2,442 research outputs found
Evidence of Josephson-coupled superconducting regions at the interfaces of Highly Oriented Pyrolytic Graphite
Transport properties of a few hundreds of nanometers thick (in the graphene
plane direction) lamellae of highly oriented pyrolytic graphite (HOPG) have
been investigated. Current-Voltage characteristics as well as the temperature
dependence of the voltage at different fixed input currents provide evidence
for Josephson-coupled superconducting regions embedded in the internal
two-dimensional interfaces, reaching zero resistance at low enough
temperatures. The overall behavior indicates the existence of superconducting
regions with critical temperatures above 100 K at the internal interfaces of
oriented pyrolytic graphite.Comment: 6 Figures, 5 page
Quantum charge diffusion in underdamped Josephson junctions and superconducting nanowires
The effect of quantum fluctuations on the current-voltage characteristics of
Josephson junctions and superconducting nanowires is studied in the underdamped
limit. Quantum fluctuations induce transitions between a Coulomb--blockade and
a supercurrent branch, and can significantly modify the shape of
current-voltage characteristics in the case of a highly resistive environment.
Owing to the phase-charge duality, our results can be directly extended to the
opposite overdamped limit.Comment: 6 pages, 2 figures, replaced with published versio
Π‘ΠΈΠ½ΡΠ΅Π· ΡΠ° Π΄ΡΡΡΠ΅ΡΠΈΡΠ½Π° Π΄ΡΡ 8-Π°ΠΌΡΠ½ΠΎΠ·Π°ΠΌΡΡΠ΅Π½ΠΈΡ 7-(2-Π³ΡΠ΄ΡΠΎΠΊΡΠΈ-3-ΠΏ-ΠΌΠ΅ΡΠΎΠΊΡΠΈΡΠ΅Π½ΠΎΠΊΡΠΈΠΏΡΠΎΠΏΡΠ»-1)-3-ΠΌΠ΅ΡΠΈΠ»ΠΊΡΠ°Π½ΡΠΈΠ½Ρ
It has been found that natural xanthines, as well as their synthetic analogs, possess the diuretic effect. Analysis of the literature proves that there is a great opportunity of applying synthetic derivatives of N-methylated xanthines as potential diuretics.Aim. To develop preparative