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1.
综述了质谱及其联用技术(如气相色谱-质谱,液相色谱-质谱,毛细管电泳-质谱等)在抗癌药物的分离鉴定、药物代谢产物的研究及药物作用机理方面的应用,总结了其发展潜力。 相似文献
2.
介绍了植物中硒形态分析的意义,植物中硒存在的形式;综述了植物中硒形态分析时,采用的萃取、液相色谱、气相色谱、电泳和毛细管电泳等样品分离技术;电感耦合等离子体质谱、同位素稀释-质谱、电感耦合原子发射光谱及电喷雾质谱分析方法,引用文献51篇. 相似文献
3.
毛细管电色谱作为一种新型微分离分析技术,其分离过程具有多种机理协同作用的特征。对于毛细管电色谱的理论研究不仅要考虑系统的电属性,还要兼顾溶质的两相分配特征。该书系统地阐述了毛细管电色谱的基本理论,讨论了分离过程中影响峰展宽的因素及其规律。基于作者发展的弛豫理论和唯象的输运过程处理方法,阐述了毛细管电色谱中的动力学和热力学问题,分别就不同的分离模式的选择性规律和柱内富集理论与技术、梯度洗脱的溶质输运特征加以说明。该书可作为从事色谱及毛细管电泳、毛细管电色谱理论及应用研究的科技人员和分析化学专业研究生的… 相似文献
4.
毛细管电色谱是近年发展起来的一种新型微分离技术,它整合了毛细管电泳与微径柱液相色谱的优点,通过在填充微细颗粒液相色谱填料的微径柱色谱柱两端施加直流高压电场,达到对痕量复杂生物及化学体系样品良好地分离。该书是作者近年来从事毛细管电色谱领域研究的积累和总结,全面介绍了毛细管电色谱基本原理、分离机理和分离行为,各类毛细管柱的制备方法和性能评价,加压毛细管电色谱仪的研制及应用实例。该书可供化学和生物专业研究生和科研人员参考阅读。 相似文献
5.
综述了毛细管电泳与电喷雾质谱联用的接口技术、分离模式及其在蛋白质分析领域中的应用,特别是毛细管等电聚焦与电喷雾质谱联用在蛋白质组学中研究进展。 相似文献
6.
毛细管电色谱是近年发展起来的一种新型微分离技术,它整合了毛细管电泳与微径柱液相色谱的优点,通过在填充微细颗粒液相色谱填料的微径柱色谱柱两端施加直流高压电场,达到对痕量复杂生物及化学体系样品良好地分离。该书是作者近年来从事毛细管电色谱领域研究的积累和总结,全面介绍了毛细管电色谱基本原理、分离机理和分离行为,各类毛细管柱的制备方法和性能评价,加压毛细管电色谱仪的研制及应用实例。该书可供化学和生物专业研究生和科研人员参考阅读。 相似文献
7.
毛细管电色谱是近年发展起来的一种新型微分离技术,它整合了毛细管电泳与微径柱液相色谱的优点,通过在填充微细颗粒液相色谱填料的微径柱色谱柱两端施加直流高压电场,达到对痕量复杂生物及化学体系样品良好地分离。该书是作者近年来从事毛细管电色谱领域研究的积累和总结,全面介绍了毛细管电色谱基本原理、分离机理和分离行为,各类毛细管柱的制备方法和性能评价,加压毛细管电色谱仪的研制及应用实例。该书可供化学和生物专业研究生和科研人员参考阅读。 相似文献
8.
毛细管电色谱作为一种新型微分离分析技术,其分离过程具有多种机理协同作用的特征。对于毛细管电色谱的理论研究不仅要考虑系统的电属性,还要兼顾溶质的两相分配特征。该书系统地阐述了毛细管电色谱的基本理论,讨论了分离过程中影响峰展宽的因素及其规律。基于作者发展的弛豫理 相似文献
9.
