1,721,238 research outputs found
Radial-velocity measurements of subdwarf B stars
Full text linkSubdwarf B (sdB) stars are hot, subluminous stars which are thought to be core-helium burning with thin hydrogen envelopes. The mechanism by which these stars lose their envelopes has been controversial, but it has been argued that binary star interaction is the main cause. Over the past decade we have conducted a radial-velocity study of a large sample of sdB stars, and have shown that a significant fraction of the field sdB population exists in binary systems. In 2002 and 2003, we published 23 new binary sdB stars and the definitions of their orbits. Here, we present the continuation of this project. We give the binary parameters for 28 systems, 18 of which are new. We also present our radial-velocity measurements of a further 108 sdBs. Of these, 88 show no significant evidence of orbital motion. The remaining 20 do show radial-velocity variations, and so are good candidates for further study. Based on these results, our best estimate for the binary fraction in the sdB population is 46-56 per cent. This is a lower bound since the radial-velocity variations of very long period systems would be difficult to detect over the baseline of our programme, and for some sources we have only a small number of measurements
CARBON-DIOXIDE GAS-EXCHANGE AND THE ENERGY STATUS OF LEAVES OF PRIMULA-PALINURI UNDER WATER-STRESS
No full textDietz K-J, Heber U. CARBON-DIOXIDE GAS-EXCHANGE AND THE ENERGY STATUS OF LEAVES OF PRIMULA-PALINURI UNDER WATER-STRESS. Planta. 1983;158(4):349-356
Rate Limiting Factors in Leaf Photosynthesis.1. Carbon Fluxes in the Calvin Cycle
No full textDietz K-J, Heber U. Rate Limiting Factors in Leaf Photosynthesis.1. Carbon Fluxes in the Calvin Cycle. Biochimica et Biophysica Acta. 1984;767(3):432-443
LIGHT AND CO2 LIMITATION OF PHOTOSYNTHESIS AND STATES OF THE REACTIONS REGENERATING RIBULOSE 1,5-BISPHOSPHATE OR REDUCING 3-PHOSPHOGLYCERATE
No full textDietz K-J, HEBER U. LIGHT AND CO2 LIMITATION OF PHOTOSYNTHESIS AND STATES OF THE REACTIONS REGENERATING RIBULOSE 1,5-BISPHOSPHATE OR REDUCING 3-PHOSPHOGLYCERATE. Biochimica et Biophysica Acta. 1986;848(3):392-401
Rate Limiting Factors in Leaf Photosynthesis. 2. Electron-Transport
No full textDietz K-J, Neimanis S, Heber U. Rate Limiting Factors in Leaf Photosynthesis. 2. Electron-Transport. Biochimica et Biophysica Acta. 1984;767(3):444-450
Assimilatory force and regulation of photosynthetic carbon reduction in leaves
No full textDietz K-J, Heber U. Assimilatory force and regulation of photosynthetic carbon reduction in leaves. In: Barber J, ed. Techniques and New Developments in Photosynthesis, NATO ASI Series. New York: Plenum Pr.; 1989: 341-363
THE RELATIONSHIP BETWEEN THE REDOX STATE OF QA AND PHOTOSYNTHESIS IN LEAVES AT VARIOUS CARBON-DIOXIDE, OXYGEN AND LIGHT REGIMES
No full textDietz K-J, SCHREIBER U, HEBER U. THE RELATIONSHIP BETWEEN THE REDOX STATE OF QA AND PHOTOSYNTHESIS IN LEAVES AT VARIOUS CARBON-DIOXIDE, OXYGEN AND LIGHT REGIMES. Planta. 1985;166(2):219-226
FRACTIONAL CONTROL OF PHOTOSYNTHESIS BY THE QB-PROTEIN, THE CYTOCHROME-F CYTOCHROME-B6 COMPLEX AND OTHER COMPONENTS OF THE PHOTOSYNTHETIC APPARATUS
No full textHEBER U, NEIMANIS S, Dietz K-J. FRACTIONAL CONTROL OF PHOTOSYNTHESIS BY THE QB-PROTEIN, THE CYTOCHROME-F CYTOCHROME-B6 COMPLEX AND OTHER COMPONENTS OF THE PHOTOSYNTHETIC APPARATUS. Planta. 1988;173(2):267-274
Pool sizes of Calvin cycle intermediates in chloroplasts as related to limitations of photosynthesis in leaves
No full textDietz K-J, Heber U. Pool sizes of Calvin cycle intermediates in chloroplasts as related to limitations of photosynthesis in leaves. In: Sybesma C, ed. Advances in Photosynthesis Research. Advances in Photosynthesis Research. Vol 3. The Hague: Nijhoff; 1984: 585-588
ASSIMILATORY POWER AS A DRIVING FORCE IN PHOTOSYNTHESIS
No full textHEBER U, NEIMANIS S, Dietz K-J, VIIL J. ASSIMILATORY POWER AS A DRIVING FORCE IN PHOTOSYNTHESIS. Biochimica et Biophysica Acta. 1986;852(1):144-155
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