We have comparatively investigated electrically pumped random lasing (RL) actions of two metal-insulator-semiconductor structured devices using pure ZnO and Zn2TiO4-nanoparticle-incorporated ZnO films as the semiconductor components i.e. light-emitting layers, respectively. It is demonstrated that the device using the Zn2TiO4-nanoparticle-incorporated ZnO film as the light-emitting layer exhibits a much smaller threshold current for the electrically pumped RL, which is ascribed to the enhanced multiple light scattering by incorporation of Zn2TiO4 nanoparticles into ZnO film. It is believed that this work provides a strategy for developing low-threshold ZnO-based random lasers.
Regionally distributed energy supply system is not only an important energy Internet physical carrier, but also the prototype and foundation of energy Internet. It focuses on physical technologies such as collaborative optimization between different energy sources. Distributed energy supply system has important research significance for exploring the internal operation mechanism of promoting advanced energy technology and different energy sources. In view of the special position of regionally distributed energy supply system in the transformation of energy system, it is particularly important to realize the scientific and reasonable coordinated operation and optimal dispatching of multiple energy in regionally distributed energy supply system, meet the demand for cooling and heating and power, and maximize the comprehensive economic benefits such as emission reduction and energy conservation. The coordinated operation and optimal scheduling of energy supply equipment in regionally distributed energy supply system is the core technology to ensure the safe, stable and economic operation of distributed energy supply system. Comprehensively considering the complex coupling characteristics of thermoelectricity and the random characteristics of renewable energy and load, coordinating the multi-directional energy flow in distributed energy supply system, studying the optimal operation mode of distributed energy supply system and optimal scheduling strategy will be the key research direction of energy Internet in the future. Based on the conventional cogeneration system, renewable energy generation is introduced. Firstly, the coupling interaction characteristics of photovoltaic power generation systems, wind power and other random power sources in the regionally distributed energy supply system and cogeneration system are considered, and the steady-state model is constructed. Then, combining the characteristics of operation of external energy supply conditions and energy supply equipment, The typical operation modes and power flow calculation methods of regionally distributed energy supply system are analyzed and combed. Relevant research will promote the efficient and intelligent development of regionally distributed energy supply system technology and improve the practicability of distributed energy supply system technology. Further improve the performance of using distributed energy technology to adapt to the dynamic characteristics of large-scale renewable energy access system. Make full use of the advantages of renewable energy green power generation to greatly reduce fossil energy emissions, save energy and reduce consumption, and reduce environmental pollution.
Abstract The 2.8A to 6.6A power supply method is widely used in Airfield Groud Lighting (AGL) system at present. This power supply method is formulated based on the luminous characteristics of halogen lamps. Although The LED light fixtures significantly reduce the energy consumption of the lamps, the energy-saving effect for the entire AGL system is not ideal, mainly due to the high current of the power supply circuit and the high loss of the circuit itself. Through the classification of low-current AGL system, this article proposes a low-current implementation method suitable for China’s civil aviation. For low-current AGL system, which cannot meet existing civil aviation industry standards and specifications in China’s civil airports, through analyzing the differences between low-current AGL system and existing 6.6A power supply systems in design requirements, implementation and construction, operation and maintenance, as well as existing technical specifications, Propose low Specific requirements for the application of current-assisted AGL system, and propose energy-saving retrofit technical solutions based on the characteristics of AGL projects, laying the foundation for the application of low-current AGL system in Chinese civil airports.
The effect of single junction GaAs solar cells irradiated by 808nm, 1070nm and 10.6um CW lasers is investigated. The results show that, as long as under the same laser coupling intensity, the damage modes of solar cells under different irradiation conditions are similar. With the increase of laser coupling intensity, the maximum temperature of solar cells rises, and the maximum power of solar cells shows a 'stair-step' decline. The multiple irradiation experiments of triple junction GaAs solar cells by 1070nm CW laser are carried out. The results show that when the laser intensity is more than 12.8W/cm2 , the performance degradation of solar cells will show a significant accumulation effect. In addition, the thermal sensitive damage factors are explored and verified. The results show that the maximum temperature and the duration of high temperature are sensitive factors for laser irradiation damage of solar cells.
Abstract Because of low measurement redundancy and frequent switch changes, it is difficult to identify the correct topology structure. In this paper, a topology recognition method of distribution network based on branch active power is proposed. Firstly, branch active power residual algorithm is used to identify the topological structure. The topology obtained by this method has the highest matching degree with the real-time measured data. Then genetic algorithm is used to optimize the inverse recognition of power grid topology. The numerical example shows that the method is reasonable, effective, rapid and simple. It also has good adaptability with a large number of measurement errors.
Download This Paper Open PDF in Browser Add Paper to My Library Share: Permalink Using these links will ensure access to this page indefinitely Copy URL Copy DOI
We report on remarkable decrease in threshold current for electrically pumped random lasing (RL) from the light-emitting device based on two-fold-tandem (double-) SiO2/ZnO-structure with respect to that in the case of single-SiO2/ZnO-structured device. Moreover, the former is of higher power conversion efficiency. In the double-SiO2/ZnO-structure, a waveguide is formed by the stacking SiO2/ZnO/SiO2, which enables photon confinement. Moreover, the electrons leaking out of the bottom SiO2/ZnO-structure are collected and partly involved in the radiative recombination in the top one. Furthermore, the RL photons generated in the bottom SiO2/ZnO-structure act as the stimuli to increase the stimulated emission rate in the top one. For the above-mentioned reasons, the RL performance of the double-SiO2/ZnO-structured device is substantially improved.
Cobalt-bridged organometallic molecular wires (p-Co-p, p-Co-m and m-Co-m) are synthesized, and their charge transport properties are studied. The experimental results show that the quantum interference (QI) effects of cobalt-bridged organometallic wires are determined by the anchoring group. Interestingly, the cobalt-bridge reduces the conductance of the junctions and tunes the QI effect of the wires. These results demonstrate the unique property of metal-bridged organometallic molecular wires and their potential applications in molecular electronics.
Amorphous germanium (a-Ge) films in the thickness range of 5.2–370.7 nm were prepared by radio frequency magnetron sputtering. Spectroscopic ellipsometry analysis shows that less than 3% of medium-range order exists in a-Ge under the reported deposition conditions.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)