Materials Literature
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In order to realize multilevel interconnections of VLSIs, problems in the conventional etch-back planarization of silicon oxide film have been clarified through a detailed study. Also, a new etch-back planarization technique has been developed using silicon nitride films, which is able to form very smooth surfaces. An…
Abstract A systematic analysis of the IR and Raman spectra of Rochelle salt (NaKC 4 H 4 O 6 · 4H 2 O) in terms of the standard frequency correlations, deuteration shift and typical nature (with respect to intensity and width) of bands due to different modes is reported. The bands due to the internal modes (excluding s…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA heteroaromatic trimethylenemethaneFred. Wudl, G. Srdanov, B. Rosenau, D. Wellman, K. Williams, and S. D. CoxCite this: J. Am. Chem. Soc. 1988, 110, 4, 1316–1318Publication Date (Print):February 17, 1988Publication History Published online1 May 2002Published inissue 17 Febr…
Abstract A series of thermotropic liquid crystalline polyesters based on p‐acetoxybenzoic acid, naphthalene dicarboxylic acid, hydroquinone diacetate, and poly(ethylene terephthalate) were prepared via melt polycondensation. The anisotropic melts were studied by means of thermal optical testing, differential scanning…
Abstract Viscosity, Infra‐red, NMR spectral measurement technique, density measurement, and electrical conductivity were used to study the changes that occured during γ‐radiolysis of Nylon 6. It was observed that it undergoes chain scission and crosslinking, but chain scission predominates over crosslinking in air irr…
Abstract The question as to whether fractionation occurs during the crystallization of homopolymers from the pure melt has been addressed by studying linear polyethylene mixtures. Two methods were used. In one procedure, mixtures of well‐defined fractions were crystallized under controlled conditions and the subsequen…
Abstract The hydrolysis of a polycarbonate/polybutylene terephthalate (PBT) blend (50/50) was investigated by immersing molded samples in water baths between 21 and 98°C. Samples were also placed in a 100°C air circulating oven (dry environment). Changes in impact properties, dynamic mechanical properties, molecular w…
A 10 kW CO2 continuous wave laser has been used to modify and refine the near surface microstructure of a ductile iron. The wear properties (evaluated by erosion, abrasion, and scratch tests) of the laser processed and unprocessed surfaces were studied. The wear resistance of laser processed samples is significantly e…
Localized corrosion rates on buried metallic structures have been quantitatively evaluated by detecting the magnetic fields generated by electrochemical reactions. These results were obtained using electrochemical impedance spectroscopy instrumentation modified to include a SQUID magnetometer as the electrical current…
The thermal desorption of thin oxide films on n- and p-type InP has been studied by using x-ray photoelectron spectroscopy. It was found that oxides formed on InP could be completely desorbed at 458 °C without causing surface decomposition. The phosphorus and indium oxides desorbed together within 5°. However, heating…
A natural single crystal of titanomaghemite from Pretoria, South Africa, containing 8.62 wt% Ti and 54.36 wt% Fe as determined by electron-microprobe analysis, has been studied by X-ray diffraction and Mössbauer spectroscopy. A crystal-structure parameter refinement of this titanomaghemite was undertaken, and values f…
Abstract Two models are presented that can simulate two peaks in a temperature‐programmed desorption (TPD) spectrum from a high surface area catalyst at atmospheric pressure: a multisite model and a subsurface diffusion model. The multisite model assumes that the two peaks arise from two distinct adsorption sites on t…
The immediate environment of benthic algae is reconsidered in terms of the substratum and the effect this can have on algal distribution, with particular reference to two freshwater ecosystems. Individual species often exhibit marked preferences for particular substrata, such that their presence in the littoral zone o…
Within the liquid crystalline domain, dihydroxysilicon(IV) octakis(dodecyloxymethyl) phthalocyanine is polycondensed to give a distribution of polysiloxanes. These latter form a mesophase with lamellar order. For the first time polycondensation has been carried out in a columnar mesophase and a new type of oligomeric…
Abstract The thermal degradation of a double‐base propellant has been studied to elucidate the rate‐determining steps and the kinetic mechanism in a wide range of temperatures (60°C–200°C) by using modified Taliani test, thermogravimetry (TG), and temperature‐varied Abel (TVA) test. The results indicate that the degra…
Abstract Anion radical salts of bis[1,2,5]thiadiazolotetracyanoquinodimethan (BTDA) containing forty kinds of alkylammonium ions were prepared whose molar ratios are unique for each cation and changed from 1:1 (2A–2L) to 2:3 (2M–2Z), 1:2 (2a–2m), and 2:5 (2n) with elongation of the side chains. The electrical conducti…
A method for the analysis of x-ray diffraction spectra of metallic superlattices using the Monte Carlo technique is presented. Using 'statistical' model of a nonideal superlattice, computer simulation of X-ray spectra has been carried out. The proposed model takes into account a random distribution of superlattice per…
Silver-sodium ion exchange is a commonly used method for making waveguides in glass. This paper discusses two exchange media, KNO(3):AgNO(3) and AgNO(3) in NaNO(3):KNO(3) which increase the flexibility of the process and decrease its cost. Exchange in the KNO(3):AgNO(3) can be performed at temperatures as low as 150 d…
Leitung von Prof. Wolfgang Paul konzipierte und erbaute 500 MeV-Elektronensynchrotron in Betrieb. Es war der erste Elektronenbeschleuniger in Europa, der das damals gerade von Courant, Livingston und Snyder entdeckte Prinzip der starken Fokussierung verwendete. Das Hauptforschungsgebiet lag in den ersten Jahren auf Me…
Electrochromic nickel oxyhydroxide films were formed by an electrodeposition method from 0.005 M NiSO 4 +0.015 M (NH 4 )SO 4 solution, and their memory characteristics, response time and operation lifetime were investigated. The films prepared were porous with a network structure. They were colorless and transparent i…