This paper focuses on the problem of non-fragile guaranteed cost control for a class of T-S discrete-time fuzzy bilinear systems（DFBS）.Based on the parallel distributed compensation（PDC） approach,the sufficient co...This paper focuses on the problem of non-fragile guaranteed cost control for a class of T-S discrete-time fuzzy bilinear systems（DFBS）.Based on the parallel distributed compensation（PDC） approach,the sufficient conditions are derived such that the closed-loop system is asymptotically stable and the cost function value is no more than a certain upper bound in the presence of the additive controller gain perturbations.The non-fragile guaranteed cost controller can be obtained by solving a set of bilinear matrix inequalities（BMIs）.The Van de Vusse model is utilized to demonstrate the validity and effectiveness of the proposed approach.展开更多
We investigate the adiabatic enhanced compression of ultrashort pulses from a distributed feedback laser operated at 1550 nm in fibres with slowly decreasing dispersion (FSDD). High-quality pulse compressions from 4.4...We investigate the adiabatic enhanced compression of ultrashort pulses from a distributed feedback laser operated at 1550 nm in fibres with slowly decreasing dispersion (FSDD). High-quality pulse compressions from 4.4 ps down to 1.1ps in a l00m FSDD and from 4.4ps down to 830fs in a 500m FSDD are obtained. The Raman self frequency shift of femtosecond pulses in the compression is observed. Theoretical analyses are in good agreement with experimental results.展开更多
Optical loss spectra and refractive index changes have been measured in the hydrogenated standard telecommu-nication fiber and photosensitive fiber.The index changes due to ultraviolet exposure were found to be closel...Optical loss spectra and refractive index changes have been measured in the hydrogenated standard telecommu-nication fiber and photosensitive fiber.The index changes due to ultraviolet exposure were found to be closely related with the OH formation in both types of fibers.A direct photolyticd model is proposed to explain the effect of hydrogen loading on the enhancement of the photosensitivity in silica fibers.展开更多
A new blue thin film electroluminescence(TFEL)phosphor Gd_(3)Ga_(5)O_(12):Ag is prepared by electron beam evaporation.Photoluminescence and Electroluminescence of Gd_(3)Ga_(5)O_(12):Ag film were investigated.The lumin...A new blue thin film electroluminescence(TFEL)phosphor Gd_(3)Ga_(5)O_(12):Ag is prepared by electron beam evaporation.Photoluminescence and Electroluminescence of Gd_(3)Ga_(5)O_(12):Ag film were investigated.The luminance of TFEL device excited by an alternating-current sinusoidal voltage with frequency of 1000 Hz is about 2cd/m^(2).展开更多
Nitrogen reduction reaction(NRR)is an essential process for ammonia synthesis.Currently,such process is overwhelmingly catalyzed with iron-based metal catalysts and still confronts the big challenge of high overpotent...Nitrogen reduction reaction(NRR)is an essential process for ammonia synthesis.Currently,such process is overwhelmingly catalyzed with iron-based metal catalysts and still confronts the big challenge of high overpotential when room-temperature electrosynthesis is targeted due to the intrinsic inertness of NuN bond in N_(2).In this study,dual metal catalysts have been computationally designed and modulated by different non-metals dispersed in a graphene frame.As scanned by density functional theory(DFT)calculations,five candidates,namely Fe_(2)@SN_(4),Fe_(2)@BN_(4),Co_(2)@BN_(4),Co_(2)@PN_(4)and Ni_(2)@PN_(4)catalysts,have been identified as promising catalysts with a calculated onset potential of−0.20,−0.27,−0.36,−0.34,and−0.33 V,respectively;more importantly,the competitive hydrogen evolution reaction(HER)can be well suppressed during the NRR.Such excellent catalytic performance origins from two synergetic effects,including the metal–metal and metal–ligands(non-metals)interactions,both of which can promote the electron transfer from d-orbitals of metal atom pair to the anti-bonding orbitals of adsorbed N_(2)molecules.This can effectively activate the NuN bond,resulting in low NRR onset potential and high NH_(3)selectivity.The presented theoretical effort advances the theoretical understanding and provides guidance for the rational design of advanced non-precious NRR catalysts with high efficiency and selectivity.展开更多
基金supported by the National Natural Science Foundation of China(60374015)
文摘This paper focuses on the problem of non-fragile guaranteed cost control for a class of T-S discrete-time fuzzy bilinear systems（DFBS）.Based on the parallel distributed compensation（PDC） approach,the sufficient conditions are derived such that the closed-loop system is asymptotically stable and the cost function value is no more than a certain upper bound in the presence of the additive controller gain perturbations.The non-fragile guaranteed cost controller can be obtained by solving a set of bilinear matrix inequalities（BMIs）.The Van de Vusse model is utilized to demonstrate the validity and effectiveness of the proposed approach.
