1,773 research outputs found
High-frequency oscillations in low-dimensional conductors and semiconductor superlattices induced by current in stack direction
A narrow energy band of the electronic spectrum in some direction in
low-dimensional crystals may lead to a negative differential conductance and
N-shaped I-V curve that results in an instability of the uniform stationary
state. A well-known stable solution for such a system is a state with electric
field domain. We have found a uniform stable solution in the region of negative
differential conductance. This solution describes uniform high-frequency
voltage oscillations. Frequency of the oscillation is determined by antenna
properties of the system. The results are applicable also to semiconductor
superlattices.Comment: 8 pages, 3 figure
Electron Bloch Oscillations and Electromagnetic Transparency of Semiconductor Superlattices in Multi-Frequency Electric Fields
We examine phenomenon of electromagnetic transparency in semiconductor
superlattices (having various miniband dispersion laws) in the presence of
multi-frequency periodic and non-periodic electric fields. Effects of induced
transparency and spontaneous generation of static fields are discussed. We paid
a special attention on a self-induced electromagnetic transparency and its
correlation to dynamic electron localization. Processes and mechanisms of the
transparency formation, collapse, and stabilization in the presence of external
fields are studied. In particular, we present the numerical results of the time
evolution of the superlattice current in an external biharmonic field showing
main channels of transparency collapse and its partial stabilization in the
