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。
Some aspects of local order in the amorphous state of a glassy polymer are discussed. The physical principles behind a cluster model involving the new concept of a structural defect are presented. A comparative analysis of three major approaches to describing the amorphous state of a polymer is given. It is shown that…
When body-centered-cubic crystals undergo plastic deformation, the slip planes are often noncrystallographic. By performing atomistic simulation on the activation pathway of dislocation jumps in bcc iron, we show that the main reason for bcc crystals to exhibit this phenomenon is that one type of kink pair has signifi…
The data of IR, 1H NMR and electronic absorption spectroscopy of porphyrins and their precursors and derivatives are analysed, systematised and generalised. The bibliography includes 105 references.
Poly(ethylene glycol) (PEG) ( M w = 6k, 10k, and 20k g/mol) terminated at both ends by hydrophobic fluoroalkyl segments (−(CH 2 ) 2 C n F 2 n +1, n = 6, 8, or 10) was synthesized and demonstrated to self-assemble into hydrogels with phase behavior and mechanical and erosion properties that can be systematically varied…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTSurface Mobile Layer of Polystyrene Film below Bulk Glass Transition TemperatureDaisuke Kawaguchi, Keiji Tanaka, Atsushi Takahara, and Tisato KajiyamaView Author Information Department of Applied Chemistry, Faculty of Engineering, K…
Electroactive and blue light-emitting poly(vinyl diphenylquinoline) (PVQ) was synthesized in nearly quantitative yield by a simple modification of polystyrene. The new polymer and its model compound 2,4-diphenylquinoline were characterized by 1 H NMR, FT-IR, photoluminescence spectroscopies, and thermal analysis. PVQ…
Abstract The state of sorbed water and the sorbing processes of water to various polymer thin films were studied with Fourier transform infrared (FTIR) spectroscopy. To prepare the polymer films, we used poly(ethylene glycol)s of different molecular weights and various kinds of vinyl polymers, such as poly(2‐methoxyet…
The free energy of antiferroelectric smectic liquid crystals which takes into account polar order explicitly is presented. Steric, van der Waals, piezoelectric, and flexoelectric interactions to the nearest layers, and dipolar electrostatic interactions to the nearest and to the next-nearest layers, induce indirect ti…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTEnforced Stacking in Crowded ArenesMark L. Bushey, Austin Hwang, Peter W. Stephens, and Colin NuckollsView Author Information Department of Chemistry, Columbia University New York, New York 10027 Department of Physics and Astronomy State University of New York at Stony…
The photophysical properties of a perylene−porphyrin dyad have been examined with the aim of using this construct for molecular photonics applications. The dyad consists of a perylene-bis(imide) dye (PDI) connected to a zinc porphyrin (Zn) via a diphenylethyne linker (pep). In both polar and nonpolar solvents, the pho…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTBifunctional Molecular Sieve Catalysts for the Benign Ammoximation of Cyclohexanone: One-Step, Solvent-Free Production of Oxime and ε-Caprolactam with a Mixture of Air and AmmoniaRobert Raja, Gopinathan Sankar, and John Meurig ThomasView Author Information Davy Faraday…
The structural changes of polycrystalline $R{\mathrm{NiO}}_{3}$ perovskites $(R=\mathrm{Ho},$ Y, Er, and Lu, prepared under high-oxygen pressure) across the metal-insulator (MI) transition ${(T}_{\mathrm{MI}}$ ranging between 573 and 600 K) have been studied by high-resolution neutron- and synchrotron diffraction tech…
The use of steady-state and time-resolved fluorescence spectroscopy to probe the internal microenvironment of sol−gel-derived organic−inorganic nanocomposites formed from alkoxysilane precursors is reviewed. The review focuses on the use of small organic probes and fluorescent biomolecules that provide information on…
Exothermic reactions between a porous matrix and an infiltrating melt provide a more economic alternative for synthesizing many ceramics, intermetallics, and composites. It has recently been demonstrated that infiltration of cast microporous carbon preforms by silicon melt can be used to fabricate high-density, nearly…
A series of complexes ML2(x+) (M = Mn-Zn, L = 2,6-bis(iminomethyl)pyridine) was investigated by theoretical methods. Electron transfer from the metal "t(2g)" orbitals to the ligand pi orbitals is reflected in the elongation of ligand C-N bonds and shortening of the C(py)-C(imine) bonds. Using zinc complexes as referen…
Sound propagation in a Fermi liquid with impurities is studied using the Landau-Boltzmann equation and the result is compared with a recent experiment in liquid ${}^3$He in aerogel by Northwestern University group. The sound absorption calculated using the fixed impurity model is a few orders of magnitude larger than…
First, we present a two-dimensional lattice gas model with anisotropic interactions which explains the experimentally observed transition from a dominant c(2x2) ordering of the CdTe(001) surface to a local (2x1) arrangement of the Cd atoms as an equilibrium phase transition. Its analysis by means of transfer-matrix an…
We report on the MBE-growth and magnetotransport properties of p-type BeMnTe, a new ferromagnetic diluted magnetic semiconductor. BeMnTe thin film structures can be grown almost lattice matched to GaAs for Mn concentrations up to 10% using solid source MBE. A high p-type doping with nitrogen can be achieved by using a…
The epitaxial growth process of a high symmetry surface occurs because adatoms meet and nucleate new islands, that eventually coalesce and complete atomic layers. During multilayer growth, nucleation usually takes place on top of terraces where the geometry of the diffusion process is well defined: We have studied in…
A novel ligand, 2,2‘-methylenebis(4,6-di(1-methyl-1-phenylethyl)phenol) (MMPEP-H 2 ) ( 1 ), has been prepared by the reaction of 2,4-bis(α,α-dimethylbenzyl)phenol with formaldehyde in the presence of a catalytic amount of benzenesulfonic acid. Further reaction of compound 1 with Me 3 Al in diethyl ether produces a fou…