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21.
闻小永 《原子与分子物理学报》2007,24(6):1171-1175
通过函数变换和扩展Jacobi椭圆函数展开法,利用吴消元法,借助符号运算软件Maple,得到非线性Schringer方程丰富的包络形式精确解,特别是由两个Jacobi椭圆函数表示的精确解.当模数m→1或m→0时,一部分解退化为双曲函数或三角函数表示的解,F-展开法和扩展的F-展开法得到的精确解是本文结果的特例. 相似文献
22.
Omar Ramadan 《International Journal of Infrared and Millimeter Waves》2007,28(1):113-119
Unconditionally stable complex envelope (CE) perfectly matched layer (PML) absorbing boundary conditions (ABCs) are presented
for truncating the scalar wave-equation finite difference time domain (WE-FDTD) grids. The formulations are based on incorporating
the alternating direction implicit (ADI) scheme into the CE FDTD implementations of the scalar wave-equation derived in the
PML region at the domain boundaries. Numerical example carried out in two dimensional domain shows that the proposed formulations
are more accurate than the classical ADI scalar wave equation PML formulations when it is used for modelling band limited
electromagnetic applications. 相似文献
23.
Xianfu Wang 《Journal of Mathematical Analysis and Applications》2010,368(1):293-310
Associated to a lower semicontinuous function, one can define its proximal mapping and farthest mapping. The function is called Chebyshev (Klee) if its proximal mapping (farthest mapping) is single-valued everywhere. We show that the function f is 1/λ-hypoconvex if its proximal mapping Pλf is single-valued. When the function f is bounded below, and Pλf is single-valued for every λ>0, the function must be convex. Similarly, we show that the function f is 1/μ-strongly convex if the farthest mapping Qμf is single-valued. When the function is the indicator function of a set, this recovers the well-known Chebyshev problem and Klee problem in Rn. We also give an example illustrating that a continuous proximal mapping (farthest mapping) needs not be locally Lipschitz, which answers one open question by Hare and Poliquin. 相似文献
24.
Gorenstein flatness and injectivity over Gorenstein rings 总被引:1,自引:0,他引:1
Let R be a Gorenstein ring.We prove that if I is an ideal of R such that R/I is a semi-simple ring,then the Gorenstein flat dimension of R/I as a right R-module and the Gorenstein injective dimension of R/I as a left R-module are identical.In addition,we prove that if R→S is a homomorphism of rings and SE is an injective cogenerator for the category of left S-modules,then the Gorenstein flat dimension of S as a right R-module and the Gorenstein injective dimension of E as a left R-module are identical.We also give some applications of these results. 相似文献
25.
I-Chiau Huang 《Transactions of the American Mathematical Society》2001,353(8):3097-3114
A subcomplex of a residual complex on projective space is constructed for computing the cohomology modules of locally free sheaves. A constructive new proof of the Bott formula is given by explicitly exhibiting bases for the cohomology modules.
26.
Let R be a ring and S a class of R-modules. S-superfluous epimorphisms and S-essential monomorphisms are introduced and studied in this article. As appli-cations, some new characterizations of yon Neumann regular rings and perfect rings are given. Finally, these notions are also used to study minimal homomorphisms. 相似文献
27.
The study of mechanical systems with uncertain parameters is gaining increasing interest in the field of system analysis to provide an expedient model for the prediction of the system behavior. Making use of the Transformation Method, the uncertain parameters of the system are modeled by fuzzy numbers in contrast to random numbers used in stochastic approaches. As a result of this analysis, a quantification of the overall uncertainty of the system outputs, including a worst-case scenario, is obtained. The inputs of the resulting fuzzy-valued model are a priori uncorrelated but after the uncertainties are propagated through the model, interdependency (or interaction) between the outputs may arise. If such interdependency is neglected, a misinterpretation of the results may occur. For example, in the case of applying uncertainty analysis in the early design phase of a product to determine the relevant design-parameter space, the interdependency between the design variables may reduce significantly the available part of the design space. This paper proposes a measure of interdependency between the uncertain system outputs. The interdependency index can be derived by a postprocessing of the data gained by the analysis with the Transformation Method. Such information can be obtained by a negligible amount of extra computation time. 相似文献
28.
FENG Lianggui 《中国科学A辑(英文版)》2000,43(6)
For a commutative ring R, its related characterizations are given by investigating the structure and properties of H0R. Furthermore, by virtue of H0 structure, some important characterizations of CPF properties and connected properties on K0R are obtained from related rings. 相似文献
29.
Lianggui Feng 《中国科学A辑(英文版)》2000,43(6):568-573
For a commutative ringR, its related characterizations are given by investigating the structure and properties ofH
0
R. Furthermore, by virtue ofH
0 structure, some important characterizations of CPF properties and connected properties onK
0
R are obtained from related rings. 相似文献
30.
我们研制了CEBQ程序和ENVLOP程序,模拟稳态相对论电子束在二极管区的产生和加速,以及电子束在阳极通道内的传输过程。CEBQ程序模拟二极管区电子轨道,当阳极电压为1.5MV时,阴极总发射电流为17.9kA,进入阳极通道内的传输电流为4.3kA,阳极入口处D=4cm的束发射度为24.9cm.mrad。ENVLOP程序使用线性近似下的包络方程,描述电子束包络在螺旋管引导磁场作用下的变化,讨论了外加引导磁场对包络的影响。计算结果表明,在合适引导磁场作用下,束包络起伏较小,进入阳极通道的束流(4.3kA)能全部通过。 相似文献