我国机电产品出口跃居世界第三紫外纳米压印模板表面修饰工艺研究

研究紫外纳米压印技术的模板表面修饰工艺,对经过表面修饰的模板与未经修饰的模板得到的不同压印结果,通过大量实验进行对比分析,验证模板表面修饰工艺是有效控制压印结果,确保压印复型精度的关键.     

支持亚波长结构光刻的紫外干涉光学头

设计了351 nm紫外光条件下支持亚波长结构干涉光刻的光学透镜组,数值孔径达到0.46,支持双光束最大干涉角度55°,该光学头理论上能光刻的最小结构周期为400 nm.研制了采用熔石英位相光栅作为分束元件的干涉光学头,在351 nm波长下,光刻了周期为450 nm的点阵结构,得到了尺寸约200 nm的凸点结构,实验结果表明,该光学头具有支持亚波长周期结构光刻的功能,是一种亚波长结构器件制造的重要技术手段.     

纳米压印技术的研究

介绍了纳米压印技术的原理,讨论了纳米压印中材料的制备及热压印、紫外压印、微接触印刷等3种常用的压印工艺及其关键技术,提出纳米压印技术的研究方向和面临的挑战。     

二维抗反射亚波长周期结构光栅的设计分析

利用严格耦合波理论(RCWA)和等效介质理论(EMT)研究了二维抗反射亚波长周期结构光栅的设计问题.以立方体和柱状单台阶网格光栅和金字塔形及圆锥形多台阶光栅为例,主要研究了占空比和表面面形对反射率的影响.通过计算发现,当光栅周期足够小的时候,光栅面形对反射率没有影响,同时占空比严重影响着光栅的特性,这对设计制造抗反射光栅非常有用.同时也研究了等效介质理论的适用性.     

紫外臭氧垂直探测仪波长精度分析与波长定标新方法的研究

对紫外臭氧垂直探测仪波长扫描机构中的凸轮廓线、摆杆长度和齿轮组传动等误差,及受温度因素对波长精度影响进行分析,得出理论波长精度为±0.035nm。地面采用C-T型1.5m单色仪和标准氘灯相结合的新方法,对大气臭氧吸收12条波长及160～400nm光谱进行波长定标,分析定标的不确定度为±0.026nm。通过在轨波长测试的结果表明:仪器的波长精度为±0.023nm,与理论分析值相符,验证了波长精度的理论分析、定标方法和不确定度计算的正确性。     

ZW—2型多波长紫外吸收检测器的研制

多波长紫外吸收检测器具有结构简单、灵敏度高、线性范围宽、基线稳定、造价低廉等一系列优点，具有良好的应用前景。本文对该仪器的整机原理、电路、光路及主要部件的设计作了较详尽的叙述。     

涂胶机的设计及涂胶工艺研究

本文对涂胶机的设计以及涂胶机设计与涂胶工艺的关系进行了理论分析和实践研究，为其他表面装饰机械的设计提供了经验。     

基于聚合物模板的变种压印工艺研究

纳米尺度的结构成形是纳米技术和纳米制造中的核心工艺之一。纳米压印技术以高分辨率、高效率、低成本的独特优势已经成为具有广泛应用前景的纳米成形工艺方法。压印模板是压印技术的核心要素,压印模板的特性也决定了压印工艺的技术路线和特点。因此,研究和开发新型的压印模板及其相应的新压印工艺是压印技术研究方向的主要课题。     

亚波长周期结构与多层增透膜反射特性的比较

为解决光学系统中普遍存在的菲涅耳反射问题,利用严格耦合波法设计、分析了一种三维轮廓亚波长结构,然后把计算结果同多层反射膜的增透特性进行了比较,结果表明该结构在很宽的波段上尤其是远红外波段上的抗反射特性要远远好于多层膜,其反射率基本上能控制在0.2%以内;并且这种结构反射率的变化随入射光波入射角的偏离在40°以内能保持在1%以下,而多层膜只能在30°以内勉强做到这一点。     

