论陀螺的迴转稳定准则及其应用

本文以卡尔丹角为方位参量,建立了轴对称刚体(陀螺)永久转动情形的非线性稳定方程组。应用直接方法证明了具有完全耗散情形的陀螺迴转稳定准则:陀螺绕对称轴自由迴旋稳定的充要条件是转子呈扁形。这一准则不仅为陀螺仪设计提供理论依据,而且为飞行器用自旋稳定实现姿态控制提供理论依据。美国发射的Fxplorer-1号绕长轴自旋失稳和第一颗通讯卫星Syncon号绕短轴自旋取得姿态控制成功的事实都能依据这一准则得到合理解释。

Lei Geral da Copa

Lei nº 12.663, de 5 de junho de 2012, que "dispõe sobre as medidas relativas à Copa das Confederações Fifa 2013, à Copa do Mundo Fifa 2014 e à Jornada Mundial da Juventude 2013, que serão realizadas no Brasil; altera as Leis nos 6.815, de 19 de agosto de 1980, e 10.671, de 15 de maio de 2003; e estabelece concessão de prêmio e de auxílio especial mensal aos jogadores das seleções campeãs do mundo em 1958, 1962 e 1970", e legislação correlata.

有关压力传感器动态校准和动态性能评价的几个问题

在本文中,作者根据简单的线性系统分析和实践中的体会,对压力传感器的动态校准和动态性能的评价提出下列几点看法:(1)阶跃压力是较理想的动态校准压力源;激波管可以作为标准动态压力标准装置(微压传感器除外)。(2)压力传感器的主要动态性能指标为:上升时间、超调量、振荡频率或谐振频率、冲击加速度灵敏度。(3)压力传感器的校准可采用静态校准和动态校准相结合的方法,没有必要在整个量程范围内进行动态校准。用“动态灵敏度”来概括压力传感器的动态性能是不确切的。

稳态CO激光的解析理论

为了分析CO激光的特性,通常需要对上百个方程进行数值计算,因而解析的分析就成为一个很值得探讨的方面。本文从分布函数方程和辐射强度谱分量传输方程出发,导出稳态CO激光在级联跃迁发射时的增益饱和特性,得到的强度谱分量与增益的关系式适用于均匀和非均匀加宽同时起作用的一般情况。文中所使用的振动分布函数由一个非线性积分方程求得。对两能级特例,本文结果与文献[9]一致。对均匀加宽极限的特例,本文给出的强度和强度谱分量的关系式与文献[4]的结果一致。

平晶型激光错位干涉仪及其在流场测量中的应用

仪器的原理是将一束激光经扩束后通过被测系统,然后在平晶前后表面反射而获得干涉图.仪器防振性能好,可以方便地对横向与纵向尺寸都较大的流场进行测量,光源亮度高,结构简单,调整使用方便,有希望在流场测量特别是超声速流场测量中获得广泛的应用.

Experimental and theoretical study on numerical density evolution of short fatigue cracks

Fatigue testing was performed using a kind of triangular shaped specimen to obtain the characteristics of numerical density evolution for short cracks at the primary stage of fatigue damage. The material concerned is a structural alloy steel. The experimental results show that the numerical density of short cracks reaches the maximum value when crack length is slightly less than the average grain diameter, indicating grain boundary is the main barrier for short crack extension. Based on the experimental observations and related theory, the expressions for growth velocity and nucleation rate of short cracks have been proposed. With the solution to phase space conservation equation, the theoretical results of numerical density evolution for short cracks were obtained, which were in agreement with our experimental measurements.

A finite-element analysis of viscoelastically damped sandwich plates

A finite element analysis associated with an asymptotic solution method for the harmonic flexural vibration of viscoelastically damped unsymmetrical sandwich plates is given. The element formulation is based on generalization of the discrete Kirchhoff theory (DKT) element formulation. The results obtained with the first order approximation of the asymptotic solution presented here are the same as those obtained by means of the modal strain energy (MSE) method. By taking more terms of the asymptotic solution, with successive calculations and use of the Padé approximants method, accuracy can be improved. The finite element computation has been verified by comparison with an analytical exact solution for rectangular plates with simply supported edges. Results for the same plates with clamped edges are also presented.

Regimento Interno da Câmara dos Deputados : Resolução nº 30, de 31 de outubro de 1972

Texto consolidado em 1978 e alterado pelas Resoluções de nº 1, 37, 42, 54/79, 13 e 15/81.

不同形状微管道中的气体流动

不同形状微尺度管道（圆形、六边形、半圆形、不同宽高比的矩形）中的气体流动特性是微机电系统设计最为关心的问题之一．文中利用信息保存（IP）方法和直接模拟Monte Carlo（DSMC）方法进行研究，给出两种方法的计算结果相互符合，并与其它研究者的BGK模型方程计算结果进行了比较．对于微尺度管道中关心的低Mach数流动，IP方法的统计收敛效率明显优于DSMC方法,通过拟合IP和DSMC结果，给出了圆形、六边形、半圆形、不同宽高比的矩形截面情况下无量纲质量流率与等效Knudsen数的关系．

激波风洞中超声速燃烧现象的初步实验研究

介绍了启用激波风洞进行超燃研究所作的改造和得到的初步实验结果。实验除测量常规流场参数和模型表面的动态参数外，主要使用二维实验模型，利用高温气体的自发光和燃烧伴随的发光现象，采用高速摄影技术来观测燃烧现象，记录到高焓流场中叠加燃料喷射和燃烧的流场，观察到自由边界条件下扩散控制的超声速燃烧现象。结果表明激波风洞用于超声速燃烧研究的一些必要的技术问题已基本解决。