381 research outputs found
Age characteristics of changes in invertase activity of the mucous membrane of the small intestine
Rats of varying ages were subjected to stress from heat, cold, and hydrocortisone injection. Invertase activity in homogenates of small intestine mucous membranes was studied following sacrifice. Invertase activity was low in young animals, but increased sharply in 30 day old ones, remaining at a relatively constant level until old age. The study concludes that the stress hormone (corticosteroids, etc.) levels in the blood, which affects the formation of enteric enzyme levels and activities, and that age related peculiarities in invertase activity are a consequence of altered hormone status and epitheliocyte sensitivity
Магматические и постмагматические минеральные ассоциации пород массива Малютка (худолазовский комплекс Южного Урала)
Проведены детальные минералогические исследования пород массива Малютка худолазовского дифференцированного комплекса. Выполнено описание морфологии и химического состава многих породообразующих и акцессорных минералов. По результатам исследований выделены магматический и постмагматический (гидротермально-метасоматический) этапы формирования пород. Обсуждаются проблемы, связанные с генетической интерпретацией ряда породообразующих и рудных минералов. Сделан вывод о полигенной природе формирования шпинелидов. Выполнена оценка температуры равновесия в системе «Ti-магнетит–ильменит» (633–650°C), а также температуры кристаллизации хлорита, замещающего флогопит и роговую обманку (145–185°C)
Постостроводужный интрузивный магматизм Западно-Магнитогорской зоны Южного Урала
It is shown that post-island-arc intrusive magmatism of the West-Magnitogorsk Zone embraced the time from Late Devonian to Late Carbon. The new systematization scheme for all variety of intrusive formations is proposed based on the new geological-geochemical data and evolutionary-genetic reconstructions. It presents four discrete intrusive series: 1) gabbro-norite-diorite, 2) gabbro-diorite-granite, 3) peridotite-gabbro-diorite-granite, 4) lamprophyre-dolerite. Each series is characterized by original properties of the body’s morphology and rocks petrography, mineralogy and geochemistry.Показано, что постостроводужный интрузивный магматизм Западно-Магнитогорской зоны охватил интервал времени от позднего девона до позднего карбона. На основе новых геолого-минеральногеохимических данных и эволюционно-генетических реконструкций предложена новая схема систематизации всего многообразия магматитов в виде четырёх дискретных интрузивных серий: 1) габбро-норитдиоритовой, 2) габбро-диорит-гранитовой, 3) перидотит-габбро-диорит-гранитовой, 4) лампрофирдолеритовой. Каждая серия характеризуется особенностями морфологии тел, а также петрографии, минералогии и геохимии пород
Analysis of the impact of informative heat treatment parameters on the properties of hardening of the surface layers
© Published under licence by IOP Publishing Ltd.The change features of surface steel layer were investigated under influence of plasma source of concentrated energy. The results of research of the effect of plasma treatment process on the microstructure and the thickness distribution of microhardness of the product and the formation of heat affected zone were presented. The resulting information (informative) data and measured values of microhardness in the hardened layers, depending on the plasma processing modes allow you to manage the process of heat treatment of metals. Designed programming model that works on the basis of the solution of the heat equation, allows to predict and investigate the temperature field after exposure to the plasma stream
Microwave response near zero magnetic field in transition-metal-doped silicate glasses
A sharp microwave response centered at zero magnetic field was observed in manganese- and iron-doped Na2O-CaO-MgO-SiO2 glasses with phase opposite to the normal Mn+2 and Fe+3 paramagnetic signals. The response can be described as magneto-induced microwave conductivity in the dielectric glass that derives from spin-dependent charge migration within the first coordination sphere of the paramagnetic ion. In contrast to the spin-polarized tunneling in ferromagnets between different valence states of metals, the observed effect is due to spin-dependent tunneling that occurs in the vicinity of manganese or iron in diluted paramagnetic systems
Calcined Low-grade Clays as Sources for Zeolite Containing Material
The continuous development and expansion of a raw material base in response to increasing environmental and technical requirements for most consumable commodities are crucial for the sustainable development of resource- and energy-intensive materials and technologies. As the sources for alkali-activated cements and zeolites, recent studies have reported the suitability of applying calcined clays with various chemical compositions, percentages, and constituent clay minerals and secondary minerals. In this article, the results of a feasibility study on the alkali activation of low-grade clays with 7.26 % montmorillonite/chlorite and 23.14 % kaolinite/montmorillonite minerals are reported. The 6M NaOH activation of clays thermally treated at 700 °C results in the formation of a hardened paste with a compressive strength of up to 5 MPa, with an N-(A)-S-H binder gel and zeolite Na2Al2Si2.5O9∙6.2H2O being the main reaction products
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