The paper follows from the theory of explosion and interaction of an impact wave formed by the explosion and a structure..As a rule, a number of simplifying assumptions must be applied as regards the characteristics of the explosion and of the threatened structure to analyze the structure. As example of dynamic analysis of a new reinforced concrete structure, loaded with a blast wave was used to apply the principles of simpflified ingineering analysis of an explosion-loaded structure. The way of structure failure was analyzed based on time courses of calculated internal forces and displacenets of individual structure elements. The criteria of structural elements failure due to explosion load effects were determined as a part of the dynamic structure response assessment. and Obsahuje seznam literatury
Photosynthesis, photorespiration, and chlorophyll (Chl) fluorescence in green and red Berberis thunbergii leaves were studied with two different measuring radiations, red (RR) and "white" (WR). The photosynthetic and photorespiration rates responded differently to the different radiation qualities, which indicate that the carboxylase and oxygenase activities of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) were affected. Differences in photosynthetic rate between the two color leaves were less under RR than under WR. However, this reduced difference in photosynthetic rate was not correlated with the stomatal response to the measuring radiation qualities. Compared with the WR, the RR reduced the differences in dark-adapted minimum and maximum fluorescence, steady-state fluorescence, light-adapted maximum fluorescence, and actual photochemical efficiency (ΦPS2) of photosystem 2 (PS2), but enlarged the difference in non-photochemical quenching between the two color leaves. Differences in both maximum quantum yield of PS2 and ratio of ΦPS2 to quantum yield of CO2 fixation between the two color leaves were similar under the two measuring radiations. To exclude disturbance of radiation attenuation caused by anthocyanins, it is better to use RR to compare the photosynthesis and Chl fluorescence in green versus red leaves. and P.-M. Li ... [et al.].
Light-induced Ca2+ concentration oscillations in cytoplasm of oat protoplasts were shown to be controlled by inhibitors of Ca^"*" pumps, sodium vanadate and tuBHQ. The sources of Ca^'*' released into cytoplasm under the action of radiant energy are vacuole and endoplasmic reticulum, but not mitochondria. The manifestation of Ca^'*' oscillations depends on the concentrations of oat protoplasts in the suspension which suggests the propagation of a signál between the cells and synchronization of their light-induced Ca2+ oscillation response.
The nuclear fusion processes that power the Sun take place at such high temperatures that the nuclei of atoms are able to fuse together, a process that results in the creation of very large numbers of fundamental particles called neutrinos. Neutrinos only interact through the weak interaction and gravity and therefore can penetrate out from the core of the Sun and through the Earth with little or no interaction. It is these neutrinos from the Sun that are the subject of our measurements with the Sudbury Neutrino Observatory (SNO), 2 km underground in a mine near Sudbury, Canada. With the use of heavy water as a central element in the design of SNO it was possible to determine clearly that electron neutrinos change to one of the other active flavors before reaching our detector, a property that requires that they have a mass greater than zero. Both of these fundamental neutrino properties are beyond the predictions of the Standard Model for elementary particles. Extensions of the Standard Model to include these neutrino properties can give us a more complete understanding of our Universe at a very basic level., Arthur B. McDonald ; přeložil Ivan Gregora., and Obsahuje bibliografii