- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2019
- photovoltaic power generation system
- sensitivity analysis
- Monte Carlo
- fuzzy layering evaluation method
- Electrical Engineering and Automation
- Xi’an Jiaotong University
-
Simulated performance analysis of a solar aided power generation plant in fuel saving operation mode
摘要： Solar aided (coal-fired) power generation (SAPG) system has been proved to be an efficient way to utilize the solar energy for power generation. Due to the instability of the solar radiation, a SAPG system generally operates under transient working conditions. In this paper, performance simulation sub-models of main components in a SAPG plant are established based on the lumped parameter assumption. A 330 MW SAPG power plant as a case study is simulated. The variations of the performances, main parameters of the plant with the solar field heat output and the dynamic responses under a typical day are analyzed. The results show that when the heat output of the solar field changes from 0 kJ/h to 2.13 × 108 kJ/h, the coal saving rate will increase to 6.4%, and the solar power generation share (the proportion of the power from the solar energy to the total power from the SAPG plant) will increase to 7.74%. During the analysis process, in order to optimize the solar field, the concept of the solar field equivalent efficiency (SFEE) is proposed and the optimal velocity of heat transfer fluid (HTF) in absorber tube is obtained.
关键词： Optimize design,Dynamic responses,Solar aided coal-fired power generation,Parameter variation
更新于2025-09-23 15:21:21
-
Pb <sub/>2</sub> GaF <sub/>2</sub> (SeO <sub/>3</sub> ) <sub/>2</sub> Cl: Band Engineering Strategy by Aliovalent Substitution for Enlarging Bandgap while Keeping Strong Second Harmonic Generation Response
摘要： Wide bandgap and strong second-order generation (SHG) effect are two crucial but contradictory conditions for practical nonlinear optical (NLO) materials. Herein, a new NLO crystal Pb2GaF2(SeO3)2Cl (I) containing novel functional (GaO3F3)6? octahedra is designed and synthesized by a rational band engineering strategy with aliovalent substitution. Benefiting from the removal of transition metal cations and the introduction of bridged F anions, I exhibits the widest bandgap among all reported phase-matchable NLO selenites. Meanwhile, a strong SHG response more than 4.5 times of KH2PO4 (KDP) is maintained. The dominate role of the (GaO3F3)6? groups to the enlarged bandgap in I are elucidated by first-principles studies.
关键词： aliovalent substitution,second harmonic generation,nonlinear optical materials,selenites,band engineering
更新于2025-09-23 15:21:21
-
Attosecond pulse generation via multicolor beam superposition in the over-barrier ionization regime
摘要： Based on coherent superposition of multicolor continuous wave beams, high order harmonics and attosecond pulse generation from a hydrogen molecular ion (HMI), +H ,2 with different internuclear distances, R, are studied. Driving pulse intensity was taken to be 400 TW cm?2, which can ionize an +H2 ion with R?>?Rb?=?2.4 a.u. over the barrier. It is seen that cutoff harmonic with respect to R decreases until the over barrier ionization threshold, Rb, then becomes almost uniform to the end of R?=?10 a.u. whereas it is almost constant with respect to the spectral width of the beams, Δω. Besides attosecond pulse intensity increases versus R, and decreases with respect to Δω so that the most intense attosecond pulses can be generated from HMIs with R???5 a.u. via the pulses by Δω???0.03 a.u. Attosecond pulse durations were insensitive to both Δω and R.
