Photocatalytic Conversion of a FeCl<Subscript>3</Subscript>–CCl<Subscript>4</Subscript>–ROH System

The photocatalytic transformations of carbon tetrachloride and aliphatic primary alcohols in the presence of iron trichloride and a molar ratio of components FeCl₃: CCl₄: ROH = 1: 300: 2550 were studied. CCl₄ is transformed into chloroform and hexachloroethane after exposure to a mercury lamp (250 W) to the FeCl₃–CCl₄–ROH system at 20°C, whereas the primary ROH alcohols are selectively oxidized into acetals (1,1-dialkoxyalkanes). The maximum conversion of CCl₄ reaches 80%. The kinetics and mechanism of the photocatalytic conversion of the FeCl₃–CCl₄–ROH system are considered.     

About Cosmic Ray Sources in Galaxy

Physics of Atomic Nuclei - In the last two decades the new experimental data on cosmic rays concerning energy spectra in a wide energy range up to 10 $${}^{14}$$ eV, isotropy, ratio of positron...     

Mechanical properties of a composite with a carbonized matrix

The effect of reinforcement schemes that differ in the magnitude of the disorientation angle of neighboring filler layers on the mechanical properties of a "carbon-carbon" composite under extension, compression, or bending is shown.Translated from Mekhanika Polimerov, No. 2, pp. 235–240, March–April, 1976.     

Rainfalls during great Forbush decreases

Summary The changes of rainfall values during great Forbush decreases recorded by the low-latitudinal neutron monitor of Huancayo (47 events from 1956 through 1992) were examined. The data on precipitations were taken from the State of S?o Paulo and from the Amazonian region, Brazil. As a rule, the data from more than 50 meteorological stations were used for each events. The main result is the following: during strong decreases of cosmic-ray flux in the atmosphere (great Forbush decreases) the precipitation value is decreased. The effect of rainfall changes is seen more distinctly if wet seasons are considered.     

Latitude effect of muons in the Earth’s atmosphere during solar activity minimum

The results of muon flux measurements (E ≥ 70 MeV) in the atmosphere during solar activity minimum are reported. The measurements were performed during Antarctic sea expedition in 1975–1976 at several geomagnetic locations (from 1 to 14 GV). The experimental data obtained made it possible to determine the latitude effect of muons in the distribution at different levels in the atmosphere. The Geant4 program was used to simulate the galactic cosmic ray transport in the Earth’s atmosphere and evaluate the angular and spectral distributions (p, e^?/e⁺, photons, muons) at different atmospheric levels. The experimental and simulated results are in satisfactory agreement.     

Ground state of π-conjugated polymer chains forming an intermolecular charge-transfer complex as probed by Raman spectroscopy

The intermolecular charge-transfer complex (CTC) between the conjugated polymer MEH-PPV and the low-molecular organic acceptor trinitrofluorenone (TNF) has been studied by Raman and optical absorption spectroscopy. On mixing MEH-PPV with TNF, an absorption band due to the CTC appeared in the optical gap of the polymer, whereas, in the Raman spectra, characteristic bands of the polymer are shifted and their widths and intensities change. The low-frequency shift of the strongest band at 1580 cm^?1 in the Raman spectrum of the polymer, assigned to the symmetric stretching vibration of the phenyl group, is shown to be due to electron density transfer from the π-conjugated system of the polymer to the acceptor and is as large as 5 cm^?1, which corresponds to a charge transfer on the order of 0.1e ^?1. Even at a low acceptor concentration (one TNF molecule per 10 monomer units of the polymer), most Raman-active conjugated chains are involved in the CTC. It is suggested that conjugated segments of the polymer can form a CTC of variable composition MEH-PPV: TNF = 1: X, where 0.1 ≤ X ≤ 0.5 (for each monomer unit of the polymer), and one TNF molecule can thereby interact with two conjugated segments of MEH-PPV. The conjugated polymer chains involved in the CTC can become more planar, and their interaction with the local environment can noticeably change; however, their conjugation length, most likely, remains unaltered.     

On the Reproduction of the Solar Activity Variations in the Range 2–40 Months in the Interplanetary Medium

Journal of Experimental and Theoretical Physics - We compare the quasi-biennial variations and Rieger-type variations (on a timescale of less than 1&nbsp;year) in solar activity, interplanetary...     

Spectral peculiarities of high energy X-ray radiation,gamma radiation,and Submillimeter radio emission in the impulsive phase of a solar flare

We analyze experimental data on the temporal behavior of fluxes and energy spectra of hard solar X-ray and gamma radiation in the energy range of 0.015 to 300 MeV, obtained onboard the CORONAS-F satellite during a solar flare on August 25, 2001. These data are compared with measurements of the radio emission fluxes over the wide frequency range of 1–405 GHz. For our analysis, we use data obtained onboard the YOHKOH, TRACE and GOES satellites, along with ground-based observations of this solar event using the Solar Submillimeter Telescope (SST; Argentina). For the first time, we find nearly simultaneous changes in the energy spectra of gamma radiation over the range 10–150 MeV and the frequency spectrum of radio emission at the beginning and during a impulsive phase of this event (whose duration did not exceed three minutes).     

Cosmic ray variations recorded by the CARPET facility on March 7, 2011

The CARPET cosmic ray detector was installed in 2006 in the Argentinean Andes at an altitude of 2550 m at the El Leoncito Astronomical Complex (CASLEO) in San Juan, Argentina (S31.8, W69.3; R _c = 9.659.65 GV). This instrument was developed at the Lebedev Physical Institute (LPI) in Russia as part of an international collaboration between the LPI, Brazil’s Mackenzie Center for Radioastronomy and Astrophysics (CRAAM), and the CASLEO. This work presents the results from analyzing variations in cosmic ray intensity recorded by the CARPET facility during the solar proton event of March 7, 2011. Also used in our analysis were the experimental data obtained by the GOES, FERMI, and ISS spacecraft during this solar event.     

A 19F NMR study of products of hexafluorobutadiene sulfotrioxidation

The products of hexafluorobutadiene sulfotrioxidation were identified by ¹⁹F NMR. The major products are hexafluoro-1-butene-3,4-β-sultone, hexafluoro-2-butene-1,4-sultone, hexafluoro-1-butene-3,4-pyrosultone, and hexafluoro-2-buten-1,4-diyl sulfate.