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Dae-Su Lee Soon-Jong Jeong Eon-Cheol Park Jea-Sung Song 《Journal of Electroceramics》2006,17(2-4):505-508
Dielectric and piezoelectric properties of grain oriented (Bi0.5Na0.5)TiO3-BaTiO3 ceramics were investigated in a process that the templated grain growth and hot pressing methods were employed. A ceramic
composition in Bi-based perovskite structure family, (Bi0.5Na0.5)TiO3-BaTiO3, was chosen as a matrix material and plate shaped SrTiO3 as a template. To examine the combined process effect on piezoelectric properties, three processes, conventional solid reaction,
templated grain growth and the combine treatment of templated grain growth and hot-pressing, were compared. Specimen processed
by templated grain growth and hot pressing methods exhibited better piezoelectric coefficient, d
31 (−79.6 pC/N) and electromechanical coefficient, k
33 (0.35) than those of the other specimens, fabricated by solid reaction and templated grain growth, respectively. The improved
properties were attributed to reduction of pore existing in matrix, which is related to abnormal grain growth from SrTiO3 template and its resultant heterogeneous shrinkage. 相似文献
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考虑带姿势旋转的人脸的特征点检测问题,提出了一种基于谷算子得到眼睛的候选区域,用Gabor滤波和方差投影构造模糊模板检测出眼睛的位置,并利用二值图像数学形态学与投影的方法得到有姿势旋转的人脸特征点检测的算法。该算法利用软数学形态学构造了一种新的谷算子,用一种新的局域区域取二值化的方法对图像进行二值分割,提出了通过谷算子运算得到人脸谷极点的方法,减少了一些不稳定点的影响。实验表明,该算法具有很高的精度和很强的鲁棒性。 相似文献
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In this review, the progress made in the last ten years concerning the synthesis of porous carbon materials is summarized. Porous carbon materials with various pore sizes and pore structures have been synthesized using several different routes. Microporous activated carbons have been synthesized through the activation process. Ordered microporous carbon materials have been synthesized using zeolites as templates. Mesoporous carbons with a disordered pore structure have been synthesized using various methods, including catalytic activation using metal species, carbonization of polymer/polymer blends, carbonization of organic aerogels, and template synthesis using silica nanoparticles. Ordered mesoporous carbons with various pore structures have been synthesized using mesoporous silica materials such as MCM‐48, HMS, SBA‐15, MCF, and MSU‐X as templates. Ordered mesoporous carbons with graphitic pore walls have been synthesized using soft‐carbon sources that can be converted to highly ordered graphite at high temperature. Hierarchically ordered mesoporous carbon materials have been synthesized using various designed silica templates. Some of these mesoporous carbon materials have successfully been used as adsorbents for bulky pollutants, as electrodes for supercapacitors and fuel cells, and as hosts for enzyme immobilization. Ordered macroporous carbon materials have been synthesized using colloidal crystals as templates. One‐dimensional carbon nanostructured materials have been fabricated using anodic aluminum oxide (AAO) as a template. 相似文献