Si(111)2×1表面重构及1×1畴影响的LEED计算

长期以来Si(111)2×1重构表面的原子结构是个没有完全解决的问题。通过低能电子衍射(LEED)的全动力学的仔细计算,我们分析了以前提出的各种模型,肯定了皱曲的π-建链模型。进一步调整了表面六层原子的位置,使理论计算与实验结果符合得更好。我们最佳的2×1结构的最主要特点是表面链的倾斜达0.44?。最后,我们的计算指出在Si(111)2×1表面中1×1畴的存在对结果产生重大的影响。 关键词：     

快旋转中子星的相对论场方程的数值解 *

借助于数值解的方法,求解了在广义相对论框架下以任意角速度旋转的稳定中子星的结构方程 计算方法是利用了Neugebauer的最小表面形式体系,Einstein场方程等效于二维最小表面方程.对10种可能的中子星的物态方程,计算了在快旋转下稳定星体的结构,旋转对中子星的结构参量及各种性质的影响.根据我们的计算结果探讨了对中子星的物态方程的一些限制和快旋转中子星的稳定性等问题.     

包含相对论四极矩-四极矩相互作用的两体运动方程

利用DSX体系 ,借助于Maple计算机代数系统 ,得到了包含相对论的单极矩、自旋和四极矩间相互作用的两体的完整和明确的一阶后Newton近似运动方程 .这套运动方程同时被表示在局部参考系以及整体参考系中 .方程中新包含的四极矩 四极矩项对今后精确决定双中子星结合过程中的运动轨道也许是重要的     

Extending the First—Order Post—Newtonian Scheme in Multiple Systems to the Second—Order Contributions to Light Propagation

We extend the first-order post-Newtonian scheme in multiple systems presented by Damour-Soffel-Xu to the second-order contribution to light propagation without changing the virtue of the scheme on the linear partial differential equations of the potential and vector potential.The spatial components of the metric are extended to the second-order level both in a global coordinates(qij/c^4) and a local coordinates(Qab/c^4).The equations of qij(or Qab)are obtained from the field the field equations.The relationship between qji and Qab are also presented.In the special case of the solar system(isotropic condition is applied(qij=δijq)),we obtain the solution of q.Finally,a further extension of the second-order contributoions in the parametrized post-Newtonian formalism is discussed.     

Post-Newtonian perturbed theory of elastic astronomical bodies in rotating spherical coordinates

In this paper the dynamical equations for an elastic deformable body in the first post-Newtonian approximation of Einstein theory of gravity are derived in rotating spherical coordinates. The unperturbed rotating body (the relaxed ground state) is described as uniformly rotating, stationary and axisymmetric configuration in an asymptotically flat space-time manifold. Deviations from the equilibrium configuration are described by means of a displacement field. By making use of the schemes developed by Damour, Soffel and Xu, and by Carter and Quintana we calculate the post-Newtonian Lagrangian strain tensor and symmetric trace-free shear tensor. Considering the Euler variations of Einstein's energy-momentum conservation law, we derive the post- Newtonian energy equation and Euler equations of elastic deformable bodies in rotating spherical coordinates.