超声辐照对有机相脂肪酶催化酯化反应的促进

探讨了超声辐照对有机相中脂肪酶催化有机硅醇与脂肪酸酯化反应的促进作用, 系统地研究了超声功率、 超声作用方式、 底物脂肪酸的碳链长、 反应体系的水活度等对超声辐照促进有机相脂肪酶催化酯化反应的影响. 研究表明, 适宜的超声辐照可显著提高有机相脂肪酶催化酯化反应的速度; 底物的碳链越长、 反应体系的水活度越大, 超声对酶催化酯化反应的促进作用就越明显.     

水活度对有机相中脂肪酶催化酯化的影响

在有机相中以Candida rugosa脂肪酶催化正丁酸和醇之间的酯化反应,用已知水活度的盐/盐水合物对控制反应体系的水活度.在其他条件恒定时,筛选出最适底物醇为正丁醇,最适反应溶剂为正庚烷;考察了盐对的加入量以及盐对的比例对反应过程的影响,并进一步研究了水活度对酯化反应的影响.结果表明,用盐/盐水合物对控制反应体系水活度是可行的,反应的初速度和转化率随水活度的增加而增加,在水活度为0.76时,转化率达到72.43%.     

有机介质中固定化酶催化萘普森与硅醇的酯化反应

柱状假丝酵母脂肪酶,在异辛烷体系中可选择性地催化Ｓ－２－（６－甲氧基－２萘基）丙酸（萘普森）与三甲基硅甲醇发生酯化反应。利用硅藻土吸附固定化酶有效地改善了酶在有机介质中的分散状态,提高了催化效率。选择和确定了四氯化碳作为辅溶剂——底物酸的增溶剂,并对辅溶剂与异辛烷的比例、醇浓度及温度对酯化反应过程的影响进行了研究。结果表明：在酯化反应中,高浓度的醇具有抑制作用;较高反应温度也导致酶的失活;去除水有利于酯化反应的进行。     

水含量对脂肪酶促有机硅烷醇酯化反应的影响

水含量对有机相中脂肪酶催化有机硅烷醇与戊酸的酯化反应有显著的影响。脂肪酶Ｌ＿１７５４的最适温度随有机溶剂中水含量的降低而提高，溶剂中的水含量不影响固定化脂肪酶Ｌｉｐｏｚｙｍｅ的最适温度。对所研究的反应体系，水含量为４．１７ｍｍｏｌ／Ｌ时，Ｌｉｐｏｚｙｍｅ的活力最高，而脂肪酶Ｌ＿１７５４的最适水含量为３．０ｍｍｏｌ／Ｌ。     

脂肪酸高级烷醇酰胺的研制

以脂肪酸为原料经酯化、缩合制取高级烷醇酰胺。用正交实验设计考察了反应温度、反应时问、催化剂种类及其用量、原料配比等对酯化、缩合反应的影响,得出了优化反应条件。     

PCl_3促进下“一锅法”合成有机羧酸酯的反应研究

探索了PCl3促进下有机羧酸与醇或酚类化合物"一锅法"合成有机羧酸酯的反应,制备了17种有机羧酸酯类化合物.高级饱和脂肪酸,饱和和不饱和低级脂肪酸、取代芳香族羧酸均可以与伯醇、仲醇或酚类化合物发生酯化反应,得到较高产率的产物.该方法条件温和,步骤简单,操作简便,产率高,为有机羧酸酯类化合物的合成提供了一条简便方法.     

超声对固定化脂肪酶生物转化有机硅化合物的促进作用

超声作用可以促进固定化脂肪酶Ｌｉｐｏｚｙｍｅ催化有机介质中有机硅椁与脂肪酸的酯化反应。在超声频率２０ＫＨｚ时,以功率６０Ｗ作用３０秒、间歇３０秒的超声作用较为适宜。经过超声预处理后酶催化有机硅醇与脂肪酸脂化反应速率和转化率提高。对超声作用机理进行了探讨,超声作用对酶催化反应的促进是十分明显的．     

酶促棕榈酸鲸蜡酯合成的底物抑制作用

对实验室自制的固定化Candida sp. 99-125脂肪酶在正己烷中催化棕榈酸和鲸蜡醇的酯化反应的动力学机制进行了初步研究,结果表明：反应为动力学控制,不存在扩散限制,底物浓度对反应速率的影响符合Ping-Pong Bi-Bi反应机制。但在不同的底物浓度范围内存在不同程度的底物抑制作用,其中以长链醇的抑制为主。本文根据底物浓度由低到高,划分了三个底物浓度范围,在不同的范围内分别研究了两个底物的抑制作用,并选择不同的动力学模型,求得了动力学常数。     

芳香醛直接合成芳香羧酸酯的新反应研究

针对传统酯化反应中固有的转化率不高、反应条件苛刻等科学问题,作者发展了一条新的合成芳香甲酸酯的合成方法。该方法以芳香醛和醇为底物,在过硫酸氢钾复盐存在下即可高产率的转化为芳香甲酸酯。研究结果表明该反应可以适用于含有吸电子、供电子等不同的芳香醛,也适用于甲醇、乙醇、异丙醇等不同的醇,底物适用范围较宽,反应条件温和,反应收率较好。     

棕榈油乙酯化合成脂肪酸乙酯及其动力学

为了研究反应条件对乙酯化反应的影响，提高脂肪酸乙酯的转化率，本文以氢氧化钠催化棕榈油与无水乙醇发生酯化反应合成棕榈油脂肪酸乙酯。首先考察棕榈油的理化性质，然后通过单因素实验和正交实验考察反应过程中醇油物质的量比、催化剂用量、反应温度、反应时间对乙酯化反应合成棕榈油脂肪酸乙酯转化率的影响，并用FT-IR和TLC对棕榈油脂肪酸乙酯进行表征和分析。结果表明：优化的工艺条件为醇油物质的量比为7∶1,催化剂质量分数为0.8%(占棕榈油质量),反应温度为75℃,反应时间为2.0 h时，棕榈油脂肪酸乙酯的转化率为95.6%,且高于同类产品。动力学研究表明：酯化过程为二级反应，在反应温度为60、70、80℃的反应速率常数分别为0.059 8、0.102 1、0.166 3 L/(mol·min),活化能为2.033 0 kJ/mol。     

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.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

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。     

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     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.