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91.
This study examined how 1 symbol is selected to control the allocation of attention when several symbols appear in the visual field. In Experiments 1-3, the critical target feature was color, and it was found that uninformative central arrows that matched the color of the target were selected and produced unintentional shifts of attention (i.e., involuntary, initiated slowly, producing long-lasting facilitatory effects). Experiment 4 tested whether such selection is the result of an attentional filter or of a competition bias due to a match of incoming information against integrated object representations stored in working memory. Here, the critical feature was shape and color was irrelevant, but matching color arrows were still selected. Thus, features of objects in working memory will bias the selection of symbols in the visual field, and such selected symbols are capable of producing unintentional shifts of attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
92.
93.
The corrosion behaviour of nitrogen-containing austenitic stainless steel in methanol containing different concentrations
of H2SO4, HCl, LiCl and H2SO4 + HCl has been investigated using a potentiostatic polarization method. The cathodic reaction in the H2SO4, HCl and H2SO4 + HCl solutions was proton reduction whereas in the neutral LiCl solution, oxygen reduction was the predominant cathodic
reaction. Active, passive and transpassive behaviours were observed only for higher concentrations of H2SO4 (0.01–2.0 M) due to the inherent water content. A cathodic loop, characterized by measured negative current in the anodic
region, was also observed in solutions, in which the concentration of H2SO4 was 1.0 M or higher. The relative stability of the passive films decreased as the H2SO4 concentration increased, and thus the steel suffered from mild pitting corrosion. In the chloride environment, the rate of
corrosion increased as the Cl− ion concentration increased. The presence of acid along with Cl− ions enhanced corrosion, and the corrosion rate increased significantly. The steel suffered from mild intergranular corrosion
in acidic chloride solutions of methanol. In the H2SO4 + HCl solutions, passive films were only formed when the H2SO4 to HCl concentration ratio was greater than ∼10:1. 相似文献
94.
The removal of Cu(II) by adsorption on fly ash has been found to be concentration, pH and temperature dependent. The kinetics of adsorption indicates the process to be diffusion controlled. The Langmuir constants have been calculated at different temperatures, and the adsorption has been found to be endothermic (ΔH = 15.652 kcal mol?1). The maximum removal is observed at pH 8.0, and variation in adsorption with pH has been explained on the basis of surface ionisation and complexation. 相似文献
95.
Using the symmetry reduction approach we have herein examined, under continuous groups of transformations, the invariance of Einstein exterior equations for stationary axisymmetric and rotating case, in conventional and nonconventional forms, that is a coupled system of nonlinear partial differential equations of second order. More specifically, the said technique yields the invariant transformation that reduces the given system of partial differential equations to a system of nonlinear ordinary differential equations (nlodes) which, in the case of conventional form, is reduced to a single nlode of second order. The first integral of the resulting nlode has been obtained via invariant-variational principle and Noether’s theorem and involves an integration constant. Depending upon the choice of the arbitrary constant two different forms of the exact solutions are indicated. The generalized forms of Weyl and Schwarzschild solutions for the case of no spin have also been deduced as particular cases. Investigation of nonconventional form of Einstein exterior equations has not only led to the recovery of solutions obtained through conventional form but it also yields physically important asymptotically flat solutions. In a particular case, a single third order nlode has been derived which evidently opens up the possibility of finding many further interesting solutions of the exterior field equations. 相似文献
96.
N. K. Acharya P. K. Yadav S. Wate Y. K. Vijay F. Singh D. Kavasthi 《Bulletin of Materials Science》2004,27(5):417-420
Ion irradiation of Si8+ ion beam of 100 MeV was scattered by a gold foil on a Mylar membrane of 25 Μm thickness in the form of film roll (width,
12.5 cm and length, 400 cm) at the Nuclear Science Centre, New Delhi. The characterization of etched nuclear tracks was carried
out by gas permeation measurements. The samples cut from the film roll of required size for permeability measurements were
etched in a controlled manner in a constant temperature bath of 6N NaOH solution. The opening of the conical etched tracks
was characterized by hydrogen gas permeation. 相似文献
97.
The compositions (1 −x)Ag2SO4−(x)BaSO4, wherex=0·01 to 0·6, were prepared by slow cooling of the melt. The extent of the solid solubility of Ba2+ in Ag2SO4 was determined by X-ray powder diffraction and scanning electron microscopy. The bulk conductivity of each sample was obtained
using a detailed impedance analysis. The partial substitution of Ba2+ results in the enhancement of conductivity in compliance with the classical aliovalent doping theory. A simplistic model
based on lattice distortion (expansion) due to partial substitution of Ag+ by the bigger Ba2+ has been considered to explain enhanced conductivity. Beyond solid-solubility limit (5·27 mole%) the BaSO4-dispersed Ag2SO4 conductivity follows the usual trend seen in binary systems. An increase in conductivity in this case is discussed in the
light of interfacial reactions and surface defect chemistry. The maximum conductivity in 20 mole% BaSO4 dispersed Ag2SO4 is due to percolation threshold. 相似文献
98.
Naber J.F. Singh H.P. Tanis W.J. Koshar A.J. Segalla G.L. 《Solid-State Circuits, IEEE Journal of》1992,27(10):1327-1331
An indirect, phase-locked-loop (PLL), GaAs-enhanced frequency synthesizer with 700 ns loop settling time has been developed. The two-chip GaAs insertion reduced the size of an existing synthesizer from 90 in3 to only 30 in3. The 6.0 in×5.5 in.×0.9 in module contains a 400 gate GaAs programmable divider and a sample and hold (S/H) which improved the settling time by 77% and reduced the size by 67% over the current state-of-the-art synthesizer. Furthermore, the divider reduced power dissipation by 9.7 W and the S/H reduced power dissipation by 1.3 W 相似文献
99.
100.
A new seismic support device and its application in piping systems is described. The device, E-BAR (patented), can be cost effectively used for snubber replacement programs, mitigation of hydraulic transients, pipe whip and as a thermal stop. The device has pre-set gaps to allow free thermal movement. During a seismic or other dynamic load event, if the pipe movement exceeds the gap dimension, the device acts as an elastic or elastic-plastic restraint. The device also has a unique design feature for not exceeding the restraint force beyond a specified limit design value. To analyze piping systems with gap supports having elastic-plastic characteristics, modal analysis procedures for both response spectrum and time history methods are developed. The comparison of responses obtained from the procedures with nonlinear time history analysis and test results available in the literature shows excellent correlation. A pilot program conducted for snubber replacement with E-BARs demonstrates that the limit force feature of E-BAR makes them very attractive for snubber replacement. This is because a particular E-BAR with a specified limit design force can be selected, such that, the E-BAR replacing the snubber does not require any modifications be made to the existing support steel and hardware. 相似文献