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。
We examine two aspects of Stockmayer fluids which consists of point dipoles that additionally interact via an attractive Lennard-Jones potential. We perform Monte Carlo simulations to examine the effect of an applied field on the liquid-gas phase coexistence and show that a magnetic fluid phase does exist in the absen…
Enzymes are thought to use their ordered structures to facilitate catalysis. A corollary of this theory suggests that enzyme residues involved in function are not optimized for stability. We tested this hypothesis by mutating functionally important residues in the active site of T4 lysozyme. Six mutations at two catal…
In the present study magnetic and magnetostrictive properties of Tb(Fe1−xTx)2 (T=Mn, Ga) compounds were examined by magnetic measurement, Mössbauer, and x-ray study. Mössbauer study shows that the easy magnetization direction of the compounds may deviate slightly from the major axis of symmetry and the average isomer…
Na2Ti3Cl8 is a temperature-dependent magnetic switch. The switching process (= phase transition) takes places below room temperature and is accompanied by a drastic decrease in magnetic susceptibility and molar volume. The transition is attributed to the formation of [Ti3]6+ clusters (see diagram) by two-dimensional P…
Scanning tunneling microscopy (STM) and tunneling spectroscopy have been used to investigate the local structural and electronic properties of boron-induced reconstructions on Si(001). Thermal decomposition of diborane produces three ordered reconstructions, which arise from ordered arrangements of three structural su…
The thermoelectric power S of GeTe-rich (GeTe)1-x(Bi2Te3)x solid solutions (0 ≦ x ≦ 0.05) is investigated as a function of composition x and temperature T in the range from 80 to 350 K, where the materials have the crystal and band structure of the rhombohedral α-phase of GeTe. On the basis of the non-parabolic two-ba…
Metal colloids in CaF2 created by low energy electron irradiation are identified by their optical absorption bands. A mean colloid radius of 18 nm is deduced from a narrow colloid band found in crystals irradiated at room temperature. Absorption data reveal a strong influence of crystal temperature during irradiation…
Using conventional and high resolution transmission electron microscopy, the dislocation structures in PbTiO3 thin films grown epitaxially on [001]-oriented MgO and SrTiO3 single crystals are studied. High resolution cross-sectional images of the films grown on MgO exhibit misfit dislocations with Burgers vectors of 1…
The phosphorylation of bovine tau, either by GSK-3 alone or by a combination of GSK-3 and several non-proline-dependent protein kinases (non-PDPKs), was studied. GSK-3 alone catalyzed the incorporation of approximately 3 mol 32P/mol tau at a relatively slow rate. Prephosphorylation of tau by A-kinase, C-kinase, or CK-…
Nanostructures through self-assembly: Suitably designed planar cyclic peptides like 1 form cylindrical dimers in nonpolar organic solvents. These ensembles are good models for the fundamental description of parallel and antiparallel β-sheet structures as well as for the design of novel peptide nanostructures. The anal…
A large magnetoresistance ratio in excess of 10 000% (at 140 K, H=6 T) has been obtained in a sintered perovskitelike material with a composition of La0.60Y0.07Ca0.33MnOx. The doping of La–Ca–Mn–O with Y resulted in a decrease in the lattice parameter by ∼0.2%, and improved the magnetoresistance by an order of magnitu…
The angular distributions of $1s\ensuremath{\sigma}$ photoelectrons from ${\mathrm{N}}_{2}$ molecules held fixed in space have been measured around the ${\ensuremath{\sigma}}^{*}$ shape resonance for the first time. The angular distributions have been very rich in structure, which are completely different from usual p…
The tracer diffusion coefficients ${D}^{*}$ of polystyrene (PS) chains near PS melt-solid interfaces have been measured by secondary ion mass spectrometry. The ${D}^{*}$ for poly(2-vinylpyridine) (PVP) and oxide (SiO) covered silicon surfaces were smaller by, respectively, \ensuremath{\sim}3 and \ensuremath{\sim}${10}…
Nanostructures through self-assembly: Suitably designed planar cyclic peptides like 1 form cylindrical dimers in nonpolar organic solvents. These ensembles are good models for the fundamental description of parallel and antiparallel β-sheet structures as well as for the design of novel peptide nanostructures. The anal…
Abstract The importance of nonlinear optical phenomena has been known for some time, however, since the mid‐1980s, there has been an explosion of interest in the search for and development of non‐linear optical materials that possess commercial device applications. To date, the systems have been utilized in informatio…
Abstract A series of methyl methacrylate polymers have been prepared containing sucrose‐based crosslinkers and additives. Thermogravimetry and long‐term aging studies at 200°C show that sucrose‐based alkyl and allyl ethers provide unprecedented thermal stability to linear, as well as crosslinked, poly (methyl methacry…
In LiIO(3) and BBO crystals the wave-matching conditions for femtosecond noncollinear parametric light generation at lambda = 390 nm pumping wavelength are investigated. In the LiIO(3) crystal simultaneous phase- and group-velocity-matching angles are determined. Parametric generation occurred at 0.45-2.9-mu;m wavelen…
In order to clarify the roles of cation and anion molecules in the ferridistortive phase transition, four kinds of single crystals of [A(CH 3 ) 4 + ] 2 XBr 4 2- type, where cat-ion sites are occupied either by tetramethylphosphonium ion P(CH 3 ) 4 + or by tetramethylammonium ion N(CH 3 ) 4 + , and anion site either by…
Thermal diffusivity and conductivity of ceramic materials in a system of Si3N4-SiO2-Al2O3-AlN composed of α and β SiAlON (which is well known as duophase SiAlON ceramics) are investigated. Single-phase β-SiAlON ceramic has a thermal conductivity of 12.44 W/m K. The thermal conductivities of SiAlON ceramics decrease li…
We have observed stimulated extraordinary-ordinary wave scattering and cross-polarized self-starting optical phase conjugation effects in a nematic liquid-crystal film. The basic mechanism involved is the nonresonant laser-induced nematic crystal axis reorientation. These processes require low optical power and are ch…