- 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
-
Performance optimization of bi-layer solar steam generation system through tuning porosity of bottom layer
摘要： In recent years, solar steam generation has attracted many attentions due to its potential applications in desalination, etc. In the present work, a bi-layer solar steam generation system is prepared by daubing carbon particles on the sintered sawdust film, which possesses an advantage of adjustable porosities compared to widely used wood. Then, the influence of the porosity on the evaporation performance is explored. The experimental result indicates that: the porosity could significantly affect the water transportation in the film, and the water diffusivity increases almost linearly with the increase of the porosity. The evaporation efficiency increases with the increasing porosity, until the porosity reaches about 0.52 then decrease slowly. The positive effect of the increased water diffusivity and the negative effect of the increased thermal conductivity of the bottom film layer determine that the porosity of 0.52 is optimal for improving the evaporation efficiency. Under a solar light power of 1 kW·m?2, the optimal porosity gives an evaporation efficiency of 77.64%, which is comparable to the best performance of bi-layer systems reported in previous works. The conduction of heat through the bottom layer to the bulk water and the convection heat loss on the top surface contribute 83% to the total heat losses in the system, suggesting that the energy losses of these two modes should be further reduced in the future applications. Considering the accessible materials, easy preparation, low cost and high efficiency, we conclude that the 0.52-porosity system is suitable for being used as an efficient solar steam generation device.
关键词： Solar steam generation,Thermal conductivity,Solar energy,Porous material
更新于2025-11-14 15:14:40
-
Twins in YAl3(BO3)4 and K2Al2B2O7 Crystals as Revealed by Changes in Optical Activity
摘要： Many borate crystals feature nonlinear optical properties that allow for efficient frequency conversion of common lasers down into the ultraviolet spectrum. Twinning may degrade crystal quality and affect nonlinear optical properties, in particular if crystals are composed of twin domains with opposing polarities. Here, we use measurements of optical activity to demonstrate the existence of inversion twins within single crystals of YAl3(BO3)4 (YAB) and K2Al2B2O7 (KABO). We determine the optical rotatory dispersion of YAB and KABO throughout the visible spectrum using a spectrophotometer with rotatable polarizers. Space-resolved measurements of the optical rotation can be related to the twin structure and give estimates on the extent of twinning. The reported dispersion relations for the rotatory power of YAB and KABO may be used to assess crystal quality and to select twin-free specimens.
关键词： optical activity,inversion twin,YAB,optical rotatory dispersion,KABO,second harmonic generation,frequency conversion,K2Al2B2O7,NLO crystals,YAl3(BO3)4
更新于2025-10-22 19:40:53
-
Visible light active CZTS sensitized CdS/TiO2 tandem photoanode for highly efficient photoelectrochemical hydrogen generation
摘要： A tandem photoanode consisting of Cu2ZnSnS4 (CZTS) nanoparticles layer over CdS/TiO2 heterostructure thin film on FTO substrate has been fabricated for photoelectrochemical hydrogen generation. CdS thin film has been deposited by chemical bath deposition over the spin-coated TiO2 thin film, which is followed by the deposition of CZTS nanoparticles layer by spray coating technique resulting in a CZTS/CdS/TiO2/FTO photoanode. The coating of CZTS nanoparticles layer over CdS/TiO2 films resulted in the tandem structure of different band level positions, which enhances the optical absorption in the visible region and also leads to higher separation of the photogenerated charge carriers. A substantial enhancement (39 times) in the PEC activity has been demonstrated for the CZTS/CdS/TiO2/FTO photoanode as compared to TiO2/FTO photoanode, which is due to cascade band gap from 3.2 eV to 1.7 eV and formation of heterojunction at interfaces. The enhancement in the charge transport properties of CZTS/CdS/TiO2/FTO photoanode has been confirmed from the electrochemical impedance spectroscopy (EIS) measurement. The EIS results confirm that the CZTS/CdS/TiO2/FTO photoanode exhibited lowest charge transfer resistance (Rct = 302 Ω/cm2) as compared to CdS/TiO2 (Rct = 615 Ω/cm2) and TiO2 (Rct = 1700 Ω/cm2) photoanode. A mechanism depicting the enhanced the performance of photoelectrochemical (PEC) CZTS/CdS/TiO2/FTO photoanode has been proposed.
