32 research outputs found

    A Solution to Rigid Motion Applied in Differential Geometry: curves (Ⅰ)

    No full text
    刚体运动是物理中一个很理想的概念,即指一个物体在运动中,它的形状和大小不发生改变.在几何学里,刚体运动在某种意义上可以看作一种坐标变换.笔者刻画了正交标架与刚体运动的关系定理;作为应用,证明了在刚体运动下,作为确定一般空间曲线的形状和大小的完全不变量系统(弧长、曲率和挠率)保持不变;满足空间曲线的完全不变量系统的两条曲线可以重合.特别地,笔者总结出求两条给定曲线重合的刚体运动表达式的具体步骤,并给出一个实例加以阐述.n physics, a rigid body is an idealization of a solid body in which the shape and size remain constant regardless of external forces exerted on it. In geometry, a rigid motion is usually regarded as a coordinate transformation in certain sense. In this paper, the authors characterize the relation between orthogo- nal fames and rigid motion, and as its applications, they showed that under a rigid motion, the fully invari- ant algebraic systems (such as arc-length, curvature, torsion) determining the shape and size of a space curve can be preserved; and two given curves satisfying same fully invariant algebraic system can be coincided each other. Especially, the authors make an induction from a concrete example to illustrate how to solve a rigid motion such that two given space curves coincide together.广西自然科学资金项目(2011GXNSFA018127);广西民族大学重点科学研究项目(2012MDZD033

    Colloids in the study of fundamental physics

    No full text
    胶体颗粒在溶液中展现出丰富的类原子相行为.因此胶体体系被广泛用作研究相变过程的实验模型体系.在过去二三十年中,利用胶体体系,人们对结晶、成核、玻璃化转变和缺陷等基础物理现象做了大量的深入研究,并取得了丰富的成果.这些成果极大地拓展和完善了人们对各种相变现象的了解.本文对最近相关的研究进展和研究成果做了回顾和总结,对正在兴起的研究方向做了介绍,对未来可能的发展方向和面临的挑战做了简述.Colloidal particles in solution exhibit rich phase behaviors and behavior like "big-atom". In the past decades,as modelling systems, colloids have been widely employed in the study of nucleation, crystallization, glass transition and melting. A number of advances have been achieved. These advances to a large extent extend and complete the understanding of various phase transitions. Recently, a number of active fields are emerging with colloidal model systems. In this review, the advances and the emerging fields are summarized. At the end, the potential directions and the challenges for future studies are suggested.国家自然科学基金(批准号:11374218)资助的课题~

    内啮合曲线构型齿轮传动基本原理及接触分析

    No full text
    在齿轮传动共轭曲线理论研究的基础上,以内啮合曲线构型齿轮传动为对象,推导了沿给定接触角方向的空间共轭曲线副啮合方程,建立内啮合条件下空间共轭曲线副表达式,根据空间等距包络方法构建继承内啮合共轭曲线副特性的啮合齿面,通过改变成型曲面的相对运动位置及等距半径,提出凸齿廓-凸齿廓、凸齿廓-平面和凸齿廓-凹齿廓3种接触型式;以空间圆柱螺旋曲线为例,结合理论分析结果及主要设计参数,建立凸齿廓-凹齿廓内啮合曲线构型齿轮副三维实体模型;定义齿面接触点压力角,给出基于空间共轭曲线的齿面滑动率计算算法,完成内啮合齿面接触迹线计算及分析,后续将对齿面啮合性能、接触力学特性及制造方法进行研究

    水合物浆在管道中的流动安全

    No full text
    引言 20世纪30年代,在前苏联的天然气管道中首次发现了天然气水合物。自此之后随着石油工业的快速发展,天然气水合物对石油工业造成的影响也越来越大,尤其是从20世纪70年代开始,一些环境恶劣的油田(比如阿拉斯加北坡、西伯利亚、北海等)以及一些深海油田(比如墨西哥湾、西非、巴西等)逐渐投入生产,传统的水合物防治方法的缺陷更加明显,而且一些技术上的问题也限制了传统方法的使用
    corecore