The first results of observations of acoustic signals generated by cosmic ray muons in a seismically stressed medium

The first results of observations of acoustic signals generated by high-energy muons of extensive air showers, which propagate in a seismically stressed medium are presented. The cosmophysical method for monitoring the volume stressed state is tested using the experimental setup developed in the earthquake-prone region of Almaty at the Tien Shan High-Altitude Scientific Station of the Lebedev Physical Institute. High-amplitude acoustic signals correlated with the passage and interaction of muon groups in the Earth’s crust are detected for the first time.     

Magnetic relaxation spectrum of ferrites Mn x Fe3−x O4+γ

The initial permeability disaccommodation in ferritesMn _x Fe₃–xO₄₊ , 0·5x1, was studied in a temperature range around –200°C to +180°C. Four separate bands were found in the relaxation spectrum of these ferrites.

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Mn _x Fe_3–x O₄₊

Mn _x Fe_3–x O₄₊ , 0,5x1, –200°C +180°C. .

     

Measuring optical characteristics of the atmosphere with a laser heterodyne system

A laser heterodyne system for measuring optical characteristics of a turbulent atmosphere is described. Continuous readout data on the fluctuations in the phase of the radiation propagating in a channel in the atmosphere are presented. These data can be used to determine the major parameters of the turbulent state. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 6, pp. 906–908, November–December, 2008.     

Dimethylmalonoyl peroxide – the neglected lowest homologue: simple synthesis and high reactivity

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Aluminosilicate surfaces as promoters for peptide bond formation: an assessment of Bernal's hypothesis by ab initio methods

The role in prebiotic chemistry that Br?nsted and Lewis sites, both present at the surface of common aluminosilicates, may have played in favoring the peptide bond formation has been addressed by ab initio methods within a cluster approach. B3LYP/6-31+G(d,p) free energy potential energy surfaces have been fully characterized for the model reaction glycine + NH3 --> 2-NH2 acetamide (mimicking the true 2 Gly --> GlyGly one) occurring on (i) a Lewis site, (ii) a Br?nsted site, and (iii) a combined action of Lewis/Br?nsted sites. Compared to the gas-phase (gp) activation free energy of 50 kcal/mol, the Lewis site alone reduces the gp barrier to 41 kcal/mol, whereas the activation by the Br?nsted site dramatically reduces the barrier to about 18 kcal/mol. Nevertheless, formation of the prereactant complex in this latter case will rarely occur, since water will easily displace the glycine molecule interacting with the Br?nsted site. However, if a realistic feldspar surface with neighboring Br?nsted and Lewis sites is considered, the proper prereactant complex is highly stabilized by a simultaneous interaction with the Lewis and the Br?nsted sites, in such a way that the Lewis site strongly attaches the glycine molecule to the surface whereas the Br?nsted site efficiently catalyzes the condensation reaction, showing that the interplay between Lewis/Br?nsted sites is an important issue. The free energy barrier computed for the realistic feldspar surface model is 26 kcal/mol. The role of dispersive interactions on the free energy barrier and the stabilization of the final product, not accounted for by the B3LYP functional, have been estimated and shown to be substantial. Speculations about further elongation of the formed dipeptide have been put forward on the basis of the relatively strong interaction energy of the formed GlyGly dipeptide with the aluminosilicate surface.     

Self-oscillations of two bodies in the case of nonlinear friction

The motion of two bodies is studied. One of them is attached to a fixed base by a spring, whereas the other one is attached to a body moving at a constant velocity. The interaction of the bodies is described by a nonlinear friction law with a falling section of the characteristic. The averaged equations of motion are obtained in terms of the canonical action-angle variables. The stationary points corresponding to self-oscillation modes are found and their stability is studied.     

Synthesis of Acyclic Geminal Bis-peroxides

Russian Journal of Organic Chemistry - The review covers the state of the art in methods of synthesis of acyclic geminal bis-peroxides, including bis-hydroperoxides, bis(1-hydroperoxyalkyl)...     

Determination of gold by atomic absorption spectrometry after extraction into the non-desulphurized fraction of crude oil distillate

The extraction of gold from aqueous chloride solutions into non-desulphurized fractions of crude oil distillates, especially paraffin oil, is described. The fraction boiling at 150–220°C exhibited optimum properties. The extraction is tested for solutions containing chlorides, dissolved chlorine and 0.1–3 M hydrochloric acid. Nitric acid should be absent. The distribution coefficient of gold varies from 400 to 900. Extracts containing ? 0.3 g l^?1 gold are stable for at least 12 months. The organic extract is sprayed into a lean acetylene/air flame with measurement at 242.8 nm (background correction). The calibration graph has linear portions over the ranges 0–2.5 and 2.5–16 mg l^?1. The limit of detection is 0.03 mg l^?1 gold in the extract (0.001 mg l^?1 in the aqueous phase). The minimum measurable concentration for gold in auriferous rocks and ores is 0.018 g per ton with 25-g samples.