case of low electron density superlattices
Π£ΡΠ΅Π±Π½ΡΠΉ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡ Π΄Π»Ρ ΠΈΠ·ΡΡΠ΅Π½ΠΈΡ ΡΡΡΡΠΊΠΎΠ³ΠΎ ΡΠ·ΡΠΊΠ° ΠΊΠ°ΠΊ ΠΈΠ½ΠΎΡΡΡΠ°Π½Π½ΠΎΠ³ΠΎ (Π ΠΠ) "Π Π΄ΠΎΠ±ΡΡΠΉ ΠΏΡΡΡ!" ΠΈ ΠΊΠΎΠΌΠΏΡΡΡΠ΅ΡΠ½ΡΠΉ ΡΡΠ΅Π½Π°ΠΆΠ΅Ρ ΠΏΠΎ Π ΠΠ
A description of the nationally oriented training complex for learning Russian as a foreign language "V Dobryi Putβ!" for German speakers which includes a textbook, an audio-supplement, a video-film and a test system is given. The computer-based training system, designed for this complex ensures effective teaching foreign students Russian phonetics, vocabulary, grammar, speech etiquette, and also facilitates the formation of the necessary communication skills.ΠΡΠΈΠ²ΠΎΠ΄ΠΈΡΡΡ ΠΎΠΏΠΈΡΠ°Π½ΠΈΠ΅ Π½Π°ΡΠΈΠΎΠ½Π°Π»ΡΠ½ΠΎ-ΠΎΡΠΈΠ΅Π½ΡΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ ΡΡΠ΅Π±Π½ΠΎΠ³ΠΎ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ° ΠΏΠΎ Π ΠΠ Π΄Π»Ρ Π½Π΅ΠΌΠ΅ΡΠΊΠΎΠ³ΠΎΠ²ΠΎΡΡΡΠΈΡ
"Π Π΄ΠΎΠ±ΡΡΠΉ ΠΏΡΡΡ!", ΠΊΠΎΡΠΎΡΡΠΉ Π²ΠΊΠ»ΡΡΠ°Π΅Ρ ΡΡΠ΅Π±Π½ΠΈΠΊ, Π°ΡΠ΄ΠΈΠΎΠΏΡΠΈΠ»ΠΎΠΆΠ΅Π½ΠΈΠ΅, Π²ΠΈΠ΄Π΅ΠΎΡΠΈΠ»ΡΠΌ ΠΈ ΡΠΈΡΡΠ΅ΠΌΡ ΡΠ΅ΡΡΠΎΠ². Π Π°Π·ΡΠ°Π±ΠΎΡΠ°Π½Π½ΡΠΉ Π΄Π»Ρ Π΄Π°Π½Π½ΠΎΠ³ΠΎ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ° ΠΊΠΎΠΌΠΏΡΡΡΠ΅ΡΠ½ΡΠΉ ΡΡΠ΅Π½Π°ΠΆΠ΅Ρ ΠΎΠ±Π΅ΡΠΏΠ΅ΡΠΈΠ²Π°Π΅Ρ ΡΡΡΠ΅ΠΊΡΠΈΠ²Π½ΠΎΠ΅ ΠΎΠ±ΡΡΠ΅Π½ΠΈΠ΅ ΠΈΠ½ΠΎΡΡΡΠ°Π½Π½ΡΡ
ΡΡΠ°ΡΠΈΡ
ΡΡ ΡΡΡΡΠΊΠΎΠΉ ΡΠΎΠ½Π΅ΡΠΈΠΊΠ΅, Π»Π΅ΠΊΡΠΈΠΊΠ΅, Π³ΡΠ°ΠΌΠΌΠ°ΡΠΈΠΊΠ΅, ΡΠ΅ΡΠ΅Π²ΠΎΠΌΡ ΡΡΠΈΠΊΠ΅ΡΡ, Π° ΡΠ°ΠΊΠΆΠ΅ ΠΎΠ±Π»Π΅Π³ΡΠ°Π΅Ρ ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ Π½Π΅ΠΎΠ±Ρ
ΠΎΠ΄ΠΈΠΌΡΡ
ΠΊΠΎΠΌΠΌΡΠ½ΠΈΠΊΠ°ΡΠΈΠ²Π½ΡΡ
Π½Π°Π²ΡΠΊΠΎΠ²
Fractional and unquantized dc voltage generation in THz-driven semiconductor superlattices
