中波红外制冷型光学系统消热差设计

对比了典型消热差方法的优劣,探讨光学被动式消热差的基本理论。在此基础上,根据系统要求的温度范围 60℃～90℃,在常温初始结构的基础上,利用Zemax软件的多重结构和自动热分析功能增加其他温度结构,运用光学被动式消热差方法进行热平衡和像差平衡,最终设计出一套中波制冷型消热差光学系统。光学设计时以探测器冷阑作为系统孔径光阑,实现了100%冷阑匹配。结构材料使用铝,光学材料为硅、锗和硒化锌,将它们组合消热差。系统在-60℃～90℃温度范围内,最大离焦量小于1倍焦深,空间分辨率17 lp/mm处,光学调制传递函数(MTF)值均大于0.74,接近衍射极限,点列图弥散斑均未超出单像元尺寸范围。     

Removal of NO Molecules by a Novel Atmospheric Pressure Plasma Apparatus

A novel atmospheric pressure plasma apparatus （APPA） is designed with a liquid electrode, and its discharging characteristics are studied. Relatively uniform and intense discharge can be realized in the APPA system. An experimental study on removal of NO molecules is carried out by using the APPA, and more than 95.5% of NO is decomposed when the NO initial concentration is lower than 400ppm. Removal of NO efficiency increases rapidly with the increasing discharge power. Compared with the absence of O2, more NO2 is generated with the increase of O2 concentration. However, most of the NO molecules are decomposed to N2 and O2 directly, when O2 concentration changes from 0 to 1.1 vol%.     

拓宽思路找方法，准确与否靠检验——高考数学填空题答题思路与方法初探

<正>高考数学填空题通常是将一个数学真命题写成其中缺少一些语句的形式,要求考生将缺少的语句填写在指定的空位上,使之成为一个完整而正确的数学命题.根据填空题的内容可将其分为两种题型：一种是定量型的,要求考生填写数值或数量关系,如方程、不等式的解,函数的定义域、值域、周期,某参变量的值或变化范围,等等;另一种是定性型的,要求填写具有某种性质的数学对象或数学对象的某种性质等.