499 research outputs found
Nanocarbons And Quantum Dots Formation In New Hybrid Materials
We present technique of obtaining complex hybrid structures combining the multi-walled carbon nanotubes or multi-layer graphene and luminescent hydrophobic semiconductor core/shell quantum dots CdSe/ZnS. As a result, a formation of quantum dot decorated carbon nanotubes and graphene films is evidenced by 2D microluminescence and micro-Raman mapping of quantum dots and nanocarbons, respectively, where a spatial correlation between the luminescence and Raman signals is found. © 2014 SPIE.912612-02-00938; RFBR; Russian Foundation for Basic Research; 12-02-01263; RFBR; Russian Foundation for Basic ResearchKalantar-Zadeh, K., (2008) Nanotechnology-Enabled Sensors, p. 490. , K. Kalantar-zadeh, B. Fry. New York.: Springer Science & Business Media(1955) Springer Handbook of Nanotechnology, , Ed. B. Bhusha.-New York.: Springer Science & Business Media, 2010, ISBN: 978-3-642-02524-2Cattanach, K., Kulkarni, R.D., Kozlov, M., Manohar, S.K., Flexible carbon nanotube sensors for nerve agent simulants (2006) Nanotechnology, 17, pp. 4123-4128Peng, S., O'Keeffe, J., Wei, C., Cho, K., Kong, J., Chen, R., Franklin, N., Dai, H., Carbon nanotube chemical and mechanical sensors (2001) Proceedings of the 3rd International Workshop on Structural Health Monitoring, pp. 1-8. , USA, September 17-19, 2001, Stanford University, StanfordSnow, E.S., Perkins, F.K., Houser, E.H., Badescu, S.C., Reinecke, T.L., (2005) Science, 307, pp. 1942-1945. , Chemical detection with a single-walled carbon nanotube capacitorStar, A., Joshi, V., Skarupo, S., Thomas, D., Gabriel, J.-C.P., Gas sensor array based on metal-decorated carbon nanotubes (2006) J. Phys. Chem. B, 110, pp. 21014-21020Xu, Z., Gao, H., Guoxin, H., Solution-based synthesis and characterization of a silver nanoparticle-graphene hybrid film Carbon, 49 (14), pp. 4731-4738Cao, A., Liu, Z., Chu, S., Wu, M., Ye, Z., Cai, Z., Chang, Y., Liu, Y., A facile one-step method to produce graphene-cds quantum dot nanocomposites as promising optoelectronic materials (2010) Adv. Mater, 22, pp. 103-106Yang, Y.-K., He, Ch.-E., He, W.-J., Yu, L.-J., Peng, R.-G., Xie, X.-L., Wang, X.-B., Mai, Y.-W., Reduction of silver nanoparticles onto graphene oxide nanosheets with N,Ndimethylformamide and SERS activities of GO/Ag composites (2011) J Nanopart. Res, 13, pp. 5571-5581Lightcap, V., Kamat, P.V., Fortification of cdse quantum dots with graphene oxide. Excited state interactions and light energy conversion (2012) J. Am. Chem. Soc, 134, pp. 7109-7116Ghosh, A., Rao, K.V., Voggu, R., George, S.J., Non-covalent functionalization, solubilization of graphene and single-walled carbon nanotubes with aromatic donor and acceptor molecules (2010) Chemical Physics Letters, 488, pp. 198-201Kim, Y.-T., Han, J.H., Hong, B.H., Kwon, Y.-U., Electrochemical synthesis of cdse quantum-dot arrays on a graphene basal plane using mesoporous silica thin-film templates (2010) Adv. Mater, 22, pp. 515-518Konstantatos, G., Badioli, M., Gaudreau, L., Osmond, J., Bernechea, M., Arquer De Garcia, F.P., Gatti, F., Koppens, L.F.H., Hybrid graphene-quantum dot phototransistors with ultrahigh gain (2012) Nature Nanotechnology, 7, pp. 363-368Wang, Y., Yao, H.-B., Wang, X.-H., Yu, Sh.-H., One-pot facile decoration of CdSe quantum dots on graphene nanosheets: Novel graphene-CdSe nanocomposites with tunable fluorescent properties (2011) J. Mater. Chem, 21, pp. 562-566Murray, C.B., Gaschler, W., Sun, S., Doyle, H., Betley, T.A., Kagan, C.R., Colloidal synthesis of nanocrystals and nanocrystal superlattices IBM J. Res. & Dev., 45 (1), pp. 47-56Ermakov, V.A., Alaferdov, A.V., Vaz, A.R., Baranov, A.V., Moshkalev, S.A., Nonlocal laser annealing to improve thermal contacts between multi-layer graphene and metals (2013) Nanotechnology, 24 (15), p. 15530110Bogdanov, K., Fedorov, A., Osipov, V., Enoki, T., Takai, K., Hayashi, T., Ermakov, V., Moshkalev A, S., Annealing-induced structural changes of carbon onions: High-resolution transmission electron microscopy and Raman studies Baranov Carbon, , 02/201
