Materials Literature
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Fine sialon powders (Si 6‐z Al z O z N 8‐z , Z = 0.3, 0.6) were prepared by nitriding combustion. Silicon powders was reacted with AlN and Si 3 N 4 under 10 MPa of nitrogen gas. The reaction temperature reached above 2000°C and single‐phase sialon powders were synthesized within minutes. The obtained powders were full…
A series of monoclinic C2/c pyroxenes was synthesized along the join CaNiSi 2 O 6 -CaMgSi 2 O 6 (diopside). The crystal structures of these pyroxenes were refined indices were in the range 2.7-3.7%. Cell parameters and mean bond lengths vary linearly as a function of composition along the join. However, the derived tr…
Phase transitions among paraelectric, ferroelectric, ferrielectric and antiferroelectric phases in a chiral smectic liquid crystal, MHPOBC, have been investigated by means of circular dichroism (CD). It was found that the helix undergoes a complex variation through the transitions such as discontinuous jumps and hande…
An approach to measure semiconductor structures for nondestructive submicrometer metrology in the scanning electron microscope (SEM) at low accelerating voltage is described utilizing the collection and measurement of only the backscattered electron signal rather than the more commonly used secondary electron signal.…
The three-dimensional distribution of various types of point defects in diamond crystals has been investigated by means of new photoluminescence tomographic techniques. In relatively perfect natural yellow diamonds the zoned distribution of blue luminescent N3 and blue–green luminescent 463·0 nm centres was mapped. Br…
This study evaluated yams produced on the DREF-3 friction spinning machine using varying core inlet sliver linear densities and output yam core proportions. A long staple, medium micronaire, Acala cotton was spun into 74, 54, and 45 tex yams at constant spinning drum and outlet speeds. Inlet sliver of 1.77, 2.47, and…
Die enge strukturelle Verflechtung von Porphyrin‐ und Porphycen‐System wird mit dem [22]Porphyrin(2.2.2.2) 1/2 besonders augenfällig demonstriert: [22]Porphyrin(2.2.2.2) existiert aus Spannungsgründen nicht als das Isomer mit Porphyrin‐Symmetrie ( D 2 h ) 1 , sondern liegt als gestrecktes Porphycen 2 vor. magnified im…
Abstract A comparison between the entirely statistical and the combined kinetic and statistical model for amine‐epoxy networks, both studied previously in the literature is made. The chemistry studied involves the generation of a secondary site which reacts in the network through chainwise addition rather than the ste…
Prior cathodic polarization was found to increase pit densities on aluminum by a factor of 100 during the first 20 ms of anodic polarization above the pit initiation potential, in at 65°C. Enhancements of the average pit growth current densities were also observed. Immersion of aluminum in solutions of , or followed b…
The structure of a high-pressure polymorph of Mn 3 O 4 has been refined using the Rietveld technique. The structure is confirmed to be isostructural with CaMn 2 O 4 (marokite), but with significant changes caused by the substitution of divalent Mn for Ca in the large triangular channels. The compound crystallizes in P…
The effects of Si and ZrO 2 dopants on the crystallization and phase transformation process in Li 2 O · Al 2 O 3 · 6SiO 2 glasses were investigated using differential thermal analysis, X‐ray powder diffractometry (XRD), and high‐resolution transmission electron microscopy (TEM) interactively. Phase separation was obse…
Abstract An adsorption method for determining the surface area of only the carbon of carbon-coated silica gel has been developed. In this method p-nitrophenol (PNP) was used as an adsorbate owing to its selective adsorbability on a carbon surface. This method was applied to carbon-coated silica gel prepared by a CVD m…
Trotz starker Verdrillung des konjugierten Systems reagiert das Tetrathiafulvalen‐Homologe 1 mit dem Elektronenacceptor Tetracyanchinodimethan zum Dikation 1 2⊕ . In 1 2⊕ [(TCNQ) 4 ] 2⊕ ist das Anthracengerüst eingeebnet, und die Dithiolringe sind 86° gegen die Anthracenebene verdrillt. Die 1:4‐Stöchiometrie des hoch…
NRC publication: Yes
The anodic polarization behavior of the Ag-Hg matrix phase of dental amalgam (gamma 1) and the rate of mercury dissolution were examined as a function of the tin content. The objectives were to determine the effect of tin on the electrochemical behavior and dissolution of mercury and to provide evidence on whether tin…
Abstract Three polypropylene polymer samples possessing three different molecular weight distributions (MWD) ranging from narrow to broad, but having the same melt flow, were studied. The three resins were used to produce uniaxially oriented stretched tapes, which were evaluated for physical properties and morphologic…
Abstract Oxorhenium(V) porphyrins ReO(P)X (X = Cl, Br) or [ReO(P)] 2 O, or trichlororhenium(V) porphyrins ReCl 3 (P) (P = OEP, TPP, TTP, TAP, TCIP, TMP) 2,3 , respectively, are transformed into nitridorhenium(V) porphyrins ReN(P) with hydrazine hydrate in the presence of ethanol, in good yields. The diamagnetic comple…
A model is presented for the light-induced bond-breaking processes in arsenic chalcogenides which, based on theoretical calculations of coordination defects, accounts for the details of recent experimental light-induced electron-spin resonance experiments on amorphous ${\mathrm{As}}_{\mathit{x}}$${\mathrm{S}}_{1\mathr…
The thin films obtained by a spin-coating of soluble co,per phthalocyanines with tetra-alkylthio substituents have been found to have the x kJ) values in the order of magnitude of l0h1 esu. It is almost the same value as that of metallophthalocyanine with an axial ligand, i.e., vanadiumu-oxo phthalocyanine and so on.…
The crystal structure of the Asp-199----Asn mutant of chloramphenicol acetyltransferase (CAT) has been determined to 2.35-A resolution. In wild-type CAT Asp-199 is involved in a fully buried intrasubunit salt bridge with Arg-18, an interaction that is adjacent to the active site. Replacement of aspartate with asparagi…