- 标题
- 摘要
- 关键词
- 实验方案
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12.2: A 3D Display Parallel System: Light Field Re-rendering and Depth Sense Optimization
摘要： The main benefit of 3D display over 2D display is the obvious ability to create a more lifelike character with high depth sense. However, the limitation of human eye’s visual mechanism, unartful 3D scene structure design, or bad viewing condition always emerges poor depth perception experience or even physiological discomfort during the watching time, which is often sub-optimal for mass high-quality 3D display productions. To solve this problem, we propose a novel 3D display parallel system for depth sense optimization and it empirically guides how the light field should be re-rendered. Structurally, the parallel system consists of an artificial perception measurement system, a display evaluation model and a light field display rendering system, which includes the display calibration, scene capture, light field data processing and display. Particularly, the system can systematically analyze and model various factors affecting the depth sense which learned through the measurement system, like scene structure, objects’ speeds in 3D video and so on. And those sense factors can be personally modified or increased according to the viewer’s demands or technical improvement. Moreover, the light field could be real-time re-rendered, based on some image processing technology, optical flow analysis and object segmentation (or tracking) (especially the one-shot video segmentation). Theory and algorithms are developed and experimental validation results show a superior performance.
关键词： Light Field Re-rendering,Depth Sense,3D Video Processing,One-shot Segmentation,3D Display Parallel System
更新于2025-09-09 09:28:46
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Photocarcinogenesis & Photoprotection || Role of Photodynamic Therapy in Cancer Treatment
摘要： Cancer is one of the most fatal diseases next only to cardiovascular diseases spread all around the globe, and it is the third most fatal disease in India. Environmental factors such as chemicals, UV light, tobacco products, X-rays, viruses, and disturbance in oncogenes are the factors which induce mutations that are inheritable and result in cancer. PDT comprises of three essential components: photosensitizer (PS), light, and oxygen. Oxygen in the form of reactive oxygen species can be toxic and may lead to cell death via necrosis or apoptosis. PDT is a two-stage procedure. Administration of a light-sensitive PS is followed by irradiation of tumor loci with a light of appropriate wavelength. This chapter describes about oncogenes and role of photodynamic therapy in treatment of oncogenes.
关键词： Cancer and light,Photosensitizer,Oncogenes,Photodynamic therapy
更新于2025-09-09 09:28:46
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Novel photocatalyst nitrogen-doped simonkolleite Zn5(OH)8Cl2·H2O with vis-up-conversion photoluminescence and effective visible-light photocatalysis
摘要： As photocatalysts exhibit selectivity toward various pollutants, it is necessary to develop different and novel photocatalysts. In this work, a novel photocatalyst-nitrogen-doped simonkolleite Zn5(OH)8Cl2·H2O (DSM) is prepared through a new facile method: calcinating the mixture of zinc hydroxide, urea, and guanidine hydrochloride at 575?°C for 1?h in a furnace with an air atmosphere. The as-prepared sample was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectra, UV–visble near-infrared diffuse reflection spectra (UV–Vis–NIR DRS), Brunauer–Emmett–Teller (BET) method, Ramen spectra and Zeta potential measurement, photocatalytic properties, as well as active species trapping experiments. XRD and XPS show the as-prepared powder is nitrogen-doped simonkolleite Zn5(OH)8Cl2H2O (DSM) with a small ZnCl2 fraction. SEM investigation indicates that the as-prepared powder possesses a flower-like layered shape. The UV–Vis–NIR exhibits that after doping, the DSM possesses strong light absorption in the ranges of 300–500 and 1400–2500?nm, a direct electronic transition with a band gap energy of 2.469?eV. PL measurement reveals a strong photoluminescence and an up-conversion from lower to higher-energy visible light in as-prepared samples. Zeta potential investigations show that during photocatalysis, the charges on as-prepared photocatalyst are positive. The photocatalytic experiments show a good dark adsorption, a high photodegradation (99.4% at 60?min), a high pseudo-first-order constant (k) of 0.0261?min?1. Meanwhile, the active species trapping experiments suggest that hole (h+) is the dominant active species during photocatalysis. It is concluded that the doping favors in enhancing vis-light-photocatalysis. This work makes a significant contribution to the literature.
