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121.
Let G be a finite k‐edge‐connected simple graph. We consider when a set of independent edges can be extended to a 2‐factor such that this 2‐factor avoids a fixed set of independent edges. A complete characterization is provided in those cases, where this is feasible. © 2005 Wiley Periodicals, Inc. J Graph Theory 49: 48–58, 2005  相似文献   
122.
Four-point bend specimen is one of the most important specimens of the fracture mechanics because it can produce mixed modes I and II. Therefore, computation of stress intensity factors in this specimen is of practical interest. Several relations have been suggested that no one of them has completely considered the effects of the loading point and crack geometry. In this paper, mixed mode stress intensity factors of the bend specimen are computed by finite element method (FEM) and after validating by comparing with the available results in the literature, the results will be assessed to determine the effects of different crack location and loading distances from the middle of the specimen. Finally, two new coefficients comprising these effects are introduced.  相似文献   
123.
124.
针对知识产权屡禁不止的侵权行为现状,运用模糊数学、数理统计方法和博弈论原理,从知识产权保护和侵犯双方效用及模型出发,以系统和动态的视角对双方行为进了博弈分析.研究结果表明保护与侵犯构成为一对均衡策略状态,其主要原因在于一定条件下,保护方期望的效用均衡处于低水平态势,从而提出在效用模糊因子的调整中不断提高保护方的动态效用水平是推进有效保护知识产权的动力途径.  相似文献   
125.
本文研究在预报更新环境下具有快、慢两种配送方式和需求预报更新的库存系统,为了得到更多关于费用参数和预报改进对最优定货量以及最优的平均费用的影响,我们考虑两个周期的情形.以动态规划为工具我们得到了系统的最优策略.对于需求预报服从均匀分布情形,本文得到了最优定货量和最优的平均总费用的精确表达式.我们通过一些数值例子来说明库存费用、罚金、需求的预报改进和预报误差对最优定货量和最优的  相似文献   
126.
The aim of this paper is to introduce and investigate the concept of pseudo-atoms of a real-valued function m defined on an effect algebra L; a few examples of pseudo-atoms and atoms are given in the context of null-additive, null-null-additive and pseudo-null-additive functions and also, some fundamental results for pseudo-atoms under the assumption of null-null-additivity are established. The notions of total variation |m|, positive variation m+ and negative variation m of a real-valued function m on L are studied elaborately and it is proved for a modular measure m (which is of bounded total variation) defined on a D-lattice L that, m is pseudo-atomic (or atomic) if and only if its total variation |m| is pseudo-atomic (or atomic). Finally, a Jordan type decomposition theorem for an extended real-valued function m of bounded total variation defined on an effect algebra L is proved and some properties on decomposed parts of m such as continuity from below, pseudo-atomicity (or atomicity) and being measure, are discussed. A characterization for the function m to be of bounded total variation is established here and used in proving above-mentioned Jordan type decomposition theorem.  相似文献   
127.
Scaling factors for obtaining fundamental vibrational frequencies from harmonic frequencies calculated at six of the most commonly used levels of theory have been determined from regression analysis for the polarized-valence triple-zeta (pVTZ) Sadlej electric property basis set. The Sadlej harmonic frequency scaling factors for first- and second-row molecules were derived from a comparison of a total of 900 individual vibrations for 111 molecules with available experimental frequencies. Overall, the best performers were the hybrid density functional theory (DFT) methods, Becke's three-parameter exchange functional with the Lee–Yang–Parr fit for the correlation functional (B3-LYP) and Becke's three-parameter exchange functional with Perdew and Wang's gradient-corrected correlation functional (B3-PW91). The uniform scaling factors for use with the Sadlej pVTZ basis set are 0.9066, 0.9946, 1.0047, 0.9726, 0.9674 and 0.9649 for Hartree–Fock, the Slater–Dirac exchange functional with the Vosko–Wilk–Nusair fit for the correlation functional (S-VWN), Becke's gradient-corrected exchange functional with the Lee–Yang–Parr fit for the correlation functional (B-LYP), B3-LYP, B3-PW91 and second-order M?ller–Plesset theory with frozen core (MP2(fc)), respectively. In addition to uniform frequency scaling factors, dual scaling factors were determined to improve the agreement between computed and observed frequencies. The scaling factors for the wavenumber regions below 1800 cm−1 and above 1800 cm−1 are 0.8981 and 0.9097, 1.0216 and 0.9857, 1.0352 and 0.9948, 0.9927 and 0.9659, 0.9873 and 0.9607, 0.9844 and 0.9584 for Hartree–Fock, S-VWN, B-LYP, B3-LYP, B3-PW91 and MP2(fc), respectively. Hybrid DFT methods along with the Sadlej pVTZ basis set provides reliable theoretical vibrational spectra in a cost-effective manner. Received: 22 May 2000 / Accepted: 30 August 2000 / Published online: 28 February 2001  相似文献   
128.
We study electron-atom scattering in the presence of a laser field with elliptic polarization. We discuss the dependence of the differential cross sections for the cases of circular and linear polarizations as a function of scattering angle. Interesting typical signatures of the phase between the two components of the circular polarization of the laser field appear in the differential cross section.  相似文献   
129.
P Basu  V K Gupta  V S Bhasin 《Pramana》1989,32(1):13-32
A model forN-N interaction proposed earlier by two of us (VSB and VKG), has been extended to incorporate the tensor component of the nuclear force. Based on the quark compound bag model (QCB), the nucleon-nucleon potential has a short range repulsive core which is non-local and has a characteristic energy dependence and is expressed in terms of the parameters relating to the six-quark compound bag. To account for the low energy properties, this repulsive core interaction is supplemented by a phenomenological non-local potential containing both central (S-wave) and tensor components and operates only outside the QCB. Using this model, we analyse and compare the results with the experimental data for the electromagnetic form factors of the deuteron, theD-state observables, such as the quadrupole moment, theD-state probability, and theD/S ratio along with then-p scattering phase shifts up to about 400 MeV.  相似文献   
130.
An in-depth investigation is made on the problem of an arc-shaped interface insulating crack in a three-phase concentric circular cylindrical piezoelectric composite constitutive model. An exact solution in series form is derived by employing the complex variable method. In addition, the distribution of physical quantities such as stresses, strains, electric displacements and electric fields in the whole field and along the interface is also presented. Explicit expressions for crack opening displacement, jump in electric potential on the crack surface and the electro-elastic field intensity factors at the crack tips are obtained. Specific calculations demonstrate that the convergence of the series form solution is satisfactory and that the outer phase (composite phase) will exert a significant effect on the electro-mechanical coupling response of the composite system. Owing to the fact that stresses and electric displacements still possess conventional inverse square root singularities, the oscillating singularities near the crack tip under plane strain conditions will be absent and, as a result, no unphysical interpenetration phenomenon of the two crack surfaces will occur. In conclusion, the elastic solution obtained is also based on a solid physical foundation. Project supported by the National Natural Science Foundation of China (No.59635140), and the Doctorate Foundation of Xi'an Jiaotong University.  相似文献   
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