“首项分裂”的进一步验证及所发现的异常峰形

采用ＨＰ－５８９０Ａ气相色谱仪,ＨＰ－３３９２Ａ积分仪（工作在ＰＬＯＴ方式）,配用长３０ｃｍ、内径０．５ｍｍ涂ＤＮＰ的铜毛细管柱,柱温１００℃,０．１μＬ正十四烷为样品,采用单池热导及氢焰检测器,通过改变流速再次验证了“首项分裂”现象。完成实验的关键是设法克服伴随进样过程产生的干扰。实验过程中再次发现了异常峰形。     

用四种离散变换主组分回归方法分辨重叠吸收光谱

将离散小波变换、小波包变换、傅里叶变换和离散余弦变换与主组分回归方法结合构成4种离散变换主组分回归方法,编制了离散变换主组分回归方法的计算程序。将离散变换主组分回归方法用于处理对硝基甲苯、对硝基酚和对硝基苯胺混合物的重叠紫外吸收光谱数据。结果表明,离散变换主组分回归方法优于主组分回归方法,试样质量浓度的预测值与实际值的相对预测标准误差由3.81%降至约1.11%。     

双光谱二维异步相关光谱表征分子间相互作用的可行性研究

双光谱二维异步相关光谱(2T2D-异步相关光谱)是一种利用两幅一维光谱创建异步相关光谱的新方法。相对于最少需要三幅一维光谱的传统异步相关光谱, 2T2D-异步相关光谱可简化实验过程,有利于样品昂贵体系的表征。利用数学分析、模拟及实际体系实验对2T2D-异步相关光谱应用于表征分子间相互作用的可行性进行了研究。首先建立一个包含P和Q两种溶质的模拟体系,设定P有光谱峰, Q没有光谱峰。数学分析表明:(1)不正确设置P和Q初始浓度,可导致2T2D-异步相关光谱的强度恒为零;(2) 2T2D-异步相关光谱不能反映与分子间相互作用相关的峰强变化;因此,利用2T2D-异步相关光谱表征分子间相互作用可能得到错误的结论。为将2T2D-异步相关光谱发展成为表征分子间相互作用的可靠方法,首先对2T2D-异步相关光谱中P和Q初始浓度的设置方法进行了研究,得出当P和Q初始浓度满足文中式(6)时,可避免不正确设置P和Q初始浓度导致2T2D-异步相关光谱强度恒为零的情况;在此基础上,为解决2T2D-异步相关光谱不能反映与分子间相互作用相关的峰强变化问题,通过向体系中加入具有独立光谱峰和适合浓度的虚拟物质S,发展出带有辅助交叉峰的2T2D-异步相关光谱(ASAP-2T2D-异步相关光谱)。模拟体系实验表明ASAP-2T2D-异步相关光谱可正确反映与分子间相互作用相关的峰宽、峰位及峰强变化,是表征分子间相互作用的可靠方法。最后,将ASAP-2T2D-异步相关光谱应用于表征苯并-15-冠醚-5(BC)与Li^+间的相互作用,实验结果表明ASAP-2T2D-异步相关光谱可同时反映BC特征峰的峰位及峰强变化,进一步证实ASAP-2T2D-异步相关光谱可正确表征分子间相互作用。     

Deuteron photodisintegration within the Quark-Gluon Strings Model and QCD motivated nonlinear Regge trajectories

We investigate deuteron two-body photodisintegration within the framework of the Quark-Gluon Strings Model with nonlinear baryon Regge trajectories. Special attention is paid to the use of QCD motivated Regge trajectories of the logarithmic and square-root form. We find that the recent experimental data from TJNAF in the few-GeV region can be reasonably described by the model. Angular distributions at different γ-energies are presented and the effect of a forward-backward asymmetry is discussed. Predictions for the energy dependence of dσ/dt at higher energies and different Θ_c.m. are presented, too. Received: 12 March 2001 / Accepted: 19 March 2001     

