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 共查询到19条相似文献,搜索用时 125 毫秒
1.
赵留鹏  张树永 《大学化学》2016,31(11):83-88
归纳了文献中导出圆形毛细管液柱上升高度计算公式的方法;明确指出了采用受力分析导出毛细上升高度公式时,对伸展力进行简化处理的原理以及其中所隐含的基本假设;从流体力学角度对液柱上升速率和高度进行了讨论.分3种情况对液柱在方形毛细管中上升的现象进行了系统分析,得出了一些重要的结论.  相似文献   

2.
较详细地讨论了附加压力与分散系统稳定性间的关系,指出分散相附加压力的降低是分散系统趋向稳定的根本原因。以乳状液为例,附加压力降低不仅减少了液滴间相互碰撞的概率,而且更重要的是,它与液滴表面形成牢固的保护膜密切相关。只有当液滴的附加压力趋近0时,分散系统才达到热力学上稳定的状态,此时乳状液已变成了微乳状液。上述讨论也基本适用于固/液分散系统。  相似文献   

3.
王安  孙毓庆 《色谱》1993,11(3):128-130
〕在HP-5890型气相色谱仪改装成单炉双载气串联毛细管气相色谱系统上,根据操作参数PiPa和Po求算死时间、相对滞留因子和系统容量因子,建立ks-2回归方程,进行定性分析。对酯类、酮类及醇类不同类型化合物定性分析结果与单柱实测值进行比较,在OV-1和PEG-20M柱上最大误差分别是2和5个Kovats指数单位。  相似文献   

4.
谢敏杰  冯钰锜  达世禄 《色谱》2000,18(6):503-507
 毛细管电色谱是近年发展起来的高效、高选择性的微分离技术。与一般的毛细管电泳和使用ODS反相填料的毛细管电色谱相比 ,含离子涂层柱的毛细管电泳和毛细管电色谱能提供较大且可控的电渗流 ,便于拓宽分离对象 ,优化分离条件。对使用含离子涂层柱的毛细管电泳和电色谱的特点、发展和应用状况进行了综述。  相似文献   

5.
糖类的毛细管电泳及芯片毛细管电泳   总被引:6,自引:0,他引:6  
毛秀丽  林炳承 《色谱》2001,19(4):309-313
 糖类化合物在生物体内发挥多方面的作用。糖研究的复杂性在于其结构的复杂多变。高效毛细管电泳作为一种快速、高效的分离分析手段已广泛应用于糖的研究。芯片毛细管电泳是近几年来发展起来的新的分析技术 ,并已经在生命科学的研究中得到较广泛的应用。就各种糖类化合物的毛细管电泳的分析策略、检测条件及糖类化合物的芯片毛细管电泳进行了阐述 ,共 4 8篇。  相似文献   

6.
毛细管电泳研究和应用的最新进展   总被引:5,自引:1,他引:5  
以作者所在实验室近期工作为主线,结合第五届国际毛细管电泳学术报告会(1993.1.25-28,Orlando,USA)的有关背景情况,介绍了近年来高性能毛细管电泳在应用、技术和理论方面研究工作的进展。  相似文献   

7.
李启  张婷  方群 《分析化学》2013,(5):650-657
概述了基于短毛细管的高速毛细管电泳系统的研究进展。重点介绍了适用于基于短毛细管的高速毛细管电泳系统的各种进样方法及其在生物分离分析领域的应用,包括光门进样、流动门进样、电动进样、自发进样、流体动力进样和扩散进样等方法。  相似文献   

8.
在毛细管电泳的胶束电动色谱(MEKC)模式下,采用压力辅助电动进样(PAEKI)的进样方式在线富集4种酚类雌激素(PEs)。对影响PAEKI的进样电压、进样时间等进行考察,并与传统的压力进样比较。结果表明,在最优的PAEKI条件下(-9 kV,0.3 psi(约2.1 kPa),0.4 min),4种PEs在7 min内基线分离,线性关系良好,相关系数(r)大于0.9936,己烷雌酚和双烯雌酚的线性范围为0.05~5 mg/L、双酚A和己烯雌酚的线性范围为0.1~10 mg/L;检出限(S/N=3)为0.0071~0.017 mg/L,富集倍数为11~15。使用该MEKC-PAEKI法对自来水和湖水水样进行测定,得到定量限(S/N=10)分别为0.029~0.064 mg/L和0.033~0.079 mg/L;加标回收率为75.6%~110.1%,相对标准偏差(n=5)为4.6%~11.8%。PAEKI不需要使用其他试剂,只需对电泳仪的参数进行适当调整即可实现对分析物的在线富集,简单、快速、自动化程度高。  相似文献   

9.
糖类的高效毛细管电泳   总被引:7,自引:0,他引:7  
高效毛细管电泳以其快速、高效、简便、高分辨率、样品和溶剂消耗少及易于仪器化等优点正成为生物活性分子分离和分析工作中的一个重要工具。介绍了作为四大基本生命物质之一的糖类化合物的高效毛细管电泳研究进展,包括CZE、CGE、MECC和CITP等四种分离模式以及直接紫外/荧光法、间接紫外/荧光法、示差法、电化学法和质谱法等五种检测方式。并简要介绍HPCE在单糖、寡糖和多糖分离与分析中的应用,展望了HPCE用于单个细胞中糖类组分的研究前景。  相似文献   

