This paper presents a method for reliability evaluation of a hybrid generation system of wind and tidal powers with battery energy storage.Such a system may widely exist in coastal areas and islands in the future.A ch...This paper presents a method for reliability evaluation of a hybrid generation system of wind and tidal powers with battery energy storage.Such a system may widely exist in coastal areas and islands in the future.A chronological multiple state probability model of tidal power generation system(TPGS)considering both forced outage rate(FOR)of the TPGS and random nature of tidal current speed is developed.In the evaluation of FORs of TPGS and WPGS(wind power generation system),the delivered power related failure rates of power electronic converters for TPGS and WPGS are considered.A chronological power output model of battery energy storage system(BESS)is derived.A hybrid system of tidal and wind generation powers with a BESS is used to demonstrate the effectiveness of the presented method.In case studies,the effects of various parameters on the system reliability are investigated.展开更多
'Giant' Cd Se/Cd S core/shell nanocrystals(NCs) were synthesized with thick Cd S shell(15 monolayers), and the x-ray diffraction(XRD) measurement indicates there is a zinc blende phase in the thick Cd S shell,...'Giant' Cd Se/Cd S core/shell nanocrystals(NCs) were synthesized with thick Cd S shell(15 monolayers), and the x-ray diffraction(XRD) measurement indicates there is a zinc blende phase in the thick Cd S shell, whereas it transformed into wurtzite phase under 5 min radiation with a 400 nm, 594 μJ∕cm2femtosecond(fs) laser beam.The evolution of the NCs’ spontaneous emission under the fs laser radiation was recorded with a Hamamatsu streak camera. The as-synthesized NCs exhibit an amplified spontaneous emission(ASE) at 530 nm, which comes from a bulk-like Cd S shell due to the interfacial potential barrier, which could slow down the relaxation of holes from the shell to the core. After being annealed by an fs laser, the ASE of the g-NCs is transferred from a bulk-like Cd S shell to a quantum-confined Cd Se core because the phase transformation determined with the XRD measurement could remove the interfacial barrier. Besides the ASE at 643 nm, two shorter-wavelength ASE peaks at 589 and 541 nm, corresponding to optical transitions of the second(1P) and third(1D) electron quantization shells of the Cd Se core, also appear, thus indicating that Auger recombination is effectively suppressed.展开更多
酞毒(Pc ) 的一个 chiral 识别过程的分子水平的鉴定被扫描通道显微镜学(STM ) 在 Cu (100 ) 表面上学习。STM 表明一个 chiral Pc 分子与另外的 Pc 分子形成一系列亚稳的更暗淡的配置。最后, Pc 分子与一样的 chirality 认出另一个 Pc...酞毒(Pc ) 的一个 chiral 识别过程的分子水平的鉴定被扫描通道显微镜学(STM ) 在 Cu (100 ) 表面上学习。STM 表明一个 chiral Pc 分子与另外的 Pc 分子形成一系列亚稳的更暗淡的配置。最后, Pc 分子与一样的 chirality 认出另一个 Pc 分子形成一种稳定的更暗淡的配置。Homochiral dimers 在 Cu 表面上被发现,表明 Pc dimerization 的 chiral 特性。为这个 chiral 识别过程的机制被识别,揭示 Cu 表面上的 chiral dimers 的特别吸附几何学的关键角色。展开更多
The radial contraction-expansion motion paradigm is a novel steady-state visual evoked experimental paradigm,and the electroencephalography(EEG)evoked potential is different from the traditional luminance modulation p...The radial contraction-expansion motion paradigm is a novel steady-state visual evoked experimental paradigm,and the electroencephalography(EEG)evoked potential is different from the traditional luminance modulation paradigm.The signal energy is concentrated chiefly in the fundamental frequency,while the higher harmonic power is lower.Therefore,the conventional steady-state visual evoked potential recognition algorithms optimizing multiple harmonic response components,such as the extended canonical correlation analysis(eCCA)and task-related component analysis(TRCA)algorithm,have poor recognition performance under the radial contraction-expansion motion paradigm.This paper proposes an extended binary subband canonical correlation analysis(eBSCCA)algorithm for the radial contraction-expansion motion paradigm.For the radial contraction-expansion motion paradigm,binary subband filtering was used to optimize the weighting coefficients of different frequency response signals,thereby improving the recognition performance of EEG signals.The results of offline experiments involving 13 subjects showed that the eBSCCA algorithm exhibits a better performance than the eCCA and TRCA algorithms under the stimulation of the radial contraction-expansion motion paradigm.In the online experiment,the average recognition accuracy of 13 subjects was 88.68%±6.33%,and the average information transmission rate(ITR)was 158.77±43.67 bits/min,which proved that the algorithm had good recognition effect signals evoked by the radial contraction-expansion motion paradigm.展开更多
基金supported in part by the National “111” Project of China under Grant B08036China State Grid Science and Technology Project(SGCQDK00DJJS1500056)
文摘This paper presents a method for reliability evaluation of a hybrid generation system of wind and tidal powers with battery energy storage.Such a system may widely exist in coastal areas and islands in the future.A chronological multiple state probability model of tidal power generation system(TPGS)considering both forced outage rate(FOR)of the TPGS and random nature of tidal current speed is developed.In the evaluation of FORs of TPGS and WPGS(wind power generation system),the delivered power related failure rates of power electronic converters for TPGS and WPGS are considered.A chronological power output model of battery energy storage system(BESS)is derived.A hybrid system of tidal and wind generation powers with a BESS is used to demonstrate the effectiveness of the presented method.In case studies,the effects of various parameters on the system reliability are investigated.
