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。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

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.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

A computer generator for randomly layered structures

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

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.