枸杞黄酮提取方法的比较研究

以宁夏枸杞总黄酮提取率为指标,利用正交设计优化实验条件,比较研究了微波提取与常用提取方法（回流提取法、超声波提取法）所得枸杞总黄酮的提取率,优选了枸杞总黄酮的提取方法．与回流法相比,超声波和微波提取法都能明显缩短提取时间,有效提高枸杞黄酮的提取率,特别是微波提取能显著提高枸杞黄酮的提取效率．微波提取的最佳实验条件为温度100℃,固液比1：30,火力3,提取时间20min．结果表明,用微波提取法提取宁夏枸杞总黄酮具有高效、省时的特点,值得在中药提取中推广应用．     

微波辅助法提取啤酒废酵母多糖的工艺研究

运用微波辅助技术,优选啤酒废酵母多糖的最佳提取工艺,以多糖提取率作为考察指标,采用单因素分析和正交试验对啤酒废酵母多糖的提取工艺条件进行优化。啤酒废酵母多糖最佳提取工艺条件为:微波时间为10min,微波功率为540W,浸润时间为1h,多糖得率为13.27%。与常规水提取法相比,微波辅助提取法具有提取时间短、效率高、节约能源的优点。     

响应面法-微波辅助萃取仙鹤草多糖工艺优化

通过响应面分析法对微波辅助萃取仙鹤草多糖工艺进行优化,最终确定仙鹤草多糖的实验室最佳提取工艺条件为:微波功率400 W、微波时间111 s、提取温度87.3℃、液料比70.17 m L/g,且此条件下仙鹤草多糖提取率为4.54%.经验证性实验可知,此最佳提取工艺条件下的多糖提取率与响应面分析模型所得最优值有较好的拟合度,具有实际应用价值,且相对常规水煮法而言,微波辅助萃取法有提取时间短,提取温度低,提取率高等优点.     

海西黑枸杞多糖酶法提取工艺研究及其体外抗氧化性分析

以青海海西黑枸杞为原料,用酶法辅助提取其中的多糖。对比果胶酶、木瓜蛋白酶和纤维素酶的辅助提取效果,以料液比、加酶量、酶解时间和酶解温度为因素进行单因素实验,考察其对黑枸杞多糖提取率的影响,利用响应面法进一步优化黑枸杞多糖提取工艺参数,并对提取的多糖进行体外抗氧化性分析。结果表明:(1)果胶酶辅助提取黑枸杞多糖的效果最好,最佳提取条件为料液比1∶35(g∶mL)、加酶量0.02 g、酶解时间60 min、酶解温度30℃,提取率达到最大值26.60%,与模型方程理论预测值26.90%相对误差为1.12%;(2)海西黑枸杞多糖对DPPH自由基和超氧阴离子自由基具有较强的清除作用。     

微波强化提取大枣多糖的研究

通过正交试验确定了微波法强化提取大枣多糖的实验条件，并与常规的水浴提取法作了比较。结果表明，工艺条件为浸泡时间60min、pH6．5，微波处理5min，多糖浸提率为5．26％。与传统溶剂提取法相比，采用溶剂浸泡与微波提取集成技术提取大枣中的多糖具有明显的提取效果。     

桑叶多糖的提取工艺研究

研究了水浸提法提取桑叶多糖的工艺条件,比较了超声法、酶法和微波法等不同的前处理方法对桑叶多糖提取效率的影响．结果表明：（1）水浸提法提取桑叶多糖的较优方案为：温度80℃、时间1h、料液比1：40,桑叶多糖的得率约为11．50％．（2）超声法辅助提取桑叶多糖的较优方案为：超声功率300W,超声处理10min,之后水浸提多糖的得率为12．25％．（3）纤维素酶为桑叶多糖的最佳酶提取剂,其酶解的较优方案为：酶用量为桑叶量的1．5％,酶解时间2h,酶解温度50℃,酶处理后水提多糖得率为12．49％．（4）微波辐射时间以8min为宜,微波法辅助提取多糖得率为11．68％．（5）比较4种处理方法提取桑叶多糖的得率,依次为：酶辅助法〉超声辅助法〉微波辅助法〉水浸提法,综合考虑成本、工作效率等因素,以超声法前处理、水浸提桑叶多糖得率较高．     

微波辅助提取米糠多糖的工艺

以脱脂挤压米糠为原料,采用微波辅助法提取米糠多糖,并与传统热水浸提方法进行比较,通过考察料液比、微波辐射时间以及微波功率三个因素,设计正交试验,得出微波辅助提取米糠多糖的优化工艺条件为：料液比1：10,微波辐射时间为2min,微波炉功率400W．传统热水浸提米糠多糖提取率为2．02％,纯度为68．53％,微波辅助提取多糖的提取率为2．76％,纯度为72．47％．与传统热水浸提方法相比较,微波辅助法的米糠多糖提取率和纯度分别提高了36．6％和5．7％．微波辅助法提取可以显著提高米糠多糖的提取效率,但对其理化性质并无影响．     

超声法提取枸杞多糖工艺优化

采用超声法提取枸杞多糖,考察了料液比、超声功率、超声时间和提取温度四个因素对枸杞多糖提取率的影响。结果最佳提取工艺条件为:料液比1∶50、超声功率60 W、超声时间15 min,提取温度90℃。     

枸杞蜂花粉多糖超声波提取工艺优化及抗氧化活性分析

为确定枸杞蜂花粉多糖的最佳提取工艺,采用Box-Behnken试验设计,以提取得率为考察指标,优化超声辅助提取枸杞蜂花粉多糖的工艺,并研究了优化提取工艺条件下多糖的体外抗氧化活性。实验结果表明,超声辅助提取枸杞蜂花粉多糖的优化工艺为:料液比(g/mL)1∶25、提取温度90℃、超声功率240W、超声时间20min,多糖的得率为0.89%~0.91%,与预测值结果相符,表明模型拟合良好、优化工艺可行。体外抗氧化活性实验表明,枸杞蜂花粉多糖有较好的DPPH自由基和ABTS⁺自由基清除能力,但FRAP值较低。研究结果可为枸杞蜂花粉多糖的开发利用提供一定依据。     

微波辅助提取溪黄草多糖的工艺研究

以多糖提取率为评价指标,采用分光光度法测定溪黄草多糖的含量,在单因素试验的基础上,通过正交优化考察了微波功率、微波时间、料液比对多糖提取率的影响．结果表明,各因素对溪黄草多糖提取率的影响顺序由大到小依次为：微波功率,微波时间,料液比．最佳提取条件为：微波功率为中火,微波时间为25min,料液比为1：15（g／mL）．在此条件下．溪黄草多糖的提取率为15．32％．与传统的索氏提取法相比,微波提取法具有提取效率高、节省时间、操作简便、易工业化等优点．     

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