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991.
992.
993.
The lowest-lying glueballs are investigated in lattice QCD using N_f = 2 clover Wilson fermions on anisotropic lattices. We simulate at two different and relatively heavy quark masses, corresponding to physical pion masses of mπ~938 MeV and 650 MeV. The quark mass dependence of the glueball masses has not been investigated in the present study. Only the gluonic operators built from Wilson loops are utilized in calculating the corresponding correlation functions. In the tensor channel, we obtain the ground state mass to be 2.363(39) GeV and 2.384(67)GeV at mπ~938 MeV and 650 MeV, respectively. In the pseudoscalar channel, when using the gluonic operator whose continuum limit has the form of ∈_ijkTrB_iD_jB_k, we obtain the ground state mass to be 2.573(55) GeV and 2.585(65) GeV at the two pion masses. These results are compatible with the corresponding results in the quenched approximation. In contrast, if we use the topological charge density as field operators for the pseudoscalar, the masses of the lowest state are much lighter(around 1 GeV) and compatible with the expected masses of the flavor singlet qq meson. This indicates that the operator ∈ijk TrBiDjBk and the topological charge density couple rather differently to the glueball states and qq mesons. The observation of the light flavor singlet pseudoscalar meson can be viewed as the manifestation of effects of dynamical quarks. In the scalar channel, the ground state masses extracted from the correlation functions of gluonic operators are determined to be around 1.4-1.5 GeV, which is close to the ground state masses from the correlation functions of the quark bilinear operators. In all cases, the mixing between glueballs and conventional mesons remains to be further clarified in the future. 相似文献
994.
成祥生 《应用数学和力学(英文版)》1993,14(5):417-428
This paper discusses the generalized variational principles founded by thetechnique of Lagrangian multipliers in structural mechanics and analyzes the nonlinearstatically indeterminate structures.It is assumed that the stress-strain relationship ofthe materials of structures has the form ofσ=Bε~(1/m)orτ=Cγ~(1/m),namely,thephysical equations of structures have the shape of exponential functions.Severalexamples are given to illustrate the statically indeterminate structures such as thetrusses,beams,frames and torsional bars. 相似文献
995.
成祥生 《应用数学和力学(英文版)》1990,11(7):697-702
This article discusses the problems of the dynamic computation for thin-walled structures such as thin plates and thin shells under impact load to find the dynamic factor mainly. In calculation we take into account the effect of the mass of the striking object and the system of thin-walled structures to be struck and transform the distributed mass of thin-walled structures into only one concentrated equivalent mass by the method of reduced mass. Accordingly we derive the dynamic factor for the system of thin-walled structures under impact load. 相似文献
996.
流体力学与晶体生长有密切的关系.在晶体生长中,流体中的输运过程和流动的不稳定性对生成晶体的结构和质量有重要影响.本文概述了晶体生长中与流体力学有关的若干问题.首先对晶体生长的一些基本方法作了简介,然后对晶体生长中的流动现象及其与晶体缺陷的关系进行了讨论,最后提出了几种控制流动以改进晶体生长技术的可能途径. 相似文献
997.
成祥生 《应用数学和力学(英文版)》1988,9(6):573-578
This paper discusses the problems of the bending, stability and vibrations of the rectangular plates with free boundaries
on elastic foundations. In the present paper we select a flexural function, which satisfies not only all the boundary conditions
of free edges but also the conditions at free corner points, and consequently we obtain a better approximate solution. The
energy method is used in this paper. 相似文献
998.
本文应用弹塑性小变形的假定,将应力与应变的关系都用变分形式相联系.简洁地导出板壳塑性屈曲的基本方程,并引入割线模量,计算较方便. 相似文献
999.
成祥生 《应用数学和力学(英文版)》1981,2(5):589-597
This paper gives the stress-strain relations of the variational types on the basis of an assumption concerning the small deformation in the theory of elasto-plasticity.The compact form of fundamental equations of plastic buckling of the plates and shells is obtained in terms of secant modulus. 相似文献
1000.
弹性地基上自由边矩形板的弯曲、稳定和振动 总被引:3,自引:0,他引:3
本文讨论了在弹性地基上自由边矩形板的弯曲、稳定和振动的问题.本文选择了一个挠曲函数,它不但能满足自由边的全部边界条件,而且也满足了自由角点的条件,从而得到了较好的近似解,文中使用了能量法. 相似文献