回转机械系统动态分析方法研究

本文利用试验模态分析理论,为回转机械系统通过扭转激振方法对其进行动态分析提出了一实验方案,并以调速器为实验对象,根据此方案设计并研制了一台试验装置,使试验模态分析理论在回转机械的动态分析中得到了应用。通过对调速器的动态分析,证明该方案可行。此法对各种以转动为输入量的机械系统具有普遍意义。     

Direct observation of the clockwise light-driven rotation of F<Subscript>0</Subscript>F<Subscript>1</Subscript>-ATP synthase complex

The purified thermophilic bacterium PS3 F₁ β _10×His-tag is inserted into the F_oF₁-ATP synthases of chro-matophores isolated from photosynthetic bacteria Rhodo-spirillum rubrum. The studies of biochemical properties of the hybrid chromatophores show that they have both protons-driving capability and photophosphorylation. The fluorescent actin filaments, as a marker of its orientation by video-microscopic experiment, are connected via Maleimido-C₃-NTA to the reconstituted β_10×His-tag of F_oF₁-ATP synthases. The clockwise rotation of F_oF₁-ATP synthases driven by light is observed directly when viewed from the F_o side to F₁. This system should be valuable for further studying the coupling property of F_oF₁-ATP synthase.     

Mechanism and estimation of negative entropy flow in terrestrial system

The origin, existence and evolution of life on the earth depend on the negative entropy flow in the terrestrial system (TS). In this paper, we investigate the mechanisms of different negative entropy flows caused by the vertical heat transfer of water phase transition and the gravitational field effect, and the vertical atmospheric heat transfer and the gravitational field effect, under the influences of the sun's radiation, the photosynthesis of the plants, and the earth's rotation. The magnitude orders and the mechanisms of the abovementioned negative entropy flow are also discussed.     

A New Method on Resolving the Rotation in the Plane of Skew Bridges

0IntroductionSkhiegwh wbariyd.g eHso awreev eorf t,etnhe a pinplhieerden otn di smaudnviacniptaalge r ooafd s kaenwdbridges ,i .e.the rotation in the plane always exists . Alongwiththe displacement growth,the girder will rotate and evencause cracks ,the e…     

Head rotation and sound image localization in the median plane

The effect of head rotation on median plane sound source (or image) localization is studied. It is suggested that, at low frequency, the change of interaural time difference (ITD) caused by head rotation supplies information for determining sound source direction in the median plane. Based on the suggestion, the summed sound image Ioealization equations for multiple loudspeakers arranged in the median plane are derived. Especially, for a pair of loudspeakers arranged front-back symmetrically in the median plane, the localization equations are similar to that of stereophonic sound in horizontal plane. A sound image localization experiment was carried out to prove the theoretical analysis. The results of this paper are not only available to virtual spatial auditory, but also supply a quantitative validation of the hypothesis that head rotation is a cue for sound source localization in the median plane at low frequency.     

圆柱体相对转动动力学方程的速度解

针对圆柱体任意两个横截面间的相对转动动力学方程，运用解耦方法获得方程的解析解，由于方程的特殊性，利用变量代换求得两次积分解。从而得到了圆柱体相对转动动力学方程的积分形式表达式。根据工程应用，给出了冲击性和周期性两类典型载荷作用下的解析解。     

小角度测量的光学方法及应用

光学测角法是高精度动态角度测量的一种有效的解决途径．对目前发展较快的几种小角度测量的光学方法——圆光栅测角法、光学内反射小角度测量法和激光干涉测角法进行了介绍．对光学测角法在舰船甲板变形测量中的应用进行了详细的阐述．     

加强三维转动意识训练提高人体运动机能

人体和刚体一样在空间可作三维运动．三维运动的物体有3个相互垂直的运动轴,有6个自由度．沿3个轴可作三个方向的直线运动,也可绕三轴转动或旋转．但在人体下支撑时三个轴直线方向的运动受到约束,可作三轴的转动或旋转,称为人体三维转动．三维转动是人体的运动技能,是人体运动时气血循环体液代谢的基础,也是人体一种运动规律．人体运动通过三维转动调动大群肌肉产生动力,又以转动的形式传递作功．体育运动时由于高速度大负荷约束了人体平时的运动条件,在约束力作用下人体三维转动必须经过训练才能完成,三维转动训练可提高人体运动机能．     

Hilbert空间上的保测线性算子

设Ｔ是复的可分Ｈｉｌｂｅｒｔ空间Ｈ上的有界性算子,那么关于Ｔ不变的有强二阶矩的Ｂｏｒｅｌ概率测度的支集全体张成的闭线性子空间等于Ｔ的旋转特征向量分体张成的闭线性子空间。     

无自转活齿双摆线行星减速器

无自转活齿双摆线行星减速器是一种新型的减速器，与摆线针轮行星减速器相比，本减速器可获得更小的传动比，偶数及小数传动比，并且转臂轴承转速低，文中给出了传动计算公式及正常传动结构条件，为设计提供了理论依据。