587 research outputs found
The two Josephson junction flux qubit with large tunneling amplitude
In this paper we discuss solid-state nanoelectronic realizations of Josephson
flux qubits with large tunneling amplitude between the two macroscopic states.
The latter can be controlled via the height and wells form of the potential
barrier, which is determined by quantum-state engineering of the flux qubit
circuit. The simplest circuit of the flux qubit is a superconducting loop
interrupted by a Josephson nanoscale tunnel junction. The tunneling amplitude
between two macroscopically different states can be essentially increased, by
engineering of the qubit circuit, if tunnel junction is replaced by a ScS
contact. However, only Josephson tunnel junctions are particularly suitable for
large-scale integration circuits and quantum detectors with preset-day
technology. To overcome this difficulty we consider here the flux qubit with
high-level energy separation between "ground" and "excited" states, which
consists of a superconducting loop with two low-capacitance Josephson tunnel
junctions in series. We demonstrate that for real parameters of resonant
superposition between the two macroscopic states the tunneling amplitude can
reach values greater than 1K. Analytical results for the tunneling amplitude
obtained within semiclassical approximation by instanton technique show good
correlation with a numerical solution.Comment: 8 pages, 4 figure
Degenerate Odd Poisson Bracket on Grassmann Variables
A linear degenerate odd Poisson bracket (antibracket) realized solely on
Grassmann variables is presented. It is revealed that this bracket has at once
three nilpotent -like differential operators of the first, the second
and the third orders with respect to the Grassmann derivatives. It is shown
that these -like operators together with the Grassmann-odd nilpotent
Casimir function of this bracket form a finite-dimensional Lie superalgebra.Comment: 5 pages, LATEX. Corrections of misprints. The relation (23) is adde
Purely twistorial string with canonical twistor field quantization
We introduce new purely twistorial scale-invariant action describing the
composite bosonic D=4 Nambu-Goto string with target space parametrized by the
pair of D=4 twistors. We show that by suitable gauge fixing of local scaling
one gets the bilinear twistorial action and canonical quantization rules for
the two-dimensional twistor-string fields. We consider the Poisson brackets of
all constraints characterizing our model and we obtain four first class
constraints describing two Virasoro constraints and two U(1)xU(1) Kac-Moody
(KM) local phase transformations.Comment: v3: 6p.(extended version), in press in Physical Review
Влияние научно-технического прогресса на организацию полиграфического производства
Проведено дослідження актуальних тенденцій впливу науково-технічного прогресу на організацію поліграфічного виробництва.The research is devoted to the actual scientific and technical progress influence over polygraphy organization.Проведено исследование актуальных тенденций влияния научно-технического прогресса на организацию полиграфического производства
Hodge Duality Operation And Its Physical Applications On Supermanifolds
An appropriate definition of the Hodge duality operation on any
arbitrary dimensional supermanifold has been a long-standing problem. We define
a working rule for the Hodge duality operation on the -dimensional supermanifold parametrized by a couple of even (bosonic)
spacetime variables and a couple of Grassmannian (odd)
variables and of the Grassmann algebra. The Minkowski
spacetime manifold, hidden in the supermanifold and parametrized by , is chosen to be a flat manifold on which a two -dimensional
(2D) free Abelian gauge theory, taken as a prototype field theoretical model,
is defined. We demonstrate the applications of the above definition (and its
further generalization) for the discussion of the (anti-)co-BRST symmetries
that exist for the field theoretical models of 2D- (and 4D) free Abelian gauge
theories considered on the four - (and six )-dimensional
supermanifolds, respectively.Comment: LaTeX file, 25 pages, Journal-versio
Variation of fatty acid composition in seed oil in the collection of induced oil flax (Linum humile Mill.) mutants
A wide variety of application fields for flax seeds requires for breeders to develop new varieties with different characteristics, corresponding to the intended final product. The method of experimental mutagenesis is one of the ways to solve this problem. This method allows mutant lines with an array of morphometric and biochemical traits to be created from a single species and within a relatively short period of time. The article demonstrates that treatment of Linum humile Mill. seeds of the cultivars Iceberg and Solnech-ny with the new chemical mutagens DG-2, DG-6, DG-7, DG-9 (derivatives of dimethyl sulfate (DMS)) as well as with the mutagens DMS and EMS resulted in the production of mutant lines and accessions with altered morphometric and biochemical parameters. Seeds