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排序方式: 共有1901条查询结果,搜索用时 343 毫秒
161.
162.
163.
《偏微分方程通讯》2013,38(1-2):133-155
Abstract For regularized hard potentials cross sections, the solution of the spatially homogeneous Boltzmann equation without angular cutoff lies in Schwartz's space 𝒮(? N ) for all (strictly positive) time. The proof is presented in full detail for the two-dimensional case, and for a moderate singularity of the cross section. Then we present those parts of the proof for the general case, where the dimension, or the strength of the singularity play an essential role. 相似文献
164.
Raji Heyrovska 《Electroanalysis》2010,22(9):903-907
Aqueous standard potentials, referred to that of the SHE as zero, were recently shown to vary linearly with gaseous ionization potentials, with the absolute potential of SHE as the intercept. This enabled arriving at the absolute redox potentials of elements. Here, the distances between the oxidized and reduced forms in aqueous solutions have been evaluated. From the linear dependence of these distances on the covalent radii of atoms, the radii of the redox components have been obtained. The latter also vary linearly with the aqueous ionic radii estimated earlier from ion‐water distances, and indicate the presence of aqueous molecular anions. 相似文献
165.
黄博文 《首都师范大学学报(自然科学版)》2001,22(3):21-22,28
讨论了在超对称性量子力学中的平移形不变性和尺度(scaling)形不变性之间的关系,得到更加广义的形不变性。 相似文献
166.
The computed values of the temperature dependent electrical resistivity is presented for the alkaline earth metals Ca, Sr
and Ba. Numerical values of the mean free paths obtained using a finite mean free path approach is also reported. The structure
factor has been evaluated using experimental values for the phonon spectra while local model potentials were used for the
form factors. Our numerical results compare favourably with experiments. 相似文献
167.
Olga Choustova 《Journal of Mathematical Analysis and Applications》2008,346(1):296-304
We apply methods of quantum mechanics to mathematical modelling of price dynamics in a financial market. We propose to describe behavioral financial factors (e.g., expectations of traders) by using the pilot wave (Bohmian) model of quantum mechanics. Our model is a quantum-like model of the financial market, cf. with works of W. Segal, I.E. Segal, E. Haven. In this paper we study the problem of smoothness of price-trajectories in the Bohmian financial model. We show that even the smooth evolution of the financial pilot wave ψ(t,x) (representing expectations of traders) can induce jumps of prices of shares. 相似文献
168.
Fuping He Yiwang Chen Xiaohui He Muqing Chen Weihua Zhou Qing Wu 《Journal of polymer science. Part A, Polymer chemistry》2009,47(16):3990-4000
Vinyl‐type copolymerization of norbornene (NBE) and 5‐NBE‐2‐yl‐acetate (NBE‐OCOMe) in toluene were investigated using a novel homogeneous catalyst system based on bis(β‐ketonaphthylamino)Ni(II)/B(C6F5)3/AlEt3. The copolymerization behavior as well as the copolymerization conditions, such as the levels of B(C6F5)3 and AlEt3, temperature, and monomer feed ratios, which influence on the copolymerization were examined. Without combination of AlEt3, the catalytic bis(β‐ketonaphthylamino)Ni(II)/B(C6F5)3 exhibited very high catalyst activity for polymerization of NBE. Combination of AlEt3 in catalyst system resulted in low conversion for polymerization of NBE. For copolymerization of NBE and NBE‐OCOMe, involvement of AlEt3 in catalyst is necessary. Slight addition of NBE‐OCOMe in copolymerization of NBE and NBE‐OCOMe gives rise to significant increase of catalyst activity for catalytic system bis(β‐ketonaphthylamino)Ni(II)/B(C6F5)3/AlEt3. Nevertheless, excess increase of the NBE‐OCOMe content in the comonomer feed ratios results in decrease of conversion as well as activity of catalyst. The achieved copolymers were confirmed to be vinyl‐addition copolymers through the analysis of FTIR, 1H NMR, and 13C NMR spectra. 13C NMR studies further revealed the composition of the copolymer and the incorporation rate was 7.6–54.1 mol % ester units at a content of 30–90 mol % of the NBE‐OCOMe in the monomer feeds ratios. TGA analysis results showed that the copolymer exhibited good thermal stability (Td > 410 °C) and failed to observe the glass transitions temperature over 300 °C. The copolymers are confirmed to be noncrystalline by WAXD analysis results and show good solubility in common organic solvents. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3990–4000, 2009 相似文献
169.
An optimal control problem for an elliptic obstacle variational inequality is considered. The obstacle is taken to be the
control and the solution to the obstacle problem is taken to be the state. The goal is to find the optimal obstacle from H
1
0
(Ω) so that the state is close to the desired profile while the H
1
(Ω) norm of the obstacle is not too large. Existence, uniqueness, and regularity as well as some characterizations of the optimal
pairs are established.
Accepted 11 September 1996 相似文献
170.
We study the asymptotic behavior of the free energy for a model (defined by Sinai) of one-dimensional random walk with random potential. In particular, we obtain a central limit theorem and a strong law of large numbers for this free energy. We use some results on the free energy to study some sample path properties of this random walk which are related respectively to its recurrence and localization. Some exponents describing the recurrence and localization are found. 相似文献