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A Novel Method of Auxiliary Power Supply Used in Wide-Range High Voltage Input DC-DC Converter
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作者 Jie Zhang Liangjie Li Cuicui Liu 《Energy and Power Engineering》 2017年第4期703-712,共10页
In high voltage input DC-DC converter, auxiliary winding of isolation transformer is usually used to supply power for control circuit. Due to the wide-range of input voltage, the variable output voltage of auxiliary w... In high voltage input DC-DC converter, auxiliary winding of isolation transformer is usually used to supply power for control circuit. Due to the wide-range of input voltage, the variable output voltage of auxiliary winding will cause a series of problems, such as variable drive pulse amplitude, increased driver switching devices loss and drive transformer core saturation. This paper analyzes the influence of variable output voltage of auxiliary winding in detail. A novel method is proposed to solve the problem of large variation range of auxiliary winding output voltage, which is adding a buck converter between the auxiliary winding and the control circuit. A dual switch forward convert has been designed with 300 V - 800 V input and 24 V/5 A output. The results show that this method is effective by comparing the different results of using buck converter or not. 展开更多
关键词 Dual Switch Forward CONVERTER wide-range INPUT AUXILIARY WINDING of Power Supply BUCK CONVERTER
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Wide-range optical sensors based on a single ring resonator with polarization multiplexing 被引量:1
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作者 岳永恒 朱慧慧 +2 位作者 曹紫葳 何建军 李明宇 《Chinese Optics Letters》 SCIE EI CAS CSCD 2019年第3期42-44,共3页
Wide-range optical sensors based on a single ring resonator are investigated theoretically and experimentally.The sensor worked at the TE and TM modes simultaneously. Because the sensitivities of the TE mode and TM mo... Wide-range optical sensors based on a single ring resonator are investigated theoretically and experimentally.The sensor worked at the TE and TM modes simultaneously. Because the sensitivities of the TE mode and TM mode are different, the TE mode is used for the large measurement range, and the TM mode is used for the high sensitivity measurement. The experimental results showed that the measurement range for the TE mode was almost three times larger than that of the TM mode. A sensitivity of 233 nm/RIU was achieved for the wavelength interrogation of the TM mode. 展开更多
关键词 wide-range optical sensors SINGLE RING RESONATOR POLARIZATION MULTIPLEXING
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Validation for equation of state in wide regime:Copper as prototype 被引量:5
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作者 Haifeng Liu Haifeng Song +2 位作者 Qili Zhang Gongmu Zhang Yanhong Zhao 《Matter and Radiation at Extremes》 SCIE EI CAS 2016年第2期123-131,共9页
In this paper we introduce the wide regime equation of state(WEOS)developed in Institute of Applied Physics and Computational Mathematics(IAPCM).A semi-empirical model of the WEOS is given by a thermodynamically compl... In this paper we introduce the wide regime equation of state(WEOS)developed in Institute of Applied Physics and Computational Mathematics(IAPCM).A semi-empirical model of the WEOS is given by a thermodynamically complete potential of the Helmholtz free energy which combines several theoretical models and has some adjustable parameters calibrated via some experimental and theoretical data.The validation methods of the equation of state in wide regime are presented using copper as a prototype.The results of the WEOS are well consistent with the available theoretical and experimental data,including ab initio cold curve under compression,isotherm,Hugoniot,off-Hugoniot and sound velocity data.It enhances our confidence in the accuracy of the WEOS,which is very important for the validation and verification of equation of state in high temperature and pressure technology. 展开更多
关键词 VALIDATION wide-range equation of state COPPER Ab initio cold curve Room-temperature isotherm HUGONIOT Velocity of sound
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Effects of structure and electronic properties of D-π-A organic dyes on photovoltaic performance of dye-sensitized solar cells 被引量:1
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作者 Min-Woo Lee Jae-Yup Kim +3 位作者 Hyung-Geun Lee Hyun Gil Cha Duck-Hyung Lee Min Jae Ko 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第3期208-216,共9页
