利用激光超声无损检测的实验方法,观察记录了瑞利波在具有不同表面微结构厚铝板中的传播过程,研究了表面微结构的声传输特性。对具有不同结构参数的微结构样品进行了分组对比实验,结果表明在一定深度范围内,表面微结构具有明显的分频效应。瑞利波中相对高频的部分被反射,反射信号通带带宽主要受制于微结构的深度,其能量主要受微结构宽度影响。相对低频部分沿表面继续传播,因此表面微结构同时具有一定的低通滤波效应。

The propagation of laser-generated Rayleigh wave on a thick aluminum plate with the surface micro-structure has been investigated by experiment. Experimental results have proved that the surface micro-structure act as a frequency divider for the Rayleigh wave within a certain depth range. The high-frequency part of the Rayleigh wave is reflected. Bandwidth of the reflected pass band is closely related to the depth of the surface micro-structure, and advanced by in-creasing the depth of the micro-structure. The amplitude of the reflected acoustic wave is suppressed by increasing the width of surface micro-structure. The low-frequency part propagates of the Rayleigh wave on the sample surface without disturbance, and the surface micro-structure works as a low-pass filter.

为了实现聚合物微结构件的高效和高精度成型加工，提出基于激光融化的聚合物微结构特征成型新方法，并对其成型工艺进行研究。阐述激光融化成型机制，建立激光融化成型理论模型，理论推导聚合物温度变化与激光参数的相互关系表达式，数值计算和模拟激光辐照下的聚合物基体融化过程，探讨激光融化成型的控制理论与方法。研制试验装置，进行典型聚合物微结构特征激光融化成型试验，测试微结构成型误差，分析模具温度和成型压力等工艺因素对微结构成型效果的影响规律。试验结果表明，试验测试数据与理论计算结果基本相符，获得较好的聚合物微结构特征复制度和成型精度，微结构成型误差小于1μm，说明聚合物微结构特征的激光融化成型方法具有可行性和有效性。

To realize high efficient and precise forming of polymer micro-structured parts, a new process method for polymer micro-structured is presented based on the laser melting, and the corresponding process is studied. The formation mechanism and theoretical model are discussed about laser melting forming of polymer, the relationship between polymer melting temperature and laser parameters is investigated by the method of theoretical analysis, and the polymer melting process is calculated with the way of numerical simulation, and theory and controlling method on melting process are proposed. A small experimental device is developed and the tests for typical polymer micro-structured parts with laser melting forming are carried out. By examining inaccuracy of products, the effects of process parameters on melting forming are investigated, such as mould temperature, process force. The experimental results show that process accuracy and replication of products are got well, the shape

激光全息是制作光子晶体微结构的重要方法，为便于调节参数以提高实验成功率，提出利用CMOS传感器代替传统的记录材料全息干板，将全息干涉形成的微结构实时输入计算机处理。根据多光束干涉原理探讨了实现二维微结构的光束配置和设计原则，结合计算机数值仿真讨论了光束偏振对微结构“原子”形状的影响。进一步设计实验进行验证，结合实时显示技术方便、灵活调节各光束参数，获得了三角晶格和正方晶格两类典型的微结构。实验结果表明，计算机的实时显示技术有助于提高微结构的设计和制作效率。

Laser holography is an important method for fabricating photonic crystal microstructures .In order to facilitate adjusting beam parameters to improve the success rate of experiment , it is proposed to transfer the formed microstructure to a computer for real-time display and processing by using a CMOS sensor .According to the principle of multi-beam interference , the beam configurations and design princi-ples of the realization of 2D microstructures are explored .Combining with numerical simulations , the in-fluence of the beam polarizations on the shapes of the formed microstructure “atom” is also discussed . Further experiments validate the designs .With the help of the convenient real-time display and flexible adjusting of the beam parameters , two kinds of microstructures , i.e., the triangular and square lattices , are obtained .Experimental results show that the real-time computer display technology is helpful to im-prove the efficiency of design and fabrication of m

为研究表面形貌对表面润湿性和抗附着性能的影响,采用激光刻蚀技术制备点阵微结构和仿生贝壳表面网格微结构,将SiO2纳米粒子涂覆在微结构上制备微纳结构。研究表明,Ti6Al4V合金表面经激光刻蚀后由亲水变为超亲水状态。经低表面能修饰后,点阵微结构表面符合Wenzel模式的疏水状态,而网格微结构表面符合Wenzel模式的超疏水状态。在点阵和网格微结构上涂覆SiO2形成微纳结构表面均符合Cassie模式的超疏水状态,且网格结构表面的接触角更大,滚动角更小。浅海挂板实验显示,微生物粘膜附着量由多至少的顺序为:超亲水状态的点阵微结构表面亲水的抛光表面超亲水状态的仿生网格微结构表面符合Cassie模式的超疏水表面。

In order to study the impacts of the surface pattern on its wettability and antifouling performance,la-ser etching technique was used to build dot micro-structure and shell surface like grid micro-structure,and the nano-SiO2 powders were coated on the micro-structures to build micro-nano structures.It was shown that after laser etching,Ti6Al4V alloy surface change from hydrophilic state to super hydrophilic one.Trough low sur-face energy modification,the dot micro structure surface was in hydrophobic state that was in accordance with Wenzel model,while the grid micro structure surface was in super hydrophobic state that was in accordance with Wenzel model.The surfaces with the micro-nano structure formed both by coating the nano-SiO2 on the dot or grid micro-structures were both in super hydrophobic state that were in accordance with Cassie model. The grid structure surfaces have greater contact angles and smaller roll angles.Sea-side exposure test showed that the order of the surfaces

通过构造具有棋盘状微结构的疏水表面,考虑表面张力的影响,利用定常与非定常结合的数值模拟方法,研究了疏水表面在湍流状态下的减阻特性以及微结构内气体封存的效果,其中Re=3000—30000.在低雷诺数下,疏水表面微结构内气体封存状态良好,减阻率最高约为30%;随着雷诺数的增大,压差阻力增大,减阻率有下降趋势.当来流速度过大时,水会大量进入微结构,疏水表面的减阻率变化剧烈,且已经不再减阻.结果表明,表面张力削弱了壁面切应力的影响,使得低雷诺数下微结构内气体能够有效封存,进而减小壁面阻力.

This article studies drag reduction rule and gas restoration and retention of hydrophobic surfaces numerically when taking into consideration the surface tension effect, the microstructure here is chessboard-like and the Reynolds number varies from 3,000 to 30,000. Results show that gas restoration and retention keep well, and a maximum drag reduction rate of approximately 30% has been gained at small Reynolds number(Re<15000). When Re is too large, water will swarm into microstructures, and keeping a good gas-liquid interface becomes difficult. Meanwhile, drag reduction rate remains variable and hydrophobic surfaces do not reduce drag. Through mechanical analysis we find that the influence of shear stress is weakened due to surface tension effect, thus the gas in microstructures can be effectively stored at low flow speed and drag is reduced.