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A. Soldatov

Publications and source records attributed to A. Soldatov.

5 recordsLinked to original sources

Three-dimensional structure of a single colloidal crystal grain studied by coherent x-ray diffraction

A coherent x-ray diffraction experiment was performed on an isolated colloidal crystal grain at the coherence beamline P10 at PETRA III. Using azimuthal rotation scans the three-dimensional (3D) scattered intensity in reciprocal space from the sample was measured. It includes several Bragg peaks as well as the coherent interference around these peaks. The analysis of the scattered intensity reveals the presence of a plane defect in a single grain of the colloidal sample. We confirm these findings by model simulations. In these simulations we also analyze the experimental conditions to phase 3D diffraction pattern from a single colloidal grain. This approach has the potential to produce a high resolution image of the sample revealing its inner structure, with possible structural defects.

cond-mat.mtrl-sci

Effects of high pressure on the physical properties of MgB2

The synthesis of MgB2-based materials under high pressure gave the possibility to suppress the evaporation of magnesium and to obtain near theoretically dense nanograined structures with high superconducting, thermal conducting, and mechanical characteristics: critical current densities of 1.8-1.0 \cdot 106 A/cm2 in the self field and 103 A/cm2 in a magnetic field of 8 T at 20 K, 5-3 \cdot 105 A/cm2 in self field at 30 K, the corresponding critical fields being HC2 = 15 T at 22 K and irreversible fields Hirr =13 T at 20 K, and Hirr =3.5 T at 30 K, thermal conduction of 53+/-2 W/(m \cdot κ), the Vickers hardness Hv=10.12+/-0.2 GPa under a load of 148.8 N and the fracture toughness K1C = 7.6+/-2.0 MPa m0.5 under the same load, the Young modulus E=213 GPa. Estimation of quenching current and AC losses allowed the conclusion that highpressure-prepared materials are promising for application in transformer-type fault current limiters working at 20-30 K.

cond-mat.supr-con

Use of high throughput sequencing to observe genome dynamics at a single cell level

With the development of high throughput sequencing technology, it becomes possible to directly analyze mutation distribution in a genome-wide fashion, dissociating mutation rate measurements from the traditional underlying assumptions. Here, we sequenced several genomes of Escherichia coli from colonies obtained after chemical mutagenesis and observed a strikingly nonrandom distribution of the induced mutations. These include long stretches of exclusively G to A or C to T transitions along the genome and orders of magnitude intra- and inter-genomic differences in mutation density. Whereas most of these observations can be explained by the known features of enzymatic processes, the others could reflect stochasticity in the molecular processes at the single-cell level. Our results demonstrate how analysis of the molecular records left in the genomes of the descendants of an individual mutagenized cell allows for genome-scale observations of fixation and segregation of mutations, as well as recombination events, in the single genome of their progenitor.

q-bio.GN

Prospects to measure neutrino oscillation pattern with very large area underground detector at very long baselines

The concept of a very long baseline neutrino experiment with quasi monochromatic neutrino beam and very large area underground detector is discussed. The detector could be placed in the existing 20 km tunnel at IHEP, Protvino. The High Intensity Proton Accelerators (HIPA) which are planned to be built in Japan (JAERI-KEK, baseline of 7000 km) and Germany (GSI, baseline of 2000 km) as well as the Main Injector at Fermilab (7600 km) are considered as possible sources of neutrino beams. The oscillations are analysed in the three-neutrino scheme taking into account terrestrial matter effects. In the proposed experiment it is feasible to observe the oscillation pattern as an unique proof of the existence of neutrino oscillations. Precise measurements of disappearance oscillation parameters of the muon neutrinos and antineutrinos can be done within a reasonable time.

hep-ph

Search for Exotic Mesons in pi- P Interactions at 18 GeV/c

The recent search for non $q \bar{q}$ mesons in $π^{-}p$ interactions at Brookhaven National Laboratory is summarized. Many final states such as $ηπ$, $η' π^{-}$, $a_{0} π$, $f_{1} π$, $a_{2} π$, $b_{1} π$, which are favored decay modes of exotics, are under investigation.

hep-ex