关键词： EIS,Hydrothermal,PEC,Hydrogen generation,CZTS nanoparticles
更新于2025-10-22 19:40:53
-
PV-pumped energy storage option for convalescing performance of hydroelectric station under declining precipitation trend
摘要： The precipitation trend is critically important for functioning of hydroelectric power stations and development of irrigation sector. Studies indicate that freshwater availability in many river basins in India is likely to decrease due to climate change. Despite having promising hydro potential in north-eastern (N-E) region of India, decline in rainfall in the region causes paucity of water in various hydro power plants' reservoirs. Many units of hydroelectric projects are being kept off and as a result, generation comes down to a large extent. As a partial solution to the problem, many such small hydroelectric projects' may be revived by integrating solar photovoltaic (PV) powered pumped storage unit as there is synergy of solar energy with irrigation water pumping and hydro power station. The present study aims to looking at reliable, continuous and cost-competitive power supply option. The study has been conceived with the lone hydroelectric power station of Tripura (one of the N-E states of India) which practically remains inoperative as water is hardly available at the end of the year and before next monsoon. Results substantiate that PV powered pumped storage is a viable option for restoring the steady annual performance of the hydroelectric plant.
关键词： PV power generation,Pumped storage,Generation mix,Hydro power generation,Climate change
更新于2025-09-23 15:23:52
-
[IEEE 2017 4th International Conference on Opto-Electronics and Applied Optics (Optronix) - Kolkata (2017.11.2-2017.11.3)] 2017 4th International Conference on Opto-Electronics and Applied Optics (Optronix) - A noble approach to light the path trail using swarm technology
摘要： Swarm intelligence (Intro SI) is the collective behaviour of decentralized, self-organized systems, natural or artificial. It is many minds working together. It is the first step in allowing people to pool their knowledge and insights into a single elevated intelligence. The objective is to light on a path trail by the leading robot, so that the rest of the robots could follow the trail to work as a unified system, thereby reducing time and manpower.
关键词： adaptive path exploration,swarm intelligence,Robot sensing systems,cognitive map generation,neighbouring robots,path trail information
更新于2025-09-23 15:23:52
-
[IEEE 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC) - Waikoloa Village, HI, USA (2018.6.10-2018.6.15)] 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC) - Commercial Test of Anti-Reflective Coating on First Solar Cadmium Telluride PV Modules
摘要： Anti-reflective coatings (ARC) are commonly applied to photovoltaic (PV) modules in the solar industry to increase power and energy output. In addition to characterization of initial module power and angle of incidence modifier (IAM), it is important to verify that the expected gain is observed in commercial system operation. This analysis shows the increased performance of ARC First Solar CdTe PV modules compared to non-ARC equivalent modules in a commercial test in New South Wales, Australia. PPI analysis indicates a sustained ARC performance gain over time, suggesting good ARC durability. Detailed actual-expected analysis shows both array types performing at or above expected levels after almost 2 years in the field. ARC arrays show slightly greater benefit than predicted compared to non-ARC arrays.
关键词： CdTe thin film photovoltaics,solar power generation,performance analysis,photovoltaic systems,PV anti-reflective coatings,solar energy
更新于2025-09-23 15:23:52
-
Photonic generation of high-purity 60?GHz millimeter-wave signal requiring only 10?GHz radio frequency local oscillator
摘要： A novel approach to generate 60 GHz millimeter-wave from a 10 GHz radio frequency signal using an integrated nested DD-MZM without optical filter is proposed and demonstrated. The simulation results show that the generated frequency sextupling optical mm-wave has high purity with an OSSR exceeding 29 dB and a RFSSR of 25 dB, which is consistent with the theoretical analysis. Besides, a RoF link model is established to investigate the transmission performance. The eye diagram keeps clear even when the optical mm-wave is transmitted over 60 km and the power penalty is about 0.4 dB after fiber transmission of 50 km.
