By analyzing the deficiencies of the method, a measurement system with the technologies of photoelectricity, laser and digital image processing to synthetically measure these two parameters has been developed. A tradi...By analyzing the deficiencies of the method, a measurement system with the technologies of photoelectricity, laser and digital image processing to synthetically measure these two parameters has been developed. A traditional method to measure the swaying quantity and multi-barrel parallelism of rocket launcher is introduced. Meanwhile, the principle, executive plan and the accuracy analysis are also presented. The photoelectric measurement system has been applied in the swaying quantity and multi-barrel parallelism measurement for Φ122 mm and Φ302 mm rocket launcher. The metrical errors are both 16^th.展开更多
It is considered the mechanism of streamer discharge in the wide-gap semiconductors as a highly effective method of the laser excitation on the basis of representation about the phenomenon of light self-trapping of th...It is considered the mechanism of streamer discharge in the wide-gap semiconductors as a highly effective method of the laser excitation on the basis of representation about the phenomenon of light self-trapping of the discharge, providing their high propagation velocity down to v- 5 ×10^9 sm/s, the crystallographic orientation, filamentary character at thickness of the channel about 1 μm and absence of destructions of a crystal.展开更多
To improve the light-extraction-efficiency of OLED,we introduced PCS (Photonic Crystal Slab) structures into the interface of ITO layer and glass substrate.PCS structures with Taper unit cells are proved to be effecti...To improve the light-extraction-efficiency of OLED,we introduced PCS (Photonic Crystal Slab) structures into the interface of ITO layer and glass substrate.PCS structures with Taper unit cells are proved to be effective in reducing the energy of guided wave trapped in high refractive index material,and an increase of light-extraction-efficiency to 95.26% is gained.This enhancement is much greater than the traditional PCS with cylinder unit cells (60%-70%).Physical mechanisms of light-extraction-efficiency enhancement in these structures are further discussed.展开更多
With brief statements of the linear electro-optical modulation and magnetooptical modulation, using the method of resultant of optical amplitude vectors and the methed of Jones matrix, formulas for intensity of transm...With brief statements of the linear electro-optical modulation and magnetooptical modulation, using the method of resultant of optical amplitude vectors and the methed of Jones matrix, formulas for intensity of transmitted light through the optical analyzer of various composition of electro-optical effect with magneto-optical effect are derived. The results show that the output beam from the analyzer carries information on current (or magnetic field), voltage (or electric field), active power and apparent power. When the light beam transmitted through the analyzer are transformed into electric signals, three kinds of information are included: the DC term corresponding to an active power, the term with frequency ω(50 Hz) corresponding to current or voltage, and the term with frequency 2ω(100 Hz) corresponding to an apparnt power.So, we can use the electric filter circuit to pick out the DC component for measuring active power; to pick out the component with frequency ω(50 Hz) for measuring current or voltage; and to pick out the component with frequency 2ω(100 Hz) for measuring apparent power. The paper discusses what quantities are measured when the analyzer is set on certain definite values, and ponts out the optimum selection for various measurements.展开更多
Exotic quantum phenomena may appear in material systems with multiple orders or phases,where the mutual interactions can give rise to new physics beyond that of each component.Here,we report spectroscopic evidence for...Exotic quantum phenomena may appear in material systems with multiple orders or phases,where the mutual interactions can give rise to new physics beyond that of each component.Here,we report spectroscopic evidence for a unique combination of topology and correlation effects in the kagome superconductor CsV_(3)Sb_(5).Topologically nontrivial surface states are observed near the Fermi energy(E_(F)),indicating that the topological physics may be active upon entering the superconducting state.Flat bands are observed,suggesting that electron correlation effects are also at play in this system.Our results reveal the peculiar electronic structure of CsV_(3)Sb_(5),which holds the potential for realizing Majorana zero modes and anomalous superconducting states in kagome lattices.They also establish CsV_(3)Sb_(5)as a unique platform for exploring the interactions between the charge order,topology,correlation effects and superconductivity.展开更多