methods of the synthesis of 8-aminosubstituted of 7-(2-hydroxy-3-p-metoxyphenoxypropyl-1)-3-methylxanthine and study their physical, chemical and biological properties. Results. The synthesis of a series of 8-aminosubstituted of 7-(2-hydroxy-3-p-metoxyphenoxypropyl-1)-3-methylxanthine was carried out. According to the results of the biological testing the compounds synthesized belong to the toxicity of class IV. 7-(2-Hydroxy-3-p-methoxyphenoxypropyl-1)-8-(furyl-2-methylamino)-3-methylxanthine xanthine shows the highest diuretic activity, and hence, requires a more in-depth study since it is twice more active than hydrochlorothiazide. It should be emphasized that all compounds synthesized exhibit a marked diuretic effect. Experimental part. 8-Bromo-7-(2-hydroxy-3-p-methoxyphenoxypropyl-1)-3-methylxanthine was obtained by heating 8-bromo-3-methylxanthine with p-methoxyphenoxymethyloxirane in butanol-1 and in the presence of N,N-dimethylbenzylamine. 8-Aminosubstitutied of 7-(2-hydroxy-3-p-metoxyphenoxypropyl-1)-3-methylxanthine was obtained by boiling of bromoalcohol with the primary and secondary amines. The structure of the compounds synthesized was unambiguously confirmed by NMR-spectroscopy. The acute toxicity of the compounds obtained was studied by Kerber method. The study of the diuretic activity of the compounds was carried out using Ye. Berkhin method. Hydrochlorothiazide was used as a reference substance. Conclusions. Simple methods for the synthesis of 8-amino-7- (2-hydroxy-3-p-methoxyphenoxypropyl-1)-3-methylxanthines have been developed. The structure of the compounds synthesized has been confirmed by the method of NMR 1H-spectroscopy. The acute toxicity and the diuretic activity of the compounds obtained have been studied.ΠΠ·Π²Π΅ΡΡΠ½ΠΎ, ΡΡΠΎ ΠΊΠ°ΠΊ ΠΏΡΠΈΡΠΎΠ΄Π½ΡΠ΅ ΠΊΡΠ°Π½ΡΠΈΠ½Ρ, ΡΠ°ΠΊ ΠΈ ΠΈΡ
