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oe1(光电查) - 科学论文

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  • Storage systems for building-integrated photovoltaic (BIPV) and building-integrated photovoltaic/thermal (BIPVT) installations: Environmental profile and other aspects

    摘要: In recent years there has been an increasing interest in Building-Integrated Photovoltaic (BIPV) and Building-Integrated Photovoltaic/Thermal (BIPVT) systems since they produce clean energy and replace conventional building envelope materials. By taking into account that storage is a key factor in the effective use of renewable energy, the present article is an overview about storage systems which are appropriate for BIPV and BIPVT applications. The literature review shows that there are multiple storage solutions, based on different kinds of materials (batteries, Phase Change Material (PCM) components, etc.). In terms of BIPV and BIPVT with batteries or PCMs or water tanks as storage systems, most of the installations are non-concentrating, fa?ade- or roof-integrated, water- or air-based (in the case of BIPVT) and include silicon-based PV cells, lead-acid or lithium-ion batteries, paraffin- or salt-based PCMs. Regarding parameters that affect the environmental profile of storage systems, in the case of batteries critical factors such as material manufacturing, accidental release of electrolytes, inhalation toxicity, flammable elements, degradation and end-of-life management play a pivotal role. Regarding PCMs, there are some materials that are corrosive and present fire-safety issues as well as high toxicity in terms of human health and ecosystems. Concerning water storage tanks, based on certain studies about tanks with volumes of 300 L and 600 L, their impacts range from 5.9 to 11.7 GJprim and from 0.3 to 1.0 t CO2.eq. Finally, it should be noted that additional storage options such as Trombe walls, pebble beds and nanotechnologies are critically discussed. The contribution of the present article to the existing literature is associated with the fact that it presents a critical review about storage devices in the case of BIPV and BIPVT applications, by placing emphasis on the environmental profile of certain storage materials.

    关键词: ecotoxicity,Building-Integrated Photovoltaic/Thermal (BIPVT),embodied energy,Human toxicity,Life Cycle Assessment (LCA),CO2 emissions,Building-Integrated Photovoltaic (BIPV),Storage materials

    更新于2025-09-19 17:13:59

  • [IEEE 2019 6th International Conference on Image and Signal Processing and their Applications (ISPA) - Mostaganem, Algeria (2019.11.24-2019.11.25)] 2019 6th International Conference on Image and Signal Processing and their Applications (ISPA) - Enhanced Performance of Substrate Integrated Waveguide Bandstop Filter Based on Metamaterials SCSRRs

    摘要: High-frequency signals on interconnects can cause significant radiated electromagnetic emissions. An intermediate level modeling method aimed at providing a faster solution with less computing resources to allow designers to obtain rapid approximations is desirable. This paper presents a modeling technique to speed up the evaluation of radiated fields from interconnect cables. Based on the Hertzian dipole radiation theory and transmission-line frequency-dependant solutions, the radiating source is modeled by the sum of a large number of short dipoles. This model allows the contributions of line-end discontinuities to be included through a vector network analyzer measurement together with a monopole approximation. The proposed method is verified by open-line and RG 58 coaxial cable measurements.

    关键词: radiated electromagnetic emissions,Dipole radiation,transmission-line (TL) modeling,electromagnetic compatibility

    更新于2025-09-19 17:13:59

  • Novel efficient deep-red-emitting Ca2LuTaO6:Mn4+ double-perovskite phosphors for plant growth LEDs

    摘要: Deep-red-emitting phosphors are important for fabricating light-emitting diodes (LEDs) toward applications in plant growth lighting. Herein, we reported on novel efficient deep-red-emitting Mn4+-activated Ca2LuTaO6 (CLT) double-perovskite phosphors. A series of CLT:xMn4+ (x = 0.1, 0.2, 0.4, 0.6, 0.8, and 1.0 mol%) samples were prepared by the conventional high-temperature solid-state reaction technique, and they were characterized by using X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), elemental mapping, photoluminescence excitation and emission, decay curves, CIE chromaticity coordinates, internal quantum efficiency (IQE), and temperature-dependent emission spectra. The CLT host crystallized in a monoclinic structure with space group of P21/n, and it contained an octahedral site of TaO6 for Mn4+ doping. Impressively, under 351 ultraviolet light excitation these CLT:xMn4+ phosphors exhibited bright deep-red emissions around 682 nm with CIE chromaticity coordinates of (0.7272, 0.2728) and full width at half maximum (FWHM) of 25 nm. Notably, the optimal CLT:0.2%Mn4+ sample possessed an IQE of 37% and good resistance to thermal quenching (I423 K/I303K = 47%). Considering the emission spectrum of CLT:0.2%Mn4+ deep-red-emitting phosphors matched well with the absorption spectrum of phytochrome PFR, the as-prepared CLT:0.2%Mn4+ phosphors showed great potential in plant growth LEDs.

