Results 271 to 280 of about 128,601 (309)

Lifetime of the long-wavelength chlorophyll fluorescence

Biochimica et Biophysica Acta, 1963
The fluorescence lifetime of chlorophyll in vivo and in vitro was measured with a phase fluorimeter. The lifetime in vivo of the long-wavelength emission (730 mμ) which appears at low temperature was 3.1 mμsec. It is concluded that this emission is fluorescence rather than phosphorescence as had been previously reported by Brody.
W L, BUTLER, K H, NORRIS
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Picosecond fluorescent kinetics of in vivo chlorophyll

Biochimica et Biophysica Acta (BBA) - Bioenergetics, 1973
Abstract Fluorescent emission kinetics at 685 nm of in vivo escarole chloroplast chlorophyll has been studied on a picosecond time scale using a frequency-doubled, mode-locked Nd: glass laser (4-ps wide pulses) and an optical Kerr gate. The fluorescent risetime is less than 10 ps and the decay time of the fluorescence envelope is 320 ± 50 ps.
SEIBERT M, ALFANO, Roberto, SHAPIRO SL
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Fluorescence of chlorophyll a in EPA

Chemical Physics Letters, 1976
Abstract New results are reported from the fluorescence spectra of chlorophyll a in EPA. The new spectra are obtained for purer samples than hitherto. Previously reported hot band emission is shown to be due to impurities, and the supposed dimer fluorescence to self-absorption.
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pH control of the chlorophyll a fluorescence in algae

Biochimica et Biophysica Acta (BBA) - Bioenergetics, 1971
Abstract The pH of the suspension medium was found to have a remarkable influence on the “slow” (min) time course of Chlorophyll a fluorescence yield in the green alga Chlorella pyrenoidosa and in the blue-green alga Anacystis nidulans . In Chlorella, the decay of fluorescence yield, in the 1- to 5-min region, is strongly retarded at alkaline pH;
G, Papageorgiou, , Govindjee
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Concentration Quenching of Fluorescence in Chlorophyll Solutions

Nature, 1948
IN a paper concerned chiefly with the results of measurements of the self-quenching of the fluorescence of solutions of aromatic hydrocarbons1, Weiss and Weil-Malherbe report a few measurements on the self-quenching of ethyl chlorophyllide solutions.
W F, WATSON, R, LIVINGSTON
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Intensity effects on the fluorescence of in vivo chlorophyll

Biochimica et Biophysica Acta (BBA) - Bioenergetics, 1977
A technique for measuring relative quantum yields of fluorescence with a picosecond streak camera is described. We show that Chlorella pyrenoidosa exhibit an intensity dependent quantum yield when irradiated with single picosecond light pulses. This effect also occurs under conditions that inhibit the activity of the reaction centres, which can ...
G, Porter, J A, Synowiec, C J, Tredwell
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Chlorophyll Fluorescence: A Probe of Photosynthesis In Vivo

Annual Review of Plant Biology, 2008
The use of chlorophyll fluorescence to monitor photosynthetic performance in algae and plants is now widespread. This review examines how fluorescence parameters can be used to evaluate changes in photosystem II (PSII) photochemistry, linear electron flux, and CO2assimilation in vivo, and outlines the theoretical bases for the use of specific ...
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Stimulated fluorescence and fluorescence quenching in chlorophyll a and bacteriochlorophyll a

Chemical Physics Letters, 1978
Abstract This communication deals with the photophysical processes that take place in chlorophyll solutions under intense nitrogen laser irradiation. The effect of the pump photon density on the fluorescence yield depends strongly on the geometry of the irradiation and the sampling set-up.
J.C. Hindman, R. Kugel, A. Svirmickas, J.J. Katz   +3 more
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Fluorescence anisotropy of chlorophyll a and chlorophyll b in castor oil

Biochimica et Biophysica Acta (BBA) - Bioenergetics, 1989
A detailed study of the fluorescence anisotropy of chlorophyll a and chlorophyll b in castor oil is presented. Scanningacross the wavelength of emission the value of the fluorescence anisotropy shows a considerable variation. This indicates that differently polarized emission moments are present.
M. van Gurp, G. van Ginkel, Y.K. Levine
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Carotenoid-sensitized Fluorescence of Chlorophyll in vitro

Nature, 1958
IT is well established that light absorbed by carotenoids can contribute to photosynthesis, phototaxis and the red fluorescence shown by chlorophyll A in the intact chloroplast. In Chlorella, independent measurements of both fluorescence1 and photosynthesis2 indicate a 40–50 per cent efficiency of energy transfer from β-carotene and lutein to ...
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