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955.
A survey represented mainly by means of glasses of the borosilicate system shows the generally valid limits of the applicability of the crack growth model and the essential influence of the corrosion of glasses on fatigue. A close correlation between macroscopic crack growth and fatigue was affirmed for samples with fresh, slightly corroded cracks. If the state of corrosion of the samples is advanced, the influence of region 2 is reduced and the fatigue limit is increased. Processes of corrosion during the measurement influence the fatigue curve prevailingly in the range of great time-to-failure, in particular the slope in region 1. The results indicate the high complexity of the effective chemomechanical processes during the fatigue measurements. 相似文献
956.
E. Rupp G. Siebler W. Brachmann F. Lehmann B. Lokau M. Berdau W. Schmitz und A. Noll 《Fresenius' Journal of Analytical Chemistry》1925,67(10):409-411
Ohne Zusammenfassung 相似文献
957.
We present a direct and rather elementary method for defining and analyzing one-dimensional Schrödinger operators H = −d2/dx2 + μ with measures as potentials. The basic idea is to let the (suitably interpreted) equation −f′′ + μ f = zf take center stage.We show that the basic results from direct and inverse spectral theory then carry over to Schrödinger operators with measures. 相似文献
958.
We examine domino tilings of rectangular boards, which are in natural bijection with perfect matchings of grid graphs. This
leads to the study of their associated perfect matching polytopes, and we present some of their properties, in particular,
when these polytopes are Gorenstein. We also introduce the notion of domino stackings and present some results and several
open questions. Our techniques use results from graph theory, polyhedral geometry, and enumerative combinatorics. 相似文献
959.
Brajendra K. Singh Christian V. Stevens Davy R.J. Acke Erik V. Van der Eycken 《Tetrahedron letters》2009,50(1):15-4274
A continuous flow procedure has been elaborated for the copper(II)-mediated N- and O-arylation of a range of compounds with arylboronic acids using a commercial microreactor setup. The compounds could be continuously generated in good yields paving the way for efficient scalability. 相似文献
960.
Christian Corda 《General Relativity and Gravitation》2008,40(10):2201-2212
An oscillating Universe which arises from the linearized R 2 theory of gravity is discussed, showing that some observative evidences like the cosmological redshift and the Hubble law are in agreement with the model. In this context Dark Energy is seen like a pure curvature effect arising by the Ricci scalar. 相似文献