关键词： photocatalyst,nitrogen-doped simonkolleite,visible-light photocatalysis,photoluminescence
更新于2025-09-09 09:28:46
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Measuring Complex for the Diagnostics of the Quality of Light–Emitting Heterostructures According to Photoelectric and Optical Responses Under Local Photoexcitation
摘要： We propose an automated measuring complex for the diagnostics of the lateral homogeneity of semiconductor heterostructures by measurements and analysis of the photoelectric and optic responses to their local photoexcitation in static and dynamic modes. The electronic-mechanical and optical positioning systems guarantee the illumination of local region of the investigated structure with a minimum diameter of the spot of 14 μm and a positioning accuracy of 10 μm. It is shown that the measuring complex can be used for the diagnostics of the quality of light-emitting heterostructures, transistors, solar cells, and photodiodes.
关键词： local photoexcitation,light-emitting heterostructures,photoelectric response,quality diagnostics,lateral heterogeneity,automated installation
更新于2025-09-09 09:28:46
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Optimization of the liquid–liquid interfacial precipitation method for the synthesis of $$\hbox {C}_{60}$$C60 nanotubes
摘要： Tubular fullerene nanowhiskers called ‘fullerene nanotubes’ are composed of C60 fullerene molecules (C60 NTs) are synthesized at room temperature using the liquid–liquid interfacial precipitation method in the pyridine and isopropyl alcohol (IPA) system. The growth control of fullerene nanotubes is important for their chemical and physical properties as well as for their future applications. In the present study, we investigated the effect of light, water, solvent ratio and temperature on the synthesis of C60 nanotubes. A marked development in the yield of C60 NTs was achieved using dehydrated solvents, a solution with a volume ratio of 1:9 for pyridine: IPA, a growth temperature equal to 5?C and by illuminating the C60-pyridine solution with ultraviolet light (wavelength 302 nm) for 102 h. The synthesized fullerene nanotubes were characterized by different analytical techniques including Raman and Fourier transform infrared spectroscopy, optical microscopy, focussed ion beam scanning electron microscopy and transmission electron microscopy.
关键词： solution growth,liquid–liquid interfacial precipitation method,light,temperature,solvent,Fullerene nanotubes
更新于2025-09-09 09:28:46
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Degradation study of malachite green on chitosan films containing heterojunctions of melon/TiO2 absorbing visible-light in solid-gas interfaces
摘要： Urea modified TiO2 nanoparticles were synthesized at different TiO2: urea ratios (10, 30 and 60 (%wt) named UTiO2-10, 30 and 60) by sol-gel method and annealing at 400 °C during 1h. Characterization revealed the presence of TiO2 nanoparticles with visible light absorption (between 400 and 500 nm) probably due by the formation of thermolysis urea byproducts such as melon, which may induce a TiO2/melon heterojunction. Then, modified nanoparticles were immobilized on chitosan films by adding 30% (70QS/30UTiO2) and 50% 50QS/50UTiO2) of UTiO2 nanoparticles. Functionalized films were characterized by SEM-EDS, DRS and AFM. Photo-induced degradation of malachite green stains was evaluated on these films under different wavelengths. Upon UV-A+visible light irradiation, films showed good activity even slightly better than those containing Evonik P-25 (70QS/30P-25). Upon visible light between 450 and 800 nm, films evidenced a satisfactory performance but slower than under UV-A+visible light irradiation whereas the photobleaching activity of 70QS/30P-25 was very poor. When visible light irradiation with wavelengths higher than 590 nm was used, a slight photobleaching was also observed. DRS spectra taken at different irradiation times showed that dye underwent N-demethylated oxidative reactions either upon UV-Visible or visible light irradiation. ATR-FTIR measurements revealed the generation of benzophenones after 6 h of irradiation probably suggesting the formation of singlet oxygen under visible light. 70QS/30UTiO2-10 films showed a good photo-bleaching activity after 18 h of continuous UV-A+visible light irradiation.
