A ring R is (weakly) nil clean provided that every element in R is the sum of a (weak) idempotent and a nilpotent. We characterize nil and weakly nil matrix rings over abelian rings. Let R be abelian, and let n 2 N. We prove that Mn(R) is nil clean if and only if R/J(R) is Boolean and Mn(J(R)) is nil. Furthermore, we prove that R is weakly nil clean if and only if R is periodic; R/J(R) is Z3, B or Z3 B where B is a Boolean ring, and that Mn(R) is weakly nil clean if and only if Mn(R) is nil clean for all n > 2., Nahid Ashrafi, Marjan Sheibani, Huanyin Chen., and Seznam literatury
In this study, cotton seedlings were subjected to osmotic-, salt- and alkali stresses. The growth, photosynthesis, inorganic ions, and organic acids in the stressed seedlings were measured, to compare the mechanisms by which plants adapt to these stresses and attempt to probe the mechanisms by which plants adapt to high pH stress. Our results indicated that, at high stress intensity, both osmotic and alkali stresses showed a stronger injurious effect on growth and photosynthesis than salt stress. Cotton accumulated large amount of Na+ under salt and alkali stresses, but not under osmotic stress. In addition, the reductions of K+, NO3 -, and H2PO4 - under osmotic stress were much greater than those under salt stress with increasing stress intensity. The lack of inorganic ions limited water uptake and was the main reason for the higher injury from osmotic-compared to salt stress on cotton. Compared with salt- and alkali stresses, the most dramatic response to osmotic stress was the accumulation of soluble sugars as the main organic osmolytes. In addition, we found that organic acid metabolism adjustment may play different roles under different types of stress. Under alkali stress, organic acids might play an important role in maintaining ion balance of cotton; however, under osmotic stress, malate might play an important osmotic role. and W. Chen ... [et al.].
Tento článek představuje stručný vhled do současného stavu dostupných laserových systémů, které v rámci centra HiLASE slouží ke studiu základních i pokročilých aspektů interakce laserového záření s látkou. Výzkum v této oblasti je organizován především v rámci projektu BIATRI ("Pokročilá tvorba funkčních materiálů: Od mono- k BI A TRI-chromatické excitaci s tvarovanými laserovými impulzy") [1]., This article presents a brief introduction to, and the current state of, available laser systems for the study of both fundamental and advanced aspects of laser-matter interaction. The planned research work is mainly organized under the framework of project BIATRI (“Advanced designing of functional materials: From mono- to BI- And TRI-chromatic excitation with tailored laser pulses”). The strategic aim of BIATRI is to explore novel pathways of matter evolution, for designing materials with new unique properties and to find specific conditions for the most efficient coupling of laser light with matter. A key role in BIATRI work packages is hot plasma effects, which create extreme heating conditions, and which are difficult to reach by other means. This can be achieved by finding specific conditions with programmed coupling of laser light with matter. It is planned to use both mono-chromatic light with specific focusing conditions and combinations of two or three laser beams with different wavelengths. The first pulse will generate a free carrier population within the irradiated material enabling the efficient absorption of photons from a second or/and third pulse. Planned research work is also supplementary by the large-scale project HiLASE CoE, providing synergy for the whole scope of lab research work., Nathan Goodfriend, Juraj Sládek, Miroslava Flimelová, Wladimir Marine, Inam Mirza, Nadezhda M. Bulgakova., and Obsahuje bibliografické odkazy
In mesophyll chloroplasts of control plants of grape vine (Vilis vinifera L.) growing in greenhouse, grana consisted of 3-10 thylakoids interconnected by long stroma thylakoids. Chloroplasts in magnesium-deficient plants were characterized by a dense stroma, poorly distinquished fme stroma lamellae, and by an accumulation of large osmiophilic globules. Under iron deficiency, the chloroplasts exerted two types of damage of intemal structure: (7) grana consisted of 2-6 thylakoids, the stroma lamellae were destructed; (2) grana were reduced, the stroma lamel ae were broken into short thick fragments, that were laid successively in the direction along the axis of the chloroplasts.