We consider the spontaneous creation of a dc voltage across a strongly
coupled semiconductor superlattice subjected to THz radiation. We show that the
dc voltage may be approximately proportional either to an integer or to a half-
integer multiple of the frequency of the applied ac field, depending on the
ratio of the characteristic scattering rates of conducting electrons. For the
case of an ac field frequency less than the characteristic scattering rates, we
demonstrate the generation of an unquantized dc voltage.Comment: 6 pages, 3 figures, RevTEX, EPSF. Revised version v3: corrected typo
ΠΡΠ΅Π·Π΅Π½ΡΠ°ΡΡΡ ΡΠΌΠ΅Π½Π½ΠΈΠΊΡΠ² singularia ΡΠ° pluralia tantum Ρ ΠΊΡΡΡΡ ΡΠΎΡΡΠΉΡΡΠΊΠΎΡ ΠΌΠΎΠ²ΠΈ ΡΠΊ ΡΠ½ΠΎΠ·Π΅ΠΌΠ½ΠΎΡ
This article considers singularia and pluralia tantum nouns; despite the absence of this topic in programs on teaching Russian as a foreign language (RFL), it must be acknowledged that singularia tantum nouns constitute a significant layer of vocabulary and are quite commonly used, and pluralia tantum nouns are closely linked to cultural discourse and cannot be painlessly excluded from lexical system of the Russian language. Although this phenomenon has been thoroughly studied in classical editions of Russian grammar, problems of category of number and in particular singularia and pluralia tantum nouns are still widely discussed by modern linguists (as is noted, complex subjects can be designated both as forms of singular and forms of plural, therefore the three groups of nouns can be found: pluralia tantum (a single object indicated by plural: Π²ΠΎΡΠΎΡΠ°), a full-numbered paradigm (one object is indicated by singular: ΡΠ°ΠΊΡΡΠΊΠ°), and nouns