    关键词: Deep-red emissions,Phosphors,Luminescence,Double-perovskite,Mn4+,Plant growth lighting

    更新于2025-09-19 17:13:59

  • [IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Investigation of Accuracy of various STC Correction Procedures for I-V Characteristics of PV Modules Measured at Different Temperature and Irradiances

    摘要: Principal component analysis (PCA) and independent component analysis (ICA) for radiated emissions from printed circuits are critically intercompared, revealing similarities and differences of the extracted components between both methods. The input data in this analysis are measured wideband complex-valued magnetic radiated and evanescent fields with quasi-Gaussian spatial distributions. PCA and ICA lead to similar maps of their components when considered as spatial eigenmodes, but independent components exhibit simpler field structure than principal components.

    关键词: Independent component analysis (ICA),principal component analysis (PCA),radiated emissions,uncertainty quantification,stochastic fields

    更新于2025-09-19 17:13:59

  • CaOH Molecular Emissions in Underwater Laser-Induced Breakdown Spectroscopy: Spatial–Temporal Characteristics and Analytical Performances

    摘要: Recently, molecular emissions from the laser-induced plasma in ambient gas have gained increasing interest; however, very little is known about the case in water solutions. In this work, we investigated the spatiotemporal characteristics of molecular emissions, CaOH for instance, in underwater laser-induced breakdown spectroscopy (LIBS) by using time-resolved spectroscopy, spectral-resolved imaging, and shadowgraph techniques. It was shown that clear CaOH molecular bands can be observed in the spectrum at very early times after the laser pulse and presented a much longer lifetime and more homogeneous emission distribution compared with the Ca I and Ca II lines. Such unique characteristics of CaOH molecular emission inspired us to improve the performances of underwater LIBS by using the CaOH molecular bands instead of Ca I and Ca II lines. We demonstrated the excellent quanti?cation results of CaOH with higher stability, less self-absorption, and reduced matrix e?ect. Meanwhile, the limit of detection (LOD) of Ca with the CaOH molecular band (2.46 ppm) is comparable to that with the atomic line of Ca I (2.07 ppm), and much lower than that with the ionic line of Ca II (13.81 ppm), indicating a good sensitivity of CaOH. This work gives not only some insights into the molecule formation mechanisms in underwater plasmas, but also provides new ideas to improve the analytical performances of underwater LIBS.

    关键词: analytical performances,CaOH molecular emissions,underwater laser-induced breakdown spectroscopy,spatiotemporal characteristics

    更新于2025-09-19 17:13:59

  • Enhanced growth of Nd <sup>3+</sup> :MgGdB <sub/>5</sub> O <sub/>10</sub> laser crystals with intense multi-wavelength emission characteristics

    摘要: Higher quality Nd:GMB crystal was obtained using enhanced K2Mo3O10–B2O3 flux. Intense multi-wavelength emissions reveal the potential in THz technology.

    关键词: K2Mo3O10–B2O3 flux,Nd:GMB crystal,multi-wavelength emissions,THz technology

    更新于2025-09-19 17:13:59

  • Synthesis, energy transfer mechanism, and tunable emissions of novel Na3La(VO4)2:Re3+ (Re3+ = Dy3+, Eu3+, and Sm3+) vanadate phosphors for near-UV-excited white LEDs

    摘要: In this study, novel Eu3+-, Dy3+-, and Sm3+-activated Na3La(VO4)2 phosphors were synthesized using a solid state reaction method. X-ray diffraction analysis results indicated that the Na3La(VO4)2 phosphors had an orthorhombic crystal structure with the Pbc21 space group. There were two different La(1)O8 and La(2)O8 polyhedra with high asymmetry in the crystal structure. Scanning electron microscopy revealed that the product had a sheet morphology with an irregular particle size. Further, the luminescence properties, including the excitation and emission spectra, and luminescence decay curve, were investigated using a fluorescence spectrometer. The results showed that the Na3La(VO4)2 compound was an excellent host for activating the luminescence of Eu3+ (614 nm), Dy3+ (575 nm), and Sm3+ (647 nm) ions. Further, Dy3+/Eu3+ co-doped Na3La(VO4)2 phosphors were exploited, and the energy transfer from Dy3+ to Eu3+ was demonstrated in detail by the photoluminescence excitation, photoluminescence spectra, and luminescent decay curves. The results showed that the energy transfer efficiency from Dy3+ to Eu3+ was highly efficient, and the energy transfer mechanism was dipole–dipole interactions. Finally, tunable emissions from the yellow region of CIE (0.3925, 0.4243) to the red region of CIE (0.6345, 0.3354) could be realized by rationally controlling the Dy3+/Eu3+ concentration ratio. These phosphors may be promising materials for the development of solid-state lighting and display systems.

