蒽环类碱性药物在亲水作用色谱中保留机理的研究

采用以高纯硅胶为色谱柱,水-有机溶剂为流动相的亲水作用色谱模式,通过改变流动相中有机溶剂类型及浓度、酸类型、缓冲液pH值及离子强度,探讨了蒽环类碱性药物在该色谱模式下的保留机理.结果表明,在所考察条件下,溶质的保留机理主要为吸附及离子交换混合保留机理.     

氟化表面活性剂修饰硅胶色谱固定相制备及分离性能

以1-乙烯基咪唑和1-碘-1H,1H,2H,2H-全氟癸烷为原料合成了含氟表面活性剂——碘化1-乙烯基-3-全氟辛基乙基咪唑(VIMF).进一步将VIMF作为可聚合单体,利用巯基-烯点击反应,制备了VIMF键合硅胶色谱固定相(Sil-VIMF).采用傅里叶变换红外光谱和热重分析对Sil-VIMF固定相材料进行表征,结果证明了其成功制备.保留机制考察结果表明,Sil-VIMF固定相具有亲水作用色谱保留机制.色谱分离性能研究结果表明,Sil-VIMF固定相可实现酰胺类、核苷和核碱基类、苯胺类物质的良好分离,其柱效可达79 200 N/m.进一步将Sil-VIMF固定相用于胃癌细胞膜脂提取物的分离分析,可实现胃癌细胞膜中磷脂酰胆碱和磷脂酰乙醇胺的有效分离分析,显示了良好的应用潜能.     

表阿霉素在硅胶柱上不可逆吸附行为的研究

亲水作用色谱分离表阿霉素时，在中性及弱酸性条件下，样品在硅胶柱上呈现不可逆吸附平衡过程．对影响不可逆吸附的因素如缓冲液的pH值、离子强度、有机溶剂的类型及流动相中水的含量进行了探讨，推断这种现象是由于溶质离子与固定相表面极少数的强活性硅羟基作用所致．不可逆吸附是在一定条件下产生的，可通过改变洗脱条件减小。     

单糖柱前PMP衍生HPLC测定方法探讨

从PMP萃取酸度、萃取次数探讨了柱前PMP衍生方法对单糖-PMP衍生物的影响,并从流动相比例、缓冲液pH值、缓冲盐浓度三个方面对单糖柱前衍生HPLC的分离效果进行了优化研究.结果表明:单糖进行PMP衍生后,用HCl中和至pH为7.0,能最大限度避免单糖-PMP衍生产物的损失;使用三氯甲烷萃取PMP三次时,能在除去PMP的情况下避免单糖-PMP衍生产物的损失;降低流动相中有机相的比例或提高缓冲液的pH值,有利于色谱峰分离度的提高;提高缓冲盐浓度,有利于保持色谱峰的对称性.     

C_(60)-g-(乙二胺基)丙基键合硅胶填充柱毛细管电色谱

建立C60-g-(乙二胺基)丙基键合硅胶填充柱毛细管电色谱法。研究操作条件如流动相组成、pH值对柱电渗流的影响.结果表明填充柱与流动相之间存在着快速平衡,可建立稳定的电色谱方法,并且填充柱可以在pH 2.5-7的范围内提供稳定的电渗流,有利于电色谱分离。     

一种新型两性离子交换毛细管液相色谱整体柱

利用甲基丙烯酸和2-二甲基乙基胺甲基丙烯酸酯为功能单体,乙二醇二甲基丙烯酸酯为交联剂,通过在石英毛细管内原位聚合制备了1种新型两性离子交换液相色谱整体(MAA-EDMA-DAMA)柱.整体固定相表面正、负电荷密度受流动相pH影响,故通过调节流动相pH值可实现阴阳离子交换模式相互转换.当流动相pH6.0时,此整体柱表现出典型阴离子交换作用机理,聚合整体柱对一些无机阴离子如BrO3-、NO2-、Br-和NO3-有很好的选择性;当流动相pH7.0时,该整体柱表现出阳离子交换作用机理,对对甲苯胺、邻苯二胺、对氯苯胺、对硝基苯胺表现出高的选择性;当流动相中乙腈含量小于40%时,疏水作用和离子交换作用对有机离子的保留均有影响,为提高分离的选择性创造有利条件.     

含酸性基团温度敏感色谱材料的制备及其在氨基酸分离中的应用

用自由基聚合法制备了分别含有聚(N-异丙基丙烯酰胺/2-丙烯酰胺基-2-甲基丙磺酸)和聚(异丙基丙烯酰胺/甲基丙烯酸异丁酯/丙烯酸)的2种酸性温敏色谱填料.用热失重和元素分析表征了接枝率.用HPLC研究了异硫氰酸苯酯衍生化丙氨酸、缬氨酸、苯丙氨酸、色氨酸、精氨酸、亮氨酸等6种氨基酸的色谱保留行为.结果显示,采用纯水相为流动相,仅通过控制柱温即可实现分离,证明被分离物的色谱保留性质随温度的改变而变化,制得的色谱填料具有温度敏感性.     

亲水作用毛细管电色谱检测分析苷类药物的技术研究

基于多面体寡聚硅倍半氧烷-甲基丙烯酸羟乙酯poly(POSS-MA-co-HEMA)有机硅胶杂化整体柱,建立了典型苷类药物(连翘苷、豆腐果苷、紫丁香苷、天麻素)的亲水作用毛细管电色谱检测技术。考察了苷类药物的亲水作用,优化了流动相乙腈比例、缓冲液浓度、缓冲溶液pH、分离电压以及反压阀压力的影响,在最优条件(流动相为2 mmol/L磷酸三乙胺缓冲液(乙腈含量90%,pH=7.0),分离电压-8 kV、柱压力750 psi),4种苷类药物在10 min内得到了基线分离。连翘苷、豆腐果苷、紫丁香苷和天麻素线性范围分别为10~200 μg/mL、25~200 μg/mL、15~200 μg/mL和25~200 μg/mL, 检测限为1.5~8.0 μg/mL。应用于血清模拟样品分析,平均回收率为95.6%~99.1%,相对标准偏差小于3.3%。     

C60-γ-(乙二胺基)丙基键合硅胶填充柱毛细管电色谱

建立C60-γ-（乙二胺基）丙基键合硅胶填充柱毛细管电色谱法，研究操作条件如流动相组成，pH值对柱电渗流的影响，结果表明填充柱与流动相之间存在着快速平衡，可建立稳定的电色谱方法，并且填充柱可以在pH2.5-7的范围内提供稳定的电渗流，有利于电色谱分离。     

高效液相色谱手性拆分中的配体交换色谱手性固定相

综述了高效液相色谱配体交换色谱手性固定相的发展、制备及其在手性拆分中的应用,讨论了洗速、进样量、中心金属离子及其浓度、流动相pH值、柱温、有机改性剂等对对映体分离的影响,阐述了对手性识别机理的认识。     

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