of the initial cultivars were treated with 0.5 and 0.05 % aqueous solutions of the above mentioned substances and planted in the field to raise M1, M2, and M3 generations. Ultimately, 27 types of mutations were identified and subdivided into five groups by morphometric characteristics. The fatty acid composition of seed oil for the isolated mutant specimens was studied: the content of palmitic, stearic, oleic, linoleic (w6) and lino-lenic (w3) acids, as well as the w6/w3 ratio. The statistical analysis showed significant distinctions between the mutant lines in the biochemical composition of the oil. A strong negative correlation between the content of linoleic and linolenic acids was demonstrated, as well as a positive relationship of average strength between the content of stearic and oleic acids for the both varieties. The mutant accessions obtained can be used as donor material for conducting breeding work on flax in various directions
Математичне моделювання електропідсилювача керма транспортного засобу з черв’ячною передачею
The complexity and variety of requirements imposed on modern cars have led to a variety of designs of steering amplifiers, which are based on various physical phenomena and patterns (mechanical, pneumatic, hydraulic, electrical, etc.). Despite the difference in design and operating principles, steering amplifiers of domestic and foreign production are based on a large number of complex components and parts, which reduces their reliability. In addition, due to the constant impact of amplifiers on the controlled wheels, the driver does not feel changes in the behavior of the car on the road when disturbing influences occur, which reduces traffic safety and can lead to an accident. Therefore, increasing the sensitivity of the steering wheel to adverse factors acting on the wheels of the car while driving is one of the important tasks of improving power steering system.
Introduction of electric power steering systems for cargo and passenger vehicles with a load capacity of up to 20 tons. this is a very urgent problem. In contrast to power steering system, which is still used in the control systems of high-tonnage vehicles, electric power is much simpler in design, does not require much time and costs for operation and repair.
Electric power steering system with worm drive, which has a gear ratio significantly higher than those used in passenger cars, is considered. For this purpose, the formula for calculating the active moment of resistance due to the angle of transverse inclination of the pin and the corresponding system of differential equations characterizing the electric power steering system with worm drive are derived. Based on this, a functional diagram of the electric power steering control system has been developed, which is unified for worm drive steering systems and can serve as a base for modeling the steering system of cargo and passenger vehicles.Перераховані переваги електропідси-лювача в порівнянні з гідропідсилювачем керма. Наведено можливі компонування електропідсилювача керма. Виведена формула для розрахунку активного моменту опору, обумовленого кутом поперечного нахилу шворня. Дана система диференціальних рівнянь, що характеризують електропідсилювач керма з черв’ячною передачею. Зображена функціональна схема електро-підсилювача керма
Інноваційна діяльність у видавничій справі
The specifics of innovative activity in publishing in Ukraine are considered. The life cycle of innovative publishing activity is studied. Attention is focused on the importance of further implementation of innovative activities in publishing.Розглянуто специфіку інноваційної діяльності у видавничій справі в Україні. Досліджено життєвий цикл інноваційної видавничої діяльності. Акцентовано увагу на важливості подальшої реалізації інноваційної діяльності у видавництві
Quantum superposition of three macroscopic states and superconducting qutrit detector
Superconducting quantum coherent circuits have opened up a novel area of
fundamental low-temperature science since they could potentially be the element
base for future quantum computers. Here we report a quasi-three-level coherent
system, the so-called superconducting qutrit, which has some advantages over a
two-level information cell (qubit), and is based on the qutrit readout circuit
intended to measure individually the states of each qubit in a quantum
computer. The designed and implemented radio-frequency superconducting qutrit
detector (rf SQUTRID) with atomic-size ScS-type contact utilizes the
coherent-state superposition in the three-well potential with energy splitting
Delta E_01/k_B=1.5 K at the 30th quantized energy level with good isolation
from the electromagnetic environment. The reason why large values of Delta E_01
(and thus using atomic-size Nb-Nb contact) are required is to ensure an
adiabatic limit for the quantum dynamics of magnetic flux in the rf SQUTRID.Comment: 9 pages, 5 figures, in v.3: text extended, inset in figure 1 (the
device design) adde
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