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oe1(光电查) - 科学论文

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出版时间
  • 2019
  • 2018
研究主题
  • microwave photonics
  • interdigital resonator
  • microwave gas sensor
  • PSE-coated
  • microwave photonic mixer
  • analog optical signal processing
  • phase shift
  • photonic array antenna
  • gain
  • integrate
应用领域
  • Optoelectronic Information Science and Engineering
机构单位
  • Inner Mongolia University
  • Jinan University
  • King Mongkut’s University of Technology North Bangkok
  • Beijing University of Posts and Telecommunications
  • Wroclaw University of Technology
  • Rajamangala University of Technology Suvarnabhumi
  • Southern University of Science and Technology
  • Charles Darwin University
  • University of Ottawa
  • University of Kent
508 条数据
?? 中文（中国） ▾

  • [IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Estimation of 1-Km All-Weather Land Surface Temperature Over the Tibetan Plateau

    摘要： Land surface temperature (LST) immensely affects the energy balance and water cycle on the earth’s surface. Merging thermal infrared (TIR) and passive microwave (MW) remote sensing provides the possibility to obtain all-weather LST with moderate resolutions. However, due to difficulties in downscaling MW LST, current methods merging TIR LST and MW LST into such an all-weather LST are limited over large areas with very complicated land surfaces (e.g. the Tibetan Plateau). By fully considering the influence of the topography on estimation of merged LSTs, this study revises the recently-developed physical method for generating the 1-km all-weather LST and applies it over the Tibetan Plateau to merge MODIS (1 km) and AMSR2 (10 km) observations. Results show that the merged LST has accuracy of 0.99 K-3.22 K when validated against in-situ LSTs from five ground stations with various land cover types. This study would be beneficial for continuously monitoring LST and improving spatio-temporal resolutions for associated land surface process studies requiring high-quality all-weather LST over large scales.

    关键词： MODIS,Spatial correlations,AMSR2,Land surface temperature (LST),Passive microwave remote sensing

    更新于2025-09-23 15:21:01

  • Tunable quad-band transmission response, based on single-layer metamaterials

    摘要： We investigated the electromagnetically induced transparency (EIT)-like effects in planar metamaterials (MMs) at microwave (GHz) frequencies. The specific MMs that were used in this study consist of cut-wire resonator/ring resonator, which achieved the dual EIT-like effects in a single-layer through the bright- and quasi-dark-mode coupling and the lattice mode coupling. In addition, by varying the distance between the two resonators, the quad-band EIT spectral response in the microwave region was obtained, and the group refractive index at the EIT-like resonance of proposed design reached up to 4,000. This study provides the design approach to the multispectral EIT-like effects and might suggest potential applications in a variety of fields, for example, low-loss slow-light device, multiple switching sensor, and other sensing devices.

    关键词： microwave frequencies,slow-light device,quad-band transmission,electromagnetically induced transparency,metamaterials

    更新于2025-09-23 15:21:01

  • Synthesis and Application of Fe-Doped WO3 Nanoparticles for Photocatalytic Degradation of Methylparaben Using Visible–Light Radiation and H2O2

    摘要： Synthesis of WO3 and Fe-doped WO3 nanoparticles is done by use of Microwave irradiation technique. X-ray powder diffraction confirmed the formation of a monoclinic crystalline structure. The as-prepared samples are characterised by transmission electron microscope, Braunuer, Emmett and Teller, Raman spectroscopy, photoluminescence, X-ray photoelectron spectroscopy and ultraviolet diffuse reflectance spectroscopy. Confirmation of the morphology of the nanostructures showed ovoid-like form. The photocatalytic activity of WO3 and nominal percentage of Fe-doped WO3 (3, 5 and 10 wt%) are evaluated for the degradation of methylparaben (MeP) in aqueous solution after being irradiated with visible light. The results show that 5 wt% Fe–WO3 is the best dopant in the photodegradation of MeP at 50.8% with H2O2. A chemometric model analysis is applied to estimate both individual and interaction factors that included pH, contact time, hydrogen peroxide (H2O2) concentration and catalyst dosage. The optimal conditions at pH 3, 10 mg, 5 wt% Fe–WO3 and 120 min are achieved.

