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A Monte Carlo method has been used for studying the effect of the motion of some submolecular structures on the migration of radical centres and on the free-radical decay and its dependence on density. Motions of crank, crankshaft, kink, and double kink type are considered. A cooperative type of motions is also taken into account. The results show that cooperative motions support diffusion of radical centres and thus also the free-radical decay but, at higher densities, the cooperation of motions is restricted. The density of the system, where the decay of radicals is followed, affects the rate of the decay, its increase causes radical decay retardation. This is in line with the high pressure effect, which also retards the radical decay rate. 相似文献
783.
F. Hoellinger B.J.P. Gall N. Schulz W. Urban I. Ahmad M. Bentaleb J.L. Durell M.A. Jones M. Leddy E. Lubkiewicz L.R. Morss W.R. Phillips A.G. Smith B.J. Varley 《The European Physical Journal A - Hadrons and Nuclei》1999,6(4):375-376
The very neutron-rich nucleus 138Te produced in the spontaneous fission of 248Cm has been investigated using the EUROGAM II %-ray multidetector array. The excited states of 138Te observed for the first time indicate that the region of ground state deformation beyond the doubly magic nucleus 132Sn has yet not been reached. 相似文献
784.
A newly developed infrared photoacoustic technique has been used to obtain information about the orientation of the surface functional groups of Kevlar-49R fibers. This method involves the use of a highly polarizable gas in the photoacoustic cell and comparison of the spectra with a non-polarizable coupling gas. A highly polarizable inert gas, xenon, enhances the surface modes oriented parallel to the surface and suppresses the intensity of the perpendicular modes. This method shows differences in the structure of the skin and the core of the fibers. The polymer chains in the skin are oriented parallel to the surface, and in the core they are almost radially oriented. 相似文献
785.
The Monte Carlo method was used for generation of amorphous polyethylene configurations on a diamond lattice. Chain building was performed on the tetrahedral lattice of edges 36, 62 and 43 Å with periodic boundary conditions imposed.32 chains were generated, each with a length of 100 CH2-groups (resulting density = 0.81 g·cm−3). Small spherical volumes with a radius of 10 Å were chosen at random from the total volume for the calculation of rotational barriers. The rotating bond was chosen to be close to the center of this sphere. We employed the method of molecular mechanics in order to calculate the rotational barriers. The calculation was made for 578 rotating bonds and the obtained distribution of rotational barriers is approximated by the corresponding Γ-distribution. 相似文献
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ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option. 相似文献