二维等熵流的线性化方程的具轴对称初值的柯西问题

The explicit solution to Cauchy problem for linearized system of two-dimensional isentropic flow with axisymmetrical initial data in gas dynamics is given.     

Effect of a Small Current Quark Mass on Bag Constant

A method for obtaining the small current quark mass effect on the dressed quark propagator within the Dyson Schwinger approach is developed. From this the small current quark mass dependence of the bag constant is evaluated. It is found that the bag constant decreases with the increasing current quark mass and the contribution of the current quark mass cannot be dropped.     

A family of high-order accuracy explicit difference schemes with branching stability for solving 3-D parabolic partial differential equation

ＩｎｔｒｏｄｕｃｔｉｏｎＷｅｏｆｔｅｎｍｅｅｔｔｈｅｐｒｏｂｌｅｍｏｆｓｏｌｖｉｎｇｅｑｕａｔｉｏｎｏｆｐａｒａｂｏｌｉｃｔｙｐｅｉｎｍａｎｙｆｉｅｌｄｓｓｕｃｈａｓｓｅｅｐａｇｅ ,ｄｉｆｆｕｓｉｏｎ ,ｈｅａｔｃｏｎｄｕｃｔｉｏｎａｎｄｓｏｏｎ .Ｉｎｔｈｅｃａｓｅｏｆ3＿ｄｉｍｅｎｓｉｏｎ ,ｔｈｅｍｏｄｅｌｉｓａｎｉｎｉｔｉａｌａｎｄｂｏｕｎｄａｒｙｖａｌｕｅｐｒｏｂｌｅｍａｓｆｏｌｌｏｗｓ: ｕ ｔ = 2 ｕ ｘ2 2 ｕ ｙ2 2 ｕ ｚ2 　　　　 (0 <ｘ,ｙ,ｚ<1 ;ｔ>0 ) ,ｕ(ｘ ,ｙ,ｚ,0 ) =φ(ｘ ,ｙ ,ｚ)…     

三维抛物型方程的一族高精度分支稳定显格式

构造了一族解三维抛物型方程的高精度显格式,其稳定性条件为r=Δt/Δx2=Δt/Δy2=Δt/Δz2<1/2,截断误差为O(Δt2+Δx4).     

解抛物型方程的分支稳定的高精度显式差分格式

用待定参数法构造了解一维抛物型方程的分支稳定的高精度显式差分格式,截断误差为O（△t^4△x^4),稳定性条件为r=a△t/△x^2＜1/2。     

Nonclassical Potential Symmetries and New Explicit Solutions of Burgers Equation

A new method is used to determine the nonclassical potential symmetry generators of Burgers equation.Some classes of new explicit solutions, which cannot be obtained by Lie symmetry group of Burgers equation or its integrated equation, are obtained by using these new nonclassical potential symmetry generators.     

Explicit square conserving schemes of Landau-Lifshitz equation with Gilbert component

1　IntroductionandProblemsTotheordinarydifferentialequationsdY dt=A(t,Y)Y ,Y∈Rn,t≥ 0 ,( 1 )A(t,Y)isskewsymmetrymatrix .Fromd(YTY) dt=(Y′) TY YTY′=YT(AT A)Y =0 ,and‖Y( 0 )‖ =a ,aisapositivenumber,wecanget‖Y(t)‖ =a .Totheordinarydifferentialequationsofthesquareconservingproperty ( 1 ) ,classicalnumericalmethods,suchasexplicitRunge_Kuttamethods,multiplestepmethods,cannotpreservethesquareconservingproperty.Theimplicitmiddleschemecanpreservethesquareconservingproperty ,butitis…     

拉伸半无限圆孔板的应力集中系数表达式

首次推出拉伸半无限圆孔板孔边最大应力集中系数的显式表达式,此式不但形式简单而且具有良好的精度,目前献中尚无类似表达式。同时指出,Jeffery给出的仅有的几个具体理论值在圆孔比较靠近直线边界时误差较大。此外,采用本新定义的应力集中系数,当圆孔非常靠近直线边界时有一个极限值。     

近三正则3—连通平面地图的计数

本文提供了便于依根点次,边数和根面次计数近三正则3－连通有根平面地图的一个函数方程,继之得到其参数形式解,并由此通过Lagrange反演导出了它的计数显示,本文推广了[3]和[4]的结果。     

对流扩散方程的一种显式有限体积——有限元方法

本文给出非线性对流扩散问题的一种有限体积的有限元方法相结合的显式离散方法,证明了数值解的稳定性,并给出了一个实际算例。