301 research outputs found
Lithogenesis role in formation of zones with improved reservoir properties of subsalt carbonate sediments of venda and lower cambrian (Eastern Siberia)
The object of research is pre-salt deposits of carbonate complexes from Vendian and Lower Cambrian Nepa-Botuobiya anteclise (NBA), located in the central part of the Siberian platform, administratively dedicated to the Irkutsk region.
The problems of fluid dynamics within the basement ledges are considered. Their role in the high productivity of overlying carbonate deposits is assessed. Reconstruction of sedimentation conditions and subsequent diagenesis and katagenesis of Nepa formation sediments is made that have the greatest impact on morphostructure of the sedimentary cover. Cuts of Vendian-Cambrian sediments before and after diagenesis and katagenesis are given. Detailed construction helped to establish antiform structure of the sedimentary cover deposition over the basement ledges, allowing visually see in retrospect a sediment`s restructuring and its influence on the formation of hydrocarbon traps. The information on the rising pore pressure within the ledges is provided, due to which there is a subvertical fluid migration through both sulfate-carbonate rocks and interformational mudstones which to the beginning of elysion processes in Nepa formation were also unlithified porous sediments. It is suggested that the most permeable zones in the sulfate-carbonate rocks were formed over the edge portions of the projections as the most deformed during compaction of sand and clay deposits Nepa formation and restructuring of the upper section of the sedimentary cover. It is suggested that the elysion stage of sedimentary basin development within ledges and arched structure of Vendian-Cambrian deposits leads to dissolution and mobilization by aqueous solutions of the sedimentary rocks substance at depth and their migration mostly up. The results outlined in this paper are supported by the core data analysis
Optical detection of a single rare-earth ion in a crystal
Rare-earth-doped laser materials show strong prospects for quantum information storage and processing, as well as for biological imaging, due to their high-Q 4f↔4f optical transitions. However, the inability to optically detect single rare-earth dopants has prevented these materials from reaching their full potential. Here we detect a single photostable Pr(3+) ion in yttrium aluminium garnet nanocrystals with high contrast photon antibunching by using optical upconversion of the excited state population of the 4f↔4f optical transition into ultraviolet fluorescence. We also demonstrate on-demand creation of Pr(3+) ions in a bulk yttrium aluminium garnet crystal by patterned ion implantation. Finally, we show generation of local nanophotonic structures and cell death due to photochemical effects caused by upconverted ultraviolet fluorescence of praseodymium-doped yttrium aluminium garnet in the surrounding environment. Our study demonstrates versatile use of rare-earth atomic-size ultraviolet emitters for nanoengineering and biotechnological applications
Quantum Statistics of Surface Plasmon Polaritons in Metallic Stripe Waveguides
Single surface plasmon polaritons are excited using photons generated via
spontaneous parametric down-conversion. The mean excitation rates, intensity
correlations and Fock state populations are studied. The observed dependence of
the second order coherence in our experiment is consistent with a linear
uncorrelated Markovian environment in the quantum regime. Our results provide
important information about the effect of loss for assessing the potential of
plasmonic waveguides for future nanophotonic circuitry in the quantum regime.Comment: 21 pages, 6 figures, published in Nano Letters, publication date
(web): March 27 (2012
Radiation hydrodynamics of SN 1987A: I. Global analysis of the light curve for the first 4 months
The optical/UV light curves of SN 1987A are analyzed with the multi-energy
group radiation hydrodynamics code STELLA. The calculated monochromatic and
bolometric light curves are compared with observations shortly after shock
breakout, during the early plateau, through the broad second maximum, and
during the earliest phase of the radioactive tail. We have concentrated on a
progenitor model calculated by Nomoto & Hashimoto and Saio, Nomoto, & Kato,
which assumes that 14 solar masses of the stellar mass is ejected. Using this
model, we have updated constraints on the explosion energy and the extent of
mixing in the ejecta. In particular, we determine the most likely range of E/M
(explosion energy over ejecta mass) and R_0 (radius of the progenitor). In
general, our best models have energies in the range E = (1.1 +/- 0.3) x 10^{51}
ergs, and the agreement is better than in earlier, flux-limited diffusion
calculations for the same explosion energy. Our modeled B and V fluxes compare
well with observations, while the flux in U undershoots after about 10 days by
a factor of a few, presumably due to NLTE and line transfer effects. We also
compare our results with IUE observations, and a very good quantitative
agreement is found for the first days, and for one IUE band (2500-3000 A) as
long as for 3 months. We point out that the V flux estimated by McNaught &
Zoltowski should probably be revised to a lower value.Comment: 27 pages AASTeX v.4.0 + 35 postscript figures. ApJ, accepte
Enhanced reaction kinetics in biological cells
The cell cytoskeleton is a striking example of "active" medium driven
out-of-equilibrium by ATP hydrolysis. Such activity has been shown recently to
have a spectacular impact on the mechanical and rheological properties of the