    关键词： Nanostructures,Dopant,Microwave,Methylparaben,Photodegradation

    更新于2025-09-23 15:21:01

  • Microwave Sol-Gel Derived PbY2(MoO4)4:Er3+/Yb3+ Double Molybdate and Their Up-Converted Optical Properties

    摘要： PbY2-x(MoO4)4:Er3+/Yb3+ double molybdate phosphors with the correct doped concentrations of Er3+ and Yb3+ (x = Er3+ + Yb3+, Er3+ = 0, 0.05, 0.1, 0.2 and Yb3+= 0, 0.2, 0.45) were precisely prepared using the sol-gel method assisted by the microwave technique; their up-converted optical properties were studied. The particles showed well-crystallized morphology after heat-treated at 900 °C for 16 h. They had a homogeneous and fine morphology with grain sizes of 2-5 μm. After excitation at 980 nm, the PbY1.7(MoO4)4:Er0.1/Yb0.2 and PbY1.5(MoO4)4:Er0.05/Yb0.45 double molybdates provided a strong up-converted emission band of 525 nm, a weak up-converted emission band of 550 nm in the green region and a very weak up-converted emission band of 655 nm in the red region. The spectroscopic spectra of Raman for the doped molybdates showed the presence of strong peaks at higher and lower frequencies. It was induced by highly modulated structures of PbY2-x(MoO4)4 by the incorporation of the Er3+ and Yb3+ ions into the crystal lattice. These results were attributed to the unit cell shrinkage as well as the anion deficient of the MoO4-x group.

    关键词： PbY2-x(MoO4)4:Er3+/Yb3+,Sol-gel,Up-converted photoluminescence,Raman spectroscopy,Microwave

    更新于2025-09-23 15:21:01

  • Polymers and Electromagnetic Radiation || Front Matter

    摘要： This book concentrates on the interaction of electromagnetic waves with polymers and deals only exceptionally with particle radiation. Electromagnetic waves comprise a very broad range of frequencies that extends over more than 20 orders of magnitude from the radiofrequency region up to the region of hard c-rays emitted from radionuclides or being part of the cosmic rays.

    关键词： microwave,radiofrequency,visible light,infrared radiation,gamma rays,polymers,electromagnetic waves,interaction,X-rays,ultraviolet light

    更新于2025-09-23 15:21:01

  • New Perspectives in Breast Imaging || Near-Field Radar Microwave Imaging as an Add-on Modality to Mammography

    摘要： According to global statistics, there is a high incidence of cancer in western countries; and, due to the limited resources available in most healthcare systems, it seems like one of the most feasible options to fight against cancer might be strict prevention policies—such as eliminating carcinogens in people’s daily lives. Nevertheless, early cancer detection and effective treatment are still necessary, and understanding their efficacy and limitations are important issues that need to be addressed in order to ultimately enhance patients’ survival rate. In the case of breast cancer, some of the problems faced by conventional mammography have been addressed in the literature; they include high rate of false-positive and false-negative results, as well as the possibility of overdiagnosis. New technologies, such as digital breast tomosynthesis (DBT), have been able to improve the sensitivity and specificity by using 3D imaging. However, the low contrast (1%) existing between tumors and healthy fibroglandular tissue at X-ray frequencies has been identified as one of the main causes of misdiagnosis in both conventional 2D mammography and DBT. Near-field radar imaging (NRI) provides a unique opportunity to overcome this problem, since the contrast existing between the aforementioned tissues is intrinsically higher (10%) at microwave frequencies. Moreover, the low resolution and highly complex scattering patterns of microwave systems can be enhanced by using prior information from other modalities, such as the DBT. Therefore, a multimodal DBT/NRI imaging system is proposed to exploit their individual strengths while minimizing their weaknesses. In this work, the foundation of this idea is reviewed, and a preliminary design and experimental validation of the NRI system, used as a DBT complement, is introduced.

