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The polarization transform errors of two-waveplate polarization state transformers (TWPST), which consist of quarter-waveplate (QWP) and half-waveplate (HWP), are discussed in detail. The error model of the TWPST based on a new and simple two dimensions geometry method instead of traditional Poincaré sphere method or Jones matrix method are proposed. We did the numerical calculations based on the error model of the TWPST. The results show that the output polarization state errors of the TWPST are chiefly sensitive to the azimuth angle errors of the QWP, and that there exist a pair of optimal error azimuth angles of QWP and HWP, which can minimize the azimuth angle error of the output polarization state of TWPST, and that the ellipticity error of output polarization state of TWPST is dependent only on the azimuth angle errors of QWP. The TWPST have enough accuracy to evaluate the polarization related effects (PRE) in the optical communication systems. 相似文献
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针对多组分气体测量精度低、交叉影响等问题,建立了一种高精度多气体网络式在线检测系统。系统中采用窄线宽激光器作为光源,设计了新型长光程气室,通过单一高频三角信号调制激光光谱,利用谐波检测技术和光学时分、空分复用技术相结合,实现了三种气体(CO,CH4,C2H2)的同时多点高精度在线测量。实验结果表明,多气体浓度测量最大相对误差小于4%,每种气体响应时间均小于15 s。该系统多气体检测精度高、响应时间快,非常适合用于变压器绝缘油中多组分气体实时在线检测。 相似文献
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Estimating the tensile strength of super hard brittle materials using truncated spheroidal specimens
New approaches need to be introduced to measure the tensile capacity of super hard materials since the standard methods are not effective. To pursue this objective, a series of laboratory tests were constructed to replicate the fracture mechanism of diamond-based materials. Experiments indicate that under a certain compressive test condition, stresses normal to the axisymmetric line in truncated spheroidal specimens (bullet-shaped specimens) are in tension contributing to the tensile fracture of the material. From experimental and numerical studies, it is concluded that semi-prolate spheroidal specimens can be used to determine precisely the tensile strength of brittle stiff diamond-like composites. 相似文献
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介绍以小信号正弦电磁激振和脉冲设击激振,加速度计进行信号检测的扭振超声变幅杆谐振频率和角位移放大系数的测定方法。该法已应用于科研试验中。 相似文献