RESUMO
We report the results of an optical-optical double resonance experiment to determine the NaK 3(1)Pi state potential energy curve. In the first step, a narrow band cw dye laser (PUMP) is tuned to line center of a particular 2(A)1Sigma+(v', J') <-- 1(X)1Sigma+(v", J") transition, and its frequency is then fixed. A second narrowband tunable cw Ti:Sapphirelaser (PROBE) is then scanned, while 3(1)Pi --> 1(X)1Sigma+ violet fluorescence is monitored. The Doppler-free signals accurately map the 3(1)Pi(v, J) ro-vibrational energy levels. These energy levels are then fit to a Dunham expansion to provide a set of molecular constants. The Dunham constants, in turn, are used to construct an RKR potential curve. Resolved 3(1)Pi(v, J) --> 1(X)1Sigma+(v", J") fluorescence scans are also recorded with both PUMP and PROBE laser frequencies fixed. Comparison between observed and calculated Franck-Condon factors is used to determine the absolute vibrational numbering of the 3(1)Pi state levels and to determine the variation of the 3(1)Pi --> 1(X)1Sigma+ transitiondipole moment with internuclear separation. The recent theoretical calculation of the NaK 3(1)Pi state potential reported by Magnier and Millié (1996, Phys. Rev. A 54, 204) is in excellent agreement with the present experimental RKR curve. Copyright 1999 Academic Press.
RESUMO
Mushrooms of the subgenus Rubescentes (for example Agaricus bisporus and Agaricus campestris) accumulate for less cadmium than most species of the subgenus Flavescentes (for example Agaricus arvensis and Agaricus silvicola). Hence it appears there is no danger for human health, from too much cadmium, when eating the often gathered Agaricus campestris. The caps of the mushrooms enrich cadmium to twice the amount present in the stems. The authors analysed 32 samples of wild mushrooms of the subgenus Rubescentes and 39 samples of wild mushrooms of the subgenus Flavescentes. They furthermore cultivated mushrooms (Agaricus bisporus) on substrates with different amounts of added cadmium.