Comparative analysis of regional communities’ life-worlds (on materials of the Krasnodar territory and Republic of Crimea)
Проведено сравнение жизненных миров региональных сообществ Краснодарского края и Республики Крым на основе вторичного анализа итогов анкетных опросов 2008–2015 гг. Выявлены сходства и различия ориентаций, соотношение национальной, региональной и этнических идентичностей в сообществах.
A comparison of life-worlds of the regional communities of the Krasnodar Territory and the Republic of Crimea is realized on the basis of secondary analysis of the results of questionnaires, 2008–2015. Revealed similarities and differences in orientations, the balance of national, regional and ethnic identities in this communities
Irreversibility of the magnetic state of Tm1 xTbxCo2 revealed by specific heat, electrical resistivity, and neutron diffraction measurements
The substitution of Tb for Tm in the Laves phase compound Tm Co2 leads to appearance of a magnetic moment on the Co atoms through the metamagnetic transition in the itinerant d -electron subsystem and gives rise to long-range ferrimagnetic order in Tm1-x Tbx Co2 at x≥0.15. The magnetic state of the compound Tm0.9 Tb0.1 Co2, i.e., just below the critical Tb concentration, is characterized by the presence of large regions with short-range magnetic order and localized spin fluctuations (LSFs) induced in the Co 3d -electron subsystem by the fluctuating f-d exchange due to the Tm-Tb substitution. The peculiar magnetic state of this compound is strongly influenced by an external magnetic field which produces a first-order magnetic phase transition to a long-range ferrimagnetic state with the magnetic moment on the Co atoms up to (0.7-0.8) μB. This field-induced transition in Tm0.9 Tb0.1 Co2 is found to be irreversible. It is accompanied by a giant and irreversible reduction of the electrical resistivity (Δρ ρ∼-45%), specific heat (by about 3.7 times at 2 K), and intensity of magnetic neutron scattering. Such behavior is associated with the field-induced metamagnetic transition in the itinerant d -electron subsystem mediated by the f-d exchange. Significantly enhanced values of the residual resistivity and the coefficient γ of the T -linear contribution to the specific heat in the compound with x=0.1 as well as their unusual behavior with temperature and under application of the magnetic field is ascribed to the presence of LSF. © 2006 The American Physical Society.This work was partly performed at the Swiss Spallation Neutron Source SINQ, Paul Scherrer Institute (PSI), Villigen, Switzerland. This work was supported by the Russian Foundation for Basic Research (Grant No. 04-02-96060) and by the Swiss National Science Foundation (SCOPES Project No. IB7420-110849)
Unintegrated gluon distributions in D* and dijet associated photoproduction at HERA
We consider the photoproduction of D* mesons associated with two hadron jets
at HERA collider in the framework of the kt-factorization approach. The
unintegrated gluon densities in a proton are obtained from the full CCFM, from
unified BFKL-DGLAP evolution equations as well as from the Kimber-Martin-Ryskin
prescription. Resolved photon contributions are reproduced by the initial-state
gluon radiation. We investigate different production rates and make comparison
with the recent experimental data taken by the ZEUS collaboration. Special
attention is put on the specific dijet correlations which can provide unique
information about non-collinear gluon evolution dynamics.Comment: 31 pages, 18 figure
The influence of the structure imperfectness of a crystalline undulator on the emission spectrum
We study the influence of an imperfect structure of a crystalline undulator
on the spectrum of the undulator radiation. The main attention is paid to the
undulators in which the periodic bending in the bulk appears as a result of a
regular (periodic) surface deformations. We demonstrate that this method of
preparation of a crystalline undulator inevitably leads to a variation of the
bending amplitude over the crystal thickness and to the presence of the
subharmonics with smaller bending period. Both of these features noticeably
