Materials Literature
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The results of measurements of the proton spin–lattice relaxation time T1 in ice are reported. The ice samples were single crystals grown by zone refining at atmospheric pressure. The measured activation energy for the T1 process is 14.1 ± 0.1 kcal/mole. No anisotropy of T1 is observed. A theoretical calculation of T1…
Spontaneous emission probabilities for electric- and magnetic-dipole transitions from several electronic states of Pr3+ in LaF3 are calculated using the Judd–Ofelt theory and experimental intensity parameters. The calculated radiative decay probabilities are combined with observed fluorescence lifetimes to determine t…
Raman-scattering measurements on K${\mathrm{H}}_{2}$P${\mathrm{O}}_{4}$ reveal a broad, low-frequency ferroelectric mode which can be represented by a simple damped-harmonic-oscillator function. The resultant characteristic frequency and reciprocal zero-frequency susceptibility approach zero while the damping factor r…
Received 29 January 1968DOI:https://doi.org/10.1103/PhysRevLett.20.1045©1968 American Physical Society
Abstract Optically-negative cholesteric liquid-crystal films can be transformed to an optically-positive state by applying high d-c electric fields. A phase transformation occurs in which the helicoidal cholesteric structure is converted to either a planar smectic, or a linear nematic, structure. The threshhold field…
Abstract Mercerized cellulose in the form of 7/2 yarn was reactivated with 17.5% sodium hydroxide and then heated at 100°C. with 5 moles of trityl chloride, in pyridine, per anhydroglucose unit. The time of reaction was varied, giving ether derivatives of the cellulose containing 0.31–0.79 triphenylmethyl groups (DS)…
Abstract : Tables, curves, equations, and example problems presented in the report make it possible, within the range of the experiments, to accurately predict any desired dimensions of the limit of complete rupture.
An approximate solution is obtained for the problem of steady-state longitudinal-wave propagation in anisotropic bars of infinite length and rectangular cross section by employing the variational method of Ritz. The first three dispersion curves are presented for orthotropic, tetragonal, hexagonal, cubic, and isotropi…
Because of its high magnesium content and relatively small anount of silica, iron and aluminum, the weathering process of serpentine rock is very different from other aluminosilicate rocks. Generally it has been thought that podsolization does not occur in the soil derived from this rock.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetics of complex formation between hexacyanoferrate(III) ions and iron(III) to form FeFe(CN)6 (Prussian brown)R. G. Walker and Kenneth O. WatkinsCite this: Inorg. Chem. 1968, 7, 5, 885–888Publication Date (Print):May 1, 1968Publication History Published online1 May 2002Pu…
The temperature and strain rate dependence of the flow stress of ordered and disordered polycrystalline Cu3Au was investigated in the range 20°–420°K. A thermally activated deformation mechanism was observed at temperatures less than ∼100°K and ∼340°K for the ordered and disordered material respectively. For ordered C…
THE USE of dermal grafts in head and neck surgery to protect the carotid artery from "blow outs" and to protect the esophageal suture line against fistulae was introduced by Corso and Gerald in 1963.<sup>1</sup>These authors noted in their report that when there was skin breakdown over the graft it became epithelized…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTShift in Optimal Power Input in an Ultrasonic ReactionScott Fogler and Deveraux BarnesCite this: Ind. Eng. Chem. Fundamen. 1968, 7, 2, 222–226Publication Date (Print):May 1, 1968Publication History Published online1 May 2002Published inissue 1 May 1968https://pubs.acs.org/do…
The cross sections for the reactions 111Cd(n,n′)111mCd, 112Cd(n,2 n)111mCd, 87Sr(n,n′)87mSr, 58Ni(n,p) 58m + gCo, 58Ni(n,2n) 57Ni, and 58Ni[n,d) + (n,np) + (n,pn)] 57Co have been measured by the activation method. Measurements were performed in the energy regions from 2.2 to 3.5 MeV and from 13.7 to 14.8 MeV. The cros…
Abstract A series of model polyurethanes and polyureas, a polyamide, and a polyimide were prepared by reacting 4,4′‐diphenylmethane diisocyanate or polyisocyanates having similar polybenzyl structures with aliphatic or aromatic coreactants. Thermogravimetric analyses indicated that the flammability of the polymers was…
Abstract Viscoelastic properties of uncrosslinked 1,2‐polybutadiene (91.5% vinyl, 7.0% cis , 1.5% trans , number‐average molecular weight 99,000) were studied by dynamic shear measurements between 0.15 and 600 cps (torsion pendulum and Fitzgerald transducer) and shear creep measurements over time periods up to 3.7 × 1…
The amino acid composition of subtilisin Carlsberg has been determined and is in good agreement with the 274 residues found by sequence studies in the protein.From a tryptic hydrolysate, it was possible to resolve the peptides into a series of fractions by gradient elution from Dowex 50.After further purification, the…
Abstract A study was made of the gamma‐ray‐induced copolymerization of tetrafluoroethylene and 3,3,3‐trifluoropropene. Copolymerizations were carried out at 100°C. and 5000 atm. pressure and at 21°C. and various pressures up to 8000 atm. The reactivity ratios calculated from the composition data indicate that the prop…
Abstract Hyperelectronic polarization may be viewed as the electrical polarization in external fields due to the pliant interaction with the charge pairs of excitons, in which the charges are molecularly separated and range over molecularly limited domains. It is particularly pronounced in molecular solids composed of…
It is shown that the threshold of rectified diffusion according to the Hsieh and Plesset solution is in fact frequency dependent when the inertial terms in the equation of motion of the bubble are not neglected. A comparison is made between the threshold calculated from the modified Hsieh and Plesset solution and that…