Analysis and simulations of vibrations of a beam with a slider

A model for vibrations of a beam with a slider is derived, analysed and numerically simulated. It describes a viscoelastic beam that is clamped at one end to a vibrating device, while the other end moves between two stops attached to a slider. The contact is described by the normal compliance or by the Signorini conditions. The existence of weak solutions is established using the theory of set-valued pseudomonotone operators. The model is discretized using fourth-order spatial discretization, the solutions are numerically simulated and their results presented. The dynamics of the vibrations are depicted and so are the noise characteristics of the system.     

一类连续模糊动态系统控制方法在Furuta摆中的应用

为了研究Furuta摆在倒立点附近的稳定控制问题，采用基于T-S模糊模型的一类连续模糊动态系统控制方法，首次进行Furuta摆的模糊状态空间建模，并采用模糊切换的思想，设计了Furuta摆在倒立点附近的稳定控制器，进而分析了系统稳定性。与已有的方法相比，该方法的优点是稳定区域大、调节时间短。数字仿真结果验证了方法的有效性。     

用于高频谐振器的PbTiO_3基压电陶瓷

传统的PZT压电陶瓷的相对介电常数较大,一般为1 000以上,用于高频谐振器不易与线路匹配;而PbTiO3基压电陶瓷的相对介电常数较小,一般仅为200左右,对于10 MHz以上频率的谐振器,用PbTiO3基压电陶瓷作为压电振子是最佳的选择。本文主要研究用于高频谐振器的MnO2和Nd2O3改性PbTiO3基压电陶瓷的性质。PbTiO3基压电陶瓷的性质的改善是与此种陶瓷的制备工艺,显微结构和电导机制紧密相关的。     

Investigation into polishing process of CVD diamond films

A new technique used for polishing chemical vapor deposition (CVD) diamond films has been investigated, by which rough polishing of the CVD diamond films can be achieved efficiently. A CVD diamond film is coated with a thin layer of electrically conductive material in advance, and then electro-discharge machining (EDM) is used to machine the coated surface. As a result, peaks on the surface of the diamond film are removed rapidly. During machining, graphitization of diamond enables the EDM process to continue. The single pulse discharge shows that the material of the coated layer evidently affects removal behavior of the CVD diamond films. Compared with the machining of ordinary metal materials, the process of EDM CVD diamond films possesses a quite different characteristic. The removal mechanism of the CVD diamond films is discussed.     

微米／纳米技术及其应用

介绍了当前国际上关于微米、纳米技术及其在微型机械、微型机械电子系统以及在专用集成型仪器等方面的应用。     

具有阻力特性材料的σ_f－σ关系及一种新的阻力曲线测定方法

通过对相变增韧陶瓷及一种可切削玻璃－陶瓷动态疲劳（恒应力速率）试验中高应力速率区断裂应力下降现象的理论分析，发现这种现象与材料的阻力特性（Ｒ－ｃｕｒｖｅ）密切相关。确立的σ_ｆ－σ理论关系能够很好地描述整个应力速率区间内的动态疲劳试验结果。高应力速率区σ_ｆ－σ在双对数坐标下为负斜率直线，直线斜率为（ｍ为阻力曲线ＫＲ＝ｋ（△ａ）~ｍ的指数），断裂主要由材料阻力行为控制；低应力速率区，σ_ｆ－σ在双对数坐标下为正斜率直线，直线斜率为　（ｎ为应力腐蚀指数），断裂主要由材料应力腐蚀行为控制。建立了测定材料阻力特性的一种新方法，分别用这种方法及压痕／弯曲方法对一种可切削玻璃－陶瓷的阻力特性进行了实验测定，两种方法所得结果有很好的一致性。     

Formation and growth mechanism of TiC crystal in TiC_p/Ti composites

1　ＩＮＴＲＯＤＵＣＴＩＯＮＰａｒｔｉｃｌｅｓｒｅｉｎｆｏｒｃｅｄｔｉｔａｎｉｕｍａｌｌｏｙｍａｔｒｉｘｃｏｍｐｏｓｉｔｅｓ(ＴＭＣｐ)ｈａｖｅｗｉｄｅａｐｐｌｉｃａｔｉｏｎｆｉｅｌｄｓｆｏｒｔｈｅｉｒａｔｔｒａｃｔｉｖｅｈｉｇｈｓｐｅｃｉｆｉｃｓｔｒｅｎｇ     

一类非线性MIMO不确定系统的动态输出反馈镇定

考察其标称系统的相对阶大于{1,1,…,1}同时含匹配和非匹配不确定性的MIMO 非线性系统的动态输出反馈镇定问题.文中直接用Lyaunov方法构造一类输出反馈动态补 偿器,该补偿器可以实现对所论非线性不确定系统的动态输出反馈渐近镇定.     

矿业可持续发展理论及应用

在简要回顾我国矿业发展现状及其在环境破坏污染和资源浪费损失的基础上，提出矿业可持纽发展的概念与内涵，论述矿业可持续发展的动态２特征，并就如何实施矿业可持结发展战略进行了思考。