基于遗传算法的汽车涂胶工艺视觉检测标定技术研究

汽车涂胶工艺是汽车制造过程中的一个重要环节,它对汽车有防腐、防震、隔音和密封等作用。为了提高汽车零部件涂胶质量控制需求,阐述了一种基于遗传算法的汽车涂胶工艺视觉在线检测的标定技术,实现汽车涂胶过程的自动化,在实际应用中取得良好的标定效果,降低了劳动力资源成本,提高了汽车涂胶的生产效率和汽车涂胶的智能化水平。     

飞秒激光抛光CVD金刚石涂层表面

为了实现降低金刚石涂层粗糙度的目的,本文研究了飞秒激光功率,重复频率以及扫描速度对金刚石涂层表面粗糙度的影响,试验之后利用白光干涉仪检测抛光区域形貌以及粗糙度。试验结果表明：粗糙度随着功率的降低而减小,当功率降至100 mw以下时抛光后的粗糙度会随着功率的降低而略微的提高;重复频率对抛光后的粗糙度无显著影响;粗糙度随扫描速度的增大而减小,当扫描速度增加到1.6 mm/s之后,粗糙度会出现略微的升高。在功率100 mw,重复频率1 KHz,扫描速度1.6 mm/s的条件下,得到的粗糙度最低,约为0.14 μm,局部区域粗糙度可降至100 nm以下,并且抛光的区域相对于未抛光区域更具有致密性,基本上满足金刚石涂层低摩擦表面的要求。     

Adhesion and friction studies of a nano-textured surface produced by spin coating of colloidal silica nanoparticle solution

This paper presents the results of adhesion and friction studies on a nano-textured surface. The nano-textures were produced by spin coating colloidal silica nanoparticle solution on a flat silicon substrate. Surface morphology was characterized by environmental scanning electron microscopy (ESEM) and scanning probe microscopy (SPM). Adhesion and friction studies were conducted using a TriboIndenter employing diamond tips with 5 μm and 100 μm nominal radii of curvature. The results show that the adhesion forces and coefficients of friction of the nano-textured surface measured by the 100 μm tip were reduced up to 98 and 88%, respectively, compared to those of a baseline silicon oxide film surface.     

长波红外广角地平仪镜头的光学设计

介绍适用于非致冷凝视式焦平面阵列的长波红外(LWIR)广角地平仪镜头的光学设计.其工作波长范围10～16μm,全视场角为135°.采用"负-正-正"型式的反远距像方远心光路镜头结构,仅有三块非球面锗透镜构成.能够很好地解决广角镜头轴外像差校正和像面照度均匀性问题.此镜头结构简单、体积很小、后工作距离大,成像质量接近于衍射极限,在20lp/mm空间频率处的调制传递函数值超过0.6,像高与视场角关系偏离线性的相对误差不超过15%.文中还分析了此镜头的加工和装调公差.     

光学镀膜近红外膜厚监控的信号压噪

在光学真空镀膜膜厚监控过程中,近红外波段信号弱、外界干扰大、信噪比低,难于检测监控。运用相干检测、锁相放大原理,在光学真空镀膜机可见光波段监控系统的基础上,自行研制锁相放大器和改装近红外探头,成功地实现了近红外信号的压噪、放大、滤波和检测监控。     

Investigation of FE model size definition for surface coating application

An efficient prediction mechanical performance of coating structures has been a constant concern since the dawn of surface engineering. However, predictive models presented by initial research are normally based on traditional solid mechanics, and thus cannot predict coating performance accurately. Also, the high computational costs that originate from the exclusive structure of surface coating systems (a big difference in the order of coating and substrate) are not well addressed by these models. To fill the needs for accurate prediction and low computational costs, a multi-axial continuum damage mechanics (CDM)-based constitutive model is introduced for the investigation of the load bearing capacity and fracture properties of coatings. Material parameters within the proposed constitutive model are determined for a typical coating (TiN) and substrate (Cu) system. An efficient numerical subroutine is developed to implement the determined constitutive model into the commercial FE solver, ABAQUS, through the user-defined subroutine, VUMAT. By changing the geometrical sizes of FE models, a series of computations are carried out to investigate (1) loading features, (2) stress distributions, and (3) failure features of the coating system. The results show that there is a critical displacement corresponding to each FE model size, and only if the applied normal loading displacement is smaller than the critical displacement, a reasonable prediction can be achieved. Finally, a 3D map of the critical displacement is generated to provide guidance for users to determine an FE model with suitable geometrical size for surface coating simulations. This paper presents an effective modelling approach for the prediction of mechanical performance of surface coatings.     