    关键词: Vanadate phosphor,White LED,Energy transfer,Lighting and display,Near ultraviolet excitation,Tunable emissions

    更新于2025-09-16 10:30:52

  • Impact of optimum power factor of PV-controlled inverter on the aging and cost-effectiveness of oil-filled transformer considering long-term characteristics

    摘要: The photovoltaic (PV) system is one of the most widespread of the renewable energy generation systems that are being used to meet the continuously increasing energy demand. A proposed analytical method is used to find the optimum power factor of PV inverter (PVI) that leads to minimum aging, reduced energy losses cost of the transformer, lower payback period of PV system, and lower green houses gases (GHG) emissions due to the transformer energy losses. In this study, the thermal performance of a 630?kVA mineral oil-filled transformer is simulated in MATLAB programming language. For an association, it is mandatory to connect a PV system to the grid to minimise the transformer loading. The PV output power is used to study the long-term impact of the solar irradiance on the transformer thermal performance. Also, the long-term climatic characteristics are considered. The ambient temperature surrounding the transformer is considered all day long. The load current profile was measured all day long. The results show the aging and cost-effectiveness of the transformer and the payback period of PV system and GHG emissions are a function of PVI power factor.

    关键词: transformer aging,PV inverter,photovoltaic system,power factor,cost-effectiveness,GHG emissions

    更新于2025-09-16 10:30:52

  • Feasibility and Cost Analysis of Photovoltaic-Biomass Hybrid Energy System in Off-Grid Areas of Bangladesh

    摘要: In this progressing technological advancement world, hybrid systems for power generation is one of the most promising fields for any researcher. In this context, photovoltaic-biomass hybrid systems with off-grid applications have become extremely popular with both Governments and individual users in rural areas of any part of the world. This system has gained popularity because of low cost, sustainability and very effective outcome with the use of natural resources at the rural areas. In this paper a proposed hybrid system which contains photovoltaics (PV) and biomass along with an additional storage has been considered to find the different aspects from an end user point of view. It also discusses the feasibility of the proposed model for an off-grid power system located in the remote areas of Ashuganj, Bangladesh. In order to analyse the pollutant emissions and calculate the cost parameters of the proposed system, RETScreen simulation software was deployed. This research also carries out a brief financial analysis considering the annual income of the end user and the payback periods for the installed system. It endeavours to provide complete information about different parameters which also includes the environmental impacts involved in establishing the proposed system. The conventional system in the pilot area is a kerosene-based system, hence in this research, a comparison between the proposed and the conventional system has been analysed using simulated results. The simple payback of the project was estimated to be 6.9 years and this model will be able to reduce the CO2 emissions by approximately 3.81 tonnes per year. The results have significantly supported the proposed system to be more reliable, environmentally-friendly and less costly than the conventional kerosene-based system.

    关键词: feasibility analysis,cost analysis,CO2 emissions,photovoltaics (PV),battery storage,renewable energy,simple payback period,biomass,off-grid electrification

    更新于2025-09-16 10:30:52

  • Reverse Manufacturing Enables Perovskite Photovoltaics to Reach the Carbon Footprint Limit of a Glass Substrate

    摘要: Innovative energy technologies with the lowest carbon footprint are needed. Our projections show that the photovoltaics (PVs) industry will have significant CO2 emissions in the transition away from fossil fuels. We demonstrate a reverse manufacturing concept for glass-solder-encapsulated, printed PV, based on in situ crystallization of emerging perovskite photo-absorbers. This concept reduces the CO2 emissions of PV 20-fold, approaching the ultimate lower limit of the glass substrate.

    关键词: Perovskite Photovoltaics,Carbon Footprint,Glass Substrate,CO2 Emissions,Reverse Manufacturing

    更新于2025-09-16 10:30:52