关键词： hydrogen ion molecule,high order harmonic generation,H2,attosecond
更新于2025-09-23 15:21:21
-
Coherent Tabletop EUV Ptychography of Nanopatterns
摘要： Coherent diffraction imaging (CDI) or lensless X-ray microscopy has become of great interest for high spatial resolution imaging of, e.g., nanostructures and biological specimens. There is no optics required in between an object and a detector, because the object can be fully recovered from its far-field diffraction pattern with an iterative phase retrieval algorithm. Hence, in principle, a sub-wavelength spatial resolution could be achieved in a high-numerical aperture configuration. With the advances of ultrafast laser technology, high photon flux tabletop Extreme Ultraviolet (EUV) sources based on the high-order harmonic generation (HHG) have become available to small-scale laboratories. In this study, we report on a newly established high photon flux and highly monochromatic 30 nm HHG beamline. Furthermore, we applied ptychography, a scanning CDI version, to probe a nearly periodic nanopattern with the tabletop EUV source. A wide-field view of about 15 × 15 μm was probed with a 2.5 μm?diameter illumination beam at 30 nm. From a set of hundreds of far-field diffraction patterns recorded for different adjacent positions of the object, both the object and the illumination beams were successfully reconstructed with the extended ptychographical iterative engine. By investigating the phase retrieval transfer function, a diffraction-limited resolution of reconstruction of about 32 nm is obtained.
关键词： high-order harmonic generation,ptychography,lensless X-ray microscopy,Extreme Ultraviolet,Coherent diffraction imaging
更新于2025-09-23 15:21:21
-
[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Seven Years of Tandem-X: Volume Loss of Grosser Aletschgletscher, Switzerland
摘要： Grosser Aletschgletscher, the largest glacier in the European Alps, contains 20% of the entire Swiss ice mass. However, mass balance simulations based on current climate models predict 90% mass loss by 2100. The glacier is a super-test site for the TanDEM-X satellite mission and data series starting from 2011 are available. In this study we analyzed almost 100 digital elevation models computed from bistatic radar interferograms and compare the derived height loss with model predictions. Additionally, we used patch-based offset tracking to determine a new velocity map of the complete glacier. The results show that the current height loss of 3.3 meters per year is close to that mass balance simulation which uses the ensemble median of common European climate models which predict, relative to 1999, a warming of 4.3?C by 2100.
关键词： offset tracking,radar interferometry,DEM generation,mass balance,Aletsch Glacier,ice velocity
更新于2025-09-23 15:21:21
-
Quantification of Vortex Generation Due to Non-Equilibrium Electrokinetics at the Micro/Nanochannel Interface: Spectral Analysis
摘要： We report on our investigation of a low Reynolds number non-equilibrium electrokinetic ?ow in a micro/nanochannel platform. Non-equilibrium electrokinetic phenomena include so-called concentration polarization in a moderate electric ?eld and vortex formation in a high electric ?eld. We conducted a spectral analysis of non-equilibrium electrokinetic vortices at a micro/nanochannel interface. We found that periodic vortices are formed while the frequency varies with the applied voltages and solution concentrations. At a frequency as high as 60 Hz, vortex generation was obtained with the strongest electric ?eld and the lowest concentration. The power spectra show increasing frequency with increasing voltage or decreasing concentration. We expect that our spectral analysis results will be useful for micromixer developers in the micromachine research ?eld.
关键词： spectral analysis,concentration polarization,micromixer,Vortex generation,electrokinetics,micro/nanochannel
更新于2025-09-23 15:21:21
-
Oxygen-Defected Molybdenum Oxides Hierarchical Nanostructure Constructed by Atomic-Level Thickness Nanosheets as an Efficient Absorber for Solar Steam Generation
摘要： Solar steam generation is a potential approach for fresh water recycling, thus attracting increasing attention recently. To further promote water evaporation rate, some new materials need to be developed, such as plasmonic transition metal oxides. In this work, we report an oxygen-defected molybdenum oxides hierarchical nanostructure (MoOx HNS) composed of ultrathin nanosheets with atomic-level thickness, which is demonstrated as an efficient absorber for solar steam generation. Benefiting from broadband light absorption and special assembled architecture, the resulting MoOx HNS loaded on a PTFE membrane (MoOx HNS Membrane) exhibits excellent performance for boosting steam generation rate. Under 1 sun (1 kW m?2) illumination, the evaporation rate can reach at 1.255 kg m?2 h?1, with the energy conversion efficiency of 85.6%, which is one of the best performance compared with other desalination materials. Meanwhile, the MoOx HNS Membrane can achieve high-performance seawater desalination in both laboratorial and outdoor conditions. The enhanced water evaporation performance can be attributed to the synergistic effects of the efficient solar-to-thermal conversion and the unique channel structure. This work expands the scope of investigated materials which can be applied in seawater desalination system.
