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为从原理上阐述同质材料反射系统的温度特性,并为光学系统设计提供依据。以热变形特征及其计算方法为基础,以光学系统焦点为研究对象,依次介绍单反射镜、共轴多反、离轴反射系统的温度特性,并建立了相应热差模型。仿真结果表明,离轴三反系统后焦距随温度的变化情况与对应镜筒的热变形量完全一致,其在较大温差范围内具有良好的成像质量。由温度变化引起的热离焦可被镜筒补偿,验证了理论模型的正确性,得出在均匀温度场条件下同质材料反射系统无热差的结论。因此,当光学系统尤其是热差效应明显的红外系统采用同质材料反射系统时具有良好的温度适应性。 相似文献
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A new process of magnetorheological figuring(MRF) based on the deliquescence theory is proposed to finish KDP crystals.A novel,non-aqueous,and abrasive-free magnetorheological(MR) fluid is explored,and polishing experiments are performed on a self-developed MRF machine.The removal mechanism is reckoned to be the result of a combination of dominant chemical etching and accessorial mechanical drag.The results indicate that the surface roughness of I plate KDP of 80 × 80(mm) polished by MRF is 1.2 nm(root mean square(RMS)),and the tool marks are completely removed.The surface accuracy by MRF is 0.035λ(RMS),and the low/middle-frequency errors are significantly corrected after MRF. 相似文献
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