Macromolecular engineering of polyactones and polyactides. 12. Study of the depolymerization reactions of poly(.epsilon.-caprolactone) with functional aluminum alkoxide end groups
peer reviewed
Materials Literature
文献浏览
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。
X-ray double and triple crystal diffractometry of mosaic structure in heteroepitaxial layers
X-ray diffraction in thin layers containing small randomly placed defects is described by means of the kinematical diffraction theory and optical coherence formalism. The method enables us to calculate both the diffracted intensity and its angular distribution, so that it can be used for simulating double crystal and…
On the solid–fluid interface of adhesive spheres
The adhesive-sphere interaction potential provides a good model system to study the influence of the attractive well depth on phase behavior and interfacial phenomena. We investigate the solid–fluid phase behavior of adhesive spheres with the modified weighted density approximation (MWDA) of Denton and Ashcroft. We th…
Structure-function relationships for .beta., the first molecular hyperpolarizability
A four-orbital model is used to map the overall dependence of β, the first electronic hyperpolarizability, on \nchemical parameters such as donor/acceptor strength and coupling between bridge and donor/acceptor orbitals. These \ncalculations are used to develop general structure-property relationships for β an…
Heats of formation of silicon hydride oxide (SiHnO and SiHnO2) calculated by ab initio molecular orbital methods at the G-2 level of theory
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHeats of formation of silicon hydride oxide (SiHnO and SiHnO2) calculated by ab initio molecular orbital methods at the G-2 level of theoryCynthia L. Darling and H. Bernhard SchlegelCite this: J. Phys. Chem. 1993, 97, 31, 8207–8211Publication Date (Print):August 1, 1993Publi…
Optimal Distribution of Catalyst in Pellets
A large fraction of the chemical and refinery processes are catalytic in nature. While the worldwide sales of catalysts are only about $4 billion annually, the economic impact of catalysis comes from the fact that approximately $200 worth of products are manufactured for every $1 worth of catalyst consumed [1]. The ac…
Resolution and signal-to-background enhancement in gas-phase electron spectroscopy
The most important factors contributing to line broadening and background intensity in electron spectra are identified and new design principles for high quality measurements are presented. It is shown that time-dependent potential gradients in the gas cell are responsible for a large part of the ‘‘normal’’ line broad…
Effect of the spacer moiety on the rates of electron transfer within bis-porphyrin-stoppered rotaxanes
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEffect of the spacer moiety on the rates of electron transfer within bis-porphyrin-stoppered rotaxanesJean Claude Chambron, Anthony Harriman, Valerie Heitz, and Jean Pierre SauvageCite this: J. Am. Chem. Soc. 1993, 115, 16, 7419–7425Publication Date (Print):August 1, 1993Pub…
Correlation effects on Raman scattering from low-energy vibrational modes in glasses. II. Experimental results
New experimental results of low-frequency Raman scattering from different glasses are presented. They are compared to the vibration density of states obtained from inelastic neutron scattering to deduce the light-vibration coupling coefficient C(ω) as a function of the vibration frequency. It was found that C(ω)∝ω2 at…
Low-temperature magnetism in icosahedralAl70Mn9Pd21
We report measurements of the specific heat ${\mathit{C}}_{\mathit{p}}$(T), magnetic susceptibility \ensuremath{\chi}(T), and magnetization M(H) of icosahedral ${\mathrm{Al}}_{70}$${\mathrm{Mn}}_{9}$${\mathrm{Pd}}_{21}$ at low temperatures. Below room temperature, the static magnetic susceptibility is well described b…
Synthesis and properties of novel aromatic polyimides of 2,3-bis(4-aminophenoxy)naphthalene
