共查询到18条相似文献,搜索用时 78 毫秒
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为了有效抑制高于CCD或者CMOS传感器的图像采样频率而出现的莫尔条纹,研制了一种二维三明治式双折射低通滤波器(OLPF)。其主要由三片双折射晶体平板构成三明治结构,并在前、后表面分别镀上红外截止膜和增透膜。对所研制的二维水晶光学低通滤波器进行了实验测试,空间频率测试表明对莫尔条纹有良好的抑制效果。结果表明,所研制的低通滤波器具有很高的自洁净性,与后端的CCD或者CMOS传感器匹配良好,对空间高频有较强的抑制作用。 相似文献
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光学镜面离子束加工的材料去除效率 总被引:1,自引:0,他引:1
分析了离子束加工光学镜面的材料去除效率和不I司材料之间的相对去除效率与工艺参数的关系.基于Sigmund 溅射理论.建立了表征去除效率的指标一法向去除速率、体积去除速率和溅射产额与束能、束流以及入射角度之间的关系模型.以石英、微晶和K4玻璃等为样件,实验分析了去除效率与工艺参数的关系,验证了模型的正确性.分析结果表明,材料去除效率随束流线性增大,与束能平方根约呈线性关系;随着入射角度先缓慢增大,约在60~80°达到最大值.然后迅速降为0.不同材料之间的相对去除效率与束流无关;与束能的关系较弱,可以忽略;随角度变化较为明显. 相似文献
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红外地球敏感器用高截止度宽带红外滤光片研制 总被引:1,自引:0,他引:1
高截止度宽带红外滤光片是新型红外地球敏感器的关键件之一.介绍了高截止度宽带红外滤光片的设计方法和镀膜的工艺技术,给出了膜系设计和研制的结果,并与国内外同类滤光片的光学特性进行了比较,试验表明这种红外滤光片的膜系设计是成功的. 相似文献
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高截止度宽带红外滤光片是新型红外地球敏感器的关键件之一。介绍了高截止度宽带红外滤光片的设计方法和镀膜的工艺技术 ,给出了膜系设计和研制的结果 ,并与国内外同类滤光片的光学特性进行了比较 ,试验表明这种红外滤光片的膜系设计是成功的 相似文献
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高截止度宽带红外滤光片是新型红外地球敏感器的关键件之一.介绍了高截止度宽带红外滤光片的设计方法和镀膜的工艺技术,给出了膜系设计和研制的结果,并与国内外同类滤光片的光学特性进行了比较,试验表明这种红外滤光片的膜系设计是成功的. 相似文献
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分析了离子束加工材料去除效率、不同材料之间的相对去除效率与工艺参数的关系。基于Sigmund溅射理论,建立表征去除效率的指标-法向去除率、体积去除率和溅射产额与束能、束流以及入射角度之间的关系模型。以石英、微晶和K4等为样件,实验分析了去除效率与工艺参数的关系,验证了模型的正确性。分析结果表明材料去除效率随束流线性增大;约与束能平方根呈线性关系;随着入射角度先缓慢增大,约在60~80°达到最大值,尔后迅速降为零。不同材料之间的相对去除效率与束流无关;与束能的关系较弱,可以忽略;随角度变化较为明显。 相似文献
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This paper describes a mini linear optical pickup actuator. To reduce the size, inner yokes are designed to guide the mover
and outer yokes of permanent magnets are removed. Magnetic circuit method is used to determine the thrust force. Virtual path
method is proposed to analyze the open magnetic circuit analysis. The magnetic circuit of the proposed actuator can be a closed
circuit due to the virtual path model of the outer magnetic flux. The validity of virtual path method is evaluated by comparing
to the FEM analysis. Structural vibration is investigated using FEM and the design of the mover is modified to improve the
vibration characteristic. Dynamic characteristic experiments shows that the performance of the proposed actuator is enough
to be used as a coarse and fine seeking actuator simultaneously and the thrust force margin for loading a focusing actuator
is guaranteed. 相似文献
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大面阵中波红外连续变焦光学系统设计 总被引:6,自引:0,他引:6
针对制冷式大面阵640×512凝视焦平面阵列探测器,设计了一套中波红外连续变焦光学系统。该系统由变焦系统和二次成像系统构成,包括7片透镜和2个反射镜组成的折叠光路。首先,根据变焦原理和专业光学设计软件给出了系统结构及其参数。然后,分析了系统的像质和冷反射效应。最后,验证了系统的性能指标。结果表明:该系统可以实现50~500mm的连续变焦,变焦过程中目标景物始终清晰可见;系统在耐奎斯特频率处的全视场光学传递函数大于0.35,全视场畸变小于2%,无冷反射现象;具有分辨率高、热灵敏度高、像质好、变焦轨迹平滑等特点,基本满足设计要求。 相似文献
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In this paper, a novel Tilt Integral Derivative controller with Filter (TIDF) is proposed for Load Frequency Control (LFC) of multi-area power systems. Initially, a two-area power system is considered and the parameters of the TIDF controller are optimized using Differential Evolution (DE) algorithm employing an Integral of Time multiplied Absolute Error (ITAE) criterion. The superiority of the proposed approach is demonstrated by comparing the results with some recently published heuristic approaches such as Firefly Algorithm (FA), Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) optimized PID controllers for the same interconnected power system. Investigations reveal that proposed TIDF controllers provide better dynamic response compared to PID controller in terms of minimum undershoots and settling times of frequency as well as tie-line power deviations following a disturbance. The proposed approach is also extended to two widely used three area test systems considering nonlinearities such as Generation Rate Constraint (GRC) and Governor Dead Band (GDB). To improve the performance of the system, a Thyristor Controlled Series Compensator (TCSC) is also considered and the performance of TIDF controller in presence of TCSC is investigated. It is observed that system performance improves with the inclusion of TCSC. Finally, sensitivity analysis is carried out to test the robustness of the proposed controller by varying the system parameters, operating condition and load pattern. It is observed that the proposed controllers are robust and perform satisfactorily with variations in operating condition, system parameters and load pattern. 相似文献