关键词： MoOx hierarchical nanostructure,seawater desalination,photothermal conversion,oxygen vacancies,solar steam generation
更新于2025-09-23 15:21:21
-
Some structural, linear and nonlinear optical characteristics of single KDP crystals influenced by EDTA additive
摘要： Single Potassium Dihydrogen Phosphates (KDP) crystals were successfully grown in pure and 1 mol% Ethylenediaminetetraacetic acid disodium salt (EDTA) added KDP solutions by Sankaranarayanan–Ramasamy method. Their growth was oriented in type I phase-matching direction which is one of two conditions of maximum second harmonic generation efficiency. The elemental compositions of the crystals were determined by EDX analysis. The UV–Vis spectroscopy, FT-IR analysis, X-Ray diffraction, and second harmonic generation studies have been carried out in order to assess the influence of EDTA additive on quality of KDP crystal. EDTA can improve the structural perfection and optical characteristics of the crystal. Especially, this additive helps increase second harmonic generation efficiency of KDP crystal, which is very useful for frequency doublers.
关键词： Second harmonic generation,EDTA,KDP,Nonlinear optics,SR method
更新于2025-09-23 15:21:21
-
Technological development of multi-energy complementary system based on solar PVs and MGT
摘要： The complementary micro-energy network system consisting of solar photovoltaic power generation (solar PVs) and micro-gas turbine (MGT), which not only improves the absorption rate and reliability of photovoltaic power, but also has the advantages of low emission, high efficiency, and good fuel adaptability, has become one of the most promising distributed power systems in the field of micro grid. According to the development of current technology and the demand of actual work, this research described the domestic and foreign development of micro-energy network system based on solar PVs and MGT. Moreover, it analyzed the challenges and future development regarding the micro-energy network system in planning and design, energy utilization optimization and dispatching management, and system maintenance, respectively. Furthermore, it predicted the future development of the key technology of the multi-energy complementary system. These results will be beneficial for the progress of this field both in theory and practice.
关键词： solar photovoltaic power generation,micro gas turbine,micro-energy network,multi-energy complementary system,renewable energy
更新于2025-09-23 15:21:21
-
Facile synthesis approach for core-shell TiO2–CdS nanoparticles for enhanced photocatalytic H2 generation from water
摘要： With the ambition to design a cost-effective and highly stable photocatalyst with improved photocatalytic activity towards H2 generation by water splitting, herein we report a two-step facile synthesis approach for core-shell structure of TiO2-CdS nanocomposites. The synthesized photocatalysts are comprehensively characterized by SEM, XRD, BET, UV-vis DRS, Photoluminescence and XPS to investigate the morphological, crystalline, structural, optical properties and surface analysis. The photocatalytic activity is evaluated by measuring the ability of TiO2-CdS to generate H2 gas by water splitting in the presence of hole scavengers under simulated solar light at AM 1.5G conditions. Our optimized sample TiO2-CdS (3:2) exhibited an enhanced photocatalytic activity by generating 954 μmol g-1 h-1 of hydrogen which is ~1.4 and ~1.7 times higher than pure CdS nanoparticles and pure TiO2, respectively. The optimized sample achieved an apparent quantum efficiency of 3.53% along with good stability by generating a similar amount of H2 for 40 consecutive hours. The enhanced photocatalytic activity and stability of the core-shell TiO2-CdS nanocomposite is attributed to the broader solar spectrum absorption, efficient photo-induced charge separation on the interface of TiO2-CdS due to the formation of heterojunction and high surface area with a large fraction of mesopores.
关键词： Photocatalytic H2 generation,Core-Shell TiO2-CdS nanocomposite,hydrothermal approach,CdS nanoparticles,Heterojunction
更新于2025-09-23 15:21:21