共查询到19条相似文献,搜索用时 54 毫秒
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基于电驱动特性与离子交换膜的选择透过性,构建了新型、无损伤的脱氧核糖核酸(DNA)捕获浓缩装置。以λ-DNA为模型化合物,探究其在自组装装置中的富集特性,优化了实验条件,对浓缩液进行凝胶电泳实验以考察DNA是否变性,并进行聚合酶链反应,以证明本方法回收的DNA可供进一步的生物分析。结果表明:本装置在低电压条件下能够无损伤地捕获DNA,浓缩液可用于进一步的生物分析,DNA的富集倍数达62倍,回收率达46%。本方法操作简便,避免使用大量有机试剂,微型化可与生物芯片联用,在DNA萃取、纯化与浓缩领域有较大的应用空间。 相似文献
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介绍一种真空薄膜浓缩方法 总被引:3,自引:0,他引:3
介绍一种真空薄膜浓缩方法袁珂胡润淮(河南中医学院化学教研室450003)浓缩是实验室及生产中经常使用的一种工艺操作,在化学化工、医药卫生、食品工业及化妆品工业等许多行业中用途甚广。尤其是对天然产物化学成分的研究,一般都要经过提取、浓缩、分离等过程,因... 相似文献
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真空薄膜浓缩装置的研制及应用研究 总被引:14,自引:0,他引:14
介绍了真空薄膜浓缩装置的构造、特征、工作原理及使用方法,并将真空薄膜浓缩法与旋转薄膜浓缩法的工作效率及对热敏性成分含量的影响进行了比较研究。结果表明,两法相比,前者具有仪器容量大、浓缩速度快、浓缩液受热时间短、操作简单及工作效率高等优点。 相似文献
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一种利用离子交换膜研制的电化学氧传感器 总被引:5,自引:0,他引:5
利用聚苯乙烯阴离子交换膜研制的金为催化剂,采用碱性体系的新型控制电位电解型氧传感克服了以往电化学氧传感器的缺点,具有响应时间快、稳定性好、噪声低、本底电流小、温度系数低等优点。 相似文献
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荷电膜的膜电位研究进展 总被引:1,自引:0,他引:1
膜电位的测定是表征荷电膜的传递现象的重要参数之一。本文简要介绍了膜电位理论基础,包括T. M. S.理论和不可逆热力学理论。分别阐述了关于离子交换膜、双极膜、两性膜以及复合膜的膜电位的最新进展,并提出今后的发展方向。 相似文献
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基于电迁移率差异而分离的新型聚焦电泳技术①陈东英林华水周勇亮毛秉伟谢兆雄卓向东田昭武*(固体表面物理化学国家重点实验室及化学系厦门大学厦门361005)毛细管区带电泳已成为十几年来发展最快的分离分析技术.Hjertén于1967年在玻璃管中进行了自由... 相似文献
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基于移动中和界面(MNB)概念,研制了一种基于电泳酸碱滴定(EABT)的新装置.其核心技术是在电泳管中建立MNB,通过对电泳管中的MNB在一定时间内迁移距离的测定,推测酸或碱的浓度.EABT实验表明:HCl浓度的对数值与MNB移动距离存在线性关系.此关系可用于检测未知酸的浓度;不同酸碱指示剂对EABT方法没有明显影响,这能有效避免在容量分析法中不同指示剂对判定终点断滴所造成的误差;EABT具有良好的精密性和稳定性,日内差和日间差的RSD值分别小于1.6%和3.8%. 相似文献
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This article deals with a semi‐analytical study on the electrophoresis of charged spherical rigid colloid by considering the effects of relaxation and ion size. The particle surface is taken to be either hydrophilic or hydrophobic in nature. In order to consider the ion size effect we have invoked the Carnahan and Starling model (J. Chem. Phys. 1969, 51, 635‐636). The mathematical model is based on Stokes equation for fluid flow, modified Boltzmann equation for spatial distribution of ionic species and Poisson equation for electric potential. We adopt a linear perturbation technique under a weak electric field assumption. An iterative numerical technique in employed to solve the coupled set of perturbed equations. We have validated the numerically obtained electrophoretic mobility with the corresponding analytical solution derived under low potential limit. Going beyond the widely employed Debye‐Hückel linearization, we have presented the results for a wide range of surface charge density, electrolyte concentration, and slip length to Debye length ratio. We have also identified several interesting features including occurrence of local maxima and minima in the mobility for critical choice of pertinent parameters. 相似文献
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In this paper, a new solvent-free route for preparing proton-conductive membranes is proposed. Flexible and fiber-supported polymer electrolyte membranes, as potential proton exchange membranes, were readily obtained by in situ polymerization of a homogenous solution that consisted of bromomethylated poly(2,6-dimethyl-1,4-phenylene oxide) (BPPO, polymer)–monomer mixtures of styrene (ST) and divinylbenzene (DVB), which was pre-cast onto SEFAR PETEX fibers. Factors such as the components