150 research outputs found
Tenfold Magnetoconductance in a Non-Magnetic Metal Film
We present magnetoconductance (MC) measurements of homogeneously disordered
Be films whose zero field sheet conductance (G) is described by the
Efros-Shklovskii hopping law . The low field
MC of the films is negative with G decreasing 200% below 1 T. In contrast the
MC above 1 T is strongly positive. At 8 T, G increases 1000% in perpendicular
field and 500% in parallel field. In the simpler parallel case, we observe {\em
field enhanced} variable range hopping characterized by an attenuation of
via the Zeeman interaction.Comment: 9 pages including 5 figure
Angular dependence of the magnetic-field driven superconductor-insulator transition in thin films of amorphous indium-oxide
A significant anisotropy of the magnetic-field driven
superconductor-insulator transition is observed in thin films of amorphous
indium-oxide. The anisotropy is largest for more disordered films which have a
lower transition field. At higher magnetic field the anisotropy reduces and
even changes sign beyond a sample specific and temperature independent magnetic
field value. The data are consistent with the existence of more that one
mechanism affecting transport at high magnetic fields.Comment: 4 pages, 5 figure
MICROWAVE HEATING APPLICATIONS IN WASTE REDUCTION AND ENVIRONMENTAL ENGINEERING
The reported study was funded by RFBR, project number 21-58-53044
Superconductivity on the localization threshold and magnetic-field-tuned superconductor-insulator transition in TiN films
Temperature- and magnetic-field dependent measurements of the resistance of
ultrathin superconducting TiN films are presented. The analysis of the
temperature dependence of the zero field resistance indicates an underlying
insulating behavior, when the contribution of Aslamasov-Larkin fluctuations is
taken into account. This demonstrates the possibility of coexistence of the
superconducting and insulating phases and of a direct transition from the one
to the other. The scaling behavior of magnetic field data is in accordance with
a superconductor-insulator transition (SIT) driven by quantum phase
fluctuations in two-dimensional superconductor. The temperature dependence of
the isomagnetic resistance data on the high-field side of the SIT has been
analyzed and the presence of an insulating phase was confirmed. A transition
from the insulating to a metallic phase is found at high magnetic fields, where
the zero-temperature asymptotic value of the resistance being equal to h/e^2.Comment: 5 pages, 4 eps figures, RevTeX4, Published versio
Density of states and magnetoconductance of disordered Au point contacts
We report the first low temperature magnetotransport measurements on
electrochemically fabricated atomic scale gold nanojunctions. As , the
junctions exhibit nonperturbatively large zero bias anomalies (ZBAs) in their
differential conductance. We consider several explanations and find that the
ZBAs are consistent with a reduced local density of states (LDOS) in the
disordered metal. We suggest that this is a result of Coulomb interactions in a
granular metal with moderate intergrain coupling. Magnetoconductance of atomic
scale junctions also differs significantly from that of less geometrically
constrained devices, and supports this explanation.Comment: 5 pages, 5 figures. Accepted to PRB as Brief Repor
Ambipolar gate effect and low temperature magnetoresistance of ultrathin La0.8Ca0.2MnO3 Films
Ultrathin La0.8Ca0.2MnO3 films have been measured in a field-effect geometry.
The electric field due to the gate produces a large ambipolar decrease in
resistance at low temperatures. This is attributed to the development of a
pseudogap in the density of states and the couple of localized charge to
strain. The gate effect and mangetoresistance are interpreted in a consistent
framework. The implications for the low temperature behavior of a manganite
film in the two dimensional limit are discussed.Comment: 4 pages, 3 figure
Electron-electron interaction at decreasing
The contribution of the electron-electron interaction to conductivity is
analyzed step by step in gated GaAs/InGaAs/GaAs heterostructures with different
starting disorder. We demonstrate that the diffusion theory works down to , where is the Fermi quasimomentum, is the mean free
paths. It is shown that the e-e interaction gives smaller contribution to the
conductivity than the interference independent of the starting disorder and its
role rapidly decreases with decrease.Comment: 5 pages, 6 figure
Preparation and Characterization of the Extracellular Domain of Human Sid-1
In C. elegans, the cell surface protein Sid-1 imports extracellular dsRNA into the cytosol of most non-neuronal cells, enabling systemic spread of RNA interference (RNAi) throughout the worm. Sid-1 homologs are found in many other animals, although for most a function for the protein has not yet been established. Sid-1 proteins are composed of an N-terminal extracellular domain (ECD) followed by 9–12 predicted transmembrane regions. We developed a baculovirus system to express and purify the ECD of the human Sid-1 protein SidT1. Recombinant SidT1 ECD is glycosylated and spontaneously assembles into a stable and discrete tetrameric structure. Electron microscopy (EM) and small angle x-ray scattering (SAXS) studies reveal that the SidT1 ECD tetramer is a compact, puck-shaped globular particle, which we hypothesize may control access of dsRNA to the transmembrane pore. These characterizations provide inroads towards understanding the mechanism of this unique RNA transport system from structural prospective
ЭЛЕКТРО- И ЛАЗЕРОКОАГУЛЯЦИЯ В ХИРУРГИИ ОКОЛОУШНЫХ СЛЮННЫХ ЖЕЛЕЗ
Using electric and laser coagulation during the operations on parotid gland was analyzed in experiment, containing 30 cavies, which were divided into 2 groups; and during the operative treatment of parotid gland benign tumors in the group of 10 patients.Проанализировано применение электро- и лазерокоагуляции при оперативных вмешательствах на околоушной слюнной железе в эксперименте на 30 морских свинках и в клинических условиях при оперативном лечении доброкачественных опухолей околоушной железы 20 пациентов
- …