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991.
We have investigated the dispersion forces effects in the instability of polystyrene films within the framework of the frequency-dependent theory. The calculated results of excess free energy, wavelength and growth rate show that the stability of the film can be tuned by the properties and the variation of the thickness of the coating. As the film thickness increases, the retardation effects can be significant and the full results of free energy must be used to deal with the instability of the polystyrene films. 相似文献
992.
ZHANG Duan-Ming SU Xiang-Ying YU Bo-Ming LI Rui PAN Gui-Jun SUN Hong-Zhang YIN Yan-Ping SUN Fan HE Min-Hua LIU Dan 《理论物理通讯》2005,44(3):551-554
We present a non-uniform granular system in one-dimensional case, whose granularity distribution has the fractal characteristic. The particles are subject to inelastic mutual collisions and obey Langevin equation between collisions. By Monte Carlo simulation we study the dynamic actions of the system. Far from the equilibrium, i.e., τ 〉〉 τe, the results of simulation indicate that the inhomogeneity of the system and the inelasticity of the particles have great influences on the dynamic properties of the system, and correspondingly the influence of the inhomogeneity is more significant. 相似文献
993.
Certain activities which would constitute infringement of a U.S. patent can come within a statutory exemption when the activity is carried out to obtain FDA approval. Exemptions to infringement provided by 35 U.S.C. §271(e)(1) are discussed along with recent cases interpreting this statute. The evolution of the statute in providing an exemption to activities necessary to obtain FDA marketing approval is described to provide background, legislative intent and show a comparative of the law before and after 1984 when 271(e)(1) was enacted. By analyzing recent cases, criteria for qualifying an activity as exempt from infringement are described – as are activities that do not qualify for the 271(e)(1) exemption. Overall there appears to be a trend to more broadly allowing for activities to qualify as exempt from infringement. This trend may affect the value of patents and determine which technologies a company will seek patent protection on. 相似文献
994.
M. S. Sodha S. C. Kaushik V. K. Tripathi 《Applied Physics A: Materials Science & Processing》1974,3(2):141-148
The free carrier nonlinear dielectric constant of a degenerate electron-hole plasma (e.g., Ge) in the presence of a Gaussian
electromagnetic beam has been studied by a kinetic treatment. The redistribution of carriers (electrons and holes) is the
source of nonlinearity and is effective in causing the self-focusing of the beam. The rise in carrier temperature due to the
wave field is almost unaffected by the degeneracy, whereas the nonlinearity is considerably affected by it. The increase of
degeneracy (by increasing the equilibrium carrier concentration at the fixed lattice temperature) increases the nonlinear
dielectric constant. Hence self-focusing is enhanced by degeneracy.
This work was supported by NSF (USA) and CSIR (India). 相似文献
995.
S. Tanzilli W. Tittel H. De Riedmatten H. Zbinden P. Baldi M. DeMicheli D.B. Ostrowsky N. Gisin 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,18(2):155-160
We report on energy-time and time-bin entangled photon-pair sources based on a periodically poled lithium niobate (PPLN) waveguide.
Degenerate twin photons at 1 314 nm wavelength are created by spontaneous parametric down-conversion and coupled into standard
telecom fibers. Our PPLN waveguide features a very high conversion efficiency of about 10-6, roughly 4 orders of magnitude more than that obtained employing bulk crystals [#!Tanzilli01a!#]. Even if using low power
laser diodes, this engenders a significant probability for creating two pairs at a time - an important advantage for some
quantum communication protocols. We point out a simple means to characterize the pair creation probability in case of a pulsed
pump. To investigate the quality of the entangled states, we perform photon-pair interference experiments, leading to visibilities
of 97% for the case of energy-time entanglement and of 84% for the case of time-bin entanglement. Although the last figure
must still be improved, these tests demonstrate the high potential of PPLN waveguide based sources to become a key element
for future quantum communication schemes.
Received 13 July 2001 相似文献
996.
双模问题rad~t(-,-)与拟遗传代数 总被引:4,自引:0,他引:4
设 B是 Krull-schmidt范畴 K上的一个上三角双模,Brustle和 Hille证明了B的矩阵范畴matB的投射生成子P的自同态代数的反代数A是拟遗传代数,而且代数A的△-好模范畴与matB等价.本文把这些结果推广到由Crawley-Boevey给出的具有非零导子的双模上,并在此基础上着重讨论了遗传代数 的投射模范畴Proj上的双模radt(-,-),刻画了它所对应的拟遗传代数的Gabriel箭图与关系,以及它们的特征模和Ringel对偶. 相似文献
997.
我们给出了一种统一的Jacobi椭圆函数方法来构造非线性偏微分方程精确行波解的新方法.借助于Mathematica,我们获得了五阶变系数模型方程的24种Jacobi椭圆函数解. 相似文献
998.
In this paper, a further investigation for the number of Derangements and Bell numbers is performed, and some new recursion formulae for the number of Derangements and Bell numbers are established by applying the generating function methods and Padé approximation techniques. Illustrative special cases of the main results are also presented. 相似文献
999.
Dr. Rainer Beck 《Physik in unserer Zeit》2016,47(4):168-175
1000.
S. Albeverio S. Kuzhel S. Torba 《Journal of Mathematical Analysis and Applications》2008,338(2):1267-1281
A p-adic Schrödinger-type operator Dα+VY is studied. Dα (α>0) is the operator of fractional differentiation and (bij∈C) is a singular potential containing the Dirac delta functions δx concentrated on a set of points Y={x1,…,xn} of the field of p-adic numbers Qp. It is shown that such a problem is well posed for α>1/2 and the singular perturbation VY is form-bounded for α>1. In the latter case, the spectral analysis of η-self-adjoint operator realizations of Dα+VY in L2(Qp) is carried out. 相似文献