Materials Literature
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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…
The electrical resistivity of antiferromagnetic metals due to electron-magnon scattering is calculated on the s-f model in the low temperature region by the use of the variational approach to the Boltzmann equation. The resistivity ρ varies with temperature T as ρ∼T5 for TN ≫T ≫D (TN: Neel tempereture, D: anisotropy e…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTribophosphorescence from nonphotophosphorescent crystalsJeffrey I. ZinkCite this: J. Am. Chem. Soc. 1974, 96, 21, 6775–6777Publication Date (Print):October 1, 1974Publication History Published online1 May 2002Published inissue 1 October 1974https://pubs.acs.org/doi/10.1021/…
Thermal expansion and contraction of single-crystal quartz, 400 mesh quartz powder, and chert were measured with a highly sensitive dilatometer apparatus. Below 560°C expansion characteristics were identical and in agreement with X-ray diffractometer measurements. Between 571 and 573°C single-crystal quartz expanded w…
An attempt is made to characterize the compression properties of fibre masses in terms of two independent parameters,κY and ρ0 derived from van Wyk's theory of fibrous compression. For the wide range of wool samples examined, the compression characteristics are dominated by the κY parameter, the ρ0 parameter having li…
A previous theory of thickening has been extended to encompass the possible dependence of cooperative chain transport on lamella thickness and crystallinity changes during annealing. These have marked effects on the thickening rate leading to changes in slope and departures from straight-line behavior of the plots of…
Abstract Glass formation was investigated in the Na2O–TiO2–P2O5, K2O–TiO2–P2O5, BaO–TiO2–P2O5,Na2O–BaO–P2O5, and Na2O–BaO–TiO2–P2O5 systems. In the Na2O–TiO2–P2O5 system, glass containing up to 45.5 mol% TiO2 was found to be formed at the composition of Na2O/P2O5=1, whereas in the K2O–TiO2–P2O5 system the glass format…
We report on three techniques for replicating relief patterns in dielectric materials for use as substrates for planar integrated optical circuits: embossing with a metal die; casting from a metal die; and casting from a rubber mold. Techniques for overcoating the substrates with light-guiding films and filling of gro…
The relation ΔCpΔκ = TV(Δα)2 is shown to be obeyed under the same assumptions that Davies and Jones used to derive the weaker condition ΔCpΔκ ≥ TV(Δα)2. This means that if a material is found experimentally not to obey the above equality, then it is not describable by an order-parameter theory. A prescription is given…
Abstract Samples of low‐density polyethylene, free from additives, were kept at temperatures between 284° and 355°C under nitrogen containing 1.16% oxygen or less. Changes in molecular weight distribution (MWD) and degree of long‐chain branching (LCB) were followed by gel chromatography (GPC) and viscosity measurement…