566 research outputs found
Shape of a magnetic resonance line in a thin film on the surface of anisotropic superconductor with irregularly distributed Abrikosov's vortices
The form of an electron paramagnetic resonance (EPR) in a thin paramagnetic film (λ/10, λ-London's depth of magnetic field penetration into superconductor) overlying the surface of an anisotropic superconductor is calculated taking into account the local magnetic field non-uniformity of an irregular Abrikosov's vortex lattice. It is shown that the form of EPR is noticeably varied with the degree of irregularity of the superconductor vortex lattice. It is suggested that an inclusion of this circumstance into consideration may essentially change the conclusions made on the lattice type and parameters of this superconductor, which are typically derived from the analysis of the EPR form. © Springer Science+Business Media, Inc. 2007
Distribution of a Local Magnetic Field in Superconductors with an Uncorrelated Random Lattice of Abrikosov Vortices
The distribution of a local magnetic field near the surface of a uniaxial anisotropic type-II superconductor is determined in the framework of the London model in the case when the Abrikosov vortices are randomly distributed in the superconductor. The distribution of a local magnetic field is obtained as a function of the distance from the surface of the superconductor. It is demonstrated that the shape of the distribution of the local magnetic field near the surface differs substantially from that in the bulk of the superconductor. This difference should be taken into account in interpreting experimental data on the local magnetic field in the surface region of the superconductor and in thin superconducting films (with a thickness of less than or equal to λ, where λ is the depth of penetration of the magnetic field into the superconductor). It is shown that, as in the case of a regular lattice of vortices, the value of λ, can be determined from observations of the distribution of the local magnetic field in type-II superconductors with an uncorrelated random lattice of vortices. © 2004 MAIK "Nauka/ Interperiodica"
Shape of the nuclear magnetic resonance line in anisotropic superconductors with an irregular vortex lattice
The NMR line shape in type-II superconductors has been constructed with allowance for a change in the nonuniform magnetic field of an irregular vortex lattice near the surface of a superconductor. The NMR line shape is shown to change as a function of the irregularity of the vortex lattice rather that being simply broadened. This change is related to a lowering of the local symmetry of the irregular vortex lattice in the superconductor. This circumstance can substantially change the conclusions regarding the vortex-lattice type and the superconductor parameters that are usually drawn from the NMR line shape. © Pleiades Publishing, Inc., 2006
Normal Pressure Hydrocephalus as an Unusual Presentation of Supratentorial Extraventricular Space-Occupying Processes: Report on Two Cases
Normal pressure hydrocephalus (NPH) is a clinical and radiographic syndrome characterized by ventriculomegaly, abnormal gait, urinary incontinence, and dementia. The condition may occur due to a variety of secondary causes but may be idiopathic in approximately 50% of patients. Secondary causes may include head injury, subarachnoid hemorrhage, meningitis, and central nervous system tumor. Here, we describe two extremely rare cases of supratentorial extraventricular space-occupying processes: meningioma and glioblastoma multiforme, which initially presented with NPH
Interlayer interaction, shear vibrational mode, and tribological properties of two-dimensional bilayers with a commensurate moir\'e pattern
The potential energy surface (PES) of interlayer interaction of infinite
twisted bilayer graphene is calculated for a set of commensurate moir\'e
patterns using the registry-dependent Kolmogorov-Crespi empirical potential.
The calculated PESs have the same shape for all considered moir\'e patterns
with the unit cell size of the PES which is inversely related to the unit cell
size of the moir\'e pattern. The amplitude of PES corrugations is found to
decrease exponentially upon increasing the size of the moir\'e pattern unit
cell. An analytical expression for such a PES including the first Fourier
harmonics compatible with the symmetries of both layers is derived. It is shown
that the calculated PESs can be approximated by the derived expression with the
accuracy within 1%. This means that different physical properties associated
with relative in-plane motion of graphene layers are interrelated and can be
expressed analytically as functions of the amplitude of PES corrugations. In
this way, we obtain the shear mode frequency, shear modulus, shear strength and
barrier for relative rotation of the commensurate twisted layers to a fully
incommensurate state for the considered moir\'e patterns. This barrier may
possibly lead to the macroscopic robust superlubricity for twisted graphene
bilayer with a commensurate moir\'e pattern. The conclusions made should be
valid for diverse 2D systems of twisted commensurate layers.Comment: 9 pages, 3 figures; Supplemental Material: 2 pages, 1 figur
Experimental Designs for Binary Data in Switching Measurements on Superconducting Josephson Junctions
We study the optimal design of switching measurements of small Josephson
junction circuits which operate in the macroscopic quantum tunnelling regime.
Starting from the D-optimality criterion we derive the optimal design for the
estimation of the unknown parameters of the underlying Gumbel type
distribution. As a practical method for the measurements, we propose a
sequential design that combines heuristic search for initial estimates and
maximum likelihood estimation. The presented design has immediate applications
in the area of superconducting electronics implying faster data acquisition.
The presented experimental results confirm the usefulness of the method. KEY
WORDS: optimal design, D-optimality, logistic regression, complementary log-log
link, quantum physics, escape measurement
Elication of an excitation center in the depth of tissue by visualization with high-frequency electric field
Hardware and software system, which makes it possible to visualize the glow center, marker of the excitation center in tissue, in the electric field, is created. The system was tested in 14 experiments with sinoatrial nodes of cat's hearts, which's fist excitation's center is in the depth of the right auricle's myocardium, and in 30 experiments with frog's venous sinuses, which's first excitation's center is situated in the superficial layer of the sinus wall. Also observations were held with deeply situated center - in cat's tooth's pulp, which is surrounded by insulators: dentine and tooth's enamel. The ability of visualization the excitation's center was developed at localizations in different depths
The International Society for the Study of Women's Sexual Health Process of Care for the Identification of Sexual Concerns and Problems in Women
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