基金supported by the National Basic Research Program of China (973 Program, 2012CB921801)the Science and Technology Department of Jiang Su Province (BE2012163)the Scientific Research Foundation of Graduate School of Southeast University (YBJJ1443)
文摘'Giant' Cd Se/Cd S core/shell nanocrystals(NCs) were synthesized with thick Cd S shell(15 monolayers), and the x-ray diffraction(XRD) measurement indicates there is a zinc blende phase in the thick Cd S shell, whereas it transformed into wurtzite phase under 5 min radiation with a 400 nm, 594 μJ∕cm2femtosecond(fs) laser beam.The evolution of the NCs’ spontaneous emission under the fs laser radiation was recorded with a Hamamatsu streak camera. The as-synthesized NCs exhibit an amplified spontaneous emission(ASE) at 530 nm, which comes from a bulk-like Cd S shell due to the interfacial potential barrier, which could slow down the relaxation of holes from the shell to the core. After being annealed by an fs laser, the ASE of the g-NCs is transferred from a bulk-like Cd S shell to a quantum-confined Cd Se core because the phase transformation determined with the XRD measurement could remove the interfacial barrier. Besides the ASE at 643 nm, two shorter-wavelength ASE peaks at 589 and 541 nm, corresponding to optical transitions of the second(1P) and third(1D) electron quantization shells of the Cd Se core, also appear, thus indicating that Auger recombination is effectively suppressed.
基金Acknowledgements This work was supported by the National Basic Research Program of China (No. 2013CB934200) and the National Natural Science Foundation of China (Nos. 10979015 and 50976048). L. W. acknowledges the financial support from the Program for New Century Excellent Talents in University, Ministry of Education of the People's Republic of China (No. NECT-11-1003) and Jiangxi Provincial "Ganpo Talents 555 Projects". M. D. D. acknowledges financial support from the Danish National Research Foundation, the Carlsberg Foundation, and the Villum Foundation.
文摘酞毒(Pc ) 的一个 chiral 识别过程的分子水平的鉴定被扫描通道显微镜学(STM ) 在 Cu (100 ) 表面上学习。STM 表明一个 chiral Pc 分子与另外的 Pc 分子形成一系列亚稳的更暗淡的配置。最后, Pc 分子与一样的 chirality 认出另一个 Pc 分子形成一种稳定的更暗淡的配置。Homochiral dimers 在 Cu 表面上被发现,表明 Pc dimerization 的 chiral 特性。为这个 chiral 识别过程的机制被识别,揭示 Cu 表面上的 chiral dimers 的特别吸附几何学的关键角色。
基金This work is granted by National Natural Science Foundation of China(Grant Nos.62006024,62071057)the Fundamental Research Funds for the Central Universities(BUPT Project No.2019XD17)Aeronautical Science Foundation of China(NO.2019ZG073001).
文摘The radial contraction-expansion motion paradigm is a novel steady-state visual evoked experimental paradigm,and the electroencephalography(EEG)evoked potential is different from the traditional luminance modulation paradigm.The signal energy is concentrated chiefly in the fundamental frequency,while the higher harmonic power is lower.Therefore,the conventional steady-state visual evoked potential recognition algorithms optimizing multiple harmonic response components,such as the extended canonical correlation analysis(eCCA)and task-related component analysis(TRCA)algorithm,have poor recognition performance under the radial contraction-expansion motion paradigm.This paper proposes an extended binary subband canonical correlation analysis(eBSCCA)algorithm for the radial contraction-expansion motion paradigm.For the radial contraction-expansion motion paradigm,binary subband filtering was used to optimize the weighting coefficients of different frequency response signals,thereby improving the recognition performance of EEG signals.The results of offline experiments involving 13 subjects showed that the eBSCCA algorithm exhibits a better performance than the eCCA and TRCA algorithms under the stimulation of the radial contraction-expansion motion paradigm.In the online experiment,the average recognition accuracy of 13 subjects was 88.68%±6.33%,and the average information transmission rate(ITR)was 158.77±43.67 bits/min,which proved that the algorithm had good recognition effect signals evoked by the radial contraction-expansion motion paradigm.