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941.
Assessed the validity of A. Ellis's (1971, 1973, 1981) contention that being religious was negatively correlated with mental health. 28 very religious, 34 atheist, and 33 religiously-neutral individuals seeking consultation were compared on the frequency and number of 8 reported problems. Contrary to Ellis's prediction, there were no significant differences among the groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
942.
A new system designed to measure the chromatic dispersion of installed single-mode fibres is presented. This system utilises the modulation phase technique but eliminates the reference laser and fibre. A large dynamic range was demonstrated by the measurement of an 81.1 km length of fibre. 相似文献
943.
Droplet formation on Si surfaces bombarded by 10 keV beams from a liquid metal indium ion source has been observed. It has been verified that excess indium is transported in the ion beam, probably in the form of charged droplets. SIMS, SEM and RBS techniques have been used to study the distribution of droplets at the surface. At the specified ion source operating conditions, equilibrium droplet coverage is of the order of 25%. Individual droplets have an average diameter of 0.35 ωm and an average height of 2.2 nm. At a bombardment current density of 0.1 mA cm?2, equilibrium coverage is reached in about 1 s. 相似文献
944.
S. W. Sloan J. R. Booker 《International journal for numerical methods in engineering》1992,33(1):163-196
This paper considers the problem of integrating the constitutive relations for Tresca and Mohr–Coulomb materials under conditions of plane strain. In the case of a Tresca material, we show that the constitutive law may be integrated exactly by assuming the strain rates d?/dλ to be constant. We also derive a semi-analytic method for integrating both types of constitutive law which assumes that the quantities d?/dλ are constant. This approach is motivated by the fact that the exact variation of the strains during a time interval is unknown and leads to a single non-linear equation in λ which can be solved efficiently to yield the unknown stresses. Finally, we compare the results from the analytic and semi-analytic methods with those from a variety of numerical integration schemes. 相似文献
945.
Insights into soot formation processes are gained from chemical sampling and thermocouple probing of co-flowing inverse diffusion flames (IDFs), with the oxidizer in the center. The transition from near-to slightly sooting flames and the effects of flame temperature, fuel concentration, and fuel structure (using methane, ethene, propene and 1-butene) are investigated. The aromatic content of IDFS scales with the fuel's sooting tendency, and suggests that the formation of the aromatic ring is a controlling step in soot formation. In addition to the relatively well-established reactions involving C4 and C2 species, benzene may form directly from two C3 species for fuels that readily produce C3 species during pyrolysis and/or oxidative pyrolysis. The total concentration of growth species increases almost linearly with fuel concentration, but depends more weakly on flame temperature than would be expected if pure pyrolysis governed the intermediate hydrocarbon behavior. 相似文献
946.
Superplastic forming using conventional alloys and product forms may be a cost effective route for component manufacture. In this paper superplastic deformation of Ti-3Al-4V extruded tube is examined in terms of the strain anisotropy, microstructural changes, the texture and the post-formed tensile properties. Superplastic deformation with low flow stresses over a wide range of strain rates was observed. Strain anisotropy and surface roughening occurred during deformation and was associated with the two-phase, aligned and banded microstructure. A small reduction in the tensile properties was found and changes in the texture were noted after superplastic deformation. 相似文献
947.
Summary Styrene polymerization was initiated by methylaluminoxane in the presence of haloalkane. The propagating species are shown by trapping experiments and electron paramagnetic resonance to be both radicals and cations. 相似文献
948.
An averaging circuit model is developed for the class E resonant DC-DC converter regulated at a fixed switching frequency. The regulation is achieved by use of an auxiliary switch. The model is obtained based on the circuit analysis using the Fourier series expansion. Steady-state and small-signal dynamic analysis is presented, which reveals that the DC output is well controlled by the control angle of the auxiliary switch and that there exists a right-half-plane zero in the control-to-output transfer function. The analysis results are verified by the experiments 相似文献
949.
G.W.A.D. 《Microelectronics Reliability》1991,31(1)
950.
Schilling D.L. Milstein L.B. Pickholtz R.L. Bruno F. Kanterakis E. Kullback M. Erceg V. Biederman W. Fishman D. Salerno D. 《Communications Magazine, IEEE》1991,29(11):86-93
Multipath propagation in a broadband CDMA environment is described. A propagation model for broadband spread-spectrum signals is presented. Experimental results relating to the sharing of the band by fixed service microwave users and mobile personal communications network (PCN) users are discussed. Field tests indicate that PCN systems can provide high-quality communications when sharing the spectrum with fixed-service microwave systems in suburban and urban areas 相似文献