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。
Abstract Differential scanning calorimetry (DSC) was used to analyze the crystal distribution in homogeneous ethylene–octene copolymers polymerized by the constrained geometry catalyst technology (CGCT). To minimize ambiguities from thermal history effects, copolymers were isothermally annealed at temperatures within…
Equations of motion for model colloidal particles are derived, which include a mean-field local density representation for the many-body-hydrodynamics (MBH) interactions. These are implemented as a modification of Ermak's 1975 Brownian dynamics free-draining algorithm, with a local density prescription for the frictio…
The magnetic properties and microstructures of rapidly quenched Sm–Fe–N powders with low Sm contents and Zr and Co addition have been studied. High remanence values of 9.4 kG with high HcJ values of 7–10 kOe were obtained for isotropic powders. The x-ray diffraction analysis and transmission electron microscopy (TEM)…
We present experimental studies of the growth of 3D xenon dendrites into a supercooled pure melt. The shape of the dendrite tip and the origin of the sidebranching is investigated. The shape in the tip region is not axisymmetric and four fins grow along the dendrite. Sidebranches develop at the ridges of these fins. T…
A mixture of methane, hydrogen, and oxygen has been used to etch thin films of NiFe. The variation of etch rate with concentration of methane and oxygen has been investigated. By using a SrF2 mask, patterned by liftoff, small micrometer-sized elements have been fabricated. It is demonstrated that the use of CH4/H2/O2…
The dark conductivity and transient photoconductivity measurements on thin films of a-Se 80-x Te x Ga 20 (0<or=x<or=20) have been reported in the temperature range from 148 to 318 K. The results indicate that, at higher temperatures, hopping conduction takes place in the tail states. At lower temperatures the conducti…
Polycrystalline pyrolytic graphite was compressed in a diamond anvil cell to pressures up to 73 GPa. In situ Raman measurements reveal evidence of a phase transition at 15-20 GPa, consistent with earlier static high-pressure experiments on graphite. The sample was quenched by rapid downloading of the cell to ambient p…
(RP)-cAMPS is known to inhibit competitively the cAMP-induced activation of cAMP-dependent protein kinase (PKA). The molecular nature of this inhibition, however, is unknown. By monitoring the intrinsic tryptophan fluorescence of recombinant type I regulatory subunit of PKA under unfolding conditions, a free energy va…
Unhydrogenated diamondlike carbon (DLC) thin films have been deposited by laser ablation of graphite, using a high power Ti: sapphire solid state laser system. DLC films were deposited onto silicon substrates at room temperature with subpicosecond laser pulses, at peak intensities in the 4×1014–5×1015 W/cm2 range. A v…
The grain boundary regions of nanophase Cu metal are investigated using the x-ray absorption fine structure (XAFS) technique. Typical samples made by standard techniques need to be greatly thinned if measured in transmission in order to eliminate experimental artifacts which erroneously lower the apparent coordination…
Crystallization is used industrially for the recovery and purification of many inorganic and organic materials. However, very little is reported on the application of bulk crystallization for proteins. In this work, ovalbumin was selected as a model protein to investigate the feasibility of using bulk crystallization…
By using angle-resolved electron spectroscopic methods, we have investigated a monolayer film of hexagonal boron nitride ($h$-BN) epitaxially formed on Ni(111), Pd(111), and Pt(111). The electronic structure of the monolayer $h$-BN is almost independent of the substrate, which is in striking contrast with the case of…
Mixed-valence manganites $({{A}^{3+}}_{0.7}{{B}^{2+}}_{0.3})\mathrm{Mn}{\mathrm{O}}_{3}$ exhibit a resistivity peak with giant negative magnetoresistance below the Curie point. Residual resistivity ranges from 5\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}8}$ to 8\ifmmode\times\else\texttimes\fi{}${10}^{3}$…
Der Hydroxysubstituent machts möglich! Im Gegensatz zum nichtaromatischen Benziporphyrin 1a (X H) ist beim Hydroxyderivat 1b (X OH) das durchkonjugierte, vollständig aromatische Semichinon‐Tautomer 2 begünstigt. magnified image
Formaler Austausch der Pyrrolkerne in Porphyrin durch Bipyrrol‐Einheiten führt zu der Titelverbindung 1 . Das Hexadecaethyl‐Derivat von 1 ist einziges isolierbares Produkt der MacDonald‐Kondensation sowohl geeigneter tetrapyrrolischer als auch dipyrrolischer Komponenten. Das neue Cyclooctapyrrol liegt im Kristall und…
Die Cyclooctapyrrole 1‐3 sind eindrucksvolle Beispiele dafür , daß bei der Kondensation von dipyrrolischen Bausteinen die Bildung von Cyclooctapyrrolen gegenüber der entsprechender Cyclotetrapyrrole bevorzugt sein kann, wenn die Cyclisierung zu letzteren konformativ behindert ist. Die Makrocyclen sind chiral und könnt…
The real-space structure of hard-sphere glasses quenched from colloidal liquids in thermodynamic equilibrium has been determined. Particle coordinates were obtained by combining the optical sectioning capability of confocal fluorescence microscopy with the structure of specially prepared fluorescent silica colloids. B…
Abstract A key reaction in the biological and material world is the controlled linking of simple (molecular) building blocks, a reaction with which one can create mesoscopic structures, which, for example, contain cavities and display specifically desired properties, but also compounds that exhibit typical solid‐state…
A high-intensity electron gun based on field emission from a film of aligned carbon nanotubes has been made. The gun consists of a nanotube film with a 1-millimeter-diameter grid about 20 micrometers above it. Field-emission current densities of about 0.1 milliampere per square centimeter were observed for applied vol…
X-ray diffraction (XRD) has been used for the study of bi-intercalation of ICl into the stage-5 ${\mathrm{FeCl}}_{3}$ graphite intercalation compound (GIC). The stage-5 ${\mathrm{FeCl}}_{3}$ GIC is obtained when the temperature of graphite is set at 788 K, and the temperature of ${\mathrm{FeCl}}_{3}$ at 573 K in the t…