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oe1(光电查) - 科学论文

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出版时间
  • 2018
研究主题
  • 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)
应用领域
  • Optoelectronic Information Science and Engineering
机构单位
  • Tohoku University
  • University of Northumbria
  • University of Huddersfield
645 条数据
?? 中文（中国） ▾

  • Indoor Localization Using K-Pairwise Light Emitting Diode Image-Sensor-Based Visible Light Positioning

    摘要： A great deal of research has been devoted to studying indoor localization schemes for the development of location-based services. This study investigated an indoor localization system, including subsystems of non-line-of-sight (NLOS) image-sensor-based visible light communications (IS-VLC) and the proposed ??-pairwise light emitting diode (LED) image-sensor-based visible light positioning (IS-VLP), in a unified lighting environment. A smartphone received multiple LED identifiers through the designed NLOS IS-VLC and successfully performed the proposed ??-pairwise LED IS-VLP with ?? = 3 to achieve localization, with maximum localization errors of 2.92 cm and 3.54 cm being obtained for ceiling heights of 100 cm and 150 cm, respectively.

    关键词： visible light communications (VLC),Image-sensor-based visible light positioning (VLP),light emitting diode (LED)

    更新于2025-09-23 15:21:21

  • Bio-inspired Z-scheme g-C3N4/Ag2CrO4 for efficient visible-light photocatalytic hydrogen generation

    摘要： Due to low charge separation efficiency and poor stability, it is usually difficult for single-component photocatalysts such as graphitic carbon nitride (g-C3N4) and silver chromate (Ag2CrO4) to fulfill photocatalytic hydrogen production efficiently. Z-scheme charge transport mechanism that mimics the photosynthesis in nature is an effective way to solve the above problems. Inspired by photosynthesis, we report Ag2CrO4 nanoparticles-decorated g-C3N4 nanosheet as an efficient photocatalyst for hydrogen evolution reaction (HER) with methanol as sacrificial agent. The formation of Z-scheme g-C3N4/Ag2CrO4 nanosheets photocatalysts could inhibit the recombination of photogenerated electron-hole pairs, promote the generation of hydrogen by photosplitting of water. The experiment results indicate that g-C3N4/Ag2CrO4 nanocomposites present enhanced photocatalytic activity and stability in the H2 evolution of water splitting. And the nanocomposites g-C3N4/Ag2CrO4(23.1%) show the 14 times HER efficiency compared to that of bare g-C3N4.

    关键词： visible-light,Z-scheme,hydrogen production,g-C3N4,Ag2CrO4,photocatalysts

    更新于2025-09-23 15:21:21

  • A critical review on visible-light-response CeO2-based photocatalysts with enhanced photooxidation of organic pollutants

    摘要： Organic pollutants’ treatment in wastewater has attracted extensive attention due to its degradation-resistance and potentially hazardous to human health. Some organic matters such as persistent organic pollutants (POPs) could exist in environment and resist to decomposition, which may cause chronic intoxication or even cancers. Because photocatalytic technique is efficient, nontoxic, and cost-effective to degrade organic pollutants, some semiconductors including TiO2 and ZnO as photocatalysts have aroused wide public concern. CeO2 has been reported as an efficient photocatalyst in contrast to TiO2 owing to its high oxygen storage, eco-friendly properties and photostability. But inefficient utilization of solar energy due to its intrinsic wide bandgap restrains its further application in real environmental pollutant treatment. In order to improve photocatalytic performances of CeO2, some modifications have been developed such as doping ions, coupling with semiconductor and construction of CeO2-based solid-solution. The purpose of this review is to introduce these techniques, reveals its fundamental mechanisms and the recent researches about photodegradation of organic pollutants in wastewater over CeO2-based photocatalysts. Besides, this review will evaluate the photocatalytic performance for organic pollutants and outlook the challenges and prospects in the future.

    关键词： Modification,CeO2,Visible-light-response,Photodegradation,Organic pollutants

    更新于2025-09-23 15:21:21

  • Wet NH3-Triggered NH2-MIL-125(Ti) Structural Switch for Visible Fluorescence Immunoassay Impregnated on Paper

    摘要： This work has looked to explore an innovative and powerful visible fluorescence immunoassay method through wet NH3-triggered structural change of NH2-MIL-125(Ti) impregnated on paper for the detection of carcinoembryonic antigen (CEA). Gold nanoparticles heavily functionalized with glutamate dehydrogenase (GDH) and secondary antibody were used for generation of wet NH3 with a sandwiched immunoassay format. Paper-based analytical device (PAD) coated with NH2-MIL-125(Ti) exhibited good visible fluorescence intensity through wet NH3-triggeried structural change with high accuracy and reproducibility. Moreover, NH2-MIL-125(Ti)-based PAD displayed two visual modes of fluorescence color and physical color with naked eyes, and allowed the detection of CEA at a concentration as low as 0.041 ng mL-1. Importantly, the PAD-based assay provides promise for use in the mass production of miniaturized devices and opens new opportunities for protein diagnostics and biosecurity.

