Gas-liquid chromatography of perfluorocarboxylic thioesters

Perfluorocarboxylic thioesters R_FC(O)SR (R_F=CF₃(CF₂)_j, R=CH₃(CH₂)_i, i andj=0–5) were studied for the first time by GLC on packed columns using SE-30, SKTFT-50X, and XE-60 as the stationary phase. The values of thermodynamics functions of sorption were calculated. The correlations between these functions and the molecular structures as well as the conditions of analysis were established. The insertion of the S atom into the molecules of derivatives of perfluorocarboxylic acids causes a decrease in the contribution of the orientation interaction and an increase in the dispersion interaction of thioesters with the stationary phases compared to esters and amides of perfluorocarboxylic acids studied previously. For Part 1, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1165–1168, June, 1997.     

Lithographic design of photosensitive polyarylates based on reaction development patterning

The factors affecting pattern‐forming properties in reaction development patterning were examined with polyarylates with various bisphenol moieties. The developability of the photosensitive polyarylates was dependent on the properties of the subtituent (R) in the bisphenol moieties. The development time decreased in the following order: R?C(CH₃)₂ > fluorenyl unit ? phenolphthalein unit > C(CF₃)₂ > SO₂. This order agreed with that of the reactivity between the polyarylates and ethanolamine, and these orders can be explained by pK_a of the bisphenol used to prepare the polyarylates. The development with NH₂? R′? OH resulted in successful positive‐tone pattern formation. However, pattern formation with the developers containing NH₂? R′? OCH₃ was unsuccessful. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2694–2706, 2006     

Dispersion relations and the spin polarizabilities of the nucleon

A forward dispersion calculation is implemented for the spin polarizabilities γ₁,,γ₄ of the proton and the neutron. These polarizabilities are related to the spin structure of the nucleon at low energies and are structure-constants of the Compton scattering amplitude at . In the absence of a direct experimental measurement of these quantities, a dispersion calculation serves the purpose of constraining the model building, and of comparing with recent calculations in heavy baryon chiral perturbation theory.     

Convergence of dynamical zeta functions

I study poles and zeros of zeta functions in one-dimensional maps. Numerical and analytical arguments are given to show that the first pole of one such zeta function is given by the first zero ofanother zeta function: this describes convergence of the calculations of the first zero, which is generally the physically interesting quantity. Some remarks on how these results should generalize to zeta functions of dynamical systems with pruned symbolic dynamics and in higher dimensions follow.     

A complementary thermodynamic limit for classical Coulomb matter

The canonical equilibrium measure of classical two-component Coulomb matter with regularized interactions is analyzed in a finite volume. It is shown that, in the mean-field regime, the one-particle density is inhomogeneous on a new characteristic length scale _inh. For a system ofN positive andN negative particles, _inh and the characteristic length scale of correlations _corr (=Debye screening length) are related via _inh=(2N)^1/2 _corr. The major conceptual conclusion that is drawn from this is that one needs two nontrivial complementary thermodynamic limits to define the equilibrium thermodynamics of two-component Coulomb systems. One of them is the standard thermodynamic limit (infinite volume), where one takesN, _corr fixed. Its complementary limit is characterized byN, _inh fixed, and is a finite-volume inhomogeneous mean-field limit. The most prominent new feature in the mean-field thermodynamic limit, which is absent in the standard thermodynamic limit, is an anomalous first-order phase transition where the Coulomb system explodes or implodes, respectively. The phase transition is connected with the existence of a metastable plasma phase far below the ionization temperature.     

氮杂冠醚与碱金属离子配位反应的研究

滴定量效法是研究反应热化学和热力学的重要手段之一．用这种方法对冠醚与金属离子的配位反应热力学性质进行研究一直受到很大关注【且S习．但是对氨杂冠林，尤其是一系列结构相似的氨杂冠醚体系进行系统的热力学性质研究的报导不多．前文K则曾报导了用自组装的消定量热计对银（I）－a吹体系和铜（11）·N，N’一问位取代革基乙二胺体系的配位反应热化学研究结果·本文报导从（对位取代革基）k杂15冠5卜RPW15CS，R＝CIZH；CHa；CHso）与碘化钠和碘化钾在25T、无水乙过溶液中进行配位反应的消定量效研究结果．讨论了配体上取代基的电…     

TCDD的密度泛函理论研究

用B3LYP/6-311G~(**)方法全优经计算22个四氯二苯并对二（左口右恶）英（ 简称TCDD）分子，得到几何构型、总能量、标准熵、标准焓和标准自由能。将2， 3，7，8－TCDD的计算构型与X射线衍射实验测定值进行了比较。计算结果表明，总 能量、标准焓和标准自由能与氯原子量换位置的相关性很高（r > 0.997）.1,3,6, 8-TCDD的总能量处自由能最低，即最稳定，以此参照，得到异构体的总能量的相对 稳定性顺序和自由能的相对稳定性顺序。1,3,7,9－TCDD的稳定性次之，1,3,7,8- TCDD居第三，将这二个顺序与焚烧炉产生的TCDD异构体和合成的异构体对的生成面 分比进行了比较，说明焚烧炉中产生的TCDD和合成的TCDD对的分布主要受热力学控 制。     

Temperature Development of Homo- and Hetero-Clustering in Saturated Vapors

Computational findings of temperature increase of clustering degree in saturated vapors are analyzed. A thermodynamic proof is presented and a simple criterion derived. Illustrations are based on saturated steam, magnesium and carbon vapor. The results are applicable to synthesis of fullerenes, metallofullerenes, and heterofullerenes, chemical vapor deposition technique, or atmospheric chemistry.