Conventional approaches to control and shape the scattering pattems of light generated by different nanostructures are mostly based on engineering of their electric response due to the fact that most metallic nanostru...Conventional approaches to control and shape the scattering pattems of light generated by different nanostructures are mostly based on engineering of their electric response due to the fact that most metallic nanostructures support only electric resonances in the optical frequency range. Recently, fuelled by the fast development in the fields of metamaterials and plasmonics, artificial optically-induced magnetic responses have been demonstrated for various nanostructures. This kind of response can be employed to provide an extra degree of freedom for the efficient control and shaping of the scattering patterns of nanoparticles and nanoantennas. Here we review the recent progress in this research direction of nanoparticle scattering shaping and control through the interference of both electric and optically-induced magnetic responses. We discuss the magnetic resonances supported by various structures in different spectral regimes, and then summarize the original results on the scattering shaping involving both electric and magnetic responses, based on the interference of both spectrally separated （with different resonant wavelengths） and overlapped dipoles （with the same resonant wavelength）, and also other higher-order modes. Finally, we discuss the scattering control utilizing Fano resonances associated with the magnetic responses.展开更多
Regulation of optical properties and electronic structure of two-dimensionM layered ReS2 materials has attracted much attention due to their potential in electronic devices. However, the identification of structure tr...Regulation of optical properties and electronic structure of two-dimensionM layered ReS2 materials has attracted much attention due to their potential in electronic devices. However, the identification of structure transformation of monolayer ReS2 induced by strain is greatly lacking. In this work, the Raman spectra of monolayer ReS2 with external strain are determined theoretically based on the density function theory. Due to the lower structural symmetry, deformation induced by external strain can only regulate the Raman mode intensity but cannot lead to Raman mode shifts. Our calculations suggest that structural deformation induced by external strain can be identified by Raman scattering.展开更多
A Thomson scattering diagnostic system is under construction at the Joint Texas Experimental Tokamak（J-TEXT）. A 1064 nm Nd：YAG laser with 50 Hz repetition rate is used as the laser source. We have used a software f...A Thomson scattering diagnostic system is under construction at the Joint Texas Experimental Tokamak（J-TEXT）. A 1064 nm Nd：YAG laser with 50 Hz repetition rate is used as the laser source. We have used a software for careful and precise control of the laser through serial communication. A time sequence operating system has been developed to synchronize the laser control and data acquisition system with the central control system（CSS）. The system operates commands from the CSS of J-TEXT and generates triggers for the laser and data acquisition system in the proper sequence. It also measures an asynchronous time value that is needed for accurate time stamping. All functions are served by a field-programmable gate array development platform that is suitable for high-speed data and signal processing applications.Several embedded peripherals, including Ethernet and USB 2.0, provide communication with the CSS and the server.展开更多
Gold nanoparticles （NPs） of various shapes were synthesized by a one-step method at ambient temperature in the presence of NaCl. 2-mercaptosuccinic acid （MSA） was used as both reducing agent and stabilizing agent....Gold nanoparticles （NPs） of various shapes were synthesized by a one-step method at ambient temperature in the presence of NaCl. 2-mercaptosuccinic acid （MSA） was used as both reducing agent and stabilizing agent. The shapes of gold NPs were controllable by simply tuning S/Au ratio （S is from MSA molecule, and S/Au ratio is controlled by tuning the volume of added MSA solution）, and triangle, polygonal and spherical nanoparticles were obtained. This result suggested a new way to consider the effects of MSA on the growth of nanoparticles, which showed that MSA is a strong capping agent and facilitates more uniform growth of nanoparticles in every dimension. And other important factors on nanoparticles growth including NaCl and temperature were discussed. Furthermore, a typical probe molecule, 4-aminothiophenol （4-ATP） was used to test the surface-enhanced Raman scattering （SERS） activity of these gold NPs and the results indicated good Raman activity on these substrates. And the enhancement factor （EF） at 1078 cm^- 1 （a1） was estimated to be as large as 6.3 × 10^4 and 5.5 × 10^4 for triangular plates and truncated particles, respectively.展开更多
An automatic seam tracking system used in submerged arc welding is presented.In the system, the linear CCD vision sensor is installed in front of the welding torch. Laserstructure light emitted by the semiconductor la...An automatic seam tracking system used in submerged arc welding is presented.In the system, the linear CCD vision sensor is installed in front of the welding torch. Laserstructure light emitted by the semiconductor laser irradiates on a slant to work-piece surface andforms a structure light strip on work-piece surface. Scatter light of the strip is received bylinear CCD on top of the seam and the image information of seam can be obtained. By way of imageprocessing and applying Fuzzy-P controller in tracking process, automatic seam tracking has beenrealized accurately. Anti-disturbing ability of the system to work-piece surface status has beenenhanced largely by classified microadjustment of torch height.展开更多