    关键词： paper-based analytical device,NH2-MIL-125(Ti),visible fluorescence immunoassay,wet NH3,carcinoembryonic antigen

    更新于2025-09-23 15:21:21

  • Rational band design in metal chalcogenide Ba6Zn6HfS14: splitting orbitals, narrowing forbidden gap and boosting photocatalyst property

    摘要： The insufficient light sources absorption often limits photocatalyst applications of metal chalcogenides because of their excessively broad band gap. Thus, it is necessary to discover and design a compound with rational band gap. Here, a new visible-light photocatalyst, Ba6Zn6HfS14, is prepared through the traditional high temperature solid-state reaction. A set of experiments on the visible-light decomposition of methylene blue demonstrated that the photocatalytic efficiency of Ba6Zn6HfS14 (0.00761 min-1) is improved, compared to that of Ba6Zn6ZrS14 (0.00553 min-1) which proved to be a previously reported visible-light photocatalyst with similar structure. The UV-visible reflection spectra demonstrated the energy gap of Ba6Zn6HfS14 (E1=1.45eV; E2 =2.55eV) is smaller than that of Ba6Zn6ZrS14 (E1 = 1.78eV; E2 = 2.50eV; E3 = 2.65eV). The Ba6Zn6HfS14 absorbs more visible light and exhibits preferably photocatalytic activity. The origin of splitted energy bands were elucidated via the first calculations.

    关键词： band gap engineering,chalcogenides,visible-light photocatalyst

    更新于2025-09-23 15:21:21

  • Effect of metal doped and co-doped TiO2 photocatalysts oriented to degrade indoor/outdoor pollutants for air quality improvement. A kinetic and product study using acetaldehyde as probe molecule

    摘要： This study demonstrates the photocatalytic decomposition of an indoor air pollutant, acetaldehyde (CH3CHO), over 0.04 mol% metal-doped TiO2 (Mn-, Co- and Mn/Co-) nanoparticles activated by ultraviolet and visible irradiation. The photocatalytic activity, the photodegradation kinetics, and the ?nal product analysis were examined using a Static Photochemical Reactor coupled with a FTIR spectrophotometer. CH3CHO undergoes ef?cient decomposition over all photocatalysts under UV irradiation in the presence of one atmosphere N2 or synthetic air (SA). Metal doping causes substantial in?uence to photocatalysis by altering the amount of electron/hole pairs generated and/or the electron/hole recombination rates. Simulating the experimental results with pseudo-?rst order kinetics the corresponding degradation rate coe?cients were determined for each photocatalyst under UV irradiation and SA environment: kd UV(Mn-TiO2) = (1.9 ± 0.2)×10 ?1 h ?1, kd UV(Co-TiO2) = (2.8 ± 0.3)×10 ?1 h ?1, and kd UV(Mn/Co-TiO2) = (6.0 ± 0.7)×10 ?1 h ?1. These degradation kinetics under UV light irradiation are signi?cantly faster than undoped TiO2 revealing that the transition metal doping of TiO2 nanomaterials boosts the photocatalytic degradation of organic pollutants. Substantial decomposition of CH3CHO was achieved under visible light in the presence of oxygen over Mn-TiO2 with kd Vis(SA) = (0.44 ± 0.04)×10 ?1 h ?1 while for other samples no visible light photocatalysis was observed. CO2, CO, and H2O were the main oxidation products, with CO2 yields almost 100% under UV excitation, and CO yields up to 20% under UV and < 1% under visible excitation. Our experimental results suggest that Mn-TiO2 (0.04 mol%) nanoparticles may be considered as a potentially safe photocatalyst to remove acetaldehyde particularly from indoor atmospheric environments under visible irradiation, without yielding signi?cant toxic by-products. Other possible atmospheric implications are also discussed in the paper.