A fuzzy logic predictive model for better surface roughness of Ti–TiN coating on AL7075-T6 alloy for longer fretting fatigue life

In this study, the fretting fatigue resistance of AL7075-T6 alloy is investigated using surface treatment Ti–TiN multilayer coating by physical vapor deposition (PVD) magnetron sputtering technique. A fuzzy logic model was established to forecast the surface roughness of Ti–TiN coating on AL7075-T6 with respect to changes in the input process parameters of DC power, temperature, DC bias voltage, and nitrogen flow rate. The results indicate an agreement between the fuzzy model and experimental results with 95.349% accuracy. The fretting fatigue lives of Ti–TiN-coated specimens with the lowest surface roughness resulting from fuzzy logic were enhanced by 18% at low cyclic fatigue, while at high cyclic fatigue the result was reversed.     

Effect of the specimen geometry on wear - combination of polyacetal (POM) and carbon steel for machine structures

Engineering plastics which have been shown to have good mechanical properties are now frequently used as materials for various machine elements. Engineering plastics are combined with other engineering plastics and metallic materials for machine construction. These machine elements are fabricated with contact surface forms, such as convex, concave, and plane surfaces. Therefore, when designing machines with a combination of materials containing engineering plastics, it is useful to know the wear and friction characteristics for various contact surface forms. In the present research, polyacetal (POM), an engineering plastic, and carbon steel, a metal often used for machine structures, were chosen as materials to study wear and friction. Wear tests were performed in the combination of a convex surface and a plane, and in the combination of a plane and a plane. As a result, some features of the wear and friction characteristic are clarified. (1) The worn mass when the flat specimen made of POM is rubbed by the POM pin specimen is larger than when with the pin specimen made of carbon steel. (2) When the flat specimen made of POM is rubbed by the POM or the carbon steel pin specimen, the same grade of wear is observed regardless of the pin specimen material. (3) The worn length of the steel spherical pin specimen on the steel flat specimen becomes close to the initial radius of the curvature of the pin specimen when the sliding distance is large. The initial condition of the spherical tip pin specimen on the flat specimen evolves toward a condition of the flat tip pin specimen on the flat specimen. So, the comparison between the two geometries is non-relevant. Such problem did not occur in POM pin specimen.     

Platinum/iridium/carbon: a high-resolution shadowing material for TEM,STM and SEM of biological macromolecular structures

Thin Pt/Ir/C coating films (1.5 nm) show a fine granularity and provide a high structural resolution in the transmission electron microscope (TEM) when applied to freeze-dried biological macromolecules. They keep their structure when exposed to atmospheric conditions, without the need of an additional stabilizing carbon layer, in contrast to conventional high-resolution shadowing materials such as Ta/W and Pt/C. However, the correct ratio of the components has turned out to be crucial. When evaporating Pt/Ir/C from the source electrode in an electron-beam-heated evaporator, the ratio of the three elements changes progressively, and, consequently, the properties of such films depend strongly on the mass that has been pre-evaporated. In this paper we present a quantitative analysis of the composition of Pt/Ir/C films by wavelength-dispersive X-ray analysis (WDX) undertaken in association with TEM experiments. We applied Pt/Ir/C shadowing to two regular biological test specimens, the phage T4 type III polyhead and the HPI-layer of Deinococcus radiodurans. It turns out that Pt/Ir/C films containing at least 25% C are three-dimensionally stable on the freeze-dried macromolecular samples. By the dramatically improved resolution power of the latest scanning electron microscopes (SEM) and the invention of the scanning tunnelling microscope (STM), two new surface-sensitive tools for the investigation of biological macromolecular structures became available. The Pt/Ir/C coating has proved to be well suited for STM and SEM imaging of freeze-dried biological structures because of its good electrical conductivity and its direct three-dimensional stability. We compare STM, SEM and TEM images of freeze-dried and Pt/Ir/C-coated polyheads.