342 research outputs found

    Charge transport in poly(dG)-poly(dC) and poly(dA)-poly(dT) DNA polymers

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    We investigate the charge transport in synthetic DNA polymers built up from single types of base pairs. In the context of a polaron-like model, for which an electronic tight-binding system and bond vibrations of the double helix are coupled, we present estimates for the electron-vibration coupling strengths utilizing a quantum-chemical procedure. Subsequent studies concerning the mobility of polaron solutions, representing the state of a localized charge in unison with its associated helix deformation, show that the system for poly(dG)-poly(dC) and poly(dA)-poly(dT) DNA polymers, respectively possess quantitatively distinct transport properties. While the former supports unidirectionally moving electron breathers attributed to highly efficient long-range conductivity the breather mobility in the latter case is comparatively restrained inhibiting charge transport. Our results are in agreement with recent experimental results demonstrating that poly(dG)-poly(dC) DNA molecules acts as a semiconducting nanowire and exhibits better conductance than poly(dA)-poly(dT) ones.Comment: 11 pages, 5 figure

    Theory and practice multimedia in education

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    The article examines the state of media education in Russia. The author gives the characteristic of the multimedia tools and analyses their applicability inthe educational process.Π’ ΡΡ‚Π°Ρ‚ΡŒΠ΅ анализируСтся состояниС мСдиаобразования Π² России. Автор даѐт характСристику ΠΌΡƒΠ»ΡŒΡ‚ΠΈΠΌΠ΅Π΄ΠΈΠ° срСдств ΠΈ Π°Π½Π°Π»ΠΈΠ·ΠΈΡ€ΡƒΠ΅Ρ‚ возмоТности ΠΈΡ… примСнСния Π² ΠΎΠ±Ρ€Π°Π·ΠΎΠ²Π°Ρ‚Π΅Π»ΡŒΠ½ΠΎΠΌ процСссС

    Pedagogical conditions of use of ICT

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    The article discusses the formation of information competence in the conditions of informatization of Russian education. The focus is on a demand-driven quality specialistΠ’ ΡΡ‚Π°Ρ‚ΡŒΠ΅ Ρ€Π°ΡΡΠΌΠ°Ρ‚Ρ€ΠΈΠ²Π°ΡŽΡ‚ΡΡ возмоТности формирования ΠΈΠ½Ρ„ΠΎΡ€ΠΌΠ°Ρ†ΠΈΠΎΠ½Π½ΠΎΠΉ ΠΊΠΎΠΌΠΏΠ΅Ρ‚Π΅Π½Ρ†ΠΈΠΈ Π² условиях ΠΈΠ½Ρ„ΠΎΡ€ΠΌΠ°Ρ‚ΠΈΠ·Π°Ρ†ΠΈΠΈ российского образования. АкцСнт дСлаСтся Π½Π° Π½ΠΎΠ²ΠΎΠ΅ качСство спСциалист

    Information technologies in training specialists in the field of contemporary art

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    This article discusses information technology in preparing students for contemporary artΠ’ Π΄Π°Π½Π½ΠΎΠΉ ΡΡ‚Π°Ρ‚ΡŒΠ΅ рассмотрСны ΠΈΠ½Ρ„ΠΎΡ€ΠΌΠ°Ρ†ΠΈΠΎΠ½Π½Ρ‹Π΅ Ρ‚Π΅Ρ…Π½ΠΎΠ»ΠΎΠ³ΠΈΠΈ Π² ΠΏΠΎΠ΄Π³ΠΎΡ‚ΠΎΠ²ΠΊΠ΅ студСнтов соврСмСнного искусств

    Electromagnetic levitation system

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    Magnetism is a physical phenomenon produced by the motion of electric charge, resulting in attractive and repulsive forces between objects. It is widely adopted in many spheres of our routine life. By using the effect of magnetism, it has become possible to create non-frictional bearings, contact-free shock absorbers and many things, which found their appliance in industrial usage. There are many great inventions connected with magnets, such as the train on the air cushion (Maglev train). Maglev stands for magnetic levitation, a principle that allows keeping an object in midair. This technology has a great potential, however there are always things, which need to be improved, for instance reduction of disturbance and lowering of the price

    Localization Properties of Electronic States in Polaron Model of poly(dG)-poly(dC) and poly(dA)-poly(dT) DNA polymers

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    We numerically investigate localization properties of electronic states in a static model of poly(dG)-poly(dC) and poly(dA)-poly(dT) DNA polymers with realistic parameters obtained by quantum-chemical calculation. The randomness in the on-site energies caused by the electron-phonon coupling are completely correlated to the off-diagonal parts. In the single electron model, the effect of the hydrogen-bond stretchings, the twist angles between the base pairs and the finite system size effects on the energy dependence of the localization length and on the Lyapunov exponent are given. The localization length is reduced by the influence of the fluctuations in the hydrogen bond stretchings. It is also shown that the helical twist angle affects the localization length in the poly(dG)-poly(dC) DNA polymer more strongly than in the poly(dA)-poly(dT) one. Furthermore, we show resonance structures in the energy dependence of the localization length when the system size is relatively small.Comment: 6 pages, 6 figure

    Gilbert damping in noncollinear ferromagnets

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    The precession and damping of a collinear magnetization displaced from its equilibrium are described by the Landau-Lifshitz-Gilbert equation. For a noncollinear magnetization, it is not known how the damping should be described. We use first-principles scattering theory to investigate the damping in one-dimensional transverse domain walls (DWs) of the important ferromagnetic alloy Ni80_{80}Fe20_{20} and interpret the results in terms of phenomenological models. The damping is found to depend not only on the magnetization texture but also on the specific dynamic modes of Bloch and N\'eel DWs. Even in the highly disordered Ni80_{80}Fe20_{20} alloy, the damping is found to be remarkably nonlocal.Comment: Final version accepted by Physical Review Letter

    The pipeline oil pumping engineering based on the Plant Wide Control technology

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    This article provides recommendations for the use technology Plant Wide Control to control the pumping of oil through the pipeline. The proposed engineering using pipeline management in general (Pipe Wide Control) will reduce the loss of electric power at the expense of the balance of pumping stations located along the pipeline route
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