An overview of the results obtained by foreign seismologists based on the records of Turkish seismic networks AFAD (State Agency for Disaster Management under the Ministry of Internal Affairs) is ...presented. The sequence of earthquakes began with the
M
7.8 main shock and includes thousands of aftershocks. The strongest events occurred in the first twelve hours, with the sources of two
M
7.0+ events located 100 km apart. Earthquakes have caused ground motions that are destructive to structures, the so-called “pulse-like waveforms,” and epicentral distances, as was previously noted, are not a good indicator of attenuation of waves from earthquakes with extended ruptures.The records of stations in the near-fault zones clearly revealed the directivity effects of seismic radiation. The
M
7.8 earthquake (main shock) was larger than expected in the current tectonic setting. The near-field records traced an early transition to the super-shear (~1.55
V
s
) rupture propagation on the Narli lateral fault, where the rupture originated and then passed into the East Anatolian fault. The early transition to the super-shear stage obviously contributed to the further propagation of the rupture and the initiation of slips on the East Anatolian fault. A dynamic fracture model has been constructed that matches the various results of inversions obtained by different authors and reveals spatially inhomogeneous rupture propagation velocities. Super-shear velocities exceeding the shear wave velocity
V
s
are observed along the Narli lateral fault and at the southwestern end of the East Anatolian fault. Since the late 1990s, seismologists have been working on incorporating the rupture directivity effects of extended sources into the probabilistic seismic hazard analysis procedures, but no consensus has been reached so far, and progress in this area can only be expected with the accumulation of a sufficient amount of observational data.
This work presents data on the possibility and perspectives of using bismuth silicate as a filler for a radiation–shielding composite based on the polyimide matrix. The aim of this work was to ...experimentally estimate the protective characteristics of this polymer composite during the passage of electron energy (from 1 to 6 MeV) and gamma ray energy (0.4 MeV and 0.662 MeV). For a larger range of energy, theoretical calculations for the passage of electrons and gamma radiation through the composite were used. The introduction of the proposed filler in an amount of 70 wt% reduced the effective range of the electron by two times in the polyimide. The absorption coefficient of electrons in the proposed composite was much greater than the coefficient of reflection for electrons of the same energy. As the initial energy of the electron increases, the effect of their reflection decreases and the effect of their absorption increases. According to experimental data, the linear attenuation coefficients at 0.5 MeV and 0.662 MeV of energy were 0.87 ± 0.10 cm–1 and 0.39 ± 0.04 cm–1, respectively. At an energy of 0.5 MeV, the linear attenuation coefficient for the composite was 2.5 times and 1.4 times more than that of aluminum at an energy of 0.5 MeV and 1 MeV, respectively. The difference between the estimated and experimental data was small (around 8–11%), such that the calculated and the experimental results were in agreement.
•Composites of polyimide with bismuth silicate were exposed to electron and gamma radiation.•The experimental methods and theoretical calculations were used.•The introduction of the filler reduced the effective range of the electron by two times.•The protective properties of polyimide composites with traditional materials were compared.•The calculated and the experimental results were in agreement.
This paper continues a series of papers in which simultaneous
matrix solutions of two scalar evolution equations, which are analogs of time-dependent Schrödinger equations, were constructed. In the ...constructions in the present paper, these equations correspond to the Hamiltonian system
—one of the representatives of the hierarchy of degenerations of the isomonodromic Garnier system. The mentioned hierarchy was described by H. Kimura in 1986. In terms of solutions of linear systems of differential equations in the method of isomonodromic deformations, the consistency condition for which is the Hamiltonian equations of the
system, the constructed simultaneous matrix solutions of analogs of time-dependent Schrödinger equations are written out explicitly in this paper.
—To obtain realistic and correct estimates of seismic effects in the Baikal Rift Zone (BRZ), a ground motion prediction equation has been developed based on the records of local earthquakes ...(magnitudes
m
b
~ 3.4–5.5, hypocentral distances
R
~ 15–220 km) obtained by Ulan-Ude and Severomuisk seismic stations. At the first step, in our previous works, using stochastic simulation of the accelerograms of the recorded local earthquakes we estimated the regional parameters of radiation and propagation of seismic waves (stress drop in an earthquake source, quality function of the medium, geometrical spreading, wave attenuation at high frequencies, local site amplification, etc). These parameters were then used to generate a set of earthquake accelerograms over a wide range of magnitudes (
M
w
~ 4.0–8.0) and distances (
R
~ 1–200 km) on a rock site, and a ground motion prediction equation (GMPE) describing the dependence of peak ground accelerations (PGA) and peak ground velocities (PGV) on magnitude and distance are constructed. The obtained PGA estimates are compared with those estimated from GMPE recommended for BRZ by the international Global Earthquake Model (GEM) project. The scatter of the estimates obtained based on GEM GMPE indicates the relevance of developing the own GMPEs for Russian regions based on the records of local earthquakes. The GMPE derived in this work can be used for seismic hazard assessment in the BRZ eastern part and will be updated as new data are acquired.
•BaFe1/2Sn1/2O3-δ was obtained using the sol-gel method and additional O2 treatment.•Oxygen treatment increases Fe4+ content from 27% to 36%.•The absorption band is strongly broadened and shifted to ...the visible and IR regions.•Oxygen treatment results in significant increase of conductivity.•BaFe1/2Sn1/2O3-δ exhibits giant dielectric response in a wide frequency range.
