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171.
We investigate the effect of the alignment of the magnetic moments of Cooper pairs of charged quarks that form at high density in three-flavor quark matter. The high-density phase of this matter in the presence of a magnetic field is known to be the Magnetic Color-Flavor-Locked (MCFL) phase of color superconductivity. We derive the Fierz identities of the theory and show how the explicit breaking of the rotational symmetry by the uniform magnetic field opens new channels of interactions and allows the formation of a new diquark condensate. The new order parameter is a spin-1 condensate proportional to the component in the field direction of the average magnetic moment of the pairs of charged quarks. The magnitude of the spin-1 condensate becomes comparable to the larger of the two scalar gaps in the region of large fields. The existence of the spin-1 condensate is unavoidable, as in the presence of a magnetic field there is no solution of the gap equations with nonzero scalar gaps and zero magnetic moment condensate. This is consistent with the fact that the extra condensate does not break any symmetry that has not already been broken by the known MCFL gaps. The spin-1 condensate enhances the condensation energy of pairs formed by charged quarks and the magnetization of the system. We discuss the possible consequences of the new order parameter on the issue of the chromomagnetic instability that appears in color superconductivity at moderate density.  相似文献   
172.
王学水  马贺凯  王岩庆 《大学物理》2011,30(5):43-46,49
介绍了一种新的测量刚体转动惯量的实验方法与实验装置,在实验中,通过增加标准刚体试件,把细线拉力对转轴摩擦力矩的影响考虑进去,大幅度地提高了实验测试精度,另外,利用电力线载波通讯网络,将转动惯量测量仪采集的时间数据传输到PC机中,再经过PC机端数据处理软件,快速准确地将待测刚体的转动惯量以及其它与刚体有关的物理量计算、显...  相似文献   
173.
曾思良  倪飞飞  何建锋  邹士阳  颜君 《物理学报》2011,60(4):43201-043201
发展了一套简单高效的非微扰理论方法研究强磁场中的原子能级结构.作为例子,给出了磁场强度从0到1000个原子单位,氢原子基态和低激发态的结合能以及四极矩等重要原子能级结构参数.结果表明:相对于其他的高精度计算方法,该方法不仅能计算出高精度的能级位置而且可方便给出精确的电子波函数.此外,该法还具有很强的普适性,可直接推广到原子与任意方向的交叉电磁场相互作用的研究. 关键词: 强磁场 CWDVR谱方法 氢原子能级结构 四极矩  相似文献   
174.
Composite materials have been used in the design of the aircrafts structures because their low weight and high mechanical strength. However, structures made in composite material are exposed to dynamical and/or static loading environments. Therefore, a major research effort is undertaken in the development of tools numerical for analysis and design of composite structures. This paper presents a numerical formulation of the composite structures using the Finite Element Method (FEM). The damped composite structures, using inserted viscoelastic devices, and undamped composite structures are formulated by FEM. Viscoelastic materials are applied as continuous layers inserted on composite structures. The intrinsic damping of the composite material is included in the studies, too. The First‐order (FSDT) and Higher‐order Shear Deformation (HSDT) theories are formulated. They are distinguished by order of the approximation functions used in the mechanical displacements field. Both theories are computationally implemented using the Serendipity finite element. This is a rectangular finite element with 8 nodes, 5 or 11 degrees of freedom per node. The results are compared with papers predictions. The advantages and disadvantages of using each theory in the modeling of composite (thin or thick) and thick sandwiches structures, including the intrinsic and the viscoelastic damping, are discusses.  相似文献   
175.
It is well-known that the complete convergence theorem for i.i.d. random variables has been an active topic since the famous work done by Hsu and Robbins [6]. Chow [4]obtained a moment version of Hsu and Robbins series. However, the series tends to infinity whenever ∈ goes to zero, so it is of interest to investigate the asymptotic behavior of the series as ∈ goes to zero. This note gives some limit theorems of the series generated by moments for NA random variables.  相似文献   
176.
The aim of this article is to develop improved trial methods for the solution of a generalized exterior Bernoulli free boundary problem. At the free boundary, we prescribe the Neumann boundary condition and update the free boundary with the help of the remaining Dirichlet boundary condition. Appropriate update rules are obtained by expanding the state's Dirichlet data at the actual boundary via a Taylor expansion of first and second order. The resulting trial methods converge linearly for both cases, although the trial method based on the second order Taylor expansion is much more robust. Nevertheless, via results of shape sensitivity analysis, we are able to modify the update rules such that their convergence is improved. The feasibility of the proposed trial methods and their performance is demonstrated by numerical results.  相似文献   
177.
In this paper, we consider a class of nonlocal stochastic Kuramoto–Sivashinsky equations driven by additive noises. Under some appropriate conditions, we investigate long time behavior, i.e., stability and growth bounds of the solutions to the equation. Finally, several examples are given to illustrate our results.  相似文献   
178.
179.
Globally Hyperbolic Regularization of Grad's Moment System   总被引:1,自引:0,他引:1       下载免费PDF全文
In this paper, we propose a globally hyperbolic regularization to the general Grad's moment system in multidimensional spaces. Systems with moments up to an arbitrary order are studied. The characteristic speeds of the regularized moment system can be analytically given and depend only on the macroscopic velocity and the temperature. The structure of the eigenvalues and eigenvectors of the coefficient matrix is fully clarified. The regularization together with the properties of the resulting moment systems is consistent with the simple one‐dimensional case discussed in 1. In addition, all characteristic waves are proven to be genuinely nonlinear or linearly degenerate, and the studies on the properties of rarefaction waves, contact discontinuities, and shock waves are included. © 2014 Wiley Periodicals, Inc.  相似文献   
180.
相协样本半参数回归模型估计的矩相合性   总被引:1,自引:0,他引:1  
李军  杨善朝 《应用数学》2004,17(2):257-262
考虑半参数回归模型Y(j) (xin,tin) =tinβ g(xin) e(j) (xin) ,1 ≤j≤m ,1 ≤i≤n .利用最小二乘法和权函数估计方法 ,定义 β ,g的估计量βm ,n和gm ,n(x) ,在负相依样本及较弱的条件下证明了这些估计的矩相合性 ,这些结论推广和改进了胡舒合 ( 1 997)关于独立情形的相应结论 .  相似文献   
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