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An extensive study of the configurations 4 f N (5 d + 6 s ), using the methods of Racah, which included the configuration interaction for these two configurations and effective electrostatic parameters for the 4 f -5 d interaction leads to an improved agreement between observed and calculated energies for seven spectr…
A newly discovered diatom species, Skeletonema menzelii, has been isolated from the Western Sargasso Sea. In the light microscope it is distinguished from the closely related species S. costatum and S. tropicum by generally smaller cell size, fragility of the shells, shorter chain length, and irregular spacing of the…
Abstract The phosphorescence from the nylon polymers 6, 66, 11, and 12 has been studied from the aspects of excitation and emission wavelength location and of emission lifetime. In contrast to the other nylons, the 66 polymer exhibits two distinct phosphorescence bands, both of which are sensitive to thermal and photo…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPreparation, chemistry, and structure of the lithium salt of the octamethyldimolybdate(II) ionF. A. Cotton, J. M. Troup, T. R. Webb, D. H. Williamson, and G. WilkinsonCite this: J. Am. Chem. Soc. 1974, 96, 12, 3824–3828Publication Date (Print):June 1, 1974Publication History…
The low power loss and high power threshold properties have been measured on a number of candidate ferrite phase-shifting materials. The low power loss is characterized by /spl mu//sub 0/'', the imaginary part of the diagonal component of the permeability tensor for the completely demagnetized state. /spl mu/sub 0/''…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPlatinum bronzes. IV. Preparation, crystal chemistry, and physical propertiesDavid. Cahen, James A. Ibers, and J. Bruce. WagnerCite this: Inorg. Chem. 1974, 13, 6, 1377–1388Publication Date (Print):June 1, 1974Publication History Published online1 May 2002Published inissue 1…
Image detection noise is a fundamental limitation in picture processing, whether analog or digital. This noise is characteristically signal-dependent and this signal-dependence introduces significant problems in the design of appropriate noise-suppression techniques. This paper outlines some recent results obtained by…
Theoretical calculations of the angular distribution of photoelectrons ejected from the $2p$ subshell of atomic oxygen for photoelectron kinetic energies $0\ensuremath{\le}\ensuremath{\epsilon}\ensuremath{\le}30$ Ry are presented using both Hartree-Fock (HF) and Herman-Skillman (HS) wave functions. Owing to the weakne…
Abstract An orthochlorite (sheridanite) was heated to 610°C to dehydroxylate the hydroxide sheet and to oxidize ferrous iron. The heated sample was shaken for 20 min in a mixed solution of 0·2 N HCl and 0·2 N NaCl to dissolve the dehydroxylated hydroxide sheet. X-ray diffraction, thermal, infrared absorption and chemi…
On the foundations established by previous experimental and theoretical investigations a basic model is constructed for the protonic order-disorder transition in Sn${\mathrm{Cl}}_{2}$ \ifmmode\cdot\else\textperiodcentered\fi{} 2${\mathrm{H}}_{2}$O. This model is comparable to the Slater model of K${\mathrm{H}}_{2}$P${…
New analysis is presented using a unipolar ion-mobility conduction model in planar geometry which solves for the transient behavior of the bulk electric field and space-charge distributions as a function of time and space, as well as the resulting time dependence of the terminal quantities of voltage and current. The…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPreparation, structure, and bonding of two cubane-like iron-nitrosyl complexes, Fe4(NO)4(.mu.3-S)4 and Fe4(NO)4(.mu.3-S2)(.mu.3-NC(CH3)3)2. Stereochemical consequences of bridging ligand substitution on a completely bonding tetrametal cluster unit and of different terminal l…
Three genes, thrA, thrB, and thrC, were previously defined and localized in the threonine locus of Escherichia coli K-12. thrA, thrB, and thrC specify the enzymes aspartokinase I-homoserine dehydrogenase I, homoserine kinase, and threonine synthetase, respectively. A complementation analysis of the threonine cluster u…
Abstract Crystallization kinetics for 12 polymers including polyolefins, polyesters, polyurethanes, polysiloxanes was measured by the evolution of heat in a modified Calvet‐type calorimeter over wide temperature ranges. The results are analyzed in terms of the Avrami equation and a comparison between calorimetric and…
H Herman (ed) New York: Academic Press 1973 pp xi + 398 price $28 This volume contains four contributions: ‘Epitaxial interfaces’ by J H van der Merwe surveys at length lattice mismatch and dislocation formation, but with hardly any mention of real dimensions in real systems. It is therefore not too helpful for the cr…
The complement-derived chemotactics factors, C3a, C5a, and C567, as well as the chemotactic factor obtained from culture filtrates of Escherichia coli, induce release of the lysosomal enzymes, β-glucuronidase and lysozyme, from rabbit peritoneal neutrophils. Under the same circumstances, there is little or no release…
Many of the significant reactions of unsaturated hydrocarbons (hydrogenation, isomerization, carbonylation, oxidation, polymerization) are catalyzed heterogeneously by metals in or near Group VIII or homogeneously by salts and complexes of these elements. Those reactions effected in both systems are discussed in terms…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCyclotetramerization of 2-dimethylamino-4-tert-butylpyrrole. Tetra-tert-butylporphyrinsB. J. Whitlock, H. W. Whitlock, and H. AllesCite this: J. Am. Chem. Soc. 1974, 96, 12, 3959–3965Publication Date (Print):June 1, 1974Publication History Published online1 May 2002Published…
Secondary recrystallization was observed in 0.25mm thick dysprosium sheet having final cold reductions in the range of 40-60% prior to annealing at 1150°C in a dry helium atmosphere. X-ray and etch-pit studies revealed a predominant (0001)[10\bar{1}0] secondary recrystallized texture. Magnetization curves at 4.2 K and…
Single crystals of Ca2BO3Cl grown from CaCl2 flux near 800 °C have space group P21/c and unit-cell constants a = 3.9484 (4), b = 8.692 (2), c = 12.402 (2) A, β = 100.27 (1)°.