Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Recently a dapF mutant of Escherichia coli lacking the diaminopimelate epimerase was found to have an unusual large LL-diaminopimelic acid (LL-DAP) pool as compared with that of meso-DAP (C. Richaud, W. Higgins, D. Mengin-Lecreulx, and P. Stragier, J. Bacteriol. 169:1454-1459, 1987). In this report, the consequences o…
The authors have measured the room temperature Raman spectrum from porous films on silicon substrates. Data from films on degenerate substrates showed a Raman peak at the frequency expected for bulk silicon together with a peak shifted to lower frequencies. This was interpreted in terms of material having, in general,…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSyntheses and magnetic properties of a heteropolyoxotungsten(VI)iron(III) cation and [LFeIII(.mu.-MO4)3FeIIIL] complexes (M = chromium(VI), molybdenum(VI)). Crystal structures of L2Fe2(CrO4)3.cntdot.H2O and [L3Fe3W4O14(OCH3)3](ClO4)2.cntdot.0.5H2O (L = 1,4,7-trimethyl-1,4,7-…
Relaxation of trapped holes that are introduced into silicon dioxide from silicon by the avalanche injection method is studied under various conditions of thermal activation and external electric fields. It is found that the flat band voltage recovery in time follows a universal behavior in that the response at high t…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis, characterization, and x-ray structure of the ruthenium picnic-basket porphyrinsJames P. Collman, John I. Brauman, Jeffrey P. Fitzgerald, Philip D. Hampton, Yoshinori. Naruta, John W. Sparapany, and James A. IbersCite this: J. Am. Chem. Soc. 1988, 110, 11, 3477–348…
BaTiO3 positive temperature coefficient of resistance (PTCR) specimens were made from commercial BaTiO3 which was mixed with 0.35 mol. % of Ho2O3 to make it semiconducting and 0.07 mol. % of MnCO3. After sintering at 1320 °C the samples were annealed in batches at 1220 °C for various periods between 0 and 5 h. The eff…
Fractoemission is the emission of photons and particles due to the fracture of materials. In this paper we present characteristic intensity versus time measurements of photon emission (phE), electron emission (EE), positive ion emission (PIE), and neutral emission (NE) due to the fracture of fused silica and sodium tr…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReactivity of dianionic hexacoordinated silicon complexes toward nucleophiles: a new route to organosilanes from silicaA. Boudin, G. Cerveau, C. Chuit, R. J. P. Corriu, and C. ReyeCite this: Organometallics 1988, 7, 5, 1165–1171Publication Date (Print):May 1, 1988Publication…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBlend miscibility of bisphenol A polycarbonate and poly(ethylene terephthalate) as studied by solid-state high-resolution carbon-13 NMR spectroscopyP. Mark Henrichs, John Tribone, Dennis J. Massa, and James M. HewittCite this: Macromolecules 1988, 21, 5, 1282–1291Publication…
Abstract The growth and dissolution of oxide layers on silicon has been studied under illumination and in the dark by analyzing current transients at different voltages in solutions of NH 4 F of various concentrations at pH values between 1 and 4.5. When the oxidation rate of the silicon at high enough anodic bias and…
A review is given of glow discharge techniques which are useful for conditioning vacuum vessels for high-vacuum applications. Substantial development of glow discharge techniques has been done for the purpose of in situ conditioning of the large ultrahigh vacuum systems for particle accelerators and magnetic fusion de…
The resistance of coarse‐grained alumina to stable crack growth, initiated from “naturally’occurring surface flaws, was studied in strength tests with a bend‐bar technique. The surface cracks experienced R‐curve behavior over the first few hundred micrometers; i.e., the applied crack driving force had to be increased…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOxidation of carbon monoxide on palladium: role of the alumina supportF. Rumpf, H. Poppa, and M. BoudartCite this: Langmuir 1988, 4, 3, 722–728Publication Date (Print):May 1, 1988Publication History Published online1 May 2002Published inissue 1 May 1988https://pubs.acs.org/d…
Polymer films containing dispersions of liquid crystal microdroplets have considerable potential for use in displays and other light control devices. These polymer-dispersed liquid crystal (PDLC) films operate by electric field control of light scattering, rather than by polarization control as in the case of twisted…
Betaine phosphite, an addition compound of the amino acid betaine and phosphorous acid, can be grown in single crystal form from aqueous solutions. Structural, optical, dielectric, and caloric data of this new material are reported. At least two phase transitions are observed in (CH3)3NCH2COO˙H3PO3. The lower one, aro…
Qualitative X-ray microanalysis of biological specimens requires an approach that is somewhat different from that used in the materials sciences. The first step is deconvolution and background subtraction on the obtained spectrum. The further treatment depends on the type of specimen: thin, thick, or semithick. For th…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIn-plane structure of underpotentially deposited copper on gold(111) determined by surface EXAFSO. R. Melroy, M. G. Samant, G. L. Borges, J. G. Gordon II, L. Blum, J. H. White, M. J. Albarelli, M. McMillan, and H. D. AbrunaCite this: Langmuir 1988, 4, 3, 728–732Publication D…
Annealing of polymers below the glass transition temperature results in a decrease in enthalpy that is recovered during heating. The enthalpy recovery is visible as an endothermic peak in a differential scanning calorimetry (DSC) scan. The position of this peak depends on the thermal treatment given and on the structu…
The analytical function of crack extension to a fractional power is used to represent the fracture resistance of a vitreous‐bonded 96% alumina ceramic. A varying flaw size, controlled by Vickers indentation loading between 3 and 300 N, was placed on the prospective tensile surfaces of four‐point bend specimens, previo…
The use of an arterial prosthesis with a tapered lumen has several important advantages; for example, improved stability of flow, increased wall shear and better matching of its size with that of the host vessel. Tapering may, however, lead to increased energy losses, particularly if the angle of taper is large and th…