偏压及测试环境对离子束DLC膜摩擦学行为的影响

采用线性阳极层离子束技术制备了类金刚石薄膜(DLC膜),研究了不同衬底负偏压和测试环境对DLC薄膜摩擦学性能的影响.结果表明:在-50V偏压下,薄膜硬度和弹性模量最大,这主要与薄膜中高的sp³含量相关;衬底负偏压对薄膜在室温大气条件下的摩擦学性能影响不显著,薄膜总体呈现较低的摩擦系数和磨损率,显示出优异的抗磨损性能;线性离子束制备的含氢DLC薄膜的摩擦学行为受湿度及环境气氛影响较大,归因于环境中的氧气和水分造成的摩擦化学反应.     

实散组合桩承载原理及应用

本文提出了实散组合桩概念,即一根桩由上下两段组成,上段是实体桩,下段是散体桩。这样就克服了散体桩通常桩头承载能力低的缺陷。本文对实散组合桩的受力概念进行了分析研究,给出了其承载力、沉降、临界桩长等计算方法和公式。最后介绍了首次工程实例。     

精密仪器设备半挂运输列车的振动模态分析

研究了具有牵引悬置装置的精密仪器设备半挂运输列车的振动问题,建立了14 自由度的动力学模型并进行振动模态分析, 在此基础上,计算了某典型半挂运输列车在有阻尼和无阻尼情况下的固有频率和振型.     

无刷直流力矩电机系统的自适应扰动力矩补偿研究

陀螺漂移测试转台无刷直流力矩电机系统中存在波动力矩和负载力矩振动，这严重地影响了转台速率平稳度。为提高转台速率状态位置跟踪精度，设计了一种自适应补偿方法。该方法包含一个参自适应律和等效PID控制律，它利用前馈补偿原理，来估计电机中未知参数以及波动力矩和负载力矩参数并给与补偿。该自适应补偿方法保证了闭环系统全局稳定性和对期望位置信号的渐进跟踪。仿真结果证明：该方法有效地提高了转台速率状态跟踪精度。     

Kinetics of Catalysis-Driven Aggregation Processes with Sequential Input of Catalyst

We investigate the kinetic behavior of a two-species catalysis-driven aggregation model, in which coagulation of species A occurs only with the help of species B. We suppose the monomers of species B are stable and cannot selfcoagulate in reaction processes. Meanwhile, the monomers are continuously injected into the system. The model with a constant rate kernel is investigated by means of the mean-field rate equation. We show that the Mneties of the system depends crucially on the details of the input term. The injection rate of species B is assumed to take the given time- dependent form K（t） -t^λ, and the sealing solution of the duster size distribution is then investigated analytically. It is found that the cluster size distribution can satisfy the conventional or modified scaling form in most cases.     

General Solutions of Reflection Equations for Bariev Model

The integrable general open-boundary conditions for the one-dimensional Bariev chain are considered. All kinds of solutions to the reflection equation （RE） and its dual are obtained.     

谱体积方法单元分割与问题单元标记方法的改进研究

谱体积方法是一种本质上解决网格依赖性的高精度CFD计算方法,本文研究了二维Euler方程的谱体积方法,提出一种基于切比雪夫多项式的单元分割方法,建立了基于WENO的变量限制器方法,并发展了结合谱体积和控制体的问题单元标记方法.采用15°超声速压缩拐角和NACA0012跨声速流动两个典型算例进行验证,结果表明,该分区方法具有更好的计算精度,标记方法可有效识别不连续区域,在较少的网格下即可获得与密网格传统有限体积法相当的计算精度.     

Contact vibration analysis of the functionally graded material coated half-space under a rigid spherical punch

This paper studies the contact vibration problem of an elastic half-space coated with functionally graded materials (FGMs) subject to a rigid spherical punch. A static force superimposing a dynamic time-harmonic force acts on the rigid spherical punch. Firstly, we give the static contact problem of FGMs by a least-square fitting approach. Next, the dynamic contact pressure is solved by employing the perturbation method. Lastly, the dynamic contact stiffness with different dynamic contact displacement conditions is derived for the FGM coated half-space. The effects of the gradient index, coating thickness, internal friction, and punch radius on the dynamic contact stiffness factor are discussed in detail.     

铌酸锂衬底上磁控溅射ITO薄膜及其光电性质研究

在铌酸锂(LN)晶体衬底上磁控溅射铟锡氧化物(ITO)薄膜,研究了射频磁控溅射制备ITO/LN薄膜的最佳工艺.采用原子力显微镜(AFM)和X射线衍射(XRD)分析了透明导电ITO膜的制备工艺参数对薄膜表面形貌和晶体结构的影响,同时应用四探针电阻率测量和紫外可见光谱测量技术对所研制的ITO/LN膜的光电性质进行了研究.结果表明,衬底温度为320℃,溅射时间50 min时制备的ITO/LN薄膜具有最佳光电性质,在该条件制备出薄膜的电阻率为3.41×10-4Ω·cm,ITO/LN平均可见光透光率可达74.38;,平均透光率比LN衬底提高了1.1;.应用该溅射条件制备了泰伯效应位相阵列器,其近场衍射成像的相对光强可达0.67.