ΡΠΈΠ½ΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ Π°Π½Π°Π»ΠΎΠ³ΠΈ ΠΎΠ±Π»Π°Π΄Π°ΡΡ Π΄ΠΈΡΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠΈΠΌ Π΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ΠΌ. ΠΠ½Π°Π»ΠΈΠ· Π΄Π°Π½Π½ΡΡ
Π»ΠΈΡΠ΅ΡΠ°ΡΡΡΡ ΡΠ²ΠΈΠ΄Π΅ΡΠ΅Π»ΡΡΡΠ²ΡΠ΅Ρ ΠΎ Π·Π½Π°ΡΠΈΡΠ΅Π»ΡΠ½ΠΎΠΉ ΠΏΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²Π΅ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΡ ΡΠΈΠ½ΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΡΡ
N-ΠΌΠ΅ΡΠΈΠ»ΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
ΠΊΡΠ°Π½ΡΠΈΠ½ΠΎΠ² Π² ΠΊΠ°ΡΠ΅ΡΡΠ²Π΅ ΠΏΠΎΡΠ΅Π½ΡΠΈΠ°Π»ΡΠ½ΡΡ
Π΄ΠΈΡΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΡΠ΅Π΄ΡΡΠ². Π¦Π΅Π»Ρ Π΄Π°Π½Π½ΠΎΠΉ ΡΠ°Π±ΠΎΡΡ β ΡΠ°Π·ΡΠ°Π±ΠΎΡΠΊΠ° ΠΏΡΠ΅ΠΏΠ°ΡΠ°ΡΠΈΠ²Π½ΡΡ
ΠΌΠ΅ΡΠΎΠ΄ΠΎΠ² ΡΠΈΠ½ΡΠ΅Π·Π° 8-Π°ΠΌΠΈΠ½ΠΎΠ·Π°ΠΌΠ΅ΡΠ΅Π½Π½ΡΡ
7-(2-Π³ΠΈΠ΄ΡΠΎΠΊΡΠΈ-3-ΠΏ-ΠΌΠ΅ΡΠΎΠΊΡΠΈΡΠ΅Π½ΠΎΠΊΡΠΈΠΏΡΠΎΠΏΠΈΠ»-1)-3-ΠΌΠ΅ΡΠΈΠ»ΠΊΡΠ°Π½ΡΠΈΠ½Π° ΠΈ ΠΈΠ·ΡΡΠ΅Π½ΠΈΠ΅ ΠΈΡ
ΡΠΈΠ·ΠΈΠΊΠΎ-Ρ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΈ Π±ΠΈΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ²ΠΎΠΉΡΡΠ². Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ ΠΈ ΠΈΡ
ΠΎΠ±ΡΡΠΆΠ΄Π΅Π½ΠΈΠ΅. Π‘ΠΈΠ½ΡΠ΅Π·ΠΈΡΠΎΠ²Π°Π½ ΡΡΠ΄ 8-Π°ΠΌΠΈΠ½ΠΎΠ·Π°ΠΌΠ΅ΡΠ΅Π½Π½ΡΡ
7-(2-Π³ΠΈΠ΄ΡΠΎΠΊΡΠΈ-3-ΠΏ-ΠΌΠ΅ΡΠΎΠΊΡΠΈΡΠ΅Π½ΠΎΠΊΡΠΈΠΏΡΠΎΠΏΠΈΠ»-1)-3-ΠΌΠ΅ΡΠΈΠ»ΠΊΡΠ°Π½ΡΠΈΠ½Π°. ΠΠΎ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠ°ΠΌ Π±ΠΈΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΈΡΠΏΡΡΠ°Π½ΠΈΠΉ ΡΠΈΠ½ΡΠ΅Π·ΠΈΡΠΎΠ²Π°Π½Π½ΡΠ΅ ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΡ ΠΎΡΠ½ΠΎΡΡΡΡΡ ΠΊ IV ΠΊΠ»Π°ΡΡΡ ΡΠΎΠΊΡΠΈΡΠ½ΠΎΡΡΠΈ. 7-(2-ΠΠΈΠ΄ΡΠΎΠΊΡΠΈ-3-ΠΏ-ΠΌΠ΅ΡΠΎΠΊΡΠΈΡΠ΅Π½ΠΎΠΊΡΠΈΠΏΡΠΎΠΏΠΈΠ»-1)-8-(ΡΡΡΠΈΠ»-2-ΠΌΠ΅ΡΠΈΠ»Π°ΠΌΠΈΠ½ΠΎ)-3-ΠΌΠ΅ΡΠΈΠ»ΠΊΡΠ°Π½ΡΠΈΠ½ ΠΈΠΌΠ΅Π΅Ρ Π½Π°ΠΈΠ±ΠΎΠ»ΡΡΡΡ Π΄ΠΈΡΡΠ΅ΡΠΈΡΠ΅ΡΠΊΡΡ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ, Π° ΡΠ»Π΅Π΄ΠΎΠ²Π°ΡΠ΅Π»ΡΠ½ΠΎ Π½Π΅ΠΎΠ±Ρ
ΠΎΠ΄ΠΈΠΌΠΎ Π΄ΠΎΡΠΊΠΎΠ½Π°Π»ΡΠ½ΠΎΠ΅ ΠΈΠ·ΡΡΠ΅Π½ΠΈΠ΅, ΠΏΠΎΡΠΊΠΎΠ»ΡΠΊΡ ΠΎΠ½ Π±ΠΎΠ»Π΅Π΅ ΡΠ΅ΠΌ Π² 2 ΡΠ°Π·Π° Π°ΠΊΡΠΈΠ²Π½Π΅Π΅Β Π³ΠΈΠ΄ΡΠΎΡ
