Interpretation of neutrino-matter interactions at low energies as contraction of gauge group of Electroweak Model

The very weak neutrino-matter interactions are explained with the help of the gauge group contraction of the standard Electroweak Model. The mathematical contraction procedure is connected with the energy dependence of the interaction cross section for neutrinos and corresponds to the limiting case of the Electroweak Model at low energies. Contraction parameter is connected with the universal Fermi constant of weak interactions and neutrino energy as j ²(s) = $\sqrt {G_F s} $ .     

Effect of electropulsing treatment on the microstructure and superelasticity of TiNi alloy

Cold-rolled TiNi alloy was treated by electropulsing with different process parameters. The superelasticity, electrical resistivity and microstructure evolution of the TiNi alloy were investigated. The recrystallization is found to happen in the cold-rolled TiNi alloys during electropulsing treatment (EPT) processing and it took 9 s to complete the crystallization in the EPT process. In addition, the grain size increases with the charge voltage and the discharge frequency of the electropulse. The maximum superelasticity of 6.94 % is gained when the TiNi alloy is treated by the electropulsing with the frequency of 300 Hz. The short recrystallization time of the alloy is attributed to the acceleration of atomic diffusion and the movement velocity of the grain boundary by electropulsing. This research provides an in-depth understanding of how the electropulsing affects the microstructure and superelasticity of TiNi alloy.     

Processes Proceeding in Fe–0.12C–1Cr–1Mo–1V Steel after Pressure Cycling

The evolution of the phase content and morphology and crystalline defects during temperature and pressure cycling is studied by the methods of transmission electron microscopy and x-ray diffraction analysis. Thermostable Fe–0.12C–1Cr–1Mo–1V steel in the initial ferrite-pearlite state is examined. The evolution of the grain structure and dislocation density is quantitatively described. A low stability of large pearlite grains at temperatures above 600°C is established. The problem of oxidizing of steel of this class is also discussed.     

Simulation of optical response to complex formation of crown-containing 2-styrylbenzothiazoles with alkaline-earth metals

The photochromic properties and complex formation of 2-styrylbenzothiazoles containing different crown ether moieties with alkaline-earth metals were described using optical methods, NMR spectroscopy, and HPLC. The large ionochromic effect and fluorescence quenching on complex formation with alkali-earth metal cations were found for 2-styrylbenzothiazole containing the phenylazacrown ether moiety. The small ionochromic effect and fluorescence enhancement of complex formation with alkali-earth metal cations were found for 2-styrylbenzothiazole containing the benzocrown ether moiety. cis-Isomers of 2-styrylbenzothiazoles were stable in the dark in acetonitrile. The method for separation of cis-isomers of 2-styrylbenzothiazoles by HPLC was proposed.     

Evolution of a Martensite Packet under Multicycle Fatigue Loading

The methods of diffraction electron microscopy of thin metal foils are used to study the defect substructure and the phase content of preliminary quenched Fe–0.60C–1Mn–2Si steel subjected to multicycle fatigue tests. It is demonstrated that steel loading is accompanied by the initial stage of dynamic recrystallization. One of the mechanisms of forming dynamic recrystallization centers is the pair coalescence of packet martensite crystals.     

Background structure in the Heidelberg-Moscow experiment on the search and investigation of double beta decay of 76Ge1

Independent analysis of the spectra from the Heidelberg-Moscow experiment has been carried out. A direct comparison of the peak intensities in the spectra allows for the conclusion that in the energy range up to 3200 keV the background is due to the detection of γ rays from the decay of trace impurities of anthropogenic and cosmogenic nuclides occurring in the apparatus between the HPGe detectors and the main (Pb and Cu) shielding. The ²²⁶Ra, ²¹⁴Pb, and ²¹⁴Bi γ rays observed in the spectra are shown to arise in the ²²⁶Ra rather than ²³⁸U decay chain. The estimates of the expected intensities of the weak ²¹⁴Bi γ rays in the spectrum region around Q _ββ(⁷⁶Ge) = 2039 keV do not contradict the observation of the peak at 2039 keV as claimed by Klapdor-Kleingrothaus and coauthors. The text was submitted by the authors in English.     