with a paradigm fluctuation (one object is indicated by both singular and plural: Π΄Π²Π΅ΡΡ / Π΄Π²Π΅ΡΠΈ); there is a dramatic rise in the use of plural forms of many abstract nouns (ΡΠΈΡΠΊ, ΠΏΡΠΎΠ΄Π°ΠΆΠ°) forming a crucial change in the development trend of Russian abstract noun number paradigms). We assume that in RFL teaching, it is important to follow the principles of step by step presentation of theoretical information on this topic (common singularia and pluralia tantum nouns, their grammatical properties, derivative characteristics; proper singularia and pluralia tantum nouns; synonymy, antonymy, and homonymy of singularia and pluralia tantum nouns; occasionalisms, etc.) to help students reach a higher level of Russian language proficiency.Π£ ΡΡΠ°ΡΡΡ ΡΠΎΠ·Π³Π»ΡΠ½ΡΡΠΎ ΡΠΌΠ΅Π½Π½ΠΈΠΊΠΈ singularia ΡΠ° pluralia tantum. ΠΠ΅ Π·Π²Π°ΠΆΠ°ΡΡΠΈ Π½Π° Π²ΡΠ΄ΡΡΡΠ½ΡΡΡΡ ΡΡΡΡ ΡΠ΅ΠΌΠΈ Ρ ΠΏΡΠΎΠ³ΡΠ°ΠΌΠ°Ρ
Π²ΠΈΠΊΠ»Π°Π΄Π°Π½Π½Ρ ΡΠΎΡΡΠΉΡΡΠΊΠΎΡ ΠΌΠΎΠ²ΠΈ ΡΠΊ ΡΠ½ΠΎΠ·Π΅ΠΌΠ½ΠΎΡ (Π΄Π°Π»Ρ β Π Π―Π), ΡΡΠ΅Π±Π° Π²ΠΈΠ·Π½Π°ΡΠΈ, ΡΠΎ ΡΠΌΠ΅Π½Π½ΠΈΠΊΠΈ singularia tantum ΡΡΠ°Π½ΠΎΠ²Π»ΡΡΡ Π·Π½Π°ΡΠ½ΠΈΠΉ ΠΏΡΠΎΡΠ°ΡΠΎΠΊ Π»Π΅ΠΊΡΠΈΠΊΠΈ ΡΠ° Ρ Π΄ΠΎΠ²ΠΎΠ»Ρ Π²ΠΆΠΈΠ²Π°Π½ΠΈΠΌΠΈ, Π° ΡΠΌΠ΅Π½Π½ΠΈΠΊΠΈ pluralia tantum ΡΡΡΠ½ΠΎ ΠΏΠΎΠ²βΡΠ·Π°Π½Ρ Π· ΠΊΡΠ»ΡΡΡΡΠΎΠ»ΠΎΠ³ΡΡΠ½ΠΈΠΌ Π΄ΠΈΡΠΊΡΡΡΠΎΠΌ Ρ Π½Π΅ ΠΌΠΎΠΆΡΡΡ Π±ΡΡΠΈ Π±Π΅Π·Π±ΠΎΠ»ΡΡΠ½ΠΎ Π²ΠΈΠΊΠ»ΡΡΠ΅Π½Ρ Π· Π»Π΅ΠΊΡΠΈΡΠ½ΠΎΡ ΡΠΈΡΡΠ΅ΠΌΠΈ ΡΠΎΡΡΠΉΡΡΠΊΠΎΡ ΠΌΠΎΠ²ΠΈ. Π₯ΠΎΡΠ° ΡΠ΅ΠΉ ΡΠ΅Π½ΠΎΠΌΠ΅Π½ Π΄ΠΎΡΠΈΡΡ ΡΠ΅ΡΠ΅Π»ΡΠ½ΠΎ Π²ΠΈΠ²ΡΠ°Π²ΡΡ Π² ΠΊΠ»Π°ΡΠΈΡΠ½ΠΈΡ
Π²ΠΈΠ΄Π°Π½Π½ΡΡ