Mechanoluminescent(ML)materials can directly convert external mechanical stimulation into light without the need for excitation from other forms of energy,such as light or electricity.This alluring characteristic make...Mechanoluminescent(ML)materials can directly convert external mechanical stimulation into light without the need for excitation from other forms of energy,such as light or electricity.This alluring characteristic makes ML materials potentially applicable in a wide range of areas,including dynamic imaging of force,advanced displays,information code,storage,and anti-counterfeiting encryption.However,current reproducible ML materials are restricted to sulfide-and oxide-based materials.In addition,most of the reported ML materials require pre-irradiation with ultraviolet(UV)lamps or other light sources,which seriously hinders their practical applications.Here,we report a novel ML material,MgF_(2):Mn^(2+),which emits bright red light under an external dynamic force without the need for pre-charging with UV light.The luminescence properties were systematically studied,and the piezophotonic application was demonstrated.More interestingly,unlike the well-known zinc sulfide ML complexes reported previously,a highly transparent ML film was successfully fabricated by incorporating MgF_(2):Mn^(2+)into polydimethylsiloxane(PDMS)matrices.This film is expected to find applications in advanced flexible optoelectronics such as integrated piezophotonics,artificial skin,athletic analytics in sports.展开更多
We investigate theoretically the electron-reflection phenomenon in a graphene n＋n junction based on electron optics, where the local potential in the left n ＋ region is higher than that in the right n region. It is ...We investigate theoretically the electron-reflection phenomenon in a graphene n＋n junction based on electron optics, where the local potential in the left n ＋ region is higher than that in the right n region. It is demonstrated numerically that electrons emitting from a point source in the n ＋ region will experience total internal reflection through the interface of the junction. The reflection becomes stronger and the transmission becomes weaker with decrease of the local potential in the right graphene ribbon. It is also found that when a nonideal interface is considered in the junction, the electron-reflection effect is enhanced due to interracial backseattering.展开更多
文摘By analyzing the deficiencies of the method, a measurement system with the technologies of photoelectricity, laser and digital image processing to synthetically measure these two parameters has been developed. A traditional method to measure the swaying quantity and multi-barrel parallelism of rocket launcher is introduced. Meanwhile, the principle, executive plan and the accuracy analysis are also presented. The photoelectric measurement system has been applied in the swaying quantity and multi-barrel parallelism measurement for Φ122 mm and Φ302 mm rocket launcher. The metrical errors are both 16^th.
文摘It is considered the mechanism of streamer discharge in the wide-gap semiconductors as a highly effective method of the laser excitation on the basis of representation about the phenomenon of light self-trapping of the discharge, providing their high propagation velocity down to v- 5 ×10^9 sm/s, the crystallographic orientation, filamentary character at thickness of the channel about 1 μm and absence of destructions of a crystal.
文摘To improve the light-extraction-efficiency of OLED,we introduced PCS (Photonic Crystal Slab) structures into the interface of ITO layer and glass substrate.PCS structures with Taper unit cells are proved to be effective in reducing the energy of guided wave trapped in high refractive index material,and an increase of light-extraction-efficiency to 95.26% is gained.This enhancement is much greater than the traditional PCS with cylinder unit cells (60%-70%).Physical mechanisms of light-extraction-efficiency enhancement in these structures are further discussed.
文摘With brief statements of the linear electro-optical modulation and magnetooptical modulation, using the method of resultant of optical amplitude vectors and the methed of Jones matrix, formulas for intensity of transmitted light through the optical analyzer of various composition of electro-optical effect with magneto-optical effect are derived. The results show that the output beam from the analyzer carries information on current (or magnetic field), voltage (or electric field), active power and apparent power. When the light beam transmitted through the analyzer are transformed into electric signals, three kinds of information are included: the DC term corresponding to an active power, the term with frequency ω(50 Hz) corresponding to current or voltage, and the term with frequency 2ω(100 Hz) corresponding to an apparnt power.So, we can use the electric filter circuit to pick out the DC component for measuring active power; to pick out the component with frequency ω(50 Hz) for measuring current or voltage; and to pick out the component with frequency 2ω(100 Hz) for measuring apparent power. The paper discusses what quantities are measured when the analyzer is set on certain definite values, and ponts out the optimum selection for various measurements.
