磁存储硬盘单分子层润滑膜的制备、结构与性能

以水为亚相，研究了两种氟代芳氧基磷嗪的π-A曲线，并用LB膜技术在硬盘磁碟表面制备了X-1P和DS-2单分子层膜。用表面反射FTIR、XPS和接触角法表征了单分子层的结构和表面性能。结果表明，X-1P和DS-2单分子层均匀覆盖在磁碟表面并与磁碟发生化学键联作用，经单分子层处理的磁碟表面疏水性明显提高。     

Stable Langmuir-Blodgett film deposition of polyaniline and arachidic acid

An experimental study was carried out to examine the stable Langmuir-Blodgett (LB) film deposition of mixtures of polyaniline (PA) and arachidic acid (AA) at different concentration ratios, with the aim of developing a systematic methodology for the production of quality PA/AA film at the highest deposition speed. The quality of LB film was examined before, during and after the film deposition process. Images of the PA/AA composite materials at air-liquid interface, based on the Brewster angle microscopy, revealed that a 50/50 concentration ratio of PA/AA composite layer produced the best LB film structure. The feasibility of LB film deposition was determined from dynamic contact angles which were measured by a flow visualization technique. The quality of the deposited film was judged by the transfer ratio and the atomic force microscopy images. The effect of pH was also examined, and it was found that the LB film deposition for the PA/AA system could only be carried out in a narrow range of pH. It was found that the deposited LB film of the PA/AA system had a high transfer ratio and improved surface roughness at the deposition speed 30 mm/min. This deposition speed is much higher than those previously reported.     

Evolution of nanoparticles in gold-implanted glass

The interest in metal nanocrystals is focused on their nonlinear optical properties, as they are expected to have a large third-order nonlinear susceptibility. In order to explore the possibility of tuning the size and shape of metal nanocrystals, we implanted gold into fused silica substrate. The implantation energy was 1.1 MeV and doses were of 1, 3, and 6×10¹⁶ ions/cm². All samples were subsequently annealed in air at 1000 and 1100 °C. Grazing incidence small-angle X-ray scattering was used to study the morphology and the distribution of gold nanoparticles formed in the substrate. The clustering process is evident already during the implantation itself. Upon annealing, the number of clusters, as well as their size is increased. The clusters are smaller in the vicinity of the surface, where the effective implant concentration is lower, regardless of the annealing temperature. At the highest annealing temperature the clustering diverges into two distinct size distributions.     

抛光型SLAM系统灵敏度研究

以片式电子材料元器件作为无损检测分析对象,以提高激光扫描声学显微镜(SLAM)系统灵敏度为目标,详细分析了入射声波在抛光型分层介质中的传播规律,建立了抛光型样品自由界面动态波纹振幅数学模型。经综合分析获得了提高系统响应的方法,为进一步改进SLAM提供了理论依据。     

TDA5005全站仪用于11m天线测量

对高精度全站仪用于大中型天线安装测量进行了有益的尝试。坐标测量采用TDA5005全站仪配合测距反射片，导出了测距入射角计算公式，提出了一种反射片加常数测定方法。在数据处理方面，讨论了标志厚度对面型的影响。计算发现，对于圆抛物面天线而言，曲面自由拟合法与CAD面型拟合法是相当的。天线机械调整效果得到了电测结果的验证。     

基于调频广播单站无源系统的定位方法

基于调频广播的单站无源定位系统实际相当于收发分置的双基雷达,以调频广播的发射机作为辐射源,接收雷达位于另一处。在实际的无源雷达系统中,利用数字波束形成技术和比幅测角,可以得到目标方位角。再利用信号到达时间差,可以得到目标和雷达站间的距离信息,从而实现了固定单站对二维运动辐射源的无源定位。最后还给出了定位精度的计算机仿真结果。此定位方法在工程中取得了较好的效果。     

A rapid forming method and simulation on controllable-porosity coating

A new method was introduced to fabricate porous coating and control its porosity by changing spray parameters. Two models were constructed to simulate the deformation of droplet and the deposition process of splats on substrate. Considering the gap-pore, step-pore and shield-pore in the presented models, the influence of spray angle on the porosity of coating was mainly investigated. The simulation and experimental results show that the presented method is suitable for fabricating controllable-porosity coating. The porosity of coating can reach 49%. When the spray angle is lower than 30°, the porosity of coating rapidly increases because of shielding effect. Moreover, powder size and impact velocity also influence the porosity. Besides, a new forming method of graded porous coating was simulated by continuously changing the spray angle.     

一种特殊阵列实现DOA估计的方法

提出了一种基于特殊阵列形式实现DOA估计的方法，在均匀线性阵列（ Uniform Linear Array, ULA）上增加一个阵元，将阵元放在特定的位置，得到一组特殊的阵元组合，打破了均匀线阵中导向矢量的周期性，成功地避免了角度估计模糊．此外，该方法在同等硬件资源的条件下，得到了更多阵元组合，可以获得更高的阵列方位分辨率．提出了一种适用于新阵列结构的矩阵分块空间平滑算法，利用其导向矢量的局部周期性将其数据协方差矩阵分块空间平滑后，重新组合得到修正后的数据协方差矩阵，实现了相干信号源的DOA估计.     

通气超空泡临界通气率的水洞试验分析

形成通气超空泡所需的通气量是设计试验的一个重要参数,适当的通气量才能形成形态可控且减阻的理想超空泡.表征通气量的无量纲参数是通气率,形成超空泡的最小通气率称为临界通气率.在可连续通气水洞中对航行体缩比模型进行了通气超空泡试验,通过改变水洞工作段的来流速度和压力、模型比例和空化器等因素,获得了一系列不同形态的通气超空泡,分析了影响通气超空泡临界通气率的因素.     

Coning motion stability of wrap around fin rockets

Both the asymptotical stability criterion and the bounded stability criterion of the coning motion for wrap around fin(WAF) rockets are proposed through the analy-sis of coning motion equations,which can be easily used to determine the exis-tence of the coning motion during the rocket design. The correctness of the crite-rions is verified by mathematical simulation examples of a WAF rocket with differ-ent setting angles. It is also found that the setting angle of WAF has great effects on the rolling moment and side moment of the rocket.