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- 摘要
- 关键词
- 实验方案
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过滤筛选
- 2018
- imgae sensor
- internet of things
- drone
- visible light ID
- Signal-to-Noise Ratio (SNR)
- Infinite Gain Multiple Feedback (IGMF)
- Visible Light Communications (VLC)
- LED
- Trans-Impedance Amplifier (TIA)
- Optoelectronic Information Science and Engineering
- Tohoku University
- University of Northumbria
- University of Huddersfield
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Simplified Vehicle Vibration Modeling for Image Sensor Communication
摘要： Image sensor communication (ISC), derived from visible light communication (VLC) is an attractive solution for outdoor mobile environments, particularly for intelligent transport systems (ITS). In ITS-ISC, tracking a transmitter in the image plane is critical issue since vehicle vibrations make it difficult to select the correct pixels for data reception. Our goal in this study is to develop a precise tracking method. To accomplish this, vehicle vibration modeling and its parameters estimation, i.e., representative frequencies and their amplitudes for inherent vehicle vibration, and the variance of the Gaussian random process representing road surface irregularity, are required. In this paper, we measured actual vehicle vibration in a driving situation and determined parameters based on the frequency characteristics. Then, we demonstrate that vehicle vibration that induces transmitter displacement in an image plane can be modeled by only Gaussian random processes that represent road surface irregularity when a high frame rate (e.g., 1000 fps) image sensor is used as an ISC receiver. The simplified vehicle vibration model and its parameters are evaluated by numerical analysis and experimental measurement and obtained result shows that the proposed model can reproduce the characteristics of the transmitter displacement sufficiently.
关键词： vehicle motion model,vehicle vibration,visible light communication,image sensor communication,road surface irregularity,transmitter displacement
更新于2025-09-23 15:22:29
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A Nondestructive Real-Time Detection Method of Total Viable Count in Pork by Hyperspectral Imaging Technique
摘要： A nondestructive method was developed for assessing total viable count (TVC) in pork during refrigerated storage by using hyperspectral imaging technique in this study. The hyperspectral images in the visible/near-infrared (VIS/NIR) region of 400–1100 nm were acquired for fifty pork samples, and their VIS/NIR diffuse reflectance spectra were extracted from the images. The reference values of TVC in pork samples were determined by classical microbiological plating method. Both partial least square regression (PLSR) model and support vector machine regression model (SVR) of TVC were built for comparative analysis to achieve better results. Different transformation methods and filtering methods were applied to improve the models. The results show that both the optimized PLSR model and SVR model can predict the TVC very well, while the SVR model based on second derivation was better, which achieved with RP (correlation coefficient of prediction set) = 0.94 and SEP (standard error of prediction set) = 0.4570 log CFU/g in the prediction set. An image processing algorithm was then developed to transfer the prediction model to every pixel of the image of the entire sample; the visualizing map of TVC would be displayed in real-time during the detection process due to the simplicity of the model. The results demonstrated that hyperspectral imaging is a potential reliable approach for non-destructive and real-time prediction of TVC in pork.
关键词： visible/near-infrared,total viable count,pork,hyperspectral imaging
更新于2025-09-23 15:22:29
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Visible-Light-Driven Photocatalytic Z-scheme Overall Water Splitting in La5Ti2AgS5O7-based Powder Suspension System
摘要： La5Ti2CuxAg1-xS5O7 (x=0-1) is a kind of long-wavelength-responsive oxysulfide photocatalysts for hydrogen evolution, and has been demonstrated to enable the Z-scheme water splitting coupling with oxygen evolution photocatalysts (OEP) the particulate sheet. We herein report that among La5Ti2CuxAg1-xS5O7, La5Ti2AgS5O7 was found to have the highest performance on Z-scheme overall water splitting in conjunction with PtOx-WO3 as an OEP, and a triiodide/iodide (I3?/I?) redox couple as a shuttle electron mediator in powder suspension system. Loading Pt/NiS on La5Ti2AgS5O7 benefits the Z-scheme to achieve an apparent quantum yield of 0.12% at 420 nm. The finding in powder suspension system is opposite to the earlier study on photocatalyst sheet configurations in which p-type doping and the formation of a solid solution can effectively enhance the water-splitting activity. This work not only shows a La5Ti2AgS5O7-based Z-scheme water splitting photocatalyst, but also may present a better understanding for the difference between particulate sheet and powder suspension system available in an optimal strategy for water splitting.
