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The micro-electro-mechanical system (MEMS) acoustic film has extremely high requirements for tape-out, storage and packaging environments, and its surface defects will affect the quality and performance of MEMS devices. The image defects detection is an effective non-contact optical detection means that can effectively improve the yield rate of MEMS production. However, the periodic structure texture of the MEMS devices surface will interfere with defect detection. A acoustic film defect detection algorithm based on frequency domain transformation was proposed. By calculating the gradient distribution of spectrogram and establishing the Boolean mask, the dominant frequency components corresponding to the periodic structure texture were eliminated. The residual spectrograms were subjected to a Fourier inversion to reconstruct the defect images. The reconstructed images were decomposed by single-layer Haar wavelet to obtain the low-frequency sub-band image and the defect information was extracted by simple threshold segmentation. The defect detection effects of different types of MEMS acoustic film were showed. The experimental results show that it is reasonable to set the zoom constant in the range of 0.7~1.0. 相似文献
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合成了阿司匹林铜(Ⅱ)配合物,通过红外、X射线单晶衍射对其结构进行了表征。配合物属单斜晶系,P21/n空间群,晶胞参数为a=8.211(5)nm,b=10.419(5)nm,c=21.003(5)nm,β=98.021(5)°,V=1779.2(14)nm3,Z=4。采用紫外光谱和荧光光谱法及循环伏安法研究了配合物与小牛胸腺DNA(ct-DNA)的相互作用。采用MTT法测定了配合物对体外培养人乳腺癌MCF-7和胃癌MGC-803细胞的抑制活性。当配合物浓度为120μmol/L时,对2种细胞增殖的抑制率分别为80.01%和70.16%。 相似文献
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