Π»ΠΎΡΡΠΈΠ°Π·ΠΈΠ΄Π°. ΠΠ΅ΠΎΠ±Ρ
ΠΎΠ΄ΠΈΠΌΠΎ ΠΏΠΎΠ΄ΡΠ΅ΡΠΊΠ½ΡΡΡ, ΡΡΠΎ Π²ΡΠ΅ ΡΠΈΠ½ΡΠ΅Π·ΠΈΡΠΎΠ²Π°Π½Π½ΡΠ΅ ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΡ ΠΎΠΊΠ°Π·ΡΠ²Π°ΡΡ Π²ΡΡΠ°ΠΆΠ΅Π½Π½ΠΎΠ΅ Π΄ΠΈΡΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠΎΠ΅ Π΄Π΅ΠΉΡΡΠ²ΠΈΠ΅. ΠΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½Π°Ρ ΡΠ°ΡΡΡ. 8-ΠΡΠΎΠΌ-7-(2-Π³ΠΈΠ΄ΡΠΎΠΊΡΠΈ-3-ΠΏ-ΠΌΠ΅ΡΠΎΠΊΡΠΈΡΠ΅Π½ΠΎΠΊΡΠΈΒΠΏΡΠΎΠΏΠΈΠ»-1)-3-ΠΌΠ΅ΡΠΈΠ»ΠΊΡΠ°Π½ΡΠΈΠ½ ΠΏΠΎΠ»ΡΡΠ΅Π½ Π½Π°Π³ΡΠ΅Π²Π°Π½ΠΈΠ΅ΠΌ 8-Π±ΡΠΎΠΌ-3-ΠΌΠ΅ΡΠΈΠ»ΠΊΡΠ°Π½ΡΠΈΠ½Π° Ρ ΠΏ-ΠΌΠ΅ΡΠΎΠΊΡΠΈΡΠ΅Π½ΠΎΠΊΡΠΈΠΌΠ΅ΡΠΈΠ»ΠΎΠΊΡΠΈΡΠ°Π½ΠΎΠΌ Π² Π±ΡΡΠ°Π½ΠΎΠ»Π΅-1 Π² ΠΏΡΠΈΡΡΡΡΡΠ²ΠΈΠΈ N,N-Π΄ΠΈΠΌΠ΅ΡΠΈΠ»Π±Π΅Π½Π·ΠΈΠ»Π°ΠΌΠΈΠ½Π°. 8-ΠΠΌΠΈΠ½ΠΎΠ·Π°ΠΌΠ΅ΡΠ΅Π½Π½ΡΠ΅ 7-(2-Π³ΠΈΠ΄ΡΠΎΠΊΡΠΈ-3-ΠΏ-ΠΌΠ΅ΡΠΎΠΊΡΠΈΒΡΠ΅Π½ΠΎΠΊΡΠΈΠΏΡΠΎΠΏΠΈΠ»-1)-3-ΠΌΠ΅ΡΠΈΠ»ΠΊΡΠ°Π½ΡΠΈΠ½Π° ΡΠΈΠ½ΡΠ΅Π·ΠΈΡΠΎΠ²Π°Π½Ρ ΠΏΡΡΠ΅ΠΌ ΠΊΠΈΠΏΡΡΠ΅Π½ΠΈΡ Π±ΡΠΎΠΌΠΎΡΠΏΠΈΡΡΠ° Ρ ΠΏΠ΅ΡΠ²ΠΈΡΠ½ΡΠΌΠΈ ΠΈ Π²ΡΠΎΡΠΈΡΠ½ΡΠΌΠΈ Π°ΠΌΠΈΠ½Π°ΠΌΠΈ. Π‘ΡΡΡΠΊΡΡΡΠ° ΡΠΈΠ½ΡΠ΅Π·ΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΠΉ ΠΎΠ΄Π½ΠΎΠ·Π½Π°ΡΠ½ΠΎ Π΄ΠΎΠΊΠ°Π·Π°Π½Π° ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΠΠ -ΡΠΏΠ΅ΠΊΡΡΠΎΡΠΊΠΎΠΏΠΈΠΈ. ΠΡΡΡΠ°Ρ ΡΠΎΠΊΡΠΈΡΠ½ΠΎΡΡΡ ΡΠΈΠ½ΡΠ΅Π·ΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΠΉ ΠΈΠ·ΡΡΠ°Π»Π°ΡΡ ΠΏΠΎ ΠΌΠ΅ΡΠΎΠ΄Ρ ΠΠ΅ΡΠ±Π΅ΡΠ°. ΠΠ·ΡΡΠ΅Π½ΠΈΠ΅ Π΄ΠΈΡΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠΎΠΉ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΡ
ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΠΉ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠ»ΠΈ ΠΏΠΎ ΠΌΠ΅ΡΠΎΠ΄Ρ ΠΠ΅ΡΡ
ΠΈΠ½Π° Π. Π. Π ΠΊΠ°ΡΠ΅ΡΡΠ²Π΅ ΡΡΠ°Π»ΠΎΠ½Π° ΡΡΠ°Π²Π½Π΅Π½ΠΈΡ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π»ΠΈ Π³ΠΈΠ΄ΡΠΎΡ
Π»ΠΎΡΡΠΈΠ°Π·ΠΈΠ΄. ΠΡΠ²ΠΎΠ΄Ρ. Π Π°Π·ΡΠ°Π±ΠΎΡΠ°Π½Ρ ΠΏΡΠΎΡΡΡΠ΅ Π² Π²ΡΠΏΠΎΠ»Π½Π΅Π½ΠΈΠΈ ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠΈ ΡΠΈΠ½ΡΠ΅Π·Π° 8-Π°ΠΌΠΈΠ½ΠΎΠ·Π°ΠΌΠ΅ΡΠ΅Π½Π½ΡΡ
