The areal development of photosynthetic efficiency and growth patterns in expanding leaves of two different dicotyledonous species - Coccoloba uvifera and Sanchezia nobilis - was investigated by imaging both processes repeatedly over 32 days. Measurements were performed using combined imaging systems for chlorophyll fluorescence and growth, with the same spatial resolution. Significant differen...

We examined the photosynthetic responses of four species of saplings growing in the understory of the Duke Forest FACE experiment during the seventh year of exposure to elevated CO2 concentration ([CO2]). Saplings of these same species were measured in the first year of the Duke Forest FACE experiment and at that time showed only seasonal fluctuations in acclimation of photosynthesis to elevate...

Intermolecular electron-transfer reactions have a crucial role in biology, solution chemistry and electrochemistry. The first step of such reactions is the expulsion of the electron to the solvent, whose mechanism is determined by the structure and dynamical response of the latter. Here we visualize the electron transfer to water using ultrafast fluorescence spectroscopy with polychromatic dete...

the dye-sensitized solar cells (dssc) have been regarded as one of the most promising new generation solar cells. tremendous research efforts have been invested to improve the efficiency of solar energy conversion which is generally determined by the light harvesting efficiency, electron injection efficiency and undesirable electron lifetime. in this review, various characteristics of dye-sensi...

The most photosynthetically active leaves of rice seedlings were severely damaged when shoots but not roots were chilled (10°C/25°C, respectively), but no such injury was observed when the whole seedling was chilled (10°C/10°C). To elucidate the mechanisms, we compared the photosynthetic characteristics of the seedlings during the dark chilling treatments. Simultaneous analyses of Chl fluoresce...

in this paper, we examine the effect of the energy difference between the l- and the -valleys in compound semiconductor materials, carrier effective mass, and the scattering processes on the electron transport characteristics in mesfets. to do this, we use the monte carlo simulation to demonstrate the superiority of the ingaas mesfet, made on a semi-insulating inp substrate, over both inp and ...

The effects of drought on Photosystem II (PSII) fluorescence and photosynthetic electron transport activities were analyzed in cotton. Water stress did not modify the amplitude of leaf variable fluorescence at room temperature in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) nor at 77 K. It is therefore concluded that photon collection, their distribution between the two photos...

Photoreduction of the artificial electron acceptor, cytochrome c, by isolated spinach chloroplasts in the absence of added catalyst has been found to be resistant to inhibition by 10 mM salicyl­ aldoxime. This contrasts with the pronounced inhibition of the photoreduction of both 2,6-dichlorophenolindophenol and ferricyanide over a range of electron flow rates, and indicates an inhibition on th...

Disulfiram (tetraethylthiuram disulfide), a metal chelator, inhibits photosynthetic electron transport in broken chloroplasts. A major site of inhibition is detected on the electron-acceptor side of photosystem II between Q(A), the first plastoquinone electron-acceptor, and the second plastoquinone electron-acceptor, Q(B). This site of inhibition is shown by a severalfold increase in the half-t...

The effect of sodium chloride on the photosynthetic electron transport chain was investigated in the freshwater green alga Chlorella vulgaris. It was found that the rate of oxygen evolution under steady state and flash light conditions diminished by increasing salt concentrations. Salt treatment of cells also decreased the fluorescence and delayed luminescence yields. However, the fluorescence ...