An integral equation analysis of thick irises in waveguides of a phased array antenna

Показано застосування методу інтегральних рівнянь часткових областей, що пере-тинаються для розв‘язання задачі дифракції електромагнітної хвилі на нескінченій фа-зованій антенній решітці, хвилеводи якої мають діафрагми кінцевої товщини. Отрима-но значення коефіцієнта відбиття для різних розмірів діафрагм.In this paper the integral equation method for overlapping partial domains has been ap-plied to solving the electromagnetic wave diffraction problem on a phased array antenna, which waveguides have irises of a finite thickness. The dependences of the reflection coeffi-cient magnitude and phase on the value of steering phase shift for different iris dimensions are obtained

Acoustic Response to the Action of Nanosecond Laser Pulses on an In/CdTe Thin-Film Heterostructure

The photothermoacoustic method has been used for diagnostics of thermobarodynamic processes in the metal In(400 nm)/semiconductor (CdTe) thin-film system under nanosecond laser irradiation (7 ns, λ = 532 nm) in natural conditions (in air) and in a liquid medium (water). From the analysis of the data obtained, the dependence of the pressure induced in the energy-release region on the irradiation energy den-sity has been established and the melting threshold of In film has been determined. Under irradiation of In/CdTe in water, the pressure is higher than in air: 17 times higher at the melting threshold of In film and 30 times higher at twice the temperature. It has been found that the laser pulse treatment of In/CdTe/Au samples in water makes it possible to obtain diode structures with better parameters: smaller leak currents and a steeper current-voltage characteristic under the forward bias of the p-n junction

Структура и свойства литейного магниевого сплава GEWZ522K системы Mg–Gd–Nd–Y–Zn–Zr

The article discusses the solidification and phase composition of the (wt.%) Mg–4.8Gd–2.1Nd–1.6Y–0.4Zn–0.6Zr (GEWZ522K) casting alloy. It is demonstrated that in the as-cast state, the alloy structure comprises primary zirconium particles, dendrites of the magnesium solid solution (αMg), and eutectic intermetallic phases located between dendritic branches. Following solution heat treatment at t = 530±5 °C, the alloy transitions into a single-phase state and can be significantly strengthened through artificial aging after quenching. It is recommended to apply alloy aging at t = 250 °C for 8–10 h or at t = 200 °C for 15–18 h. This approach leads to the maximum strengthening of the alloy, with the best mechanical properties achieved for the alloy aged at t = 250 °C. Regardless of the aging method used, the ultimate tensile strength (UTS) of the samples surpasses 300 MPa, which significantly exceeds that of commercial casting alloys according to GOST 2856-79. The measured corrosion rate for the GEWZ522K alloy is 7.5±0.4 mm/year, that slightly higher than that for the less alloyed commercial alloy ML10 (approximately 2.5 mm/year) tested under similar conditions. Furthermore, the alloy was subjected to tests for ignition resistance when in contact with air. It was observed that with continuous airflow over the specimen’s surface, ignition centers appear at t = 625 °C due to the breakdown of the oxide film, causing the alloy to nearly completely melt. Therefore, the GEWZ522K alloy can be employed as a high-strength casting alloy. However, during the operation of cast parts, particular attention must be paid to safeguarding the surface of these parts against corrosion. Рассмотрены кристаллизация и фазовый состав литейного сплава (мас.%) Mg–4,8Gd–2,1Nd–1,6Y–0,4Zn–0,6Zr (GEWZ522K). Показано, что в литом состоянии структура сплава состоит из первичных частиц циркония, дендритов магниевого твердого раствора αMg и эвтектических интерметаллических фаз, находящихся между их ветвями. В результате отжига при t = 530±5 °C сплав переходит в однофазное состояние и после закалки может быть значительно упрочнен в результате искусственного старения. Было предложено проводить старение сплава при t = 250 °C длительностью 8–10 ч или при t = 200 °C в течение 15–18 ч. При этом достигается максимальное упрочнение сплава, однако лучшие механические свойства были получены для сплава, состаренного при t = 250 °C. Независимо от режима старения, предел прочности на растяжение (σв) образцов превосходит 300 МПа, что гораздо выше показателей промышленных литейных сплавов по ГОСТ 2856-79. Рассчитанная скорость коррозии для сплава GEWZ522K равна 7,5±0,4 мм/год, что несколько больше, чем для менее легированного промышленного сплава МЛ10 (порядка 2,5 мм/год), испытанного в аналогичных условиях. Сплав был также испытан на сопротивление к возгоранию в контакте с воздухом. Установлено, что при непрерывном поступлении воздуха к поверхности образца очаги возгорания появляются при t = 625 °C вследствие разрушения оксидной плены, когда сплав практически полностью расплавляется. Таким образом, сплав GEWZ522K может быть использован в качестве высокопрочного литейного сплава. Однако при эксплуатации литых деталей из него необходимо уделять пристальное внимание защите их поверхности от коррозионного воздействия.

IONIC CONDUCTIVITY IN LAYERED PEROVSKITE SrLa2Sc2O7

The layered perovskite SrLa2Sc2O7 was investigated as a protonic conductor for the first time. The synthesis was performed using solid state method. The possibility of water absorption was proved by thermogravimetric measurements. The conductivity was measured by changing T and pH2O

STATE OF THE ART OF CANCER CARE DELIVER Y IN MOSCOW

Abstract:The globally increased concern with the situation, existing in oncology, is conditioned by a steady incidence rate of malignant neoplasms, having a tendency to its growth. Annually over 7 million people die in the world due to cancer, by 2020, according to WHO estimations, this index will increase to 10 million. By the end of the 2013 report year patient population with cancer, registered in cancer care facilities of the Russian Federation, is 3 098 855 (2 995 566 in 2012), i. e. 2,1% of the population of the country. The system of cancer care delivery to the population in the Russian Federation and in Moscow is aimed at an early diagnostics and prevention of malignant neoplasms. Municipal cancer care service establishes the patients’ routes at suspicion on oncological disease and determines the functions of all links of health care for this type of patients. Stateof-the-art delivery of oncological specialty care has been built up with account of modern demands and is functionally structured in accordance with tree-level municipal health care system