基金supported by the Fundamental Research Funds for the Central Universities(WK3510000012 and WK3510000008)USTC Start-up Fund and National Natural Science Foundation of China(12004363)+6 种基金supported by the Swiss National Science Foundation(200021-188413)the SinoSwiss Science and Technology Cooperation(IZLCZ2-170075)supported via the UC Santa Barbara NSF Quantum Foundry funded via the Q-AMASE-i Program under award DMR-1906325the shared facilities of the NSF Materials Research Science and Engineering Center at UC Santa Barbara(DMR-1720256)supported by NSF CNS-1725797 and NSF DMR-1720256support from the California NanoSystems Institute through the Elings Fellowship programsupported by the National Science Foundation Graduate Research Fellowship Program(DGE-1650114)。
文摘Exotic quantum phenomena may appear in material systems with multiple orders or phases,where the mutual interactions can give rise to new physics beyond that of each component.Here,we report spectroscopic evidence for a unique combination of topology and correlation effects in the kagome superconductor CsV_(3)Sb_(5).Topologically nontrivial surface states are observed near the Fermi energy(E_(F)),indicating that the topological physics may be active upon entering the superconducting state.Flat bands are observed,suggesting that electron correlation effects are also at play in this system.Our results reveal the peculiar electronic structure of CsV_(3)Sb_(5),which holds the potential for realizing Majorana zero modes and anomalous superconducting states in kagome lattices.They also establish CsV_(3)Sb_(5)as a unique platform for exploring the interactions between the charge order,topology,correlation effects and superconductivity.
基金financial support from the Advanced Talents Incubation Program of Hebei University (521100221006)financial support from the National Natural Science Foundation of China (11974097)+2 种基金the Natural Science Foundation of Hebei Province (A2019201073)support from the National Natural Science Foundation of China (61875136)the Fundamental Research Project of Guangdong Province (2020A1515011315)
文摘Mechanoluminescent(ML)materials can directly convert external mechanical stimulation into light without the need for excitation from other forms of energy,such as light or electricity.This alluring characteristic makes ML materials potentially applicable in a wide range of areas,including dynamic imaging of force,advanced displays,information code,storage,and anti-counterfeiting encryption.However,current reproducible ML materials are restricted to sulfide-and oxide-based materials.In addition,most of the reported ML materials require pre-irradiation with ultraviolet(UV)lamps or other light sources,which seriously hinders their practical applications.Here,we report a novel ML material,MgF_(2):Mn^(2+),which emits bright red light under an external dynamic force without the need for pre-charging with UV light.The luminescence properties were systematically studied,and the piezophotonic application was demonstrated.More interestingly,unlike the well-known zinc sulfide ML complexes reported previously,a highly transparent ML film was successfully fabricated by incorporating MgF_(2):Mn^(2+)into polydimethylsiloxane(PDMS)matrices.This film is expected to find applications in advanced flexible optoelectronics such as integrated piezophotonics,artificial skin,athletic analytics in sports.
基金Supported by the Science Research&Train Program of(SRTP)Southeast University for Undergraduates
文摘We investigate theoretically the electron-reflection phenomenon in a graphene n＋n junction based on electron optics, where the local potential in the left n ＋ region is higher than that in the right n region. It is demonstrated numerically that electrons emitting from a point source in the n ＋ region will experience total internal reflection through the interface of the junction. The reflection becomes stronger and the transmission becomes weaker with decrease of the local potential in the right graphene ribbon. It is also found that when a nonideal interface is considered in the junction, the electron-reflection effect is enhanced due to interracial backseattering.