influence the monochromatic pattern of the undulator radiation.Comment: 26 pages, 9 figures, IOP style, submitted to NIM
The CCFM Monte Carlo generator CASCADE 2.2.0
CASCADE is a full hadron level Monte Carlo event generator for ep, \gamma p
and p\bar{p} and pp processes, which uses the CCFM evolution equation for the
initial state cascade in a backward evolution approach supplemented with off -
shell matrix elements for the hard scattering. A detailed program description
is given, with emphasis on parameters the user wants to change and variables
which completely specify the generated events
Study of the Linked Dipole Chain Model in heavy quark production at the Tevatron
We present calculations of charm and beauty production at Tevatron within the
framework of kT-factorization, using the unintegrated gluon distributions as
obtained from the Linked Dipole Chain model. The analysis covers transverse
momentum and rapidity distributions and the azimuthal correlations between b
and bbar quarks (or rather muons from their decay) which are powerful tests for
the different unintegrated gluon distributions. We compare the theoretical
results with recent experimental data taken by D0 and CDF collaborations at the
Tevatron Run I and II.Comment: 16 page
Field-linked States of Ultracold Polar Molecules
We explore the character of a novel set of ``field-linked'' states that were
predicted in [A. V. Avdeenkov and J. L. Bohn, Phys. Rev. Lett. 90, 043006
(2003)]. These states exist at ultralow temperatures in the presence of an
electrostatic field, and their properties are strongly dependent on the field's
strength. We clarify the nature of these quasi-bound states by constructing
their wave functions and determining their approximate quantum numbers. As the
properties of field-linked states are strongly defined by anisotropic dipolar
and Stark interactions, we construct adiabatic surfaces as functions of both
the intermolecular distance and the angle that the intermolecular axis makes
with the electric field. Within an adiabatic approximation we solve the 2-D
Schrodinger equation to find bound states, whose energies correlate well with
resonance features found in fully-converged multichannel scattering
calculations
Interplay of magnetization dynamics with a microwave waveguide at cryogenic temperatures
In this work, magnetization dynamics is studied at low temperatures in a hybrid system that consists of a thin epitaxial magnetic film coupled with a superconducting planar microwave waveguide. The resonance spectrum was observed over a wide magnetic field range, including low fields below the saturation magnetization and both polarities. Analysis of the spectrum via a fitting routine we develop allows the derivation of all magnetic parameters of the film at cryogenic temperatures, the detection of waveguide-induced uniaxial magnetic anisotropies of the first and the second order, and the uncovering of a minor misalignment of the magnetic field. A substantial influence of the superconducting critical state on the resonance spectrum is observed and discussed
Photoproduction of J/psi mesons at high energies in parton model and k_t-faktorization approach
We consider J/psi meson photoproduction on protons at high energies at the
leading order in alpha_s using conventional parton model and k_t-factorization
approach of QCD. It is shown that in the both cases the colour singlet
mechanism gives correct description for experimental data from HERA for the
total cross section and for the J/psi meson z-spectrum at realistic values of a
c-quark mass and meson wave function at the origin Psi (0). At the same time
our predictions for p_t-spectrum of J/psi meson and for p_t dependence of the
spin parameter alpha obtained in k_t-factorization approach are very different
from the results obtained in conventional parton model. Such a way the
experimental study of a polarized J/psi meson production at the large p_t
should be a direct test of BFKL gluons.Comment: LaTeX2e, 11 pages plus 8 fig. using epsfig.st
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