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991.
992.
We generalize the Bogoliubov functional hypothesis to the case of multiparticle interaction depending on both the coordinates and momenta of particles. We illustrate this with the examples of two weakly relativistic models: the Darwin model in the theory of charged particles and the Fock model in the general theory of relativity. For these models, based on the chain of the BBGKY equations, we calculate weakly relativistic corrections to the classical transport coefficients and find the conditions under which there is no bijective relation between the parameters of the local equilibrium distribution and the hydrodynamic variables. 相似文献
993.
介绍国内外连续流动式聚合酶链式反应生物芯片/微装置中脱氧核糖核酸样品的驱碧控制技术进展,主要包括恒流泵(注射泵驱动和蠕动泵驱动)、旋转泵驱动、磁流体动力驱动以及自然对流驱动等。并对这几种驱动方式的优缺点作简要的讨论(引用文献43篇)。 相似文献
994.
Decheng Wan Qiang Fu Junlian Huang 《Journal of polymer science. Part A, Polymer chemistry》2005,43(22):5652-5660
A novel thermoresponsive shell crosslinked three‐layer onion‐like polymer particles were prepared using hyperbranched polyglycerol (PG) as parents compound, the periphery hydroxyl groups of PG were transformed into trithiocarbonates (? SC(S)S? ) first; then, it was used as chain transfer agent to prepare star‐like block copolymer of N‐isopropyl acrylamide (NIPA) and N,N‐dimethylaminoethyl acrylate (DMA) in sequence via reversible addition fragmentation chain transfer (RAFT) process. Thus, a three‐layer polymer, PG? [SC(S)S? (DMA)? b? (NIPA)]n, was obtained. The middle layer of poly(DMA) was then crosslinked with 1,8‐diiodoctane, and the resulting onion‐like three‐layer polymer showed a lower critical solution temperature (LCST) in water because of the outer layer of poly(NIPA). The LCST value only slightly depended on the crosslinking degree. Finally, the ? SC(S)S? were transformed into thiols by sequential treating with sodium borohydride and formic acid; thus, the core molecule was chemically detached from the crosslinked shell and a novel shell crosslinked polymer particle was obtained. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5652–5660, 2005 相似文献
995.
Zhiming Li 《Journal of Mathematical Analysis and Applications》2003,286(2):724-740
In this paper we first establish a new general criterion for the permanence of Kolmogorov-type systems of nonautonomous functional differential equations. Then, as applications of this criterion we study the permanence of a class of n-species general nonautonomous food chain systems with delay and new sufficient condition are established. 相似文献
996.
The paper deals with periodical task scheduling. The tasks are described by fuzzy due dates and fuzzy execution times. The goal of scheduling is to find an optimal assignment of priorities such that the satisfaction associated with due dates and execution times be minimized. The paper shows how the rules associated with task priorities improve the optimal assignment search. 相似文献
997.
W. G. Hiller H. Schneider V. D. Fedotov 《Journal of Polymer Science.Polymer Physics》1992,30(9):931-942
A theoretical treatment of the nonexponential relaxation behavior of the different proton nuclear magnetic resonance (NMR) relaxation processes in polymer melts is presented. Formulas are derived for a three-component model given by two versions and a homogeneous distribution of correlation times. The theoretical results were tested with measurements of T1, T2e, and T2 as functions of frequency and molecular mass in linear fractionated polyethylene samples. While the T1 relaxation always yields exponential magnetization decays, the T2e and T2 measurements show biexponential relaxation behavior. From the calculations it was found that the correlation time of the local motion is independent of the molecular mass, whereas the correlation time of the slowest motional process increases with M2.8w for the three-component model and with M2.2w for the distribution of correlation times, respectively. © 1992 John Wiley & Sons, Inc. 相似文献
998.
Jun Lu Rui Huang Yong Chen Liangbin Li 《Journal of Polymer Science.Polymer Physics》2006,44(21):3148-3156
Morphologies of extended‐chain crystals with different characteristics were observed with scanning electron microscopy (SEM) in the high‐pressure crystallized polyethylene terephthalate/polycarbonate (PET/PC) blends. The crystals memorize their nucleation and growth process, which reveal an involvement of different mechanisms simultaneously. The presence of sliding diffusion during crystal thickening is indicated by a wedge shape of some crystals, while bent crystals suggest the occurrence of transesterification in the formation of the large extended‐chain crystals. The observation of two morphological features on one group of crystals shows that two mechanisms may work simultaneously. The connection between folded‐chain and extended‐chain crystals is demonstrated by the S‐shaped extended‐chain crystals as well as their direct morphological connection observed with SEM. Though transesterification plays the essential role in the formation of the large crystals, which acts in different aspects during the process, the thermodynamic driving force is the enthalpy gain associated with large crystals. This is a high‐pressure self‐assembly with a coupling between crystallization and transesterification, which may be instructive to grow such large crystals in similar polymer systems. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3148–3156, 2006 相似文献
999.
We consider a multiple-integral representation for a one-parameter generating function of the finite temperature Sz-Sz correlation functions of the antiferromagnetic spin-1/2 XXZ chain in the XX limit and in the Ising limit. We show how the
multiple integrals reduce to single integrals in these limits, thus reproducing known results.
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 146, No. 1, pp. 146–160, January, 2006. 相似文献
1000.
具有通用机的n组工件的排序问题 总被引:4,自引:0,他引:4
本文讨论了具有n台速度相同的专用机,一台同速度的通用机的n组工件的Cmax问题,提出了改进的LPT算法,得到了近似算法的一个估计. 相似文献