关键词： Optical fiber communication,Dual-drive Mach–Zehnder modulator (DD-MZM),Optical millimeter-wave generation
更新于2025-09-23 15:23:52
-
Ultraviolet treatment restores bioactivity of titanium mesh plate degraded by contact with medical gloves
摘要： Titanium mesh plate (Ti mesh) used for bone augmentation inadvertently comes into contact with medical gloves during trimming and bending. We tested the hypotheses that glove contact degrades the biological capability of Ti mesh and that ultraviolet treatment (UV) can restore this capability. Three groups of Ti mesh specimens were prepared: as-received (AR), after glove contact (GC), and after glove contact followed by UV treatment. The AR and GC meshes were hydrophobic, but GC mesh was more hydrophobic. AR and GC meshes had significant amounts of surface carbon, and Si content was higher for GC mesh than for AR mesh. UV mesh was hydrophilic, and carbon and silicon content values were significantly lower in this group than in the AR and GC groups. The number, alkaline phosphatase activity, and mineralization ability of attached osteoblasts were significantly lower in the GC group than in the AR group and markedly higher in the UV group than in the AR group. In conclusion, glove contact caused chemical contamination of Ti mesh, which significantly reduced its bioactivity. UV treatment restored bioactivity in contaminated Ti mesh, which outperformed even the baseline Ti mesh.
关键词： photofunctionalization,osteoblasts,titanium mesh,guided bone generation
更新于2025-09-23 15:23:52
-
A highly efficient fluorescent material based on rare-earth-modified polyhydroxyalkanoates
摘要： Fluorescent materials play an important role in biomedical fields. However, the main types of fluorescent materials suffer from several disadvantages especially the biotoxicity, which largely restrict its wider applications in biological fields. In this study, a highly efficient rare-earth-modified fluorescent material was successfully designed and fabricated based on polyhydroxyalkanoates, which are known as biodegradable and biocompatible material. A new Functional-PHA polymer was microbially synthesized by engineered Halomonas bluephagenesis and was used as a basal matrix to generate the rare-earth-modified PHA. N-acetyl-L-cysteine-grafted PHA (NAL-grafted-PHA) was first produced via a UV-initiated thiol-ene click reaction and the rare earth metal ions (Eu3+ and Tb3+) were subsequently chelated onto the NAL-grafted-PHA through the coordination effect. The composite material exhibited intense photoluminescence properties under UV laser excitation, indicating the excellent features as fluorescent material. The enhanced hydrophilicity and superior biocompatibility of rare earth-chelated PHA were confirmed, suggesting its great potential application value in biomedical fields.
关键词： Halomonas,photoluminescence,next generation industrial biotechnology,fluorescent material,polyhydroxyalkanoates,PHB,Rare-earth metal ions
更新于2025-09-23 15:23:52
-
Fabrication of bilayered attapulgite for solar steam generation with high conversion efficiency
摘要： Solar steam generation has been attracting wide attention for boosting the evolution of solar-energy-harvesting technology. Here, we demonstrate the fabrication of a novel bilayer photothermal material based on attapulgite/poly acrylamide composite (APAC), which was prepared by the solution polymerization of acrylamide (AM) in the presence of attapulgite using N, N’ - Methylene bisacrylamide (MBA) as a crosslinker, for efficient solar steam generation. The APAC shows better thermal stability with a decomposition temperature of 250 oC, good mechanical property with a compress strength of up to 125 KPa at 75% strain and a low apparent density (0.0191 g·cm-3) with abundant porosity accompanying with a low thermal conductivity (0.07 W m-1 K-1). To enhance the light absorption of APAC, a thin carbon layer was created on the surface of APAC via a facile flame treatment. Under our conditions, the bilayered APAC shows a high vapor rate of 1.2 kg m-2 h-1 under 1 sun illumination, equal to 85% solar-to-vapor efficiency. With the merits of cost-efficient, scalable manufacture, high solar energy conversion efficiency, the APAC may hold the great potential as high-performance photothermal materials for solar energy generation.
关键词： conversion efficiency,Solar steam generation,attapulgite,bilayer
更新于2025-09-23 15:23:52