Materials Literature
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The corrosion process for two iron samples of different purities in a molar solution of sulfuric acid has been studied by means of a rotating disk electrode. This study supports the previously formulated hypothesis which assigns the hysteresis, observed when corrosion is low, to the partial coverage (Θ) of the electro…
Barium titanate (BaTiO3) was deposited onto Pt foil, and onto thin-film Pt and Pt-Rh electrodes on sapphire, and counterelectroded to complete metal-dielectric-metal structures. Dielectrics (5000–60 000 Å) were deposited at substrate temperatures from 23 ° to 1000 °C, some fired in air at temperatures to 1400 °C after…
The Monte Carlo technique was applied to the fundamentals of the Electron Probe Microanalyzer (EPMA) and the Scanning Electron Microscope (SEM). A model based on the multiple scattering formula of Lewis was applied to simulate the scattering processes of the primary electrons in the specimen and was exemplified by com…
Expressions are derived for the rotational energy levels of a symmetric top molecule in a 2 E state which take into account a spin-orbit interaction and vibronic Jahn-Teller interactions. Some group theoretical aspects of the Jahn-Teller problem for a general symmetric top molecule are discussed. In addition, the over…
Second-harmonic generation experiments show that large optical nonlinearities are associated with isocyclic and heterocyclic organic groups. The nonlinearities in one compound of the pyrimidine family, 5-Nitrouracil, are estimated to be as large as in barium-sodium niobate.
Abstract The α to γ transition that occurs in nylon 6 upon iodine treatment was investigated by infrared spectroscopy, differential thermal analysis, and x‐ray diffraction techniques. Thin films of nylon (0.2 mil) were treated in either iodine–potassium iodide aqueous solution or in iodine vapor. Very short treatment…
Dispersion equations for shear waves propagating in a nematic liqid crystal are derived from the Ericksen and Leslie's hydrodynamic equations. The complex refection coefficient of a shear wave at a solid-nematic liquid crystal interface is related to effective viscosity coefficients depeding on the orientation of the…
Abstract Clay minerals occur most frequently in a state too finely divided for satisfactory observation with the best optical microscopes, or for study with single-crystal X-ray techniques. The higher resolution made possible by electron-optical instruments can therefore be put to good use in the investigation of the…
Using colloidal iron staining or post-fixation with ruthenium tetroxide it could be evidenced that the interstitial cells on the sensory areas in the inner ear in pigeons produce a fibrillar network sur- rounding every hair bundle of the sensory cells. This network ties the overlying membrane to the surface of the sen…
Phosphorescence microwave double resonance experiments are reported on Zn porphin at 1·2 K. In glassy solution very broad resonance transitions are observed. However, for Zn porphin in a crystalline n-octane matrix—a system known for its sharp optical spectra (Shpolskii effect)—three pairs of microwave transitions wit…
The structure of a new heteroaromatic sulphur compound has been determined; the results support the inclusion of d-orbital in CNDO molecular orbital calculations.
Abstract Molybdäncarbonyl‐Komplexe des NCCN‐Systems (1.4‐Diaza‐butadienDAB) zeigen eine antiparallel zum Grundzustandsdipolmoment gerichtete intensive farbgebende Elektronenanregung, deren an dreiunddreißig meist neuen Verbindungen untersuchte Solvatochromie direkte Aussagen über die Größe der Metall‐Ligand‐Termw…
Structural data and electronic properties argue against the existence of independent chains in the liquid state of tellurium. It is proposed here that the local order consists of sites with 2 or 3 first neighbours, joined by bonds with a strong covalent character. In space, that local order persists up to the second n…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTConformation and segmental motion of native and denatured ribonuclease A in solution. Application of natural-abundance carbon-13 partially relaxed Fourier transform nuclear magnetic resonanceAdam Allerhand, David Doddrell, Victor Glushko, David W. Cochran, Ernest Wenkert, Pe…
The damage and residual strength of 7075-T6 aluminum panels exposed to caliber 0.50 AP M2 gunfire was found to vary with projectile velocity, impact angle, and target thickness. Maximum damage occurred at low velocities and high impact angles. The strength of thin panels agreed closely with fracture theory because of…
Aqueous solutions of LiNO2, NaNO2, KNO2 and CsNO2 generate only three Raman lines even though extremely high concentrations are attainable. The relative integrated intensities are proportional to concentration and show no specific cation dependence. The frequencies approach those of the corresponding solid. The halfwi…
Abstract Trimethylsulfonium bromide (CH 3 ) 3 SBr has been prepared; melting range 183‐186°C. Infrared absorption and Raman spectra have been recorded and assigned.
The naphthoquinone acceptors form stable charge-transfer complexes in solutions of aprotic solvents with aromatic hydrocarbons as donors. From the charge-transfer transition energies of the complexes as well as from the polarographic half-wave reduction potentials of the acceptors relative electron affinities of the a…
The thermo-elastic solutions for the case of one heat source near a circular hole in an infinite elastic plate are given in the steady-state condition using the thermal expansion displacement for "zero stresses". It is assumed that the temperature along the edge of this hole is held at zero degree always. Numerical ca…
1,2,3,4-Tetrafluoronaphthalene undergoes nucleophilic and electrophilic substitutions in the fluorocarbon and in the hydrocarbon ring respectively. On treatment with sodium methoxide, hydrazine, and lithium aluminium hydride, the 2-fluorine atom is displaced predominantly. Bromination and nitration yield mixtures of c…