相转移催化剂催化合成DL-扁桃酸

分子结构为C8H20BrN的季铵盐四乙基溴化铵经实验证明是合成DL-扁桃酸的一种优良的相转移催化剂。研究以苯甲醛和三氯甲烷为原料,在氢氧化钠存在下,应用相转移催化法合成扁桃酸,并探讨反应条件如反应摩尔比、反应时间、催化剂用量对产率的影响。结果表明合成DL-扁桃酸的最佳反应条件为:反应温度65℃,反应时间60min,n(苯甲醛)∶n(三氯甲烷)∶n(四乙基溴化铵)=1∶2∶0.002,产品收率可达到72.41%。     

甘氨酸锰络合物的制备与结构表征

以甘氨酸和金属锰盐为主要原料,制备甘氨酸锰络合物,探讨反应温度、反应时间、反应体系p H值等因素对甘氨酸锰产率的影响,确定最佳合成工艺,并通过红外光谱表征产物结构.实验结果显示,制备甘氨酸锰的最佳反应条件为反应温度70℃,反应时间2.5 h,反应体系p H5~6,在最佳条件下制备的甘氨酸锰络合物的产率为47.86%;红外光谱证明产物为甘氨酸锰络合物.     

2-辛基十二烷基缩水甘油醚的合成

以固体氢氧化钠、格尔伯特二十醇和环氧氯丙烷为原料,采用四丁基溴化铵为相转移催化剂,合成了2-辛基十二烷基缩水甘油醚。讨论了原料摩尔比、四丁基溴化铵的用量、反应温度、反应时间对反应产率的影响。最终确定最佳反应条件是:n(格尔伯特二十醇)∶n(环氧氯丙烷)∶n(固体氢氧化钠)=1.00∶1.15∶1.20;四丁基溴化铵用量为0.05(相对醇的摩尔比);反应温度为50℃;反应时间为4 h。在此条件下可得产率为79.8%的2-辛基十二烷基缩水甘油醚,用盐酸-丙酮法测得其环氧值为0.232。最终产物结构通过红外光谱分析得到证实。     

DMAP催化“一锅法”合成4,6-二苯基-2-氨基-3,5-二氰基-4H-吡喃衍生物

使用DMAP为催化剂,芳香醛、苯甲酰乙腈、丙二腈为原料,乙醇作溶剂,一锅法合成2-氨基-3,5-二氰基-4H-吡喃衍生物.通过单因素试验考察了催化剂用量、反应时间、温度及原料摩尔比对目标产物产率的影响.结果表明:合成该化合物的优化工艺条件为:催化剂的最佳用量为苯甲酰乙腈物质的量的10%,反应时间20 min,反应温度为70℃,原料摩尔比n(不同取代的苯甲醛)∶n(苯甲酰乙腈)∶n(丙二腈)=1.1∶1.0∶1.1.产率在89.9%～98.5%之间.此方法为2-氨基-3-氰基-4H-吡喃衍生物的合成提供了一种高效、快速的合成路线.     

氯化锡催化合成苯甲酸乙酯的研究

以苯甲酸和无水乙醇为原料,采用氯化锡(SnCl4·5H2O)作催化剂合成苯甲酸乙酯,考察了催化剂用量、原料配比和反应时间等因素对反应产率的影响.确定了氯化锡作为催化剂的最佳反应条件:n苯甲酸∶n无水乙醇∶n氯化锡=1∶4∶0.01;反应温度为88℃;反应时间为60min;转化率(以苯甲酸计)可达93.5%.     

超声辐射下水介质中KF-Al_2O_3催化合成2-呋喃亚甲基氰乙酸乙酯

超声波辐射下以水为溶剂,氧化铝固载氟化钾催化合成了2-呋喃亚甲基氰乙酸乙酯.最佳反应条件:n(呋喃甲醛)∶n(氰乙酸乙酯)= 1∶1,催化剂用量为1.0 g,反应温度35 ℃时反应5 min,产率可达97.8%.     

丙酮保护法合成单硬脂酸甘油酯研究

以甘油、硬脂酸为原料,对甲苯磺酸为催化剂,丙酮为基团保护剂,氯仿为带水剂,采用基团保护法合成单硬脂酸甘油酯。进而考察了反应物摩尔比、反应温度、反应时间、催化剂用量等对产物产率的影响,确定了最佳反应条件。研究发现,最佳合成条件为:n(甘油)∶n(丙酮)∶n(硬脂酸)=1.25∶2.5∶1(摩尔比),缩合反应温度为80℃、时间为3h、催化剂用量为硬脂酸摩尔数的2.5%,酯化反应温度为140℃、时间为4h、催化剂的用量为硬脂酸摩尔数的2.5%;在此条件下,单硬脂酸甘油酯的产率最高可达96.42%。     

对羟基苯甲酸苄酯合成方法的改进

采用改进工艺,以正十六烷基三甲基溴化铵为相转移催化剂,水为溶剂,对羟基苯甲酸和氯化苄为主要原料,合成对羟基苯甲酸苄酯.结果表明,n(酸)∶n(氯化苄)=1 00∶1 40,催化剂用量2 3%(与酸的摩尔比),反应温度100℃,反应时间5h,产率86 48%.     

N-月桂酰基乙二胺三乙酸的合成

采用乙二胺和月桂酸为原料,合成N-月桂酰基乙二胺(中间体A),A与一氯乙酸反应得产物N-月桂酰基乙二胺三乙酸(终产物B),通过红外光谱(IR)对合成的中间体N-月桂酰基乙二胺(A)及产物N-月桂酰基乙二胺三乙酸(B)进行结构表征.讨论了反应条件对产率的影响,合成中间体最佳条件为温度110 ℃左右,反应时间约3 h,n乙二胺∶n月桂酸=4∶1.终产物的合成条件为温度80 ℃,反应时间约0.5 h,n氯乙酸∶n中间体=6∶1.     

微波辐射明矾催化合成阿司匹林的研究

文中以水杨酸、乙酸酐为主要原料,以明矾作为催化剂,用微波法快速合成阿司匹林。系统讨论了反应物料比、催化剂用量、微波反应温度、微波反应时间及微波辐射功率等因素对产率的影响,确定了阿司匹林的最佳合成工艺条件。通过试验研究,优化出最佳合成工艺条件为:n(水杨酸)∶n(乙酸酐)=1∶2,催化剂用量为水杨酸质量的7.2,微波反应温度70℃,微波反应时间20 min,微波辐射功率400 W时,纯化后阿司匹林产率达到83.01。既可强化学生的环保意识,又可使学生掌握绿色化学的实用技术。     

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.     

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.     

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.     

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

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

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.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-