本实验以自制毛细管电色谱整体柱为手性分离柱,应用毛细管电色谱-电喷雾-飞行时间/质谱(CECESI-TOF/MS)联用技术,通过优化CEC分离条件和MS检测条件分离分析得到两种β2-受体激动剂药物。实验结果表明两种β2-受体激动剂药物盐酸克伦特罗和盐酸班布特罗在优化条件下均能达到基线分离,分离度分别为2.31和1.83,为该类药物的手性分离提供了一种新思路。 相似文献
10.
毛细管电色谱作为一种新型微分离分析技术,其分离过程具有多种机理协同作用的特征。对于毛细管电色谱的理论研究不仅要考虑系统的电属性。还要兼顾溶质的两相分配特征。该书系统地阐述了毛细管电色谱的基本理论,讨论了分离过程中影响峰展宽的因素及其规律。基于作者发展的弛豫理论和唯象的输运过程处理方法,阐述了毛细管电色谱中的动力学和热力学问题,分别就不同的分离模式的选择性规律和柱内富集理论与技术、梯度洗脱的溶质输运特征加以说明。 相似文献
11.
Closo-B nH n−2(CO) 2 ( n = 5–12), isolobal analogues of closo-C 2B n−2H n, have been investigated at the B3LYP/6-311+G **density functional level of theory. The most stable isomers of closo-B nH n−2(CO) 2 are similar to those of closo-C 2B n−2H n in geometric patterns apart from closo-B 6H 4(CO) 2, and closo-B nH n−2(CO) 2 is much less strained than closo-C 2B n−2H n. Energetic analysis identifies closo-B 6H 4(CO) 2, closo-B 12H 10(CO) 2 and closo-B 10H 8(CO) 2 to be most stable, of which the latter two cages have been prepared experimentally. On the basis of the negative and rather large nucleus independent chemical shifts (NICS), closo-B nH n−2(CO) 2 are aromatic. To aid further experimental study, the CO stretching frequencies have been computed. 相似文献
12.
在流动余辉装置上, 利用N 2空心阴极放电制备活性氮, 研究了活性氮与溴代烷烃(CHBr 3、CH 2Br 2、C 2H 5Br、C 4H 9Br) 反应的化学发光.上述所有反应中, 在550~750 nm波段均观察到了较强的NBr ( b1Σ+→X3Σ-)跃迁发射谱. 同时在活性氮与CHBr3和CH2Br2的反应中, 在流动管下游还观察到了CN (A2π, B2π→X2Σ+)的发射谱. 验证性的实验表明, 激发态NBr (b1Σ+)是由二步过程形成: N(4S)与溴代烷烃反应生成NBr (X3Σ-), 再通过N2 (A 3Σu+)分子能量转移到激发态NBr (b1Σ+); 而激发态的CN是通过N(4S) + CBr→CN(A, B) + Br过程形成的. 相似文献
14.
Excess molar enthalpies HE and excess molar volumes VE have been measured, as a function of mole fraction x1, at 298.15 K and atmospheric pressure for the five liquid mixtures ( x11,4-C 6H 4F 2 + x2n-C lH 2l+2), l = 7, 8, 10, 12 and 16. In addition, HE and excess molar heat capacities CPE at constant pressure have been determined for the two liquid mixtures ( x1C 6F 6 + x2n-C lH 2l+2), l = 7 and 14, at the same temperature and pressure. The instruments used were flow microcalorimeters of the Picker design (the HE version was equipped with separators) and a vibrating-tube densimeter, respectively. The excess enthalpies of the five difluorobenzene mixtures are all positive and quite large; they increase with increasing chain length l of the n-alkane from HE(x1 = 0.5)/(J mol−1) = 1050 for l = 7 to 1359 for l = 16. The corresponding excess volumes VE are all positive and also increase with increasing l: VE(x1 = 0.5)/(cm3 mol−1) = 0.650 for l = 7 and 1.080 for l = 16. Interestingly, the excess enthalphies of the corresponding mixtures with hexafluorobenzene are only about 5% larger, whereas the excess volumes of (x1C6F6 + x2n-ClH2l+2) are roughly twice as large as those of their counterparts in the series containing 1,4-C6H4F2. Specifically, at 298.15 K HE(x1 = 0.5)/(J mol−1) = 1119 for (x1C6F6 + x2n-C7H16) and 1324 for (x1C6F6 + x2n-C14H30), and for the same mixtures VE(x1 = 0.5)/(cm3 mol−1) = 1.882 and 2.093, respectively. The excess heat capacities for both systems are negative and of about the same magnitude as the excess heat capacities of mixtures of fluorobenzene with the same n-alkanes (Roux et al., 1984): CPE(x1 = 0.5)/(J K−1 mol−1) = −1.18 for (x1C6F6 + x2n-C7H16), and −2.25 for (x1C6F6 + x2n-C14H30). The curve CPE vs. (x1 for x1C6F6 + x2n-C14H30) shows a sort of “hump” for x1 0.5, which is presumed to indicate emerging W-shape composition dependence at lower temperatures. 相似文献
15.
