369 research outputs found
Quasi one dimensional transport in individual electrospun composite nanofibers
We present results of transport measurements of individual suspended electrospun nanofibers Poly(methyl methacrylate)-multiwalled carbon nanotubes. The nanofiber is comprised of highly aligned consecutive multiwalled carbon nanotubes. We have confirmed that at the range temperature from room temperature down to ∼60 K, the conductance behaves as power-law of temperature with an exponent of α ∼ 2.9−10.2. The current also behaves as power law of voltage with an exponent of β ∼ 2.3−8.6. The power-law behavior is a footprint for one dimensional transport. The possible models of this confined system are discussed. Using the model of Luttinger liquid states in series, we calculated the exponent for tunneling into the bulk of a single multiwalled carbon nanotube αbulk ∼ 0.06 which agrees with theoretical predictions
АНАЛИЗ ПРОГНОСТИЧЕСКИХ ФАКТОРОВ ПОВТОРНОГО ОБРАЗОВАНИЯ ПОЛИПОВ ЖЕЛУДКА ПОСЛЕ ЭНДОСКОПИЧЕСКОЙ ПОЛИПЭКТОМИИ
Проанализированы результаты лечения 1450 больных, которым в плановом порядке в хирургических отделениях Луганской областной клинической больницы произведена эндоскопическая полипэктомия по поводу единичных и множественных полипов желудка (ПЖ), предраковых изменений. Признаками неблагоприятного прогноза, достоверно влияющими на повторное образование ПЖ, считали: число ПЖ, их размеры, локализацию, наличие эрозий в слизистой оболочке ПЖ. Повторное образование большинства полипов в антральном отделе желудка можно объяснить особенностями микроциркуляторных нарушений в его слизистой оболочке
A 2D position sensitive germanium detector for spectroscopy and polarimetry of high-energetic x-rays
We report on a first prototype 2D μ-strip germanium detector, developed at IKP-Jülich, and its performance test at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. Beside an accurate determination of the detector response function, the polarization sensitivity has been addressed in this study. For this purpose photon beams at energies of 60 keV and 210 keV have been used
Polarization transfer in Rayleigh scattering of hard x-rays
Wereport on the first elastic hard x-ray scattering experiment where the linear polarizationcharacteristics of both the incident and the scattered radiation were observed. Rayleigh scattering wasinvestigated in a relativistic regime by using a high-Z target material, namely gold, and a photon energyof 175keV. Although the incident synchrotron radiation was nearly 100% linearly polarized, at ascattering angle of q = 90we observed a strong depolarization for the scattered photonswith adegree of linear polarization of +0.27% 0.12%only. This finding agreeswith second-orderquantum electrodynamics calculations of Rayleigh scattering, when taking into account a smallpolarization impurity of the incident photon beam which was determined to be close to 98%. Thelatter value was obtained independently from the elastic scattering by analyzing photons that wereCompton-scattered in the target. Moreover, our results indicate that when relying on state-of-the-arttheory, Rayleigh scattering could provide a very accurate method to diagnose polarization impuritiesin a broad region of hard x-ray energies
An X-ray photoelectron spectroscopy study of the products of the interaction of gaseous IrF6 with fine UO2F2
Nuclear fuel reprocessing by fluorination, a dry method of regeneration of spent nuclear fuel, uses UO2F2 for the separation of plutonium from gaseous mixtures. Since plutonium requires special treatment, IrF6 was used as a thermodynamic model of PuF6. The model reaction of the interaction of gaseous IrF6 with fine UO2F2 in the sorption column revealed a change of color of the sorption column contents from pale-yellow to gray and black, indicating the formation of products of such an interaction. The X-ray photoelectron spectroscopy study showed that the interaction of gaseous IrF6 with fine UO2F2 at 125 °C results in the formation of stable iridium compounds where the iridium oxidation state is close to Ir3+. The dependence of the elemental compositions of the layers in the sorption column on the penetration depth of IrF6 was established
Draft genome sequences of gammaproteobacterial methanotrophs isolated from marine ecosystems
The genome sequences of Methylobacter marinus A45, Methylobacter sp. strain BBA5.1, and Methylomarinum vadi IT-4 were obtained. These aerobic methanotrophs are typical members of coastal and hydrothermal vent marine ecosystems
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