Theoretical analysis of the tautomer composition of cytosine isolated in an Ar matrix

The IR spectra of cytosine and its five tautomers are calculated and analyzed in the B3LYP/6-31G(d) approximation. Comparison of calculated and experimental spectra showed that, in the isolated state, there occur four tautomeric forms, cis, trans, trans-amino-hydroxy, and cis-imino-oxo, as well as one canonical form of cytosine.     

Production of heavy quarks on protons within the semihard QCD approach

The inclusive production of heavy quarks in p\(\bar p\) interactions at the Tevatron and LHC energies is considered within the semihard QCD approach. The dependence of the total and differential cross sections for the production of b quarks and B mesons (and of muons originating from the subsequent semileptonic decay B → μν _μ X) on various samples of unintegrated gluon distributions is studied. The results obtained by calculating azimuthal correlations between the transverse momenta of final particles are presented. The theoretical results are compared with the latest experimental data obtained by the D0 and CDF Collaborations at the Tevatron.     

Elliptic Linear Problem for Painlevé VI Equation with Spectral Parameter

We introduce a linear problem with a spectral parameter for the elliptic form of the Painlevé VI equation. The corresponding nonautonomous version produces the Lax pair with spectral parameter for the Calogero-Inozemtsev model with a single degree of freedom.     

Heavy-quark production in p $$\bar p$$ collisions and unintegrated gluon distributions

The inclusive production of heavy (c and b) quarks in high-energy p\(\bar p\) collisions are considered within the semihard approach in QCD. The dependence of the cross section for heavy-quark production, σ(p_T>p _T ^min ), on unintegrated gluon distributions is studied. The results of this consideration are compared with experimental data obtained by the D0 and CDF Collaborations at Tevatron.     

Amidation of Ethyl N-Benzoyl-1-adamantylacetimidate

Russian Journal of General Chemistry -     

Self-assembly formation of the ordered nanostructure arrays induced by Be interaction with Si(1 1 1) surface

Formation of the beryllium (Be) submonolayers on the Si(1 1 1)7 × 7 surface has been studied using scanning tunneling microscopy. It has been found that Be interaction with Si(1 1 1) at 500-700 °C results in a self-assembly formation of the four various types of the highly-ordered nanostructure arrays. The nanostructure arrays develop on top of the “soft” silicide layer, which period and orientation alter with the nanostructure growth: the shorter the nanostructure period, the larger the rotation angle. The main structural parameters of the silicide layer and nanostructure arrays have been established.     

Effect of the loading rate, angle of orientation of fibers, and temperature on the strength properties of birch

The present paper reports results of analysis of the strength and strain properties of birth wood at different loading rates, sample temperatures, and angles of orientation of fibers relative to the direction of loading. Dynamic tests (v=10 m/sec) with axial compression of the samples were conducted by the Kol'skii method on a setup with a Hopkinson compound rod. Noticeable dynamic strengthening of samples with angles of orientation of fibers α=0 and 5° was observed. At test temperatures +65, +20, and −30°C, the dynamic strength is higher than the quasistatic strength by approximately 23, 31, and 42% respectively. Institute of Experimental Physics, Sarov 607190. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 39, No. 6, pp. 154–158, November–December, 1998.     

Effect of gas environment parameters on operation efficiency of chemical absorbents of carbon dioxide

Effect of main characteristics of the gas medium on the absorbing properties of alkaline chemical absorbents is demonstrated. The following gas flow parameters were examined as variables: carbon dioxide content of the gas flow within the range 0.2–5.0 vol %, gas humidity of 25–90 rel %, and pressure in the zone of the chemisorption process in the range from 2 to 6 MPa. As objects of study served mixed chemical absorbents based on calcium, sodium, and lithium hydroxides.