Характеристики полых стеклянных микросфер и проектирование легких полимерных композиционных материалов различного состава и дисперсной структуры

Currently, to obtain light polymer composite materials with high strength characteristics, hollow microspheres of various nature (glass, quartz, polymer, etc.) are used as fillers. Hollow glass microspheres of different grades (manufactured by JSC «SIO Stekloplastik») were studied by various methods, the disperse structure was described using the generalized parameters model, the light dispersion-filled polymer composite materials (DFPCM) were classified according to the structural principle, generalized and reduced parameters were calculated, and the structure, compositions of light CMs on polymer matrices of various nature were designed.В настоящее время для получения легких полимерных композиционных материалов (КМ) с высокими прочностными характеристиками в качестве наполнителей используют полые микросферы различной природы (стекло, кварц, полимер и т. д.). Исследовали упаковки полых стеклянных микросфер разных марок (производства АО «НПО Стеклопластик») различными методами, описана дисперсная структура с помощью модели обобщенных параметров, произведена классификация легких дисперсно-наполненных полимерных композиционных материалов (ДНПКМ) по структурному принципу, рассчитаны обобщенные и приведенные параметры, спроектированы структуры, составы легких КМ на полимерных матрицах различной природы

Advances in ITER-relevant Nb-Ti and Nb3_{3}Sn strands and low-loss Nb-Ti strands in RF

The review of the main results of R&D directed on the enhancement of ITER relevant NbTi and Nb$_{3}$Sn strands performance recently carried out in Russia (the Bochvar Institute) are presented. For ITER PF type (NbTi) strands with Cu/non Cu ratio of 1.6 the attainment of ITER specified critical current density (Jc) ≥ 2900 A/mm2 (5 T, 4.2 K) has been shown. For Toroidal Field (TF) strands (Nb$_{3}$Sn) the influence of doping and layout peculiarities of the wires produced by bronze method on their current-carrying ability has been investigated. It was shown that with non-doped matrix and doped filaments Jc exceeds 800 A/mm2 (12 T, 4.2 K) while with the application of the doped bronze and nondoped filaments it exceeds 900 A/mm2. Internal-tin Nb$_{3}$Sn strand meeting the ITER TF specification requirements was also developed and fabricated. The results of testing of CICC samples in a SULTAN facility have shown that performance parameters are higher than ITER qualification requirements Low loss model fine filament NbTi strands, intended for operating in fields with a ramp rate from 1 up to 4 T/s, has been developed and manufactured. The use of commercial MN-5 alloy (Cu-5wt.%Ni) and the Cu- 0.5wt.%Mn alloy for matrix of strands are discussed. The critical current density higher than 2700 A/mm2 (5 T, 4.2 K was shown to be attainable

New records of Darevskia armeniaca (Méhely, 1909) and Darevskia valentini (Boettger, 1892) (Squamata, Sauria, Lacertidae) from Armenia and updated geographic distribution maps

During field survey in 2018, we recorded in Armenia the occurrences of the parthenogenetic lizard Darevskia armeniaca and its “paternal” bisexual species D. valentini. Based on our new data and records taken from publications and museums, we update the distribution maps of these species. The new records expand the geographical boundaries of sympatric habitats of these species and provide additional data for understanding the mechanisms of reticulate evolution and hybrid speciation