Elasticity of Space-Time: Basis of Newton’s 2nd Law of Motion

In this paper we derive Newton’s 2nd Law of Motion from the constitutive equation of elasticity of a space-time continuum in four dimensions. This we do by introducing a four-dimensional material continuum with a Minkowskian metric, in analogy with Einstein’s general theory of relativity. The four-continuum is deformable in both space and time. The physics of the deformation is embedded in a variational principle, which is a form-invariant extension of its classical mechanical counterpart in three dimensions, but with the acceleration term absent. General dynamic equations of elasticity in four dimensions are thereby derived. When the constraint of temporal inextensibility (universal time) is introduced, these equations yield readily the dynamic equations of elasticity in three dimensions. The presence of the inertia term in these equations, is a direct consequence of the temporal curvature induced by the deformation of the four-continuum. Newton’s law of motion for rigid bodies follows when the additional constraint of spatial inextensibility is introduced.     

Lyapunov analysis of the approximate motion equations of flexible structures

In this paper, the effectiveness of the approximate motion equations of a flexible structure, obtained by the RitzKantorovich method, is analysed by using Lyapunov functions. The analysis, which is restricted to the case of a single flexible beam for the sake of simplicity, is carried out under the assumption that a partial dissipation is present, affecting only the first degrees of freedom of the system. By means of suitable Lyapunov functions, an overbounding estimate of the quadratic approximation error is determined as a decreasing function of the approximation order. The analysis is completed by considering the two ‘extreme’ cases: the theoretical absence of dissipation and the presence of structural dissipation, affecting all the infinite degrees of freedom.     

Perceptually Grounded Language Learning: Part 2—DETE: A Neural/Procedural Model

In Part 1 of this two-part series, we introduced Katamic memory—a neural network architecture capable of robust sequence learning and recognition. In Part 2, we introduce the Blobs World taskjdomain for language learning and describe the DETE language learning system, which is composed of over 50 Katamic memory modules. DETE currently learns small subsets of English and Spanish via association with perceptual! motor inputs. In addition to Kaiamic memory, DETE employs several other novel features: (1) use of feature planes, to encode visual shapes, spatial relationships and the motions of objects, (2) phase-locking of neural firing, in order to represent focus of atention and to bind objects across multiple feature planes, and (3) a method for encoding temporal relationships, so that DETE can learn utterances involving the immediate past and future. We compare DETE to related models and discuss the implications of this approach for language-learning research.     

基于专家系统的机器人高层规划

本文介绍一个基于专家系统的机器人高层规划系统,阐述几个潜在应用子系统,并应用专家系统方法进行多机器人协调避碰运动规划。本系统具有良好的规划性能。     

如何辨别电影画原底片的优劣

本文提供一个简便实用的质量鉴定方法,用于在制作发行拷贝前,辨别电影画原底片的优劣。     

压缩机环状阀工作过程冲击应力的有限元分析研究

针对压缩机环状阀结构和运动特点,利用ANSYS分析软件对其冲击应力进行有限元分析,得出阀片质量和阀片倾侧运动对环状阀工作过程冲击应力的影响。为压缩机环状阀的结构修改和优化设计提供了必要的基础。     

旋风燃烧器冷态模型内颗粒运动轨迹计算

在冷态模型流场内，考虑气流对粉煤颗粒的气动阻力，建立其运动微分方程式。通过计算，得到九种粒径的颗粒在流场中的运动轨迹、停留时间、着膜位置和气－固相相对速度与该燃烧器几何参数和气动参数的关系，为燃烧器的深入研究提出了建议。     

期刊稿件网络采编系统的建立

《中国冶金》杂志社全面启用的科技期刊稿件采编系统是以Internet为载体，具有作者在线投稿、在线查询、上传校样、专家在线审理稿件、提交审稿意见、上传审改稿、编辑在线加工处理稿件等作用，完全实现了稿件从收稿到发稿的全程数字化管理，同时建立了数据齐全、操作简便的作者、审稿专家和稿件的数据库，改进了传统的操作方法和管理模式，提高了工作效率。杂志社采用该系统还可以进行网刊发布、管理以及期刊征订和发行处理。     

Electrolytic regeneration of bleach solution in the motion picture industry

Cyclic voltammetric and galvanostatic experiments have been carried out with both synthetic and commercial bleach solutions with a view to regenerating the same. Maximum efficiency could be achieved if the oxidation is carried out below an anodic potential of 0·80 V vs SCE. The data obtained in galvanostatic experiments with RCE confirm the results of the earlier technique.     

“磁约束”的防垢、除垢机理分析

讨论了轴对称非均匀磁场对带电粒子的作用，分析了“磁约束”对防垢、除垢的微观机理，指出满足磁约束理论的轴对称非均匀磁场的防垢，除垢效果好的原因，正是由于在这种磁场中，带电粒子的运动被约束在一定磁面上的某一磁感应线附近做以该磁感应线为中心的螺旋运动，且正、负离子的回旋方向相反，从而形成内部相互作用较弱的大分子簇团不易吸附在管壁上，达到防垢目的；磁化水的渗透压较大，可起到除垢效果。