ΡΠΎΡΡΠΉΡΡΠΊΠΎΡ Π³ΡΠ°ΠΌΠ°ΡΠΈΠΊΠΈ, ΠΏΡΠΎΠ±Π»Π΅ΠΌΠΈ ΠΊΠ°ΡΠ΅Π³ΠΎΡΡΡ ΡΠΈΡΠ»Π° ΡΠ° ΡΠΌΠ΅Π½Π½ΠΈΠΊΡΠ² singularia tantum ΡΠ° pluralia tantum Π·ΠΎΠΊΡΠ΅ΠΌΠ° ΠΏΡΠΎΠ΄ΠΎΠ²ΠΆΡΡΡΡ ΡΠΈΡΠΎΠΊΠΎ ΠΎΠ±Π³ΠΎΠ²ΠΎΡΡΠ²Π°ΡΠΈΡΡ ΡΡΡΠ°ΡΠ½ΠΈΠΌΠΈ Π»ΡΠ½Π³Π²ΡΡΡΠ°ΠΌΠΈ. ΠΠ°ΠΏΡΠΈΠΊΠ»Π°Π΄, ΡΠ΄Π΅ΡΡΡΡ ΠΏΡΠΎ ΡΠ΅, ΡΠΎ ΡΠΊΠ»Π°Π΄Π½Ρ ΡΠ΅ΡΡ ΠΏΠΎΠ·Π½Π°ΡΠ°ΡΡΡ ΡΠΊ ΡΠΎΡΠΌΠ°ΠΌΠΈ ΠΎΠ΄Π½ΠΈΠ½ΠΈ, ΡΠ°ΠΊ Ρ ΡΠΎΡΠΌΠ°ΠΌΠΈ ΠΌΠ½ΠΎΠΆΠΈΠ½ΠΈ, ΡΠΎΠΌΡ Π²ΠΈΡΡΠ·Π½ΡΡΡΡ ΡΡΠΈ Π³ΡΡΠΏΠΈ ΡΠΌΠ΅Π½Π½ΠΈΠΊΡΠ²: pluralia tantum (ΠΎΠΊΡΠ΅ΠΌΠΈΠΉ ΠΏΡΠ΅Π΄ΠΌΠ΅Ρ, ΠΏΠΎΠ·Π½Π°ΡΠ΅Π½ΠΈΠΉ ΠΌΠ½ΠΎΠΆΠΈΠ½ΠΎΡ: Π²ΠΎΡΠΎΡΠ°); ΡΡ, ΡΠΎ ΠΌΠ°ΡΡΡ ΠΏΠΎΠ²Π½Ρ ΠΏΠ°ΡΠ°Π΄ΠΈΠ³ΠΌΡ (ΠΎΠ΄ΠΈΠ½ ΠΎΠ±βΡΠΊΡ ΠΏΠΎΠ·Π½Π°ΡΠ°ΡΡΡΡΡ ΠΎΠ΄Π½ΠΈΠ½ΠΎΡ: ΡΠ°ΠΊΡΡΠΊΠ°), ΡΠ° ΡΠΌΠ΅Π½Π½ΠΈΠΊΠΈ Π· ΠΊΠΎΠ»ΠΈΠ²Π°Π½Π½ΡΠΌ ΠΏΠ°ΡΠ°Π΄ΠΈΠ³ΠΌΠΈ (ΠΎΠ΄ΠΈΠ½ ΠΎΠ±βΡΠΊΡ ΠΏΠΎΠ·Π½Π°ΡΠ°ΡΡΡΡΡ ΡΠΊ ΠΎΠ΄Π½ΠΈΠ½ΠΎΡ, ΡΠ°ΠΊ Ρ ΠΌΠ½ΠΎΠΆΠΈΠ½ΠΎΡ: Π΄Π²Π΅ΡΡ/Π΄Π²Π΅ΡΠΈ). ΠΠ°Π·Π½Π°ΡΠ°ΡΡΡ, ΡΠΎ Π²ΡΠ΄Π±ΡΠ²Π°ΡΡΡΡΡ ΡΡΠ·ΠΊΠ΅ Π·ΡΠΎΡΡΠ°Π½Π½Ρ Π²ΠΈΠΊΠΎΡΠΈΡΡΠ°Π½Π½Ρ ΠΌΠ½ΠΎΠΆΠΈΠ½Π½ΠΈΡ
ΡΠΎΡΠΌ Π±Π°Π³Π°ΡΡΠΎΡ
Π°Π±ΡΡΡΠ°ΠΊΡΠ½ΠΈΡ
ΡΠΌΠ΅Π½Π½ΠΈΠΊΡΠ² (ΡΠΈΡΠΊ, ΠΏΡΠΎΠ΄Π°ΠΆΠ°), ΡΠΎ Π½Π°Π΄Π·Π²ΠΈΡΠ°ΠΉΠ½ΠΎ Π·ΠΌΡΠ½ΡΡ ΡΠ΅Π½Π΄Π΅Π½ΡΡΡ ΡΠΎΠ·Π²ΠΈΡΠΊΡ ΠΏΠ°ΡΠ°Π΄ΠΈΠ³ΠΌ ΡΠΈΡΠ»Π° Π°Π±ΡΡΡΠ°ΠΊΡΠ½ΠΈΡ
ΡΠΌΠ΅Π½Π½ΠΈΠΊΡΠ² Ρ ΡΠΎΡΡΠΉΡΡΠΊΡΠΉ ΠΌΠΎΠ²Ρ). ΠΠΈ Π²ΠΈΡ
ΠΎΠ΄ΠΈΠΌΠΎ Π· ΡΠΎΠ³ΠΎ, ΡΠΎ Ρ Π²ΠΈΠΊΠ»Π°Π΄Π°Π½Π½Ρ Π Π―Π Π²Π°ΠΆΠ»ΠΈΠ²ΠΎ Π΄ΠΎΡΡΠΈΠΌΡΠ²Π°ΡΠΈΡΡ ΠΏΡΠΈΠ½ΡΠΈΠΏΡΠ² ΠΏΠΎΠΊΡΠΎΠΊΠΎΠ²ΠΎΡ ΠΏΡΠ΅Π·Π΅Π½ΡΠ°ΡΡΡ ΡΠ΅ΠΎΡΠ΅ΡΠΈΡΠ½ΠΎΡ ΡΠ½ΡΠΎΡΠΌΠ°ΡΡΡ Π·Π° ΡΠ΅ΠΌΠΎΡ: Π·Π°Π³Π°Π»ΡΠ½Ρ ΡΠΌΠ΅Π½Π½ΠΈΠΊΠΈ singularia ΡΠ° pluralia tantum, ΡΡ
Π½Ρ Π³ΡΠ°ΠΌΠ°ΡΠΈΡΠ½Ρ Π²Π»Π°ΡΡΠΈΠ²ΠΎΡΡΡ, Π΄Π΅ΡΠΈΠ²Π°ΡΡΠΉΠ½Ρ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠΈ; Π²Π»Π°ΡΠ½Ρ ΡΠΌΠ΅Π½Π½ΠΈΠΊΠΈ singularia ΡΠ° pluralia tantum; ΡΠΈΠ½ΠΎΠ½ΡΠΌΡΡ, Π°Π½ΡΠΎΠ½ΡΠΌΡΡ ΠΉ ΠΎΠΌΠΎΠ½ΡΠΌΡΡ ΡΠΌΠ΅Π½Π½ΠΈΠΊΡΠ² singularia ΡΠ° pluralia tantum; ΠΎΠΊΠ°Π·ΡΠΎΠ½Π°Π»ΡΠ·ΠΌΠΈ ΡΠΎΡΠΎΒ», ΡΠΎ Π΄ΠΎΠΏΠΎΠΌΠ°Π³Π°Ρ ΡΡΡΠ΄Π΅Π½ΡΠ°ΠΌ ΠΏΡΠ΄Π²ΠΈΡΠΈΡΠΈ ΡΡΠ²Π΅Π½Ρ Π²ΠΎΠ»ΠΎΠ΄ΡΠ½Π½Ρ ΡΠΎΡΡΠΉΡΡΠΊΠΎΡ ΠΌΠΎΠ²ΠΎΡ
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