甘草酸的热回流提取工艺研究

采用热回流提取法,经过粉碎、热回流提取、浓缩、酸沉、过滤等实验过程从甘草中提取粗提甘草酸。以甘草酸的提取率为指标,通过正交实验设计考察乙醇浓度、NaHCO_3添加量、液料比、提取时间和提取温度对甘草酸提取率的影响。结果表明,甘草酸的最佳提取条件为:乙醇浓度60%、NaHCO_3添加量0. 4%、液料比15∶1、提取时间2. 5 h、提取温度60℃。在最佳条件下甘草酸的平均提取率为33. 27%。     

响应面Box-Behnken设计优化超声波辅助法提取甘草总黄酮的工艺研究

以甘草为原料,碱性乙醇溶液为提取剂,采用超声波辅助法提取甘草总黄酮。在单因素试验的基础上,以乙醇浓度、氨水浓度、液固比、超声温度及超声时间为响应变量,甘草总黄酮提取率为响应值,利用Box-Benhnken设计进行响应面分析,确定甘草总黄酮的最佳提取工艺条件。结果表明,甘草总黄酮的最佳提取工艺为：液固比11,氨水体积分数1.0％,乙醇体积分数66％,超声时间20min,超声温度74℃。在该条件下,甘草总黄酮提取率为2.15％。     

葛根中醇溶性总黄酮的提取工艺优化

采用正交试验法,优化醇法提取葛根中黄酮物质的工艺.以葛根素为对照品,采用分光光度法进行测定,以黄酮提取率为考察指标,对影响黄酮提取工艺的因素进行研究.首先,通过单因素试验研究提取温度、提取时间、乙醇浓度和液固比对黄酮提取率的影响,然后,利用正交试验法优化最佳提取工艺条件.结果表明,乙醇浓度对葛根素提取率影响最大,其次分别为提取温度、液固比、提取时间,最佳提取工艺条件为:提取温度80℃、提取时间60 min、乙醇浓度50%和液固比30:1(m L/g),在此条件下,黄酮平均提取率可达91.93%.采用乙醇浸提葛根黄酮是一种经济、快捷、高效的提取方法,具有很好的应用前景.     

响应面法优化蓝花荆芥中总黄酮提取工艺

采用乙醇热浸提法,考察料液比、乙醇浓度、提取温度以及提取时间对藏药蓝花荆芥全草中总黄酮提取率的影响,并结合响应面设计方法,对藏药蓝花荆芥全草中总黄酮提取工艺进行优化。由实验得到蓝花荆芥总黄酮最佳提取工艺为:乙醇体积分数35%,提取温度65℃,提取时间70min,该条件下总黄酮提取率为0.351%。     

响应曲面法优化醇提茶多酚工艺研究

在单因素试验的基础上,利用响应曲面法对茶多酚醇提工艺参数进行优化研究.选择乙醇浓度、提取时间以及提取温度为自变量,茶多酚提取率为响应值,采用Box-Behnken设计方法,研究各自变量及其交互作用对茶多酚提取率的影响.利用Design Expert软件对数据进行回归分析,得到二次多项式回归方程的预测模型.结果表明,茶多酚醇提的优化工艺条件为:乙醇浓度取20%,提取时间30 min,提取温度76℃.在此工艺条件下茶多酚提取率理论值为18.75%.     

从鱼腥草中提取鱼腥草素分离工艺研究

利用溶剂提取法从鱼腥草中提取鱼腥草素．研究了乙醇浓度、固液比、提取时间、提取温度等工艺条件对鱼腥草素提取率的影响,最佳提取工艺条件为:以50%乙醇溶液为溶剂,固液比1:30,温度50℃,时间65min,提取率可达11．0%．     

大麦籽粒总黄酮超声辅助提取工艺的优化

为探究提取大麦籽粒总黄酮的最佳工艺条件,以脱脂大麦粉为原料,采用响应面分析法对超声辅助提取大麦籽粒总黄酮工艺中的乙醇浓度、液固比、超声时间、提取温度四个主要因素进行了优化.结果表明,乙醇浓度和超声时间是影响大麦籽粒总黄酮提取率的主要因素,该提取工艺的最佳条件为:乙醇浓度95%,液固比55mL/g,超声时间22min和提取温度50℃,在此条件下大麦籽粒总黄酮提取率的理论值可达0.80mg/g.     

甘薯茎中黄酮类物质提取工艺

采用乙醇溶液提取甘薯茎中总黄酮,考察了乙醇浓度、温度、固液比、浸取时间对总黄酮提取率的影响.进行了单因素实验设计,得出优化实验条件:乙醇浓度50%,浸取温度80℃,固液比1∶20,浸取时间3 h,总黄酮提取率为74.6%.     

响应面法优化杨梅原花青素提取工艺

为优化杨梅原花青素的提取工艺参数,通过单因素实验,采用响应面法研究乙醇浓度、料液比、提取时间和温度等对杨梅原花青素提取的影响,以原花青素提取率为评价指标,通过Box-Behnken组合,建立杨梅提取的二次回归方程,得到最优提取条件.结果表明,杨梅原花青素提取得率的影响的顺序为:乙醇浓度温度时间料液比;杨梅原花青素的最佳提取工艺条件为:乙醇浓度为92%,提取温度75℃,提取时间57 min,液料比选取25:1(m L/g).该条件下,杨梅原花青素提取率的为30.03 mg/g.     

乙醇-硫酸铵双水相体系提取柠檬渣中总黄酮研究

以低温烘干的柠檬渣为原料,利用乙醇-硫酸铵双水相体系提取柠檬渣中的总黄酮,通过单因素实验和正交实验考察了乙醇浓度、料液比、硫酸铵用量、提取温度和提取时间对提取率的影响,结果表明乙醇体积浓度为60%、料液比为1∶20g/mL、硫酸铵用量为24g、提取温度为55℃、提取时间为30min时,提取率最高.在此条件下进行了5次平行实验,平均提取率可达1.58%,而且实验重现性好.     

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.     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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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