The optimum theory and methods were adopted to design the laser beam riding guidance anti tank missile's control system in the short run. Through building the mathematical model of system, selecting a proper meth...The optimum theory and methods were adopted to design the laser beam riding guidance anti tank missile's control system in the short run. Through building the mathematical model of system, selecting a proper method and taking advantage of computer's high speed calculation and logic traits, an optimal controller was designed. Simulation results showed that the designed control system has fair performance and it satisfies the tactical and technical requirements. The results also demonstrate that by the combination of the optimizing methods and the computer the control system could be designed as soon as possible.展开更多
A DSP-based control system for laser processing that enables the motion of laser beam in two dimensions,and the control of its power with PC or without PC is discussed.The operation and implementation of the control s...A DSP-based control system for laser processing that enables the motion of laser beam in two dimensions,and the control of its power with PC or without PC is discussed.The operation and implementation of the control system along with the rapid processing of image data are presented.The purpose of the control system is to operate the laser equipments in such a manner that various programmable laser control signals are available for vector and bitmap processing of characters and pictures.This control system makes the laser processing more intelligent and flexible and can be used for welding,marking and engraving by lasers.展开更多
In order to characterize optical turbulence,we have developed a single star SCIDAR(SSS)for measurement of the distribution of C2n with height.The SSS consists of a 40 cm telescope and a CCD camera for fast sampling of...In order to characterize optical turbulence,we have developed a single star SCIDAR(SSS)for measurement of the distribution of C2n with height.The SSS consists of a 40 cm telescope and a CCD camera for fast sampling of stellar scintillation pattern.Spatiotemporal auto and cross-correlation functions of the single star images are computed,providing vertical profiles of optical turbulence intensity C2n(h)and wind speed V(h).Using this new SSS experiment,profiles of turbulence can be obtained from the ground to the top of atmosphere,allowing the determination of seeing,isoplanatic angle and coherence time.Detailed characteristics of atmospheric optical turbulence are important for active and passive imaging,astronomical site testing,adaptive optics,laser communications,target tracking and designation,and laser beam control.We plan to improve the robotization of the SSS to be able to use it routinely even under harsh weather and altitude conditions that we expect to encounter on the high Tibetan plateau or at Dome A in Antarctica.SSS will also be applied for the site testing campaign of the future Chinese extremely large telescope.展开更多
Nowadays,the electromagnetic properties of artificial photonic materials can be well-tuned via designs over their composition and geometries.However,engineering the properties of artificial materials at the nanoscale ...Nowadays,the electromagnetic properties of artificial photonic materials can be well-tuned via designs over their composition and geometries.However,engineering the properties of artificial materials at the nanoscale is challenging and costly.Here we demonstrate a facile and low-cost method for fabricating large-area silver nanoparticle metasurfaces(AgNPMSs)by using the vectorial holography-mediated growth technique.The AgNPMS,which can be regarded as a hologram device,possesses excellent chiroptical properties.The vectorial holographic technique may open avenues for fabricating novel chiroptical metamaterials with large degrees of freedom,which can be further used for beam steering,photocatalysis,biosensing,etc.展开更多
文摘The optimum theory and methods were adopted to design the laser beam riding guidance anti tank missile's control system in the short run. Through building the mathematical model of system, selecting a proper method and taking advantage of computer's high speed calculation and logic traits, an optimal controller was designed. Simulation results showed that the designed control system has fair performance and it satisfies the tactical and technical requirements. The results also demonstrate that by the combination of the optimizing methods and the computer the control system could be designed as soon as possible.
文摘A DSP-based control system for laser processing that enables the motion of laser beam in two dimensions,and the control of its power with PC or without PC is discussed.The operation and implementation of the control system along with the rapid processing of image data are presented.The purpose of the control system is to operate the laser equipments in such a manner that various programmable laser control signals are available for vector and bitmap processing of characters and pictures.This control system makes the laser processing more intelligent and flexible and can be used for welding,marking and engraving by lasers.
基金supported by the National Natural Science Foundation of China(10903014 and 11073031)the Young Researcher Grant of National Astronomical Observatories,Chinese Academy of Sciences
文摘In order to characterize optical turbulence,we have developed a single star SCIDAR(SSS)for measurement of the distribution of C2n with height.The SSS consists of a 40 cm telescope and a CCD camera for fast sampling of stellar scintillation pattern.Spatiotemporal auto and cross-correlation functions of the single star images are computed,providing vertical profiles of optical turbulence intensity C2n(h)and wind speed V(h).Using this new SSS experiment,profiles of turbulence can be obtained from the ground to the top of atmosphere,allowing the determination of seeing,isoplanatic angle and coherence time.Detailed characteristics of atmospheric optical turbulence are important for active and passive imaging,astronomical site testing,adaptive optics,laser communications,target tracking and designation,and laser beam control.We plan to improve the robotization of the SSS to be able to use it routinely even under harsh weather and altitude conditions that we expect to encounter on the high Tibetan plateau or at Dome A in Antarctica.SSS will also be applied for the site testing campaign of the future Chinese extremely large telescope.
基金the National Natural Science Foundation of China(62075093 and 61805113)the Guangdong Innovative and Entrepreneurial Research Team Program(2017ZT07C071)+1 种基金the Natural Science Foundation of Guangdong Province(2017A030313034 and 2018A030310224)Shenzhen Science and Technology Innovation Commission(JCYJ20170817111349280,JCYJ20180305180635082,and GJHZ20180928155207206)。
文摘Nowadays,the electromagnetic properties of artificial photonic materials can be well-tuned via designs over their composition and geometries.However,engineering the properties of artificial materials at the nanoscale is challenging and costly.Here we demonstrate a facile and low-cost method for fabricating large-area silver nanoparticle metasurfaces(AgNPMSs)by using the vectorial holography-mediated growth technique.The AgNPMS,which can be regarded as a hologram device,possesses excellent chiroptical properties.The vectorial holographic technique may open avenues for fabricating novel chiroptical metamaterials with large degrees of freedom,which can be further used for beam steering,photocatalysis,biosensing,etc.
