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21.
22.
Kazimierz Nikodem Francesca Papalini Susanna Vercillo 《Aequationes Mathematicae》1997,53(1-2):127-140
Summary In this note we establish conditions under which every midconvex set-valued function can be represented as sum of an additive function and a convex set-valued function. These results improve some theorems obtained in [8], [10] and [3]. Some results on local Jensen selections of midconvex set-valued functions are also given. 相似文献
23.
Characterizations of pairs of functions that can be separated by a strongly convex, approximately concave or c-quadratic-affine function are presented. As consequences, stability results of the Hyers-Ulam type are obtained. 相似文献
24.
Mirosaw Adamek Attila Gilnyi Kazimierz Nikodem Zsolt Ples 《Journal of Mathematical Analysis and Applications》2007,330(2):829-835
The concept of generalized convex functions introduced by Beckenbach [E.F. Beckenbach, Generalized convex functions, Bull. Amer. Math. Soc. 43 (1937) 363–371] is extended to the two-dimensional case. Using three-parameter families, we define generalized convex (midconvex, M-convex) functions and show some continuity properties of them. 相似文献
25.
Nikodem J. Pop?awski 《Physics letters. A》2009,373(31):2620-2621
We combine Taub's and Ray's variational approaches to relativistic hydrodynamics of perfect fluids into another simple formulation. 相似文献
26.
Stanis?aw Krompiec Robert Penczek Ewelina Kubik Mateusz Penkala Nikodem Ku?nik 《Tetrahedron letters》2009,50(11):1193-5981
Two new methods for the synthesis of orthoesters and compounds containing an orthoester moiety (dihydroisoxazoles) are presented. Mixed orthoesters of general formulas RC(OR1)(OR2)2 and RC(OR1)(OR2)(OR3) were prepared via addition of ROH (R = Bu or m-methylphenyl) to O-allyl acetals (acrolein acetals: diethyl or cyclic, i.e., 2-vinyl-1,3-dioxanes or dioxolanes). The catalytic systems for these reactions were generated from [RuCl2(PPh3)3] and Na2CO3; {[RuCl2(COD)]x} or {[OsCl2(1,5-COD)]x}, PPh3, and Na2CO3. Compounds containing an orthoester moiety (dihydroisoxazoles) were prepared via tandem isomerization of O-allyl acetals (to O-vinyl acetals) catalyzed by ruthenium complexes followed by cycloaddition to in situ-generated 2,6-dichlorophenylnitrile oxide. 相似文献
27.
M. Nikodem K. Krzempek K. Zygadlo G. Dudzik A. Waz K. Abramski K. Komorowska 《Opto-Electronics Review》2014,22(2):113-117
In this paper we present a novel configuration of an NPR mode-locked Er-doped laser. This new optical setup uses voltage controlled LC cells to replace standard retarders (quarter-and half-waveplates) inside the laser cavity. Using this novel, mechanical-adjustment-free setup a mode-locking was obtained with sub-500 fs pulse duration and an average power exceeding 40 mW. Presented results show that using simple LC cells, an optical layout of an NPR mode-locked laser can be greatly simplified. 相似文献
28.
Evidence for the emission of low intensity X-rays during cathodic polarization of the Pd/D system(s) is presented. The Pd/D system was prepared by charging with electrochemically generated deuterium either palladium foil or palladium electrodeposited from D2O electrolytes. Experimental and analytical procedures are described in detail. 相似文献
29.
Chirped laser dispersion spectroscopy (CLaDS) has been introduced recently as a technique that performs molecular detection based on measurement of optical dispersion. In this paper, a new detection scheme based on chirp modulation (CM) and subsequent phase-sensitive detection is described. CM-CLaDS inherits the full advantages of conventional CLaDS and additionally overcomes some of its limitations. A prototype CM-CLaDS instrument has been developed and characterized in laboratory conditions. The system is based on a distributed feedback quantum cascade laser which operates around 4.52???m and can probe the most intense nitrous oxide (N2O) ro-vibrational transitions. Preliminary performance tests are presented and provide a path/bandwidth normalized minimum N2O detection limit below 100?ppbv?m/Hz1/2. 相似文献
30.
Nikodem J. Popławski 《General Relativity and Gravitation》2012,44(4):1007-1014
The Einstein-Cartan-Sciama-Kibble theory of gravity naturally extends general relativity to account for the intrinsic spin
of matter. Spacetime torsion, generated by spin of Dirac fields, induces gravitational repulsion in fermionic matter at extremely
high densities and prevents the formation of singularities. Accordingly, the big bang is replaced by a bounce that occurred
when the energy density e μ gT4{\epsilon \propto gT^4} was on the order of n2/mPl2{n^2/m_{\rm Pl}^2} (in natural units), where n μ gT3{n \propto gT^3} is the fermion number density and g is the number of thermal degrees of freedom. If the early Universe contained only the known standard-model particles (g ≈ 100), then the energy density at the big bounce was about 15 times larger than the Planck energy. The minimum scale factor
of the Universe (at the bounce) was about 1032 times smaller than its present value, giving ≈ 50 μm. If more fermions existed in the early Universe, then the spin-torsion
coupling causes a bounce at a lower energy and larger scale factor. Recent observations of high-energy photons from gamma-ray
bursts indicate that spacetime may behave classically even at scales below the Planck length, supporting the classical spin-torsion
mechanism of the big bounce. Such a classical bounce prevents the matter in the contracting Universe from reaching the conditions
at which a quantum bounce could possibly occur. 相似文献