Spectroscopic factors and nuclear vertex constants from the (p,d) reactions on7Li,9Be and13C nuclei

The angular distributions of the (p, d) reactions on the⁷Li,⁹Be and¹³C nuclei have been analysed within the framework of the new approach to the extraction of the structural information from the direct nuclear reactions. In this method the additional physical information on the nuclear vertex constants is introduced into the standard DWBA calculations, which makes possible to eliminate the strong dependence of the spectroscopic factors on the geometry of bound state potentials. The possibility of the model — independent determination of the spectroscopic factors — is discussed.The authors wish to express their gratitude to I. Borbely for assistance in the calculations by the method of subtraction of singularities.     

Evolution of defect substructure of metal alloys at microscopic and mesoscopic level under torsion

Transmission electron microscopy was used to investigate the reorientation of crystal lattice during the formation of ultrafine-grained (UFG) copper, nickel, and an alloy of Ni–18% Al–8% Cr–1% Zr–0.15% B (at.%) under severe plastic deformation by equal-channel angular (ECA) pressing and twisting at a high quasi-hydrostatic pressure. The crystal lattice was found to transform into a UFG state; it is fragmented at the nano-, micro-, and mesoscale levels. Possible mechanisms for the reorientation of the crystal lattice under deformation at the micro- and mesoscale level are discussed.     

Reaction of 4-chlorohexafluoro-2,5-cyclohexadienyl fluorosulfate and hexafluoro-2,5-cyclohexadienylene 1,4-bis(fluorosulfate) with nucleophilic reagents

Conclusions In reactions with nucleophilic reagents, 4-chlorohexafluorodienyl fluorosulfate and hexafluoro-2,5-hexadienylene 1,4-bis(fluorosulfate) display a dual reactivity due to attack of the nucleophile at both the sulfur atom and the carbon atom to which the fluorosulfate groups is attached.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 375–379, February, 1987.     

A field of free electrons formed as a result of pulsed gamma radiation passing through a liquid medium

A method for describing the change in an electromagnetic field created by electrons generated by a narrow beam of gamma rays passing through a liquid medium is proposed. Results from calculations using this procedure can be employed in designing detectors for experiments in high-energy physics.     

Specific features of etching of ultrafine- and coarse-grained titanium in base and acid solutions of hydrogen peroxide

The character and kinetics of chemical etching of nanostructured titanium in base (NH₄OH/H₂O₂) and acid (H₂SO₄/H₂O₂) solutions of hydrogen peroxide (Piranha) were studied. A study of the etching kinetics showed that the etching rate of the nanostructured titanium is not constant and tends to decrease, but in the case of the sulfuric acid solution the decrease is smoother owing to the growth of the oxide layer. The etching rate for ultrafine-grained titanium is higher than for the coarse-grained sample. The applied significance of the study is associated with the fact that Piranha solutions show promising for cleaning, hydrophilizing, and making rough the titanium surface for use in medical implants.     

Simulation of the magnetic and magnetocaloric properties of hydrides of the La(Fe0.88Si0.12)13 compound by applying a negative pressure

Based on the model calculation, it has been shown that the effect of hydration of the ferromagnetic compounds La(Fe_0.88Si_0.12)₁₃H _y is quantitatively adequately described by the introduction of a negative pressure. The calculations have been performed for compounds with hydrogen concentrations y = 0, 0.5, 1.0, and 1.5. It has been found that these concentrations correspond to the pressures P = 0, ?0.95, ?1.85, and ?2.80 GPa, respectively. The calculated Curie temperature, magnetization, characteristics of the magnetocaloric effect, and other properties are in satisfactory agreement with experiment.     

Effect of hydrostatic pressure on the magnetic and lattice properties of the ferromagnet La(Fe0.86Si0.14)13

The temperature dependence of the lattice constant of the ferromagnet La(Fe_0.86Si_0.14)₁₃ has been measured at different pressures and temperatures. The numerical value of the bulk modulus at room temperature has been determined. The measurements of the temperature dependence of the lattice constant of the ferromagnet La(Fe_0.86Si_0.14)₁₃ at zero pressure and at 11.5 kbar have demonstrated that, at zero pressure, the lattice constant sharply decreases in the range from 160 to 210 K, whereas at a pressure of 11.5 kbar, the lattice constant decreases in the range from 110 to 180 K. This indicates that the Curie temperature T _C changes from 210 to ～170 K under pressure. The experimental results have been analyzed using the equations of states for the magnetic and elastic subsystems of the ferromagnet.     

Antiarrhythmic agents based on diterpenoid alkaloid lappaconitine. Protonation of N-deacethyllappaconitine in methanol solutions

Russian Chemical Bulletin - The data on antiarrhythmic drugs based on diterpene alkaloid lappaconitine are summarized. N-Deacetyllappaconitine is the main metabolite of allapinin and a potential...