在适当的坩埚旋转速度和生长速度下,采用新型凝固工艺--离心定向凝固,可获得具有较理想的分层且定向生长的过共晶Bi-Mn合金自生复合材料;其显微结构特征是粗纤维状的MnBi化合物均布在断面内层的纯Bi基体中,外层则主要是Bi基体.着重对离心定向凝固工艺下的分层生长机制加以详细分析,同时对影响分层的多种因素进行论述.

对比研究了SiC微粉和纳米Al2O3粉末的液相分散效果及其与不同分散剂及介质、PH值的关系,优化了制备低固相含量稳定悬浮液的最佳工艺参数,其研究结果对纳米复合陶瓷材料的制备有一定的指导意义.

The limitation of one-stage isolation system at high frequencies makes people study more complicated structure to improve the isolation effect. Insert ing the medium mass between the vibration source and the base is an effective wa y, which can be easily applied in engineering. The mechanism of power flow tr ansmissi on in this structure is studied by presenting the theoretical model, deriving th e exp ressions of the power flow spectra and plotting its curve. The studies show that the isolation effect at high frequencies can be improved by inserting the inter mediate mass. The system should adopt symmetrical structure from the viewpoint o f vibration control. Furthermore, the medium mass and the base's stiffness can affect the positions of their resonance respectively, which can be used to acqui re wide isolation frequencies range.

纳米复合陶瓷材料可以极大地提高抗弯强度和断裂韧性.综述了目前相关的增韧补强机理的研究情况,主要包括基体晶粒的细化及由沿晶断裂向穿晶断裂模式的转变,热处理对微裂纹的愈合作用;指出了研究中尚需解决的问题.

将有限元技术与模态分析理论相结合,在有限元软件的基础上研制了一套用于风力机塔架结构的动态分析程序系统。讨论了模型建立、载荷施加、边界条件和模态参数的计算,并给出了应用实例及结果分析。

Under the guidance of the "theory of generalized mapping"，this paper investigates the potential of creativity and the principal methodologies of modular fixture design automation. It is pointed out that the decomposed granularity space of generalized field is the key element of product creative design. So the fixturing faces of the workpiece is firstly analyzed, and the functional requirement is extracted. The set of the function requirements fixture is constituted.The automatic Function-Form Mapping is researched in detail. The set of the function requirements of modular fixture is constituted. The muti-schemetic reconstitution of the conceptual fixture structure is explored, where the potential of creativity is exemplified.

从轻骑集团某型号发动机总成中的异响入手,研究了初级齿轮传动的动态性能,分析了初级齿轮传动动态性能对发动机总成异响的影响规律;通过改变齿轮传动的结构参数和进行齿轮齿廓修形,提高了初级齿轮传动的动态性能,降低了发动机异响率,提高了发动机质量,增强了轻骑摩托车的市场竞争力.

根据齿轮传动可靠性与优化设计的相关性,建立起双级行星齿轮传动在合理可靠性条件下的优化设计数模.在寻求多目标优化全局最优解过程中, 为减少全局寻优的盲目性,解决统一权法加权处理的困难,应用了模糊集合概念和贴近度算法,从而克服了原设计方案可靠性方面的缺陷,使设计参数更加先进、合理、准确.

A new researched drill of machining super hard and brittle materials, which can combines ultrasonic vibrating with grinding of diamond grits, is introduced.,The drilling mechanism of this drill is given, and the methods of designing and manufacturing are given too. The result of experiment shows that the drill is an ideal tool for machining ceramics, gems and marbles, etc.

本文介绍了一种新研制的工具锤装柄机的工作原理及组成结构 ,阐述了液压系统的设计要点 ,绘制了液压系统的工作原理图 ,列举了该工具锤装柄机的应用实例。该装柄机较好地克服了手工装柄造成的装柄不正及锤柄端部变形的问题

描述了以小子样机械系统寿命序列为代表的时间序列系统的浑沌特性,阐述了灰色关联分析和灰色模型在机械产品可靠性分析与预测中可开拓贫信息的工程背景,论述了GM和BP预测方法在机械系统寿命预测时各自的特长和缺陷,以及作者创立的GM+BP预测方法具有扬长避短、优势互补的优良特性,同时提出BP神经网络的分形问题和短序列BP网络的构造过程,并以3个工程实例进一步验证了灰色关联分析和GM+BP方法的优良特性.本文旨在应用浑沌、分形理论对重大机械产品可靠性分析与预测的小样本开发有所突破.