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 spectrum of a charged particle in uniform magnetic field consists of equally spaced Landau levels which are infinitely degenerate. We consider isospectral deformations of this problem and show that the spectrum is again equispaced but nondegenerate for a wide class of non-uniform magnetic fields.
The theory of the synthesis of diamond by the polycondensation of light carbon-containing molecules is examined, and the optimum stoichiometric, thermodynamic, and kinetic conditions for diamond and graphite polycondensation and the reverse conversion of diamond and graphite by water vapour and carbon dioxide are desc…
Experimental data on the use of IR spectra to identify compounds formed on the surface of various supports during the deposition of heteropoly compounds are reviewed. The spectral properties of the heteropoly compounds are analysed according to their type, to the character of the central ion, and to the form of the su…
A plating process was developed to deposit Ni-P, nickel and gold on an optical glass fiber. The tensile strength of the metallized pigtail increases when the oxidation time, or the electrolytic Ni or Au layer thickness increases, or when the electroless Ni layer thickness decreases. A pull force of more than 1,000 g i…
Abstract The structure of an outer accretion disk self-irradiated by the radiation from an inner viscous accretion disk is examined. The radiating region of the inner disk is assumed to be disk-shaped. The structure of the self-irradiated accretion disk is strongly modified from the viscous accretion disk. The tempera…
An expression and mutagenesis system for the E. coli Class II fructose-1,6-bisphosphate aldolase has been created by modification of the vector pKfda (Biochem. J. 257 (1989) 529-534). Large amounts of Class II aldolase (about 1 g/l in crude extracts), with properties consistent with those previously reported for the n…
We have studied the emission spectra from plasmas excited in several compositions of three different gas mixtures useful for the growth of diamond films, namely CH4-H2 (the classical one), CH4-CO2 and C2H2-CO2 (not previously reported by other authors). In all three cases we find the same correlation between the quali…
Crystal to glass transitions are simulated using molecular dynamics for an fcc binary random solid solution with varying atomic size ratios and concentrations. The transition occurs at a critical supersaturated solute concentration with a sufficiently large solute-solvent atomic size difference. Close to the amorphiza…
The atomic and electronic structure of various Si-based layered structures is calculated using pseudopotential density-functional theory and a self-energy approach. A silicon-hydrogen compound, consisting of a stacking in the [111] direction of double layers of Si terminated with H, is found to have an almost direct b…
Langmuir monolayers and freely suspended smectic films can exhibit a spontaneous breaking of chiral symmetry. The order parameter that characterizes this symmetry breaking is coupled to variations in the direction of molecular tilt. As a result, chiral symmetry breaking leads to the spontaneous formation of complex eq…
Abstract Radiation‐induced grafting of acrylic acid onto ultrahigh molecular weight (UHMW) high‐strength polyethylene fibers to impart heat resistance and dyeability was undertaken. A preirradiation method was employed for grafting in an aqueous solution of acrylic acid containing a small amount of Mohr's salt as inhi…
New upconversion phosphor BaCl2 containing 28 mol% Er3+ exhibited extremely bright green luminescence, and the fluorescence intensity of the chloride at 550 nm and under 1.516 μm (5mW) laser diode excitation was 40 times greater than that of conventional Er3+-doped fluoride. The excitation spectrum and stability of th…
Quasi-static stress relaxation and dynamic internal friction measurements of stress induced reversible structural relaxation were performed on the amorphous alloy Fe40Ni40B20. The kinetics can be well described by a stretched exponential Kohlrausch-Williams-Watts quasi-static relaxation. The thermally activated part o…
The luminescence spectra of Y2TiO5 and Y2Ti2O7, NaSn2−xTix(PO4)3 and Y3Ga5O12:Ca,Ti are reported. The titanate host lattices are also doped with Eu3+. The data are discussed in terms of existing models. It is shown that a relation between quenching temperature and excitation maximum of the titanate emission holds and…
(Bi0.5Sb0.5)2Te3 single crystals doped with In atoms (cIn = 0 to 9.8 × 1020 cm−3) are prepared by the modified Bridgman method. From the analysis of the measurements of reflection spectra in the plasma resonance-frequency region, electrical conductivity, and the Seebeck coefficient it is found that an increase in the…
Several possibilities to design a cheap red lamp phosphor are reviewed. It appears to be possible to increase the amount of energy transfer from the niobate group in CaNb2O6 to Eu3+ on calcium sites by suitable substitutions. However, part of the niobate excitation energy still does not reach the Eu3+ ion. Only the me…
Numerical calculations of the density of tunneling and vibrational states of glasses within the soft-potential model (an extension of the tunneling model to include soft vibrations) are reported and compared to analytical approximations. Using a specific assumption on the asymmetry of the soft potentials, one is able…
A three-dimensional simulation of dislocation dynamics and interactions is applied to the question of the formation of cell structures in single crystals oriented for multiple slip. The numerical conditions selected are those of a [100]-oriented aluminium single crystal tested in constant total strain rate with a high…
For pt.II see ibid., vol.5, p.945 (1993). Measurements of the linear optical birefringence were used to determine the phase diagram of TbPO 4 at temperatures down to 1.4 K. At least one new structural and magnetic phase transition was found that is not detectable in magnetic investigations. Calculations using an appro…
Diaquabis(oxoacetato-O,O'')germanium(IV), [Ge(C 2 H 2 O 3 ) 2 (H 2 O) 2 ], was prepared from germanium dioxide and glycolic acid in refluxed H 2 Oand identified with IR, 1 H NMR, 13 C NMR, mass spectrum, elemental analysis, and X-ray single crystal structure determination. C 4 H 8 GeO 8 , M r =256.7, monoclinic, P2 1…