摘要 :
The single fibre pull-out test is one of the major mesomechanical methods which are designed to measure the interface properties between the fiber and matrix in composites. An axisymmetrical boundary element method is used for the...
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The single fibre pull-out test is one of the major mesomechanical methods which are designed to measure the interface properties between the fiber and matrix in composites. An axisymmetrical boundary element method is used for the single fibre composite model to obtain the stress distributions at the fibre-matrix interface. The numerical results show that the interface radial and shear stress components, σr and τrz, are singular at the fiber entry and the embedded fiber end, and vary linearly with the axial distance, z, in a log-log plot.
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摘要 :
Via a specially widened anodic aluminum oxide (AAO) pore arrays, carbon nanodot arrays with uniform size and high density were obtained through filtered cathodic arc plasma (FCAP) technique. The AAO template was prepared in oxalic...
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Via a specially widened anodic aluminum oxide (AAO) pore arrays, carbon nanodot arrays with uniform size and high density were obtained through filtered cathodic arc plasma (FCAP) technique. The AAO template was prepared in oxalic acid by multi-steps to get a specially enlarged opening which plays an important role in the deposition of nanodots. The morphology of the nanodots was studied by a field emission scanning electron microscopy (FESEM). The diameter of the as-prepared nanodot demonstrated here is about 100 nm at the bottom and less than 40 nm at the top, and the density was estimated to 10~(10) cm~(-2). Field emission properties of the nanodot arrays were investigated and a low threshold field of 5.1 V/μm at 10 mA/cm~2 was obtained. In this paper, the carbon nanodot arrays grown as replicas of the specially widened AAO template may support a strategy to realize the fabrication of nanodot arrays with various materials.
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摘要 :
A hydrothermal nanoparticle-plating technique has been employed in order to grow a layer of CoSb_3 nanoparticles on the surface of La_(0.9)CoFe_3Sb_(12) bulk matrix grains. The nanoparticles have a typical size of 30-40 nm while t...
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A hydrothermal nanoparticle-plating technique has been employed in order to grow a layer of CoSb_3 nanoparticles on the surface of La_(0.9)CoFe_3Sb_(12) bulk matrix grains. The nanoparticles have a typical size of 30-40 nm while the nano-layer can be up to several hundreds of nanometer thick. The nanoparticle layer, which resides at the grain boundary after hotpressing, provides an extra scattering channel for phonons, in addition to the "rattler" atoms (La), grain boundary scattering, and mass fluctuation mechanisms found within the bulk matrix grain. The electrical resistivity, thermopower, thermal conductivity, and Hall coefficient have been investigated as a function of temperature and the weight percentage (%) of nanoparticles. Largely due to the reduced lattice thermal conductivity, a ZT value of ～0.5 is attained at 725 K on the sample with 5 wt % of nanoparticles showing a 15% improvement of the ZT from that of the sample without nanoparticles and comparable to the best value reported at this temperature.
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摘要 :
A series of Bi_2Te_3 nanocomposite samples have been prepared by incorporating nanoparticle concentrations of 5-50 mol % into a bulk matrix via a mixing process and subsequently hot pressing into highly densified pellets. The elec...
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A series of Bi_2Te_3 nanocomposite samples have been prepared by incorporating nanoparticle concentrations of 5-50 mol % into a bulk matrix via a mixing process and subsequently hot pressing into highly densified pellets. The electrical resistivity, therm
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