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oe1(光电查) - 科学论文

380 条数据
?? 中文(中国)
  • Flexible but Mechanically Robust Hazy Quantum Dot/Glass Fiber Reinforced Film for Efficiently Luminescent Surface Light Source

    摘要: Color conversion films with haze have aroused interest for use in surface light sources for display and lighting applications. Surface patterning or addition of light scattering particles to the color-conversion film induces haze and consequently, improves the photoluminescence (PL) extraction. Herein, a CdSe/CdZnS quantum dots (QDs)-embedded glass fiber reinforced siloxane hybrid (QD-GFRH) film with high haze value is demonstrated, originating from refractive index mismatch between glass fiber and methacrylate-phenyl functionalized siloxane matrix. The hazy QD-GFRH film shows a twofold improvement in PL extraction, as well as robust mechanical properties, such as low thermal expansion (13 × 10?6 K?1) and high deformation resistance (E = 11.8 GPa), compared to conventional polymers. Because QDs are chemically dispersed inside the film by covalent crosslinking with siloxane matrix, the QD-GFRH film exhibits long-term (30 days) thermal and chemical stability against heat and moisture conditions [85 °C/5% relative humidity (RH), and 85 °C/85% RH]. Furthermore, the yellow photoemissive QD-GFRH film, with a smooth surface and large scale (A4 size, 210 mm × 297 mm size), is applied as a color-conversion film on a blue light-emitting diode and it covers a large color gamut (107% relative to National Television System Committee).

    关键词: light-converting films,quantum dots,haze control,thermomechanical properties,glass fiber reinforced films,surface light sources

    更新于2025-09-23 15:19:57

  • Single-step maskless nano-lithography on glass by femtosecond laser processing

    摘要: Femtosecond laser processing is widely adopted today for microfabrication because of its ability to make rapid processing on almost all types of materials in ambient environment. However, it is challenging to apply femtosecond lasers for high-speed large-scale subwavelength nanofabrication, particularly, for two-dimensional nanopatterning on transparent dielectric materials due to their low light absorption. Previous demonstrations of femtosecond laser two-dimensional nanofabrication on dielectrics typically lack structural quality and long-range uniformity. In this work, we report a maskless laser nano-lithographic technique to fabricate high-quality two-dimensional periodic nanodomes on glass. The glass sample is first coated with a thin copper film and then irradiated by femtosecond laser pulses. We show that the period and size of the nanodomes can be controlled using a multi-fluence process. More importantly, a single-fluence technique is developed here, for the first time, for high-quality nanopatterning on glass. The nanopatterning formation mechanism is studied by dynamics experiments and numerical simulations. This introduced technique will provide a simple but highly effective way for dielectrics nanofabrication.

    关键词: copper film,nanofabrication,nanodomes,femtosecond laser processing,glass

    更新于2025-09-23 15:19:57

  • Thermal characterization of a silicone-on-glass micro aspheric lens array for a concentrator photovoltaic module

    摘要: This study examined the effects of the thermal deformation of a silicone-on-glass (SOG) micro aspheric lens on the optical performance of a concentrator photovoltaic (CPV) module. Thermal deformation of the lens induced by temperature variation causes defocalization of the spot of concentrated light on the solar cell, resulting in a change in the optical efficiency and irradiance uniformity in the solar cell area. The irradiance uniformity affects the fill factor of the solar cell. The effects of the thermal deformation of the lens on the optical efficiency and irradiance uniformity in the solar cell area were evaluated through a three-dimensional thermal deformation simulation and ray-tracing simulation. The simulation methods were validated by indoor heating tests using a prototype SOG lens and III–V triple-junction solar cell. The simulation results for optical systems with geometric concentration ratios of 200 ? and 500 ? revealed that the temperature dependences of the optical performances of a system with SOG micro aspheric lenses showed similar trends to those of a system with SOG Fresnel lenses designed with the same lens surface profiles as aspheric lenses.