Herein,we examine the performance of dye-sensitized solar cells containing five D-π-A organic dyes designed by systematic modification of π-bridge size and geometric structure.Each dye has a simple push-pull structu... Herein,we examine the performance of dye-sensitized solar cells containing five D-π-A organic dyes designed by systematic modification of π-bridge size and geometric structure.Each dye has a simple push-pull structure with a triarylamino group as an electron donor,bithiophene-4,4-dimethyl-4 H-cyclopenta 1,2-b:5,4-b’]dithiophene(M11),4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophenethiophene(M12),thiophene-4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophene(M13),4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophene-benzene(M14),and 4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophene(M15)units asπ-bridges,and cyanoacrylic acid as an electron acceptor/anchor.The extension of theπ-bridge linkage favors wide-range absorption but,because of the concomitant molecular volume increase,hinders the efficient adsorption of dyes on the TiO_(2) film surface.Hence,higher loadings are achieved for smaller dye molecules,resulting in(i)a shift of the TiO_(2) conduction band edge to more negative values,(ii)a greater photocurrent,and(iii)suppressed charge recombination between the photoanode and the redox couple in the electrolyte.Consequently,under one-sun equivalent illumination(AM 1.5 G,100 mW/cm^(2)),the highest photovoltage,photocurrent,and conversion efficiency(η=7.19%)are observed for M15,which has the smallest molecular volume among M series dyes. 展开更多
关键词 Dye-sensitized solar cells Donor-acceptor dyes Electron-rich unit wide-range absorption Impedance spectroscopy
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A low-diffusion robust flux splitting scheme towards wide-ranging Mach number flows 被引量:7
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作者 Shusheng CHEN Fangjie CAI +2 位作者 Xinghao XIANG Zhenghong GAO Chao YAN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2021年第5期628-641,共14页
This paper develops a low-diffusion robust flux splitting scheme termed TVAP to achieve the simulation of wide-ranging Mach number flows.Based on Toro-Vazquez splitting approach,the new scheme splits inviscid flux int... This paper develops a low-diffusion robust flux splitting scheme termed TVAP to achieve the simulation of wide-ranging Mach number flows.Based on Toro-Vazquez splitting approach,the new scheme splits inviscid flux into convective system and pressure system.This method introduces Mach number splitting function and numerical sound speed to evaluate advection system.Meanwhile,pressure diffusion term,pressure momentum flux,interface pressure and interface velocity are constructed to measure pressure system.Then,typical test problems are utilized to systematically assess the robustness and accuracy of the resulting scheme.Matrix stability analysis and a series of numerical cases,such as double shear-layer problem and hypersonic viscous flow over blunt cone,demonstrate that TVAP scheme achieves excellent low diffusion,shock stability,contact discontinuity and low-speed resolution,and is potentially a good candidate for wide-ranging Mach number flows. 展开更多
关键词 Computational Fluid Dynamics(CFD) Flux splitting ACCURACY ROBUSTNESS wide-ranging Mach number
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Digital logarithmic airborne gamma ray spectrometer 被引量:1
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作者 曾国强 张庆贤 +4 位作者 李晨 谭承君 葛良全 谷懿 程锋 《Chinese Physics C》 SCIE CAS CSCD 2014年第7期73-81,共9页
A new digital logarithmic airborne gamma ray spectrometer is designed in this study. The spectrometer adopts a high-speed and high-accuracy logarithmic amplifier (LOGll4) to amplify the pulse signal logarithmically ... A new digital logarithmic airborne gamma ray spectrometer is designed in this study. The spectrometer adopts a high-speed and high-accuracy logarithmic amplifier (LOGll4) to amplify the pulse signal logarithmically and to improve the utilization of the ADC dynamic range because the low-energy pulse signal has a larger gain than the high-energy pulse signal. After energy calibration, the spectrometer can clearly distinguish photopeaks at 239, 352, 583 and 609 keV in the low-energy spectral sections. The photopeak energy resolution of 137Cs improves to 6.75% from the original 7.8%. Furthermore, the energy resolution of three photopeaks, namely, K, U, and Th, is maintained, and the overall stability of the energy spectrum is increased through potassium peak spectrum stabilization. Thus, it is possible to effectively measure energy from 20 keV to 10 MeV. 展开更多
关键词 logarithmic amplifier airborne gamma ray spectrometer energy calibration wide-range spectrummeasurement cosmic rays measurement
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