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- 2019
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- electropolymerization
- polyporphyrin films
- quartz crystal microbalance method
- oxygen electroreduction.
- supercontinuum generation
- Nonlinear
- photonic crystal fiber taper
- Applied Chemistry
- Optoelectronic Information Science and Engineering
- 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
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Single-crystal investigation of the proposed type-II Weyl semimetal CeAlGe
摘要： We present details of materials synthesis, crystal structure, and anisotropic magnetic properties of single crystals of CeAlGe, a proposed type-II Weyl semimetal. Single-crystal x-ray diffraction con?rms that CeAlGe forms in a noncentrosymmetric I 41md space group, in line with predictions of nontrivial topology. Magnetization, speci?c heat, and electrical transport measurements were used to con?rm antiferromagnetic order below 5 K, with an estimated magnon excitation gap of (cid:2) = 9.11 K from heat capacity and hole-like carrier density of 1.4 × 1020 cm?3 from Hall effect measurements. The easy magnetic axis is along the [100] crystallographic direction, indicating that the moment lies in the tetragonal ab plane below 7 K. A spin-?op transition to less than 1 μB /Ce is observed to occur below 30 kOe at 1.8 K in the M (H ) (H(cid:2)a) data. Small magnetic ?elds of 3 and 30 kOe are suf?cient to suppress magnetic order when applied along the a and c axes, respectively, resulting in a complex T –H phase diagram for H(cid:2)a and a simpler one for H(cid:2)c.
关键词： Weyl semimetal,CeAlGe,electrical transport measurements,single-crystal x-ray diffraction,antiferromagnetic order,magnetization,specific heat
更新于2025-09-04 15:30:14
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The Sommerfeld ground-wave limit for a molecule adsorbed at a surface
摘要： Using a mid-infrared emission spectrometer based on a superconducting nanowire single-photon detector (SNSPD), we observe the dynamics of vibrational energy pooling of CO adsorbed at the surface of a NaCl crystal. After exciting a majority of the CO molecules to their first vibrationally excited state (v = 1), we observe infrared emission from states up to v = 27. Kinetic Monte Carlo simulations show that vibrational energy collects in a few CO molecules at the expense of those up to eight lattice sites away by selective excitation of NaCl’s transverse phonons. The vibrating CO molecules behave like classical oscillating dipoles, losing their energy to NaCl lattice-vibrations via the electromagnetic near-field. This is analogous to Sommerfeld’s description of the Earth’s influence on radio transmission by ground waves.
关键词： vibrational energy pooling,NaCl crystal,superconducting nanowire single-photon detector,electromagnetic near-field,Kinetic Monte Carlo simulations,Sommerfeld ground-wave limit,CO adsorbed
更新于2025-09-04 15:30:14
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[IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Ku-Band Liquid-Crystal-Based Frequency Reconfigurable Comb SIW Slot Leaky-Wave Antenna
摘要： In this paper, based on liquid crystal anisotropy characteristics, a kind of frequency reconfigurable comb substrate integrate waveguide slot leaky-wave antenna use liquid-crystal-based is proposed at Ku band. It adopt comb shape and defected ground structure to compose comb SIW’s top and bottom. The slots are etched at top and bottom surface. The resonant point of propose antenna move from 15.85GHz to 14.37GHz, the tunable range is 1.5GHz by changing liquid crystal’s permittivity. Return loss less than -30dB at resonant point and the maximum gain is 8.79dB. The bandwidth of proposed antenna is 1 GHz. All the results show the reconfigurable of proposed antenna is good.
关键词： leaky-wave antenna,reconfigurable,comb substrate integrate waveguide,liquid crystal
更新于2025-09-04 15:30:14
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Synthesis, Growth and Characterization of Nonlinear Optical Ce-Doped L-Prolinium Picrate Single Crystals
摘要： A non-linear optical material L-prolinium picrate and cerium doped L-prolinium picrate were synthesized and grown as single crystals by slow evaporation method. The grown crystals were subjected to structural, elemental, thermal, optical and dielectric studies. The structural analysis reveals that pure L-prolinium picrate and Ce doped L-prolinium picrate belongs to the monoclinic crystallographic system with space group P21. Optical transparency of the grown crystals was investigated by UV-visible-NIR spectrum. The thermal analyses reveal that Ce doped L-prolinium picrate is thermally stable up to 162 °C. The dielectric constant and dielectric loss of the crystals were studied as a function of frequency. The non-linear optical property of the doped crystal was confirmed by the Kurtz-powder second harmonic generation test and the result is compared with pure L-prolinium picrate. Mechanical strength of the crystals was also carried out by Vicker's micro hardness test.
关键词： X-ray diffraction,Micro hardness,Growth from solution,Semi organic compound,Non-linear optical crystal
更新于2025-09-04 15:30:14
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Studies on growth and characterization of (E)-N′-[4-(dimethylamino) benzylidene]-4-hydroxybenzohydrazide hemihydrate: a nonlinear optical material
摘要： Hydrazone compound (E)-N′-[4-(dimethylamino) benzylidene]-4-hydroxybenzohydrazide hemihydrate (DMABHBH) was synthesized and single crystals of DMABHBH were grown by solvent evaporation method at room temperature. Molecular structure of DMABHBH compound was confirmed by 1H and 13C nuclear magnetic resonance techniques. The presence of functional groups was confirmed by Fourier transform infrared and FT Raman spectral analyses. The X-ray crystal structure was elucidated at 173 K by single crystal X-ray diffraction and the results were compared with the corresponding values obtained at 298 K. The compound crystallizes in the chiral monoclinic space group P21. Mechanical stability of the grown crystals was estimated from the Vicker’s microhardness test. Powder second harmonic generation efficiency of DMABHBH is about 1.1 times that of potassium dihydrogen phosphate. DMABHBH is found to show optical limiting behavior at high input light intensities, the third order nonlinear optical absorption coefficient measured using open aperture Z-scan studies, is 0.95 × 10?11 m/W. Anti-bacterial activity was studied using the well and disc diffusion methods.
关键词： X-ray diffraction,Mechanical properties,Nonlinear optical material,Thermal analysis,Antibacterial activity,Hydrazone,Crystal growth
更新于2025-09-04 15:30:14