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 magnetic properties of the ball-milled nanocrystalline fcc phase of FeRh alloys are reported and discussed. The observed features (maximum of ac and zero-field cooling susceptibility at a temperature ${T}_{\mathrm{max}}$ weakly dependent on the frequency and on the applied field) suggest a progressive blocking of…
In this paper, the feasibility of automatic least-squares refinement of a Monte Carlo model of a disordered structure by quantitative comparison of its calculated diffraction pattern with observed diffuse scattering data is demonstrated. At each stage of the refinement, the goodness-of fit parameter χ2 is used as a qu…
Abstract Secondary electron imaging is not possible in the variable pressure scanning electron microscope because the mean free path of the secondaries in the gas is too short to permit them to reach the detector. This paper therefore investigates an alternative strategy for producing an image containing significant a…
Wetting and reactions between molten Al and silicate substrates (particularly mullite) are studied to determine both how substrate tensity and p (O 2 ) influence wetting behavior, reaction rates, composition, and reaction product microstructure and what key steps control penetration kinetics. Guidelines are provided f…
The crystal structure of a Zn-Mg-Y hexagonal phase, considered to be related to that of the quasicrystalline phase, has been determined by single-crystal X-ray diffraction. The atomic model, refined to a final R value of 0.027, has the composition Zn65.22Mg27.92Y6.86 and 92 atoms in a unit cell with lattice constants…
By spatially resolved single-wavelength ellipsometry, we investigate the spreading on a solid substrate of low molecular weight trimethyl-terminated poly(dimethylsiloxane) droplets. Especially, we focus our study on the dependence of the diffusion coefficient of the first molecular layer on the substrate surface energ…
Re(O)Cl(3)(PPh(3))(2), 1, and Re(O)Cl(3)(OPPh(3))(Me(2)S), 2, catalyze the oxidation of thiols to disulfides with sulfoxides under mild conditions. Catalyst 1 exhibits an induction period which features PPh(3) oxidation to OPPh(3) prior to disulfide formation. This lag is absent when 2 is the catalyst precursor. Other…
Phase boundary and domain structure in relaxor ferroelectrics Pb(Zn 1/3 Nb 2/3 )O 3 /9%PbTiO 3 were observed using a (111) plate under a polarization microscope. The dielectric constant was measured simultaneously to determine exact transition temperatures and to connect the dielectric behavior with phase boundary mov…
Chiral polyaniline colloids have been generated via the electrohydrodynamic polymerization of aniline in aqueous (+)- or (−)-10-camphorsulfonic acid (HCSA) using polystyrene sulfonate (PSS) as a steric stabilizer and codopant. Potentiostatic polymerization at +0.9 V (vs Ag/AgCl) was employed. The colloidal PAn·HCSA/PS…
Bismuth sodium titanate, (Bi 1/2 Na 1/2 )TiO 3 (BNT)-based solid solution, a (Bi 1/2 Na 1/2 )TiO 3 – b KNbO 3 – c 1/2(Bi 2 O 3 ·Sc 2 O 3 ) ( a + b + c =1), [KTNS(100 a /100 b /100 c )], was studied for its dielectric, ferroelectric and piezoelectric properties, as a new group of lead-free piezoelectric ceramics. Elect…
We report neutron scattering experiments on several Al-Pd-Mn liquid alloys with Mn content between 3.5 and 7.2 at. % which are in thermodynamical equilibrium with icosahedral quasicrystalline or approximant phases. The results reveal an overall similarity between the structure factor in the solid and in the liquid sta…
We investigate the local structural heterogeneities that may appear in liquid water by studying a model of interacting water pentamers. We find local energy minima which we identify with well-defined configurations, and advance the hypothesis that one of these configurations may be related to local “high-density” stru…
The photoabsorption and photoluminescence properties of two-coordinated Si, Ge, and Sn defect centers and the magnetic interactions of the corresponding $[=\mathrm{S}\mathrm{i}\ensuremath{-}\mathrm{H}{]}^{\ifmmode\bullet\else\textbullet\fi{}},$ $[=\mathrm{G}\mathrm{e}\ensuremath{-}\mathrm{H}{]}^{\ifmmode\bullet\else\t…
In this work the lyotropic liquid crystal nematic state of poly( n -hexyl isocyanate) (PHIC) was converted to the cholesteric state by doping with a variety of chiral small molecules and with optically active polyisocyanates. Circular dichroism experiments in dilute isotropic PHIC solutions show that several of the sm…
Phase transition in [N(C2H5)4]2ZnCl4 has been investigated by means of X-ray diffraction and high-resolution 13C-NMR. Structure determination shows that [N(C2H5)4]+ ion involves disordering between two Nordic crosses at room temperature. 13C-NMR spectra considerably broaden near the transition point in the high temper…
In order to develop a corrosion-free halogen gas delivery system for use in semiconductor manufacturing, Cr2O3 passivation of ferritic and austenitic stainless steels has been investigated. It has been shown that a Cr2O3 layer can be formed on an electropolished (EP) surface of ferritic 26Cr–1Mo stainless steel by oxi…
Abstract Using an adiabatic calorimeter direct measurements of the heat capacity of the liquid Si 15 Te 85 , Ge 15 Te 85 , Sn 15 Te 85 , Pb 11 Te 89 , Pb 11 Te 89 and Bi 10 Te 90 alloys and of liquid tellurium have been performed. The heat capacity has been measured as a function of temperature up to about 100 K above…
Using a previously developed theory of nematic liquid crystals (Singh, Y., and Singh, K., 1986, Phys. Rev. A, 33, 3481) we present the calculation of elastic constants of discoticnematic liquid crystals and study the variation of elastic constants with packing fraction. The expressions for elastic moduli associated wi…
Abstract Lichtquellen hoher Leuchtdichte sind Schlüsselkomponenten für das Projektionsfernsehen. Mit der Entwicklung der UHP‐Lampe (Ultra‐High‐Performance) von Philips wurde hier ein entscheidender Durchbruch erzielt. Durch die erstmalige Realisierung einer Quecksilber‐Höchstdruckentladung mit einem Halogen‐Kreisproze…
Carbon nanostructures were prepared by catalytic decomposition of benzene on Co/SiO2 catalysts at 873 K. As a function of particle size and reactive mixture, carbon filaments and nanotubes were obtained and various shapes observed such as straight, curved and helically-coiled nanotubes. Particularly, it was shown that…