溶剂萃取-重结晶法提纯氨基甲酸甲酯

用氯仿作为萃取剂,研究了用尿素醇解法合成氨基甲酸甲酯(简称MC)粗产品的提纯方法.粗产品与氯仿在50℃恒温条件下萃取1 h,恒温过滤,滤液自然降温至室温,在室温下重结晶20 min,所得结晶在45℃烘箱中干燥30 min,可获得质量分数达99.9%的MC产品.由粗品一次萃取-结晶的MC回收率超过92%.     

高效有机吸附质在饮用水深度处理中的应用研究

本文将自行合成的室温固化的聚丙烯酸酯(polyacrylate(s)，简写为PA)涂膜后用于饮用水深度处理，并利用固相微萃取与气相色谱联用技术（SPME-GC）评价其涂层对饮用水中的氯仿的萃取效率，发现萃取50min，萃取效率就可达到50％。说明室温条件下固化的聚丙烯酸酯对水中的有机物氯仿有较佳的萃取效果。     

盐酸林可霉素的萃取与结晶提纯

为了降低盐酸林可霉素粗品中的B组分含量,采用萃取与结晶相结合的方法,分别研究了萃取结晶过程中萃取荆种类、用量、原料浓度、溶液pH等条件以及溶析结晶过程中的混合速率对产品纯度的影响.结果表明:丁醇或氯仿有较高的萃取效率;降低原料浓度或在萃取、反萃时分别保持溶液pH为11和5均有利于提高产品中的A组分含量;结晶过程中提高搅拌速率有利于提高产品纯度.以氯仿为萃取荆,经过单级萃取,结晶后产品中A组分纯度最高可达97.86%.     

灵芝三萜类化合物的提取

用氯仿回流提取木屑栽培灵芝子实体，氯份提取浓缩液经碳酸氢钠溶液萃取，盐酸酸化后，析出絮状沉淀．沉淀再用氯仿提取，经减压干燥得提取物粗品，三次提取实验得率为0.41％～0．93％．粗品对Salkowski，Lieberman，磷钨酸和香草醛等试剂呈三萜类特有的阳性反应，初步可以肯定此提取粗品为三萜类化合物．     

从菜子油中提取磷脂的研究

进行了从菜子油中提取磷脂方法的研究。试验证明,菜子油水化脱磷的加水量为0.85％～1％,水化温度为70℃～80℃,水化时间60min,搅拌速度80r/min,第一次萃取加丙酮为10∶1,萃取时间为30min,制取磷脂得率较高。试验还证明,以直接用含50％水分的粗磷脂加丙酮萃取效果较好,去油磷脂得率较高。     

白阿魏菇菌丝体多糖分离纯化工艺的优化和结构分析

对白阿魏菇菌丝体多糖的提取和纯化进行了优化设计，粗多糖经DEAE—cellulose及SephadexG-100柱层析，纯化得纯多糖(PNMP)，该多糖经聚丙烯酰胺凝胶电泳，SephadexG-100柱层析和紫外光谱分析鉴定纯度；通过红外光谱，气相色谱对PNMP进行组分分析；再用高碘酸氧化，Smith降解和测硫酸基法来鉴定其化学结构．结果表明，白阿魏菇菌丝体多糖提取最佳工艺为，用水浸提3h，pH7．O，温度90℃，搅拌，料水比为1／15，浸提2次，醇析浓度70％；蛋白质去除中，V氯仿：V正丁醇=2：V样品：V氯仿-正丁醇=2：1，萃取时间为40min，得粗多糖CPNMP，纯度为59．2％；在结构分析中，纯多糖(PNMP)纯度为83．22％，硫酸基含量为7．5％；该多糖至少由半乳糖、甘露糖、葡萄糖、阿拉伯糖等组成，糖苷键连接方式为1→3，1→6。     

结晶法精制玉米须中植物甾醇

植物甾醇具有重要的食用和药用价值,研究了农业废弃物玉米须中植物甾醇的提取结晶工艺.玉米须经过皂化处理后,通过超声波辅助提取,得到的粗品经氯仿萃取后,通过正交试验确定最佳结晶工艺条件:粗品和乙酸乙酯以1mL∶1g的料液比在0℃处理12h,可得到植物甾醇的结晶,再滴加甲醇抽滤后得到植物甾醇重结晶,纯度为92.36%±0.33%(w/w).     

甘薯渣酶解制备高纯度结晶葡萄糖和可溶性膳食纤维的研究

研究了甘薯渣酶解法制备葡萄糖及结晶生产高纯度结晶葡萄糖的工艺.新鲜甘薯渣加入1倍体积的水混匀,加入20 U/g的耐高温α-淀粉酶,90℃下液化60 min,冷却至室温后按300 U/g加入糖化酶,60℃下酶解6 h;酶解液加入1％的大孔树脂吸附除去杂质;糖溶液减压浓缩至葡萄糖质量分数为70％,65℃下加热30 min,...     

从黑稻秆中提取黑米色素

在pH=2的条件下，用乙醇-水作溶剂从黑稻秆中萃取黑米色素．研究了萃取溶剂、温度、萃取时间对黑米色素的萃取效率的影响，并对萃取产物进行了表征．实验结果表明，在温度为70℃，用60％的乙醇水溶液萃取60min的萃取效果最好，萃取率为3．59％．这种萃取黑米色素的工艺简单，无毒害，无污染．     

N,N二烷基取代酰胺萃取食用柠檬酸及其机理

本文以N,N二烷基取代酰胺为萃取剂,食品香料丁酸丁酯为稀释剂,直接从某柠檬酸厂发酵料液,以粉状活性炭并添加适量食盐,利用发酵温度适当加热预处理破乳后,在室温下五级逆流萃取,萃取率达96.6％,以60℃左右水七级错流反萃率达99％,所得产品的紫外,红外谱图与厂方用钙盐法生产之产品谱图基本一致。     

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