81 research outputs found
Measurement of the quadratic Zeeman shift of ^{85}Rb hyperfine sublevels using stimulated Raman transitions
We demonstrate a technique for directly measuring the quadratic Zeeman shift
using stimulated Raman transitions.The quadratic Zeeman shift has been measured
yielding [delta][nju] = 1296.8 +/-3.3 Hz/G^{2} for magnetically insensitive
sublevels (5S1/2, F = 2,mF = 0 -> 5S1/2, F = 3,mF = 0) of ^{85}Rb by
compensating the magnetic eld and cancelling the ac Stark shift. We also
measured the cancellation ratio of the differential ac Stark shift due to the
imbalanced Raman beams by using two pairs of Raman beams ([sigma]^{+},
[sigma]^{+}) and it is 1:3.67 when the one-photon detuning is 1.5 GHz in the
experiment
Host pathogen interactions in relation to management of light leaf spot disease (caused by Pyrenopeziza brassicae) on Brassica species
Light leaf spot, caused by Pyrenopeziza brassicae, is currently the most damaging disease problem in oilseed rape in the UK. According to recent survey data, the severity of epidemics has increased progressively across the UK, with current yield losses of up to £160M per annum in England and more severe epidemics in Scotland. Light leaf spot is a polycyclic disease with primary inoculum consisting of air-borne ascospores produced on diseased debris from the previous cropping season. Splash-dispersed conidia produced on diseased leaves are the main component of the secondary inoculum. P. brassicae is also able to infect and cause considerable yield losses on vegetable brassicas, especially Brussels sprouts. There may be spread of light leaf spot among different brassica species. Since they have a wide host range, Pyrenopeziza brassicae populations are likely to have considerable genetic diversity and there is evidence suggesting population variations between different regions, which need further study. Available disease-management tools are not sufficient to provide adequate control of the disease. There is a need to identify new sources of resistance, which can be integrated with fungicide applications to achieve sustainable management of light leaf spot. Several major resistance genes and quantitative trait loci have been identified in previous studies, but rapid improvements in the understanding of molecular mechanisms underpinning B. napus – P. brassicae interactions can be expected through exploitation of novel genetic and genomic information for brassicas and extracellular fungal pathogens.Peer reviewe
Measurement of theg j -factor of the5 D 4-ground state of Fe56 with the atomic beam magnetic resonance method
Measurement of the nuclear magnetic dipole moment of Au197 and hyperfine structure measurements in the ground states of Au197, Ag107, Ag109 and K39
Messung der Zeeman-g J -Faktoren der beiden Yttrium-Grundzust�nde2 D 3/2 und2 D 5/2 mit der Atomstrahlresonanzmethode
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