关键词： photocatalysis,water splitting,visible light,Z-scheme,oxysulfides
更新于2025-09-23 15:22:29
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Colorimetric detection and typing of E. coli lipopolysaccharides based on a?dual aptamer-functionalized gold nanoparticle probe
摘要： A rapid method for identification and typing of lipopolysaccharides (LPS) was developed by utilizing the different binding affinities between two kinds of gold nanoparticles (AuNPs) functionalized with two aptamers. Aptamers against ethanolamine and E. coli O111:B4 LPS were used to functionalize the AuNPs. The AuNPs functionalized with ethanolamine aptamer can bind to ethanolamine and are termed general probe (G-probe). The G-probe can recognize any type of LPS because ethanolamine is a component of every type of LPS. This causes a sandwich-mediated aggregation of the AuNPs and a color change from red to blue. The AuNPs functionalized with aptamer against the LPS of E. coli O111:B4 specifically bind to O111:B4 LPS and are termed specific probe (S-probe). By using these two probes, a logic typing method was developed. It can detect LPS in concentrations between 2.5 and 20 μg·mL?1 and with a 1 μg·mL?1 detection limit. In the authors’ perception, the use of a dual aptamer-based colorimetric method has a large potential in terms of selective detection of microorganisms.
关键词： Logic typing,O55:B5,Aptasensor,O111:B4,Visible,Ethanolamine
更新于2025-09-23 15:22:29
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Electrochemical synthesis of copper(II) oxide nanorods and their application in photocatalytic reactions
摘要： A new way of synthesizing nanoscale copper oxide particles is described in this work. Oxides of an intermediate metal, such as copper oxide, can be used as an effective semiconductor in the photocatalytic reactions once they are prepared in a special way. The CuO nanorods were synthesized electrochemically under surfactant-free, static conditions. The obtained nanorods have an average length of less than 50 nm. The CuO nanorods were used as a heterogeneous catalyst in an aqueous medium. 2,4-Dichlorophenol (DCP) was used as a probe molecule. The CuO nanorods showed an excellent ability to degrade DCP under visible light and without the need for any auxiliary oxidizing agent.
关键词： CuO,DCP,Visible light,Degradation,Nanorods,Heterogeneous catalyst
更新于2025-09-23 15:22:29
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ZnO/CdS/PbS nanotube arrays with multi-heterojunctions for efficient visible-light-driven photoelectrochemical hydrogen evolution
摘要： High performance, low cost and sustainable photocatalytic evolution of hydrogen is a promising energy supply alternative for modern society to resolve the depletion crisis of fossil fuel. The design of multi-heterojunction visible-light photocatalysts combined with electrochemical means is considered one of the most attractive options in recent years. In this work, a photoanode composed of top-opened ZnO/CdS/PbS nanotube arrays (ZnO/CdS/PbS ONTs) with multi-heterojunctions was synthesized via a three-step process, i.e. hydrothermal treatment, chemical bath deposition and successive ionic layer adsorption reaction (SILAR). This as-prepared photoanode exhibited remarkable photoelectrochemical activity under visible light irradiation. The photocurrent density and photoelectrochemical hydrogen evolution efficiency of the optimized ZnO/CdS/PbS ONTs reached up to 14.2 mA cm-2 and 5.5 mL cm-2 h-1 at 0.0 V vs. Ag/AgCl, respectively. The efficiency was 3.1 times that of top-closed ZnO/CdS nanotubes (1.8 mL cm-2 h-1). The experimental results suggest that the high photoelectrochemical activity can be ascribed to the inherent advantages of the structural and successive energy level relays design: on the one hand, the top-opened nanotube structure significantly enlarges surface area of the nanostructure, which facilitates efficient light absorption and rapid mass transport; on the other hand, the well-matched band energy edge of the multi-heterojunction interfaces literally build efficient electron highways to deliver electrons to reaction sites and reduce the recombination of photogenerated charge carriers.
