489 research outputs found
Keys to families of Cladocera and to subfamilies, genera, species and subspecies of Macrothricidae and Moinidae [Translation from: Leningrad, Fauna SSSR, Crustacea 1 (3), 1971]
Identification keys to families of Cladocera and to subfamilies, genera, species and subspecies of Macrothricidae and Moinidae are given. This translation does not include ecological notes or illustrations
Structure of the limbs and its significance for the ecology and systematics of the family Chydoridae. [Translation of: Voprosy Gidrobiologii, p385, 1965]
For an explanation of the dynamics of numbers of chydorids, appearing a massive group in the littoral of fresh water bodies, the structure of the limbs of 29 species was studied
On the sensillae of the limbs of Cladocera. [Translation of: Zoologicheskie Zhurnal 46, 286-288, 1967]
Sensillae of the limbs of Cladocera are described with emphasis on Eurycercus lamellatus
Chydoridae of the world's fauna. [Translation from: Fauna SSSR, Crustacea 1 (2), Nauka, Leningrad, 1971. ]
This translation presents identification keys to the subfamilies, genera, species and subspecies of Chydoridae of the USSR. Chydoridae are a family in the order of Cladocera
Geometric approach to asymptotic expansion of Feynman integrals
We present an algorithm that reveals relevant contributions in
non-threshold-type asymptotic expansion of Feynman integrals about a small
parameter. It is shown that the problem reduces to finding a convex hull of a
set of points in a multidimensional vector space.Comment: 6 pages, 2 figure
Differential Equations for Definition and Evaluation of Feynman Integrals
It is shown that every Feynman integral can be interpreted as Green function
of some linear differential operator with constant coefficients. This
definition is equivalent to usual one but needs no regularization and
application of -operation. It is argued that presented formalism is
convenient for practical calculations of Feynman integrals.Comment: pages, LaTEX, MSU-PHYS-HEP-Lu2/9
Prospects and possibilities of using thermomechanical microrobots for solving technological tasks in space
The possibilities of microrobots for inspection and technological operations on spacecraft board and in open space are analyzed. Utilization of such robots for operations on outer hulls of spacecraft and on internal units and aggregates is discussed
HgCdTe quantum wells grown by molecular beam epitaxy
CdxHg₁₋xTe-based (x = 0 – 0.25) quantum wells (QWs) of 8 – 22 nm in
thickness were grown on (013) CdTe/ZnTe/GaAs substrates by molecular beam epitaxy.
The composition and thickness (d) of wide-gap layers (spacers) were x ∼ 0.7 mol.frac.
and d ∼ 35 nm, respectively, at both sides of the quantum well. The thickness and
composition of epilayers during the growth were controlled by ellipsometry in situ. It
was shown that the accuracy of thickness and composition were ∆x = ± 0.002, ∆d =
± 0.5 nm. The central part of spacers (10 nm thick) was doped by indium up to a carrier
concentration of ∼10¹⁵ cm⁻³
. A CdTe cap layer 40 nm in thickness was grown to protect
QW. The compositions of the spacer and QWs were determined by measuring the Е₁ and
Е₁+∆₁ peaks in reflection spectra using layer-by-layer chemical etching. The galvanomagnetic
investigations (the range of magnetic fields was 0 – 13 T) of the grown QW
showed the presence of a 2D electron gas in all the samples. The 2D electron mobility
µe = (2.4 – 3.5)×10⁵
cm²
/(V·s) for the concentrations N = (1.5 – 3)×10¹¹ cm⁻² (x < 0.11)
that confirms a high quality of the grown QWs
On the equivalence between Implicit Regularization and Constrained Differential Renormalization
Constrained Differential Renormalization (CDR) and the constrained version of
Implicit Regularization (IR) are two regularization independent techniques that
do not rely on dimensional continuation of the space-time. These two methods
which have rather distinct basis have been successfully applied to several
calculations which show that they can be trusted as practical, symmetry
invariant frameworks (gauge and supersymmetry included) in perturbative
computations even beyond one-loop order.
In this paper, we show the equivalence between these two methods at one-loop
order. We show that the configuration space rules of CDR can be mapped into the
momentum space procedures of Implicit Regularization, the major principle
behind this equivalence being the extension of the properties of regular
distributions to the regularized ones.Comment: 16 page
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