Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOff-lattice Monte Carlo simulations of polymer melts confined between two plates. 2. Effects of chain length and plate separationSanat K. Kumar, Michele Vacatello, and Do Y. YoonCite this: Macromolecules 1990, 23, 8, 2189–2197Publication Date (Print):April 1, 1990Publication…
Near‐phase pure perovskite lead magnesium niobate (PMN) with MgO or PbO additives was produced by reacting PbO with MgNb 2 O 6 at 800°C and sintering at 1200°C. Dense ceramics were characterized by scanning electron microscopy, X‐ray diffraction, and dielectric measurements. The microstructural studies showed that exc…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and optical properties of conformationally constrained trimeric and pentameric porphyrin arraysToshi Nagata, Atsuhiro Osuka, and Kazuhiro MaruyamaCite this: J. Am. Chem. Soc. 1990, 112, 8, 3054–3059Publication Date (Print):April 1, 1990Publication History Published…
A current-estimation approach to support the analysis of electromigration (EM) failures in power supply and ground buses of CMOS VLSI circuits is discussed. It uses the original concept of probabilistic simulation to efficiently generate accurate estimates of the expected current waveform required for electromigration…
Abstract The thermal behavior of poly(etheretherketone)(PEEK) film heated in an open differential scanning calorimetry (DSC) pan at 20°C/min is distorted by relaxation of the strained film. PEEK film in a closed pan or quenched PEEK in open or closed pans shows a glass‐transition temperature ( T g ) around 144°C, cold…
Analyse statistique de l'energie et des modes d'empilement des cristaux d'hydrocarbures. Discussion des effets de la taille moleculaire, de la forme et de la stœchiometrie sur l'energie d'empilement. Estimation des effets du rapport carbone/hydrogene sur l'empilement. Evaluation du nombre de coordination moleculaire
The complex resonance eigenvalue can easily be obtained by scaling the internal coordinates of the Hamiltonian by a complex factor since then the resonance eigenfunction ${\mathrm{\ensuremath{\Psi}}}_{\mathrm{\ensuremath{\theta}}}$ is square integrable. The back-transformation of ${\mathrm{\ensuremath{\Psi}}}_{\mathrm…
An inorganic pyroelectric crystal is predicted to be ferroelectric if it satisfies the structural conditions that no atom within the unit cell be displaced more than about 1 Å from the position it would occupy in the paraelectric state and that the largest such displacement be greater than about 0.1 Å. In addition, th…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFormation and structure of alkyl peroxide complexes of germanium(IV) porphyrins from direct reactions with alkyl hydroperoxides and by photolysis of alkylgermanium(IV) porphyrins in the presence of dioxygenAlan L. Balch, Charles R. Cornman, and Marilyn M. OlmsteadCite this:…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIdeal polymer chains of various architectures at a surfaceM. K. KosmasCite this: Macromolecules 1990, 23, 7, 2061–2065Publication Date (Print):April 1, 1990Publication History Published online1 May 2002Published inissue 1 April 1990https://pubs.acs.org/doi/10.1021/ma00209a03…
Abstract In a series of MSnI 3 compounds (M = K, NH 4 , Rb, Cs, CH 3 NH 3 ) two types of coordination around the central Sn(II) were found by 127 I-NQR and powder X-ray diffraction techniques. They are square pyramidal (for M = NH 4 , Rb) and octahedral (for M = CH 3 NH 3 ). CsSnI 3 , on the other hand, showed a drast…
The electrochromic behavior of amorphous films prepared by electron‐beam deposition has been studied. SIMS analysis has revealed that lithium accumulates in amorphous films during reversible coloring and bleaching in propylene carbonate solution of . When a large quantity of lithium has been injected into films, an ab…
Abstract Processing of ceramics is reviewed from a broad perspective, with emphasis on the predominant powder‐based methods, but with considerable attention to other methods. Major stages of the powder process, from preparation, modification, and handling, to sintering or pressure densification (or postdensification)…
Cyclic diguanylic acid acts as a regulator for cellulose synthase activity in the bacterium Acetobacter xylinum. We report the x-ray crystal structure of the regulator at atomic resolution. The structure contains two independent molecules that adopt almost identical conformations. The two molecules form self-intercala…
ABSTRACT The galvanic corrosion potentials of thirty‐eight different waters were measured on site, using ‘Oliphant’ corrosion cells, for lead‐tin solder coupled to copper. A wide range in corrosion potential was found, and the chloride‐sulphate ratio had the most significant effect on corrosion potential. Tests to red…
Surface diffusion in sapphire and sintering of Al 2 O 3 have been studied under identical firing conditions (1593°C, N 2 ) as a function of MgO solute additions. The effect of MgO on surface diffusion has been investigated directly using the technique of multiple scratch smoothing on the (1123) surface of sapphire. Fo…
The bending beam method for measurements of stress in thin films deposited on an elastic substrate in the form of a thin stripe has been improved by the introduction of a laser beam deflection system and of a laser spot position detector. With this improvement, stress measurements have been performed in situ during th…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and structural characterization of a polyoxovanadate coordination complex with a hexametalate core: [(n-C4H9)4N]2[V6O13{O2NC(CH2O)3}2]Qin Chen and Jon ZubietaCite this: Inorg. Chem. 1990, 29, 8, 1456–1458Publication Date (Print):April 1, 1990Publication History Pub…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhysical gels of aqueous poly(vinyl alcohol) solutions: a small-angle neutron-scattering studyWen Li Wu, Mitsuhiro Shibayama, Saroj Roy, Hidenobu Kurokawa, Laurence D. Coyne, Shunji Nomura, and Richard S. SteinCite this: Macromolecules 1990, 23, 8, 2245–2251Publication Date…
Abstract The chemical microstructural analysis (CMA) developed by Rowland and his school was applied to Valonia and bacterial cellulose and the results compared to those obtained with cellulose from cotton linters. It was found that the surface reactivity of Valonia was very small, roughly one half of that found for b…