Materials Literature
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The crystal structure and morphology of eutectic carbides are known to strongly determine the mechanical and tribological properties of Cr–Ni white cast irons. In an effort to improve these properties, investigators at the US Bureau of Mines have studied the effects of alloying additions of 0·0–1·8%Si, 0·0–6·7%Ni, and…
A quasi-finite element method for calculation of static fields in media with hysteresis is presented in this paper. The proposed method utilizes vector Preisach hysteresis model to describe the material behavior. Time-stepping technique is employed in which the evolution of the electromagnetic system is traced to comp…
The photochromic dinaphthofurofuran 1 undergoes a base-induced ring opening to yield 2, which instantaneously forms the dark blue dimeric quinone methide 3 on exposure to light. This compound is also the photoproduct of 1 and can react back to it both photochemically and thermally.
Abstract Metall(II) bis‐chelates of 1,3‐dithiole‐2‐thione‐4,5‐dithiolate (dmit) and 1,2‐dithiole‐3‐thione‐4,5‐dithiolate (dmt) undergo in CHCl 3 /CH 3 CN (ratio 1:24) photooxidation to the metal(III) bis‐chelates when irradiated at 313 nm. No side reactions were observed. There is no correlation between the quantum yi…
A new liposoluble porphyrin, 2,7,12,17-tetrahexyl-3,8,13,18-tetramethylporphin(THTMP), and its complexes with divalent (Mg, Co, Ni, Cu, Zn, Cd, Hg) and trivalent (Mn, Fe) metals have been synthesized. The electronic, infrared, and far-infrared spectra of these compounds were obtained in the same nonpolar, noncoordinat…
The forced global greenhouse effect and consequently rising sea levels are discussed. A brief survey of biomineralization processes and laboratory/field work encompassing mineral accretion (MA) is given, which is performed by placing cathodic forms and anodes in sea water or other electrolytes. It is proposed to grow…
Abstract The photolysis of iron carbonyl (Fe(CO) 5 ) adsorbed on titanium dioxide (TiO 2 , anatase) was studied by FT‐IR spectroscopy. When adsorbed Fe(CO) 5 is illuminated by visible and near‐UV light, the IR spectrum of its photolysis products is hardly observed, indicating that most of the Fe(CO) 5 is photodecompos…
In this paper, we consider two-dimensional dendritic growth from pure melt with inclusion of the anisotropy of surface tension. The interfacial wave theory previously established for axisymmetric dendritic growth is extended to this case. The results show that the effect of the anisotropy of surface tension on the sel…
Intergranular stress corrosion measurements have been made on Fe alloys in 1 M sodium sulfate at electrochemical potentials of +750 to +1250 mVSCE and in 55% calcium nitrate at 60°C and +750 mVSCE. Tests were conducted on Fe with variable grain-boundary S and P concentrations ranging from 0.04 to 0.23 monolayers of S…
In addition to conventional chemical etching (CE), electrochemical etching (ECE), is usually required for the initial tiny a tracks in polycarbonate (PC) to enlarge to visible etch pits. A model based on the 'vertical effective range' is proposed. The vertical effective range is a modified concept of the vertical mean…
Using a thermodynamic approach, we examine the role thermal expansion plays in determining the temperature dependence of band gaps and band offsets. Because of the large variation in the standard volume of electrons (or, equivalently, variation in conduction-band deformation potential) with symmetry of the conduction…
The water formation and decomposition reactions on Pt and the presence of intermediate OH were investigated by simultaneously measuring the OH desorption rate (by laser-induced fluorescence) and the overall H2O formation rate at different H2/O2 and H2O/O2 mixtures. These measurements were combined with computer modeli…
A new nortriterpenoid glycoside, named yemuoside [I] was isolated from Stauntonia chinensis. On the basis of chemical and spectral evidence, it structure was determined as 3-O-[alpha-L-arabinopyranosyl-(1----3)-alpha-L-rhamnopyranosyl-(1- ---2)-alpha-L-arabinopyranosyl]-30-noroleana-12,20(29)-di en-28-oic acid 28-O-[b…
Low-temperature thermal conductivity and time-dependent specific heat have been measured on mixed crystals of ${\mathrm{Rb}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$(${\mathrm{NH}}_{4}$${)}_{\mathit{z}}$${\mathrm{H}}_{2}$${\mathrm{PO}}_{4}$ (x=0.35,0.72), in the composition range in which an electric dipole glass state f…
This paper describes the preparation and properties of novel heat- resistant, isocyanate-based polymers. Poly(urethane-oxazolidones) (1/1 molar ratio) were prepared by reaction of NCO-terminated urethane prepolymers with polyepoxides. Poly(urethane-oxazolidone-isocyanurates) (3/3/1 molar ratio) were made by reaction o…
STM (Scanning Tunneling Microscopy) and its variants, collectively called SXM (not including electron microscopy), are being increasingly used in electronics research and industry to study and inspect semiconductor surfaces. While it is possible to obtain quite high depth resolutions, lateral spatial resolution is chi…
The effect of hydrophobic particles on foam stability was quantitatively evaluated by the parameters in the capillary model. Polystyrene particles were dispersed into an ovalbumin solution, foam then being produced by introducing air into the ovalbumin solution with polystyrene particles (OSP) through a spinneret. The…
The symmetries of a function are considered that takes as its argument an arbitrary two-dimensional Bravais lattice, represented by a 2×2 matrix. Rotating the lattice corresponds to multiplying its matrix on the right by an element of SO(2). Matrices related by left multiplication of an element of SL(2,Z) also refer t…
The biraphid pennate genus, Rhoikoneis, originally included species flexed in girdle view with a central nodule on each valve. Recently, this genus was shown to contain taxa belonging to three distinct genera: Rhoikoneis, Campylopyxis, and Rhoicosphenia. Rhoikoneis stands apart from the other two in possessing slit-li…
With few mesogenic chromone derivatives in the literature the synthesis of 7-[4′-n-alkyloxybenzoyloxy) isoflavones was carried out. The resulting homologous series was characterized by elemental analysis and spectroscopic techniques. The first four members of the series only exhibit a nematic phase. In addition to the…