基金Project supported by the Australian Research Council Center of Excellence for Ultrahigh Bandwidth Devices for Optical Systems(Grant No.CE110001018)the Future Fellowship(Grant No.FT110100037)
文摘Conventional approaches to control and shape the scattering pattems of light generated by different nanostructures are mostly based on engineering of their electric response due to the fact that most metallic nanostructures support only electric resonances in the optical frequency range. Recently, fuelled by the fast development in the fields of metamaterials and plasmonics, artificial optically-induced magnetic responses have been demonstrated for various nanostructures. This kind of response can be employed to provide an extra degree of freedom for the efficient control and shaping of the scattering patterns of nanoparticles and nanoantennas. Here we review the recent progress in this research direction of nanoparticle scattering shaping and control through the interference of both electric and optically-induced magnetic responses. We discuss the magnetic resonances supported by various structures in different spectral regimes, and then summarize the original results on the scattering shaping involving both electric and magnetic responses, based on the interference of both spectrally separated （with different resonant wavelengths） and overlapped dipoles （with the same resonant wavelength）, and also other higher-order modes. Finally, we discuss the scattering control utilizing Fano resonances associated with the magnetic responses.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61264008,61574080 and 61505085
文摘Regulation of optical properties and electronic structure of two-dimensionM layered ReS2 materials has attracted much attention due to their potential in electronic devices. However, the identification of structure transformation of monolayer ReS2 induced by strain is greatly lacking. In this work, the Raman spectra of monolayer ReS2 with external strain are determined theoretically based on the density function theory. Due to the lower structural symmetry, deformation induced by external strain can only regulate the Raman mode intensity but cannot lead to Raman mode shifts. Our calculations suggest that structural deformation induced by external strain can be identified by Raman scattering.
基金supported by the National Magnetic Confinement Fusion Science Program of China under Contract No.2015GB111001by National Natural Science Foundation of China(Grant No.11575067)
文摘A Thomson scattering diagnostic system is under construction at the Joint Texas Experimental Tokamak（J-TEXT）. A 1064 nm Nd：YAG laser with 50 Hz repetition rate is used as the laser source. We have used a software for careful and precise control of the laser through serial communication. A time sequence operating system has been developed to synchronize the laser control and data acquisition system with the central control system（CSS）. The system operates commands from the CSS of J-TEXT and generates triggers for the laser and data acquisition system in the proper sequence. It also measures an asynchronous time value that is needed for accurate time stamping. All functions are served by a field-programmable gate array development platform that is suitable for high-speed data and signal processing applications.Several embedded peripherals, including Ethernet and USB 2.0, provide communication with the CSS and the server.
基金supported by the National Natural Science Foundation of China under Grant No.21101146
文摘Gold nanoparticles （NPs） of various shapes were synthesized by a one-step method at ambient temperature in the presence of NaCl. 2-mercaptosuccinic acid （MSA） was used as both reducing agent and stabilizing agent. The shapes of gold NPs were controllable by simply tuning S/Au ratio （S is from MSA molecule, and S/Au ratio is controlled by tuning the volume of added MSA solution）, and triangle, polygonal and spherical nanoparticles were obtained. This result suggested a new way to consider the effects of MSA on the growth of nanoparticles, which showed that MSA is a strong capping agent and facilitates more uniform growth of nanoparticles in every dimension. And other important factors on nanoparticles growth including NaCl and temperature were discussed. Furthermore, a typical probe molecule, 4-aminothiophenol （4-ATP） was used to test the surface-enhanced Raman scattering （SERS） activity of these gold NPs and the results indicated good Raman activity on these substrates. And the enhancement factor （EF） at 1078 cm^- 1 （a1） was estimated to be as large as 6.3 × 10^4 and 5.5 × 10^4 for triangular plates and truncated particles, respectively.
文摘An automatic seam tracking system used in submerged arc welding is presented.In the system, the linear CCD vision sensor is installed in front of the welding torch. Laserstructure light emitted by the semiconductor laser irradiates on a slant to work-piece surface andforms a structure light strip on work-piece surface. Scatter light of the strip is received bylinear CCD on top of the seam and the image information of seam can be obtained. By way of imageprocessing and applying Fuzzy-P controller in tracking process, automatic seam tracking has beenrealized accurately. Anti-disturbing ability of the system to work-piece surface status has beenenhanced largely by classified microadjustment of torch height.
