离体快繁扯根菜总黄酮提取及抗菌活性研究

采用L9(34)正交实验方法、考察提取法与水浴提取法中乙醇浓度(A),作用时间(B),温度/功率(c),料液比(D)4个因素对总黄酮提取量的影响,筛选最佳提取工艺;以此优化工艺分析不同种类及浓度的激素对再生苗总黄酮含量的影响,分析提取物的不同菌体的抑制效果.结果表明超声波提取法优于水浴法,最佳参数固液比为110,在80%的乙醇中按50%的功率处理30min;源于添加0.5 mg.L-1Kt的MS培养基再生的扯根菜中的总黄酮含量最大,为3.28%;提取物对金黄色葡萄球菌具有最大的抑制效果.添加激素的提取物对金黄色葡萄球菌和铜绿假单胞菌的抑菌效果具有促进作用.     

超声波提取黄芪中总黄酮工艺研究

研究比较了超声波法、微波法、乙醇提取法等工艺提取黄芪总黄酮的效果,得出超声波法提取黄芪总黄酮的工艺最佳．以提取温度、提取时间、料液比、乙醇体积分数为考察因素,黄芪总黄酮提取率为考察指标,采用止交试验法优化黄良总黄酮提取工艺．结果表明,最佳工艺条件为：超声波提取温度为65C、提取时间30min、料液比为1：15（g／mL）、乙醇体积分数为65％,总黄酮的提取率为0．418％,是微波提取法的1．31倍,乙醇提取的1．69倍．     

白子菜总黄酮含量的测定

白子菜样品经45％乙醇提取后，以芦丁为标准品，用聚酰胺吸附-硝酸铝显色法于510nm处测定总黄酮含量．结果表明，白子菜植株总黄酮质量分数为1．43％，叶为1．16％，茎为2．60％，根为4．28％．研究结果可为利用白子菜生产黄酮类药用成分提供科学依据．     

超声波提取抱茎苦荬菜总黄酮工艺的研究

以抱茎苦荬菜全草为原料,在单因素实验基础上,以乙醇浓度、超声时间、超声功率、料液比4因素进行正交实验,优化超声波提取抱茎苦荬菜内总黄酮物质的提取工艺.在实验影响因素中,影响程度从大到小依次为超声波功率＞乙醇浓度＞料液比＞超声提取时间.实验结果表明,抱茎苦荬菜全草中黄酮类物质的最佳提取条件为:7.72 mol/L乙醇,料液比1:20,超声功率400 W,在50℃提取60 min,连续提取2次,总黄酮得率高达1.102%.     

超声波提取光石韦叶中总黄酮工艺研究

为了优选光石韦叶中总黄酮类化合物的超声波提取工艺,以芦丁为对照品,乙醇浓度、料液比、超声时间、萃取温度为影响因素设计正交实验,采用紫外分光光度法测定总黄酮得率。最终确定光石韦叶片总黄酮超声波提取最佳工艺为:乙醇浓度50%,料液比1∶40,时间40min,温度70℃。在此工艺条件下,超声波提取总黄酮平均得率为16.16%,由此可见,超声波辅助提取法可以加快提取速度,提高提取效率。     

超声波辅助法提取紫苏叶总黄酮的研究

采用超声波辅助法来提取紫苏叶总黄酮,通过研究提取剂乙醇浓度、料液比、超声波处理时间、浸提水浴温度等单因素及正交试验对紫苏叶总黄酮提取率的影响,确定了超声波辅助提取紫苏叶中总黄酮的工艺条件.结果表明,在浸提液为30%的乙醇、料液比1∶40、超声波（80 Hz、200 W）处理70 min、80 ℃水浴温度下提取2次,得到的紫苏叶粗提液总黄酮含量最高,提取率为21.81 mg/g.     

葛根总黄酮成分的超声提取及抗氧化作用

采用超声波方法从葛根中提取总黄酮，用正交法确定了超声波方法提取总黄酮的最佳工艺条件为：乙醇浓度70％，超声波提取25min，提取次数3次，温度25℃；同时测定了在最佳条件下提取的葛根总黄酮对DDPH自由基的清除率，证实葛根总黄酮具有一定的抗氧化作用，是一种天然的抗氧化剂。     

马鞭草中总黄酮的超声波辅助提取及其抗氧化活性研究

目的研究马鞭草总黄酮的超声波辅助提取方法。方法通过单因素试验和正交试验,探讨影响超声波辅助提取马鞭草总黄酮的优化工艺条件,并对马鞭草中黄酮类化合物的抗氧化活进行测定。结果马鞭草中总黄酮的最佳超声提取工艺条件为乙醇溶液体积分数70％、固液比1：40（g／mL）、超声功率500W、超声辅助提取温度70℃条件下提取20min,在此条件下提取率可达2．87％。影响马鞭草中总黄酮提取效果的主次因素为：固液比〉超声波功率〉提取温度〉乙醇体积分数。马鞭草黄酮类化合物具有清除羟自由基、超氧阴离子自由基的作用,其清除效果在一定范围内随着黄酮类化合物质量浓度的增加而增强。结论运用超声波辅助提取法从马鞭草中提取黄酮类化合物可以加快提取速度,提高提取效率,方法简单,结果准确,重现性好,是提取马鞭草总黄酮的有效途径。     

超声波强化提取牡丹花黄酮

采用超声波技术对牡丹花黄酮提取进行强化，选择超声频率、乙醇浓度、超声时间、物料比为因素进行正交实验，优选出超声提取最佳工艺：即以70％的乙醇，料液比为1：20，在频率为22kHz的超声波下处理10min，提取率可达91．5％。具有提取效率高，提取时间短，温度低的优点。     

显脉旋覆花根中总黄酮提取方法的研究

以显脉旋覆花根为试验材料,用乙醇和甲醇为提取剂,采用浸提法分别对显脉旋覆花根中总黄酮进行提取,并用紫外分光光度法进行了测定.结果表明:乙醇70%,甲醇体积分数50%,浸提时间均为24 h时,总黄酮的提取效果较好,乙醇和甲醇提取的总黄酮得率分别为2.33%和1.84%,乙醇的提取效果优于甲醇,总黄酮测定方法平均回收率为99.89%,相对标准偏差RSD为0.89%,结果可靠.     

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