Production of exotic isotopes in complete fusion reactions with radioactive beams

The isotopic dependence of the complete fusion (capture) cross section is analyzed in the reactions $^{130,132,134,136,138,140,142,144,146,148,150}$Xe+$^{48}$Ca with stable and radioactive beams. It is shown for the first time that the very neutron-rich nuclei $^{186-191}$W can be reached with relatively large cross sections by complete fusion reactions with radioactive ion beams at incident energies near the Coulomb barrier. A comparison between the complete fusion and fragmentation reactions for the production of neutron-rich W and neutron-deficient Rn isotopes is performed.Comment: 13 pages, 6 figures, accepted in PR

Op\u27i͡ani͡ela, Op. 150

https://scholarexchange.furman.edu/periphery-kharbintsy2/1018/thumbnail.jp

Description of a new species of Chrysina Kirby, 1828 (Coleoptera: Scarabaeidae: Rutelinae) from resplendens group, based on morphological characters and mtDNA COX I molecular marker

A new species of the genus Chrysina Kirby, 1828 is decribed from Panama. Chrysina kalinini sp.n. is related to Chrysina resplendens (Boucard, 1875) in habitus, male genitalia morphology and mtDNA COX I molecular marker). The two closely related species differ in the shape of pronotum, mesosternal process and male genitalia. mtDNA COI molecular marker analysis gives a reliable distance for the compared species

Анализ возможности увеличения дальности стрельбы перспективных управляемых ракет для отечественных реактивных систем залпового огня

The article considers a possibility to increase a flying range of the perspective rockets equipped with the control unit with aerodynamic controllers for the multiple launch rocket systems “Smerch”.To increase a flying range and reduce a starting mass of the rocket, the paper studies a possibility to replace the single-mode rocket engine used in the solid-fuel rocket motor for the direct-flow propulsion jet engine (DFPJE) with not head sector air intakes. The DFPJE is implemented according to the classical scheme with a fuel charged in the combustion chamber. A separated solid propellant starting accelerator provides the rocket acceleration to reach a speed necessary for the DFPJE to run.When designing the DFPJE a proper choice of not head air intake parameters is one of the most difficult points. For this purpose a COSMOS Flow Simulation software package and analytical dependences were used to define the following: a boundary layer thickness where an air intake is set, maximum permissible and appropriate angles of attack and deviation angles of controllers at the section where the DFPJE works, and some other parameters as well.Calculation of DFPJE characteristics consisted in determining parameters of an air-gas path of the propulsion system, geometrical sizes of the pipeline flow area, sizes of a fuel charge, and dependence of the propulsion system impulse on the flight height and speed. Calculations were performed both in thermodynamic statement of problem and in using software package of COSMOS Flow Simulation.As a result of calculations and design engineering activities the air intake profile is created and mass-dimensional characteristics of DFPJE are defined. Besides, calculations of the starting solid fuel accelerator were carried out. Further design allowed us to create the rocket shape, estimate its mass-dimensional characteristics, and perform ballistic calculations, which proved that achieving a range of 120 km for the rocket is possible.Thus, with restrictions imposed by the control unit, application of DFPJE allows us to increase a flying range of the rocket more than by 30% in comparison with the existing domestic samples.Предложен способ повышения дальности стрельбы перспективной управляемой ракеты для отечественной реактивной системы залпового огня за счет применения прямоточного воздушно-реактивного двигателя и блока управления. Разработана компоновочная схема ракеты и проведены расчеты прямоточного воздушно-реактивного двигателя с использованием методов математического моделирования и пакетов прикладных программ, подтверждающие возможность реализации предложенного технического решения. Получены конкретные значения повышения дальности стрельбы и показана возможность улучшения характеристик ракеты для отечественной реактивной системы залпового огня до уровня зарубежных аналогов. DOI: 10.7463/aersp.0315.078198

НАПРАВЛЕНИЯ ПОВЫШЕНИЯ ДОЛГОВЕЧНОСТИ ИЗДЕЛИЙ ЛЕТАТЕЛЬНЫХ АППАРАТОВ

In the article different increasing directions of fatigue strength are considered, but the reasons of sudden distraction are not determined. The sudden distraction with fatigue appearance problem is designated. The fatigue strength increasing direction by aviation technology products technical condition systematic monitoring and the most dangerous distraction points detection with the use of acoustic emission method are suggested.В статье рассматриваются различные направления повышения усталостной прочности, но не определяются причины возникновения внезапного разрушения. Обозначена проблема возникновения неожиданного разрушения при усталости. Предлагается направление повышения усталостной прочности проведением систематического контроля технического состояния изделий авиационной техники и выявление наиболее опасных очагов разрушения с применением акустической эмиссии

Elastic Mid-Infrared Light Scattering: a Basis for Microscopy of Large-Scale Electrically Active Defects in Semiconducting Materials

A method of the mid-IR-laser microscopy has been proposed for the investigation of the large-scale electrically and recombination active defects in semiconductors and non-destructive inspection of semiconductor materials and structures in the industries of microelectronics and photovoltaics. The basis for this development was laid with a wide cycle of the investigations on the low-angle mid-IR-light scattering in semiconductors. The essence of the technical idea was to apply the dark-field method for spatial filtering of the scattered light in the scanning mid-IR-laser microscope. This approach enabled the visualization of large-scale electrically active defects which are the regions enriched with ionized electrically active centers. The photoexcitation of excess carriers within a small volume located in the probe mid-IR-laser beam enabled the visualization of the large-scale recombination-active defects like those revealed in the optical or electron beam induced current methods. Both these methods of the scanning mid-IR-laser microscopy are now introduced in detail in the present paper as well as a summary of techniques used in the standard method of the lowangle mid-IR-light scattering itself. Besides the techniques for direct observations, methods for analyses of the defect composition associated with the mid-IR-laser microscopy are also discussed in the paper.Comment: 44 pages, 13 figures. A good oldi