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2. Determinant of photosynthetic capacity in rice leaves under ambient air conditions

Creator:
Zhang, D.-Y., Wang, X.-H., Chen, Y., and Xu, D.-Q.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
carboxylation efficiency, flag leaf, intercellular CO2 concentration, leaf position, net photosynthetic rate, Oryza, and stomatal conductance
Language:
Multiple languages
Description:
At the grain-filling stage, net photosynthetic rate (PN), stomatal conductance (gs), and ribulose-1,5-bisphosphate carboxylation efficiency (CE) were correlated in order to find the determinant of photosynthetic capacity in rice leaves. For a flag leaf, PN in leaf middle region was higher than in its upper region, and leaf basal region had the lowest PN value. The differences in gs and CE were similar. PN, gs, and CE gradually declined from upper to basal leaves, showing a leaf position gradient. The correlation coefficient between PN and CE was much higher than that between PN and gs in both cases, and PN was negatively correlated with intercellular CO2 concentration (Ci). Hence the carboxylation activity or activated amount of ribulose-1,5-bisphosphate carboxylase/oxygenase rather than gs was the determinant of the photosynthetic capacity in rice leaves. In addition, in flag leaves of different tillers PN was positively correlated with gs, but negatively correlated with Ci. Thus gs is not the determinant of the photosynthetic capacity in rice leaves. and D.-Y. Zhang ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Spectral investigation of eclipsing binary stars at the stage of mass exchange

Creator:
Karetnikov, V. G.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
spectral investigation, eclipsing binary stars, and mass exchange
Language:
Czech
Description:
From spectrograms with dispersion 9-37 A/mm the spectral characteristics of eight eclipsing binary stars have been studied shov/ing the effects of mass exchange. Spectral types of stars have been deterrained as well as temperatures of excitation, parameters of damping, turbulent velocities, electron number densities, Chemical composition of stellar atmospheres and displacements of lines in radiation and absorption, variations in characteristics of lines, as the function of phase. It is shown that appreciable differences of physical conditions frorn normal ones háae not been observed. Schemes-models of studied stellar systems have been presented and discussed.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public