Materials Literature
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The linear- and nonlinear-optical properties of 2-cyclooctylamino-5-nitropyridine (COANP) have been investigated. The refractive indices exhibit strong dispersion and a high birefringence (0.15–0.3) in the visible. The three main refractive indices at λ = 550 nm are na = 1.700, nb = 1.845, and nc = 1.683. The calculat…
Experimental and modeling studies of the free-radical-induced degradation of polypropylene (PP) in the melt phase have been carried out. Experiments have been performed in a single-screw plasticating extruder using a peroxide as the free-radical source. Concentration of the peroxide was in the range 0.01–0.6 wt%. Resu…
SiC‐monofilament‐reinforced SiC or Si 3 N 4 matrix composites were fabricated by hot‐pressing, and their mechanical properties and effects of filaments and filament coating layers were studied. Relationships between frictional stress of filament/matrix interface and fracture toughness of SiC monofilament/Si 3 N 4 matr…
The longitudinal piezoelectric effect induced by a direct current bias field was investigated in PMN:PT family of relaxor ferroelectric ceramics in the frequency range from 0. 1 Hz to 50 kHz. The piezoelectric d 33 coefficient was studied by measuring the strain induced by the applied electric field. Under the 10 kHz…
Our studies, which are aimed at understanding the catalytic mechanism of the alpha subunit of tryptophan synthase from Salmonella typhimurium, use site-directed mutagenesis to explore the functional roles of aspartic acid 60, tyrosine 175, and glycine 211. These residues are located close to the substrate binding site…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectron transmission and inner-shell electron energy loss spectroscopy of acetonitrile, isocyanomethane, methyl thiocyanate, and isothiocyanatomethaneA. P. Hitchcock, M. Tronc, and A. ModelliCite this: J. Phys. Chem. 1989, 93, 8, 3068–3077Publication Date (Print):April 1, 1…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEffect of excess charge on band energetics (optical absorption edge and carrier redox potentials) in small semiconductor particlesChong Yang Liu and Allen J. BardCite this: J. Phys. Chem. 1989, 93, 8, 3232–3237Publication Date (Print):April 1, 1989Publication History Publish…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMaking mercury-photosensitized dehydrodimerization into an organic synthetic method. Vapor-pressure selectivity and the behavior of functionalized substratesStephen H. Brown and Robert H. CrabtreeCite this: J. Am. Chem. Soc. 1989, 111, 8, 2935–2946Publication Date (Print):Ap…
Abstract A model is introduced for analyzing diameter variations occurring in glass fibers drawn from preforms. The heat transfer is shown to be radiation‐dominated, and approximate expressions for radiative exchange are developed. The expressions are used in the one‐dimensional governing equations for extensional flo…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOrganometal hydroxide route to [(C5Me5)Rh]4(V6O19)H. K. Chae, Walter G. Klemperer, and V. W. DayCite this: Inorg. Chem. 1989, 28, 8, 1423–1424Publication Date (Print):April 1, 1989Publication History Published online1 May 2002Published inissue 1 April 1989https://pubs.acs.or…
The orientational distribution function of a poled, doped polymer film under stress is measured using polarized second-harmonic generation. The four interface nonlinear boundary conditions are solved, and both the magnitude of the second-order susceptibility and the ratio of the tensor components of the second-order s…
Reduced dimensionality and quantum confinement in conjugated organic and polymer structures enhance the effects of electron correlation on virtual electronic excitation processes and nonlinear-optical responses. A microscopic many-electron description of the third-order susceptibilities γijkl(−ω4; ω1, ω2, ω3) of conju…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRelaxation of self-entangled many-arm star polymersGary S. Grest, Kurt Kremer, S. T. Milner, and T. A. WittenCite this: Macromolecules 1989, 22, 4, 1904–1910Publication Date (Print):April 1, 1989Publication History Published online1 May 2002Published inissue 1 April 1989http…
Poly(vinylidene fluoride) (PVDF) transducers are well suited for use in high frequency pulse-echo ultrasound systems because of their high bandwidth. We analyze the design parameters of PVDF transducers operating in the 100 MHz range using the KLM transducer model. The effect of backing layers, electrode configuration…
The shear stress resistance of cultured human endothelium was investigated on 6 mm polytetrafluoroethylene vascular grafts. Endothelial cell attachment was promoted by precoating the grafts with fibrin glue, which contained human fibronectin and inhibitors of fibrinolysis (aprotinin and tranexam acid). To evaluate the…
Abstract A systematic study of the effect of surface pretreatment of cellulosic fibers and the processing time and temperature on the mechanical properties of the cellulose‐containing polypropylene was undertaken. Using non‐treated fibers, the elastic modulus increased gradually with the cellulose content, typically d…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBis(ethylenedioxy)tetrathiafulvalene: the first oxygen substituted tetrathiafulvaleneT. Suzuki, H. Yamochi, G. Srdanov, K. Hinkelmann, and F. WudlCite this: J. Am. Chem. Soc. 1989, 111, 8, 3108–3109Publication Date (Print):April 1, 1989Publication History Published online1 M…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXT2,3,7,8,12,13,17,18-Octakis(.beta.-hydroxyethyl)porphyrin (octaethanolporphyrin) and its liquid crystalline derivatives: synthesis and characterizationBrian A. Gregg, Marye Anne Fox, and Allen J. BardCite this: J. Am. Chem. Soc. 1989, 111, 8, 3024–3029Publication Date (Print…
CdS and PbS clusters with sizes ranging from a few angstroms to 150 Å can be synthesized in polymers. The dependence of the band gap on the cluster size deviates from the prediction of a simple particle-in-a-box model owing to the breakdown of the effective-mass approximation. Instead, the dependence can be described…
Abstract The structure of synthetic nitro-5,10,15,20-tetraphenylporphyrinato(piperidine)cobalt(III) has been determined by X-ray diffraction method. The results revealed that the porphyrin plane is markedly distorted to nonplanar due to the steric interaction between the axial piperidine and the porphyrin core.