cellular medium, as well as on its transport properties : a generic tracer
particle freely diffuses as in a standard equilibrium medium, but also
intermittently binds with random interaction times to motor proteins, which
perform active ballistic excursions along cytoskeletal filaments. Here, we
propose for the first time an analytical model of transport limited reactions
in active media, and show quantitatively how active transport can enhance
reactivity for large enough tracers like vesicles. We derive analytically the
average interaction time with motor proteins which optimizes the reaction rate,
and reveal remarkable universal features of the optimal configuration. We
discuss why active transport may be beneficial in various biological examples:
cell cytoskeleton, membranes and lamellipodia, and tubular structures like
axons.Comment: 10 pages, 2 figure
Resonant enhancement of the zero-phonon emission from a color center in a diamond cavity
We demonstrate coupling of the zero-phonon line of individual
nitrogen-vacancy centers and the modes of microring resonators fabricated in
single-crystal diamond. A zero-phonon line enhancement exceeding ten-fold is
estimated from lifetime measurements at cryogenic temperatures. The devices are
fabricated using standard semiconductor techniques and off-the-shelf materials,
thus enabling integrated diamond photonics.Comment: 5 pages, 4 figure
СООТНОШЕНИЕ РАЗЛОМНЫХ АНСАМБЛЕЙ ПАЛЕОЗОЙСКОГО И КАЙНОЗОЙСКОГО ВОЗРАСТА НА ТЕРРИТОРИИ ЗАПАДНОЙ ЧАСТИ АЛТАЕ-САЯНСКОЙ СКЛАДЧАТОЙ ОБЛАСТИ
Fault structures in folded areas are an important element of the geological structure. Their age and history of development affect seismicity, distribution of minerals, and engineering and geological characteristics of the area. The geological structure of the Altai-Sayan folded area was mainly formed during the Paleozoic and transformed during the Cenozoic activation. Geoinformation methods and technologies were used to compare between the Paleozoic and Cenozoic fault networks. It is shown that the degree of reactivation of the Paleozoic faults varies greatly within the territory.Conjugate analysis of the orientation and spatial distribution of faults of different ages in the study area does not confirm that the Cenozoic fault system was formed by reactivation or inherited development of the Paleozoic fault system. These two systems arose at different compression orientations. The left-lateral strike-slip ensemble was formed under sublatitudinal compression in the Paleozoic, and the right-lateral strike-slip ensemble - under submeridional compression in the Cenozoic. A significant coincidence between the directions of the main faults of different ages is due to their dominant strike along the boundaries of the accretionary complexes in the region.Разломные структуры в складчатых областях являются важным элементом геологической структуры. Их возраст и история развития влияют на сейсмичность, распределение полезных ископаемых, инженерно-геологические характеристики местности. Геологическая структура Алтае-Саянской складчатой области в основном сформировалась в палеозое, но была преобразована в ходе кайнозойской активизации. Методами геоинформационных технологий проведено сравнение палеозойской и кайнозойской сетей разломов. Показано, что степень реактивации палеозойских разломов сильно варьируется в пределах территории.Сопряженный анализ ориентировки и пространственного размещения разновозрастных разломов изучаемой территории не подтверждает представление о том, что кайнозойская система разломов формировалась путем реактивации или унаследованного развития палеозойской системы разрывных нарушений. Эти две системы возникали при разных ориентировках сжатия. В палеозое при субширотном сжатии формировался левосдвиговый ансамбль, а в кайнозое в условиях субмеридионального сжатия - правосдвиговый. Существенное совпадение направлений магистральных разломов разного возраста обусловлено их доминирующим простиранием согласно границам аккреционных комплексов региона
Multiorder coherent Raman scattering of a quantum probe field
We study the multiorder coherent Raman scattering of a quantum probe field in
a far-off-resonance medium with a prepared coherence. Under the conditions of
negligible dispersion and limited bandwidth, we derive a Bessel-function
solution for the sideband field operators. We analytically and numerically
calculate various quantum statistical characteristics of the sideband fields.
We show that the multiorder coherent Raman process can replicate the
statistical properties of a single-mode quantum probe field into a broad comb
of generated Raman sidebands. We also study the mixing and modulation of photon
statistical properties in the case of two-mode input. We show that the prepared
Raman coherence and the medium length can be used as control parameters to
switch a sideband field from one type of photon statistics to another type, or
from a non-squeezed state to a squeezed state and vice versa.Comment: 12 pages, 7 figures, to be published in Phys. Rev.
The effect of gamma irradiation on the structural properties of olivine
Gamma irradiation studies of (Mg0.905Fe0.095)2SiO4 olivine were performed using X-ray fluorescence method, X-ray diffraction, Raman and Mössbauer spectroscopy. The absorbed doses were 300, 600 and 1000 Gy. Small irradiation doses cause an increase of lattice vibrations and small deformation of both M1 and M2 octahedron. The observed effect is similar to the results expose to high temperature. However, the small deformation takes place only in unit cell of Olivine’s structure
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