Computer simulation on the collision-sticking dynamics of two colloidal particles in an optical trap

Collisions of a particle pair induced by optical tweezers have been employed to study colloidal stability. In order to deepen insights regarding the collision-sticking dynamics of a particle pair in the optical trap that were observed in experimental approaches at the particle level, the authors carry out a Brownian dynamics simulation. In the simulation, various contributing factors, including the Derjaguin-Landau-Verwey-Overbeek interaction of particles, hydrodynamic interactions, optical trapping forces on the two particles, and the Brownian motion, were all taken into account. The simulation reproduces the tendencies of the accumulated sticking probability during the trapping duration for the trapped particle pair described in our previous study and provides an explanation for why the two entangled particles in the trap experience two different statuses. (c) 2007 American Institute of Physics.

优化研究所内部环境的初步尝试

<正>力学所成立已34年,目前职工总人数逾800人,是力学科学的综合性研究大所。它面临着课题分散、人员及设备老化、资金紧张、住房紧张等一系列问题。如何走出困境,如何进一步完善综合性研究大所的运转机制,在竞争中寻求自身的生存与发展,是有待深入讨论研究和急需解决的重要问题。近年来,力学所在这些方面也进行了初步的探索和尝试。一、适当调整内部科研组织结构,建立跨室联合研究集体,增强研究所的竞争力和自身发展能力力学所原有13个研究室,基本上是按力学分支学科划分建立起来的,主要研究领域包括爆炸力学、物理力学、磁流力学和等离子体动力学、土力学、高速气体动力学、流体力学、空气动力学、高温气体动力学、固体力学、激光流体物理、跨声速空气动力学、材料力学性质、微重力科

守恒积分与奇性场的定解方程

本文利用守恒积分,对HRR奇性场的角分布函数作了进一步的探讨。证明了角分布函数满足两个函数方程。并由此导出几种新的定解方程。对于平面应变及平面应力的情况分别给出函数方程与定解方程的具体公式。最后针对若干典型情况,给出了不同定解方程的精确的数值计算结果,验证了在一般情况下不同定解方程的等价性。

用蒙特卡罗方法研究混合物模型

本文用蒙特卡罗方法计算了五种高密度二元混合物的压缩因子,并与两种解析的混合物模型的计算值进行了比较,结果表明单液范德瓦尔斯混合物模型的计算值更接近于蒙特卡罗方法的结果。

第2届全国疲劳学术会议

<正> 中国力学学会、中国航空学会、中国机械工程学会联合召开的第2届全国疲劳学术会议,于1984年10月8—11日在四川峨眉西南交通大学举行,参加会议代表150多人,宣读和交流126篇论文,并进行了专题讨论,论文内容大致包括以下几个方面。

Mulher, política e ação

Traz um relato do trabalho desenvolvido pela Comissão Especial destinada ao estudo das medidas legislativas que visem implementar, no Brasil, as decisões da IV Conferência Mundial da Mulher.

O papel da energia nas ações de mitigação

Descreve as alternativas energéticas que se colocam para mitigar boa parte das emissões de gases de efeito estufa (GEE) do planeta. Enfatiza o potencial para o uso mais eficiente da energia em todos os setores da economia e nas oportunidade de substituição de combustíveis fósseis por combustíveis renováveis. Ressalta a importância de mudança de hábitos de consumo para reduzir as emissões de GEE a níveis considerados seguros, de maneira a se estabilizarem as concentrações de gases na atmosfera em níveis suficientemente baixos.

Analysis of flexural vibration of viscoelastically damped sandwich plates

The simplified governing equations and corresponding boundary conditions of flexural vibration of viscoelastically damped unsymmetrical sandwich plates are given. The asymptotic solution of the equations is then discussed. If only the first terms of the asymptotic solution of all variables are taken as an approximate solution, the result is identical with that obtained from the Modal Strain Energy (MSE) Method. As more terms of the asymptotic solution are taken, the successive calculations show improved accuracy. With the natural frequencies and the modal loss factors of a damped sandwich plate known, one can calculate the response of the plate to various loads providing a reliable basis for engineering design.

[Discurso do Deputado Valério Magalhães : Sessão da Câmara dos Deputados de 14 de agosto de 1964]

Referência à palestra do economista Hélio Beltrão, cujo objetivo foi de despertar os setores responsáveis pela consolidação de Brasília. Condenação ao retorno de diversos órgãos federais para o Rio de Janeiro. Cita o artigo "Política de contenção" publicado no jornal Correio Braziliense sobre normas do Ministro da Fazenda que implicam na redução das verbas consignadas ao Distrito Federal.

采用偏置射流预燃室稳定燃烧水煤浆的原理及应用研究

水煤浆作为经济型清洁燃料引起人们的长期关注。水煤浆偏置射流预燃室具有对浆种适应性强，稳燃性能好等特点。本文对偏置射流预燃室稳定燃烧水煤浆的原理进行了探讨，并对该燃烧技术用于处理造纸黑液的研究情况作了介绍。结果表明，采用低压多级雾化喷嘴对水煤浆进行雾化，形成的雾炬和偏置射流预燃室的流场有良好的匹配，在预燃室内形成大尺度的回流区，有利于煤浆的点火、稳燃和消除灰渣。

激光智能制造系统中同步控制的实现

分析了激光智能制造系统中同步控制问题,利用现场总线机制和串口通讯机制实现控制计算机对机器人系统和激光器系统的同步控制;设计外围控制电路,实现在加工过程中控制计算机对系统的状态监视和故障处理;运用多线程程序机制设计应用程序,实现控制计算机对整个系统的实时与同步控制.所设计的系统运行稳定,满足了实际工程应用的要求.