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51.
52.
一种固定阈值的毫米波图像边缘检测方法 总被引:1,自引:0,他引:1
文章提出了一种固定阈值的毫米波图像边缘检测方法。根据图像的统计特征确定出像素的标准梯度强度,并采用单阈值对图像进行边缘粗定位,然后施行非最大抑制处理和滤波,得到最终检测结果。由于该算法对各幅毫米波图像设置相同的阈值,故能实现自动检测,同时还具有计算量小的特点。实验结果表明该方法进行毫米波图像边缘检测的有效性和可行性。 相似文献
53.
Raphaëlle Savoire Jean‐Louis Lanoisellé Hélène Ducatel Eugène Vorobiev 《European Journal of Lipid Science and Technology》2008,110(8):725-734
Seven linseed varieties were harvested at seven times before complete maturity. Microscale oilseed expressions were subsequently carried out on it. A pressure of 10 MPa was applied for 1 h under uniaxial stress. The results were characterized in terms of oil, water and mucilage content, harvest date and oil yield. The piston displacement versus time (creep curves) was described by a four‐Kelvin‐Voigt elements viscoelastic model. Parameters were derived from the model, such as the mechanical properties of seeds (compressibility moduli), showing that the viscoelastic model fits well the experimental data (R² ≈ 0.999). The modeling parameters were combined with some biochemical data in order to predict the kinetics of oil extraction. 相似文献
54.
介绍了武钢热轧厂烟气中残氧量自动监测技术及燃烧工艺试验 ,评述该项技术研究动态 ,指出它对节能降耗和环境保护的作用 相似文献
55.
P J?k?l? M Riekkinen M Bj?rklund E Koivisto B Schmidt P Riekkinen 《Canadian Metallurgical Quarterly》1996,318(2-3):239-250
The present study investigated if short-term treatment with an L-type Ca2+-channel inhibitor, nimodipine, can stimulate cognitive functioning and cortical electroencephalograph (EEG) arousal, and potentiate the effect of a cholinesterase inhibitor, metrifonate. Pretraining administration of nimodipine (3, 10 and 30 mg/kg, p.o.) had no effect on water maze and passive avoidance behavior of young neurologically intact controls, or water maze and passive avoidance performance failure induced by scopolamine pretreatment (i.p.; 0.4 mg/kg during the water maze and 2.0 mg/kg during the passive avoidance study), medial septal lesioning, or aging. Furthermore, nimodipine (3, 10 and 30 mg/kg, p.o.) had no effect on the improvement by metrifonate (10 mg/kg, p.o.) of the water maze and passive avoidance failure induced by scopolamine pretreatment or medial septal lesioning, nor did it affect the potential of metrifonate (30 mg/kg. p.o.) to improve the water maze or passive avoidance behavior of aged rats. Finally, nimodipine (3, 10 and 30 mg/kg, p.o.) had no effect on spontaneously occurring thalamically generated neocortical high-voltage spindles or spectral EEG activity of young controls, nor did it alleviate the spectral EEG abnormality induced by scopolamine (0.2 mg/kg, i.p.) administration. Also, the combination of nimodipine 3 or 10 mg/kg and a subthreshold dose of metrifonate 10 mg/kg could not suppress high-voltage spindles or scopolamine treatment-induced spectral EEG activity abnormalities. According to the present results, short-term treatment with nimodipine does not stimulate cognitive functions or increase cortical EEG arousal, and does not block or potentiate the propensity of metrifonate to improve cognitive performance of rats. 相似文献
56.
Zakaria Chajar Michel Primet Hélène Praliaud Michèle Chevrier Catherine Gauthier Frédéric Mathis 《Catalysis Letters》1994,28(1):33-40
The role of nitrogen dioxide in the selective reduction of NO by propane over a Cu-MFI zeolite is investigated. NO2 and NO reductions were carried out under similar conditions of reaction. In the presence of oxygen, the reduction of NO by C3H8 does not differ significantly from that of NO2. In the absence of oxygen, the reduction of NO2 by propane occurs with a partial decomposition of the nitric dioxide molecule. Such a decomposition leads to the formation of oxygen, which is responsible for the increase in catalytic activity by comparison with the same reaction performed with NO. NO2 formed and released in the gas phase during the reduction of NO by propane in the presence of oxygen does not play a predominant role in the catalytic process. 相似文献
57.
Novel compounds RETSb2 have been prepared and characterized for T Cu (RE rare earth from La to Lu), Ni (RE La to Ho), Pd (RE La to Tb) and Au (RE La to Sm). From X-ray powder diffraction analyses all compounds were found to crystallize as the ZrCuSi2 type. Magnetic susceptibilities were generally measured in the temperature range from 4 to 100 K. YCuSb2 and LaTSbz are temperature-independent paramagnets. RETSb2 compounds are found to order antiferromagnetically below T = 20 K. PrPdSb2 and TbPdSb2 undergo metamagnetic transitions, whereas PrCuSb2 and ErCuSb2 are simple ferromagnets. The Sm-containing compounds are typical Van Vleck paramagnets owing to the closely spaced multiplets. 相似文献
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