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31.
A computer simulation is reported of the enantiomer S CHBrClF subjected in the liquid state to intense external fields of force : i) uniaxial electric field EZ; ii) circularly polarised field at optical frequencies. The molecular dynamics are quantified in detail at field - on equilibrium in case i) using a range of auto correlation functions. The foremost result of the investigation is that the simple uniaxial field EZ makes the sample in a well defined direction. The direct effect of EZ on an isolated molecule of S-CHBrClF is purely rotational, but intramolecular rotation/translation coupling converts this rotation into coherent centre of mass translation. This gives rise to direct, , cross correlations of the type <v(t)T(o)> where is the molecular centre of mass translational velocity and T the transposed molecular angular momentum vector. (The existence of these invalidates the classical theory of the Kerr effect.) The molecular dynamics of the hypothetical chiral ion S-CHBrClF? are looked at with a view to corroborating the predictions by Baranova et al. concerning their response to electric field treatment. Despite the inherent instability of such an ensemble of like-charged ions the simulation can be used to produce a range of auto and cross-correlation functions with which to characterise the ionic dynamics. The effect of treating the ionic ensemble with a field EZ is reported briefly in terms of the non-vanishing ensemble averaged centre of mass velocity <vZ&>;.The induced translation in an electric field may be demonstrated on most liquids using a simple experimental set up. Its importance in optically active systems is such that it may be used to separate a racemic mixture into its enantiomers, the translational motion induced in the one enantiomer is necessarily, by symmetry, opposite to that induced in the other enantiomer. The observation therefore has technological importance. Other applications are discussed. 相似文献
32.
33.
Tomasz J. Michalski Ady Kendler Myron L. Bender 《Journal of inclusion phenomena and macrocyclic chemistry》1983,1(2):125-128
The title compound (II) was prepared by treating dry, purified α-cyclodextrin with 20 equivalents oft-butyldimethylsilyl chloride 20 hr at 110° in DMF/pyridine. Work-up of the product mixture gave 60%II, which was identified by1H and13C NMR. Treatment ofII with Bu4NF 6 hr in refluxing dry THF efficiently removed the protecting groups. 相似文献
34.
Myron?Mathisson 《General Relativity and Gravitation》2010,42(4):989-1010
This is an English translation of the first of two papers by Myron Mathisson, first published in German in 1931 and 1937, in which he presented the correct formulation of equations of motion of spinning bodies in general relativity (today known as the Mathisson–Papapetrou equations). The papers have been selected by the Editors of General Relativity and Gravitation for republication in the Golden Oldies series of the journal. This republication is accompanied by an editorial note and Mathisson’s brief biography, both written by Andrzej Trautman. 相似文献
35.
Izo I. Abram Robin M. Hochstrasser James E. Kohl Myron G. Semack David White 《Chemical physics letters》1980,71(3):405-408
Hydrogen crystals were pumped by stimulated Raman gain into coherent superpositions of the ground and 2 v = 1 vibrational exciton state and its amplitude monitored by coherent anti-Stokes scattering. The resulting non-exponential and temperature independent (1.6–4.2 K) decays, for o-H2 concentrations between 0.22 and 2.7%, were attributed to compositional scattering. 相似文献
36.
We present a scheme for solving two‐dimensional, nonlinear reaction‐diffusion equations, using a mixed finite‐element method. To linearize the mixed‐method equations, we use a two grid scheme that relegates all the Newton‐like iterations to a grid ΔH much coarser than the original one Δh, with no loss in order of accuracy so long as the mesh sizes obey . The use of a multigrid‐based solver for the indefinite linear systems that arise at each coarse‐grid iteration, as well as for the similar system that arises on the fine grid, allows for even greater efficiency. © 1999 John Wiley & Sons, Inc. Numer Methods Partial Differential Eq 15: 317–332, 1999 相似文献
37.
Myron Pankevich Ju. Linhart 《人工晶体学报》2006,35(5):963-975
本文通过分析光学材料中光谱与温度之间的关系证实了晶体生长过程中的相变团簇模型,认为晶体内部热辐射流是引起固-液界边界层温度场发生传导的可能原因.引入了前结晶的概念,并结合实际中的不同晶体生长方法讨论了包裹体及气泡的抑止机理,通过计算得到了生长理想晶体的最大生长速率并且解释了由于界面层的摆动使得晶体生长过程中产生的微气泡没有被移动的界面层所捕获. 相似文献
38.
Myron Mathisson 《Mathematische Annalen》1933,107(1):400-419
Ohne Zusammenfassung 相似文献
39.
Bruce M. Foxman Philip T. Klemarczyk Robert E. Liptrot Myron Rosenblum 《Journal of organometallic chemistry》1980,187(2):253-265
A number of complexes CpFe(CO)2(L) (L = aldehyde, ketone, ester, amide) have been prepared either by treatment of [CpFe(CO)2]2 or CpFe(Co)2Br with AgPF6 in the presence of L or by a ligand exchange reaction employing CpFe(CO)2(isobutylene)BF4. NMR spectral data suggest that these complexes involve iron—oxygen σ-bonding rather than π-bonding to the carbonyl group. This is confirmed by an X-ray structure determination of the 3-methylcyclohexenone complex. The exchange stability of these complexes parallels their basicity. 相似文献
40.
Computer simulation is revolutionizing the field of liquid state dynamics and revealing the limited scope of the traditional approach of study by combined molecular spectroscopy and analytical modelling. The experiments produce composite profiles that are not easily deconvoluted in terms of the contributory relaxation processes while the theories are based on simplistic and subjective ideas. Little real progress has resulted from the immense effort expended in an attempt to elucidate the liquid state. Computer technology, however, is changing all this because the N-body problem is now being solved and new predictions are being made. For the first time we can explain why, in dynamical terms, a racemic mixture of lactic acid is a liquid at room temperature yet a single enantiomer of the same a solid. It emerges that molecular shape is critical in determining the dynamics of the condensed phase of matter. 相似文献