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and properties of novel aromatic polyimides of 2,3-bis(4-aminophenoxy)naphthaleneChin Ping Yang and Wen Tung ChenCite this: Macromolecules 1993, 26, 18, 4865–4871Publication Date (Print):August 1, 1993Publication History Published online1 May 2002Published inissue…
TLSANL: TLS parameter-analysis program for segmented anisotropic refinement of macromolecular structures
The atomic displacements of many of the atoms in a macromolecular structure can be modelled in terms of group motions described in the harmonic approximation by T, L and S tensors. Relevant groups may be planar side groups of protein chains, units of secondary structure such as α-helices or whole protein domains. For…
Synthesis and characterization of novel epoxy monomers and liquid crystal thermosets
Abstract Four new epoxy monomers have been synthesized and characterized as part of a program to prepare novel liquid crystal thermoset (LCT) materials. Three of the new epoxy monomers contained a biphenyl mesogen and were not liquid crystalline (LC). The remaining epoxy monomer, which contained a 1,4‐dibenzoyloxybenz…
The Ericksen number and Deborah number cascades in sheared polymeric nematics
Samples of liquid crystalline poly(γ-benzyl-glutamate) solutions are sheared between glass surfaces with gaps, d = 10–500 μ, and shearing velocities, V = 0·05–10 000 μs−1 so that the Ericksen number E [tbnd] Vdγ 1/K is varied over a large range, E ≈ 1–107. Here γ1 is the rotational viscosity and K 1 is the Frank splay…
End-functionalized polymers. 1. Synthesis and characterization of perfluoroalkyl-terminated polymers via chlorosilane derivatives
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEnd-functionalized polymers. 1. Synthesis and characterization of perfluoroalkyl-terminated polymers via chlorosilane derivativesM. O. Hunt Jr., A. M. Belu, R. W. Linton, and J. M. DeSimoneCite this: Macromolecules 1993, 26, 18, 4854–4859Publication Date (Print):August 1, 19…
Formation of hydronium at the Broensted site in SAPO-34 catalysts
ADVERTISEMENT RETURN TO ISSUEArticleNEXTFormation of hydronium at the Broensted site in SAPO-34 catalystsLeonardo Marchese, Jiesheng Chen, Paul A. Wright, and John Meurig ThomasCite this: J. Phys. Chem. 1993, 97, 31, 8109–8112Publication Date (Print):August 1, 1993Publication History Published online1 May 2002Publishe…
Theoretical calculation of thermodynamic data for bcc binary alloys with the embedded-atom method
The dilute-limit heats of solution for all binary alloys of six bcc transition metals (V, Nb, Ta, Mo, W, and Fe) have been calculated with the analytic embedded-atom model for bcc pure metals by Johnson and Oh. Cubic equations are proposed and used for providing a smooth cutoff for the calculated potential and electro…
New antiferromagnetic dinuclear complexes of nickel(II) with two azides as bridging ligands. Magneto-structural correlations
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNew antiferromagnetic dinuclear complexes of nickel(II) with two azides as bridging ligands. Magneto-structural correlationsJoan Ribas, Montserrat Monfort, Carmen Diaz, Carles Bastos, and Xavier SolansCite this: Inorg. Chem. 1993, 32, 16, 3557–3561Publication Date (Print):Au…
Selective formation of an efficient Er-O luminescence center in GaAs by metalorganic chemical vapor deposition under an atmosphere containing oxygen
To investigate the effects of oxygen codoping on Er luminescence centers in GaAs, we grew Er-doped GaAs by low-pressure metalorganic chemical vapor deposition (MOCVD) and measured the photoluminescence spectrum due to the intra-4f-shell transition of Er. The spectrum of a sample grown in a pure hydrogen atmosphere was…
Two new .mu.-azido nickel(II) uniform chains: syntheses, structures, and magneto-structural correlations
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTwo new .mu.-azido nickel(II) uniform chains: syntheses, structures, and magneto-structural correlationsAlbert Escuer, Ramon Vicente, Joan Ribas, M. Salah El Fallah, Xavier Solans, and M. Font-BardiaCite this: Inorg. Chem. 1993, 32, 17, 3727–3732Publication Date (Print):Augu…