Estimation of the stability of the strength of glass-reinforced plastics in conical shells

On the basis of a statistical analysis of the test data it is shown that there is a difference between the mechanical characteristics (in tension and compression) of laminated glass-reinforced plastics obtained under laboratory and industrial conditions by impregnation under pressure in a closed mold. The stability of the strength properties of the glass-reinforced plastic in various conical shells, produced in large batches, is considered. Certain experimental relations between the material properties and the total number of shells produced are also established.Moscow. Translated from Mekhanika Polimerov, No. 1, pp. 102–108, January–February, 1970.     

C‐phosphorylation of 5,10‐dimethyl‐5,10‐dihydrophenazine and its carbo‐ and heteroanalogs

This study covers phosphorylation of heterocyclic analogues of N‐methyldiphenylamine with phosphorus tribromide in pyridine solution. The reaction is found to proceed regioselectively in accordance with the orienting effect of the amino group. Mono and bis‐phosphorylated derivatives of the heterocycles have been isolated and characterized. It is pointed out that the heterocyclic systems under study exhibit reduced reactivity in electrophilic phosphorylation as compared to N‐methyldiphenylamine. The results of calculations by the PM3 method are reported for the starting molecules and their σ‐complexes. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:652–657, 2001     

Electron capture dissociation of polypeptides in a three-dimensional quadrupole ion trap: Implementation and first results

The adverse influence of the radio frequency (RF) voltage on electrons has been the main obstacle for the implementation of electron capture dissociation (ECD) in three-dimensional quadrupole ion traps (3D QITs). Here we demonstrate that the use of axial magnetic field, together with the injection of low-energy (<5 eV) electrons, in the beginning of the positive RF semi-period achieves trapping of electrons for a period of time comparable with the semi-period duration. Importantly, the energy of the electrons remains low during most of the trapping period. With this technique, which we call "magnetized electrons, in-phase injection" (MEPhI), ECD and other ion-electron reactions have become possible in a 3D QIT. Initial ECD results, including single-scan data, were obtained with dications of Substance P. The observed secondary fragmentation of ECD fragments indicates that the trapped electrons are still somewhat hotter than desired.     

Biodegradation of Polyhydroxyalkanoate Films in Natural Environments

Summary: Biodegradation of film specimens from polyhydroxyalkanoates (PHAs) of two types – poly-3-hydroxybutyrate (PHB) and poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV) – was analysed in different environments: tropical sea waters of the South China Sea (Nha Trang, Vietnam) and soils in the environs of Hanoi (Vietnam), Nha Trang (Vietnam) and Krasnoyarsk (Siberia, Russia). In seawater, the mass loss of the specimens of both types was almost equal. However, in tropical soils, PHB degraded quicker than PHBV. In the Siberian soil, the degradation rate of the PHBV was generally higher than that of PHBV. Analysis of molecular mass of PHA specimens showed its decreasing during biodegradation. In the tropical sea conditions, PHA degrading microorganisms were represented by bacteria of Enterobacter, Bacillus and Gracilibacillus genera. Among PHA degrading bacteria, Burkholderia, Alcaligenes, Bacillus, Mycobacterium and Streptomyces genera were identified in Vietnamese soils, and Variovorax, Stenotrophomonas, Acinetobacter, Pseudomonas, Bacillus and Xanthomonas genera in Siberian soils. Micromycetes of Gongronella, Paecilomyces, Penicillium and Trichoderma genera exhibited PHA degrading activity in Vietnamese soils, and Paecilomyces, Penicillium, Acremonium, Verticillium and Zygosporium genera – in Siberian soils.     

Defects in the GaAs and InGaAs layers grown by low-temperature molecular-beam epitaxy

The problem of defect formation in the GaAs and InGaAs layers grown by low-temperature molecular-beam epitaxy is discussed. The effect of growth conditions (temperature and flux ratio between the elements of groups III and V) on the morphology of growth surface, internal structure, type, and concentration of electrically-and optically active defects is analyzed. A comparison is made between the defect formation processes occuring during the epitaxial growth and post-growth annealing of the layers. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 63–72, December, 2006.