    关键词: Optical efficiency,Temperature dependence,Microscale concentrator photovoltaics,Plano-convex aspheric lens,Silicone-on-glass lens

    更新于2025-09-23 15:19:57

  • [IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Preliminary Study on Super Radiation-Resistant Mechanical-Stack Triple-Junction Space Solar Cell: PHOENIX

    摘要: Stained glass windows are designed to reveal their powerful artistry under diverse and time-varying lighting conditions; virtual relighting of stained glass, therefore, represents an exceptional tool for the appreciation of this age old art form. However, as opposed to most other artifacts, stained glass windows are extremely difficult if not impossible to analyze using controlled illumination because of their size and position. In this paper, we present novel methods built upon image based priors to perform virtual relighting of stained glass artwork by acquiring the actual light transport properties of a given artifact. In a preprocessing step, we build a material-dependent dictionary for light transport by studying the scattering properties of glass samples in a laboratory setup. We can now use the dictionary to recover a light transport matrix in two ways: under controlled illuminations the dictionary constitutes a sparsifying basis for a compressive sensing acquisition, while in the case of uncontrolled illuminations the dictionary is used to perform sparse regularization. The proposed basis preserves volume impurities and we show that the retrieved light transport matrix is heterogeneous, as in the case of real world objects. We present the rendering results of several stained glass artifacts, including the Rose Window of the Cathedral of Lausanne, digitized using the presented methods.

    关键词: light transport,recovery,dictionary learning,Banded matrices,stained glass,sparse cultural artifacts,computational relighting

    更新于2025-09-23 15:19:57

  • Examination of internal stress by photoelasticity in laser cleaving of glass

    摘要: Laser cleaving is a glass-cutting technique in which thermal stress induced by laser heating and cooling produces cracks in the glass. Stress measurement during the laser cleaving process is critical in elucidating the crack-propagation mechanism and solving the problems of the laser cleaving method. In this study, we measured the birefringence retardation using a high-speed polarization camera and evaluated the relevance and accuracy of the measured values by comparing them with the results of a numerical calculation. The birefringence retardation at the crack tip was also observed in the experimental process. For the experiment, a soda lime glass was cleaved using CO2 laser irradiation. Then, the birefringence retardation and azimuthal angle obtained using the polarization camera were compared with the numerical calculation results. The birefringence retardation around the crack tip corresponded with that of the deformation caused by mode I. The crack propagation was arrested when the crack tip approached the edge of the glass. The birefringence retardation observed using the polarization camera confirmed that the mode I deformation decreased as the crack approached the edge.

    关键词: Glass,Laser cleaving,Crack propagation,Numerical calculation,Photoelasticity

    更新于2025-09-23 15:19:57

  • Er3+,Yb3+-doped oxyfluorotellurite glassesa??Impact of temperature on spectroscopic properties and optical sensor qualities

    摘要: Oxyfluorotellurite glasses co-doped with erbium (0.5%) and ytterbium (2%, 5%) were manufactured from high purity reagents at 840 °C in air. Differential thermal analysis was used to estimate the temperatures of glass transition and glass crystallization of 2% and 5%Yb co-doped glasses. The effect of Yb3+ co-doping on relaxation dynamics of erbium excited states was demonstrated by the means of excitation, emission and fluorescence lifetime spectroscopy. Up-conversion luminescence spectra were studied in a function of temperature in the 295–675 K range, yielding information on thermal quenching of the emission and a temperature sensing model based on 2H11/2–4I15/2 to 4S3/2–4I15/2 erbium fluorescence intensity ratio. Application potential of the investigated material in optical sensor thermometry was evaluated. Maximum absolute and relative sensitivities were established at 6.45 × 10?3 K?1 at T = 675 K and 0.46 %K?1 at T = 400 K, respectively.

    关键词: Oxyfluorotellurite glass,(Er3+,Yb3+) Upconversion,Temperature sensor

    更新于2025-09-23 15:19:57

  • The influence of dust deposition on the temperature of soiling photovoltaic glass under lighting and windy conditions

    摘要: Module temperature has significant influence on the energy harvest and energy conversion efficiency of solar cells, which varies greatly with dust deposition and the wind-blowing. In this paper, several sets of experiments were carried out to test the temperature of soiling photovoltaic glass plate under lighting and windy conditions. The results indicate that the temperature of the upper and lower surface is much higher than that of the clean glass plate, and the dust deposition can exert great impact on the temperature of lower surface compared with that on the upper surface. At the same time, under the lighting and windy conditions, the maximum temperature of the photovoltaic glass plate decreases exponentially with increasing wind speed. The final temperature of clean glass plate tends to be consistent with the ambient one, while the temperature of dusty glass plate is much higher than air temperature. Through simulating the external electromagnetic field of spherical particle irradiated by the plane wave, we firstly found that the deposition particles can result in light convergence in its wavefront direction, and the light intensity can also be enhanced, significantly heating the glass plate. All our preliminary results throw light on the effect of dust deposition on the photovoltaic panel temperature in the desert, which can be helpful to establish a more reliable physical model of photovoltaic power generation efficiency involving environmental factors.

