The superconducting and normal-state properties of La1−xSmxO0.5F0.5BiS2 (0.1≤x≤0.9) have been studied via electrical resistivity, magnetic susceptibility, and specific heat measurements. By using suitable synthesis ...
The superconducting and normal-state properties of La1−xSmxO0.5F0.5BiS2 (0.1≤x≤0.9) have been studied via electrical resistivity, magnetic susceptibility, and specific heat measurements. By using suitable synthesis conditions, Sm exhibits considerable solubility into the CeOBiS2-type LaO0.5F0.5BiS2 lattice. In addition to a considerable enhancement of the superconducting volume fraction, it is found that the superconducting transition temperature Tc is dramatically enhanced with increasing Sm concentration to 5.4 K at x=0.8. These results suggest that Tc for SmO0.5F0.5BiS2 could be as high as ∼6.2 K, and comparably high Tc values might also be obtained in the compounds LnO0.5F0.5BiS2 (Ln=Eu−Tm) if they can be synthesized.
We present a methodology to enhance the electrical capacitance of activated carbon (AC) electrodes based on the introduction of electrically charged defects through argon plasma processing. Extensive characterization ...
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We present a methodology to enhance the electrical capacitance of activated carbon (AC) electrodes based on the introduction of electrically charged defects through argon plasma processing. Extensive characterization using electrochemical techniques incorporating cyclic voltammetry, constant current charge/discharge, and electrical impedance spectroscopy indicated a close to seven-fold increase in capacitance with respect to untreated AC electrodes, not subject to plasma processing.
Electrical resistivity measurements on La1−xSmxO0.5F0.5BiS2(x=0.1,0.3,0.6,0.8) have been performed under applied pressures up to 2.6 GPa from 2 K to room temperature. The superconducting transition temperature Tc of e...
Electrical resistivity measurements on La1−xSmxO0.5F0.5BiS2(x=0.1,0.3,0.6,0.8) have been performed under applied pressures up to 2.6 GPa from 2 K to room temperature. The superconducting transition temperature Tc of each sample significantly increases at a Sm-concentration-dependent pressure Pt, indicating a pressure-induced phase transition from a low-Tc to a high-Tc phase. At ambient pressure, Tc increases dramatically from 2.8 K at x=0.1 to 5.4 K at x=0.8; however, the Tc values at P>Pt decrease slightly with x, and Pt shifts to higher pressures with Sm substitution. In the normal state, semiconducting-like behavior is suppressed, and metallic conduction is induced with increasing pressure in all of the samples. These results suggest that the pressure dependence of Tc for the BiS2-based superconductors is related to the lattice parameters at ambient pressure and enable us to estimate the evolution of Tc for SmO0.5F0.5BiS2 under pressure.
In this talk, I will discuss our recent efforts to develop purely dielectric metamaterials possessing low absorption loss at optical frequencies. I will discuss implementations ranging from wavefront control to high Q...
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ISBN:
(纸本)9781467371100
In this talk, I will discuss our recent efforts to develop purely dielectric metamaterials possessing low absorption loss at optical frequencies. I will discuss implementations ranging from wavefront control to high Q-factor resonances.
In this report, an atom efficient and facile synthetic strategy for accessing multi-diketopyrrolopyrrole (DPP)-based oligomers used in solution-processed organic field effect transistors (OFETs) and organic solar cell...
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Adding colloidal nanoparticles into liquid‐crystal media has become a promising pathway either to enhance or to introduce novel properties for improved device performance. Here we designed and synthesized new colloid...
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Adding colloidal nanoparticles into liquid‐crystal media has become a promising pathway either to enhance or to introduce novel properties for improved device performance. Here we designed and synthesized new colloidal hybrid silica nanoparticles passivated with a mesogenic monolayer on the surface to facilitate their organo‐solubility and compatibility in a liquid‐crystal host. The resulting nanoparticles were identified by 1 H NMR spectroscopy, TEM, TGA, and UV/Vis techniques, and the hybrid nanoparticles were doped into a dual‐frequency cholesteric liquid‐crystal host to appraise both their compatibility with the host and the effect of the doping concentration on their electro‐optical properties. Interestingly, the silica‐nanoparticle‐doped liquid‐crystalline nanocomposites were found to be able to dynamically self‐organize into a helical configuration and exhibit multi‐stability, that is, homeotropic (transparent), focal conic (opaque), and planar states (partially transparent), depending on the frequency applied at sustained low voltage. Significantly, a higher contrast ratio between the transparent state and scattering state was accomplished in the nanoparticle‐embedded liquid‐crystal systems.
True triaxial tests have been carried out in two quartz-rich, high porosity, sandstones, Coconino (n = 17.5%) and Bentheim (n = 24%) by maintaining constant but different σ2 and σ3 and raising σ1 until failure occu...
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ISBN:
(纸本)9781634395236
True triaxial tests have been carried out in two quartz-rich, high porosity, sandstones, Coconino (n = 17.5%) and Bentheim (n = 24%) by maintaining constant but different σ2 and σ3 and raising σ1 until failure occurred (at σ1,peak). For each constant σ3 level, σ2 was varied from test to test between σ2 - σ3 and σ2 = σ1, σ1,peak for a given σ3 increased with σ2, reached a maximum (up to 15% higher than when σ2 = σ3), and then declined so that when σ1 approached σ1, σ1,peak was about equal to its base value when σ2 = σ3. A separate series of tests was carried out using a novel loading path by maintaining constant Lode angle θ (= 0°). This series of tests characterized the dependence of the octahedral shear stress at failure τoct,f on the octahedral normal stress at failure σoct,f when θ = 0°. The latter tests were used to obtain the necessary parameters employed in a three-invariant failure theory proposed by Rudnicki (2013). The theory was then applied to predicting the variation of σ1,peak with σ2 for a given σ3. The prediction reasonably replicated the typical ascending-then-descending σ1,peak vs. σ2 trend observed experimentally in both sandstones, confirming (with some limitations) the applicability of the Rudnicki's (2013) theory. Copyright (2014) ARMA, American Rock Mechanics Association
Flexible lithium‐ion batteries are critical for the next‐generation electronics. However, during the practical application, they may break under deformations such as twisting and cutting, causing their failure to wo...
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Flexible lithium‐ion batteries are critical for the next‐generation electronics. However, during the practical application, they may break under deformations such as twisting and cutting, causing their failure to work or even serious safety problems. A new family of all‐solid‐state and flexible aqueous lithium ion batteries that can self‐heal after breaking has been created by designing aligned carbon nanotube sheets loaded with LiMn 2 O 4 and LiTi 2 (PO 4 ) 3 nanoparticles on a self‐healing polymer substrate as electrodes, and a new kind of lithium sulfate/sodium carboxymethylcellulose serves as both gel electrolyte and separator. The specific capacity, rate capability, and cycling performance can be well maintained after repeated cutting and self‐healing. These self‐healing batteries are demonstrated to be promising for wearable devices.
The aim was to investigate particles of poly (methylmethacrylate) (PMMA) prepared by suspension polymerization using different concentration of a stabilizer and by varying of the agitation speed at 300, 400, and 500 r...
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