硫酸氢钠催化合成没食子酸正丁酯

以没食子酸和正丁醇为原料，采用一水合硫酸氢钠作催化剂合成没食子酸正丁酯．研究了一水合硫酸氢钠用量、正丁醇用量和反应时间对没食子酸正丁酯收率的影响．当没食子酸，正丁醇和硫酸氢钠的物质的量比为1：15：0.034。回流分水5h，酯收率达92．3％．     

硅胶载体酸催化合成没食子酸正丙酯

采用硅胶载体酸为催化剂，合成了没食子酸正丙酯，给出了最佳的酯化条件：催化剂用量12％（与没食子酸质量比），酸醇摩尔比1：6，反应时间4.5h，反应温度105－110℃，醇产率可达87％。     

没食子酸丙酯合成工艺研究

报道没食子酸和正丙醇在硫酸等酸性催化剂存在下，采用外脱水和水溶剂重结晶法制造食品级没食子酸丙酯。该方法与传统硫酸法相比，具有简便、安全、收率高和产品质量稳定等优点，适于工业生产采用。     

碱式没食子酸锑对涤纶的阻燃试验

介绍了用自制的碱式没食子酸锑和四溴双酚Ａ（ＴＢＡ）组合成新型阻燃剂，对涤纶阻燃性能进行了试验研究。     

食品抗氧化剂没食子酸丙酯的合成

本文报导了以没食子酸和丙醇为原料合成没食子酸丙酯的多种合成方法,其中最有价值的是以对甲苯磺酸为催化剂和烃类带水的酯化法。该法有操作简单、安全、易纯化等优点,收率高于87%。没食子酸丙酯是通用的食品抗氧化剂,应用试验表明,它能阻延油脂和油基食品的氧化变质。     

聚酯催化剂乙二醇锑的合成

过量的乙二醇与三氧化二锑在一定条件下直接酯化脱水,一步法合成了聚酯催化剂乙二醇锑.运用正交设计原理,探讨了反应物配比、反应温度、反应时间等工艺条件对产品收率的影响.结果表明,合成乙二醇锑的最佳工艺条件为:三氧化二锑与乙二醇的摩尔配比为1:45,反应温度为190℃,反应时间为150 min,产品收率达81.12%,所得乙二醇锑中锑含量优于现行企业标准.     

壳聚糖硫酸盐催化合成没食子酸丙酯

以壳聚糖硫酸盐为催化剂,用没食子酸与正丙醇直接酯化合成了没食子酸丙酯(PG),用正交试验确定了醇酸摩尔比、催化剂用量、反应时间对PG收率的影响.得到了最佳工艺条件为:醇酸摩尔比为10∶1,催化剂用量为1.0g,反应时间为4h,PG的收率可达91.3%.实验表明,该催化剂用于合成PG具有良好的催化活性和重复使用性.     

新型汽油辛烷值改进剂

目的 合成一种新型汽油辛烷值改进剂——甲氧基异丁酸烷基酯。方法采用烃化反应合成甲氧基异丁酸烷基酯，研究法测定汽油辛烷值。结果甲醇与甲基丙烯酸甲酯的配料比（物质的量比）为1．8：1，反应时间为4h，催化剂用量为15％（质量分数），阻聚剂的量为0．2％（质量分数），此条件下产品收率为87．3％。结论改进剂添加量为3％～7％（体积分数）时，汽油辛烷值可提高1．5～10个单位。     

选择性甲基化反应研究——嗪草酮的合成新方法

研究了４－氨基－６－特丁基－３－甲硫基－１,２,４－三嗪－５（４Ｈ）－酮（通用名嗪草酮,Ｍｅｔｒｉｂｕｚｉｎ）的合成新方法,通过对反应介质,甲基化试剂的选择及反应条件的优化研究,使产品收率高（一般＞９５％）,纯度高（＞９３％）,同时用核磁共振谱、红外光谱、元素分析等证实了产品的结构     

TiSiW_(12)O_(40)/TiO_2催化合成抗氧化剂没食子酸丙酯的研究

以TiSiW12O40/TiO2为催化剂,用没食子酸与正丙醇直接酯化合成了抗氧化剂没食子酸丙酯(PG),通过正交试验确定了醇酸物质的量比、催化剂用量、反应时间对PG收率的影响.得到的最佳工艺条件为:醇酸物质的量比为8∶1,催化剂用量为没食子酸质量的2%,反应时间为3 h,PG的收率可达95.1%.实验表明,该催化剂用于合成PG具有极好的催化活性和重复使用性.     

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.     

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.     

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.     

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.     

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.     

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that