关键词： urea,Visible-light responsive TiO2,chitosan films,melon/TiO2 heterojunction
更新于2025-09-09 09:28:46
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Interfacial influence on electrical injection and transport characterization of CoFeB|MgO|GaAs-InGaAs quantum wells hetero-structure
摘要： The quality of interfaces is a key factor for efficient electrical spin injection into quantum well light emitting diodes. Here, we investigate the interfacial influence on the electrical transport properties in CoFeB|MgO|GaAs-InGaAs quantum wells hetero-structure, by considering textured MgO tunnel barrier fabricated by two different techniques: sputtering and molecular beam epitaxy (MBE). From forward and reverse current–voltage characteristics, it is found that the threshold voltage decreases as the annealing temperature changes from room temperature to 300°C for sputtered samples, however there is not much difference in threshold voltage with the annealing temperature for MBE-grown samples. In combination with transmission electron microscope (TEM) studies, it is found the MgO|GaAs interface by MBE is sharp for both grown and annealed states. However, there is a thin (~0.4 nm) amorphous MgO layer at the MgO|GaAs interface for sputtered samples with grown state, and the amorphous MgO can be improved and crystallized after annealing. The MgO|GaAs interface plays a role in modulating the band structure and has an influence on electrical injection. Our work demonstrated that CoFeB|MgO|GaAs interfaces are important and can be engineered thanks to the use of two types of growth for the textured MgO tunnel barriers, which ensures efficient electrical injection.
关键词： Spin light emitting diode,Structural and electrical properties,MIS structure,Interfacial states
更新于2025-09-09 09:28:46
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Enhanced visible-light photocatalytic activity of ZnS/BiOBr/graphene oxide ternary composite
摘要： In this paper, a facile and highly efficient ternary composite ZnS/BiOBr/Graphene oxide (ZnS/BiOBr/GO) with zinc vacancies was successfully synthesized by solvothermal method. The photocatalysts showed an efficient photocatalytic performance for organic pollutant under visible light irradiation. The photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflectance spectrophotometer (DRS), and photoluminescence spectroscopy (PL). The experimental results indicated that the 100 mg ZnS and 6 mg GO co-doped BiOBr (100ZBG-6) shows the highest photocatalytic activity, achieving 86.6% degradation efficiency for Rhodamine B (RhB) under visible light irradiation, which was 28.7 and 6.1 times than that of pure ZnS and BiOBr. It is indicated that the ZnS/BiOBr/GO composite has the great potential application in the degradation organic pollutant. This article describes the enhancement of light absorption and photocatalytic activity by synthesizing zinc vacancies of ZnS and introducing GO modified BiOBr.
关键词： Zinc vacancies,ZnS/BiOBr/Graphene oxide,Organic pollutant,Photocatalytic activity,Visible light
更新于2025-09-09 09:28:46
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Characterizing the size and absorption of single nonspherical aerosol particles from angularly-resolved elastic light scattering
摘要： Measuring the absorption of a single aerosol particle is a challenging endeavor. Of the few techniques available, none are suitable for measuring the single-particle absorption of coarse-mode nonspherical aerosols. Analysis of two-dimensional angular optical scattering (TAOS) patterns provide a possible pathway to perform this measurement. Using a Multiple-Sphere T-Matrix (MSTM) code, we simulate the captured TAOS patterns with geometries similar to a previously designed instrument. By analyzing the size of the speckle and the integrated irradiance of these simulated TAOS patterns, we are able to distinguish between high-absorbing, weak-absorbing, and non-absorbing particles over the size range of 2μm to 10μm. In particular, the speckle present in the scattering patterns provides a means to estimate the size of the particle. Once the size of the particle is known, the integrated irradiance provides insight into the absorption of the particle.
关键词： Absorption,Elastic Light Scattering,Aerosol,Single Particle
更新于2025-09-09 09:28:46
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doping
摘要： Results obtained on the visible light mediated photocatalytic properties of Al2O3 nanoparticles doped with Zn2+ ions synthesized by precipitation method is given in this paper. XRD, SEM, TEM, XPS, FT-IR and PL studies were performed to bring out the properties of the synthesized nanoparticles. Peaks related to monoclinic Al2O3 (θ -phase) was observed from the XRD patterns of the undoped and doped samples. A decrement of band gap from 3.86 eV to 3.71 eV with Zn doping has been observed. Oxygen vacancy related peaks were observed in the PL spectra of the samples. Enhanced degradation efficiency through Zn-doping has been observed for the Al2O3 nanoparticles against methyl orange. The maximum degradation efficiency of 90.69% observed for the 4 wt% Zn-doped Al2O3 catalyst was well acknowledged from its maximum degradation rate constant of 0.0273 min?1. The more stable nature of the Zn-doped Al2O3 photocatalysts confirmed their use as efficient photocatalysts for practical applications.
关键词： Photoluminescence,Doping,Photocatalyst,Visible light
更新于2025-09-09 09:28:46