Materials Literature
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Solution-cast films of a polyurethane based on 4,4′-diphenylmethane diisocyanate (MDI) and 1,4-butanediol (BDO) as the hard segment and poly(propylene oxide) endcapped with poly(ethylene oxide) (PPO-EO) as the soft segment were examined by optical and electron microscopy, electron diffraction, and wide-angle x-ray sca…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPorphyrin electrode films prepared by electrooxidation of metalloprotoporphyrinsK. A. Macor and T. G. SpiroCite this: J. Am. Chem. Soc. 1983, 105, 17, 5601–5607Publication Date (Print):August 1, 1983Publication History Published online1 May 2002Published inissue 1 August 198…
The yield stress of nylon 6 (Ny6) composites filled with ultrafine and micron-sized (SiO2 and glass) particles was measured as a function of temperature, rate of strain, and filler content. The yield stress of the composites filled with ultrafine SiO2 particles increased with filler content and decreased with filler s…
Based on the existence of a yield surface and a memory surface which represents the maximum stress state the material ever experienced, a plasticity model is proposed to describe the inelastic behavior of metal. By choosing the initial locations and sizes of these two surfaces based on the internal structure and the l…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe first triple-decker sandwich with a bridging benzene ringAlan W. Duff, Klaus Jonas, Richard Goddard, Hans Juergen Kraus, and Carl KruegerCite this: J. Am. Chem. Soc. 1983, 105, 16, 5479–5480Publication Date (Print):August 1, 1983Publication History Published online1 May…
Angle-resolved inverse photoemission with tunable photon energies has been used to map out the unoccupied bands of graphite and lithium-intercalated graphite. At the Brillouin zone center the bottom of the lowest band is found at 4.0\ifmmode\pm\else\textpm\fi{}0.5 eV above the Fermi level in graphite. This band shows…
We consider the magnetic field and temperature dependences of the spin splitting for an electron localized on a shallow donor, taking into account the $s\ensuremath{-}d$ coupling with the surrounding magnetic ions. We calculate the probability distribution of the spin splitting $\ensuremath{\Delta}$ with the thermodyn…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructural and mechanical properties of agar/gelatin co-gels. Small-deformation studiesA. H. Clark, R. K. Richardson, S. B. Ross-Murphy, and J. M. StubbsCite this: Macromolecules 1983, 16, 8, 1367–1374Publication Date (Print):August 1, 1983Publication History Published onlin…
A simple method for determination of ammonium in semimicro‐Kjeldahl analysis of soils and plant materials using a Tecator or Technicon 40‐tube block digester is described. It involves use of an inexpensive steam distillation apparatus that permits direct distillation of ammonium from the tubes used for Kjeldahl digest…
The deposition of amorphous hydrogenated hard carbon (a–C:H) thin films from benzene vapor in a rf plasma is described. a–C:H was deposited on glass, quartz, Si, Ge, and GaAs. Negative self-bias VB and gas pressure P are shown to be the two significant parameters for an accurate control of the deposition process. The…
ABSTRACT Within the clear definition of a quick clay as being a soil which has a sensitivity greater than 30 and a remoulded strength less than 0.5 kPa, a general model for quick clay development is presented, based on the influences of various material properties and natural processes on the sensitivity and remoulded…
Abstract The small‐angle x‐ray scattering (SAXS) technique has been used to characterize the detailed microphase structure of two crosslinked segmented polyurethane elastomers. Both copolymers contain trifunctional polypropylene ether triols in the rubbery elastomeric block, but are synthesized with different hard seg…
Abstract Ion-exchange isotherms between hydrotalcite-like compounds (HT) of the NO 3 -, Cl-, and SO 4 - forms and F − , Cl − Br − , I − , OH − , SO 4 2− , CO 3 2− , and Naphthol Yellow S (NYS 2− ) ions were determined, and the spacing and the width of the 003 reflection were measured as a function of HT composition. T…
The results of studies of natural, native, and technical lignins are surveyed. Data are presented on the structures and physicochemical properties of various technical lignins (hydrolytic, sulphite, and sulphate lignins), which constitute the waste of the cellulose-paper and hydrolytic industries. Considerable attenti…
Abstract The identification of carbonate cements in rock sections is accomplished by means of textural criteria. Some of these criteria, relating to crystal fabric, may be modelled graphically in crystal growth diagrams. Existing crystal growth diagrams are oversimplified. Three new crystal growth diagrams are present…
Abstract The title compound and its potassium analog have been prepared from corresponding aqueous solutions of 99 TcO at pH ≈︁ 2 with SO 2 as a reducing agent. An X‐ray structure determination of the Na‐salt showed Tc coordinated to the tetradentate N(CH 2 COO) ligand (NTA). Two Tc‐NTA moieties are joined via two bri…
Angle-resolved photoemission extended fine structure from adsorbate core levels yields complete, accurate surface structures without resort to trial-and-error comparisons to theory. Scattering peaks from individual substrate atoms were observed with use of $\mathrm{S}(1s)$ photoemission from $c(2\ifmmode\times\else\te…
When superconductivity coexists with a spin-density wave (SDW) for the same electrons, both spin-singlet and spin-triplet Cooper-pair amplitudes of comparable magnitude must occur. Physical properties of the coexistence states are strongly affected by the amplitude of spin-triplet Cooper pairs even when the electron-e…
Crystals of 1,9-dimethyladeninium-indole-3-acetate (1:1) complex (I) and 9-(3-indol-3-ylpropyl)-1-methyladeninium iodide (II), an inter- or intramolecular model for the stacking interaction between the tryptophanyl residue and the methylated (or protonated) adenine base, were subjected to X-ray analyses. Nearly parall…
Possibilities and conditions for SEM observations on barium titanate domain structures are discussed. The optimum conditions to observe domains of the samples with no conducting layer are those providing a positive charge on the surface. The samples under study are examined in the secondary electron mode at 2 to 4 kV.…