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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
  • electropolymerization
  • polyporphyrin films
  • quartz crystal microbalance method
  • oxygen electroreduction.
  • supercontinuum generation
  • Nonlinear
  • photonic crystal fiber taper
应用领域
  • Applied Chemistry
  • Optoelectronic Information Science and Engineering
机构单位
  • Beijing University of Posts and Telecommunications (BUPT)
  • G.A. Krestov Institute of Solution Chemistry of RAS
  • University Union Nicola Tesla
  • Ivanovo State University of Chemistry and Technology
965 条数据
?? 中文(中国)
  • Incompressible limit for compressible nematic liquid crystal flows in a bounded domain

    摘要: In this paper, we consider the incompressible limit of strong solution for the compressible nematic liquid crystal flows in a 3D bounded domain (cid:2) ? R3 where the the velocity field satisfies the Dirichlet boundary condition. We establish the uniform estimates with respect to the Mach number for the strong solutions with large initial data in a short time interval. Consequently, we obtain the convergence of the compressible nematic liquid crystal system to the incompressible nematic liquid crystals system as the Mach number tends to zero.

    关键词: Incompressible limit,Dirichlet boundary condition,compressible nematic liquid crystal equations

    更新于2025-09-23 15:23:52

  • Step-shaped electrode for low-voltage and high-optical-efficiency blue-phase transflective liquid crystal displays

    摘要: A step-shaped electrode design is proposed for Polymer Stabilised Blue Phase (PSBP) Transflective LCD (TR-LCD). This new electrode design is capable of delivering very high optical efficiency (both T and R) of >95% with operation voltage of ~13 V (or >~90% with ~9 V). The step-shaped electrode helps generate strong horizontal electric fields across the whole cell and suppress the formation of dead zone.

    关键词: transflective,Liquid crystal display,step-shaped electrode,blue phase

    更新于2025-09-23 15:23:52

  • Electrically tuned microwave CP cross slot patch antenna using liquid crystal technology

    摘要: The rapid progress in material science and electronic technology is great possibility in designing reconfigurable wireless devices which are frequency tunable, flexible and consume low energy. In this paper, the anisotropic propriety of a new liquid crystal mixture 'GT3-23001' in their nematic phase are exploited for designing tunable circular polarized cross slot patch antenna for WLAN applications. Reconfiguration of frequency response is controlled through an electrical external command. The proposed reconfigurable antenna based on liquid crystal satisfies a continuous frequency tuning of 15.83% with a global bandwidth of around 467.92 MHz (19.5%). to validate this novel mixture of liquid crystal, the simulated results are compared with the measured data and a good agreement is noticed.

    关键词: liquid crystal mixture,Material science,tunable patch,circular polarized,reconfigurable,frequency tuning

    更新于2025-09-23 15:23:52

  • Correlation between magneto-optical and transport properties of Sr doped manganite films

    摘要: The features of electronic structure of La0.7Sr0.3MnO3, Pr0.8Sr0.2MnO3, and Pr0.6Sr0.4MnO3 polycrystalline films of different thickness have been investigated using magnetic circular dichroism (MCD) in the range of 1.1e4.2 eV. The temperature behavior of the samples electrical resistance were also has been studied. It was found that films with high Sr content (0.3 and 0.4) act as high-temperature semiconductors, while the maximum in the temperature dependences of resistivity these films indicates the transition of the samples to the metallic state at some temperature TM-S, which is different for different sample thickness. The films with the lower Sr content (0.2) act as insulators in the used temperature range. The MCD spectra have been decomposed to the Gaussian-shaped lines, and the temperature dependence of intensity of each line has been analyzed in comparison with temperature dependence of the films magnetization and with their electric conductivity type. Different temperature behavior of the intensity of four specified Gaussian-lines was revealed for semiconductor films. In the case of insulating Pr0.8Sr0.2MnO3 samples, the intensity of three specified Gaussian lines changes with the temperature in the same way as the magnetization changed. It was established that the lanthanide (La, Pr) type does not affect the MCD spectra shape for the films with the same electrical conductivity type. Besides, the correlation between the MCD data of the films and their conductivity type was revealed. Due to the detailed analysis of the specified Gaussian lines with taking into account the well-known in the literature absorption bands, lying outside the studied spectral region, the MCD bands for the studied manganite films have been identified with electronic transitions of a different nature.

    关键词: Magnetic circular dichroism,Thin films,Electronic properties,Electrical transport,Crystal structure,Manganites

    更新于2025-09-23 15:23:52

  • 2D ultra-thin WO3 nanosheets with dominant {002} crystal facets for high-performance xylene sensing and methyl orange photocatalytic degradation

    摘要: Here we report the synthesis of two-dimensional (2D) ultra-thin WO3 nanosheets (~4.9 nm) with dominant {002} crystal facets through a facile surfactant-induced self-assembly method. It was found that the ultra-thin WO3 nanosheets showed remarkably enhanced xylene sensing performance and methyl orange photocatalytic degradation performance, which could be ascribed to the high percentage of reactive {002} crystal facets (>90%) and high specific surface area (121 m2/g). The mechanism of gas sensing and photocatalysis was systematically studied. This work will be intriguing for designing high-performance metal oxides-based gas sensing and photocatalytic materials through 2D structural modulation and crystal facets engineering, which is important to promote their practical applications in environmental issues.

