超临界CO_2萃取条件对α-V_E和脂肪酸萃取效果的研究

以豆油脱臭馏出物为原料 ,利用超临界二氧化碳萃取技术浓缩α -VE,探讨萃取压力、萃取温度和二氧化碳流量对α -VE 和豆油脱臭馏出物中几种主要脂肪酸萃取效果的影响 ,结果表明 :萃取压力和萃取温度对α -VE 和几种主要脂肪酸在超临界二氧化碳中的溶解效果有非常显著的影响 ,萃取压力增加 ,萃取得率和α -VE 含量随着增加 ,萃取温度升高 ,萃取得率下降 ,而二氧化碳流量对萃取效果影响较小 在萃取温度 30 8K、萃取压力 1 8MPa、二氧化碳流量 6～ 1 0L/min的萃取条件下 ,可以获得较高的萃取得率和α -VE 浓度     

超临界CO2萃取条件对α-VE和脂肪酸萃取效果的研究

以豆油脱臭馏出物为原料,利用超临界二氧化碳萃取技术浓缩α-VE,探讨萃取压力、萃取温度和二氧化碳流量对α-VE和豆油脱臭馏出物中几种主要脂肪酸萃取效果的影响,结果表明萃取压力和萃取温度对α-VE和几种主要脂肪酸在超临界二氧化碳中的溶解效果有非常显著的影响,萃取压力增加,萃取得率和α-VE含量随着增加,萃取温度升高,萃取得率下降,而二氧化碳流量对萃取效果影响较小.在萃取温度308K、萃取压力18MPa、二氧化碳流量6～10L/min的萃取条件下,可以获得较高的萃取得率和α-VE浓度.     

超临界CO2萃取条件对a—VE用脂肪酸萃取效果的研究

以豆油脱臭馏出物为原料,利用超临界二氧化碳萃取技术浓缩a－VE,探讨萃取压力、萃取温度和二氧化碳流量对a－VE和豆油脱臭馏出物中几种主要脂肪酸萃取效果的影响,结果表明：萃取压力和萃取温度时a－VE和几种主要脂肪酸在超临界二氧化碳中的溶解效果有非常显著的影响,萃取压力增加,萃取得率和a－VE含量随着增加,萃取温度升高,萃取得率下降,而二氧化碳流量对萃取效果影响较小。在萃取温度308K、萃取压力18MPa、二氧化碳流量6－10L/min的萃取条件下,可以获得较高的萃取得率和a－VE浓度。     

牛蒡籽油的超临界CO2流体萃取研究

应用超临界二氧化碳萃取技术,研究了牛蒡籽油的提取工艺,着重探讨了萃取压力、温度、萃取时间、CO_2流量对油脂萃取率的影响,优化了工艺条件:压力30Mpa,温度50℃,时间3h,CO_2流量30kg/h.利用GC/MS分析了牛蒡籽油的成分组成,比较了超临界CO_2萃取的油样和乙醚萃取油样的理化性质。     

响应面法优化超临界CO_2流体萃取红橘种子油

以红橘种子为原料,研究了萃取时间,萃取压力,萃取温度,CO_2流量4因素对萃取红橘籽油得率的影响,以期获得超临界CO_2流体萃取红橘种子油的最佳工艺.经响应面分析方法,确定了超临界CO_2流体萃取柑橘种子油的最佳工艺实际操作条件:萃取压力27MPa,萃取温度46℃,CO_2流量33L/h,萃取时间2.3h,在此条件下红橘种子油得率为31.90%.所得油脂色泽金黄,透明澄清,且符合食用植物油的常规理化标准.     

超临界CO2提取青蒿素的工艺

研究了超临界CO2提取青蒿素的工艺,考察了粒度、压力、温度、时间、CO2流量等影响因素.以萃取率为目标,综合考虑产品收率,优化了超临界萃取工艺条件,得到较佳的操作条件:萃取压力20 MPa,萃取温度50℃,每千克原料CO2质量流量1 kg/h,分离器Ⅰ的温度为60℃,压力为14 MPa.在优化条件下萃取4 h,萃取率达到95%以上,萃取物纯度在15%以上.     

银杏叶黄酮超临界二氧化碳萃取条件研究

通过正交实验研究，对超临界流体萃取银杏叶黄酮类化合物的工艺进行了优化设计．实验结果表明影响萃取得率的各因素强烈程度的顺序由大到小为：夹带剂浓度、萃取压力、萃取温度；在流量为35kg／h，萃取时间为2h的条件下，最佳萃取实验工艺条件为：萃取压力15MPa，乙醇浓度为90％，萃取温度为55℃，此时，黄酮类化合物萃取得率较理想。     

超临界二氧化碳萃取鄂西烤烟挥发油的研究

采用正交实验法对超临界CO2萃取鄂西烤烟挥发油的条件进行了研究.考察了萃取温度、压力、CO2流量等因素对鄂西烤烟挥发油提取率的影响.得到了超临界CO2萃取鄂西烤烟挥发油的最佳实验条件:萃取压力15MPa、温度40℃、CO2流量45kg·h-1和时间80min,得率为2 86%.水蒸汽蒸馏提取率为0 96%.超临界CO2萃取的收率高,萃取时间短.     

超临界CO2萃取栝楼籽油工艺条件优化

利用超临界CO₂萃取技术对栝楼籽油的萃取条件进行了研究.采用单因素试验和正交试验分析了栝楼籽粉碎细度、萃取温度、萃取压力和萃取时间对萃取得率的影响,确定了萃取栝楼籽油的最佳工艺条件.结果表明,利用超临界CO2萃取栝楼籽油的最佳工艺条件为栝楼籽粉碎细度90目、萃取温度50 ℃、萃取压力30 MPa、萃取时间3 h,萃取得率可达39.6%.     

影响USFE萃取海藻EPA和DHA的因素分析

研究了萃取温度、压力、时间、CO2流量和超声参数对超声强化超临界流体萃取海藻EPA和DHA的影响,发现与超临界流体萃取相比,超声强化超临界流体萃取过程使CO2流量减小,萃取温度及压力降低,萃取时间缩短,而EPA和DHA的萃取率提高,在单因素实验的基础上进行了正交实验,结果表明,超声强化超临界流体萃取EPA和DHA的最佳工艺条件为：萃取温度35℃,压力25MPa,时间3．0h,CO2流量3L／h。     

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.     

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.     

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     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has