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Near-field radiative heat transfer enhancement by multilayers and gratings in the thermophotovoltaic system

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Science China(Technological Sciences) 2023年第10期66卷 2968-2977页

作者： XU ZhiGuo HU ZhiFang School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

The near-field effect can be used to improve the output power of the near-field thermophotovoltaic device(NTPV).The nearfield radiative heat transfer in the near-field thermophotovoltaic device can be enhanced by the excitation of hyperbolic modes and the coupling of surface plasmon *** this study,we design a two-body near-field thermophotovoltaic system based on hyperbolic *** multilayer structure on the emitter is composed of Ga-doped ZnO(GZO)and hafnium dioxide(HfO2).The gratings are on the InAs photovoltaic *** electrodynamics and rigorous coupled-wave method are employed to calculate radiative heat *** is found that the NTPV system with multiple microstructures performs better than the NTPV system just with single *** NTPV system performs better in a wider vacuum *** output power and efficiency are enhanced by the GZO-HfO2surface plasmon polaritons in multilayer *** gratings can monitor the spectral heat flux to match the cell band gap to enhance the performance of the near-field thermophotovoltaic *** investigation provides a novel approach for improving the output power of a two-body near-field thermophotovoltaic system.

关键词： near-field radiative heat transfer thermophotovoltaics multilayer surface plasmon polariton output power

Nonlinear energy harvesting with dual resonant zones based on rotating system

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Applied Mathematics and Mechanics(English Edition) 2021年第2期42卷 275-290页

作者： Dan WANG Zhifeng HAO Fangqi CHEN Yushu CHEN School of Mathematical Sciences University of JinanJinan 250022China College of Aerospace Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China School of Astronautics Harbin Institute of TechnologyHarbin 150001China

An electromagnetic nonlinear energy harvester(NEH)based on a rotating system is proposed,of which the host system rotates at a constant speed and vibrates harmonically in the vertical *** kind of device exhibits several resonant phenomena due to the combinations of the rotating and the vibration frequencies of the host system as well as the cubic nonlinearity of the *** governing equation of motion for the NEH is derived,and the dynamic responses and output power are investigated with the multiple scale method under the 1:1 primary and 2:1 superharmonic resonant *** effects of system parameters including the nondimensional external frequency,the rotating speed,and the nonlinear stiffness on the responses of free vibration for the system are *** results of the primary resonance show that the responses exhibit not only the resonant characteristics but also the nonlinear dynamic characteristics such as the saddle-node(SN)*** coexistence of multiple solutions and the varying trends of responses are verified with the direct numerical ***,the effects of system parameters on the average output power are *** results of the analyses on the two resonant conditions indicate that the large power can be harvested in two resonant frequency *** effect of resonance on the output power is dominant for the 2:1 superharmonic ***,the results also show that introducing the nonlinearity can increase the value of the output power in large frequency bands and induce the occurence of new frequency bands to harvest the large *** efficiency of the harvested power could be improved by the combined effects of the resonance as well as the nonlinearity of the NEH *** parameter conditions could help optimize the power harvesting in design.

关键词： nonlinear energy harvester(NEH) resonance output power multiple scale method rotating system

Triboelectric nanogenerators with a constant inherent capacitance design

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Nano Research 2023年第3期16卷 4077-4084页

作者： Lanyue Gan Fan Xia Panpan Zhang Xijun Jiang Yuxuan Liu Simiao Niu Youfan Hu Hunan Institute of Advanced Sensing and Information Technology Xiangtan UniversityXiangtan 411102China Key Laboratory for the Physics and Chemistry of Nanodevices Center for Carbon-Based ElectronicsAcademy for Advanced Interdisciplinary StudiesSchool of ElectronicsPeking UniversityBeijing 100871China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Department of Biomedical Engineering Rutgers UniversityPiscatawayNJ 08854USA

Triboelectric nanogenerators(TENGs)utilize the phenomena of contact electrification and electrostatic induction to harvest mechanical energy from the environment.A good match between the motion frequency and the circuit characteristic frequency is critical for the effective power generation of a ***,most TENGs have a time-dependent inherent capacitance(TICTENG),which hinders an optimal design for efficient energy ***,we propose a novel structure of a TENG with a constant inherent capacitance(CIC-TENG)and a mathematical model is established to provide analytical expressions of key output parameters of the device,which gives numerical simulation results that are in good agreement with the experimentally obtained *** of merit and an optimization strategy are also given as guidelines for the optimization of material selection,geometry design,***,a disk-formed CIC-TENG(DCIC-TENG)with polarity-switched triboelectric pairs is constructed to harvest unidirectional mechanical energy continuously,achieving an output power density of 55 mW/m^(2).The effects of the motion frequency,the number of electrodes and triboelectric pairs on the charge transfer efficiency of the DCICTENG are assessed and a preferred design strategy is ***,the CIC-TENG demonstrates approximately two-fold advantages in power transfer efficiency over the TIC-TENG,and a DCIC-TENG-based self-powered anemometer was fabricated to measure wind speed in real time.

