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931.
M. Kopcewicz J. Jagielski A. Grabias F. Stobiecki T. Stobiecki 《Hyperfine Interactions》1998,112(1-4):25-28
The Ar-ion-beam mixing of Fe/Zr bi- and multilayers is studied by conversion electron Mössbauer spectroscopy as a function of ion dose ranging from 1×1014 to 1×1017 at./cm2. The mixing leads to amorphization of the Fe/Zr system. It was shown that the mixing process in bilayers depends strongly on the thickness of the Zr substrate. The amorphization is much more effective and occurs at lower ion doses in multilayers as compared to corresponding bilayers. 相似文献
932.
Semicontinuity and Quasiconvex Functions 总被引:11,自引:0,他引:11
Criteria are derived for quasiconvex functions under lower semicontinuity and upper semicontinuity conditions. The results thus obtained generalize earlier results for convex functions. We also give new conditions under which a given function is r-convex in the sense given by Avriel. 相似文献
933.
We prove the following. Let G be an undirected graph. Every partially specified symmetric matrix, the graph of whose specified entries is G and each of whose fully specified submatrices is completely positive (equal to BBT for some entrywise nonnegative matrix B), may be completed to a completely positive matrix if and only if G is a block-clique graph (a chordal graph in which distinct maximal cliques overlap in at most one vertex). The same result holds for matrices that are doubly nonnegative (entrywise nonnegative and positive semidefinite). 相似文献
934.
A. S. Romanyuk 《Ukrainian Mathematical Journal》1997,49(9):1409-1422
We obtain order estimates for some approximate characteristics of the Besov classes B
p,ϑ
r
of periodic functions of many variables.
Institute of Mathematics, Ukrainian Academy of Sciences, Kiev. Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 49,
No. 9, pp. 1250–1261, September, 1997. 相似文献
935.
936.
A. P. Golub 《Ukrainian Mathematical Journal》1989,41(6):690-694
Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 41, No. 6, pp. 803–808, June, 1989. 相似文献
937.
A simple experimental technique using an instrumented pin was developed for the measurement of the load-contact variation in a clearance-fit, pin-loaded hole. The method is applicable to both conducting and nonconducting materials. 相似文献
938.
In this paper, we introduce a new class of function systems generalizing the classical Faber-Schauder system. Under the condition that the generating sequence is bounded, we show that systems of such a class constitute bases in the space of continuous functions and prove some properties of series expansions of functions in these systems. 相似文献
939.
A. S. Mart’yanov 《Mathematical Notes》2007,82(1-2):57-66
In this paper, we study a dynamic reconstruction algorithm which reconstructs the unknown unbounded input and all unobservable phase coordinates from the results of measurements of part of the coordinates. An upper and a lower bound for the accuracy of the reconstruction is obtained. We determine the class of inputs for which the upper bound is uniform. We give a condition for optimally matching the algorithm parameters, ensuring the highest order of the upper bound and equating the orders of the upper and lower bounds. Thus, we establish the sharpness of the upper bound. 相似文献
940.