    关键词： breast cancer statistics,digital breast tomosynthesis,microwave imaging,antipodal Vivaldi antennas,near-field radar imaging,breast cancer detection

    更新于2025-09-23 15:21:01

  • [IEEE 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Fukuoka, Japan (2019.7.7-2019.7.11)] 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Plasmonics for Communications

    摘要： The Global Change Observation Mission 1st-Water (GCOM-W1) satellite, launched by the Japan Aerospace Exploration Agency in May 2012, contains an Advanced Microwave Scanning Radiometer-2 (AMSR2). The AMSR2 provides multifrequency measurements of microwave energy (brightness temperature) emitted by the Earth’s surface and atmosphere. However, each frequency field of view (FOV) differs in size because of its hardware design. For the retrieval of more accurate geophysical parameters from multifrequency brightness temperatures, the brightness temperatures should be modified to be the same as measured in the same FOV. The Backus–Gilbert (BG) method is one of the antenna pattern matching techniques used for this modification. We applied the BG method to the AMSR2 data to define a new data set of modified brightness temperatures, a level 1R (L1R) product that is freely and widely available. We optimized the implementation of the BG method to obtain the L1R product, with smoothing factors dynamically determined for all modified brightness temperatures. This paper describes the implementation method, including the criterion used to determine the smoothing factors and presents a quality assessment of the L1R product.

    关键词： Backus–Gilbert (BG) method,water cycle monitoring,microwave radiometer,convolution,field of view (FOV),Advanced Microwave Scanning Radiometer-2 (AMSR2)

    更新于2025-09-23 15:19:57

  • Q-switched fiber laser based on CdS quantum dots as a saturable absorber

    摘要： In this work, a Q-switched fiber laser is demonstrated using quantum dots (QDs) cadmium sulfide (CdS) as a saturable absorber (SA) in an erbium-doped fiber laser (EDFL) system. The QD CdS is synthesized via the microwave hydrothermal assisted method and embedded into polyvinyl alcohol (PVA). The QD CdS/PVA matrix film is sandwiched in between two fiber ferrules by a fiber adapter. The generation of Q-switched fiber laser having a repetition rate, a pulse width, and a peak-to-peak pulse duration of 75.19 kHz, 1.27 μs, and 13.32 μs, respectively. The maximum output power of 3.82 mW and maximum pulse energy of 50.8 nJ are obtained at the maximum pump power of 145.9 mW. The proposed design may add to the alternative material of Q-switched fiber laser generation, which gives a high stability output performance by using quantum dots material as a saturable absorber.

    关键词： CdS Quantum Dots,erbium-doped fiber laser,microwave hydrothermal assisted method,saturable absorber,Q-switched fiber laser

    更新于2025-09-23 15:19:57

  • Sampled-Data Adaptive ESO Based Composite Control for Nano-Positioning Systems

    摘要： In this paper, we demonstrate ultra-fast millimeter wave beam steering with settling times below 50 ps. A phased array antenna with two elements is employed to realize beam steering. The phased array feeder is implemented with a recently introduced time delay line that provides, at the same time, an ultra-fast tunability, broadband operation, and continuous tuning. Our implementation is used to perform symbol-by-symbol steering. In our demonstration, the beam direction is switched between two sequentially transmitted symbols toward two receivers placed 30° apart. We show the successful symbol-by-symbol steering for data streams as fast as 10 GBd. The suggested scheme shows that the ultra-fast beam steering is becoming practical and might ultimately enable novel high bit-rate multiple access schemes.

    关键词： microwave photonics,millimeter wave communication,Ultra-fast beam steering,radio access network

    更新于2025-09-23 15:19:57

  • Femtosecond-laser-irradiation-induced structural organization and crystallinity of Bi2WO6

    摘要： controlling the structural organization and crystallinity of functional oxides is key to enhancing their performance in technological applications. in this work, we report a strong enhancement of the structural organization and crystallinity of Bi2Wo6 samples synthetized by a microwave-assisted hydrothermal method after exposing them to femtosecond laser irradiation. X-ray diffraction, UV-vis and Raman spectroscopies, photoluminescence emissions, energy dispersive spectroscopy, field emission scanning electron microscopy, and transmission electron microscopy were employed to characterize the as-synthetized samples. To complement and rationalize the experimental results, first-principles calculations were employed to study the effects of femtosecond laser irradiation. Structural and electronic effects induced by femtosecond laser irradiation enhance the long-range crystallinity while decreasing the free carrier density, as it takes place in the amorphous and liquid states. these effects can be considered a clear cut case of surface-enhanced Raman scattering.

    关键词： structural organization,Bi2WO6,femtosecond laser irradiation,crystallinity,microwave-assisted hydrothermal method

    更新于2025-09-23 15:19:57