720 research outputs found
Photon assisted tunneling in pairs of silicon donors
Shallow donors in silicon are favorable candidates for the implementation of solid-state quantum computer architectures because of the promising combination of atomiclike coherence properties and scalability from the semiconductor manufacturing industry. Quantum processing schemes require (among other things) controlled information transfer for readout. Here we demonstrate controlled electron tunneling at 10 K from P to Sb impurities and vice versa with the assistance of resonant terahertz photons
Proton acceleration in analytic reconnecting current sheets
Particle acceleration provides an important signature for the magnetic collapse that accompanies a solar flare. Most particle acceleration studies, however, invoke magnetic and electric field models that are analytically convenient rather than solutions of the governing magnetohydrodynamic equations. In this paper a self-consistent magnetic reconnection solution is employed to investigate proton orbits, energy gains, and acceleration timescales for proton acceleration in solar flares. The magnetic field configuration is derived from the analytic reconnection solution of Craig and Henton. For the physically realistic case in which magnetic pressure of the current sheet is limited at small resistivities, the model contains a single free parameter that specifies the shear of the velocity field. It is shown that in the absence of losses, the field produces particle acceleration spectra characteristic of magnetic X-points. Specifically, the energy distribution approximates a power law ~ξ-3/2 nonrelativistically, but steepens slightly at the higher energies. Using realistic values of the “effective” resistivity, we obtain energies and acceleration times that fall within the range of observational data for proton acceleration in the solar corona
Tensor analyzing power Ayy in deuteron inclusive breakup at large Pt and spin structure of deuteron at short internucleonic distances
The Ayy data for deuteron inclusive breakup off hydrogen and carbon at a
deuteron momentum of 9.0 GeV/c and large Pt of emitted protons are presented.
The large values of Ayy independent of the target mass reflect the sensitivity
of the data to the deuteron spin structure. The data obtained at fixed and
plotted versus Pt clearly demonstrate the dependence of the deuteron spin
structure at short internucleonic distances on two variables. The data are
compared with the calculations using Paris, CD-Bonn and Karmanov's deuteron
wave functions.Comment: 4 pages, 2 figures, talk given at the SPIN2004 Conf., 10-16 Oct.
2004, Triest, Ital
Features of Formation and Development of Innovation Centers Generate
Russia entered the new millennium with the hope to build an updated state with a competitive economy. Today, competitive advantage is determined by either the size of the country, nor the level of reserves of natural resources, or even the power of financial capital. It is obvious that in the coming years will thrive on those States that provide the most complete manifestation of the professional skills and talents of its citizens will be able to excel in the development of new knowledge and practical achievements, transforming them into the most advanced technologies and products. For this is supposed to use market mechanisms to ensure a quick update, implementation and wide dissemination of advanced technologies, increasing production of competitive products in the world market. The basis of structural changes is the state innovation strategy and an active scientific and technical policy of firms and regions, focused on promoting the development of advanced research and technology breakthroughs. Scientific and technical progress affects the scope and structure of production has a significant impact on the entire world economy.
Keywords: Innovation, innovative development
JEL Classifications: О31, O33, P1
Retrospective Analysis of the Conceptual Model of Economic Management in Sub-regional Structures
Modern Russian model of building a system of economic management sub-localities based on the provisions of the Federal Law â„–131-FZ of 06.10.2003 “On general principles of local self-government in the Russian Federation”. Terms and conditions of formation of the system of local government in Russia since the beginning of the reform of its political system and establishment of a model of mutual relations of the state and local levels of government are associated with a rigid opposition rival power elite. On the basis of generalization of foreign practice of granting local governments a certain jurisdiction may be concluded that most of the issues at the local level, if we abstract from their purely legal understanding, are public in nature. Based on the research practice of interaction of bodies of state power and local self-government bodies authors consider it possible to state that the municipal authority has a number of features inherent in the government: a distinct institutionalized character; Time continuity, flexibility, universality; on the basis of laws and other regulations; implementation in a particular area in relation to all individuals within its entities; the possibility of using funds of legitimate violence; the establishment and collection of taxes; independent budgeting.
Keywords: region, economic management model, sub-regional structures
JEL Classifications: P5, R10, R5
Canonical Particle Acceleration in FRI Radio Galaxies
Matched resolution multi-frequency VLA observations of four radio galaxies
are used to derive the asymptotic low energy slope of the relativistic electron
distribution. Where available, low energy slopes are also determined for other
sources in the literature. They provide information on the acceleration physics
independent of radiative and other losses, which confuse measurements of the
synchrotron spectra in most radio, optical and X-ray studies. We find a narrow
range of inferred low energy electron energy slopes, n(E)=const*E^-2.1 for the
currently small sample of lower luminosity sources classified as FRI (not
classical doubles). This distribution is close to, but apparently inconsistent
with, the test particle limit of n(E)=const*E^-2.0 expected from strong
diffusive shock acceleration in the non-relativistic limit. Relativistic shocks
or those modified by the back-pressure of efficiently accelerated cosmic rays
are two alternatives to produce somewhat steeper spectra. We note for further
study the possiblity of acceleration through shocks, turbulence or shear in the
flaring/brightening regions in FRI jets as they move away from the nucleus.
Jets on pc scales and the collimated jets and hot spots of FRII (classical
double) sources would be governed by different acceleration sites and
mechanisms; they appear to show a much wider range of spectra than for FRI
sources.Comment: 16 figures, including 5 color. Accepted to Astrophysical Journa
High-field impurity magneto-optics of Si:Se
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