利用傅里叶红外显微化学图像系统鉴定书写与盖章的先后顺序

采用傅里叶变换红外显微化学图像系统并结合面扫描和反射模式对书写与盖章的先后顺序进行了无损、快速鉴定,结果表明先盖章后写字的红外谱图中墨水的特征峰吸收明显,先写字后盖章的红外谱图中印油的特征峰吸收明显。该法具有快速、准确、客观和不损坏样品等特点。     

马来酸氢十八酯晶体(OHM)的拉曼光谱研究

为了进一步了解马来酸氢十八酯晶体（ＯＨＭ）的结构,本文测定了ＯＨＭ晶体几何配置为（ｙ（ｚｘ）ｙ）和ｙ（ｘｚ）ｙ和ｙ（ｘｘ）的拉曼光谱。实验表明ＯＨＭ烷烃链的几个振动模式出现偏振,垛;ＯＨＭＳ其他基团的拉曼光谱振动吸收峰也都具应出现。     

高效液相色谱-二极管阵列检测器法测定咖啡、茶叶中咖啡碱、茶碱和可可碱

将高效液相色谱,晶体二极管阵列检测器联用与正交投影分析结合,建立了一种从天然复杂样品中直接定性定量的分析方法。讨论了二维色谱重叠峰中背景的检测与扣除,纯色谱曲线的分辨和组分的定性定量分析。将这一方法用于咖啡和茶叶中咖啡碱,茶碱与可可碱的测定取得满意效果。     

Quadrupole relaxation enhancement and polarisation transfer in DMSO solution of [Bi(NO3)3(H2O)3]*18-crown-6 in solid state

ABSTRACT

¹H spin-lattice relaxation studies have been performed for pure [Bi(NO₃)₃(H₂O)₃]*18-crown-6 in powder and its solution in dimethyl sulfoxide (DMSO). The experiments have been carried out in the frequency range of 10?kHz–30?MHz and the temperature range of 240–277?K; at 277?K the solution is already frozen. The ¹H relaxation of pure [Bi(NO₃)₃(H₂O)₃]*18-crown-6 has been interpreted in terms of three dynamical processes. Quadrupole Relaxation Enhancement effects have been observed in the frozen DMSO solution of [Bi(NO₃)₃(H₂O)₃]*18-crown-6. The specific mechanisms of the ¹H spin-lattice relaxation enhancement have been discussed distinguishing between effects caused by time independent (residual) and fluctuating ¹H-²⁰⁹Bi dipole-dipole interactions.     

THz光谱技术在炸药及其相关材料检测中的应用进展

太赫兹（THz）光谱技术近年来在航空航天、生命科学、安全检测等领域的应用进展迅速.由于许多炸药及其相关材料在THz波段具有特征吸收，许多非金属、非极性材料对THz波是透明的。且THz波具有低能性，THz光谱技术在安检中具有巨大的应用潜力．文章介绍了国际上THz光谱技术在炸药及其相关材料研究中的现状和进展及文章作者在炸药及其相关材料THz光谱研究方面的成果，讨论了THz技术应用于安全检测领域面临的挑战.     

Absorptive reduction and width narrowing in Λ-type atoms confined between two dielectric walls

This paper investigates the absorptive reduction and the width narrowing of electromagnetically induced transparency （EIT） in a thin vapour film of A-type atoms confined between two dielectric walls whose thickness is comparable with the wavelength of the probe field. The absorptive lines of the weak probe field exhibit strong reductions and very narrow EIT dips, which mainly results from the velocity slow-down effects and transient behaviour of atoms in a confined system. It is also shown that the lines are modified by the strength of the coupling field and the ratio of L/λ, with L the film thickness and λthe wavelength of the probe field. A simple robust recipe for EIT in a thin medium is achievable in experiment.     

System peaks observed in capillary liquid chromatography with eluents containing triethylamine

Summary Triethylamine is often added to mobile phases in reversed-phase liquid chromatography for dynamic deactivation of free silanol groups of the stationary phase. It has been observed that eluents composed of methanol and triethylamine generate two system peaks in chromatograms obtained with LiChrosorb RP-select B stationary phase, whose retention times correspond to the dead time and to the retention time of triethylamine. It has been demonstrated that the system peaks can be positive or negative depending on the experimental conditions and may be incorrectly interpreted as peaks corresponding to sample components. An approach is outlined to unambiguous identify these system peaks in chromatograms of practical samples.     

Explicit model realizing parton-hadron duality

An explicit model realizing parton-hadron duality and fitting the data is suggested. Complex nonlinear Regge trajectories are important ingredients of the model. The inclusion of Δ and N^* trajectories should account for all resonances in the direct channel. The exotic trajectory is responsible for the smooth background. Received: 7 June 2002 / Accepted: 3 July 2002 / Published online: 10 December 2002 RID="a" ID="a"e-mail: fiore@cs.infn.it RID="b" ID="b"e-mail: flachi@ifae.es RID="c" ID="c"e-mail: jenk@gluk.org RID="d" ID="d"e-mail: sasha@len.uzhgorod.ua RID="e" ID="e"e-mail: vladimir@cfif.ist.utl.pt Communicated by V.V. Anisovich