Current-phase relation in SFS Josephson junctions in the presence of <Emphasis Type="Italic">s</Emphasis>-<Emphasis Type="Italic">d</Emphasis> scattering

The analytical equations for the current-phase relation (CPR) coefficients for Josephson junctions with a ferromagnetic interlayer in the model where the scattering from s- to d-band is considered to be the main type scattering of charge carrier in a ferromagnet are obtained. It is shown that the magnitude of the coefficients oscillates and decays with an increase of the interlayer thickness. Both the oscillation period and the decay length for the first and the second harmonics differ by two times. The temperature dependence of the critical current demonstrating 0-π temperature transitions is obtained. The possibility of design a flux qubit based on such Josephson junctions is demonstrated.     

Effect of driver over-acceleration on traffic breakdown in three-phase cellular automaton traffic flow models

Based on simulations with cellular automaton (CA) traffic flow models, a generic physical feature of the three-phase models studied in the paper is disclosed. The generic feature is a discontinuous character of driver over-acceleration caused by a combination of two qualitatively different mechanisms of over-acceleration: (i) Over-acceleration through lane changing to a faster lane, (ii) over-acceleration occurring in car-following without lane changing. Based on this generic feature a new three-phase CA traffic flow model is developed. This CA model explains the set of the fundamental empirical features of traffic breakdown in real heterogeneous traffic flow consisting of passenger vehicles and trucks. The model simulates also quantitative traffic pattern characteristics as measured in real heterogeneous flow.     

Generation of oxodiazonium ions 6. Unexpected formation of tetrazole 1-oxides

(E)-2-[2,2-Bis(tert-butyl-NNO-azoxy)-1-(methylsulfinyl)vinyl]-1-isopropoxydiazene 1-oxide reacts with boron trifluoride etherate (BF₃?Et₂O) producing 2-tert-butyl-N-nitro-2H-tetrazolo-5-carboxamide 4-oxide and 2-tert-butyl-2H-tetrazolo-5-carbonitrile 4-oxide but not the expected 1,2,3,4-tetrazine 1,3-dioxide derivative. This reaction direction can be explained by cationic domino cyclization, the key stage of which is coupling of the oxodiazonium ion with the geminal MeS(O) group. Structure of N-nitrocarboxamide was confirmed by X-ray diffraction analysis.     

Approaches to the creation of an active electrically small superconductive antenna

The physical principles of designing active electrically small superconductive antennas are investigated. These antennas are based on an array of superconducting quantum interference cells characterized by a high linearity of magnetic-signal conversion into voltage. The results of experimental investigation into an active antenna prototype containing 80 cells connected in series and occupying an area of 3.3 × 3.3 m are presented. The proposed integrated circuit is fabricated via the standard niobium technique of the formation of Josephson-junction elements with a critical current density of 4.5 kA/cm².     

Progress in high-linearity multi-element Josephson structures

This paper summarizes both theoretical and experimental studies aimed at synthesis of high-linearity multi-element Josephson structures. Both the dynamic range and the voltage response linearity are two conjugated characteristics that must be improved jointly. Increase in dynamic range is reasonably associated with increase of number of elements N in the Josephson-junction structures. To improve the voltage response linearity one can use special design of the array structures. The other way is based on use novel basic cell with is bi-SQUID capable of providing highly linear voltage response. Both the approaches were used in designs of the reported high-linearity multi-element Josephson structures.     

Distributed Center for Nuclear Medicine of the NRC “Kurchatov Institute”: Historical Background,Current Status,and Evolution Outlook

Crystallography Reports - An integral part of the modern oncology service is the high-tech equipment based on nuclear physics methods. An interdisciplinary approach to the development of nuclear...     

Detection of Terahertz,Mid- and Near Infrared Radiation by a Multilayer Metal—Insulator Heterostructure

An analogy between the tunneling of quantum particles through a chain of barriers and the propagation of electromagnetic waves through a metamedium has allowed new methods for the fabrication of selective detectors of terahertz, mid-infrared, and near infrared radiation. The calculations have shown that a resonance metal-insulator heterostructure with one and two metal layers allows achieving nearly 100% absorption of radiation in a narrow frequency range. The use of a large number of metal layers makes it possible to detect ultrashort (including picosecond) field pulses with a broad spectrum.

     

Generation of oxodiazonium ions 2. Synthesis of benzotetrazine-1,3-dioxides from 2-(tert-butyl-NNO-azoxy)-N-nitroanilines

A new method for the synthesis of benzotetrazine-1,3-dioxides was developed, which involves the reaction of 2-(tert-butyl-NNO-azoxy)-N-nitroanilines with the Ac₂O/H₂SO₄ system. This method was also used for the synthesis of [1,2,5]oxadiazolo[3,4-c]cinnoline-5-oxide from 3-nitramino-4-phenylfurazan. The suggested mechanism of these reactions involves the formation of the intermediate oxodiazonium ion, resulting from acetylation of the oxygen atom of the nitramine group, followed by protonation and ionic dissociation. Then the oxodiazonium ion enters the intramolecular reaction with the neighboring tert-butyl-NNO-azoxy or phenyl group to form the corresponding heterocyclic systems.