Axioma for Mach's Mechanics

We present an axiomatic framework for what we call Mach's mechanics, inspired on the ideas by A. K. T. Assis and P. Graneau about relational mechanics. We show that, in contrast to a suggestion of these authors, Mach's principle does not need to be committed with any Weber's like gravitational force. Actually it is possible to settle an axiomatic framework for non-relativistic classical particle mechanics which incorporates Mach's principle and is still consistent with any force that obeys the Newtonian action-reaction principle. We make further criticisms concerning relational mechanics.     

倾斜煤柱稳定性的弹塑性分析

考虑煤体的塑性软化性质,通过极限平衡法分析了煤层倾角对煤柱稳定性的影响,并通过产例验证了该法的合理性。     

Weakened acute type condition for tetrahedral triangulations and the discrete maximum principle

We prove that a discrete maximum principle holds for continuous piecewise linear finite element approximations for the Poisson equation with the Dirichlet boundary condition also under a condition of the existence of some obtuse internal angles between faces of terahedra of triangulations of a given space domain. This result represents a weakened form of the acute type condition for the three-dimensional case.

     

Black Holes Are One-Dimensional

The holographic principle has revealed that phyical systems in 3-D space, black holes included, are basically two-dimensional as far as their information content is concerned. This conclusion is complemented by one sketched here: as far as entropy or information flow is concerned, a black hole behaves as a one-dimensional channel. We define a channel in flat spacetime in thermodynamic terms, and contrast it with common entropy emitting systems. A black hole is more like the former: its entropy output is related to the emitted power as it would be for a one-dimensional channel, and disposal of an information stream down a black hole is limited by the power invested in the same way as for a one-dimensional channel.     

探讨制定物理教学仪器标准应遵循的原则

教学仪器的标准是保障教学仪器为教学服务的准绳,是教学仪器技术性能的基础。本文从物理教学仪器的教育功能出发,研究、探讨制订物理教学仪器标准应遵循的原则。     

模拟心电原理与变化电场的紧密联系

论述了心电向量环与模拟心电的紧密联系,突出了实验装置盘中心电向量环的医学意义及模拟心电的物理含义,论述了模拟心电原理与变化电场的紧密联系,阐述了实验盘综合变化电场形成的过程,详述了模拟心电图形成的物理机制。     

A Gradient Estimate for Solutions of the Heat Equation II

The author obtains an estimate for the spatial gradient of solutions of the heat equation, subject to a homogeneous Neumann boundary condition, in terms of the gradient of the initial data. The proof is accomplished via the maximum principle; the main assumption is that the sufficiently smooth boundary be convex.     

FINITE ELEMENT APPROXIMATION OF A NONLINEAR STEADY-STATE HEAT CONDUCTION PROBLEM

1. Introduction Anciellt Chinese mathematicians have done many fund~al discoveries, even thoughmad of them are now usually called by western names, e.g., the Pascal triangle, the HornerIcheme, the Gaussian elimination, see [231. In the modern era3 Chinese mathematiciare have.jalso got many priorities. For instance, the fast Proof Of convergence of the finite element methodfor a linear elliptic boundary vajue problem was done in the pioneering work [61 by K. Feng in1965 (for the English tra…     

基于变分原理的三维扩散方程离散化格式

研究三维扩散方程的数值模拟.在非正规六面体网格上,用变分原理建立扩散流形式的差分格式.将扩散流通量作为未知函数,求其泛函极值,并与原函数温度联立求解.详细推导了计算公式,并给出了数值试验结果.     

Force and pressure distribution under vibratory tillage tool

Experiments were conducted to study the force requirement and pressure distribution under vibratory tillage tools in a soil bin with a sandy loam soil. The tool was oscillated sinusoidally in the direction of soil bin travel. An octagonal ring transducer and pressure sensors were used to measure the forces and soil pressure on the blade. The tool was operated at oscillating frequency of 4.5–15.6 Hz and amplitude of 11–26 mm. The soil bin travel speed was varied from 0.05 to 0.224 m/s. The test results obtained showed both the horizontal force and the vertical force decreased with increase in oscillating frequency. The normal pressure on the blade surface varied considerably. The peak normal pressure was found to increase with increase in oscillating frequency, oscillating amplitude and soil bin travel speed. The change in average normal pressure with change in oscillating frequency and amplitude was also investigated.