8,869 research outputs found
Lobster Eye X-ray optics for astrophysics: Recent status
X-ray optics in Lobster Eye arrangement represent promising complementary device to narrow field X-ray optics in common use. We present briefly recent status of design, developments, and tests of X-ray optics including Lobster Eye modules developed and tested within recent space project
Hyperpolarized xenon nuclear spins detected by optical atomic magnetometry
We report the use of an atomic magnetometer based on nonlinear
magneto-optical rotation with frequency modulated light (FM NMOR) to detect
nuclear magnetization of xenon gas. The magnetization of a
spin-exchange-polarized xenon sample (cm at a pressure of bar,
natural isotopic abundance, polarization 1%), prepared remotely to the
detection apparatus, is measured with an atomic sensor (which is insensitive to
the leading field of 0.45 G applied to the sample; an independent bias field at
the sensor is G). An average magnetic field of nG induced by
the xenon sample on the 10-cm diameter atomic sensor is detected with
signal-to-noise ratio , limited by residual noise in the magnetic
environment. The possibility of using modern atomic magnetometers as detectors
of nuclear magnetic resonance and in magnetic resonance imaging is discussed.
Atomic magnetometers appear to be ideally suited for emerging low-field and
remote-detection magnetic resonance applications.Comment: 4 pages, 4 figure
Engineering study to determine feasible methods of simulating planetary albedo and radiation effects upon the thermal balance of spacecraft Final report
Planetary radiation and albedo effects on thermal balance of spacecraft orbiting Mars and Venu
Geometric phases of scattering states in a ring geometry: adiabatic pumping in mesoscopic devices
Geometric phases of scattering states in a ring geometry are studied based on
a variant of the adiabatic theorem. Three time scales, i.e., the adiabatic
period, the system time and the dwell time, associated with adiabatic
scattering in a ring geometry plays a crucial role in determining geometric
phases, in contrast to only two time scales, i.e., the adiabatic period and the
dwell time, in an open system. We derive a formula connecting the gauge
invariant geometric phases acquired by time-reversed scattering states and the
circulating (pumping) current. A numerical calculation shows that the effect of
the geometric phases is observable in a nanoscale electronic device.Comment: 9 pages, 3 figure
High Energy Gamma--Radiation from the Galactic Center due to Neutralino Annihilation
We study the NGS (Non--dissipative Gravitational Singularity) model, which
successfully describes the non--linear stage of evolution of perturbations (see
[1], [2] and references therein). This model predicts DM density distribution
with which holds from very small
distances up to very large distances . Assuming the neutralino to be a CDM particle, we
calculate the annihilation of neutralinos in the vicinity of the singularity
(Galactic Center). If neutralinos are the dominant component of DM in our
Galaxy, the produced energy is enough to provide the whole observed activity of
the GC. Neutralinos of the most general composition and of mass in the range
20~{\rm GeV} \leq m_\c \leq 1~{\rm TeV} are considered. We find the
neutralino compositions which give the relic density needed for the Mixed Dark
Matter (MDM) model and we evaluate for these compositions the high--energy
() gamma--ray flux under the constraint that the
radio flux is lower than the observational limit. The compositions with the
detectable gamma--ray flux which we found are provided by a set of almost pure
gaugino states with the neutralino mass between and GeV. We
demonstrate that a detectable high--energy gamma--ray flux is produced by the
neutralino annihilation also in the case when neutralinos provide a small
fraction (down to ) of the DM in our Galaxy. The predicted flux is
for E_\gamma \gsim
300~{\rm MeV}Comment: Plain TeX 11 pages 4 figures available on request. Preprint numbers
LNGS 94/90 - DFTT 5/9
Reconstruction of modified gravity with ghost dark energy models
In this work, we reconstruct the modified gravity for different ghost
and generalized ghost dark energy models in FRW flat universe, which describe
the accelerated expansion of the universe. The equation of state of
reconstructed - gravity has been calculated. We show that the
corresponding gravity of ghost dark energy model can behave like phantom
or quintessence. We also show that the equation of state of reconstructed
gravity for generalized ghost model can transit from quintessence regime
to the phantom regime as indicated by recent observations.Comment: 13 pages, some references and one author are added. Accepted for
publication by MPL
Суспільне значення музеїв
Урбан В. А. Суспільне значення музеїв / В. А. Урбан // Сучасні проблеми правового, економічного та соціального розвитку держави : тези доп. Міжнар. наук.-практ. конф. (м. Харків, 27 листоп. 2020 р.). – Харків, 2020. – С. 298 - 299.Розкривається суспільне значення музеїв. Людство завжди ставило перед собою питання: «а що ж було раніше?», а музеї завжди знаходили відповідь на це запитання. За своїм профілем сучасні музеї поділяються на історичні, археологічні, краєзнавчі, природничі, мистецькі, літературні. Всі вони створені для збереження і демонстрації комплексів пам’яток, які відносяться до певного типу культурно-історичних надбань людства.
Раскрывается публичное значение музеев. Человечество всегда задавало вопрос: «а что же было раньше?», а музеи всегда находили ответ на этот вопрос. По своему профилю современные музеи делятся на исторические, археологические, краеведческие, естественные, художественные, литературные. Все они созданы для сохранения и демонстрации комплексов памятников, относящихся к определенному типу культурно-исторического достояния человечества.
The social significance of museums is revealed. Mankind has always asked the question: "What happened before?", And museums have always found the answer to this question. According to their profile, modern museums are divided into historical, archaeological, local lore, natural, artistic, literary. All of them are designed to preserve and demonstrate complexes of monuments that belong to a certain type of cultural and historical heritage of mankind
A framework for community curation of interspecies interactions literature
The quantity and complexity of data being generated and published in biology has increased substantially, but few methods exist for capturing knowledge about phenotypes derived from molecular interactions between diverse groups of species, in such a way that is amenable to data-driven biology and research. To improve access to this knowledge, we have constructed a framework for the curation of the scientific literature studying interspecies interactions, using data curated for the Pathogen–Host Interactions database (PHI-base) as a case study. The framework provides a curation tool, phenotype ontology, and controlled vocabularies to curate pathogen–host interaction data, at the level of the host, pathogen, strain, gene, and genotype. The concept of a multispecies genotype, the ‘metagenotype,’ is introduced to facilitate capturing changes in the disease-causing abilities of pathogens, and host resistance or susceptibility, observed by gene alterations. We report on this framework and describe PHI-Canto, a community curation tool for use by publication authors
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