SPE-MHPLC法测定金银花中绿原酸的研究

研究了用固相萃取-微柱高效液相色谱法(SPE-MHPLC)测定金银花中的绿原酸.金银花样品中的绿原酸用80%的甲醇加热回流提取,提取液用Sep-Pak-C18固相萃取小柱预分离脱脂,以W aters X terraTMRP18(1.0×50mm,2.5μm)微柱为固定相,甲醇-乙酸溶液(1%)为流动相,用紫外二级管矩阵检测器检测.回收率在96%-102%之间,RSD在1.5%-2.2%之间.该方法用于金银花样品中绿原酸的测定,结果满意.     

微柱高效液相色谱法测定贯叶连翘中的芸香苷

研究了用微柱高效液相色谱法测定贯叶连翘中芸香苷.样品中的芸香苷用80%甲醇加热回流提取,以WatersXterraTMRP18(1 0×30mm,2 5μm)色谱微柱为固定相,1%的醋酸和甲醇为流动相,在该色谱条件下,样品芸香苷在1 0min内可达到基线分离,用紫外二极管矩阵检测器检测,方法可用于贯叶连翘中的芸香苷的测定.     

用固相萃取和微柱高效液相色谱法快速测定枸杞样品中的类胡萝卜素

研究了固相萃取富集和预分离,微柱高效液相色谱快速测定枸杞样品中类胡萝卜素的方法;枸杞样品中的类胡萝卜素用Waters Sep-Pak C18固相萃取小柱预分离,然后以Waters XterraTMRP18(1.0×50 mm,2.5μm)微柱为固定相,甲醇-四氢呋喃(80:20,V/V)为流动相分离,用二极管矩阵检测器检测,检测波长为450 nm,枸杞样品中的几种类胡萝卜素在5 min内可达到基线分离。方法标准回收率为95~103%,RSD为1.9~2.6%。用该方法测定了几种枸杞样品中的类胡萝卜素,结果令人满意。     

微柱高效液相色谱法测定Cu(HQ)2和HQ

研究了用微柱高效液相色谱法测定8-羟基喹啉铜中的8-羟基喹啉(HQ)和8-羟基喹啉铜[Cu(HQ)2]的方法,8-羟基喹啉铜样品用甲醇溶解,然后以WatersXterraTMRP18(1.0×50mm,2.5μm)微柱为固定相,60%的甲醇(内含0.05moL/LpH值为4.0的醋酸-醋酸钠缓冲盐)为流动相分离,用紫外二极管矩阵检测器检测测定,方法标准回收率在99-102%,相对标准偏差在0.58-0.65%之间,结果满意.     

微柱高效液相色谱法测定阿奇霉素含量

研究了用固相萃取富集和预分离,微柱高效液相色谱快速测定阿奇霉素的方法;样品中的阿奇霉素用W atersX terraTMRP18反相固相萃取小柱预分离和富集,然后以W aters X terraTMRP18(1.0×50 mm,2.5 mm)微柱为固定相,四氢吡咯-醋酸缓冲溶液(pH 11.0)和乙腈(50∶50,v/v)为流动相分离,用二极管矩阵检测器检测,检测波长为215 nm,样品中的阿奇霉素在5.0 m in内可达到基线分离.方法标准回收率为90%~101%,RSD为0.38%~2.8%.用该方法测定了注射液和尿样品中的阿奇霉素,结果令人满意.     

RP-HPLC法测定复方岩白菜素片中岩白菜素的含量

建立了复方岩白菜素片中岩白菜素含量测定的反相高效液相色谱法.采用色谱柱Diamonsil C18(5μm,4.6 mm×250 mm),柱温为30℃;流动相为V(乙腈)∶V(水)=15∶85;流速为1.0 m L·min-1;检测波长272 nm.研究结果表明:岩白菜素在28.32~226.56μg/ml的范围内呈良好的线性关系,样品平均回收率为100.86%,RSD=0.89%.该方法操作简便,快速,具有良好的稳定性和重复性,适用于复方岩白菜素片中岩白菜素含量测定.     

固相萃取-高效液相色谱法测定杜鹃中的几类黄酮

通过固相萃取-高效液相色谱法测定了杜鹃中的几类黄酮.用80%甲醇回流提取杜鹃样品中的黄酮,提取液经W aters Sep-Park-C18固相萃取小柱预分离,以W aters X terraTMC18(150×4.6 mm,φ3.5μm)色谱柱为固定相,甲醇-水为流动相梯度洗脱,杜鹃中的几类黄酮得以分离和测定.新方法标准回收率95%~105%,RSD为1.6%~2.5%.     

鬼灯檠属及近缘植物中岩白菜素的HPLC定量分析

目的:比较鬼灯檠属及近缘植物中岩白菜素的含量,为资源利用提供依据.方法:色谱条件采用ZORBAX SB-C18色谱柱(4.6mm×150mm,5μm),流动相为甲醇-水(含0.1%磷酸)17:83,检测波长275nm,流速0.80ml/min,柱温30℃.结果:岩白菜素线性范围在3.05～10.98μg范围内呈良好的线性关系,r=0.999 91,平均回收率为101.17%(n=5),s=1.56%.结论:本次实验说明这些在民间作为岩陀使用的植物中都含有岩白菜素,且种间差异大.     

岩白菜素在兔子体内药物代谢动力学

 建立一种简单快速测定兔子血浆中岩白菜素含量的高效液相色谱法,并对岩白菜素在兔子体内的药代动力学过程进行了研究.将血浆样品经乙酸乙酯提取后,进行高效液相色谱法分析,以甲醇-水(体积比22:78)为流动相,测定不同采血时间点兔子血浆中的岩白菜素浓度,采用PKS程序拟合出岩白菜素在兔子体内代谢的动力学参数.实验结果表明,岩白菜素在兔子血浆中的代谢过程符合二室开放模型特征,是一种吸收快、消除快的药物.该测定方法操作简便、快速,实验得到的一系列药代动力学参数,为岩白菜素的临床用药提供依据.     

反相高效液相色谱法测定消毒剂中三氯羟基二苯醚

本文用HPLC法对消毒剂中三氯羟基二苯醚含量进行测定,样品经80%甲醇水溶液稀释,用ODS C18柱进行分离,以甲醇水(8020)为流动相,紫外280nm检测,回收率在98%～102%,相对标准偏差(CV)为0.47%,最低检出浓度为7.0 mg/kg,线性范围为5～200μgmL,相关系数为0.999.     

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