双峰倍增配平法用于同步、导数-同步荧光法同时测定邻羟基苯甲酸和间羟基苯甲酸

邻羟基苯甲酸（ｏＨＢＡ）和间羟基苯甲酸（ｍＨＢＡ）荧光光谱严重重叠，同步及导数技术虽使选择性有所改善，但仍不能完全分辨开重叠谱。用双峰倍增配平计算法结合同步、一阶导数－同步荧光法对双组分体系（邻羟基苯甲酸／间羟基苯甲酸，ｐＨ１２介质）同时测定。结合计算的两种测定方法精密度、回收率和不同组分间浓度比范围均优于一阶导数－同步荧光法。     

Gas chromatographic conditions for the linearity of the relationship between σT,t and tR in open tubes

The linearity of the relationship between σ_T,t² and (1 + k)² is studied with the view of using it for the evaluation of GC equipment. Based on appropriate analytical expressions it is concluded that in general this relationship is not linear and that practical procedures for column evaluation should be developed that take this non-linearity into account.     

Brownian motion of nonlinear oscillators: The projection operator method and its application to a double-well-potential oscillator

A projection operator method is presented, which provides the most efficient way for calculating the stationary behavior of nonlinear Brownian motion. A continued-fraction expansion of the Fourier-Laplace transform of the displacement correlation function or the spectral density is used. This method utilizes a successive optimization procedure on the nonlinear terms and includes the method of statistical linearization as the lowest order approximation. A systematic way to calculate the continued fraction numerically up to sufficient order for convergence is developed, which enables us to obtain the spectral density of a system previously uncomputable.Numerical computations of the spectral density of a nonlinear oscillator with a double-well potential are presented and compared with the results obtained by statistical linearization.This work was supported in part by the National Science Foundation under Grant CHE 75-20624.     

弛豫理论对离子交换毛细管电色谱中峰压缩现象的研究

 在毛细管电色谱中,由于溶质在输运过程中所具有的电性质,常会产生一些特殊的现象。这些现象,如离子交换毛细管电色谱中产生超高柱效峰的现象,已经不能用一般的色谱理论加以解释。基于弛豫理论所建立的基本模型,在考虑溶质在两相中皆有可能发生正、反向迁移的情况下,得到了流出曲线一阶原点矩和二阶中心矩的理论表达式,并通过对溶质在两相中电扩散速率与电泳速率、电渗流速率关系的分析结果证实:溶质在固定相表面的电扩散行为可以使其保留变弱,出峰加快;而这种电扩散导致的超常柱效峰的出现具有不稳定性,只有在多方面因素综合影响匹配的情况下才可能出现。     

塔板理论对柱内和柱外浓度分布曲线的描述

使用Visual Basic和QBasic程序，分别在Excel和DOS上，在不做任何化简的情况下，对塔板理论描述的柱内和柱外组分浓度分布进行了研究。发现符合线性分配的样品组分在色谱柱内存在3种不同的浓度分布形态，在色谱柱外则都是拖尾峰形态。分析了不同分配比对柱内和柱外浓度分布曲线最高点和次高点的影响。     

紫外吸收温差光谱法及其应用

用温差光谱法观察系列化合物的紫外吸收温差谱，发现温差谱具有很强的特征性，具有π键的富勒烯Ｃ６０的温差谱峰为负值，负峰的强度样品温差增大而负荷增大，负峰的峰位无明显移。     

Hepatobiliary excretion and brain distribution of caffeine in rats using microdialysis

To investigate the pharmacokinetic mechanism of hepatobiliary excretion and brain distribution of caffeine, this study uses a method based on microdialysis technique and liquid chromatography that allows continuous and concurrent in vivo monitoring of extracellular caffeine in the blood, brain and bile of anesthetized rats following the administration of caffeine (3 or 10 mg/kg, i.v.) through the femoral vein. Dialysates of the blood, brain and bile were directly injected onto the liquid chromatographic system and no further clean-up procedures were required. The study design consisted of two groups of six rats in parallel: the rats of the control group received caffeine (3 or 10 mg/kg, i.v.) alone and those of the cyclosporine treated-group were injected cyclosporine (10 mg/kg, i.v.) 10 min prior to caffeine administration (3 or 10 mg/kg, i.v.). The decline of caffeine in the blood, brain striatum and bile suggested that caffeine had rapid exchange and equilibration between the peripheral compartment and the central nervous system. In addition, the results indicated that caffeine underwent hepatobiliary excretion and was distributed into brain. When cyclosporine was co-administered, the pharmacokinetic parameters were not significantly altered. The results of this study reveal that the pharmacokinetic mechanism of hepatobiliary excretion and brain distribution of caffeine might not relate to P-glycoprotein.     

凝胶渗透色谱法测定聚丙烯腈共聚物分子量中宽分布校正法的应用

应用宽分布校正法对凝胶渗透色谱(GPC)进行了校正，将校正曲线用于聚丙烯腈(PAN)共聚物分子量的计算。对扣除色谱峰扩展效应前后的测试结果与乌氏粘度法测得的数据进行比较。结果表明，应用宽分布校正法时，必须扣除色谱峰扩展效应，才能得到较为准确的测试结果。     

Infrared spectroscopic study of the interactions of nylon‐6 with water

We studied the interactions of nylon‐6 with water by following the Fourier transform infrared spectra of a hydrated thin film during dehydration. Very small changes in the spectra caused by the interactions were clearly revealed by the application of spectral subtraction. The water was found to interact with amide groups to form hydrogen bonds with non‐hydrogen‐bonded or free C?O and NH groups in the amorphous portion in the first hydration sphere. This was deduced from an analysis of minus and plus peaks appearing around the absorptions of the NH stretching, amide I band, and amide II bands in the difference spectra between the spectra during dehydration and the one at the most dehydration. The interactions of the amide groups with water were significantly stronger than the hydrogen bond between CO and NH in the crystalline portion, according to the magnitude of the frequency shift of relevant bands. Water, as the interacting counterpart, showed a distorted OH stretching absorption with two close peaks at about 3450 cm^?1. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1722–1729, 2003