网际组态软件Advantech WebAccesss报表设计及应用

应用网际组态软件Advantech WebAccesss可快速完成值班报表、日报表、月报表的组态.以冶金过程控制仿真系统为例,完成其温度过程控制的报表组态,报表也可通过Email自动发送给用户.     

基于多种小波分解方法综合判决的低误报率分布式光纤围栏入侵监测系统

针对相位敏感光时域反射计型分布式光纤围栏入侵监测系统对外界干扰敏感、误报率高的问题进行了深入研究,比较了多种小波提取入侵信号突变特征方法,并提出一种基于多个小波分解结果进行综合判决来降低分布式光纤围栏误报率的方法.实验结果表明,多种小波分解可以分别提取不同层次的突变细节信息,为综合决策提供更完备的信息和条件,比单一判决...     

ANALYSIS OF LASING PERFORMANCES OF Yb3+-DOPED YAG, FAP, KYW CRYSTALS

The Yb³⁺ laser emitting at a 1.03μm wavelength has been evoking strong interest recently due to its advantages of long fluorescence lifetime, broad absorption band and the fact that it never shows concentration quenching. On the other hand, as a laser of three-level system it has, in general, a relatively high threshold power, which makes it important to seek some suitable host crystals to reduce this. Here, we present a comparison of the lasing performances of Yb³⁺-doped YAG [Y₃Al₅O₁₂], FAP [Ca₅(PO₄)₃F] and KYW [KY(WO₄)₂] crystals, including threshold power and slope efficiency, with those of the Nd:YAG laser based on the threshold formula of three-and four-level systems deduced by the authors. The results show that the Yb³⁺ laser can output a power larger than the Nd:YAG laser does in the case of comparably higher pumping power, if the length of the lasing rod and the concentration of the active ions satisfy some conditions. The theoretical results are also close to the experimental results reported.     

卤化铅调整Tm3+/Yb3+共掺碲酸盐玻璃上转换发光研究

研究了卤化铅调整Tm³⁺/Yb³⁺共掺碲酸盐玻璃的热稳定性能、Raman 光谱和上转 换发光光谱，分析了Tm³⁺/Yb³⁺共掺氧卤碲酸盐玻璃的上转换发光 机理.结果发 现：混合卤化铅调整Tm³⁺/Yb³⁺共掺碲酸盐玻璃具有好的热稳定性 能、低的声 子能量、强的上转换蓝光.这表明混合卤化铅调整Tm³⁺/Yb³⁺共掺碲 酸盐玻璃是一种上转换蓝光激光器的潜在基质材料. 关键词： 氧卤碲酸盐玻璃 上转换光谱 发光机理 上转换蓝光激光器     

卤化铅调整Tm3+/Yb3+共掺碲酸盐玻璃上转换发光研究

研究了卤化铅调整Tm3+/Yb3+共掺碲酸盐玻璃的热稳定性能、Raman光谱和上转换发光光谱,分析了Tm3+/Yb3+共掺氧卤碲酸盐玻璃的上转换发光机理.结果发现:混合卤化铅调整Tm3+/Yb3+共掺碲酸盐玻璃具有好的热稳定性能、低的声子能量、强的上转换蓝光.这表明混合卤化铅调整Tm3+/Yb3+共掺碲酸盐玻璃是一种上转换蓝光激光器的潜在基质材料.     

锑化铟晶片高温加速贮存性能变化研究

锑化铟晶片在存放以及使用过程中的性能稳定性是影响制备的探测器性能的重要因素之一。为了探究锑化铟晶片在长时间放置情况下的性能变化情况,对锑化铟晶片进行高温加速贮存试验,并在试验过程中对晶片几何参数、表面粗糙度、电学参数、位错缺陷等几个重要性能参数进行跟踪检测。结果表明,在高温加速试验条件下,除晶片外形发生轻微变化以外,其他性能基本不发生变化,晶片能够长期保存。     

Nitrogen Dioxide Sensing Properties and Mechanism of Copper Phthalocyanine Film

Copper phthalocyanine film, a p-type organic semiconductor, is synthesized by vacuum sublimation and its surface morphology is characterized by SEM. A silicon-based copper phthalocyanine film gas sensor for NO2 detection is fabricated by MEMS technology. The results show that the resistance and sensitivity of copper phthalocyanine film decrease obviously as the NO2 concentration increases from Oppm to lOOppm. However, the sensitivity nearly keeps a constant of O. 158 between 30 ppm and 70 ppm. The best working temperature of the gas sensor is 90℃ for NO2 gas concentrations of lOppm, 20ppm and 30ppm, which is much lower than that of general metal oxide gas sensor.     

流道缩扩比对1+1/2对转涡轮高压动叶性能影响的研究

本文以1+1/2对转涡轮为背景,采用理论分析与数值模拟相结合的方法对某1+1/2对转涡轮高压动叶进行了优化设计.研究结果表明,流道缩扩比对高出口马赫数涡轮叶栅性能有重要影响,合理的流道缩扩比能减弱甚至消除尾缘内伸波,从而提升叶栅的性能.文中综合考虑了叶栅流道周向以及径向两个方向的扩张因素后选择了叶栅流道缩扩比,进行1+...     

基于LPC1114的智能节能LED台灯控制器设计

本设计采用NXP基于ARM Cortex M0的MCU--LPC1114作为核心控制器,利用其丰富的片内外设,通过环境光线传感器和超声波测距传感器实时采集环境光线强度和用户到LED台灯的使用距离,并与通过用户按键设置的LED台灯使用距离和亮度进行对比,从而调节LPC1114的PWM输出占空比,驱动LED台灯驱动器,在保证LED台灯使用视野亮度恒定的情况下,实现人走灯灭和根据环境光线强度智能调节LED台灯亮度两大功能,实现智能节能效果。本设计是一个高效、低成本且有良好用户体验的解决方案。