Barium ferrostannate BaFe1/2Sn1/2O3-δ was obtained using the sol-gel precursor method and additional annealing in O2. Phase purity of ceramics was confirmed by x-ray diffraction, the microstructure and microanalysis of grains were investigated by scanning electron microscopy methods, whereas the valence states and coordination of tin and iron ions were determined using Mössbauer spectroscopy. We found out that as-sintered and O2-treated samples contain 27% and 36% of six-coordinated Fe4+ ions, respectively, whereas Fe3+ ions are five-coordinated. Oxygen treatment results in a decrease of the average sizes of coherent scattering regions, increase of the local distortion of SnO6 octahedra, and significant increase of conductivity. Experiments on diffuse reflection show that the characteristic absorption band is strongly broadened and shifted to the visible and IR regions, which is explained by the formation of a large number of local donor levels in the band gap. Thus, the optical band gap is reduced by Fe-doping as compared to BaSnO3 and can be additionally adjusted by annealing in oxygen. Both as-sintered and O2-treated BaFe1/2Sn1/2O3-δ ceramics exhibit giant dielectric response in a wide frequency range.
We construct joint
matrix solutions of the scalar linear evolution equations
with times
and
, which can be treated as analogues of the time-dependent Schrödinger equations. These equations correspond ...to the so-called
Hamiltonian system, which is a representative of a hierarchy of degenerations of the isomonodromic Garnier system described by Kimura in 1986. This compatible system of Hamiltonian ordinary differential equations is defined by two different Hamiltonians
,
, with two degrees of freedom corresponding to the time variables
and
. In terms of solutions of the linear systems of ordinary differential equations obtained by the isomonodromic deformation method, with the compatibility condition given by the Hamilton equations of the
system, the constructed compatible solutions of analogues of the time-dependent Schrödinger equations are presented explicitly. We also present a change of variables relating the matrix solutions of analogues of the time-dependent Schrödinger equations defined by two forms of the
system (rational and polynomial in coordinates). This system is a quantum analogue of the well-known canonical transformation relating the Hamilton equations of the
system in these two forms.
The Russian Academy of Sciences and Federal Space Agency, together with the participation of many international organizations, worked toward the launch of the RadioAstron orbiting space observatory ...with its onboard 10-m reflector radio telescope from the Baikonur cosmodrome on July 18, 2011. Together with some of the largest ground-based radio telescopes and a set of stations for tracking, collecting, and reducing the data obtained, this space radio telescope forms a multi-antenna ground-space radio interferometer with extremely long baselines, making it possible for the first time to study various objects in the Universe with angular resolutions a million times better than is possible with the human eye. The project is targeted at systematic studies of compact radio-emitting sources and their dynamics. Objects to be studied include supermassive black holes, accretion disks, and relativistic jets in active galactic nuclei, stellar-mass black holes, neutron stars and hypothetical quark stars, regions of formation of stars and planetary systems in our and other galaxies, interplanetary and interstellar plasma, and the gravitational field of the Earth. The results of ground-based and inflight tests of the space radio telescope carried out in both autonomous and ground-space interferometric regimes are reported. The derived characteristics are in agreement with the main requirements of the project. The astrophysical science program has begun.
•Polyimide/Pb multilayer coatings are obtained.•Pb was obtained by electrodeposition at various potentials: −200, −400 and −600 mV.•Cylindrical Pb wires with a 25-μm thickness and 200 ± 10 nm in ...diameter are obtained.•The unit cell parameter for the obtained lead nanowires is found to be 4.959 Å.•The tensile strength of multilayer coatings with a 300-μm thickness is 76 MPa.
Multilayer coatings are obtained by “bonding” several layers of polyimide track membranes filled with metallic lead. The bonding of the layers is carried out by an imidization reaction, specifically, the production of polyimide from polyamic acid at 250–270 °C and a pressure of 200 MPa for 30 min. To fill the pores with nanodispersed lead, we use galvanic deposition of metallic lead through the etched channels of the polyimide track membranes. This study presents data on the electrodeposition of nanodispersed lead, including the formation of a cathode coating, the electrolyte used and the optimal electrolysis conditions. Potentiostatic curves obtained during electrodeposition of lead into pores with a diameter of 200 nm at various fixed potentials (−200, −400 and −600 mV) are presented. It is established that as a result of electrodeposition, the channels are completely filled, as evidenced by the formation of lead nanowires. According to the results of X-ray diffraction, the nanowires are metallic lead with a pronounced cubic crystal structure of Fm3m, with no additional peaks detected. The diffraction peaks of lead nanowires are slightly wider compared to bulk lead. The resulting multilayer coating with a thickness of 300 μm has high physicomechanical and dielectric properties with a tensile strength of 76 MPa, an elongation in tension of 10.2% and a specific volume resistivity of 103 Ω m.
We have performed experiments on the generation of relativistic electron beams in helium gas jets (electron density ∼1020 cm−3) using a femtosecond Ti : sapphire laser. Electron beams with a total ...charge of 0.2−0.5 nC, a maximum electron energy of up to 60 MeV, and a divergence of up to 300 mrad are recorded. The generated electron beams are converted into bremsstrahlung X-rays using a Ta plate 2 mm thick. The average dose of bremsstrahlung radiation in the air at a distance of 1 m from the source was 5.4 ±1.7 mrad per pulse. The emitting region size measured by the blurriness of the X-ray image is about 650 μm (FWHM).
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