高效毛细管线性聚丙烯酰胺凝胶电泳柱的制备、柱性能表征及操作条件考察

发展一种简便快速的线性聚丙烯酰胺毛细管凝胶电泳（ＣＧＥ）柱的新型制备方法，用于分离Ｐｏｌｙ ｄＡ（４０～６０）和双链ＤＮＡ，柱效达 ６百万理论板／米。提出“筛分能力”作为 ＣＧＥ柱评价指标，对样品迁移行为随操作条件的变化规律进行考察，为毛细管凝胶电泳的理论研究和实验条件优化奠定了基础。     

高效毛细管线性聚丙烯酰胺凝电泳柱的制备,柱性能表征及操作条件考察

发展一种简便快速的线性丙聚丙烯酰胺毛细管凝胶电泳柱的新型制备方法，用于分离ＰｏｌｙｄＡ（４０－６０）和双链ＤＮＡ，柱效达６百万理论板／米。提出“筛分能力”作为ＣＧＥ柱评价指标，对品迁移行为随操作条件的变化规律进行考察，为毛细管凝胶电泳的理论研究和实验条件优化奠定了基础。     

填充毛细管液相色谱—毛细管气相色谱在线联用分析柴油全组成

采用填充毛细管液相色谱（ＰＣ－ＨＰＬＣ）与毛管气相色谱（ＣＧＣ）在线联用技术分析柴油全组分。半填充硅胶、半填充氨基的ＰＣ－ＨＰＬＣ柱（０．３２ｍｍ ｉ．ｄ）用于样品族分离（烷烃、单环芳烃、双环芳烃、三环芳烃和胶质）。经ＰＣ－ＨＰＬＣ分离后的各族组分（峰体积小于３０μＬ）被依次存放在多位储存接口内，然后分别转入ＧＣ作单个组分定量分析，可得出各族组分的相对含量及烷烃的碳数的正异构分布。该方法是分析柴油     

聚己内酯－聚乙二醇嵌段共聚物Ⅱ．组成、结晶性同降解性间关系

采用ＤＳＣ法测定了新嵌段共聚物聚己内酯（ＰＣＬ）－聚乙二醇（ＰＥＧ）嵌段共聚物（ＰＣＥ）的结晶性，研究了共聚物的结晶性同组成及降解性的关系．结果表明随着共聚物中ＰＥＧ组分的含量和分子量增加，共聚物的结晶性下降，亲水性提高，降解速度加快．     

毛细管区带电泳分析阿片受体和抗独特型抗羟甲芬太尼抗体

应用毛细管区带电泳（ＣＺＥ）分析测定阿片受体、抗独特型抗羟甲芬太尼抗体等生物大分子样品。熔融石英毛细管柱为６０ｃｍ×１００μｍｉ．ｄ．（从进样到检测器长度为５０ｃｍ）,以硼砂－氢氧化钾为缓冲液。结果表明缓冲液的ｐＨ影响ＣＺＥ对阿片受体的分析,当ｐＨ为９．０时分析效果最理想,重现性良好,测得的两个主峰与同批样品进行ＳＤＳ－ＰＡＧＥ分析得到的两个条带相符。用ＣＺＥ分析抗独特型抗羟甲芬太尼抗体（ＩｇＧ）,表明用ＰｒＯｔｅｉｎＡ－Ｓｅｐｈａｒｏｓｅ亲和色谱分离得到部分纯化的ＩｇＧ,迁移时间不同于对照豚鼠的ＩｇＧ。     

无胶筛分毛细管电泳分析几百个碱基对核酸的条件优化

通过正交设计实验综合分析了内充羟丙基甲基纤维素（ＨＰＭＣ）无胶筛分毛细管电泳中的分离场强、ＨＰＭＣ浓度、柱长度和柱内径对核酸分离的影响。结果表明,柱长度越长、柱内径越小、分离场强越小,分离效果越好。考虑实际情况,为能在短时间内使几百个碱基对的核酸得到有效分离,一般选择３７ｃｍ×７５μｍｉ．ｄ．的涂壁毛细管、柱内质量浓度为８ｇ／Ｌ的ＨＰＭＣ、场强为３２４Ｖ／ｃｍ的条件,并在此种条件下分析了ＡｐｏＢ１００基因的低浓度聚合酶链式反应（ＰＣＲ）扩增产物（７１０ｂｐ）。     

毛细管电泳的原理及应用（第三讲）毛细管电泳的柱技术

毛细管电泳的原理及应用（第三讲）毛细管电泳的柱技术王义明,罗国安（清华大学化学系,清华大学生命科学与工程研究院北京１０００８４）关键词毛细管电泳,柱技术１概述毛细管电泳（ＣＥ）的分离和检测过程均在毛细管内完成,所以说毛细管是ＣＥ的核心部件之一。早期对毛细管的研究集中在毛细管直径、长度、形状和材料方面。采用细柱可减少电流及自热,而且能加快散热,以保持高效分离;但会造成进样、检测及清洗上的困难,也不利于对吸附的抑制,故现在一般采用２５～１００μｍ内径的毛细管。     