7-(2-Π³ΠΈΠ΄ΡΠΎΠΊΡΠΈ-3-ΠΏ-ΠΌΠ΅ΡΠΎΠΊΡΠΈΡΠ΅Π½ΠΎΠΊΡΠΈΠΏΡΠΎΠΏΠΈΠ»-1)-3-ΠΌΠ΅ΡΠΈΠ»ΠΊΡΠ°Π½ΡΠΈΠ½Π°. Π‘ΡΡΡΠΊΡΡΡΠ° ΡΠΈΠ½ΡΠ΅Π·ΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΠΉ Π΄ΠΎΠΊΠ°Π·Π°Π½Π° ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΠΠ -ΡΠΏΠ΅ΠΊΡΡΠΎΡΠΊΠΎΠΏΠΈΠΈ. ΠΠ·ΡΡΠ΅Π½Π° ΠΎΡΡΡΠ°Ρ ΡΠΎΠΊΡΠΈΡΠ½ΠΎΡΡΡ ΠΈ Π΄ΠΈΡΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠ°Ρ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΡ
Π²Π΅ΡΠ΅ΡΡΠ².ΠΡΠ΄ΠΎΠΌΠΎ, ΡΠΎ ΡΠΊ ΠΏΡΠΈΡΠΎΠ΄Π½Ρ ΠΊΡΠ°Π½ΡΠΈΠ½ΠΈ, ΡΠ°ΠΊ Ρ ΡΡ
ΡΠΈΠ½ΡΠ΅ΡΠΈΡΠ½Ρ Π°Π½Π°Π»ΠΎΠ³ΠΈ Π²ΠΈΡΠ²Π»ΡΡΡΡ Π΄ΡΡΡΠ΅ΡΠΈΡΠ½Ρ Π΄ΡΡ. ΠΠ½Π°Π»ΡΠ· Π΄Π°Π½ΠΈΡ
Π»ΡΡΠ΅ΡΠ°ΡΡΡΠΈ ΡΠ²ΡΠ΄ΡΠΈΡΡ ΠΏΡΠΎ Π·Π½Π°ΡΠ½Ρ ΠΏΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²Ρ Π²ΠΈΠΊΠΎΡΠΈΡΡΠ°Π½Π½Ρ ΡΠΈΠ½ΡΠ΅ΡΠΈΡΠ½ΠΈΡ
ΠΏΠΎΡ
ΡΠ΄Π½ΠΈΡ
N-ΠΌΠ΅ΡΠΈΠ»ΡΠΎΠ²Π°Π½ΠΈΡ
ΠΊΡΠ°Π½ΡΠΈΠ½ΡΠ² Π² ΡΠΊΠΎΡΡΡ ΠΏΠΎΡΠ΅Π½ΡΡΠΉΠ½ΠΈΡ
Π΄ΡΡΡΠ΅ΡΠΈΡΠ½ΠΈΡ
Π·Π°ΡΠΎΠ±ΡΠ². ΠΠ΅ΡΠΎΡ Π΄Π°Π½ΠΎΡ ΡΠΎΠ±ΠΎΡΠΈ Ρ ΡΠΎΠ·ΡΠΎΠ±ΠΊΠ° ΠΏΡΠ΅ΠΏΠ°ΡΠ°ΡΠΈΠ²Π½ΠΈΡ
ΠΌΠ΅ΡΠΎΠ΄ΡΠ² ΡΠΈΠ½ΡΠ΅Π·Ρ 8-Π°ΠΌΡΠ½ΠΎΠ·Π°ΠΌΡΡΠ΅Π½ΠΈΡ
7-(2-Π³ΡΠ΄ΡΠΎΠΊΡΠΈ-3-ΠΏ-ΠΌΠ΅ΡΠΎΠΊΡΠΈΡΠ΅Π½ΠΎΠΊΡΠΈΠΏΡΠΎΠΏΡΠ»-1)-3-ΠΌΠ΅ΡΠΈΠ»ΠΊΡΠ°Π½ΡΠΈΠ½Ρ ΡΠ° Π²ΠΈΠ²ΡΠ΅Π½Π½Ρ ΡΡ
ΡΡΠ·ΠΈΠΊΠΎ-Ρ
ΡΠΌΡΡΠ½ΠΈΡ
ΡΠ° Π±ΡΠΎΠ»ΠΎΠ³ΡΡΠ½ΠΈΡ
Π²Π»Π°ΡΡΠΈΠ²ΠΎΡΡΠ΅ΠΉ. Π Π΅Π·ΡΠ»ΡΡΠ°ΡΠΈ ΡΠ° ΡΡ
ΠΎΠ±Π³ΠΎΠ²ΠΎΡΠ΅Π½Π½Ρ. ΠΡΠ² ΡΠΈΠ½ΡΠ΅Π·ΠΎΠ²Π°Π½ΠΈΠΉ ΡΡΠ΄ 8-Π°ΠΌΡΠ½ΠΎΠ·Π°ΠΌΡΡΠ΅Π½ΠΈΡ
7-(2-Π³ΡΠ΄ΡΠΎΠΊΡΠΈ-3-ΠΏ-ΠΌΠ΅ΡΠΎΠΊΡΠΈΡΠ΅Π½ΠΎΠΊΡΠΈΠΏΡΠΎΠΏΡΠ»-1)-3-ΠΌΠ΅ΡΠΈΠ»ΠΊΡΠ°Π½ΡΠΈΠ½Ρ. ΠΠ° ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠ°ΠΌΠΈ Π±ΡΠΎΠ»ΠΎΠ³ΡΡΠ½ΠΈΡ
Π²ΠΈΠΏΡΠΎΠ±ΡΠ²Π°Π½Ρ ΡΠΈΠ½ΡΠ΅Π·ΠΎΠ²Π°Π½Ρ ΡΠΏΠΎΠ»ΡΠΊΠΈ Π²ΡΠ΄Π½ΠΎΡΡΡΡΡΡ Π΄ΠΎ IV ΠΊΠ»Π°ΡΡ ΡΠΎΠΊΡΠΈΡΠ½ΠΎΡΡΡ. 7-(2-ΠΡΠ΄ΡΠΎΠΊΡΠΈ-3-ΠΏ-ΠΌΠ΅ΡΠΎΠΊΡΠΈΡΠ΅Π½ΠΎΠΊΡΠΈΠΏΡΠΎΠΏΡΠ»-1)-8-(ΡΡΡΠΈΠ»-2-ΠΌΠ΅ΡΠΈΠ»Π°ΠΌΡΠ½ΠΎ)-3-ΠΌΠ΅ΡΠΈΠ»ΠΊΡΠ°Π½ΡΠΈΠ½ Π²ΠΈΡΠ²Π»ΡΡ Π½Π°ΠΉΠ²ΠΈΡΡ Π΄ΡΡΡΠ΅ΡΠΈΡΠ½Ρ Π°ΠΊΡΠΈΠ²Π½ΡΡΡΡ, Π° ΠΎΡΠΆΠ΅ ΠΏΠΎΡΡΠ΅Π±ΡΡ Π±ΡΠ»ΡΡ Π΄ΠΎΡΠΊΠΎΠ½Π°Π»ΠΎΠ³ΠΎ Π²ΠΈΠ²ΡΠ΅Π½Π½Ρ, ΠΎΡΠΊΡΠ»ΡΠΊΠΈ Π²ΡΠ½ Π±ΡΠ»ΡΡ Π½ΡΠΆ Ρ 2 ΡΠ°Π·ΠΈ Π°ΠΊΡΠΈΠ²Π½ΡΡΠΈΠΉ Π·Π° Π³ΡΠ΄ΡΠΎΡ
Π»ΠΎΡΡΡΠ°Π·ΠΈΠ΄. ΠΠ΅ΠΎΠ±Ρ
