1.06μm高功率激光反射膜

为提高反射膜的抗激光强度,对ZrO_2-SiO_2多层介质膜的制造工艺进行了深入的研究。已制备出高反射膜和激光输出膜在λ_0=1.064μm处,激光脉宽为1.2ms的单脉冲激光照射下,能承受的能量密度为160J/cm~2;在重复频率为20次/s的激光照射下,能承受的功率密度为1.5kW/cm~2,承受打激光脉冲300万次膜层不损坏,并通过了16kW/cm~2承受激光脉冲7.2万次的超负荷试验。     

Structural design of current-mode biquad filters

This work describes how to generate and design a novel current-mode biquad filter model using tunable multiple-output operational transconductance amplifiers and grounded capacitors (MO-OTA-Cs) for synthesizing both transmission poles and zeros. Transfer functions of low-pass, band-pass, high-pass, notch and all-pass are realized based on the filter model. The theory focuses mainly on establishing a relationship between the cascaded MO-OTA-Cs and the multiple-loop feedback matrix, which makes the structural generation and design formulas. All the filter architectures contain only grounded capacitors, which can absorb parasitic capacitances and require smaller chip areas than floating ones. The simulation results are also presented to confirm the theoretical analysis.     

三防和固封以及混装PCB返修技术

分析了三防漆敷形涂覆和胶粘剂粘固对印制板组装件返修的影响;分析了混装工艺对印制板组件返修的影响;介绍了BGA封装器件返修的一般方法;给出了使用暗红外返修台拆卸元器件时印制板组件的热分布状况;结合实际工作,介绍了采用混装工艺装联并进行了三防固封的航天产品无铅BGA返修的具体实施方法.     

红外隐身技术的现状与发展

综述了红外隐身技术的现状，指明了存在的问题以及发展的方向。     

Optical and Electrical Properties of TixSi1‐xOy Films

Ti_xSi_1xO_y (TSO) thin films are fabricated using plasma‐enhanced atomic layer deposition. The Ti content in the TSO films is controlled by adjusting the sub‐cycle ratio of TiO₂ and SiO₂. The refractive indices of SiO₂ and TiO₂ are 1.4 and 2.4, respectively. Hence, tailoring of the refractivity indices from 1.4 to 2.4 is feasible. The controllability of the refractive index and film thickness enables application of an antireflection coating layer to TSO films for use as a thin film solar cell. The TSO coating layer on an Si wafer dramatically reduces reflectivity compared to a bare Si wafer. In the measurement of the current‐voltage characteristics, a nonlinear coefficient of 13.6 is obtained in the TSO films.     

Simultaneous chromizing-aluminizing coating of austenitic stainless steels

Chromium and aluminum were simultaneously co-deposited by diffusion into austenitic stainless steel substrates, by a single-step, pack-cementation process. The mechanism for the formation of diffusion-coated products on 304 and 316 stainless steels and on Incoloy 800 is discussed. The morphologies of the phases formed at the surface, i.e., an external beta layer and an underlying multiphase interdiffusion zone, are presented. The formation of the brittle, , outer layer was minimized by variations in the pack composition and activator. The coated 304 and 316 steels exhibited excellent scaling resistance upon oxidation in air at 1000°C.     

光纤电场传感器的有限元分析

介绍了具有压电聚合物护套的光纤电场传感器的有限元分析 ,这种光纤电场传感器能响应 10 0 Hz至 5 0 MHz的频率。采用有限元分析可以预知低频段 (轴向非约束 ) 0 .0 19rad/(V· m )的相位偏移和在高频段 (轴向约束 ) 8.2× 10 - 4rad/(V· m)的相位偏移。当频率高于 7MHz时 ,光学响应主要是光纤和聚合物护套组合材料的径向谐振。模拟预测的谐振尖峰和合成理论推算出的谐振尖峰具有很好的一致性     

粉浆法制备平面荧光粉涂层白光LED的技术改进

基于粉浆法制备白光LED能得到厚度可控的荧光粉层,改善了白光LED的均匀性.由于芯片长时间工作时表面的发热以及回流焊时的瞬间高温环境,聚乙烯醇(PVA)感光胶的颜色容易发生改变,影响了白光LED光效的稳定性.本文采用等离子体去胶,实验结果表明,通过该方法能有效去除感光胶,处理后的LED不会因为长时间工作荧光粉表面涂层的...     

玻璃基板激光选区镀膜研究

针对传统制备导电薄膜工艺复杂、成本高,且在激光直写导电膜中存在所加入的辅料造成杂质污染以及膜的厚度和粗糙度难以降低等问题,本文采用玻璃衬底激光制备Zn/Al混合粉末生成导电薄膜,实现了无粘结剂和辅料的薄膜生成,研究了工艺参数调节对膜的生成质量的影响。结果表明,过低或过高的激光扫描速度都会使表面粗糙度增加,扫描速度过慢时...