    关键词: {002} crystal facets,2D,Photocatalysis,WO3,Gas sensing

    更新于2025-09-23 15:23:52

  • A series of germanotungstate-based 3d-4f heterometallic compounds with visible-light induced photocatalytic, electrochemical and magnetic properties

    摘要: A series of 3d-4f heterometallic germanotungstate dimers {[Cu(dap)(H2O)3][LnCu3(dap)3(OH)3(H2O)2(GeW11O39)]}·nH2O (Ln = SmⅢ, n = 11 (1), EuⅢ, n = 12 (2), GdⅢ, n = 10 (3) and TbⅢ, n = 13 (4); dap = 1, 2-diaminopropane) have been prepared under hydrothermal conditions and structurally characterized by IR, UV-Vis, XRD, and X-ray single-crystal diffraction. Compounds 1–4 are essentially isomorphic and display organic-inorganic hybrid dimeric structures consisting of [LnCu3(dap)3(OH)3(H2O)(GeW11O39)]2 4– with two supporting [Cu(dap)(H2O)3]2+ cations on both sides. The four compounds all exhibit the excellent photocatalytic activities to delaradation of methylene blue (MB) and rhodamine-B (RhB) under visible light irradiation in the presence of H2O2. Additionally, 1–4 displays an apparent electrocatalytic activity for the reduction of hydrogen peroxide. The variable-temperature magnetic studies show that the magnetic behaviours of 1, 2 and 4 are dominated by antiferromagnetic coupling interactions, while that of 3 is ferromagnetic interactions coexist along with antiferromagnetic interactions.

    关键词: Photocatalytic properties,Lacunary polyoxometalates,magnetic properties,Crystal structure,Electrocatalytic properties,3d-4f Heterometallic compounds

    更新于2025-09-23 15:23:52

  • Shock wave induced enhancement of optical properties of benzil crystal

    摘要: In this article, we present the results of the experimental work on the impact of shock waves on optical properties of benzyl crystalline material. Test material of benzil crystal is grown along [100] plane by Sankaranarayana - Ramasamy method. In the present work, the functional shock waves of Mach number 1.7 are generated from pressure driven shock tube. The optical properties of test material are investigated by UV-Visible spectrometer over the range between 200 and 800nm. The observed results show that the intensity of the absorption spectrum is inversely proportional to the number of exposed shock waves. The direct and indirect optical band gap energy (Eg) and Urbach tail energy (Ug) are determined from the optical absorption spectrum for pre and post shock wave loaded condition and found that shock wave loaded test crystal has high band gap energy. The optical constants namely extinction coefficient, real and imaginary parts of the dielectric constant, skin depth, optical density, optical conductivity and electrical conductivity are investigated and the obtained results are compared with post shock wave loaded benzil crystal with the incident light possessing wavelength at 700 nm. The results are found to be very impressive for the shock wave recovery experiments that are to be clearly discussed.

    关键词: Transmission,Shock Waves,Re-crystallization,Benzil crystal,Optical properties

    更新于2025-09-23 15:23:52

  • Rephasing efficiency of sequences of phased pulses in spin-echo and light-storage experiments

    摘要: We investigate the rephasing efficiency of sequences of phased pulses for spin echoes and light storage by electromagnetically induced transparency (EIT). We derive a simple theoretical model and show that the rephasing efficiency is very sensitive to the phases of the imperfect rephasing pulses. The obtained efficiency differs substantially for spin echoes and EIT light storage, which is due to the spatially retarded coherence phases after EIT light storage. Similar behavior is also expected for other light-storage protocols with spatial retardation or for rephasing of collective quantum states with an unknown or undefined phase, e.g., as relevant in single-photon storage. We confirm the predictions of our theoretical model by experiments in a Pr3+:Y2SiO5 crystal.

    关键词: phased pulses,rephasing efficiency,electromagnetically induced transparency,light storage,EIT,spin echoes,Pr3+:Y2SiO5 crystal

    更新于2025-09-23 15:23:52

  • High throughput MOVPE and accelerated growth rate of GaAs for PV application

    摘要: We present the feasibility of metalorganic vapor phase epitaxy (MOVPE) with extremely high-speed growth of GaAs for solar cell applications. The growth rate was increased up to 120 μm/h, and exhibited an almost linear relationship with the amount of supplied trimethylgallium (TMGa). The thickness variation and doped carrier concentration of GaAs grown at 90 μm/h were comparable to those of conventionally grown GaAs at a lower growth rate. The potential for reducing the V/III supply ratio was investigated to reduce the material cost. Non-doped GaAs wafers were grown at the accelerated growth rate of 90 μm/h, with various V/III ratios. The growth rate of GaAs increased by 20% when the V/III ratio was decreased from 40 to 5. In low temperature photo-luminescence (PL) measurement, significant change in PL spectra was not observed, indicating that there was no significant change in quality. The light-power conversion efficiency was almost comparable for V/III ratios from 10 to 40 whereas that at the lowest V/III ratio of 5 was degraded. Photovoltaic (PV) solar cells of GaAs were fabricated with various growth condition. It is found that the performance of the cells grown at 90 μm/h were comparable with previous results.

    关键词: A3. Metalorganic vapor phase epitaxy,B2. Semiconducting GaAs,B3. Solar cells,A1. Crystal morphology

    更新于2025-09-23 15:23:52

  • Optical response of a bilayer crystal

    摘要: We extend the recently developed classical theory for the optical response of a single-layer crystal to bilayers. We account for the interaction between the two atomic planes and the multiple reflections inside the crystals. We show how to define a global susceptibility meaningful for the bilayer crystal and how its expression varies compared to the single-layer case. We compute both the local and the macroscopic fields, which allow us to make a direct comparison with experimental data.

    关键词: local fields,bilayer crystal,optical response,susceptibility,macroscopic fields

    更新于2025-09-23 15:23:52