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991.
L. Báez-Duarte 《Journal of Theoretical Probability》1993,6(1):33-56
We prove two central limit theorems for real identically distribution random variables where the distribution is a complex-valued Borel measure . The results involve the weak convergence of the suitably scaledn-fold convolution of certain complex atomic or absolutely continuous measures of spectral radius 1 to ahypergaussian measure whose Fourier-Stieltjes transform is exp(–2 for a positive integer . The proof uses a generalization of the method of characteristic functions. Counter-examples are given to rather more general statements that had appeared previously in the literature. This research arose in connection with problems related to general tauberian theorems on the line for complexvalued summability methods which are discussed at the end of the paper. Some interesting examples are given generalizing well-known theorems related to Euler and Borel summability. 相似文献
992.
993.
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995.
Weibang Lu Jian Wu 《Acta Mechanica Solida Sinica》2009,22(4):283-286
Using the atomistic-based finite-deformation shell theory, we analytically investigate the coupling between the axial deformation and the torsion in single-wall carbon nanotubes. We find that the axial-strain-induced torsion(ASIT) response is limited only to chiral nanotubes. This response is affected by chiralities and radii of carbon nanotubes. Our results are similar to that of molecular dynamic simulations reported in the literatures. 相似文献
996.
997.
Free oscillations of a single spherical gas bubble in glycerol have been examined numerically and experimentally at different ambient temperatures and pressures. The bubble was generated using a Q-switched Nd:YAG laser and the unsteady radius measurement was based on a shadowing technique of a He–Ne laser beam. The measurements were compared to computations obtained from two models, first taking into consideration the liquid compressibility and then assuming an incompressible liquid domain, respectively. In both cases the temperature fields inside and outside the bubble were computed by solving the energy equation in both phases as the thermodynamic processes have great importance to the bubble behavior. For high amplitude oscillations the incompressible model provides poor agreement with the measurements and the modeling of the liquid compressibility becomes necessary. In contrast to the standard method, a practical region of applicability for the incompressible approach was determined as a function of the instantaneous Mach and Reynolds numbers, rather than specifying a simple threshold Mach number. 相似文献
998.
Jian Wu Seok Kim Andrew Carlson Chaofeng Lu Keh-Chih Hwang Yonggang Huang John A. Rogers 《力学快报》2011,1(1):011001
A mechanics model is developed for the contact radius of stamps with pyramid tips in transfer printing. This is important to the realization of reversible control of adhesion, which has many important applications, such as climbing robots, medical tapes, and transfer printing of electronics. The contact radius is shown to scale linearly with the work of adhesion between the stamp and the contacting surface, and inversely with the plane-strain modulus of the stamp. It also depends on the cone angle and tip radius of the stamp, but is essentially independent of details of the tip geometry. 相似文献
999.
The analytical transfer matrix method (ATMM) is applied to
calculating the critical radius $r_{\rm c}$ and the dipole
polarizability $\alpha_{\rm d}$ in two confined systems: the hydrogen
atom and the Hulth\'{e}n potential. We find that there exists a
linear relation between $r_{\rm c}^{1/2}$ and the quantum number $n_{r}$
for a fixed angular quantum number $l$, moreover, the three bounds
of $\alpha_{\rm d}$ ($\alpha_{\rm d}^{K}$, $\alpha_{\rm d}^{B}$,
$\alpha_{\rm d}^{U}$) satisfy an inequality:
$\alpha_{\rm d}^{K}\leq\alpha_{\rm d}^{B}\leq\alpha_{\rm d}^{U}$. A comparison
between the ATMM, the exact numerical analysis, and the variational
wavefunctions shows that our method works very well in the systems. 相似文献
1000.
We characterize those linear operators on triangular or diagonal matrices preserving the numerical range or radius. 相似文献