以5,5-二甲基-1-吡咯啉-N-氧化物(DMPO)为自由基捕获剂,分别以去离子水和二甲基亚砜(DMSO)为溶剂,利用电子自旋共振(ESR)方法对UV、O 3、TiO 2/O 3、TiO 2/UV/O 2、UV/O 3和TiO 2/UV/O 3这6种体系中形成的羟基自由基(·OH)和超氧阴离子自由基(·O 2-)进行了检测,同时考察了反应时间、催化剂投量以及体系溶解氧对TiO 2/UV/O 3体系形成·OH和·O 2-的影响.结果显示,在纳米TiO 2光催化体系中加入臭氧,能显著增加反应体系中·OH和·O 2-自由基的生成量,6种体系中DMPO-·OH和DMPO-·O 2-加合物的ESR波谱峰信号强度分别为:TiO 2/UV/O 3>TiO 2/UV/O 2>UV/O 3>UV>TiO 2/O 3>O 3和TiO 2/UV/O 3≈TiO 2/UV/O 2>TiO 2/O 3>UV>UV/O 3>O 3,在TiO 2/UV/O 3体系中成功监测到·O 3-自由基的存在. 相似文献
16.
A series of Me nAg 0.3Mo 0.5P 0.3O y (Me=Cu, Zn, Mn, W, Ce, Pr, Nd) and Ag 0.3Mo 0.5P 0.3O x catalysts were prepared. The addition of Ce to Ag 0.3Mo 0.5P 0.3O x catalysts improved the catalytic performance in selective oxidation of propane to acrolein, and Ce 0.1Ag 0.3Mo 0.5P 0.3O x catalysts showed the highest acrolein selectivity (28.7%) and yield (4.4%). The physicochemical properties of Ag 0.3Mo 0.5P 0.3O x and Ce nAg 0.3Mo 0.5P 0.3O x ( n=0.1–0.5) catalysts have been comparatively characterized by BET, XRD, H 2-TPR, XPS, EPR and C 3H 8(C 3H 6)-TPD. Significant differences in physicochemical properties between Ag 0.3Mo 0.5P 0.3O x and Ce doped Ag 0.3Mo 0.5P 0.3O x catalysts have been observed, which is due to the formation of the redox cycle (Ce 3++Mo 6+Ce 4++Mo 5+) in the Ce nAg 0.3Mo 0.5P 0.3O y catalyst. Such effect modified the reducibility, the concentration of Mo 5+, the activation of propane and the transformation of possible intermediate propene to acroelin, which in return greatly influenced the catalytic performance of Ce doped Ag 0.3Mo 0.5P 0.3O x catalysts in selective oxidation of propane to acroelin. The proper addition of Ce to Ag 0.3Mo 0.5P 0.3O x catalyst improved the acrolein selectivity and yield. 相似文献
17.
