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51.
AN IMPROVED NONLINEAR CLOSED GRAPH THEOREM 总被引:1,自引:0,他引:1
References: 《高校应用数学学报(英文版)》2007,22(2):226-228
In this paper, a new nonlinear closed graph theorem is established, whose result improves substantially a recent-known important conclusion. 相似文献
52.
Jun-Chen Su 《The European Physical Journal C - Particles and Fields》2006,47(3):757-783
A rigorous three-dimensional relativistic equation for quark–antiquark bound states at finite temperature is derived from
the thermal QCD generating functional which is formulated in the coherent-state representation. The generating functional
is derived newly and given a correct path-integral expression. The perturbative expansion of the generating functional is
specifically given by means of the stationary-phase method. Especially, the interaction kernel in the three-dimensional equation
is derived by virtue of the equations of motion satisfied by some quark–antiquark Green functions and given a closed form
which is expressed in terms of only a few types of Green functions. This kernel is very suitable to use for exploring the
deconfinement of quarks. To demonstrate the applicability of the equation derived, the one-gluon exchange kernel is derived
and described in detail.
PACS 05.30.-d, 67.40.Db, 11.15.-q, 12.38.-t, 11.10.St. 相似文献
53.
非完整约束系统中广义位移变分的选值域问题 总被引:4,自引:0,他引:4
本文讨论了非完整约束系统分析动力学中δq 选值域不同的情况,探讨了产生这种不同的力学原因,存此基础上,说明了非完整约束系统分析动力学中长期存在的难以说明的几个问题. 相似文献
54.
To realize the trajectory control of a flexible manipulator, a so-called virtual rigid manipulator is introduced to describe the specified trajectory. The recursive kinematics relations and dynamics equation in the form of variation are established. A recursive approach of inverse dynamics is developed, which is simple and has higher computation efficiency. A two-links planar flexible manipulator is studied to verify the effectiveness of the approach proposed.This work was supported by the National Natural Science Foundation of China and a Doctoral Program. 相似文献
55.
In this paper, we shall decompose the large-scale goal programming model with couple-block diagnal structure into several subproblems. We will also propose the definition of deviation sets. Relations of optimal solution between sub-problems and the large-scale problem will be discussed. The existence of optimal solution for large-scale goal programming will be considered.Research is supported by a grant of the National Natural Science Foundation of China. 相似文献
56.
掺镁铌酸锂晶体抗光损伤机理的研究 总被引:3,自引:1,他引:2
通过测试Mg(5mol%):LiNbO3、Mg(4m0l%):LiNbO3和LiNbO3等晶体的光损伤阈值、红外透射光谱、倍频性能等,研究了Mg2+在Mg:LiNbO3晶体中所处的状态以及高掺镁抗光损伤能力增强的机理。 相似文献
57.
Ti, Fe Co-doped LiTaO3 (LT) crystals have been grown by the Czochralski method from the congruent melts. The absorption spectra of crystal were measured before and after ultraviolet illumination. Holograms have been recorded in doubly doped crystals with continuous-wave laser light by use of two-color method. The maximum value of refractive-index changes 7×10−5 is achieved. 相似文献
58.
59.
The complete Breit potential contains the terms of spin-spin, spin-orbit, orbit-orbit, and tensor force interactions which become singular at short distance. Most of previous calculations of the non-relativistic potential quark model considered only the spin-spin interaction and substituted the $ \delta$ (r) -function by the Gaussian or Yukawa potential in coordinate space. Recently, a method to regularize the Breit potential consists of subtracting terms that cancel the singularity at the origin but leave the intermediate- and long-distance behavior unchanged. Motivated by this work we regularize the Breit potential by multiplying the singular terms in momentum space identically by the form factor [ $ \mu^{2}_{}$ /(q 2 + $ \mu^{2}_{}$ )]2 of the momentum transfer q , where the screened mass μ increases with the reduced mass of the meson. With the regularized Breit potential we calculate the masses of 30 common mesons and the new $ \eta_{b}^{}$ meson. We find that the calculated masses from light to heavy mesons agree well with experimental data. The inclusion of such a dependence of the reduced mass in the potential regularization improves the spin-spin splittings of $ \eta_{c}^{}$ -J/ $ \psi$ and $ \eta_{b}^{}$ - $ \Upsilon$ (1S) . The spin-orbit and tensor force interactions in the Breit potential lead to the splittings of $ \chi_{{c0}}^{}$ , $ \chi_{{c1}}^{}$ , and $ \chi_{{c2}}^{}$ . 相似文献
60.
为了充分发挥概率神经网络在企业财务危机预警中的作用,克服概率神经网络平滑参数难以确定和空间复杂度高的不足,本文提出一类新的参数动态调整的粒子群算法优化概率神经网络的平滑参数,进而采用改进粒子群算法优化初始隶属度矩阵的模糊聚类方法实现对样本的选择,解决了概率神经网络平滑参数的确定及空间结构复杂的问题。提出了基于改进粒子群算法的模糊聚类-概率神经网络企业财务危机预警模型,并以我国上市公司作为研究对象进行了实证研究。结果表明,经过模糊聚类和改进粒子群算法优化的概率神经网络具有更优的预测性能,并在企业财务危机长期预警方面具有一定效用。 相似文献