关键词： triboelectric nanogenerator inherent capacitance output power linearity

Modeling, Experimental Study on the Heat Transfer Characteristics of Thermoelectric Generator

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Journal of Thermal Science 2013年第1期22卷 48-54页

作者： Ze-Guang Zhou Dong-Sheng Zhu Hong-Xia Wu Hong-Sheng Zhang School of Chemistry and Chemical Engineering South China University of Technology

This paper investigates the heat transfer characteristics of a thermoelectric generator. The influence of heat dissipation intensity to the sub-thermal resistances distribution is experimentally studied. Based on the thermal network analysis and finite time thermodynamics, an analytical model including all thermal resistances (in both thermocouples and external heat exchangers) is developed to predict the performance of the generator. The results show that the computed values of output power agree well with the experimental values. The heat transfer enhancement on the generator cold side greatly reduces the cold side temperature and thermal resistance, and obviously improves the output power. Compare with air natural convection cooling, the main thermal resistance changes from the resistance between the fins and the ambient to the thermal contact resistances between the generator and the heat sink at the conditions of forced convection and water cooling. This study may be guide the optimization of generator structure.

关键词： thermoelectric generator thermal network thermal resistance analytical model heat transfercharacteristic output power

Consecutive induction melting of nickel-based superalloy in electrode induction gas atomization

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Chinese Physics B 2017年第6期26卷 1-7页

作者：峰山夏敏葛昌纯 School of Materials Science and Engineering University of Science and Technology Beijing (USTB) Beijing 100083 China

The crucible-free electrode induction melting gas atomization（EIGA） technology is an advanced technology for preparing ultra-clean nickel-based superalloy powders. One of the key issues for fabricating powders with high quality and yield is the consecutive induction melting of a superalloy electrode. The coupling of a superalloy electrode and coil,frequency, output power, and heat conduction are investigated to improve the controllable electrode induction melting process. Numerical simulation results show that when the coil frequency is 400 kHz, the output power is 100 kW, superalloy liquid flow with a diameter of about 5 mm is not consecutive. When the coil frequency is reduced to 40 kHz, the output power is 120 kW, superalloy liquid flow is consecutive, and its diameter is about 7 mm.

关键词： electrode induction gas atomization coil frequency output power thermal conduction

Efficient Diode-Pumped Passively Q-Switched Nd-GdVO4 Lasers

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Chinese Physics Letters 2002年第12期19卷 1808-1810页

作者： LIU Jie JIA Yu-Lei YANG Ji-Min DU Juan HE Jing-Liang Laboratory of Modern Optics Shandong Normal University

An efficient diode-pumped Nd:GdVO4 laser passively Q-switched by a Cr4+:YAG as an saturable absorber was developed. A KTP crystal is used for the extra-cavity second-harmonic generation (SHG) and a BBO crystal for the sum frequency mixing (SFM). The green output power is 172 mW at incident pump power of 8 W. The ultraviolet (UV) output power is measured to be 20 mW at the same pump power. The peak power of UV laser is 143 W with the pulse repetition rate of 14 kHz and pulse width of 10 ns.

关键词： PULSE REPETITION RATE power Saturable absorbers ultraviolet laser light maximum loads sum frequency power Second-harmonic generation power PULSE WIDTH Pumps output power power (Psychology) Ultraviolet Rays Energy sources

Compact Diode-Pumped Continuous-Wave Nd：LuVO4 Lasers Operated at 916 nm and 458 nm

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Chinese Physics Letters 2006年第5期23卷 1192-1194页

作者：张玲张春雨魏志义张驰龙拥兵张治国张怀金王继扬 Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 National Laboratory of Crystal Materials and Institute of Crystal Materials Shandong University Jinan 250100

We report the compact diode-pumped continuous-wave （CW） Nd：LuV04 lasers operated at 916nm and 458nm for the first time. The maximum output power of 780mW at 916nm laser is obtained with a slope efficiency of 9.3%. ... 详细信息

关键词： FREQUENCY-DOUBLED ND output power YAG LASER PERFORMANCE EFFICIENT CRYSTAL

Improvement of 1.3-μm GaInNAs Vertical Cavity Surface Emitting Lasers Grown by MOVPE

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Chinese Physics Letters 2004年第1期21卷 81-83页

作者：岳爱文沈坤石兢王任凡 DepartmentofPhysics WuhanUniversityWuhan430072 WuhanTelecommunicationDevicesCo. Wuhan430074 InternationalCenterforMaterialPhysics ChineseAcademyofSciencesShenyang110016

We report the improved performance of the conventional contact 1.3 μm GaInNAs vertical cavity surface emitting lasers (VCSELs) grown by metal-organic vapour-phase epitaxy (MOVPE). A new wet etching approach was applied in the fabrication of 1.3 μm GaInNAs oxide-confined VCSELs. The threshold current of single mode device is 1.0 mA. The multiple mode devices show very low threshold currents below 2 mA at 5-85 ℃, which were the best results for 1.3 μm GaInNAs VCSELs reported. Maximum single mode output power of 0.256mW and the maximum multiple mode power of 0.883 mW were obtained at room temperature.

关键词： fabrication threshold currents single-mode output power Vertical cavity surface emitting lasers Metalorganic vapor phase epitaxy

Core Size Scaling of Helical-Core Optical Fibres

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Chinese Physics Letters 2006年第10期23卷 2793-2795页

作者：赵楚军范滇元彭润伍唐志祥叶云霞 Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800

The mode-area scaling properties of helical-core optical fibres are numerically studied and the limit of core size for achievable single-mode operation is explored. By appropriate design, helical-core fibres can opera... 详细信息

关键词： SINGLE-MODE OPERATION output power LASER AMPLIFIER