    关键词： Metal-doped TiO2,Visible-ultraviolet photocatalysis,Photodegradation kinetics,Acetaldehyde,Indoor air pollution

    更新于2025-09-23 15:21:21

  • In situ high-pressure spectroscopic studies using moissanite (4H-SiC) anvils

    摘要： We examined the Raman scattering and IR absorption spectroscopy of 4H-SiC and its performance as an anvil material for high-pressure UV-visible absorption spectroscopic measurements. The first- and second-order Raman peaks of 4H-SiC and diamond do not coincide. 4H-SiC does not have obvious signals from 2330-5000 cm-1, suggesting that 4H-SiC anvils are beneficial for high-pressure studies of samples whose Raman signals locate in the region of diamond. Above 1800 cm-1, the transmitted signal of 4H-SiC in the IR absorption spectra, measured through 4.6 mm thickness is much higher than that of type IIa diamond. An in situ high-pressure UV-visible absorption spectroscopy study on CdI2 was carried out up to 28.0 GPa using 4H-SiC anvil cells (4H-SAC) with a 400 μm culet and the acquired band gap narrowed with increasing pressure. These results show that 4H-SiC has an excellent performance in high-pressure spectroscopic studies.

    关键词： IR absorption spectroscopy,high-pressure,UV-visible absorption spectroscopy,Raman spectroscopy,4H-SiC

    更新于2025-09-23 15:21:21

  • Dimming Control Systems Based on Low-PAPR SCFDM for Visible Light Communications

    摘要： In this paper, the efficient dimming control systems based on single-carrier frequency-division multiplexing (SCFDM) are proposed for visible light communications (VLC). By virtue of the strengths of the low peak-to-average power ratio and the inherent resistance to high-frequency distortion, the proposed SCFDM-based dimming control schemes are adaptive to the bandwidth-limited and linearity-limited VLC system, thus supporting the wide dimming range for different illumination requirements. Two SCFDM-based VLC systems with dimming control including asymmetrical hybrid optical SCFDM (AHO-SCFDM) and DC-biased optical SCFDM (DCO-SCFDM) are proposed. For AHO-SCFDM with spectral efficiency of 1.75 bit/s/Hz and DCO-SCFDM with spectral efficiency of 2 bit/s/Hz, the 20% wider dimming range can be achieved than their orthogonal frequency-division multiplexing (OFDM) based counterparts, respectively. Meanwhile, the two proposed schemes can also achieve 24.8% and 31.3% gains of average spectral efficiency under the same dimming range compared with their counterparts, respectively. For an overall analysis, SCFDM shows the feasibility and superiority for dimming control systems.

    关键词： light emitting diode,Visible light communication,single-carrier frequency-division multiplexing,dimming control,orthogonal frequency-division multiplexing

    更新于2025-09-23 15:21:21

  • IEEE Access Special Section Editorial: Optical Wireless Technologies for 5G Communications and Beyond

    摘要： Wide bandwidth and dense spatial reuse are of extreme importance for future wireless communication networks, including 5G and beyond. In particular, these properties are important to enable future wireless networks to cope with the explosive increase in the demand for high data-rate communications. Optical wireless communications (OWC) is a promising technology for achieving this goal due to the abundant reusable license-free optical spectrum. This potential of OWC attracted significant global attention both from communications and optoelectronics viewpoints, and continues to do so.

    关键词： 5G,beam-steering,mixed FSO/fiber backhauling,OFDM,MIMO,Optical wireless communications,vehicle-to-vehicle communications,free-space optics,vehicle-to-infrastructure communications,network-layer aspects,visible-light communications

    更新于2025-09-23 15:21:21

  • RECENT APPLICATIONS IN ORGANIC SYNTHESIS OF VISIBLE LIGHT PHOTOREDOX CATALYSIS

    摘要： RECENT APPLICATIONS IN ORGANIC SYNTHESIS OF VISIBLE LIGHT PHOTOREDOX CATALYSIS. In the past few years, photoredox catalysis has become a powerful tool in the field of organic synthesis. Using this efficient method, it is possible to excite organic compounds from visible light and attain alternative mechanistic pathways for the formation of chemical bonds, a result which is not obtainable by classical methods. The rapid growth of work in the area of photoredox catalysis is due to its low cost, broad chemical utility protocols, and, especially, its relevancy from the green and sustainable chemistry viewpoints. Thus, this study proposes a brief theoretical discussion of and highlights recent advances in visible-light-induced photoredox catalysis through the analysis of catalytic cycles and intermediates.

    关键词： visible light,photoredox catalysis,organocatalysis,organic synthesis,transition metals

    更新于2025-09-23 15:21:21