10.
毛细管电泳与芯片毛细管电泳的双检测技术   总被引:1,自引:0,他引:1  
综述了毛细管电泳和芯片毛细管电泳的3种双检测技术,包括荧光-散射等光学双检测技术、安培-非接触电导等电化学双检测技术和荧光-非接触电导等光电联用双检测技术.介绍了3种双检测方法的仪器的检测原理及应用,并展望了双检测技术的发展前景.引用文献54篇.  相似文献   

11.
The differential version of the method of capillary rise has been used to measure the capillary constant and calculate the surface tension of methane-nitrogen solutions. Experiments have been conducted in the temperature range from 95 to 170 K at pressures up to 4 MPa. Experimental data on surface tension have been compared with the results of calculations by thermodynamic models. Equations are given which describe the dependence of the capillary constant of a solution on its temperature and composition.  相似文献   

12.
Excess molar volume, changes of refractive index, and surface tension deviations of binary mixtures of 1,2-ethanediol+1-propanol or 1-butanol have been determined at 293.15, 298.15, 303.15, and 308.15 K. The experimental data of refractive indices and surface tensions were compared with those predicted by different empirical expressions.  相似文献   

13.
As a continuation of our studies of the excess functions of binary systems containing acetonitrile (1−x)–amines (x) mixtures, the molar heat capacity, Cp, and excess molar heat capacity, Cp E, of acetonitrile + diethylamine or sec-butylamine mixtures have been determined as a function of composition at 288.15, 293.15, 298.15 and 303.15 K at atmospheric pressure using a modified 1455 PARR solution calorimeter. The excess heat capacity data are positive for both systems over the whole composition range. The experimental data on the excess molar heat capacity are discussed in terms of the influence of the magnitude of the experimental excess molar enthalpy, H E, over the curve shaped for the experimental Cp E data, molecular interactions in the mixtures, isomeric effect of the amines and modeling of Cp E data.  相似文献   

14.
表面活性剂/聚合物体系具有多种工业用途,尤其在提高石油采收率方面具有广泛的应用前景。另外,此类体系中存在复杂而特殊的相互作用.因此,聚合物/表面活性剂体系物理化学性质的研究具有十分重要的理论和实际意义.文献中对此方面的研究已有不少报导[1-6].1967年,Jones  相似文献   

15.
The traditional formulation of capillary theory does not explicitly contain the general dimension equation that is valid also for its own scalar variables. Its introduction enables the experimentally determinable physical properties to be interpreted. These properties individually characterize the bulk phases generating the layers that enter into the capillary interaction. Not only empirically known approximate relationships, such as the van der Waals and Walden equations, the Watson’s formula, and the Cailletet–Mathias rule, can be derived through them, but also new findings can be made. By extending the formulation with a new type of parameters, the relationships of temperature, density-dependence, etc. may be directly generated. The individual concept, which differs from the traditional theory in only one extra power law, is compatible with other capillarity methods based on material structure and outperforms the heuristic power of the traditional theory in terms of operability.  相似文献   

16.
本研究采用毛细管电泳与电色谱两种方法,在优化分离条件下将3,5-二甲基吡唑新型硝化抑制剂与土壤样品中的其它成分进行分离。通过比较其检出限及标准工作曲线证明:两种方法定量准确度相近,但毛细管电色谱法在实际样品的分离中具有明显的优势,是进一步研究该新产品的较好的分离分析方法。  相似文献   

17.
A new experimental method to directly measure the film tension of black foam films is developed on the basis of the Laplace equation. The method allows the determination of the tension of curved (spherical) films with various radii and capillary pressures. Measurements with Newton black films from sodium dodecyl sulphate aqueous solution have been carried out. The results show that in the studied range of curvature radii (70 ÷ 360 m) the film tension does not depend on the curvature and the capillary pressure.  相似文献   

18.
The surface tension of an aqueous solution of a hexadecyltrimethylammonium bromide (HTAB) and dodecyltrimethylammonium bromide (DTAB) mixture was measured as a function of the total molality and the composition of DTAB at 298.15 K under atmospheric pressure. The phase diagrams of adsorption and micelle formation were constructed and the excess Gibbs energy was evaluated by analyzing the phase diagrams thermodynamically. Both the excess Gibbs energy in the adsorbed film and the excess surface area are negative; therefore the mutual interaction between HTAB and DTAB is said to be stronger than that between the same species and is enhanced with increasing adsorption. By combining the results with those obtained in previous studies, we claimed that DTAB molecules can use effectively the space among the hydrocarbon chains of HTAB molecules and their polar head groups take a staggered arrangement at the surface so as to reduce the electrostatic repulsion. Consequently the dispersion force between hydrophobic chains becomes stronger. Furthermore, the comparison of the excess Gibbs energy in the adsorbed film with that in the micelle shows that the staggered arrangement of molecules is not necessary in the spherical micelle.  相似文献   

19.
New experimental data of densities and surface tensions are presented for the binary mixtures of the ionic liquid 1-ethyl-3- methyl imidazolium nitrate([EMIM]NO3) with methanol and ethanol.Measurements were performed at 298.15 K and atmospheric pressure,covering the whole composition range.Excess molar volumes VE and the surface tension deviations Sy have been determined.For the excess molar volumes of binary mixture,there is a region of negative VE at low IL mole fraction,passing through a minimum and then VE increases and becomes positive,showing maximum at higher IL mole fraction.It is shown that the surface tension deviations Sy of[EMIM]NO3 + methanol system are positive but those of[EMIM]NO3 + ethanol system are negative over the entire mole fraction range.  相似文献   

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