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 have investigated the dielectric properties of Ti-doped K(Ta,Nb)O 3 films subjected to high temperature annealing. Titanium (+4) substitution on the Nb/Ta site introduces an acceptor state, thus reducing dielectric losses due to defect-related donor states. Using 3% Ti-doped targets, K(Ta,Nb)O 3 : Ti films were gro…
The off-stoichiometric Heusler alloy Co 50 Ni 20 Ga 30 was synthesized by using the melt-spinning technique. The Co 50 Ni 20 Ga 30 ribbon exhibited a thermo-elastic martensitic transformation from cubic to a tetragonal structure at 270 K during cooling. The martensitic phase at lower temperature exhibited a high-satur…
Abstract Single-crystalline gold nanorods have been prepared by one-step, seedless solvothermal reduction of HAuCl4·4H2O in cetyltrimethylammonium bromide (CTAB)/octane + butanol/formamide microemulsions. Formamide provides not only reduction but also sites occupied by Au3+ ion through replacing “water pools” in the t…
Nanostructured diamond was grown by microwave plasma chemical vapour deposition onto 2 mm diameter quartz spheres using a H2/CH4/N2 feedgas mixture high in methane concentration (15% by volume). Deposition experiments were performed at low temperature (<425°C, below the temperature limit of the optical pyrometer used)…
Abstract Fluid penetration through porous networks consists of two different phenomena: (1) pore fluid displacement and (2) fluid flow through the pores. The first phenomenon depends on the pore size, the fluid–fluid interfacial tension, and the contact angle. The second phenomenon is pore‐size‐ and viscosity‐dependen…
Abstract The intermolecular structural heterogeneity of a propylene‐ethylene random copolymer was studied by preparative temperature rising elution fractionation combined with GPC, 13 C‐NMR, differential scanning calorimetry, and wide‐angle X‐ray diffraction analysis of the obtained fractions. The isotacticity of frac…
The structure of cytochrome c-550 from the nonphotosynthetic bacteria Paraccocus versutus has been solved by X-ray crystallography to 1.90 A resolution, and reveals a high structural homology to other bacterial cytochromes c(2). The effect of replacing the axial heme-iron methionine ligand with a lysine residue on pro…
A self-consistent-field theory for fluids of homogeneous wormlike polymers exhibiting a one-dimensional spatial variation is presented. We have extended the treatment of excluded-volume effects by adding an effective interaction term which describes the excluded volume between wormlike cylindrical segments and termina…
Abstract Summary: We follow the time development of the microdomain structure in symmetric polystyrene‐ block ‐poly(methyl methacrylate) (PS‐ b ‐PMMA) diblock copolymer thin films during acetone vapor treatment. Besides the highly ordered nanoscopic spheres or stripes as reported previously, a novel so‐called flower‐l…
Germanium nanocrystals were synthesized in supercritical (sc) CO(2) by thermolysis of diphenylgermane (DPG) or tetraethylgermane (TEG) with octanol as a capping ligand at 500 °C and 27.6 MPa. The Ge nanocrystals were characterized with high resolution transmission electron microscopy (HRTEM), energy-dispersive x-ray s…
In absence of chaperone DnaK, bacterially produced misfolding-prone proteins aggregate into large inclusion bodies, but still a significant part of these polypeptides remains in the soluble cell fraction. The functional analysis of the model beta-galactosidase fusion protein VP1LAC produced in DnaK(-) cells has reveal…
Photodetached $d$-electron angular distributions have been measured for the processes ${\mathrm{V}}^{\ensuremath{-}}{(3{d}^{4}4{s}^{2})}^{5}D+h\ensuremath{\nu}\ensuremath{\rightarrow}\mathrm{V}{(3{d}^{3}4{s}^{2})}^{4}F+{e}^{\ensuremath{-}}$, ${\mathrm{V}}^{\ensuremath{-}}{(3{d}^{4}4{s}^{2})}^{5}D+h\ensuremath{\nu}\ens…
Structural and electronic properties of single zinc etioporphyrin molecules adsorbed on Al2O3/NiAl(110) were probed by a low-temperature scanning tunneling microscope (STM). Scanning tunneling spectroscopy (STS) revealed progressions of spectral features corresponding to the vibronic states of individual molecules tha…
We have studied the stability of RCo 5− x Cu x (R = Y, Sm) compounds with respect to phase separation. First principles density functional calculations imply that (i) decomposition into two phases having different x is energetically favourable and (ii) both the stable x values and the Cu atomic site preferences depend…
Molecular dynamics and resulting disorder in the soft crystal, smectic E (SmE) phase, were studied in detail for the title compound, 4-butyl-4'-isothiocyano-1,1'-biphenyl (4TCB), by (1)H NMR spectroscopy and adiabatic calorimetry. The ordered crystal phase of 4TCB was realized for the first time under ambient pressure…
Abstract Summary: The annealing and melting behavior of poly[( R )‐3‐hydroxybutyrate] (P(3HB)) single crystals were followed in real time by synchrotron small‐ (SAXS) and wide‐angle X‐ray scattering (WAXS) measurements. The real‐time SAXS measurements revealed that the P(3HB) single crystal exhibits a discontinuous in…
Current versus voltage (I versus V) and complex impedance, z*(f) = z'(f) − iz''(f), measurements for polyaniline (PANI) films were carried out in samples with different doping levels and gold and/or aluminium as electrodes. The complex impedance of Au/PANI/Au presents the typical behaviour of a somewhat solid disorder…
The double-doped ${\mathrm{Pr}}_{0.5+0.5x}{\mathrm{Ca}}_{0.5\ensuremath{-}0.5x}{\mathrm{Mn}}_{1\ensuremath{-}x}{\mathrm{Cr}}_{x}{\mathrm{O}}_{3}$ system $(0.01\ensuremath{\leqslant}x\ensuremath{\leqslant}0.10)$ has been investigated. A training effect by the application of magnetic field is observed. The magnetic hyst…
The structural, dielectric and piezoelectric properties of xPMS–(1 − x)PZT ceramics were investigated as a function of Pb(Mn1/3Sb2/3)O3 (PMS) content by x-ray diffraction, scanning electron microscopy, and dielectric and piezoelectric spectroscopy techniques. All the Pb(Mn1/3Sb2/3)O3–PbZrO3–PbTiO3 (PMS–PZT) samples ex…
The low thermal stability of nanoparticles typically restricts their use in catalytic and other applications to low- to moderate-temperature conditions. We present a novel approach to the stabilization of nanosized noble metal particles by embedding them in a high-temperature stabilized hexa-aluminate matrix. The simp…