    关键词: Wind speed,Dust deposition,Photovoltaic glass,Temperature

    更新于2025-09-23 15:19:57

  • Crystallization and spectroscopic characterizations of binary SrO-B2O3 glasses doped with LiF, NaF, CaF2, or TiO2

    摘要: Glasses based on the basic chemical composition of binary strontium borate (SrO 50-B2O350 mol%) together with samples containing dopant (2%) with one of the fluorides (LiF, NaF, CaF2) or TiO2 have been synthesized through the routinely melting and annealing technique. Collective structural, optical, and thermal properties have been measured for the prepared glasses. X-ray diffraction and SEM measurements were carried out for their corresponding glass-ceramics which were synthesized by controlled thermal heat treatment with two-step regime. FT infrared absorption spectra reveal composite vibrational modes in the mid-range 400–1600 cm?1 which are related to the co-presence of both triangular and tetrahedral borate building units in their particular different wavenumber sites. The low dopant level did not make any distinct variations in the IR spectra. X-ray diffraction patterns elucidate the formed crystal phases after crystallization mainly strontium metaborate and other related borate phase and the LiF shows no distinct variation while NaF2 and CaF2 induce the formation of additional crystalline Na-containing or Ca-containing phases besides the formation of NaF or fluorite (CaF2). TiO2 acts as a nucleating agent and also separate as rutile. The crystallization behavior has been correlated with the assumption of the tendency of SrO to induce phase separation in the host binary borate glass and controlled heat treatment initiates the separation of strontium metaborate crystalline phase in the base binary SrO-B2O3 in accordance with its composition and the role of dopants is found to be varying with the type of dopant. The measured thermal expansion parameters of the prepared glasses reveal variations in their values for transformation and softening temperatures depending on the type of added dopant. The changes in the thermal expansion coefficients in the different parts of the thermal curves are related to the ability of the network to absorb lattice expansion through bending of the bonds. The uniform observed ultraviolet absorption bands are related to traces of iron (Fe3+) ions present as impurities.

    关键词: LiF,CaF2,NaF,Thermal expansion,FTIR optical spectra,SrO.B2O3 glass,Glass-ceramics,TiO2

    更新于2025-09-19 17:15:36

  • The Development of Accelerated Life Test Method of Multi-Layer Nano Thin Film Glass for Electric Automobiles

    摘要: According to expansion of electric automobiles, the multi-layer nano thin film glass with heating source is researched to retain safety driving for winter. Generally, the tungsten wire is used as a heating source of electric automobile glass. Due to its low visibility, silver (Ag) particles are researched for years. Ag is widely used as a material of heater in the automobile industry since it has relatively high heat and electrical conductivities. However, the multi-layer nano thin film glass using Ag particles is under development stage and is not verified in the field, so recall and claim can be raised. In this study, we will find the potential failure mechanism of the multi-layer nano thin film glass based on the properties, and then suggest accelerated life test method to verify 15 years in the automobile application.

    关键词: Electric automobiles,Multi-layer nano thin film glass,Accelerated life test,Windshield glass,Failure mechanism

    更新于2025-09-19 17:15:36

  • Sol-Gel Synthesis and Spectral Characterizations of (35-x)B2O3-65Bi2O3-x Fe2O3 Glass System

    摘要: Sol-gel technique was used to prepare glasses of the (35-x)B2O3-65Bi2O3-x Fe2O3 (0.1≤ x ≤ 0.4) system (A1-A4: x = 0.1, 0.2, 0.3, 0.4). The local structure and symmetry around trivalent iron were determined by studying X-band powder EPR spectra at room temperature. The EPR spectra of trivalent iron in glass samples are characterized by a more intense line at g = 4.2 and a less intense line at g = 2.0. The EPR line at g = 4.2 is attributed to trivalent iron in rhombic octahedral environment. The line at g = 2.0 is because of two or more trivalent iron coupling through dipole-dipole interactions in distorted octahedral symmetry. The intensity of EPR lines is dependent of Fe2O3 content in the glass samples. At higher concentration of Fe2O3, EPR line at g = 4.2 is less intense whereas the line at g = 2.0 is more intense which is ascribed to the formation of clusters of trivalent iron. The electronic spectra of glass samples show two broad bands corresponding to d-d transition in the range 410-450 nm and in the range 530-570 nm, respectively which are assigned to trivalent iron in distorted octahedral environment.

    关键词: Glass samples,Dipole-dipole interaction,Electronic spectra,Sol-gel technique

    更新于2025-09-19 17:15:36