562 research outputs found
The low-frequency response in the surface superconducting state of ZrB single crystal}
The large nonlinear response of a single crystal ZrB to an ac field
(frequency 40 - 2500 Hz) for has been observed. Direct
measurements of the ac wave form and the exact numerical solution of the
Ginzburg-Landau equations, as well as phenomenological relaxation equation,
permit the study of the surface superconducting states dynamics. It is shown,
that the low frequency response is defined by transitions between the
metastable superconducting states under the action of an ac field. The
relaxation rate which determines such transitions dynamics, is found.Comment: 7 pages, 11 figure
Age-related hearing loss: biological aspects
Presbycusis is one of the more prevalent neurodegenerative disease of aging. There are many studies about the influence of environmental and genetic factors. Age-related hearing loss is caused by changes in peripheral (cell loss in organ of Corti, spiral ganglion and stria vascularis) and central auditory systems (consequent to peripheral modifications or for changes in the neurobiologic activity underlying central processing of auditory informations) [1]. Consequences are reduced sensitivity, tuning sharpness, compression, and reduced signal-to-noise ratios, deficits in auditory discrimination, temporal processing, processing of degraded auditory signals or when embedded in competing acoustic signals. Approaching biology of age-related hearing loss is complex: it needs to clarify some peripheral aspects with different cochlear structure and cellular type affected, and some others central auditory processing aspects. There are some peripherally induced central effects and others direct neurodegenerative changes in the brain. Moreover biochemical and mechanical injury in life course can represent a risk factor for auditory function particularly for organ of Corti. This complicates the attempt of separate pure presbycusis from socioacusis. Research indicated some "longevity genes" and longevity-promoting life-styles (obesity and correlated conditions like hyperlipidemia, hypercholesterolemia, hypertension, hyperhomocysteinemia and cardiovascular disease, smoking, diet and diabetes [2,3]. Age-related hearing loss seems to occur more frequently in industrial population than in non-industrial [4]. The relation between alleles pro or against-aging and environment maybe play a determinant role in the evolution of hearing with aging. Until such genes are identified, the best strategy is to reduce environmental risk factors (noise exposure, ototoxic drugs, industrial solvents or combinations of these)
Warped Phenomenology of Higher-Derivative Gravity
We examine the phenomenological implications at colliders for the existence
of higher-derivative gravity terms as extensions to the Randall-Sundrum model.
Such terms are expected to arise on rather general grounds, e.g., from string
theory. In 5-d, if we demand that the theory be unitary and ghost free, these
new contributions to the bulk action are uniquely of the Gauss-Bonnet form. We
demonstrate that the usual expectations for the production cross section and
detailed properties of graviton Kaluza-Klein resonances and TeV-scale black
holes can be substantially altered by existence of these additional
contributions. It is shown that measurements at future colliders will be highly
sensitive to the presence of such terms.Comment: 29 pages, 8 figure
Problems of regulation in financial markets
© Medwell Journals, 2017. The development of economic processes in the contemporary peace requires symmetrical efforts for guaranteeing the stability of markets as a whole and financial markets in particular. The development of financial markets is located under the effect of the development of economic systems and vice versa. In this connection questions of the adequate evolution of financial supervision become very urgent. In the study, problems and questions of the activity of mega-regulator in Russia in the context of the world experience of active financial policy and regulation of financial markets are illuminated. Are examined prospects, problems and marks of possible versions. The conceptual vision of nature of the development of the mega-regulation of financial markets as immanent institute in the social-economic system is stated
Multibound soliton formation in an erbium-doped ring laser with a highly nonlinear resonator
We have studied the generation of low-noise ultrashort multibound solitons in the telecommunication spectral window in an erbium-doped all-fiber ring laser with a highly-nonlinear resonator mode-locked by a nonlinear polarization evolution effect. The multibound soliton generation is obtained with more than 20 bound dechirped pulses with a duration of 240 fs at a repetition rate of 11.3 MHz (with a signal-To-noise ratio of 73.3 dB), the relative intensity noise is <-140 dBc/Hz, and the Allan deviation of the repetition frequency does not exceed with a time averaging window of 100 s
Advanced code-division multiplexers for superconducting detector arrays
Multiplexers based on the modulation of superconducting quantum interference
devices are now regularly used in multi-kilopixel arrays of superconducting
detectors for astrophysics, cosmology, and materials analysis. Over the next
decade, much larger arrays will be needed. These larger arrays require new
modulation techniques and compact multiplexer elements that fit within each
pixel. We present a new in-focal-plane code-division multiplexer that provides
multiplexing elements with the required scalability. This code-division
multiplexer uses compact lithographic modulation elements that simultaneously
multiplex both signal outputs and superconducting transition-edge sensor (TES)
detector bias voltages. It eliminates the shunt resistor used to voltage bias
TES detectors, greatly reduces power dissipation, allows different dc bias
voltages for each TES, and makes all elements sufficiently compact to fit
inside the detector pixel area. These in-focal-plane code-division multiplexers
can be combined with multi-gigahertz readout based on superconducting
microresonators to scale to even larger arrays.Comment: 8 pages, 3 figures, presented at the 14th International Workshop on
Low Temperature Detectors, Heidelberg University, August 1-5, 2011,
proceedings to be published in the Journal of Low Temperature Physic
Black Hole Production at the LHC by Standard Model Bulk Fields in the Randall-Sundrum Model
We consider the production of black holes at the LHC in the
Randall-Sundrum(RS) model through the collisions of Standard Model(SM) fields
in the bulk. In comparison to the previously studied case where the SM fields
are all confined to the TeV brane, we find substantial suppressions to the
corresponding collider cross sections for all initial states, i.e., ,
and , where represents a light quark or anti-quark which lie close to
the Planck brane. For quarks, which are closer to the TeV brane, this
suppression effect is somewhat weaker though quark contributions to the
cross section are already quite small due to their relatively small parton
densities. Semi-quantitatively, we find that the overall black hole cross
section is reduced by roughly two orders of magnitude in comparison to the
traditional TeV brane localized RS model with the exact value being sensitive
to the detailed localizations of the light SM fermions in the bulk.Comment: 14 pages, 3 figs; refs and discussion adde
Multibound solitons generation with a controllable number of bound states in a passive mode-locked all-fiber erbium-doped ring laser
We have studied generation of stable and low-noise de-chirped ultrashort solitons in bound states and we have experimentally demonstrated the formation multi-bound solitons with the controllable number of bound states 7 < N < 17 by pump power variation. A numerical simulation of the influence of various types of fluctuations on the generation mode was also carried out
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