ΡΠ΄Π½ΠΎ ΠΏΡΠ΄ΠΊΡΠ΅ΡΠ»ΠΈΡΠΈ, ΡΠΎ Π²ΡΡ ΡΠΈΠ½ΡΠ΅Π·ΠΎΠ²Π°Π½Ρ ΡΠΏΠΎΠ»ΡΠΊΠΈ Π²ΠΈΡΠ²Π»ΡΡΡΡ Π²ΠΈΡΠ°Π·Π½Ρ Π΄ΡΡΡΠ΅ΡΠΈΡΠ½Ρ Π΄ΡΡ.ΠΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½Π° ΡΠ°ΡΡΠΈΠ½Π°. 8-ΠΡΠΎΠΌΠΎ-7-(2-Π³ΡΠ΄ΡΠΎΠΊΡΠΈ-3-ΠΏ-ΠΌΠ΅ΡΠΎΠΊΡΠΈΡΠ΅Π½ΠΎΠΊΡΠΈΠΏΡΠΎΠΏΡΠ»-1)-3-ΠΌΠ΅ΡΠΈΠ»ΠΊΡΠ°Π½ΡΠΈΠ½ ΠΎΡΡΠΈΠΌΠ°Π»ΠΈ Π½Π°Π³ΡΡΠ²Π°Π½Π½ΡΠΌ 8-Π±ΡΠΎΠΌΠΎ-3-ΠΌΠ΅ΡΠΈΠ»ΠΊΡΠ°Π½ΡΠΈΠ½Ρ Π· ΠΏ-ΠΌΠ΅ΡΠΎΠΊΡΠΈΡΠ΅Π½ΠΎΠΊΡΠΈΠΌΠ΅ΡΠΈΠ»ΠΎΠΊΡΠΈΡΠ°Π½ΠΎΠΌ Ρ Π±ΡΡΠ°Π½ΠΎΠ»Ρ-1 Π² ΠΏΡΠΈΡΡΡΠ½ΠΎΡΡΡ N,N-Π΄ΠΈΠΌΠ΅ΡΠΈΠ»Π±Π΅Π½Π·ΠΈΠ»Π°ΠΌΡΠ½Ρ. 8-ΠΠΌΡΠ½ΠΎΠ·Π°ΠΌΡΡΠ΅Π½Ρ 7-(2-Π³ΡΠ΄ΡΠΎΠΊΡΠΈ-3-ΠΏ-ΠΌΠ΅ΡΠΎΠΊΡΠΈΡΠ΅Π½ΠΎΠΊΡΠΈΠΏΡΠΎΠΏΡΠ»-1)-3-ΠΌΠ΅ΡΠΈΠ»ΠΊΡΠ°Π½ΡΠΈΠ½Ρ ΡΠΈΠ½ΡΠ΅Π·ΠΎΠ²Π°Π½Ρ ΡΠ»ΡΡ
ΠΎΠΌ ΠΊΠΈΠΏβΡΡΡΠ½Π½Ρ Π±ΡΠΎΠΌΠΎΡΠΏΠΈΡΡΡ Π· ΠΏΠ΅ΡΠ²ΠΈΠ½Π½ΠΈΠΌΠΈ ΡΠ° Π²ΡΠΎΡΠΈΠ½Π½ΠΈΠΌΠΈ Π°ΠΌΡΠ½Π°ΠΌΠΈ. Π‘ΡΡΡΠΊΡΡΡΠ° ΡΠΈΠ½ΡΠ΅Π·ΠΎΠ²Π°Π½ΠΈΡ
ΡΠΏΠΎΠ»ΡΠΊ Π±ΡΠ»Π° ΠΎΠ΄Π½ΠΎΠ·Π½Π°ΡΠ½ΠΎ Π΄ΠΎΠ²Π΅Π΄Π΅Π½Π° ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΠΠ -ΡΠΏΠ΅ΠΊΡΡΠΎΡΠΊΠΎΠΏΡΡ. ΠΠΎΡΡΡΠ° ΡΠΎΠΊΡΠΈΡΠ½ΡΡΡΡ ΡΠΈΠ½ΡΠ΅Π·ΠΎΠ²Π°Π½ΠΈΡ
ΡΠΏΠΎΠ»ΡΠΊ Π±ΡΠ»Π° Π²ΠΈΠ²ΡΠ΅Π½Π° Π·Π° ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΠ΅ΡΠ±Π΅ΡΠ°. ΠΠΈΠ²ΡΠ΅Π½Π½Ρ Π΄ΡΡΡΠ΅ΡΠΈΡΠ½ΠΎΡ Π΄ΡΡ ΠΎΡΡΠΈΠΌΠ°Π½ΠΈΡ
ΡΠΏΠΎΠ»ΡΠΊ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠ»ΠΈ Π·Π° ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΠ΅ΡΡ
ΡΠ½Π° Π. Π. Π ΡΠΊΠΎΡΡΡ Π΅ΡΠ°Π»ΠΎΠ½Ρ ΠΏΠΎΡΡΠ²Π½ΡΠ½Π½Ρ Π²ΠΈΠΊΠΎΡΠΈΡΡΠΎΠ²ΡΠ²Π°Π»ΠΈ Π³ΡΠ΄ΡΠΎΡ
Π»ΠΎΡΡΡΠ°Π·ΠΈΠ΄. ΠΠΈΡΠ½ΠΎΠ²ΠΊΠΈ. ΠΡΠ»ΠΈ ΡΠΎΠ·ΡΠΎΠ±Π»Π΅Π½Ρ ΠΏΡΠΎΡΡΡ Ρ Π²ΠΈΠΊΠΎΠ½Π°Π½Π½Ρ ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠΈ ΡΠΈΠ½ΡΠ΅Π·Ρ 8-Π°ΠΌΡΠ½ΠΎΠ·Π°ΠΌΡΡΠ΅Π½ΠΈΡ
7-(2-Π³ΡΠ΄ΡΠΎΠΊΡΠΈ-3-ΠΏ-ΠΌΠ΅ΡΠΎΠΊΡΠΈΡΠ΅Π½ΠΎΠΊΡΠΈΠΏΡΠΎΠΏΡΠ»-1)-3-ΠΌΠ΅ΡΠΈΠ»ΠΊΡΠ°Π½ΡΠΈΠ½Ρ. Π‘ΡΡΡΠΊΡΡΡΠ° ΡΠΈΠ½ΡΠ΅Π·ΠΎΠ²Π°Π½ΠΈΡ
ΡΠΏΠΎΠ»ΡΠΊ Π±ΡΠ»Π° Π΄ΠΎΠ²Π΅Π΄Π΅Π½Π° ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΠΠ -ΡΠΏΠ΅ΠΊΡΡΠΎΡΠΊΠΎΠΏΡΡ. ΠΠΈΠ²ΡΠ΅Π½Π° Π³ΠΎΡΡΡΠ° ΡΠΎΠΊΡΠΈΡΠ½ΡΡΡΡ ΡΠ° Π΄ΡΡΡΠ΅ΡΠΈΡΠ½Π° Π°ΠΊΡΠΈΠ²Π½ΡΡΡΡ ΠΎΡΡΠΈΠΌΠ°Π½ΠΈΡ
ΡΠ΅ΡΠΎΠ²ΠΈΠ½
Resistively-shunted superconducting quantum point contacts
