342 research outputs found
Charge transport in poly(dG)-poly(dC) and poly(dA)-poly(dT) DNA polymers
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
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 ΡΡΠ°ΡΡΠ΅ Π°Π½Π°Π»ΠΈΠ·ΠΈΡΡΠ΅ΡΡΡ ΡΠΎΡΡΠΎΡΠ½ΠΈΠ΅ ΠΌΠ΅Π΄ΠΈΠ°ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΡ Π² Π ΠΎΡΡΠΈΠΈ. ΠΠ²ΡΠΎΡ Π΄Π°ΡΡ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΡ ΠΌΡΠ»ΡΡΠΈΠΌΠ΅Π΄ΠΈΠ° ΡΡΠ΅Π΄ΡΡΠ² ΠΈ Π°Π½Π°Π»ΠΈΠ·ΠΈΡΡΠ΅Ρ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡΠΈ ΠΈΡ
ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΡ Π² ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°ΡΠ΅Π»ΡΠ½ΠΎΠΌ ΠΏΡΠΎΡΠ΅ΡΡΠ΅
Pedagogical conditions of use of ICT
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 ΡΡΠ°ΡΡΠ΅ ΡΠ°ΡΡΠΌΠ°ΡΡΠΈΠ²Π°ΡΡΡΡ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡΠΈ ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΈΠ½ΡΠΎΡΠΌΠ°ΡΠΈΠΎΠ½Π½ΠΎΠΉ ΠΊΠΎΠΌΠΏΠ΅ΡΠ΅Π½ΡΠΈΠΈ Π² ΡΡΠ»ΠΎΠ²ΠΈΡΡ
ΠΈΠ½ΡΠΎΡΠΌΠ°ΡΠΈΠ·Π°ΡΠΈΠΈ ΡΠΎΡΡΠΈΠΉΡΠΊΠΎΠ³ΠΎ ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΡ. ΠΠΊΡΠ΅Π½Ρ Π΄Π΅Π»Π°Π΅ΡΡΡ Π½Π° Π½ΠΎΠ²ΠΎΠ΅ ΠΊΠ°ΡΠ΅ΡΡΠ²ΠΎ ΡΠΏΠ΅ΡΠΈΠ°Π»ΠΈΡΡ
Information technologies in training specialists in the field of contemporary art
This article discusses information technology in preparing students for contemporary artΠ Π΄Π°Π½Π½ΠΎΠΉ ΡΡΠ°ΡΡΠ΅ ΡΠ°ΡΡΠΌΠΎΡΡΠ΅Π½Ρ ΠΈΠ½ΡΠΎΡΠΌΠ°ΡΠΈΠΎΠ½Π½ΡΠ΅ ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΠΈ Π² ΠΏΠΎΠ΄Π³ΠΎΡΠΎΠ²ΠΊΠ΅ ΡΡΡΠ΄Π΅Π½ΡΠΎΠ² ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠ³ΠΎ ΠΈΡΠΊΡΡΡΡΠ²
Electromagnetic levitation system
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
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Implementation of the Semi Empirical Kinetic Soot Model within Chemistry Tabulation Framework for Efficient Emissions Predictions in Diesel Engines
Soot prediction for diesel engines is a very important aspect of internal combustion engine emissions research, especially nowadays with very strict emission norms. Computational Fluid Dynamics (CFD) is often used in this research and optimisation of CFD models in terms of a trade-off between accuracy and computational efficiency is essential. This is especially true in the industrial environment where good predictivity is necessary for engine optimisation, but computational power is limited. To investigate soot emissions for Diesel engines, in this work CFD is coupled with chemistry tabulation framework and semi-empirical soot model. The Flamelet Generated Manifold (FGM) combustion model precomputes chemistry using detailed calculations of the 0D homogeneous reactor and then stores the species mass fractions in the table, based on six look-up variables: pressure, temperature, mixture fraction, mixture fraction variance, progress variable and progress variable variance. Data is then retrieved during online CFD simulation, enabling fast execution times while keeping the accuracy of the direct chemistry calculation. In this work, the theory behind the model is discussed as well as implementation in commercial CFD code. Also, soot modelling in the framework of tabulated chemistry is investigated: mathematical model and implementation of the kinetic soot model on the tabulation side is described, and 0D simulation results are used for verification. Then, the model is validated using real-life engine geometry under different operating conditions, where better agreement with experimental measurements is achieved, compared to the standard implementation of the kinetic soot model on the CFD side
Localization Properties of Electronic States in Polaron Model of poly(dG)-poly(dC) and poly(dA)-poly(dT) DNA polymers
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
The development of an algorithm of adaptive discrete PID control for the extruder based on a microcontroller
Gilbert damping in noncollinear ferromagnets
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 NiFe 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 NiFe 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
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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