英红九号红茶HPLC指纹图谱的建立与分析

采用高效液相色谱法（HPLC）对大叶种红茶英红九号的春、夏、秋三季茶产品进行测定,对所得HPLC色谱图中的相对保留时间、相对峰面积、共有峰进行了分析。结果表明,HPLC色谱法具有良好的精密度,各样品色谱峰的相对保留时间稳定,可作为指纹图谱的相对时间,并确定了7个共有峰。以各色谱峰的峰面积为因子,用相关系数、聚类分析等方法构建了数字化的英红九号红茶HPLC指纹图谱。在本研究的实验范围内,该方法在区分不同季节生产的英红九号红茶、以及英红九号红茶与其他品种红茶的差异性等方面具有可行性。     

浅谈不同开封时间的乙酸铵对糖精钠、山梨酸保留时间的影响

研究不同开封时间的乙酸铵对糖精钠、山梨酸保留时间的影响。采用高效液相色谱法,以二极管阵列检测器(DAD)检测,色谱柱为Waters Sunfine C18(250mm×4.6mm,5μm),流动相甲醇-乙酸铵溶液(5:95),柱温35℃,用不同时间开封的同一厂家的乙酸铵配置乙酸铵溶液进行试验,糖精钠和山梨酸的相对保留时间和出峰顺序发生改变。不同开封时间的乙酸铵对糖精钠、山梨酸保留时间和出峰顺序有影响,进而影响峰形及峰纯度。     

何首乌特征图谱分析方法研究

本文阐述了建立何首乌药材色谱定性分析方法。采用HPLC测定法,色谱柱phnomenex C18,4.6×250 mm,5μm;流动相:甲醇-水梯度洗脱;流速1.2 ml/min;检测波长280 nm;柱温40℃。对何首乌有效部位进行指纹图谱定性分析,从18个批次不同产地何首乌药材的指纹图谱中可检出4个相对位置稳定的色谱峰,作为定性鉴别的指标峰。利用何首乌药材指纹图谱可以作为对何首乌药材的定性分析和质量控制。     

半夏药材紫外指纹图谱共有峰率和变异峰率双指标序列分析

目的:采用共有峰率和变异峰率双指标序列分析法分析不同产地半夏药材紫外指纹图谱。方法:以石油醚、氯仿、无水乙醇、水4种溶剂分别提取半夏药材不同极性区间成分,测定其紫外指纹图谱,研究各样品之间的异同。结果:采用该方法可以对不同产地半夏药材进行区分。结论:本方法操作简单,应用范围广,为半夏药材质量评价提供了简便的方法。     

"一测多评"法同步定量、定性分析 垂盆草药材中3种有效成分

为建立以1种对照品同时检测垂盆草中槲皮素、山柰素、异鼠李素3个成分的"一测多评"方法,随机从药材市场收集12批垂盆草样品,以外标法测定其中各有效成分的含量;以槲皮素为内标物,确定山柰素、异鼠李素的相对校正因子及相对保留时间;另取8批样品,对实验结果加以验证.得到山柰素、异鼠李素的相对校正因子分别为0.960、0.918,山柰素、异鼠李素的相对保留时间分别为1.85、2.15.验证试验表明"一测多评"法检测结果与外标法相比无明显差异,利用"一测多评"法同时检测垂盆草药材中槲皮素、山柰素、异鼠李素3个成分含量所得结果准确度高,具有良好的重现性、稳定性和精密度,"一测多评"法可用于垂盆草药材的质量控制.     

罗汉果甜苷HPLC指纹图谱的研究

该文旨在研究并建立罗汉果甜苷的指纹图谱,采用高效液相色谱法对广西不同产地不同品种的罗汉果进行分析,色谱条件为:色谱柱Lichrospher NH,250×4.6mm,流动相:乙腈和异丙醇水溶液(体积比75∶2.5∶22.5),流速为1.0ml/min,检测波长为205nm.该研究建立的分析方法有较好的重复性,不同产地不同品种的罗汉果色谱峰相对保留时间一致,为加强罗汉果的质量控制提供实验基础.     

走胆草高效液相指纹图谱的研究

目的:建立抗肝炎药走胆草药材的HPLC指纹图谱.方法:反相高效液相色谱法,流动相为甲醇-水(含0.1%磷酸),梯度洗脱,流速为1.0ml·min-1,检测波长为270nm,柱温为30℃.结果:精密度、重复性、稳定性试验中共有峰的峰面积小于5%、保留时间的RSD值均小于3%;不同产地的走胆草的相似度大于0.90.结论:该方法简便、可靠,可作为走胆草药材的质量标准.     

快速测定废水中苯胺、硝基苯方法研究

选用分析纯正己烷,对兰州石化公司化肥厂苯胺装置苯胺废水塔(T-601)馏出口废水、硝基苯废水塔(T-401)馏出口废水、污水池废水、污水处理废水中的苯胺、硝基苯进行萃取,采用大口径毛细管柱气相色谱分离技术,对萃取液中苯胺、硝基苯进行分离,用FID检测器进行检测,用标样中苯胺、硝基苯的保留时间与样品中色谱峰保留时间相对照的方法定性,峰面积标准曲线法定量,进行废水中苯胺、硝基苯气相色谱法快速测定的方法研究,方法最低检测下限为:苯胺0.91mg/L、硝基苯0.98mg/L,分析时间为15min,分析结果的相对标准偏差RSD4.0%。     

红景天药材指纹图谱的研究

用高效液相色谱法建立了红景天药材的色谱指纹图谱.固定相采用ODS-C18(4.6mm×250mm×5μm)色谱柱,流动相为乙腈-0.08%磷酸水溶液梯度洗脱,检测波长为278nm,体积流量为1.0mL/min.结果表明,11个红景天样品共有10个共有峰,可作为鉴定红景天药材的主要依据.该方法简便快捷,可为红景天药材的鉴定、质量标准的建立及控制提供一定的参考.     

应用HPLC色谱技术进行柃属植物化学分类学研究

利用高效液相色谱(HPLC)技术对24种1变种柃属植物28份样品的化学成分进行检测,并以各样品中色谱峰的相对保留时间对柃属植物的特征化学成分进行标记,最终统计到23个特征色谱峰用于化学分类研究。结果显示,柃属植物色谱峰在种内稳定出现,在种间则呈现多样性,可用于物种的鉴别。为进一步探讨种间亲缘关系及部分种的具体分类学地位,研究同时还采用UPGMA法和NJ法对色谱峰进行聚类分析,并根据两种聚类树型图讨论了化学成分的分类学意义。研究结果表明HPLC色谱技术具有快捷性、直观性和重现好的特点,可作为一种理想的标记用于柃属植物的分类鉴定。此外,本研究还能为柃属进一步的资源利用研究提供重要的参考。     

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.     

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