Materials Literature
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Abstract Reduction of 3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene (Me8[14]diene) with sodium borohydride yields three diastereomeric Me8[14]anes. These diastereomers can be separated through fractional crystallization from xylene. The structure of these isomers has been established on the…
Abstract Der Einfluß von gasförmigem HCl und Stickstoff auf die Hochtemperatur‐Korrosion in Atmosphären mit niedrigem Sauerstoffpartialdruck wurde untersucht. Untersuchungen mit der Legierung Fe‐20Cr in He‐H 2 ‐H 2 O‐HCl‐Atmosphären bei 1173 K unter Bedingungen, bei denen keine kondensierten Chloride gebildet werden,…
We have studied the effects of perpendicular electric and magnetic fields on a liquid-crystal sample aligned between glass plates. One field is applied to stabilize the initial alignment, and the other is applied in order to drive the transition; the field and initial alignment directions define six possible geometrie…
Abstract Asymmetrically substituted, liquid‐crystalline phthalocyanines were synthesized. They contain one methoxy, six dodecyloxy and one acryloyloxy‐ or methacryloyloxydodecyloxy groups. The latter functions were polymerized under free radical conditions to give polymers with molecular weights between 9000 and 47000…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDirect observation of .eta.2-arene complexes of [(C5Me5)Rh(PMe3)]William D. Jones and Lingzhen DongCite this: J. Am. Chem. Soc. 1989, 111, 23, 8722–8723Publication Date (Print):November 1, 1989Publication History Published online1 May 2002Published inissue 1 November 1989htt…
The physical mechanism of photostimulated luminescence (PSL) of RbBr:Tl, resulting from x-ray irradiation, has been investigated. Spectroscopic methods have been utilized to identify the bromine F center as the occupied electron trap. By means of absorption studies the charge state of the dopant Tl was found to be mon…
A mathematical model for the initiation of crevice corrosion on 304 stainless steel in was developed. The central concept is that thiosulfate ions, formed by dissolution of inclusions and trapped within the crevice, act in concert with chloride ions to cause passivity breakdown when their concentrations exceed critica…
Recently, a tiling derived from the well-known 2D quasi-periodic octagonal tiling has been introduced. In this letter, we show that in the framework of a tight-binding model, the electronic spectrum of this nontrivial tiling can be derived. The integrated density of state is singular and can be a devil staircase, ther…
In the past, it has been shown that reasonably good estimates of critical cooling rates for glass formation could be obtained by computing the cooling curve which just passes through the nose of a T‐T‐T (time—temperature—transformation) diagram. Also, it has been noted that critical cooling rates found by this procedu…
The authors discuss the modeling and fabricating miniature, vacuum, field-emission diodes and triodes for use in electronics in hazardous environments. They are micrometer-sized devices that are fabricated on a semiconductor wafer using integrated-circuit fabrication techniques and that use field emission rather than…
Attenuated total reflectance Fouriertransform infrared (ATR‐FTIR) spectra were measured in the region from 4300 to 400 cm −1 for a hydrated Na 2 O–SiO 2 glass containing 35 wt% water. The Si–OH bending vibration mode was observed. It was found that the incorporated water, molecular water as well as hydroxyls, affected…
The metabolic pathways of poly(3-hydroxybutyrate) (PHB) and polyphosphate in the microorganism Alcaligenes eutrophus H16 were studied by H, C, and P nuclear magnetic resonance (NMR) spectroscopy and by conventional analytical techniques. A. eutrophus cells accumulated two storage polymers of PHB and polyphosphate in t…
As‐received, yttria‐doped (4.2 wt% Y 2 O 3 ) single crystals of zirconia were heated to ≥2100°C in air. Cube‐shaped samples with faces perpendicular to 〈100〉 axes on the basis of the pseudocubic symmetry were cut from the crystals. X‐ray and electron diffraction indicated that the crystals are polydomain with [001] ax…
The shrinkage rates of small prismatic dislocation loops in thin foils of sapphire (α‐Al 2 O 3 ) have been determined using transmission electron microscopy; between observations the thin foils were annealed ex situ in the temperature range 1200° < T < 1500°C. The shrinkage rates of individual loops were used to…
We report on three compound magnetic and electrostatic lenses for low-voltage applications: an immersion condenser lens, a compound spectrometer objective lens for electron beam testing, and an objective lens for a low-voltage scanning electron microscope (SEM). A common characteristic of all lenses is the electrostat…
Preliminary investigations of the microstructure/mechanical properties relationship in a mollusk shell—the large conch, Strombus gigas —are reported. Strombus gigas has the well‐ordered “crossed lamellar” microstructure and, in four‐point bending, is remarkably tough in certain orientations, permitting noncatastrophic…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStudy of the high-temperature spin-state crossover in the iron(II) pyrazolylborate complex Fe[HB(pz)3]2Fernande Grandjean, Gary J. Long, Bennett B. Hutchinson, LaNelle Ohlhausen, Paul Neill, and J. David HolcombCite this: Inorg. Chem. 1989, 28, 24, 4406–4414Publication Date…
Pseudomonas putida PpGl, which carries the CAM plasmid encoding enzymes involved in the degradation pathway of D-camphor, can utilize D-camphor as a sole carbon source. Cytochrome P-450cam and related enzymes participate in the early oxidation steps of D-camphor degradation metabolism. We cloned from a HindIII DNA lib…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTApplication of dynamic photoluminescence spectroscopy to the study of the active surface sites on supported molybdenum/silica catalysts: features of anchored and impregnated catalystsMasakazu Anpo, Masao Kondo, Catherine Louis, Michel Che, and Salvatore ColucciaCite this: J.…
A new and simple substrate for inducing surface-enhanced Raman scattering (SERS) was investigated. This new SERS substrate consists of a solid support, such as a microscope slide, coated with alumina and then covered with silver. The alumina used in this work is an agglomerate-free type available in several submicron…