We have studied the Josephson dynamics of resistively-shunted ballistic
superconducting quantum point contacts at finite temperatures and arbitrary
number of conducting modes. Compared to the classical Josephson dynamics of
tunnel junctions, dynamics of quantum point contacts exhibits several new
features associated with temporal fluctuations of the Josephson potential
caused by fluctuations in the occupation of the current-carrying Andreev
levels.Comment: 5 pages, RevTex, 3 postscript figures include
q-Breathers and thermalization in acoustic chains with arbitrary nonlinearity index
Nonlinearity shapes lattice dynamics affecting vibrational spectrum,
transport and thermalization phenomena. Beside breathers and solitons one finds
the third fundamental class of nonlinear modes -- -breathers -- periodic
orbits in nonlinear lattices, exponentially localized in the reciprocal mode
space. To date, the studies of -breathers have been confined to the cubic
and quartic nonlinearity in the interaction potential. In this paper we study
the case of arbitrary nonlinearity index in an acoustic chain. We
uncover qualitative difference in the scaling of delocalization and stability
thresholds of -breathers with the system size: there exists a critical index
, below which both thresholds (in nonlinearity strength) tend to
zero, and diverge when above. We also demonstrate that this critical index
value is decisive for the presence or absense of thermalization. For a generic
interaction potential the mode space localized dynamics is determined only by
the three lowest order nonlinear terms in the power series expansion.Comment: 5 pages, 4 figure
On Effect of Equilibrium Fluctuations on Superfluid Density in Layered Superconductors
We calculate suppression of inter- and intralayer superconducting currents
due to equilibrium phase fluctuations and find that, in contrast to a recent