基金Supported by the Natural Science Foundation of the Guangdong Education Department(200019)the Natural Science Foundation of Guangdong Province(980030).
文摘We investigate the adiabatic enhanced compression of ultrashort pulses from a distributed feedback laser operated at 1550 nm in fibres with slowly decreasing dispersion (FSDD). High-quality pulse compressions from 4.4 ps down to 1.1ps in a l00m FSDD and from 4.4ps down to 830fs in a 500m FSDD are obtained. The Raman self frequency shift of femtosecond pulses in the compression is observed. Theoretical analyses are in good agreement with experimental results.
基金Supported by the National Natural Science Foundation of China under Grant No.69637050。
文摘Optical loss spectra and refractive index changes have been measured in the hydrogenated standard telecommu-nication fiber and photosensitive fiber.The index changes due to ultraviolet exposure were found to be closely related with the OH formation in both types of fibers.A direct photolyticd model is proposed to explain the effect of hydrogen loading on the enhancement of the photosensitivity in silica fibers.
基金Supported by Doctor Point Foundation under Grant No.97000401National“863 Program”of China under Grant No.715-0082Key Laboratory of Excited State Processes,Chinese Academy of Sciences.
文摘A new blue thin film electroluminescence(TFEL)phosphor Gd_(3)Ga_(5)O_(12):Ag is prepared by electron beam evaporation.Photoluminescence and Electroluminescence of Gd_(3)Ga_(5)O_(12):Ag film were investigated.The luminance of TFEL device excited by an alternating-current sinusoidal voltage with frequency of 1000 Hz is about 2cd/m^(2).
基金supported by the Natural Science Foundation of the Anhui Province(No.KJ2021A1171).
文摘Nitrogen reduction reaction(NRR)is an essential process for ammonia synthesis.Currently,such process is overwhelmingly catalyzed with iron-based metal catalysts and still confronts the big challenge of high overpotential when room-temperature electrosynthesis is targeted due to the intrinsic inertness of NuN bond in N_(2).In this study,dual metal catalysts have been computationally designed and modulated by different non-metals dispersed in a graphene frame.As scanned by density functional theory(DFT)calculations,five candidates,namely Fe_(2)@SN_(4),Fe_(2)@BN_(4),Co_(2)@BN_(4),Co_(2)@PN_(4)and Ni_(2)@PN_(4)catalysts,have been identified as promising catalysts with a calculated onset potential of−0.20,−0.27,−0.36,−0.34,and−0.33 V,respectively;more importantly,the competitive hydrogen evolution reaction(HER)can be well suppressed during the NRR.Such excellent catalytic performance origins from two synergetic effects,including the metal–metal and metal–ligands(non-metals)interactions,both of which can promote the electron transfer from d-orbitals of metal atom pair to the anti-bonding orbitals of adsorbed N_(2)molecules.This can effectively activate the NuN bond,resulting in low NRR onset potential and high NH_(3)selectivity.The presented theoretical effort advances the theoretical understanding and provides guidance for the rational design of advanced non-precious NRR catalysts with high efficiency and selectivity.
