Materials Literature
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Phason-strained octagonal quasicrystal phases of Mo-Cr-Ni have been studied by electron diffraction and dark-field imaging. The shifting of some of the diffraction spots lowers the symmetry from eightfold to fourfold. Diffraction patterns of the orthogonal twofold axes show that the shifted spots are split along the f…
A procedure for the patterned synthesis of porous Si exhibiting visible luminescence is described. Anodic electrochemical etch of n- or p-type Si in ethanol/HF solution leads directly to porous Si that luminesces with λmax between 750 and 650 nm. Positive and negative patterns of luminescent porous Si are etched into…
The growth of diamondlike films and overlayers by the depsotion of energetic carbon atoms has been investigated by molecular-dynamics simulations. The interatomic many-atom potential suggested by Tersoff is used. The structurel analysis of the grown films shows that there is an energy window between 40 and 70 eV for t…
We have studied the stability of the luminescence from porous Si in the presence of a variety of ambient gases (e.g., N2, H2, forming gas, and O2). Although the optical properties are fairly stable under most conditions, illumination in the presence of O2 causes a substantial decrease in luminescence efficiency. Infra…
Analytic results are presented for the dynamic behavior of sliding charge-density waves (CDW's) and related extended nonlinear systems with randomness. It is shown that, in the limit of long times, a sliding configuration approaches a unique solution. In CDW models, the velocity of this asymptotic solution is periodic…
On the basis of different types of experiments, the authors develop implicitly the model of surface-enhanced Raman scattering (SERS) of adsorbates on metal surfaces. The long-range enhancement by resonances of the macroscopic laser and Stokes field is separated quantitatively from the metal electron-mediated resonance…
The performance of a new type of grid-supplemented corona voltage stabilizer and regulator (TCVSR) device is described. The normal corona wire-plane voltage stabilizer and regulator was provided by a grid above the anode. The slopes of the stabilization curve have been found to be strongly dependent on the grid voltag…
An experimental program was conducted to determine the role of boric acid on the pitting behavior of alloy 600 steam generator tubes. The test solution consisted of 5620 wppm Cl−, 3984 wppm SO4=, and 500 wppm Cu++ yielding a Cl−/SO4= ratio of 1.4. Boric acid was added in amounts of 0, 50, 100, 200, 500, 1000, and 2000…
The fructose-1,6-bisphosphate aldolase gene of Drosophila melanogaster contains three divergent copies of an evolutionarily conserved 3' exon. Two mRNAs encoding aldolase contain three exons and differ only in the poly(A) site. The first exon is small and noncoding. The second encodes the first 332 amino acids, which…
Abstract The paper is concerned with the discussion of the different mechanisms proposed for plasma‐induced (initiated) polymerization. This new approach to polymer synthesis proceeds through a free radical mechanism, but presents some peculiar characteristics. The initiation reaction is practically instantaneous and…
<div class="htmlview paragraph">The demands for longer lifetimes of cars have meant that the durability of radiators has also become more important, particularly with regard to the resistance to external corrosion due to environmental pollution. In this paper corrosion mechanisms, as well as some preventive meas…
Abstract Infrared spectra of uniaxially drawn ß‐PVDF films under the influence of an electric field were registered. The direction and the strength of the applied field were changed in up to 13 cycles. The field‐induced frequency changes of the bands at 445 cm −1 (CF 2 ‐rocking) and 510 cm −1 (CF 2 ‐bending) were stud…
The crystal structure of anhydrous lithium formate, published recently by Kansikas and Hermansson, is in fact that of a quenchable high-temperature modification (LiHCOO-I). The low-temperature modification LiHCOO-II can be obtained by thermal dehydration of the monohydrate, LiHCOO · H 2 O , or by drying it over P 4 O…
Abstract Electrocatalytic reduction of l-cystine (CySSCy) was examined on glassy carbon electrodes coated with the title conductive polymer in which Pt, Pd, Cu, Ag, and Hg thiolates were fixed. Pt and/or Pd thiolate fixed in the polymer behaved as excellent electrocatalytic active sites for reductive cleavage of the s…
A test containing 19 mixed-oxide fuel pins was operated in the Experimental Breeder Reactor II (EBRII) at peak cladding temperatures near 800°C. Two test pins that had been designed to fail at ∼5 at. % burnup and two low-burnup environmental pins failed and then were operated in the run beyond cladding breach mode for…
The formation of coalesced oxide films on atomically clean polycrystalline chromium has been studied with Auger electron spectroscopy and secondary ion mass spectrometry at temperatures between 30C and 400C. The data are consistent with an initialed chemisorption of oxygen on the clean Cr followed by nucleation of chr…
The angular distributions of secondary electrons (incuding Auger electrons) of different energies emitted from polycrystalline silver bombarded with primary electrons (E = 1000 and 2500 eV) were measured with a RFA analyzer equipped with an additional collector (acceptance angle 4). Additionally, the angular distribut…
<div class="htmlview paragraph">High purity die cast magnesium clutch housings and 4WD transfer cases have demonstrated their ability to function in corrosive road salt environments without the use of protective coatings. The weight reduction opportunities offered by magnesium also extend to highly visible compo…
An austenitic stainless steel (AISI 304) pipe weldment, which had been in operation about 45,000 h at 230°C in the Ringhals 1 BWR plant, was characterized using electrochemical sensitization testing methods (electrochemical potentiokinetic reactivation [EPR] and double-loop EPR), as well as transmission electron micro…
The temperature and angular dependences of the EPR spectra of Mg[H2O]6SiF6:Mn2+ crystal were investigated in order to clarify the successive phase transitions and existence of the incommensurate phase. Five successive phase transitions were found to occur, and phase II was found to be incommensurately modulated. The m…