19,006 research outputs found
Magnetic susceptibility of vanadium carbide
Magnetic susceptibility of vanadium carbide from 77 to 300 K measured by magnetomete
Acidification of Minnesota Soils by Nitrogen Fertilization and Acid Rain
The effect of inputs of acidifying nitrogen fertilizer and acid rain on the pH of a typical Minnesota prairie agricultural soil was estimated. Experimental data from a long term continuous corn experiment at the Southwest Experiment Station near Lamberton were used to calculate the effects of nitrogen fertilizers. Acid rain effects were estimated using soil buffering data obtained in the experiment along with existing estimates of rainfall acidity. In a typical corn-soybean rotation, using 100 kg per ha of nitrogen additions to corn, a 0 .25 unit pH drop is expected in about 38 years. The estimated acidity of the rainfall would cause the same pH drop in a minimum of 127 years
Systematic study of Optical Feshbach Resonances in an ideal gas
Using a narrow intercombination line in alkaline earth atoms to mitigate
large inelastic losses, we explore the Optical Feshbach Resonance (OFR) effect
in an ultracold gas of bosonic Sr. A systematic measurement of three
resonances allows precise determinations of the OFR strength and scaling law,
in agreement with coupled-channels theory. Resonant enhancement of the complex
scattering length leads to thermalization mediated by elastic and inelastic
collisions in an otherwise ideal gas. OFR could be used to control atomic
interactions with high spatial and temporal resolution.Comment: Significant changes to text and figure presentation to improve
clarity. Extended supplementary material. 4 pages, 4 figures; includes
supplementary material 8 pages, 4 figures. Submitted to Physical Review
Letter
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