苦丁茶中熊果酸的提取工艺

在苦丁茶中提取熊果酸的过程中,采用正交实验研究了乙醇体积分数、液固比、提取时间、提取温度、提取次数等对熊果酸浸出率的影响.正交实验的方差分析结果表明:对于熊果酸的浸出率,提取时间的影响最大,乙醇浓度和固液比的影响次之;最佳回流提取工艺条件为:在85℃水浴中,以90%(体积分数)乙醇水溶液为提取液,液固比为14 : 1,提取2次,每次提取2.5 h时,熊果酸的浸出率可达到1.44%.     

菟丝子总黄酮提取工艺的研究

优选水浴振荡提取方法,以菟丝子总黄酮质量分数为考察指标,研究提取溶剂浓度、提取温度、固液比、提取时间、提取次数等因素对总黄酮质量分数的影响.通过正交试验,确定菟丝子总黄酮提取的最佳工艺条件为:提取温度60℃,固液比1∶14,乙醇体积分数55%,提取时间2h,提取次数2次.     

优化红花桑寄生多糖提取工艺的研究

采用水提醇沉法从红花桑寄生叶中提取多糖.在单因素实验的基础上,分别对影响红花桑寄生多糖水提的4个主要因素——料液比、提取时间、提取温度、提取次数和影响乙醇沉淀多糖的3个主要因素——乙醇体积分数、静置时间、浓缩倍数,设计了L9(34)4因素3水平正交实验,以多糖得率为指标,采用方差分析对结果进行统计分析,结果表明提取次数和乙醇体积分数对得率影响最大.确立了水提红花桑寄生多糖的最佳工艺条件为:提取次数3次,提取温度95℃,料液比为1∶25,提取时间2h;最佳醇沉条件为:浓缩倍数1倍,乙醇体积分数80%,静置时间24h.     

光叶山楂熊果酸提取工艺研究

采用溶剂提取技术,以熊果酸提取率为指标,对提取工艺进行了研究.结果证明:乙醇体积分数85%、提取温度88℃、提取时间120 min、液固比8∶1、提取次数为2次时,熊果酸提取率最高,为92.5%.     

乌蔹莓多酚提取工艺研究

试验以乌蔹莓全草为材料,采用Folin-Ciocalteu法测定多酚的含量,通过单因素和正交试验对乌蔹莓多酚提取工艺的乙醇体积分数、提取时间、提取温度、料液比4个因素进行研究,结果表明:各因素对多酚得率的影响大小为:D(提取温度)A(乙醇体积分数)C(提取时间)B(料液比).最佳工艺组合为A2B3C2D2,即最优提取工艺条件为:乙醇体积分数60%,料液比1∶70,提取时间1 h,温度60℃,乌蔹莓多酚得率为0.89%.     

昙花总黄酮提取工艺研究

研究昙花总黄酮的提取工艺条件.采用传统热回流浸提法,以乙醇为提取溶剂,考察溶剂体积分数、提取温度、提取时间以及料液比对昙花总黄酮含量的影响,并在单因素实验的基础上,通过正交试验,确定昙花总黄酮的最佳提取工艺.结果表明,乙醇体积分数、提取温度、提取时间以及料液比对昙花总黄酮的含量均有影响;单因素考察结果显示乙醇体积分数为80%,提取温度为80℃,提取时间为4 h,料液比为1∶40(g/m L)条件下昙花总黄酮含量较高;正交试验优化的昙花总黄酮的提取工艺为乙醇体积分数为80%,提取温度为90℃,提取时间为4 h,此条件下昙花总黄酮含量为1.18%.本工艺简单、可行,为昙花的进一步开发利用奠定基础.     

微波萃取法提取豆渣中大豆异黄酮工艺研究

为优化豆渣中大豆异黄酮的提取工艺,以乙醇为溶剂,采用微波辅助萃取法,选取乙醇浓度、提取温度、微波萃取时间、固液比作为考察条件,结果表明,豆渣中大豆异黄酮的最佳提取工艺为:乙醇体积分数80%,提取温度60℃,微波萃取时间40 min,固液比1∶10～1∶12之间。     

微波-超声波协同辅助夏枯草中熊果酸的提取工艺研究

文章采用微波-超声波协同辅助夏枯草中熊果酸的提取,对乙醇浓度、液固比、提取温度和提取时间进行了研究。结果表明,熊果酸提取的最佳工艺条件是:乙醇的体积分数为95%、液固比为12∶1、提取温度为70℃、提取时间为240 s,此条件下的提取率为98.84%。     

枸杞总黄酮提取工艺优化及不同年份枸杞总黄酮含量测定

为探究枸杞贮藏过程中总黄酮含量变化规律,以枸杞总黄酮提取率为指标,采用单因素实验研究浸提温度、乙醇体积分数、料液比和提取时间4因素对枸杞总黄酮提取率的影响,设计正交试验优化提取工艺,并在优化条件下研究不同年份枸杞总黄酮含量及理化指标间的差异.结果发现,最佳提取工艺参数即浸提温度70℃、乙醇体积分数80%、料液比1∶15 g/mL、提取时间2.5 h、提取次数为2次.在此条件下,发现枸杞总黄酮含量随贮藏时间延长而呈现下降的变化趋势,这为枸杞总黄酮的开发利用和快速鉴别枸杞新陈提供理论依据.     

桔皮类黄酮乙醇提取工艺研究

研究了桔皮类黄酮的乙醇提取工艺,以桔皮类黄酮质量分数为考察指标,通过单因素和正交试验,考察提取温度、乙醇质量浓度、固液比、提取时间对类黄酮质量分数的影响,结果确定最佳提取工艺条件为:提取温度70℃,固液比1∶25,乙醇质量分数70%,提取时间2 h.在最佳提取条件下,提取率可达22.03%.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

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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