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Abstract Low‐temperature polymerization of α‐piperidone was carried out by using MAlEt 4 , KAlEt 3 (piperidone), and M–AlEt 3 (where M is Li, Na, or K) as catalysts and N ‐acetyl‐α‐piperidone as initiator. The behavior in polymerization of these catalysts was superior to alkali metal or aluminum triethyl, and a polyme…
Vauquelinite, Pb 2 Cu[CrO 4 PO 4 OH], is monoclinic, with a = 13.754, b = 5.806, c = 9.563 Å, β = 94°34′, space group P 2 1 / n . The crystal analysis of the mineral was determined by the trial-and-error method starting from the atomic positions found in fornacite. The refinement carried out by the least-squares metho…
In extension of previous studies of the mechanism of the action of XO4n− inhibitors of corrosion, the behavior of MoO42− ions has been investigated. This inhibitor was found to exert a noncathodic action in facilitating anodic passivation, but the phenomena are more complex than those exhibited by CrO42−, TCO4−, and M…
Cylindrical magnetic lenses were developed with the aim of energy analysis of electrons. A set magnetic pole-pieces with rectangular apertures was inserted into the bore of the intermediate lens of a usual electron microscope and was used as an analyzer lens. It has a large chromatic aberration constant for off-axial…
Three angular variables which give the relative orientation between two sets of axes have been defined and their angular range specified for important classes of symmetry. All possible orientations are contained within this angular volume. Continuous ranges of orientations require a continuous density function defined…
The Adam–Gibbs and the free-volume theories of polymer-melt viscosity and the glass transition are applied to the infinite polymethylene chain by comparing the exponential terms in the respective viscosity equations: 2.3B / (T − T0) = C / TSc = b / φ. It is shown that the configurational entropy Sc and the free volume…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPorphyrin studies. XXXVI. DeoxophylloerythroetioporphyrinEarl W. Baker, Alsoph H. Corwin, Ernst Klesper, and P. E. WeiCite this: J. Org. Chem. 1968, 33, 8, 3144–3148Publication Date (Print):August 1, 1968Publication History Published online1 May 2002Published inissue 1 Augus…
Abstract Hydroxy-Al and -Fe interlayers were prepared in “mono-mineralic” fine and coarse clay montmorillonite and coarse clay and silt vermiculite at 3°C and 21°C. The formation of hydroxy interlayers was evaluated by X-ray diffraction, cation exchange capacity, and chemical analyses. At comparable particle size and…
1. The photosynthetic pigments of the green subsurface layer (Ostreobium) of The pigments found were chlorophylls a and b, α- and β-carotene, siphonein, traces the brain coral Favia were studied by two-dimensional paper chromatography. of siphonaxanthin and neoxanthin, and an unknown yellow-orange xanthophyll. 2. The…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTProcedure for determining the absorption spectra of mixed photochromic isomers not requiring their separationJoseph Blanc and Daniel L. RossCite this: J. Phys. Chem. 1968, 72, 8, 2817–2824Publication Date (Print):August 1, 1968Publication History Published online1 May 2002Pu…
The electrical conductivity and the Seebeck coefficient of single-crystal and polycrystalline NiO were measured as a function of temperature and of oxygen partial pressure over a large part of the phase field of stable NiO. In the temperature range 1000°–1600°C the electrical conductivity was found to be proportional…
Abstract The effect of past thermal history on the melting behavior of isotactic polypropylene is investigated in some detail. It is shown that a series of stepwise annealing treatments at steadily increasing temperatures will raise the final melting point and will result in a double endothermic peak if the final anne…
Vapor deposition of Sic from methyltrichlorosilane in a fluidized bed and the microstructure of the deposit were studied over a range of deposition temperatures, carrier gas flow rates, and reactant fluxes. The rate‐determining factor for the deposition of Sic was the rate of supply of reactant. The microstructure of…
Abstract The structure of the crystalline complex of poly(ethylene oxide) with mercuric chloride, whose composition is (CH 2 CH 2 O) 4 · HgCl 2 , has been determined by x‐ray diffraction. The unit cell is orthorhombic with the dimensions of a = 13.55 Å, b = 8.58 Å, and c (fiber axis) = 11.75 Å, and the unit cell conta…
Granular structures containing inorganic polyphosphate were found in Micrococcus lysodeikticus. These structures were isolated by fractionation of the bacterial extract obtained by lysing the organisms with lysozyme. The composition of the fraction which was enriched with these structures was found to be: protein, 24%…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReciprocal relations and proximity of bases in flavine adenine dinucleotideD. W. Miles and D. W. UrryCite this: Biochemistry 1968, 7, 8, 2791–2799Publication Date (Print):August 1, 1968Publication History Published online1 May 2002Published inissue 1 August 1968https://pubs.…
Abstract Reduction of reconstituted native type collagen fibrils with sodium borohydride produced a firmly cross-linked polymer as determined by solubility, thermal shrinkage and dissolution, and renaturation studies, and by examination of the denatured protein by ultracentrifugation, gel filtration, polyacrylamide el…
Coupling of the transition dipoles associated with infrared-active vibrations produces one source of frequency shift and splitting of transverse and lingitudinal modes in solids. The intrinsic part of the dipole is distinguished from the induced part, the latter being related to the electronic polarizabilities of the…
The flowing afterglow technique for ion-neutral reaction rate constant studies has been modified to cover a range of gas temperature from 82° to 600°K. The experimental apparatus is described and rate constants for six reactions between 300° and 600°K are reported. The reaction of He+ with N2 is found to have a rate c…
The infrared reflection and transmission spectra of zinc selenide and zinc telluride were investigated at room temperature in the region of the transverse and longitudinal optical phonon frequencies. From the transmission measurements at oblique incidence of vacuum-evaporated films of these materials, the fundamental…