毛细管区带电泳法研究肾上腺素类药物的手性分离

使用β－环糊精（β－ＣＤ）及β－ＣＤ－羧甲基（ＣＭ－β－ＣＤ）作为手性选择剂,采用毛细管区带电泳法（ＣＺＥ）对去甲肾上腺素、肾上腺素和异丙肾上腺素的手性分离进行了研究。对影响这类药物手性分离的主要因素〔手性选择剂、背景电解质（ＢＧＥ）、分离体系的酸度和温度〕进行了讨论,并对手性识别机理进行了探讨。     

A NOVEL REACTION BETWEEN Ge－Ge AND Fe－Fe BONDS IN COMPLEX （Me_2GeGeMe_2）［（η~5－C_5H_4）Fe（CO）］_2（μ－CO）_2 AND CRYSTAL STRUCTURE OF THE PRODUCT

ＡＮＯＶＥＬＲＥＡＣＴＩＯＮＢＥＴＷＥＥＮＧｅ－ＧｅＡＮＤＦｅ－ＦｅＢＯＮＤＳＩＮＣＯＭＰＬＥＸ（Ｍｅ_２ＧｅＧｅＭｅ_２）［（η~５－Ｃ_５Ｈ_４）Ｆｅ（ＣＯ）］_２（μ－ＣＯ）_２ＡＮＤＣＲＹＳＴＡＬＳＴＲＵＣＴＵＲＥＯＦＴＨＥＰＲＯＤＵＣＴ￥ＸｉｕＴ?..     

毛细管电泳质谱联用技术及其应用

本文介绍了用于毛细管电泳质谱联用仪器的多种接口技术，描述了ＣＺＥ，ＣＩＥＦ，ＣＧＥ，ＭＥＫＣ和ＣＩＴＰ等毛细管电泳技术和四极质谱，离子阱质谱，傅 叶变换离子回旋共振质谱，飞行时间质谱，磁质谱，解吸质谱等联用的现状及发展前景，对近年来ＣＥ－ＭＳ在酶解产物。蛋白质和肽，核苷酸，药物及代谢产物等领域中的应用作了详细述评。     

外部电场下水分子间静电相互作用的分子动力学研究

本文利用分子动力学模拟探讨了不同外电场下,液态水的分子间作用及分子排布的变化. 在不同外电场下,O…O原子间的径向分布函数差别很小,但是单个水分子的偶极矩的取向变化却很大. 当外电场为0时,单个水分子偶极取向的范围很宽（30-150度）. 与此同时,本文给出了局域诱导电场随着位置的变化关系图. 当外加电场增强时,局域的诱导电场强度也随之增加. 由于电场下偶极矩有序性的增加,局域诱导的静电相互作用能显著增加. 计算结果表明,相对介电常数随着电场强度的增加而呈现指数衰减的变化形式. 这一变化趋势可以用来理解不同电化学环境下,静电相互作用和局域诱导电场的变化.     

磁场对316L不锈钢微生物腐蚀行为的影响

采用循环极化、微生物分析法、扫描电镜及表面能谱分析等方法,研究了磁场对316L不锈钢在含硫酸盐还原菌(SRB)的土壤模拟溶液中的腐蚀行为。结果表明,磁场可以抑制SRB的生长;未外加磁场时316L不锈钢表面膜层以局部堆积为主,加有磁场时,局部堆积明显减小,膜层均匀致密的排列于基体表面;无论有或没有外加磁场,316L不锈钢表面均发生钝化膜破裂型点蚀,未外加磁场时的点蚀电位低于加有磁场时的。在相同的浸泡时间,未外加磁场时循环极化滞后环面积明显比加有磁场时的大,说明磁场可以有效抑制316L不锈钢点蚀的形成与发展,降低316L不锈钢的点蚀诱发能力。     

磁场对含稀土铝锂合金断裂特征的影响

以含铈铝锂合金为研究对象，研究了磁场对含稀土铝锂合金时效过程的影响，从断裂特征及微观组织两方面分析了磁场作用规律。实验结果表明：未加磁场时，合金的断裂特征以理断裂为主；扁平晶粒厚度不匀，在磁场作用下，此合金的断裂特征与微观组织发生明显改观，随磁感应强度增强，合金主断裂面上准解理断裂特征减弱，同时二次裂纹增多，分层比较升高；扁平晶粒厚度变薄，尺寸趋于均匀。用少体物理理论，探讨了磁场对含稀土合金原子扩散过程的影响，为进一步研究稀土元素在磁场中的行为及其局域效应提供了一定的实验依据。     

Electroosmotic Flow in Microchannels

The electroosmotic flow induced by an applied electrostatic potential field through microchannels between two parallel plates and a 90 degrees bend is analyzed in this work. A nonlinear, two-dimensional Poisson-Boltzmann equation governing the electrical double-layer field and the Laplace equation governing the electrostatic field distribution in microchannels are numerically solved using a finite-difference method. A body force caused by the interaction between the electrical double-layer field and the applied electrostatic field is included in the full Navier-Stokes equations. The effects of the electrical double-layer field and the applied electrostatic field on the fluid velocity distribution, pressure drop, and skin friction are discussed. A small pressure drop along the parallel plates is detected, although it is always neglected in the literature. Pressure is not a constant across the channel height. The axial velocity profile is no longer flat across the channel height when the Reynolds number is large. A separation bubble is detected near the 90 degrees junction when the Reynolds number is large. Copyright 2001 Academic Press.     

Intrinsic characteristic times in the drift-diffusion problem

The redistribution of impurities in a sample in the shape of a slab filled with an isotropic liquid submitted to an external field is considered. The case in which the impurities are ions dissolved in the liquid, and the external field is an electric field is also investigated. It is shown that the intrinsic time connected with the presence of the electric field is proportional to the drift time. The constant of proportionality is of the order of the ratio between the thermal agitation energy and the electrostatic energy. A closed solution for the time evolution of the density of particles is obtained. The importance of the effect on real situations is investigated. The possible application of these results to nematic samples submitted to an external electric field is discussed.     

Intrinsic characteristic times in the drift-diffusion problem

The redistribution of impurities in a sample in the shape of a slab filled with an isotropic liquid submitted to an external field is considered. The case in which the impurities are ions dissolved in the liquid, and the external field is an electric field is also investigated. It is shown that the intrinsic time connected with the presence of the electric field is proportional to the drift time. The constant of proportionality is of the order of the ratio between the thermal agitation energy and the electrostatic energy. A closed solution for the time evolution of the density of particles is obtained. The importance of the effect on real situations is investigated. The possible application of these results to nematic samples submitted to an external electric field is discussed.     

Periodic structure of spicular magnetic clusters in a magnetic liquid

The behavior of clusters formed by magnetic particles of magnetic liquid placed into a cylindrical capillary tube in magnetic field is described. Spicular clusters are formed from the sediment at the application of a magnetic field. They arrange themselves along the capillary repeating the direction of external magnetic field. Clusters distribute uniformly in the region of a magnetic field maximum. Such a state remains steady with respect to changes of the magnetic field gradient profile in definite limits. The structure of the uniformly ordered clusters is obtained experimentally. The capability of control of the structure period is shown. It is observed that increasing of magnetic field gradient up to the magnitude higher than a certain threshold value results in rearrangement of the clusters row into a multi-row hexagonal structure.     

Dynamic and microscopic X‐ray characterization of a compound chevron layer in electroclinic liquid crystals

The local layer structure of surface stabilized electroclinic liquid crystals has been analysed by time‐resolved synchrotron X‐ray microdiffraction. At a low applied electric field, the initial bookshelf structure starts to respond above a threshold voltage. With a low to medium applied field of triangular form, the layer structure transforms reversibly between the bookshelf (low field) and the compound chevron (high field), in which the vertical and horizontal chevrons alternate along the layer. When the horizontal chevron component appears, a stripe texture can be seen in an optical micrograph. With increasing field, the horizontal chevron becomes a dominant structure while the vertical chevron still remains. The layer spacing changes in correlation with the chevron angle during the field application. At high field, surface molecules partly rearrange, resulting in alignment deterioration at the interface. The layer response time for an a.c. square wave field is of the order of a few µs to ten µs, which is close to the optical response. The appearance of the compound chevron is discussed in conjunction with the anchoring effect.     

Influence of AC Electric Field on Macroscopic Network of Carbon Nanotubes in Polystyrene

CVD‐grown multiwall carbon nanotubes are dispersed in styrene monomer. During the polymerization of styrene, an AC electric field is applied to induce the CNTs to align along the electric field line to form a macroscopic nanotube network in polystyrene matrix. The dielectrophoresis force and the electric field redistribution at the CNTs apexes are responsible for alignment of the CNTs as well as bonding between the CNTs. Parameters such as field strength and nanotube weight fraction are varied. The results indicate that the macroscopic CNTs alignment along electric field direction can be observed only if the AC voltage reaches or is higher than certain values, and the higher the electric field frequency is, the more uniformly the CNTs align along electric field direction. In addition, nanotube concentration also affects the alignment of CNTs. According to the results of this study, the CNTs will align into a developed network in polystyrene matrix under a proper combination of three parameters of the electric field voltage, frequency, and the CNTs concentration.