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排序击中击不中变换及其光学实现   总被引:3,自引:0,他引:3  
程惠全  刘立人  景红梅  汪澄 《光学学报》1999,19(9):251-1256
基于对形态学灰度排序击中击不中变换的取阈方法的研究,提出了单通道排序击中击不中变换,探讨了相应的光学实现,与码编码击不击不中变换相比,由于仅仅使用了原始图像因而更于光学实现,扩大了以击中击不中变换为基础的光学数学形态学处理系统的容噪性和自理能力。  相似文献
2.
Synthesis and characterization of CdS/PVA nanocomposite films   总被引:1,自引:0,他引:1  
A series CdS/PVA nanocomposite films with different amount of Cd salt have been prepared by means of the in situ synthesis method via the reaction of Cd2+-dispersed poly vinyl-alcohol (PVA) with H2S. The as-prepared films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) absorption, photoluminescence (PL) spectra, Fourier transform infrared spectroscope (FTIR) and thermogravimetric analysis (TGA). The XRD results indicated the formation of CdS nanoparticles with hexagonal phase in the PVA matrix. The primary FTIR spectra of CdS/PVA nanocomposite in different processing stages have been discussed. The vibrational absorption peak of CdS bond at 405 cm−1 was observed, which further testified the generation of CdS nanoparticles. The TGA results showed incorporation of CdS nanoparticles significantly altered the thermal properties of PVA matrix. The photoluminescence and UV-vis spectroscopy revealed that the CdS/PVA films showed quantum confinement effect.  相似文献
3.
逻辑函数形态学算子用于光学二元图像处理   总被引:1,自引:0,他引:1  
景红梅  汪澄  刘立人 《光学学报》2000,20(5):09-616
提出了用于二元图像处理的逻辑函数形态学的概念。在逻辑函数形态学中,认为图像和结构核是逻辑函数,用16个逻辑算子替代图像和结构之间在相关运算中的“乘积”,共得到12个逻辑函数形态学算子。描述了逻辑形态学的光学实现,同时给出了实验结果。  相似文献
4.
A series CdS/PVA nanocomposite films with different amount of Cd salt have been prepared by means of the in situ synthesis method via the reaction of Cd2+-dispersed poly vinyl-alcohol (PVA) with H2S. The as-prepared films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) absorption, photoluminescence (PL) spectra, Fourier transform infrared spectroscope (FTIR) and thermogravimetric analysis (TGA). The XRD results indicated the formation of CdS nanoparticles with hexagonal phase in the PVA matrix. The primary FTIR spectra of CdS/PVA nanocomposite in different processing stages have been discussed. The vibrational absorption peak of CdS bond at 405 cm−1 was observed, which further testified the generation of CdS nanoparticles. The TGA results showed incorporation of CdS nanoparticles significantly altered the thermal properties of PVA matrix. The photoluminescence and UV-vis spectroscopy revealed that the CdS/PVA films showed quantum confinement effect.  相似文献
5.
A diode-pumped passively Q-switched Nd:YLF laser was demonstrated by using saturable absorber of Cr4+:YAG. At the incident power of 7.74 W, pure passively Q-switched laser with per pulse energy of 210 Μj and pulse width of 19.6 ns at repetition rate of 1.78 kHz was obtained by using Cr4+:YAG with initial transmission of 80%. At the incident power of 8.70 W, a Q-switched mode-locking with average output power of 650 Mw was achieved, the overall slop efficiency was 16%, corresponding to the initial transmission of 85% of Cr4+ :YAG.  相似文献
6.
国际热核实验反应堆ITER计划是一项大型国际研究合作项目。中子屏蔽组件位于真空室内、外壳之间,其作用是屏蔽中子流、降低环向磁场波纹度。文中以中子屏蔽组件为研究对象,研究在烘烤温度下预紧力对其力学性能的影响。运用ANSYS软件对中子屏蔽组件进行非线性有限元计算,对比分析了在不同预紧力下螺栓的变形和结构的应力响应。研究表明,为了增强连接的紧密性,在保证结构完整性和螺栓强度的前提下充分利用螺栓的预紧力,应将预紧力产生的预紧应力控制在材料屈服应力的60%左右。  相似文献
7.
无论是光路交换还是光突发交换,都离不开有光开关矩阵组成的光交叉连接节点(OXC).OXC节点是组建波分复用光网络的基本单元,OXC节点引入的串扰成为限制其投入实用的主要原因.理论分析了基于扩展Benes(DB)结构和改进扩展Benes(GMDB)结构的三种典型OXC结构中的带内串扰,结果表明基于DB结构和GMDB结构的OXC节点可以完全消除低于二阶的各类串扰.数值模拟了基于两种结构的OXC节点中带内串扰的积累特性,发现基于GMDB结构的OXC节点能大大降低串扰引起的功率代价,实验测量了8×8DB结构和GMDB结构中串扰的影响,实验结果证实了GMDB结构的低串扰特点.同时与基于DB结构的OXC节点相比,基于GMDB结构的OXC节点对光开关串扰系数的要求放宽了5 dB,大大降低了对光开关隔离度的要求.  相似文献
8.
A new electrochemical procedure for the electrocatalytic dimerisation of benzoyl chloride in ionic liquid, 1‐butyl‐3‐methylimidazoliumtetrafluoborate, to benzil was investigated for the first time. The electrochemical behavior of benzoyl chlorides in BMIMBF4 was studied by cyclic voltammetry with a reduction peak at −1.2 V (vs Ag). The electrolysis experiments were carried out in an undivided cell under mild conditions without any toxic solvents, catalysts and supporting electrolytes, creating benzil at a moderate yield (51%). The results showed that the yields were strongly affected by various factors: temperature, working potential, electrode material. Moreover, the ionic liquid was successfully recycled for this reaction. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献
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