Note on the impact parameter analysis of high-energy proton-proton collisions

Following a prior analysis of measured pp elastic differential cross-sections, the impact parameter representation in terms of profile functions is calculated from two different parametrizations of single diffractive dissociation data. The derivative of this quantity, with respect to the collision energy squared s, measures the growth rate of the reaction's blackness. Its distribution in impact parameter space allows detailed insight into the growth pattern of the total diffractive cross-section and the approaching unitarity limit. Comparing the results with the elastic case, the different mechanisms of unitarization of two parametrizations are discussed. Received: 19 January 2001 / Accepted: 11 July 2001     

二极管阵列检测高效液相色谱重叠峰的双波长分析方法

把光度分析的双波长法应用于二极管阵列检测高效液相色谱重叠峰的数据处理。对于色谱峰严重重叠的双组分,只要它们的紫外可见吸收光谱有差异,就可通过计算两个波长下的峰面积（其中一个组分在这两波长时的峰面积之比为常数ｋ,并通过计算另一个组分在ｋ比例系数下的两波长峰面积差）进行定量测定。检测了混合硝基苯类化合物,结果令人满意。     

正交投影用于多波长色谱重叠峰分析

 将正交投影分辨 (OPR)技术用于多波长色谱重叠峰分辨 ,当色谱峰中最大重叠度小于或等于波长数时 ,用这一方法能从多波长色谱重叠峰中获得完全真解。基于双波长色谱分析 ,提出了一种新的色谱重叠峰中背景校正、组分数和纯组分信号区确定以及各组分重叠情况的分析方法 ,即双波长特征信息分析 (DWCI)。该法被成功的用于三组分双峰和双组分单峰重叠色谱的分析。     

Study on Separation Method of Overlapped Peaks in Differential Thermal Analysis with Computer Simulation

With the computer simulations, it has been found that in Differential Thermal Analysis (DTA) the overlapped peaks do not satisfy the linear overlapping principle, and the relationship between the overlapped peaks is rather complex that is a function of sample thermal conductivity, specific heat, quantity and latent heats, etc. If the first point where the two peaks begin to overlap is at the posterior half of the first peak curve and the two overlapped peaks can be identified by two different peaks, from the curve of overlapped peaks we can know that the temperature corresponding to the first point deviating from the sample's first phase change curve is the sample's second phase change temperature. This revised version was published online in August 2006 with corrections to the Cover Date.     

正交投影用于一维重叠色谱峰分辨及背景扣除

对于两组份色谱重叠峰体系,当以小组份色谱峰作为干扰时,本文利用正交投影方法,通过构造正交投影矩阵,利用原始信号及其投影与背景之间的内在关系来确定真实背景,从而将背景干扰予以扣除,使含背景干扰的一维重叠色谱峰得以分辨。模拟研究表明,对于两组份色谱峰重叠体系当以小色谱峰为干扰时本文方法具有很好的分辨效果,对于完全重叠峰,即使其峰分离度为零能得到满意的结果。     

Different Behavior of Organotin Compounds by Anodic Stripping Voltammetry and their Quantification after Partial Ion Exchange Separation

 The electrochemical behavior and the analytical performance of the organotin compounds mono-, di- and tributyltin, as well as, mono-, di- and triphenyltin were investigated by various voltammetric techniques, such as alternating current polarography of the first harmonic (ACP1), square wave polarography at a hanging mercury drop electrode (SQW) and anodic stripping voltammetry (ASV). Differences could be observed in the sensitivity, the detection limit and the reproducibility of the organotins by the techniques used and in some cases their simultaneously determination was difficult, as the half-wave potentials were very close together. However, by ASV double peaks were observed only for the monophenyltin and dibutyltin species, distinguishing them from the overlapping peaks of diphenyltin and triphenyltin, respectively. This different electrochemical behavior, is due to the formation of intermediate products during the electrolysis of these compounds with other half wave potentials and was successfully utilized for the separation and determination of monophenyltin in the presence of diphenyltin. In the case of dibutyltin, where no linear calibration curves for the two peaks were obtained, a prior suitable ion exchange procedure was developed for its separation and determination from the interfering triphenyltin. The successful application of this technique could be proved on a CRM freshwater sediment of BCR.