Materials Literature
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Li, substituting for K in KTa${\mathrm{O}}_{3}$, creates a local electric dipole, due to its off-center position with respect to the cubic site. We have studied such crystals with different amounts of Li (and in a few cases also doped with Nb, substituting for Ta) by nuclear magnetic resonance, dielectric relaxation,…
The dielectric properties of condensed matter do not in general follow the Debye model so that, to account for the actual behaviour in solids, distributions of relaxation times have been postulated. It is shown that the frequency response of all solids has common features which can be generalized to give a correct pic…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStandards for nanosecond fluorescence decay time measurementsRoger A. Lampert, Leslie A. Chewter, David. Phillips, Desmond V. O'Connor, Anthony J. Roberts, and Stephen R. MeechCite this: Anal. Chem. 1983, 55, 1, 68–73Publication Date (Print):January 1, 1983Publication Histor…
X-ray diffuse scattering studies of the quasi one-dimensional blue bronzes K0.30MoO3 and Rb0.30MoO3 show that the metal insulator phase transition observed at Tc = 180 K is accompanied by a periodic lattice distortion. Analysis of the diffuse scattering observed well above Tc shows that the lattice instability involve…
Abstract Soil was collected in 30‐cm depth increments to 90 cm from beneath Prosopis glandulosa Torr. var. glandulosa (L. Benson) M. C. Jtn. (mesquite) and from the nonvegetated area between mesquite trees in a phreatophytic stand in the Sonoran Desert of southern California. Total N, NO ‐ 3 ‐N, NH + 4 ‐N, organic C,…
Abstract The 36‐amino acid avian pancreatic polypeptide has been studied by x‐ray analysis at 0.98‐Å resolution and refined using a restrained least‐squares technique to an agreement factor of 15.6%. The polypeptide, which has a compact globular structure with a hydrophobic core, comprises a polyproline–like helix (re…
The strong linear coupling of the director ň to electric field E in ferroelectric liquid crystals can be utilized to perform high-speed electro-optic switching suitable for device applications. In this article we summarize the current understanding of the high-speed, bistable, threshold-sensitive electro-optic effects…
Article Observations on the Diatom Genus Donkinia Ralfs in Pritchard II. Frustular Studies and Intraspecific Variation was published on January 1, 1983 in the journal Botanica Marina (volume 26, issue 12).
Reactions photosensibilisees par Ru(bpy) 3 2+ du benzyl-1 dihydro-1,4 nicotinamide avec divers composes carbonyles aromatiques conduisant a des composes d'addition 1:1 de structure nicotinamide substitue en 4. Rendements moderes. Reduction nulle ou faible en alcools correspondants. Avec la carbonyle-2,2'-bis pyridine…
Four families of diatoms, well represented in the ice microflora of Manitounuk Sound, Hudson Bay, are treated. The Entomoneidaceae (Entomoneis, 6 taxa; Plagiotropis, 2 taxa) and the Nitzschiaceae (Nitzschia, 12 taxa) have more representatives than the Cymbellaceae (Amphora, 1 taxon) and the Gomphonemataceae (Gomphonem…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTExperimental observation of the tellurium(IV) bonding and lone-pair density in dimethyltellurium dichloride by x-ray diffraction techniquesRonald F. Ziolo and Jan M. TroupCite this: J. Am. Chem. Soc. 1983, 105, 2, 229–235Publication Date (Print):January 1, 1983Publication Hi…
Proprietes, mise en œuvre, applications comme couche barriere dans les films, feuilles, bouteilles, tubes dans l'emballage
Aux îles Kerguelen, les monoraphidées sont représentées par les deux genres, Cocconeis et Achnanthes. 35 taxons ont été inventoriés, dont 2 nouveaux pour la science. La plupart des espèces et des variétés ont été examinées au microscope optique, au microscope électronique à balayage et au microscope électronique à tra…
Measurements of the low-energy satellites of the core X-ray photoemission lines of silver and gold are presented. The results are compared with electron energy loss spectra and dielectric measurements. Interpretation of the results on the basis of plasmon excitation is given and compared with earlier interpretations.
Photophysical properties (fluorescence spectra, lifetimes, triplet–triplet absorption spectra, triplet lifetimes and quantum yields) and redox potentials have been measured for the free-base, Zn2+ derivatives of a cationic water-soluble porphyrin, tetrakis(trimethyl-aminophenyl)porphyrin [TAPP(4+)]; the values are sim…
Two new compounds Cs4SnBr6 and Cs4SnCl6 have been prepared and the CsBr–SnBr2 phase diagram is described. Phases of the type Cs4Sn1 –nPbnBr6 –xClx(where n= 0–1, x= 0–6) have been examined by X-ray diffraction, electrical conductivity, Mössbauer spectral, and optical reflectance techniques. The electrical conductivity…
The electrical conductivity of polymers must be understood in order to improve their performance as electrical insulators. At the present time, there is a need to produce materials with lower conductivity than is currently available without compromising the desirable mechanical properties in order to satisfy the conti…
Based on a cost analysis of uranium extracted from seawater, it is concluded that the world’s energy requirements for the next 5 billion years can be met by breeder reactors with no price increase due to fuel costs.(AIP)
Abstract Alfalfa ( Medicago sativa L.) was established at two field locations in Colorado in 1976 and triple superphosphate applied at rates of 25 and 50 kg P/ha annually or 75 kg/ha in a single application at seeding. The initial P applications were incorporated while subsequent applications were topdressed. Soil pro…
Ferrites for inductors and transformers , Ferrites for inductors and transformers , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی