均质三角形边框刚体对其质心轴的转动惯量的简明推导

利用任意三角形的边长与顶点坐标的关系, 直接推出任意三角形边框的质心到各边中点的距离与三 角形各边边长的关系, 从而方便地求得任意均质三角形边框刚体对其质心轴的转动惯量     

匀质边框三角形刚体绕质心轴的转动惯量公式

确定了任意匀质边框三角形刚体的质心的几何位置;在此基础上推导出匀质边框三角形刚体绕质心轴的转动惯量公式,为计算三角形网格状边框刚体绕质心轴的转动惯量奠定了理论基础.     

任意多边形匀质刚板绕垂直板面质心轴的转动惯量的几何求法

利用改造后的平行轴定理,提出了一种推导任意多边形匀质刚板绕质心轴的转动惯量的几何方法,并用这种方法推导出任意三角形和五边形匀质刚板绕质心轴的转动惯量公式。     

刚体绕任意轴转动惯量的简便计算

利用微元求和的方法给出几种刚体对于过质心任意轴的转动惯量公式，并由此引出转动惯量与刚体几何对称性的联系，以及与转动惯量有关的几何形体等价性的一些结果．     

任意六边形匀质刚板绕垂直板面质心轴的转动惯量公式

提出任意六边形匀质刚板绕垂直板面质心轴的转动惯量的几何方法,并且给出了一些特例的转动惯量公式     

对称操作与量纲方法求刚体转动惯量

本文运用对称操作与量纲方法配合平行轴定理推导出非对称的任意三角形平板及平行四边形平板绕质心轴的转动惯量公式，从而避免了繁杂的积分．其特例正好是文献［１］的结果     

均质多边形薄板绕任一对角线转动的转动惯量

运用均质三角形薄板对任一边、对过顶点且与对边平行的轴的转动惯量公式,得到了用薄板的质量、边长及对角线长表示的均质多边形薄板对任一对角线的转动惯量.     

刚体绕任意轴转动惯量的简便计算

利用微元求和的方法给出几种刚体对于过质心任意轴的转动惯量公式，并由此引出转动惯量与刚体几何对称性的联系，以及与转动惯量有关的几何形体等价性的一些结果。     

分形物体转动惯量的计算

由分形物体的自相似性、转动惯量的量纲和平行轴定理,分别计算并得到分形三角形、分形正方体、分形四面体和科赫雪花的转动惯量.     

浅析椭圆盘及椭球体的转动惯量

给出椭圆盘和椭球体对于过质心任意轴的转动惯量公式的新形式,并由此导出椭圆和椭球的一种几何性质     

ON GEOMETRIC QUANTIZATION FOR BOSONIC STRING (Ⅱ)

The Hilbert space and the representation of the generators of Virasoro algebra for bosonic string under a holomorphic polarization are given in this paper,It is shown that the contre term of Virasoro algebra may be interpreted as curvature of a holomorphic vector bundle (holomorphic Fock bundle) on coset space G¹¹=G/H where G denotes the conformal transformation group and H the one-parameter subgroup generated by the generator L₀.The condition of the conformal anomaly cancellation may be expressed as the vanishing curvature of the bundle which is obtained by the product of the holomorphic Fock bundle and the holomorphic ghost vacuum bundle.The geometric interpretations of both classical and quantized BRST operators,ghost and antighost operators are also discussed.     

任意四边形刚体平板绕质心轴的转动惯量公式

本文给出了任意四边形刚体平板绕其质心轴的转动惯量公式，并在极限情形及对称条件下给出若干推论；均与已知结果相吻合。     

Vertex Operators, Grassmannians, and Hilbert Schemes

We approximate the infinite Grassmannian by finite-dimensional cutoffs, and define a family of fermionic vertex operators as the limit of geometric correspondences on the equivariant cohomology groups, with respect to a one-dimensional torus action. We prove that in the localization basis, these are the well-known fermionic vertex operators on the infinite wedge representation. Furthermore, the boson-fermion correspondence, locality, and intertwining properties with the Virasoro algebra are the limits of relations on the finite-dimensional cutoff spaces, which are true for geometric reasons. We then show that these operators are also, almost by definition, the vertex operators defined by Okounkov and the author in Carlsson and Okounkov ( [math.AG], 2009), on the equivariant cohomology groups of the Hilbert scheme of points on \mathbb C²{\mathbb C^2} , with respect to a special torus action.     

DYNAMIC RESPONSE OF A ROTATING FLEXIBLE ARM CARRYING A MOVING MASS

A clamped-free flexible arm rotating in a horizontal plane and carrying a moving mass is studied in this paper. The arm is modelled by the Euler-Bernoulli beam theory in which rotatory inertia and shear deformation effects are ignored. The assumed mode method in conjunction with Hamilton's principle is used to derive the equation of motion of the system which takes into account the effect of centrifugal stiffening due to the rotation of the beam. The eigenfunctions of a cantilever beam which satisfy the prescribed geometric boundary conditions are used as basis functions in the assumed mode method. The equation of motion is expressed in non-dimensional matrix form. Pre-designed transformed cosine profiles are used as trajectory inputs for the hub angle and the moving mass. The equation of motion is solved numerically using the fourth order Runge-Kutta method. Graphical results are presented to show the influence of centrifugal stiffening effect, moving mass values, mass travelling time, hub angle and mass trajectory profile on the deflection of the beam.