Materials Literature
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Abstract The solid‐state viscoelastic properties of polystyrene containing randomly distributed groups of styrene‐ p ‐sodium sulfonate are studied and compared with the corresponding properties of copolymers of styrene and sodium methacrylate (S‐NaMA). The viscoelastic behavior in the primary transition region of thes…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSinglet .dblharw. quintet spin transitions of iron(II) complexes with a P4Cl2 donor set. X-ray structures of the compound FeCl2(Ph2PCH:CHPPh2)2 and of its acetone solvate at 130 and 295 KF. Cecconi, M. Di Vaira, S. Midollini, A. Orlandini, and L. SacconiCite this: Inorg. Che…
Abstract An XPS analysis of a ferricyanide accelerated chromate paint pretreatment film found iron in the form of both a ferricyanide and a ferrocyanide ion. Chromium occurred in at least two different chemical environments, one of which was as a hydrated oxide. Aluminium and fluorine probably occurred together althou…
Symmetries of domain pairs and domain twins are described by black & white space and layer groups, resp. Domain walls (DW s) are represented by paths in order parameter space which determine their structure and symmetry. Symmetry aspects of phase transitions of DW s, lattice pinning of DW s and some properties of DW l…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFlash photolysis study of the metal-metal bond homolysis in dimanganese decacarbonyl and dirhenium decacarbonylR. W. Wegman, R. J. Olsen, D. R. Gard, L. R. Faulkner, and Theodore L. BrownCite this: J. Am. Chem. Soc. 1981, 103, 20, 6089–6092Publication Date (Print):October 1,…
The secondary-electron yield from polycrystalline copper induced by protons, noble-gas ions, and copper ions has been studied as a function of angle of ion incidence in the range 0\ifmmode^\circ\else\textdegree\fi{} to 85\ifmmode^\circ\else\textdegree\fi{}. The experimental results are explained in terms of a recently…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and reactivity of an anionic tetrairon nitrido cluster. Crystal and molecular structure of bis(triphenylphosphin)iminium [dodecarbonylnitridotetraferrate]Douglas E. Fjare and Wayne L. GladfelterCite this: Inorg. Chem. 1981, 20, 10, 3533–3539Publication Date (Print)…
A specific fibril model is presented consisting of bundles of five-stranded microfibrils, which are usually disordered (except axially) but under lateral compression become ordered. The features are as follows (where D = 234 residues or 67 nm): (1) D-staggered collagen molecules 4.5 D long in the helical microfibril h…
Abstract An ab initio LCAO SCF MO calculation was performed on planar Fe‐porphine with a double zeta basis set consisting of 300 CGTO 's. SCF wave functions of several states of Fe‐porphine and its cation were obtained. The net charge of Fe is in the range of 1.39 to 1.53. The highest occupied orbital is ascertained t…
Abstract Free volume fraction of the Williams‐Landel‐Ferry(WLF)‐Doolittle type has been applied to the analysis of the nonequilibrium state for the glassy polymers. The free volume fraction is a two parameter variable since it depends on the free volume and the occupied volume. The excess entropy is derived from the m…
The heat capacity of poly(oxymethylene), poly(oxyethylene), poly(oxytrimethylene), poly(oxytetramethylene), poly(oxyoctamethylene), poly(oxypropylene), Poly(oxymethyleneoxyethylene), poly(oxymethyleneoxytetramethylene), poly(oxy-1,4-phenylene), poly(oxy-2,6-dimethyl-1,4-phenylene), ploy(oxy-2,6-diphenyl-1,4-phenylene)…
Abstract A comprehensive model for a semibatch ester interchange reactor has been developed with a view to investigate the effect of various process and operational variables on the DMT conversion rate as well as the by‐product formation. The influence of important variables such as EG‐to‐DMT ratio, catalyst concentra…
Experimental evidence indicates that up to 90% of all hydrogen is generated at the metal/oxide interface during the corrosion of carbon and low alloy ferritic steels by high temperature water, in the absence of oxygen. None of the presently accepted mechanisms are able to account for this observation. After considerat…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe function of silicon dioxide colloids in photoinduced redox reactions. Interfacial effects on the quenching, charge separation, and quantum yieldsI. Willner, Jer-Ming Yang, Colja Laane, John W. Otvos, and Melvin CalvinCite this: J. Phys. Chem. 1981, 85, 22, 3277–3282Publi…
Strontium-barium niobate, (Sr, Ba)Nb2O6, was hot-pressed and the dielectric, piezoelectric and optical properties of samples with a transmission of 40–52% in a wavelength from 0.35 to 1.4 μm were measured. Anisotropies of about 1.5 times were found in both the permittivity and the electromechanical coupling factor in…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotocontrol of polypeptide helix sense by cis-trans isomerism of side-chain azobenzene moietiesAkihiko Ueno, Keiko Takahashi, Junichi Anzai, and Tetsuo OsaCite this: J. Am. Chem. Soc. 1981, 103, 21, 6410–6415Publication Date (Print):October 1, 1981Publication History Publis…
Organs that are rich in collagen such as liver, lungs, and bone are frequently sites of tumor cell metastasis. In this study, we have found that cultured tumor cells of human and rat origin migrated unidirectionally in response to collagen in vitro. Synthetic di- and tri-peptides that contained amino acid sequences fo…
The structural relaxation rates, which are crucial in understanding the liquid \ensuremath{\leftrightarrow} glass transition, are investigated within the free-volume theory. We discuss the origin of the observed dispersion of relaxation times and show that it is simply related to the dispersion of the total surface-to…
We persent tempeature measurements of the importnt parameter defming the properties of the semctic C* Phase in a series of schiff bases. The pitch of the helica texture is measured optically. The molecular tilt is deduced from optical observations and from X-ray measurements of the smectic layer thickness. The critica…
The solid state reactions that take place between many ceramics and metals can be utilised to produce strong vacuum-tight joints that maintain their strength and durability even at elevated temperatures. In this context platinum can play an especially important role because of its high melting point and resistance to…