、抗污性能、透明性都有明显改善．     

甜高粱秸秆中可溶性糖提取及组成分析

建立高效、低耗的甜高粱可溶性糖提取方式条件,并分析糖的种类及比例.通过单因素试验,分别考察料液比、浸提温度、浸提时间对浸提率的影响.蒽酮法测定可溶性总糖含量,3,5-二硝基水杨酸法测定还原性糖含量,离子色谱法测得甜高粱秸秆中可溶性糖的种类.当料液比1∶4,温度60℃,浸提时间2 h条件下浸提得到的糖最多,水浸提法甜秸秆可提取出19.01%的(以葡萄糖计)总糖.甜秸秆中含有43.35%的蔗糖、14.2%的葡萄糖、11.36%的果糖.     

固定化蛋白酶区域选择性催化合成蔗糖己二酸单乙烯酯

用固定化蛋白酶FG-F在有机溶剂中催化蔗糖和己二酸二乙烯酯(DVA)合成了蔗糖己二酸单乙烯酯.用吸附法以硅藻土为载体研究了蛋白酶FG-F的固定化.固定化条件优化为:pH值8～10,温度为20～40℃,磷酸盐缓冲溶液的浓度范围为0.02～0.06 mol/L,酶与硅藻土的质量比为1:6.固定化酶在含水量为0.25%的DMF中,于45℃,220 r/min,pH值为8时,转酯化催化活力最高.转酯化反应3 d,DVA生成2-0-己二酸单乙烯基蔗糖酯的转化为52%.     

蔗糖乙酯的合成工艺研究及分离分析

本文采用膦腈碱P2为催化剂对乙酸乙烯酯和蔗糖的酯交换反应进行研究。通过正交试验的方法,以多酯酯化率为优化目标,得到最佳反应条件:反应温度353 K(80℃),n(蔗糖):n(醋酸乙烯酯)=1∶10,n(催化剂)∶n(蔗糖)=0.15∶1反应时间为10 h。其多酯酯化率可达77.09%,八酯酯化率达40%。通过TLC、HPLC-MS-MS对其进行定性定量分析,柱色谱分离得到蔗糖八乙酯,并通过红外光谱和NMR确定蔗糖八乙酯结构,经柱色谱分离得到蔗糖八乙酯的含量与HPLC-MS-MS分析结果基本一致。因此,用HPLC-MS-MS检测方法可简单、快速测定蔗糖酯。     

衣康酸聚氧乙烯醚的合成及其在制备纳米胶囊中的应用

采用两步法合成了一种非离子型的可聚合乳化剂衣康酸十二醇聚氧乙烯醚-3,并将其与阴离子型衣康酸单十二酯丙基磺酸钠复配应用于细乳液聚合法制备氯菊酯纳米胶囊.采用1H-NMR、FT-IR、TEM等手段对可聚合乳化剂、氯菊酯纳米胶囊结构与形貌进行表征.结果表明:衣康酸聚氧乙烯醚含量占油相的质量百分数为1%;农药和单体比例为1∶1时所得到的纳米胶囊包覆效果最佳.     

马蹄奶饮料加工技术研究

研究了马蹄奶饮料加工技术,通过添加乳化剂.柠檬酸解决了乳蛋白质絮凝问题.实验结果表明,最佳配比为:马蹄汁50%、糖6%、奶粉4%、蔗糖酯0.25%,羧甲基纤维素钠0.15%,柠檬酸0.1%.     

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