of the casting solution and the sulfonation time, were fully investigated. The membrane structure and components were confirmed by FTIR-ATR spectra and SEM-EDXA images, and the thermal stability was examined via TGA and DrTGA. The membrane exhibited a proton conductivity of about 0.07 S/cm at 100% humidity and at room temperature, which is close to that of Nafion 117 at identical conditions (around 0.08 S/cm), whereas its thickness (about 120 μm) was less than that of Nafion 117. The tensile strength and the elongation at the break of the membrane were 31.2 MPa and 71%, respectively, which are several times higher than those of Nafion (about 6.16 MPa tensile strength and 36% elongation ratio). The dimensional change ratio of the membrane between the wet and dry states was below 3%, which is much lower than that of Nafion 117. The membrane showed a high thermal stability up to 400 °C. The method can be applied to other compatible systems of (aromatic) polymers and (aromatic) monomers. 相似文献
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Disclosed is a method of preparing hypophosphorous acid comprising contacting an insoluble anode with an aqueous solution of hypophosphite anions and applying a direct current through the insoluble anode to a cathode in electrical contact with the aqueous solution to generate H+ ions in the aqueous solution thereby forming a hypophosphorous acid solution. The process is simple,low cost and high efficient, which can be tied into an existing process for producing sodium hypophosphite wherein the product of sodium hypophosphite process is used as a starting material in the hypophosphorous acid process. 相似文献
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ELECTRODIALYTIC PRODUCTION OF HYPOPHOSPHOROUS ACID 总被引:2,自引:0,他引:2
CHENG Jianzhong ZHANG Yingzhe ZHANG Baogui** ZHANG Zhengpu College of Environmental Science & Engineering Nankai University Tianjin Institute of Polymer Chemistry Nankai University Tianjin 《Chinese Journal of Reactive Polymers》2001,(1)
1. INTRODUCTIONHypophosphorous acid (H3PO2) also known as phosphinic acid, is currently a staple article of commerce which is sold by various companies for purposes such as the manufacture of hypophosphite salts, as well as to prevent the discoloration of phosphate esters, in esterification catalysts, and for the manufacture of cooling water treatment chemicals. It is also sold for use in metal finishing procedures, as a reducing agent for electroless plating, and as a sealer for phosphat… 相似文献
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A new ion exchange membrane based on polyvinylidene fluoride (PVDF) and sulfonated poly(styrene-
divinylbenzene) was prepared by in-situ polymerization. The incorporation of sulfonic groups into the polyvinylidene fluoride composite membrane was confirmed by infrared spectroscopy (IR), ion exchange capacity (IEC) and energy dispersive X-ray analysis (EDAX). Area resistance, IEC and water uptake of the treated membrane were evaluated. When 20% of the crosslinked membrane was sulfonated at 80°C for 22 h, the PVDF ion exchange membrane can attain 0.8 Ω·cm2area resistance in NaCl aqueous solution at 25℃, IEC is as high as 2.43 millimoles per gram of the wet membrane. The
hydrophilicity of PVDF membrane is also significantly improved after treatment. When 60% of crosslinked membrane was sulfonated at 80 ℃ for 6 h, water uptake of the treated membrane can attain 64.7%. 相似文献