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951.
Kung-Chien Wu 《Journal of Mathematical Analysis and Applications》2010,365(2):584-589
This paper is devoted to the proof of the convergence from the modulated cubic nonlinear defocusing Klein-Gordon equation with magnetic field to the wave map equation. More precisely, we discuss the nonrelativistic-semiclassical limit of the modulated cubic nonlinear Klein-Gordon equation with magnetic field where the Planck's constant ?=ε and the speed of light c are related by c=ε−α for some α?1. When α=1 the limit wave function satisfies the wave map with one extra term coming from the magnetic field. However, α>1, the effect of the magnetic filed disappears and the limit is the typical wave map equation only. 相似文献
952.
The estimation of loss reserves for incurred but not reported (IBNR) claims presents an important task for insurance companies to predict their liabilities. Recently, individual claim loss models have attracted a great deal of interest in the actuarial literature, which overcome some shortcomings of aggregated claim loss models. The dependence of the event times with the delays is a crucial issue for estimating the claim loss reserving. In this article, we propose to use semi-competing risks copula and semi-survival copula models to fit the dependence structure of the event times with delays in the individual claim loss model. A nonstandard two-step procedure is applied to our setting in which the associate parameter and one margin are estimated based on an ad hoc estimator of the other margin. The asymptotic properties of the estimators are established as well. A simulation study is carried out to evaluate the performance of the proposed methods. 相似文献
953.
Bifurcation method of dynamical systems is employed to investigate traveling wave solutions in the (2 + 1)-dimensional Zakharov-Kuznetsov-Benjamin-Bona-Mahony equation. Under some parameter conditions, exact solitary wave solutions and kink wave solutions are obtained. 相似文献
954.
955.
用维纳滤波法复原闪光X光图片 总被引:1,自引:0,他引:1
本文对某系统拍摄的闪光X光模糊图片成功地进行了复原处理,把闪光X光照相系统简化为线性位移不变系统,建立了成像过程的数学模型;系统的退化效应用综合点扩展函数描述,并用针孔和台阶照相的方法进行测量;提出了校正图片上数据非线性及削弱图片中噪声的方法;采用维纳滤波方法作复原运算,给出了复原结果。 相似文献
956.
Xu Wu J. P. Denis G. Özen Ph. Goldner F. Pellé 《Applied physics. B, Lasers and optics》1993,56(5):269-273
A detailed study of the spectroscopic properties of the PbF2+GeO2:Er2O3 vitroceramic sample upon 650 nm excitation was investigated. The absorption, emission, excitation spectra, and time-resolved spectra have been measured. The up-conversion of red radiation (650 nm) into UV (368 nm and 379 nm), blue (406.8 nm) and green (522 nm and 540 nm) emissions is observed for Er3+ ions in the sample. The up-conversion process involves a two-photon absorption for the violet, blue, and green emission bands. A three-photon process happens for another violet (379 nm) band. 相似文献
957.
本文以Sampson旋转子在圆管中反演得到的无穷级数作为基本奇点,对分布函数采用离散奇点线分布法和分段二次抛物分布法,解决了任意轴对称体在无限长圆管中绕中心轴旋转的Stokes流动问題。通过对长球的数值计算,比较了两种方法,结果表明分段二次抛物分布法各方面都优于离散法。此外,本文还研究球串在无穷长圆管中绕中心轴旋转的小Re数问题,第一次给出了每个球所受的阻力矩系数。 相似文献
958.
本文研究了群柱内酯萜(Ⅰ)的二维1H同核COSY、C-H COSY、远距C-H COSY谱,根据这些信息和经验规律归属了(Ⅰ)的1H及13C谱峰,二维远距C-H COSY提供了相隔两、三个键的C-H偶合信息,因此,在很多方面可以代替灵敏度很低的INADEQUATE技术,得到C-C联结的信息。 相似文献
959.
(001)-oriented strontium bismuth tantalate thin films have been grown on Pt/TiO2/SiO2/Si (100) substrates by pulsed laser deposition. The room-temperature current–electric field dependence of the films has been
investigated, which revealed a space-charge-limited conduction mechanism. The microstructures of grain boundaries and structural
defects in these films were also examined by transmission electron microscopy and high-resolution transmission electron microscopy,
respectively. The grains of the films deposited at 550 °C exhibited polyhedral morphologies, and the average grain size was
about 50 nm in length and 35 nm in width. At a small misorientation angle (8.2°) tilt boundary, a regular array of edge dislocations
with about 3-nm periodic distance was observed, and localized strain contrast near the dislocation cores was also observed.
The Burgers vector b of the edge dislocation was determined to be [110]. At a high misorientation angle (39.0°) tilt grain boundary lattice strain contrast associated with the distortion of
lattice planes was observed, and the mismatching lattice images occurred at about 2 nm along the boundary. The relationship
between microstructural defects at grain boundaries and leakage currents of these films is also discussed.
Received: 8 September 2000 / Accepted: 18 December 2000 / Published online: 28 February 2001 相似文献
960.
用上下解方法和位势估计,研究Rn上具有次线性项加超线性项半线性椭圆方程给出了其有界正解的存在性、唯一性和渐近性质,其中为常数,参数. 相似文献