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。
An investigation was carried out on the dipole dynamics of low molecular weight crown ether series and related compounds by dielectric relaxation spectroscopy (DRS). An unexpected discovery regarding two main relaxations observed by DRS and calorimetric (DSC) measurements have been analyzed using neat and solvent-pres…
The surface microhardness of conventional thermoplastics lie between 0.1 and 0.6 GPa. The as-cast emeraldine (EM-25) base film of polyaniline (PANi) exhibits a surface microhardness of about 1 GPa. The hardness is increased to about 4 GPa in the highly cross-linked EM (EM-150) film. This hardness value is further enha…
To clarify the N 2 formation mechanism during the C−N 2 O reaction, the detailed nitrogen mass balance was established. It was also attempted to reveal the role of surface nitrogen species in this reaction by using isotope gases. In contrast to the case of the C−NO reaction, the accumulation of nitrogen on the carbon…
In situ small-angle X-ray scattering (SAXS) rheology is used to study the dynamic process of shear alignment in a lamellar poly(styrene- b -ethylene propylene) diblock copolymer, at temperatures far below the microphase separation transition temperature. We have focused on the alignment dynamics at time scales shorter…
Two new classes of octupolar nonlinear chromophores, deriving from 1,3,5-triazines and oligothienylic crystal violet analogues, have been synthesized and their nonlinear properties investigated using the harmonic light scattering experiment. The easy preparation of these molecules makes them attractive candidates for…
We apply the Merrifield variational method to the Holstein molecular crystal model in D dimensions to compute non-adiabatic polaron band energies and Franck-Condon factors at general crystal momenta. We analyze these observable properties to extract characteristic features related to polaron self-trapping and potentia…
We report observation of strongly enhanced surface SHG in BaTiO_3 due to excitation of a photorefractive surface electromagnetic wave. Surface SH intensity may reach 10^{-2} of the incident fundamental light intensity. Angular, crystal orientation and polarization dependencies of this SHG are presented. Possible appli…
In this paper there is presented method for ab initio calculation of the phonon spectra. The method is based upon a direct calculation of the dynamical matrix via second derivatives of the total energy. The pseudopotential technique in plane-wave basis set was used to calculate the total energy within the local densit…
ADVERTISEMENT RETURN TO ISSUEArticleNEXTInteraction of Sulfur with Well-Defined Metal and Oxide Surfaces: Unraveling the Mysteries behind Catalyst Poisoning and DesulfurizationJosé A. Rodriguez and Jan HrbekView Author Information Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 Cite this: A…
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” opt…
Three series of poly(pyromellitimide-ester)s were synthesized from various N,N′-bis(ω-hydroxyalkyl)pyromellitimides (HAPMIs) by melt condensation with dicarboxylic acids, including terephthalic acid (TPA), 4,4′-biphenyldicarboxylic acid (BPDA), and 4,4′-azobenzenedicarboxylic acid (ABDA). Polymers were characterized b…
Polynuclear transition-metal complexes, such as Fe–S clusters, are the prosthetic groups in a large number of metalloproteins and serve as temporary electron storage units in a number of important redox-based biological processes. Polynuclearity distinguishes clusters from mononuclear centers and confers upon them uni…
Surface-phonon-dispersion curves of the (001) surfaces of the GaSe and InSe films epitaxially grown on the hydrogen-terminated $\mathrm{Si}(111)(1\ifmmode\times\else\texttimes\fi{}1)$ surface have been investigated by high-resolution inelastic helium-atom scattering. The phonon-dispersion curves of the GaSe(001) thin…
The chemistry of methyl bromide on Cu/Ru(001) has been studied utilizing work function change (Δφ) and temperature-programmed desorption (TPD) measurements. The remarkable modification in the methyl fragments dehydrogenation at the completion of a single copper layer and the significant difference in reactivity of the…
We have performed x-ray-absorption spectroscopy (XAS) and x-ray-photoemission spectroscopy (XPS) studies of single crystal ${\mathrm{Ba}}_{1\ensuremath{-}x}{\mathrm{K}}_{x}{\mathrm{BiO}}_{3}$ (BKBO) covering the whole composition range $0<~x<~0.60.$ Several features in the oxygen $1s$ core XAS spectra show syste…
We have prepared noncollapsed free-standing porous silicon (PS) films with various porosities even higher than 90% using the electrochemical etching−electropolishing, chemical dissolving, and supercritical drying methods. The result of a study combining optical absorption and photoluminescence (PL) from free-standing…
Highly porous poly(L-lactic acid)/apatite composites were prepared through in situ formation of carbonated apatite onto poly(L-lactic acid) foams in a simulated body fluid.The highly porous polymer foams (up to 95% porosity) were prepared from polymer solution by solidliquid phase separation and subsequent sublimation…
Large–strain plastic deformation at low homologous temperature implies, among other things, severe work hardening, strong crystallographic texturing, microstructural refining, and some degree of macroscopic redundant strain. In most cases, the development of texture does not seem to particularly increase grain interac…
The occurrence of a molecular complex between poly(ethylene oxide) (PEO) and p-dihydroxybenzene (hydroquinone) has been determined using different experimental techniques such as differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and Fourier transform infrared spectroscopy (FTIR). From DSC i…
This research discussed the effect of the addition of antimony catalyst on diethylene glycol (DEG) formation in poly(ethylene terephthalate) (PET) synthesis. It was found that antimony catalyst increased DEG formation in the preparation of PET, in particular, during the esterification stage and also during the prepoly…