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。
The process of aging in rubbers requires monitoring over long periods (days to years). To do so in nonconducting rubbers, small amounts of carbon-black particles were dispersed in a fractal network through the rubber matrix, to make the rubber conducting without modifying its properties. Continuous monitoring of the r…
We show that geometric confinement dramatically affects the shear-induced configurations of dense monodisperse colloidal suspensions; a new structure emerges, where layers of particles buckle to stack in a more efficient packing. The volume fraction in the shear zone is controlled by a balance between the viscous stre…
Bulk metallic glass forms when liquid metal alloys solidify without crystalization. In the search for Iron-based bulk glass-forming alloys of the metal-metalloid type (Fe-B- and Fe-C-based), crystals based on the structural prototype C6Cr23 often preempt the amorphous phase. Destabilizing this competing crystal struct…
We have performed specific heat and electric resistivity measurements of Na$_{x}$CoO$_{2}$ ($x=0.70$-0.78). Two anomalies have been observed in the specific heat data for $x=0.78$, corresponding to magnetic transitions at $T_{c}=22$ K and $T_{k}\simeq 9$ K reported previously. In the electrical resistivity, a steep de…
Powder Na$_{x}$CoO$_{2}$ ($0.70\leq x\leq 0.84$) samples were synthesized and characterized carefully by X-ray diffraction analysis, inductive-coupled plasma atomic emission spectroscopy, and redox titration. It was proved that $γ$-Na$_{x}$CoO$_{2}$ is formed only in the narrow range of $0.70\leq x\leq 0.78$. Neverthe…
We present an analysis of the structure of the fluctuation-induced microemulsion phase in a ternary blend of balanced AB diblock copolymers with equal amounts of A and B homopolymers. To this end, graphical analysis methods are employed to characterize two-dimensional configuration snapshots obtained with the recently…
The strength and effect of Coulomb correlations in the (superconducting when hydrated) x~1/3 and ``enhanced'' x~2/3 regimes of Na(x)CoO2 are evaluated using the correlated band theory LDA+U method. Our results, neglecting quantum fluctuations, are: (1) allowing only ferromagnetic order, there is a critical U_c = 3 eV,…
Electrical conductivity of porous silicon fabricated from heavily doped p-type silicon is very sensitive to NO2, even at concentrations below 100ppb. However, sensitivity depends strongly on the porous microstructure. The structural difference between sensitive and insensitive samples is independently confirmed by mic…
The molecular dynamics method, based on an empirical potential energy surface, was used to study the effect of catalyst particle size on the growth mechanism and structure of single-walled carbon nanotubes (SWNTs). The temperature for nanotube nucleation (800-1100 K), which occurs on the surface of the cluster, is sim…
Topological phase imprinting is a unique technique for vortex formation in a Bose-Einstein condensate (BEC) of alkali metal gas, in that it does not involve rotation: BEC is trapped in a quadrupole field with a uniform bias field which is reversed adiabatically leading to vortex formation at the center of the magnetic…
The orthorhombic structure of (Na 0.5 K 0.5 )NbO 3 (NKN) ceramics was maintained when ZnO was added. NKN ceramics have a porous microstructure and dissolve when they are exposed to water. However, as ZnO was added, a dense microstructure was developed and deliquescence was not observed. The mechanical quality factor (…
A polarized Raman study of nanographite ribbons on a highly oriented pyrolytic graphite substrate is reported. The Raman peak of the nanographite ribbons exhibits an intensity dependence on the light polarization direction relative to the nanographite ribbon axis. This result is due to the quantum confinement of the e…
We present results of the electro-optical effect in 90° twisted nematic cells of pristine and doped liquid crystals under an applied dc voltage. The doped cells were fabricated with a minute addition of either buckminsterfullerene C60 or multiwalled carbon nanotubes (CNTs). Investigated were the switching behaviors as…
Radiative and energy-transfer processes in LiGd 1 - x F 4:Eu 3+ x, where the ground state of Gd 3+ ( 8 S 7/2 ) was selectively excited to the 6 I J state by a 275-nm pulsed laser irradiation, were studied by time-resolved luminescence spectroscopy. Two decay components were observed in Gd 3+: 6 P 7/2 → 8 S 7/2 emissio…
Abstract The scope of this paper is to continue our earlier study of the peroxide curing of elastomers derived from butadiene. Experimental evidence indicates that abstraction of allylic hydrogen and addition to the double bonds can act as a mechanism for cross‐linking. The addition reaction may give rise to a polymer…
Abstract Polysilsesquioxane with phenyl and chloromethylphenyl groups (PCPSQ) was prepared readily from phenyltrimethoxysilane and [2‐(chloromethylphenyl)ethyl]trimethoxysilane under acidic conditions. Polymerization with chloromethylphenyl groups on PCPSQ with methyl methacrylate (MMA) was conducted in the presence o…
Abstract Three new organically templated polyoxomolybdates with selenite anions as capping groups have been synthesized by hydrothermal reactions and structurally characterized. The structure of {Hbipy} 3 {KMo 4 O 13 (SeO 3 )} ( 1 ; bipy = 4,4′‐bipyridine) features a 1D anionic double chain of {KMo 4 O 13 (SeO 3 )} 3−…
Polyvinyl alcohol-hydrogels (PVA-H) have been specifically proposed as promising prosthetic biomaterials because of their excellent mechanical properties and biocompatibility. However, it is very difficult to obtain stable long-term fixation of implanted PVA-H and this problem is the key point to be solved in the furt…
A family of amorphous, solid-solution magnets of V x Fe 1 - x [TCNE] 2 · z CH 2 Cl 2 (TCNE = tetracyanoethylene; 0 ≤ x ≤ 1) composition has been characterized by IR spectrometry, elemental analysis, and magnetic measurements (ac and dc susceptibility). Substitution of Fe II for V II in V[TCNE] 2 · z CH 2 Cl 2 does not…
The decomposition of methane into carbon and hydrogen over 15 mol % MnO x /20 mol %NiO/TiO 2 catalysts was investigated. The effects of catalyst synthesis and pretreatment of 15 mol % MnO x /20 mol % NiO/TiO 2 catalysts for the activity and morphology of carbon from methane decomposition were identified, based on the…