Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
ABSTRACT The present study focuses on the effect of microstructural gradients on the fatigue crack growth resistance of Ti‐6Al‐4V and Ti‐6242 titanium alloys. Sharp microstructural gradients from fine‐grained bimodal to coarse‐grained lamellar microstructures were obtained by heat treating only a portion of fine‐grain…
A phase-field model for investigating the surface morphological evolution of a film is developed, taking into account the surface energies of film and substrate, the interfacial energy between the film and substrate, and the elastic energy associated with the lattice mismatch between the film and substrate. Using the…
Elastic constants and the Poisson ratio of the fcc hard-sphere crystalline phases, free of defects and with vacancies, are determined by two Monte Carlo methods: (i) the analysis of the box fluctuations in the constant pressure ensemble with variable box shape (N-P-T) and (ii) by the free-energy differentiation with r…
We report colossal magnetoresistance at room temperature by introducing disorder to the A-site ordered manganites, SmBaMn2O6. SmBaMn2O6 shows the metal to CE-type charge/orbital ordered insulator transition at 375K above room temperature. We have achieved a magnetoresistance effect of 340% at room temperature and 300%…
Alkyl-modified silicon nanocrystallites are efficient fluorophores which are of interest for fundamental spectroscopic studies and as luminescent probes in biology because of their stability in aqueous media. In this work we have investigated these particles using scanning tunneling microscopy, synchrotron-radiation e…
Room-temperature ferromagnetic In1−xCrxN films with x ranging from 0.0005 to 0.04 and antiferromagnetic CrN films have been grown by plasma-assisted molecular-beam epitaxy. Electron and x-ray-diffraction techniques could find no evidence for precipitates or phase segregation within the films. Ferromagnetism was observ…
While the swelling behavior of laboratory-prepared homoionic montmorillonites has been studied extensively in numerous experimental and simulation works, far less attention has been given to much more abundant natural montmorillonites, containing a mix of monovalent and/or bivalent cations in interlayer spaces. We car…
We observed a significant enhancement of electric resistivity excited by a dc current in ${\mathrm{La}}_{0.8}{\mathrm{Ca}}_{0.2}{\mathrm{MnO}}_{3}$ epitaxial thin films. Such an enhanced resistance can be achieved when the applied dc current exceeds a threshold value. It also strongly depends on the duration of the dc…
We have measured the temperature-dependent thermal conductivity κ(T) of boron-carbon-nitride (B-C-N) and boron nitride (BN) nanotube mats. The thermal conductivity of B-C-N nanotubes is phonon dominated and reflects dimensional effect below 70 K. We employ a new analysis method to estimate the intrinsic κ(T) of BN nan…
The effect of TiO2 doping on the structure and magnetic and magnetotransport properties of La0.75Sr0.25MnO3 (LSMO)∕xTiO2 has been investigated. These studies show that at low doping level (x⩽2) TiO2 mainly goes into the grain-boundary region, but at high doping level (x⩾3), some part of the TiO2 goes into the perovski…
Miniaturized planar solid-oxide fuel cells (SOFCs) and stacks can be fabricated by thin film deposition and micromachining. Serious thermal stresses, originating in fabrication and during operation, cause thermal–mechanical instability of the constituent thin films. In this paper, the effect of thin film geometry on t…
The Ni2MnGa-based Heusler alloys with high magnetocaloric effect have attracted considerable attention as a promising magnetic refrigerant. The phase-transition processes and magnetic entropy changes in the NiMnGa alloys with the concurrence of magnetic and structural phase transitions were studied. The ac magnetic su…
We theoretically show that the Goos-Hänchen (GH) shifts [F. Goos and H. Hänchen, Ann. Phys. 1, 333 (1947)] of the TE- and TM-polarized beams reflected from a slab of the weakly absorbing left-handed material can be large positive near the resonant transmission if the absorption of the slab is sufficiently weak. The GH…
We study the rheology of model colloidal suspensions using molecular-dynamics simulations. We relate the onset of shear thickening to the transition from a low-viscosity regime, in which the solvent facilitates the flow of colloids, to a high-viscosity regime associated with jamming of the colloids and the formation o…
The flexibility in the material selection for polymer composite sandwich structures in naval ship applications provides opportunities to optimize properties for various requirements. However, this freedom comes with a price in terms of increased complexity. This study presents considerations in the material selection…
Abstract Several new glycols containing both imide and sulfone groups, sulfonyl bisimide glycol (SBIG), were prepared from primary aromatic diamine, trimellitic anhydride and excess low molecular glycols. Then these SBIGs were used as chain extender to prepare a series of thermoplastic poly(imide‐urethane) (PIU), whic…
We report the experimental result of the specific contact resistance (ρ c ) of porous silicon and silver metal Ohmic contact structure formed on the n + region (doped with phosphorous atoms) to boron-doped p-type single crystalline silicon. The contact structure consists of sintered Ag metal grid contact on a porous s…
The figure of merit ZT is measured by a Harman method on simple devices prepared on single thermoelectric layers of different thicknesses. The thermoelectric layers are prepared at different conditions by laser ablation from Bi2Te3 target. The best measured figure of merit ZT is for our devices ZT=2.65. This result is…
Fast-response, polarization-independent, and hysteresis-free phase-only modulation using a normal-mode polymer-stabilized cholesteric texture (PSCT) is demonstrated. Although the remaining phase change in the high-voltage regime is small, it is still useful for making microdevices. Polarization-independent tunable-foc…
Vapor phase grown ZnO samples treated with hydrogen and∕or deuterium plasma were studied by means of photoconductivity and infrared (IR) absorption spectroscopy. Three bands at 180, 240, and $310\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$ were observed in the photoconductivity spectra of hydrogenated Z…