金银花中绿原酸的微波辅助提取

采用微波辅助提取金银花中的绿原酸。考察了溶剂种类及浓度、提取时间、液固比、溶剂PH、提取次数等对绿原酸得率的影响;结合正交实验设计确定了绿原酸的最优提取工艺条件：液固比15,φ=0．4的乙醇溶液提取2次,每次60s。将优化后的微波提取结果与其他方法比较,结果表明：微波法具有操作简单、快速高效、节能环保等优点。     

微波法提取红景天苷的工艺研究

以红景天为原料,以水为溶剂研究微波提取红景天苷的最佳工艺参数。通过试验,分别考察了固液比、微波功率、微波处理时间、提取次数等因素对提取效果的影响,探讨了微波提取的机理。在红景天苷初提液的澄清处理中选择有机絮凝剂、无机絮凝剂和高速离心技术相结合的方法,其澄清效果明显优于单一絮凝剂。     

玄参新鲜根和干燥根总DNA提取方法的比较研究

用十二烷基磺酸钠法分别提取玄参新鲜根及干燥根的DNA.电泳结果显示,从玄参新鲜根中可提取到完整DNA,而从"发汗"后的玄参干燥根中提取的DNA已降解.使用紫外分光光度法对新鲜根中提取的DNA进行纯度鉴定,A260/A280为1.83.结果表明,所采用的十二烷基磺酸钠法可经济高效地从玄参根部提取到高质量的DNA.     

微波法提取淫羊藿中淫羊藿苷工艺研究

采用微波辅助提取淫羊藿中淫羊藿苷,以淫羊藿苷为考察目标,系统考察了提取溶剂、微波功率、提取时间、料液比四个因素对提取效果的影响.采用正交实验对提取工艺进行初步研究,确定最佳工艺条件为70%乙醇,微波功率400W,提取时间40分钟,料液比1:40.     

微波辅助提取墨旱莲总黄酮的工艺优化

采用微波辅助提取墨旱莲中的总黄酮。以总黄酮得率为指标,考察微波辐射时间、液固比、溶剂pH、提取级数等因素对得率的影响,确定了总黄酮的最佳提取工艺条件:以去离子水为溶剂,液固比(V/m)=25 mL/g,微波提取210 s,提取2次,此时墨旱莲总黄酮得率为1.42%,而常规水提取的时间为60 min,得率1.24%,故微波辅助提取法高效,省时。     

微波提取胡椒碱的工艺研究

运用微波法对胡椒中胡椒碱进行提取，并采用HPLC对胡椒碱的含量进行测定，考察提取时间、提取温度、料液比、乙醇浓度及微波功率对胡椒碱收率的影响．实验结果表明：在提取时间为60min、提取温度为55℃、料液比为80：50、乙醇体积分数为80％及微波功率为500W的条件下，微波辅助提取胡椒碱的效果最佳，胡椒碱收率可达4．12...     

微波辅助提取双孢蘑菇柄中多糖的工艺研究

为提高双孢蘑菇柄中多糖的提取得率,采用微波辅助法提取双孢蘑菇柄中多糖.分别对微波功率、微波处理时间、液料比、提取次数4个因素进行单因素实验和正交试验,并通过极差、方差分析,对提取过程中显著影响提取率的因素进行了统计分析.结果表明:微波辅助提取多糖的较佳工艺条件为微波强度60%、辐射时间6min、液料比1:12、提取次数4次,该工艺条件下提取多糖提取率为1.64%.     

高效液相色谱法测定苦玄参药材中的苦玄参苷ⅠA含量

采用Agilent ZORBAX Eclipse XDB C8 色谱柱(4.6×150mm,5μm),以乙腈-0.5%醋酸(32:68)为流动相,流速1ml·min-1,检测波长264nm,建立高效液相色谱法(HPLC),测定广西梧州大坡种植基地和龙州县种植的苦玄参药材的茎、叶中苦玄参苷ⅠA的含量.实验结果显示,苦玄参苷ⅠA在2.28～11.4μg范围内线性良好,平均加样回收率为101.1%RSD=2.4%(n=5),梧州大坡种植基地和龙州县种植的苦玄参药材中苦玄参苷ⅠA在茎、叶中的平均含量分别为0.10%,0.31%,0.11%,0.58%.本方法简便、快速,重复性好,可实际用于苦玄参药材中苦玄参苷ⅠA含量测定.     

微波辅助提取百香果中绿原酸的工艺研究

采用微波辅助提取与高效液相色谱技术,探索百香果中绿原酸的提取工艺.采用L9(34)正交实验法,考察了微波功率、微波提取时间、乙醇溶剂浓度以及料液比等因素对绿原酸提取得率的影响.研究得出微波辅助提取百香果中绿原酸的最佳工艺条件是:微波功率为中高火,微波时间2 min,乙醇溶剂体积分数80%,料液比1∶10,在这些条件下百香果中绿源酸提取得率为0.053%.     

中药枳壳中柚皮苷和橙皮苷的提取方法研究

目的:采用正交设计法,对枳壳中的柚皮苷和新橙皮苷的提取方法和提取工艺参数进行优化。方法:通过水浴回流、索氏提取、超声辅助提取、微波炉辅助提取四种提取方法的比较,其中水浴回流提取法采用L9(33)正交实验以提取溶剂、时间、温度为因素,每个因素选3个水平,以枳壳中的柚皮苷和新橙皮苷的提取率来确定最优化的提取方法和提取条件。结果:水浴回流提取的优化条件是:溶剂为80%乙醇,温度为60℃,时间为40min.索氏提取优选95%乙醇,超声提取优选甲醇作溶剂。微波提取的最优化条件是,80%乙醇作溶剂,微波萃取仪功率400W,提取时间10min,温度40℃.结论:水浴回流提取法适用于作为生产制剂的提取,超声和微波提取法宜用于药物成分分析的提取。     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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