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。
Porous CdS and SnS films with ordered nanohole array structures were produced from anodic porous alumina by a two-step replication process. The nanohole array structure was formed by electrodeposition of CdS or SnS onto a prepared negative structure of the porous alumina template. The porous metal sulfide films with u…
Magnetization and electrical resistivity measurements have been made on ${\mathrm{Fe}}_{2\ensuremath{-}x}{\mathrm{Ni}}_{x}\mathrm{TiSn}$ and ${\mathrm{Fe}}_{2\ensuremath{-}x}{\mathrm{Co}}_{x}\mathrm{TiSn}$ cubic solid solutions. The electrical resistivity reveals a strong influence of spin fluctuations for ${\mathrm{F…
The mode of microscopic deformation in rubber-modified amorphous polymers has been investigated by small-angle X-ray scattering during tensile deformation. Synchrotron experiments were performed for blends consisting of poly(methyl methacrylate) (PMMA) with a finely dispersed rubbery epoxy phase. These blends were pre…
The structures of sodium (+)-tartrato arsenate(III),[Na8As10(C4H2O6)8(C4H3O6)2(H2O)19]n(1), silver (+)-tartrato arsenate(III),[Ag9As10(C4H2O6)9(C4H3O6)(H4As2O5)(H2O)10](2) and rubidium citrato antimonate(III)[Rb2Sb4(C6H6O7)6(C6H7O7)2(H2O)2](3) have been determined by X-ray methods and refined to residuals of 0.085(1),…
The structural, thermal, and nonlinear optic (NLO) characterization of different polar materials is reported. These materials, which range from side-chain polymers to anisotropic networks and gels, were prepared by in situ photopolymerization of their precursors in the ferroelectric SmC* liquid crystal phase. The infl…
Computer modeling techniques provide a useful mechanism with which to model the morphology of defect crystals. In this work, a study of the incorporation of sodium and potassium cations into the morphologically important surfaces of gibbsite was conducted. Computation of the resulting changes in surfaces energies was…
The speciation and equilibria of sodium metatungstate, Na6[H2W12O40], has been determined by a combination of 183W n.m.r. spectroscopy and gravimetry over the p[H] range 4.5–10.0. The use of n.m.r. spectroscopy allowed the direct observation of polytungstate anions in aqueous solution and high concentration (0.25 mol…
We report the temperature-dependent infrared spectra of pure, deuterated, Zn-doped, and 2,6-dimethyl-substituted samples of the S = 1 / 2, one-dimensional Quantum Heisenberg Antiferromagnet (QHAF) copper pyrazine dinitrate (Cu(C 4 H 4 N 2 )(NO 3 ) 2 ). Of the more than 100 vibrational modes observed in the spectra, ne…
Poly(epsilon-caprolactone), PCL, is a commercial biodegradable and biocompatible polyester that can be bioassimilated by outdoor microorganisms. For biomedical and environmental applications, monitoring the fate of degradation products in vivo or under environmental conditions is one of the critical steps to evaluate…
Compositional variation of magnetoresistance (MR) ratio with silver excess stoichiometry in ${\mathrm{Ag}}_{2+\ensuremath{\delta}}\mathrm{Se}$ samples has been studied employing a synthetic approach to prepare instantly a series of bulk silver selenide compounds using microwave energy. Bulk density >99% is achieved…
We have previously reported the use of titanium alkoxide complexes as initiators for the living polymerization of isocyanates. In this paper, we present the synthesis of a trimetallic initiator, 2, comprised of three titanium alkoxides connected to a central organic core and the use of this catalyst to form three-arm…
Toughness enhancement of brittle amorphous polymers can be obtained via microstructural adjustments, resulting effectively in a removal of intrinsic strain softening on the mesoscale via a decrease in yield stress and an increase in strain hardening. Generally the introduction of a dispersed soft phase is required wit…
Oligomeric peptides can be designed which undergo one-dimensional self-assembly in solution to form beta-sheet tapes a single molecule in thickness and micrometers in length.(1) In this paper, we present the first systematic investigation of the size, shape, dynamics, and interactions of beta-sheet tapes formed by a s…
In this paper, we report differential scanning calorimetry studies of the temperature and molar mass dependences for the primary and secondary crystallization behavior of bisphenol A polycarbonate (BAPC). The molar mass dependence of the crystallization rate is found to be much stronger during primary than during seco…
We have investigated electrochemical switching of excited-state electronic energy migration in two optoelectronic gates with different architectures. Each gate consists of diarylethyne-linked subunits: a boron-dipyrrin (BDPY) input unit, a Zn-porphyrin transmission unit, a free-base-porphyrin (Fb-porphyrin) output uni…
Extremely large carbon tubes, some exceeding 5 microm in diameter, were produced with both laser and electric arc techniques using graphite, a transition metal catalyst, and a reactive third-body gas. We have named these structures carbon megatubes. They are the first carbonaceous tubes large enough to observe using o…
Direct self-polycondensation of an AB 2 type monomer ( 1 ) followed by chemical modification with a branched reagent ( 2 ) afforded a precursor. Chemical imidization of the precursor gave a hyperbranched aromatic polyimide ( 12 ) with a weight-average molecular weight of 98 000 and an inherent viscosity of 0.13 dL/g.…
The complex [Fe[HC(3,5-Me(2)pz)(3)](2)](BF(4))(2) (pz = pyrazolyl ring) undergoes a phase transition that occurs concomitantly with a thermally induced spin conversion between the high-spin (HS, S = 2) and low-spin (LS, S = 0) states. Above 204 K the compound is completely HS with the structure in the C2/c space group…
Colloidal gold particles synthesized in water have been capped with octadecanethiol (ODT) molecules rendered water-soluble by threading with α-cyclodextrin (α-CD) molecules. Thereafter, the gold nanoparticles could be transferred into an organic solvent such as chloroform by vigorous shaking of a biphasic mixture of t…
As postulated by Fowler and Ugalde [ J. Phys. Chem. A 2000, 104, 397], the lowest-energy B 13 + isomer proved to be highly aromatic. The topological resonance energy of this cationic boron cluster is positive in sign and very large in magnitude. This constitutes the definitive reason B 13 + is kinetically stable and p…