Materials Literature
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Abstract The recrystallization of amorphous cellulose at various relative humidities was studied to clarify the relation between the amount of adsorbed water in cellulose and the molecular motion by the DSC method. The initial recrystallization kinetics of amorphous cellulose at various relative humidities were observ…
We report the waveguiding properties of sputtered films of three chalcogenide glasses: As(2)S(3), Ge(28)Sb(l2)Se(60), and Ge(33)As(l2)Se(55), at 1.064microm. Propagation losses of less than 1 dB/cm have been measured for As(2)S(3) films. Delineated guides, as well as films, have been made and studied.
Mechanisms of concentration quenching of green-Cu luminescence in hexagonal ZnS:Cu,Al under cathode-ray excitation are investigated. The observed concentration dependence of the luminescence intensity is explained well by a model assuming complete pairing of donors and acceptors. Interstitial Cu + centers are formed d…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure of potassium calcium hexanitrocuprate(II) at 295.deg.K. Evidence for a static Jahn-Teller distortionShozo Takagi, P. Galen Lenhert, and Melvin D. JoestenCite this: J. Am. Chem. Soc. 1974, 96, 21, 6606–6609Publication Date (Print):October 1, 1974Publication History…
Ultrasonic velocity measurements have been made on liquid Mg, Ca, Sr, and Ba to temperatures ~300 °C above the melting points. An empirical relationship between the sound velocity and surface tension is tested and found to hold well for the alkaline earth metals. Simple model calculations of the compressibilities at t…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSpin delocalization in square-planar spin-triplet benzene- and toluenedithiolatecobaltate(III)P. J. Van der Put and A. A. SchilperoordCite this: Inorg. Chem. 1974, 13, 10, 2476–2481Publication Date (Print):October 1, 1974Publication History Published online1 May 2002Publishe…
The eutectic between ZrO 2 and MgO was located at 27 wt% MgO. Directional solidification of this composition yields MgO rods in a cubic ZrO 2 matrix. Plane front growth occurred at solidification rates of <2.0 cm/h. The interfiber spacing was proportional to the inverse square root of the solidification rate. In sa…
A study is reported of the effects of the method of conversion of a fibre web into a non-woven fabric and of various constructional parameters on the air-permeability of the resultant fabric. It is shown that, within the ranges of measurement made, the factor most closely related to the air-permeability was the fabric…
Low energy (E &lt;2 eV) photoelectron transmission data have been obtained for thin hydrocarbon films at 77°K as a function of film thickness, which has been varied in steps of 10–70 Å. The photocurrent data approximate exponential attenuation which yield low energy range values which vary from 7 (n-nonane) to 82…
Abstract K 6 Co 2 O 7 ist ein weiteres neues Oxid mit Co IV (rotviolette Einkristalle). Nach Präzessions‐ und WEISSENBERG‐Aufnahmen hegt P2 1 /c vor; a = 6,58 5 , b = 9,12 3 , c = 11,47 9 Å, β = 127,1°. Strukturbestimmend sind Co 2 O 7 ‐Gruppen (zwei über eine gemeinsame Spitze verknüpfte Tetraeder, Symmetrie ≈ S 6 ).…
Abstract : Methods and procedures are presented for estimating nuclear weapon effects pertinent to hardened structures and for designing and analyzing such structures subjected to these effects. Weapon yields considered range from kiloton through multi-megaton size. Overpressure levels which may be treated range from…
Magnetostatic wave propagations in parallel layers of magnetic slabs have been considered. The dispersion characteristics depend strongly on the separation between slabs and their respective crystal plane orientations. The frequency range for nondispersive magnetostatic wave propagation can be extended as compared to…
Machine learning (ML) is transforming all areas of science. The complex and time-consuming calculations in molecular simulations are particularly suitable for an ML revolution and have already been profoundly affected by the application of existing ML ...Read More
Nuclear magnetic resonance (NMR) studies of 7Li ionic motion in four lithium and lithium-potassium silicate glasses of the R2O·4SiO2 and R2O·2SiO2 composition were made before and after heat treatment, and a newly developed equation was used for the analysis of the data. Other data from alkali borate glasses of the 3R…
The Slichter-Ailion (SA) theory for low-field rotating-frame relaxation by atomic diffusion in crystals is applied to a monovacancy mechanism of self-diffusion under the condition that a spin temperature is established between successive jumps of a nucleus but not between successive jumps of a vacancy (so-called high-…
Resonance Raman spectra of copper-porphin in solution have been obtained using the tunable rhodamine 6G dye, Ar+, and HeCd lasers for excitation. Several bands show variation of intensity with excitation wavelength and many combination and overtone bands have been observed with 5145 Å excitation. Depolarization ratios…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMixed-valance diferrocenylacetylene cationCarole LeVanda, Dwaine O. Cowan, Catherine Leitch, and Klaus BechgaardCite this: J. Am. Chem. Soc. 1974, 96, 21, 6788–6789Publication Date (Print):October 1, 1974Publication History Published online1 May 2002Published inissue 1 Octob…
Abstract A new kind of acetal fiber has been discovered which has a tensile strength of 1.7 GPa (250,000 psi) and an elastic modulus of 35 GPa (5 × 10 6 psi). This fiber is produced by a special two‐stage drawing process in the solid state which requires careful control of deformation rate and temperature. Previously…
The advantages of the step-scan mode over a continuous scan in X-ray data collection are discussed. Computer analysis of the recorded profile allows corrections for effects such as non-uniform background, β-filter cut-off, thermal diffuse scattering, and counter dead time, as well as a reduction in the experimental st…
Investigation has been continued of missile impact (116 to 537 meter/sec) upon single layers of high-tenacity nylon fabric by further analyses of high-speed photographs described previously. The results have been compared with prior analogous experiments conducted with yarn bundles of similar material. It appears that…