The syntheses of the 1,3,5-trimethyl- and tri- tert-butyl-1,3,5-triazacyclohexane-supported imido complexes [M(NR)(R′ 3tach)Cl 2] (M = Ti or Zr (NMR only); R = Bu t or 2,6-C 6H 3Pr i2; R′ = Me or Bu t) are reported, along with that of the thermally robust dibenzyl derivative [Ti(NBu t)(Me 3tach)(CH 2Ph) 2]. The tert-butylimido ligand in [Ti(NBu t)(Me 3tach)Cl 2] undergoes exchange with ArNH 2 (Ar = 4-C 6H 4Me or 2,6-C 6H 4Me or 2,6-C 6H 3Pr i2) to form the corresponding arylimides [Ti(NAr)(Me 3tach)Cl 2]. The Me 3tach ring in [Ti(NR)(Me 3tach)Cl 2] undergoes slow exchange with Bu t3tach or Me 3tacn (1,4,7-trimethyl-1,4,7-triazacyclononane) to give the ring-exchanged products [Ti(NR)(Bu t3tach)Cl 2] and [Ti(NR)(Me 3tacn)Cl 2], respectively. The complexes [Ti(NR)(Me 3tach)X 2] (R = Bu t or 2,6-C 6H 3Pr i2; X = Cl or CH 2Ph) exhibit room-temperature dynamic NMR behaviour via an unusual trigonal twist of the facially coordinated Me 3tach ligand, and the activation parameters for these processes have been measured and are discussed. The X-ray structures of [Ti(NR)(Bu t3tach)Cl 2] (R = Bu t or 2,6-C 6H 3Pr i2) and [Ti(NBu t)(Me 3tach)(X) 2] [X= Cl or CH 2Ph) are reported. Me 3tach and Bu t3tach = 1,3,5-trimethyl- and tri- tert-butyl-1,3,5-triazacyclohexane, respectively. 相似文献
18.
The enthalpy change for anabolism is needed to model the growth/respiration relation in plants. If all CO 2 production is assigned to catabolism, the anabolic reaction becomes C substrate→C products+ xO 2 with an enthalpy change, Δ Hb. Four methods are proposed for determining Δ Hb: (a) From the difference in the heats of combustion of substrate and anabolic products (i.e. newly grown tissue). (b) From the composition of newly grown tissue and application of Thornton’s rule. (c) From independently measured values of the specific growth rate, RSG, and of the product ( RSG Δ Hb). The product ( RSG Δ Hb) equals (−Δ HCO2RCO2− Rq) where RCO2 is the specific rate of CO 2 production by respiration, Δ HCO2 is the heat of combustion of respiratory substrate per mole of CO 2 and Rq is the specific metabolic heat rate. Δ Hb is then calculated as the ratio ( RSG Δ Hb)/ RSG. (d) From (Δ Hb=−( Rq/ RCO2+Δ HCO2) [(1−)/] where is the substrate carbon conversion efficiency obtained from a total carbon balance. The first three methods have been tested and compared on oat seedlings and the last on corn seedlings. Δ Hb values from all four methods are in reasonable agreement despite the different assumptions involved. 相似文献
19.
采用浸渍提拉法制得TiO 2,ZnO,Fe 2O 3,ZnO/TiO 2,TiO 2/ZnO,Fe 2O 3/TiO 2和TiO 2/Fe 2O 3石英玻璃基底负载膜.光催化降解亚甲基蓝实验表明,TiO 2和ZnO具有良好的光催化活性,Fe 2O 3活性较差.但形成异质结后,TiO 2和Fe 2O 3的光催化降解能力发生明显的变化.用254nm紫外光光照后,TiO 2,ZnO和Fe 2O 3等3种氧化物膜与水的接触角均有不同程度的降低,TiO 2表现出超亲水性,ZnO/TiO 2和Fe 2O 3/TiO 2膜与水的接触角小于对应的单纯ZnO和Fe 2O 3膜与水的接触角,其中Fe 2O 3/TiO 2表面出现超亲水性.瞬态光电导谱的少数载流子寿命的测定表明,异质结势垒电场能有效地增强光生电子-空穴对的分离效率.根据能带理论建立的两组异质结能带模型可合理地解释实验结果. 相似文献
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