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The paper presents the history of discovery and distribution of Iris aphilla L., listed in the Red Book of the Russian Federation (status 2 category) in the Batyrevsky area of the State Nature Reserve «Prisursky». It has been reported that the steppe biogeocoenosis, which was severely beaten out by cattle, is being reanimated and restored after 3–5 years after the establishment of the reserve regime. The results of phenological observations of the beginning of blooming of I. aphilla L. from 2004 to the present time ( n = 17) are summarized. According to observations from 2004 to 2020, the early dates of the blooming phase of I. aphilla L. in the Batyrevsky population were noted in 2009, 2010, 2016 (May 14), 2019 (May 12), 2020 (May 10), and later in 2017 (May 23), 2011 (May 26), 2004 (May 28). The average date when the phenophase blooms is on May 17–18 (or ≈56–59 days from the vernal equinox). The influence of abnormally cold weather in the pre-winter period 2009–2010 on the population of I. aphilla L. has been analyzed. The results of this analysis suggest that the ecological scale of D.N. Tsyganov for this species should be extended by the parameter of cryothermal resistance from Cr 7–12 to Cr 1–12 for the northernmost Batyrevskaya population of the specified iris.

Relevance.The widespread use of chlorine-containing polymer materials in the modern world is due to their various advantages over natural analogues. Given the continuing large number of fires, there is still a high risk of exposure to pyrolysis products of chlorine-containing polymer materials, primarily hydrogen chloride and carbon monoxide on the victims. The complexity of determining the toxic effect of pyrolysis products of chlorine-containing polymers makes it necessary to conduct toxicological experimental studies. Intention.The goal is to evaluate the structural and functional disorders of the respiratory system in laboratory animals when intoxicated by pyrolysis products of chlorine-containing polymer materials. Methodology.In an experimental study, pyrolysis of chlorine-containing polymer materials was performed. Thestudy was performed on 96 male rats, in which vital function indicators, pulmonary coefficient, parameters of oxygenation and acid-base state of arterial blood were determined, and histological examination of tracheal and lung tissues was performed. Results and Discussion.It was found that the pyrolysis of chlorinated paraffin (CP-70) with a mass of 7 g and sawdust with a mass of 3 g produces thermal degradation products containing hydrogen chloride at a concentration of 7325 ppm and carbon monoxide at a concentration of 1000 ppm. Exposure to pyrolysis products in laboratory animals resulted in a pronounced irritant effect during intoxication and in the early post-intoxication period. Microscopic examination of lung tissue 48 hours after exposure showed histological signs of interstitial phase of toxic pulmonary edema. We found a decrease in vital functions (heart rate, respiratory rate, rectal temperature) 24, 48 and 72 hours after exposure. Exposure to pyrolysis products led to a violation of gas exchange through the alveolar-capillary membrane, which was confirmed by a decrease in the index of oxygenation and saturation. Violation of the integrity of the alveolar-capillary membrane contributed to the penetration of fluid into the interstitial and alveolar space and the development of toxic pulmonary edema. An increase in the pulmonary coefficient (p 0.05) was observed, after 24 and 48 hours, respectively. Conclusion.As a result of the study, toxic pulmonary edema was simulated in laboratory animals by inhalation of pyrolysis products of chlorine-containing polymer materials, and structural and functional disorders of the respiratory system were determined. It was found that intoxication with pyrolysis products of chlorine-containing materials led to the development of inflammatory changes in the trachea and the manifestation of interstitial pulmonary edema. These changes were accompanied by the development of bradycardia, bradypnea, a decrease in body temperature, as well as an increase (p 0.05) in the pulmonary coefficient, and the development of decompensated respiratory acidosis. The obtained results indicate that the formation of a toxic effect when exposed to pyrolysis products is due to the combined action of hydrogen chloride and carbon monoxide.

Information on the characteristics of the growth and development of plants of large snapdragon, hybrid petunia, sparkling sage, elegant zinnia, depending on the depth of planting is provided. Characteristics of the main morphological signs are given, data on the height of plants, the number of lateral axes, buds, flowers, fruits, leaves, weight and number of roots of deeply planted and control plants are presented; provides information on vegetation periods; ways to improve the agricultural technology of transplants of indicated plants are identified. It is shown that deep planting is an economically viable rational agricultural method that helps to increase the decorativeness of plants, their earlier, long and plentiful flowering, and to improve the aesthetic expressiveness of flower beds without additional labor and material costs.

В статье проанализирован ресурсный потенциал зайцев-беляков в Чувашии с 90-х годов ХХ века по настоящее время. Их популяция находится в депрессивном состоянии, хотя для этого много положительных факторов.

В работе отмечается, что в Чебоксарском филиале Главного ботанического сада РАН выполняются комплексные научные исследования по интродукции новых ценных видов растений из различных флор мира. Созданы уникальные для региона коллекции живых растений. Коллекционные и экспозиционные посадки служат базой для образовательной и эколого-просветительской деятельности: проведения учебных и практических занятий со студентами, организации кружковой работы со школьниками и экскурсионной работы с населением.

GaN/AlGaN high electron mobility transistors (HEMTs) were fabricated on layer structures grown by metal organic chemical vapor deposition on hydride vapor phase epitaxy grown AlN epi-layers on 6H–SiC substrates. The presence of the AlN provides an insulating buffer for effective inter-device isolation, producing isolation currents in the 10−9 A range. These initial HEMTs exhibit saturated drain source current of >400 mA/mm with maximum transconductance of >70 mS/mm. The devices show lower degrees of current collapse relative to more conventional HEMTs fabricated on sapphire substrates, suggesting that the lower defect density is beneficial in reducing surface state trap concentration.

The possibility of using physicomechanical methods of strengthening fissured rock around mine workings subjected to dynamic loads is demonstrated on the basis of calculations performed by the finite-element method. The range of effective utilization of these methods is determined, and quantitative data on the extent of improvement of the stability of the around-the-working rock mass, the cracks of which are filled with a viscous polymeric composition, are presented.