The chemistry of the surface of modified detonation nanodiamonds of different types

The influence of standard chemical treatment used to extract interstellar nanodiamonds from meteorites on the chemical composition of the surface of synthetic nanodiamonds with substantially different properties was studied by thermal desorption mass spectrometry and IR spectroscopy. The chemistry of the surface of nanodiamonds after treatment was substantially different from that of initial particles. The suggestion was made that the chemical structure of the surface of diamond particles in the interstellar space could be reconstructed from the data on meteorite diamonds. Mass spectrometric studies also gave information about possible mechanisms of the release of noble gases from meteorite diamonds at various temperatures.     

Spectroscopic properties,structure, and photoinduced motion of 4-(2-naphthyl)pyridine in cyclodextrin cavities

Spontaneous and photoinduced protonation of 4-(2-naphthyl)pyridine (1) in solutions and in complexes with β-cyclodextrin (β-CD) and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) was studied using the absorption and fluorescence spectroscopies. The structures and stabilities of complexes of compound 1 and its quaternized derivative, 1-methyl-4-(2-naphthyl)pyridinium perchlorate (3), with β-CD and HP-β-CD were examined by ¹H NMR titration (logK = 1.5–2.3). The molecule of naphthylpyridine 1 is always in the cyclodextrin cavity, regardless of the pH value of the solution. 2-Hydroxypropyl-β-cyclodextrin binds better the neutral form of compound 1 than does β-CD, while naphthylpyridinium salts exhibit nearly equal affinities to both cavitands. According to spectroscopic data, pK _a (1) is 5.12 in water, which favors protonation of the N atom both in the ground and excited states; as a result, the fluorescence spectrum exhibits only the band of the protonated form with a lifetime of 15 ns. The addition of HP-β-CD to a solution of naphthylpyridine 1 results in the formation of inclusion complex 1@HP-β-CD, lowers pK _a to 4.62, and gives rise to a fluorescence band of the nonprotonated form of compound 1 with a lifetime of 1.25 ns. Therefore, the presence of compound 1 in the HP-β-CD cavity precludes its protonation in the excited state. The initial portions of the fluorescence curves for compound 1 in solution and in its complex with HP-β-CD obtained upon pulsed excitation were compared to propose the initiation mechanism of short-lived fluorescence of the nonprotonated form of naphthylpyridine 1. Quantum chemical modeling of the protonation and complexation of compound 1 in the presence of water was performed. Based on the results obtained, a reversible photoinduced mechanical motion of naphthylpyridine 1 in the HP-β-CD cavity was suggested.     

Design of crystal packings of styrylheterocycles and [2+2] photocycloaddition reactions in their single crystals 6. Synthesis and crystal packings of neutral crown-containing and model styrylheterocycles

Neutral crown-containing and model styrylheterocycles of the 4-pyridine, 4-quinoline, and 9-acridine series were synthesized under acidic catalysis. The influence of the molecular geometry of these compounds, as well as of related styrylheterocycles of the 2-benzothiazole and benzobisthiazole series, on the formation of a particular crystal packing was investigated based on X-ray diffraction data. An extension of the conjugation system in the molecules can result in the sandwich-herringbone packing motif as the only one of the three packing motifs most typical of this class of compounds. This packing provides the preorganization of the structural units for the [2+2] photocycloaddition reaction. The styrylheterocycle containing the bulky 9-acridine moiety is nonplanar due to strong intramolecular steric interactions. The packing motifs formed by nonplanar molecules do not provide the preorganization of the molecules for the [2+2] photocycloaddition. The introduction of the crown ether moiety into the benzene ring of the styrylheterocycle can decrease the predictability of the packing motif as a result of the inclusion of solvent molecules capable of hydrogen bonding with the heteroatoms of the macrocycle in the crystal structure.