We use inelastic neutron scattering (INS) to study the spin excitations in partially detwinned NaFe0.985Co0.015As which has coexisting static antiferromagnetic (AF) order and superconductivity (Tc=15 K, TN=30 K). In p...
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We use inelastic neutron scattering (INS) to study the spin excitations in partially detwinned NaFe0.985Co0.015As which has coexisting static antiferromagnetic (AF) order and superconductivity (Tc=15 K, TN=30 K). In previous INS work on a twinned sample, spin excitations formed a dispersive sharp resonance near Er1=3.25 meV and a broad dispersionless mode at Er1=6 meV at the AF ordering wave vector QAF=Q1=(1,0) and its twinned domain Q2=(0,1). For partially detwinned NaFe0.985Co0.015As with the static AF order mostly occurring at QAF=(1,0), we still find a double resonance at both wave vectors with similar intensity. Since Q1=(1,0) characterizes the explicit breaking of the spin rotational symmetry associated with the AF order, these results indicate that the double resonance cannot be due to the static and fluctuating AF orders but originate from the superconducting gap anisotropy.
NiTi shape memory alloy was modified by Ag ion implantation with different incident doses to improve its antibacterial property. The atomic force microscopy, auger electron spectroscopy, and X-ray photoelectron spectr...
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NiTi shape memory alloy was modified by Ag ion implantation with different incident doses to improve its antibacterial property. The atomic force microscopy, auger electron spectroscopy, and X-ray photoelectron spectroscopy show that the surface of NiTi alloy is covered by TiO2 nano-film with embedded pure Ag with a peak concentration of 5.0 at% at the incident dose of 1.5 x10^17 ***-a, and Ni concentration is reduced in the super- ficial surface layer. The surface roughness reaches the maximum value nearly twice higher than the control sample at the incident dose of 1.5x10^17 ***-2. The potentiodynamic anodic polarization curves show that the Ag-implanted NiTi samples possess higher self-corrosion potential （Ecorr） and lower self-corrosion current density （icor0 but lower breakdown potential （Ebr）. Therefore, the corrosion resistance of the Ag-NiTi is comparable to, if not better than, the untreated NiTi. The antibacterial tests reveal that there is a distinct reduction of the germ numbers on the Ag-NiTi, which is due to the direct contact between Ag and germ, and enhanced by the leaching Ag ions.
The rare earth Pr doped Ca1-xPrxMnO3 （x=0, 0.06, 0.08, 0.1, 0.12, and 0.14） compound bulk samples were prepared to study the effect of Pr doping on thermoelectric transport properties of CaMnO3 compound system. The ...
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The rare earth Pr doped Ca1-xPrxMnO3 （x=0, 0.06, 0.08, 0.1, 0.12, and 0.14） compound bulk samples were prepared to study the effect of Pr doping on thermoelectric transport properties of CaMnO3 compound system. The doped samples exhibited sin-gle phase composition within the experimental doping range, with condensed bulk microstructure and small porosities. The electrical resistivity was remarkably reduced for doped samples, on account of the enhanced carrier concentration;the absolute value of See-beck coefficient was deteriorated mainly due to enhanced electron carrier concentration. The electrical performances of the doped samples reflected by resistivity and Seebeck coefficient fluctuations were optimistically tuned, with an optimized power factor value of 0.342 mW/（m·K2） at 873 K for x=0.08 sample, which was very much higher comparing with that of the un-doped sample. The lattice thermal conduction was really confined, leading to distinctly repressed total thermal conductivity. The thermoelectric per-formance was noticeably improved by Pr doping and the dimensionless figure of merit ZT for the Ca0.92Pr0.08MnO3 compound was favorably optimized with the maximum value 0.16 at 873 K.
This paper highlights our work on the recent progress in novel elastico-mechanoluminescence(EML)materials CaZnOS:Mn^(2+)and CaZr(PO_(4))_(2):Eu ^(2+),which can simultaneously"feel"(sense)and"see"(i...
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This paper highlights our work on the recent progress in novel elastico-mechanoluminescence(EML)materials CaZnOS:Mn^(2+)and CaZr(PO_(4))_(2):Eu ^(2+),which can simultaneously"feel"(sense)and"see"(image)the applied mechanical stress as an intense and proportional ***:Mn 2þcan sense various types of mechanical stress,including ultrasonic vibration,impact,friction and compression because of the large piezoelectric ***(PO_(4))_(2):Eu ^(2+)with multiple trap levels shows a broad measurement range for dynamic *** of CaZnOS:Mn^(2+)and CaZr(PO_(4))_(2):Eu ^(2+)belong to the defect-controlled type pie-zoelectric phosphors,and their EML mechanisms could be explained using the piezoelectrically induced carrier de-trapping model.
HT-350RTM, a novel high temperature polyimide resin for resin transfer molding (RTM) process, was synthesized through an optimized proportion of diamine monomer. 4-phenylethynylphthalic anhydride (4-PEPA) was employed...
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HT-350RTM, a novel high temperature polyimide resin for resin transfer molding (RTM) process, was synthesized through an optimized proportion of diamine monomer. 4-phenylethynylphthalic anhydride (4-PEPA) was employed as the end-capping agent of HT-350RTM resin, and 2, 3, 3', 4'-biphenyltetracarboxylic dianhydride (α-BPDA) used as its dianhydride monomer. U3160/HT-350RTM laminates were fabricated by RTM process reinforced by U3160 carbon fabric for evaluation of mechanical properties. The results show that the lowest melt viscosity of HT-350RTM is 390 mPa·s, and it stays below 1 Pa·s for over 2 h at 280°C, which qualifies the possibility for RTM process. After being cured, the glass transition temperature is 392°C and the decomposition temperature (5% loss) is 537°C. The porosity of U3160/HT-350RTM laminates is only 0.34%. The U3160/HT-350RTM composites exhibit excellent mechanical properties at room temperature, and the retention rates of mechanical properties at 315°C and 350°C are both more than 60%, making the U3160/HT-350RTM composites ideal for the long-term use under 350°C.
Zinc oxide is a wide bandgap semiconductor of great interest for optoelectronic devices, transparent electronics, spintronic devices and sensor applications [1]. Variously shaped ZnO nanowires and nanorods are routine...
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Zinc oxide is a wide bandgap semiconductor of great interest for optoelectronic devices, transparent electronics, spintronic devices and sensor applications [1]. Variously shaped ZnO nanowires and nanorods are routinely synthesized, and their electrical and optical properties have been exploited for many exciting applications [2]. ZnO nanostructures offer new and enhanced properties that differ from the bulk and thin film
A method combining the evaluation of dynamic stress distribution and ultrasonic wave propagation analysis for composite materials is presented. By using two-dimensional time domain finite element analysis, a bimateria...
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A method combining the evaluation of dynamic stress distribution and ultrasonic wave propagation analysis for composite materials is presented. By using two-dimensional time domain finite element analysis, a bimaterial composite with elliptical defect is established. Based on elastic wave propagation, the deformation and scattering wave fields against different material properties are presented. The stress concentration at free edge and interface and influence of defect on the dynamic stress distribution are investigated. The simulation results show that ultrasonic wave propagation analysis is convenient and effective way to evaluate the interaction, stress singularities and internal stress distribution in the composite materials.
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