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221.
222.
《Journal of separation science》2005,28(13):1467-1475
The identification of various petroleum products, which can be used to set a fire, is one of the tasks of a forensic examination. One of the analytical problems is differentiation of weathered kerosene and diesel fuel samples, analysed with automatic thermal desorption‐GC‐MS technique, because there are only small quantitative differences in their chemical compositions. The presented research showed that the observed differences in the analysed samples of kerosene and a diesel fuel, which were weathered at the time of burning, were systematic and significant. Therefore, it was possible to distinguish them on the basis of information about the relative content of n‐alkanes (C11H24–C15H32) when statistical methods (cluster analysis and likelihood ratio approach) were applied. 相似文献
223.
甲基丙烯酸丁酯和苯乙烯的原子转移自由基共聚 总被引:2,自引:0,他引:2
研究了甲基丙烯酸丁酯和苯乙烯两种不同极性单体的原子转移自由基嵌段共聚和无规共聚,得到了实测分子量与理论分子量相近、分子量分布较窄的嵌段共聚物和无规共聚物。聚合过程中分子量和单体转化率成比例增加,多分散性指数变化不大。用^1H NMR法测定共聚组成,Kdisplay status 相似文献
224.
Martin Schwarz Jr. 《Journal of statistical physics》1976,15(3):255-261
In the present study we investigate the statistical thermodynamics of the anharmonic oscillator, whose energies are characterized by the potential 1/2x
2+x
4. Employing the energies recently obtained by Hioe and Montroll, we compute the partition function and the thermodynamic quantities for the anharmonic and quartic oscillators. Low- and high-temperature formulas are presented for the thermodynamic quantities of the oscillators. 相似文献
225.
H. Kleinen 《Journal of statistical physics》1989,56(1-2):227-232
The effect of the tangential flow, in fluid membranes, on the renormalization of the curvature elastic constant is studied and it is shown that the softening of when averaged over increasingly short distance scales is the same as for ideal surfaces carrying no material. This is in contrast with a recent claim by Förster. The physical and formal differences in the two treatments are pinpointed. 相似文献
226.
The
n
Baxter model is an exactly solvable lattice model in the special case of the Belavin parametrization. For this parametrization we calculate the partition function,, in an antiferromagnetic region and the order parameter in a ferromagnetic region. We find that the order parameter is expressible in terms of a modular function of leveln which forn = 2 is the Onsager-Yang-Baxter result. In addition we determine the symmetry group of the finite lattice partition function for the general
n
Baxter model. 相似文献
227.
228.
基于氢键的形成和缩聚反应机理在统计意义下的相似性,利用高分子反应统计理论和反应动力学理论对氢键溶液的一个模型体系进行了相关讨论.给出了体系的溶胶分数和发生溶胶-凝胶相变的条件,指出质子受体基团间的竞争作用对溶胶凝胶相变点的影响,进而讨论了体系的数量分布函数和相关问题. 相似文献
229.
A simple model for the phase behaviour of a globular protein and a flexible polymer in an aqueous medium is described, in which both the compact feature of the protein and the flexble feature of the polymer have been included. The phase diagrams calculated by using the model suggest that for a given protein, the behaviour depends strongly on the polymer molecular weight. Fluid-fluid-solid three-phase and fluid-fluid two-phase equilibria can be found only when the polymer molecular weight is sufficiently high; otherwise, the only two-phase region in the phase diagram is a fluid-solid two-phase region. 相似文献
230.
Monte Carlo simulations have been carried out for 2-ethoxyethanol (C2E1) in isothermal-isobaric ensemble (NPT) at different temperatures and 1 atm pressure with a continuum configurational biased
procedure in water and chloroform media. Hydrogen bond bridges were formed between adjacent oxygen atoms in C2E1 (CH3CH2OCH2CH2OH) through water molecules. We also found that the stable conformers of C2E1 in water and CHCl3 are different and the effect of temperature on solute-solvent interaction energies is considerable. The self-association
of C2E1 in aqueous and nonaqueous media has been studied by statistical perturbation theory, and the relative free energy has been
obtained at different reaction coordinates by double-wide sampling method. Two minima were found in water solvent in the potential
of mean force (PMF), corresponding to the contact and solvent-separated pairs, but only one minimum was found in CHCl3 solvent corresponding to a contact pair complex.
Received: 18 January 2001 / Accepted: 22 October 2001 / Published online: 21 January 2002 相似文献