prediction, the effect of thermal fluctuations cannot account for linear
temperature dependence of the superfluid density in high-Tc superconductors at
low temperatures. Quantum fluctuations are found to dominate over thermal
fluctuations at low temperatures due to hardening of their spectrum caused by
the Josephson plasma resonance. Near Tc sizeable thermal fluctuations are found
to suppress the critical current in the stack direction stronger, than in the
direction along the layers. Fluctuations of quasiparticle branch imbalance make
the spectral density of voltage fluctuations at small frequencies non zero, in
contrast to what may be expected from a naive interpretation of Nyquist
formula.Comment: 5 pages, LaTeX, RevTeX, Submitted to PR
Study of isobar electroproduction at VEPP-2M collider
Results from the Spherical Nonmagnetic Detector (SND) on
isobar electroproduction in the collisions of beam electrons (positrons) and
residual gas nuclei in the VEPP-2M collider are presented. On the
basis of the obtained data the expected counting rate of this process in future
high luminosity colliders (~-, -- and -factories)
was estimated.Comment: 7 pages LATEX and 3 figure
Evidence of phi --> pi0 pi0 gamma and phi --> pi0 eta gamma decays in SND experiment at VEPP-2M
Preliminary results on the study of e+e- --> phi(1020) --> pi0 pi0 gamma, eta
pi0 gamma processes from SND experiment at VEPP-2M collider in Novosibirsk are
presented. Branching ratios of rare radiative phi --> pi0 pi0 gamma and phi -->
pi0 eta gamma decays are measured:
B(phi --> pi0 pi0 gamma ) = (1.1 +- 0.2) * 10^-4
(invariant mass (pi0 pi0) < 800 MeV),
B(phi --> eta pi0 gamma ) = (1.3 +- 0.5) * 10^-4.Comment: Talk at the HADRON97 conference, BNL, Aug 24-30 1997; LaTeX, 4 pages,
4 eps figure
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