TH742 97053463大视场高分辨率激光束扫描显微成像理论和设计若干问题的讨论=Theory of large—field and highresolution laser scanning microimaging andsome problems concerned in design[刊,中]/邱锦辉(福建师范大学激光研究所.福...TH742 97053463大视场高分辨率激光束扫描显微成像理论和设计若干问题的讨论=Theory of large—field and highresolution laser scanning microimaging andsome problems concerned in design[刊,中]/邱锦辉(福建师范大学激光研究所.福建,福州(350007))∥福光技术.—1996,(22).—43该文认为采用亮视场共焦、暗视场(较高频)和微细节视场(高频)的多视场及其组合,也是实现图像高精度重现物体频谱的有效技术途径。(赵桂云)TH742 97053464激光显微系统设计技术研究=Design of laser microsystem[刊,中]/钟快醒,王尔祺,宋德慧∥福光技术.—1996,(22).—75从仪器分析入手,讨论了仪器的系统构成。展开更多
This research focuses on measuring the mode transformation and energy attenuation of wedge waves for different apex angle wedges by using laser ultrasound techniques.Pulsed laser excitation and optical deflection beam...This research focuses on measuring the mode transformation and energy attenuation of wedge waves for different apex angle wedges by using laser ultrasound techniques.Pulsed laser excitation and optical deflection beam methods for detection were used to measure the wedge waves.In experiment,various wedge waves at different locations were recorded by scanning the excitation laser along the wedge tip,and different orders of wedge waves were observed.By fixing the distance between the excitation and detection positions and scanning the samples along the direction normal to the wedge tip,the modes transformation process was obtained.It was found that the energy of the acoustic waves for 20°,25° and 30° wedges decreased exponentially to a steady energy of Rayleigh wave within the main wavelength range of the acoustic modes,while the energy of acoustic waves of 45° and 60° wedge remained stable as the propagation line was scanned away from the wedge tip.展开更多
For laser surface hardening of metal components with large superficies,a binary grating is proposed to generate single-row laser beam with proportional-intensity diffractive orders.To obtain a uniform hardened band di...For laser surface hardening of metal components with large superficies,a binary grating is proposed to generate single-row laser beam with proportional-intensity diffractive orders.To obtain a uniform hardened band distribution and improve the wear resistance of the sample surface,the binary grating is designed to produce single-row laser beam with energy strengthened at the two ends.The profile of the laser beam spot was designed to be strip with high length-width ratio to improve the machining efficiency of the hardening of large surfaces.A new advantage is suggested to obtain proportional intensity spots with evenness.The design results show that the diffractive efficiency of the binary grating is more than 70%,and the uniformity is less than 3%.The surface profile of the grating fabricated was measured,which shows that the fabrication error is less than 2%.The application of the binary grating in the laser surface hardening of metal components with large superficies is experimentally investigated,and the results show that the hardness distribution of the modified layer is more uniform than that hardened by Gaussian laser beam or array spots with equal intensity distribution.展开更多
文摘TH742 97053463大视场高分辨率激光束扫描显微成像理论和设计若干问题的讨论=Theory of large—field and highresolution laser scanning microimaging andsome problems concerned in design[刊,中]/邱锦辉(福建师范大学激光研究所.福建,福州(350007))∥福光技术.—1996,(22).—43该文认为采用亮视场共焦、暗视场(较高频)和微细节视场(高频)的多视场及其组合,也是实现图像高精度重现物体频谱的有效技术途径。(赵桂云)TH742 97053464激光显微系统设计技术研究=Design of laser microsystem[刊,中]/钟快醒,王尔祺,宋德慧∥福光技术.—1996,(22).—75从仪器分析入手,讨论了仪器的系统构成。
基金supported by the National Natural Science Foundation of China (Grant Nos. 60878023 and 61108013)the program for New Century Excellent Talents in University (NCET)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘This research focuses on measuring the mode transformation and energy attenuation of wedge waves for different apex angle wedges by using laser ultrasound techniques.Pulsed laser excitation and optical deflection beam methods for detection were used to measure the wedge waves.In experiment,various wedge waves at different locations were recorded by scanning the excitation laser along the wedge tip,and different orders of wedge waves were observed.By fixing the distance between the excitation and detection positions and scanning the samples along the direction normal to the wedge tip,the modes transformation process was obtained.It was found that the energy of the acoustic waves for 20°,25° and 30° wedges decreased exponentially to a steady energy of Rayleigh wave within the main wavelength range of the acoustic modes,while the energy of acoustic waves of 45° and 60° wedge remained stable as the propagation line was scanned away from the wedge tip.
基金supported by the China Postdoctoral Science Foundation Funded Project (Grant No. 201104092)
文摘For laser surface hardening of metal components with large superficies,a binary grating is proposed to generate single-row laser beam with proportional-intensity diffractive orders.To obtain a uniform hardened band distribution and improve the wear resistance of the sample surface,the binary grating is designed to produce single-row laser beam with energy strengthened at the two ends.The profile of the laser beam spot was designed to be strip with high length-width ratio to improve the machining efficiency of the hardening of large surfaces.A new advantage is suggested to obtain proportional intensity spots with evenness.The design results show that the diffractive efficiency of the binary grating is more than 70%,and the uniformity is less than 3%.The surface profile of the grating fabricated was measured,which shows that the fabrication error is less than 2%.The application of the binary grating in the laser surface hardening of metal components with large superficies is experimentally investigated,and the results show that the hardness distribution of the modified layer is more uniform than that hardened by Gaussian laser beam or array spots with equal intensity distribution.