关键词： CdS,visible light,multi-heterojunction,ZnO,photoelectrochemical hydrogen evolution,PbS
更新于2025-09-23 15:22:29
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Efficient visible-light-responsive photocatalyst: Hybrid TiO2-Ag3PO4 nanorods
摘要： Herein, ordered TiO2-Ag3PO4 nanorods are fabricated by loading Ag3PO4 nanoparticles on the as-prepared brookite TiO2 nanorods. The amount of Ag3PO4 nanoparticles loaded on brookite TiO2 nanorods can be rationally optimized. These hybrid TiO2-Ag3PO4 nanorods could provide large surface area, extend the visible light absorption and facilitate the charge separation, leading to efficient visible-light-driven photocatalytic performance. When evaluated as photocatalysts under visible light illumination, all the hybrid TiO2-Ag3PO4 nanorods exhibit high photocatalytic activity for degrading 2-propanol. Particularly, TiO2-Ag3PO4-3 enables the best photocatalytic property, which yields high acetone production of 147 ppm at 3 h and CO2 production of 424 ppm at 11 h.
关键词： TiO2-Ag3PO4,Visible-light-responsive,Nanocomposites,Solar energy materials
更新于2025-09-23 15:22:29
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Synthesis of C-In2O3/BiOI composite and its enhanced photocatalytic degradation for methyl blue
摘要： In this work, C-In2O3/BiOI composite is synthesized and used as a high performance photocatalyst for photocatalytic degradation of methyl blue (MB) in wastewater. The C-In2O3/BiOI composites demonstrate 5 times higher photocatalytic performance than the pristine BiOI and In2O3 for MB degradation under the irradiation of visible light. Furthermore, the C-In2O3/BiOI composites have excellent cycling stability. Such enhanced photoactivity is due to the significantly enhanced separation efficiency of photogenerated. This work provides some significance in the design and construction of environmentally benign catalysts with excellent photocatalytic degradation of toxic pollutants.
关键词： C-In2O3/BiOI,Methyl blue,Photocatalysis,Visible light
更新于2025-09-23 15:22:29
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Synergetic utilization of photoabsorption and surface facet in crystalline/amorphous contacted BiOCl-Bi2S3 composite for photocatalytic degradation
摘要： Photoabsorption and surface property of semiconductor are two key factors to determine its photocatalytic performance. In this work, BiOCl-Bi2S3 composites composed of Bi2S3 nanoparticles bonded on BiOCl nanoplates enclosed with {001} and {110} crystal facets were synthesized through an in-situ ion exchange method at room temperature. The transformed Bi2S3 made BiOCl-Bi2S3 composites efficient visible light absorption, ensuring the quantity of photoinduced carriers as well as intimate crystalline-amorphous contact interface to benefit the separation of photoinduced carriers. Moreover, BiOCl nanoplates enclosed with {001} and {110} crystal facets can convenient transfer carriers to {001} crystal facets. The photocatalytic performance of BiOCl-Bi2S3 composites was evaluated by the methylene blue photodegradation under visible light irradiation and the results indicate that BiOCl-Bi2S3 composites have good photocatalytic ability due to enhanced light absorption, efficient separation and transfer of carriers. Based on the active species trapping experiments, transient photocurrents, electrochemical impedance spectroscopy and energy band structure, a possible photocatalytic mechanism of methylene blue over the BiOCl-Bi2S3 composites was proposed.
关键词： Surface property,Visible light,BiOCl-Bi2S3,Contact interface,Photocatalytic mechanism,Crystal facet
更新于2025-09-23 15:22:29
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Hybrid TDOA/RSS based localization for visible light systems
摘要： In a visible light positioning (VLP) system, a receiver can estimate its location based on signals transmitted by light emitting diodes (LEDs). In this manuscript, we investigate a quasi-synchronous VLP system, in which the LED transmitters are synchronous among themselves but are not synchronized with the receiver. In quasi-synchronous VLP systems, position estimation can be performed by utilizing time difference of arrival (TDOA) information together with channel attenuation information, leading to a hybrid localization system. To specify accuracy limits for quasi-synchronous VLP systems, the Cramér–Rao lower bound (CRLB) on position estimation is derived in a generic three-dimensional scenario. Then, a direct positioning approach is adopted to obtain the maximum likelihood (ML) position estimator based directly on received signals from LED transmitters. In addition, a two-step position estimator is proposed, where TDOA and received signal strength (RSS) estimates are obtained in the first step and the position estimation is performed, based on the TDOA and RSS estimates, in the second step. The performance of the two-step positioning technique is shown to converge to that of direct positioning at high signal-to-noise ratios based on asymptotic properties of ML estimation. Finally, CRLBs and performance of the proposed positioning techniques are investigated through simulations.
关键词： Received signal strength (RSS),Estimation,Visible light,Localization,Time difference of arrival (TDOA)
更新于2025-09-23 15:22:29