A simple quantum-defect model gives analytic expressions for the complex scattering length and threshold collision rates of ultracold molecules. If the probability of reaction in the short-range part of the collision is high, the model gives universal rate constants for s- and p-wave collisions that are independent of short-range dynamics. This model explains the magnitudes of the recently meas...

We have developed a general quenched-flow approach to study platelet function as early as 0.3 seconds after stimulation. Phosphorylation of 20and 40-kd proteins has been analyzed during the first five seconds of platelet response to thrombin from 0.1 to 5.0 U/mi and compared with the progress of aggregation and serotonin secretion. The onset time for aggregation and phosphorylation of both prot...

We present exact results for the spectra of three fermionic atoms in a single well of an optical lattice. For the three lowest hyperfine states of 6Li atoms, we find a Borromean state across the region of the distinct pairwise Feshbach resonances. For 40K atoms, nearby Feshbach resonances are known for two of the pairs, and a bound three-body state develops towards the positive scattering-lengt...

Three magnetic-field induced heteronuclear Feshbach resonances were identified in collisions between bosonic 87Rb and fermionic 40K atoms in their absolute ground states. Strong inelastic loss from an optically trapped mixture was observed at the resonance positions of 492, 512, and 543+/-2 G. The magnetic-field locations of these resonances place a tight constraint on the triplet and singlet c...

Argon analysis on samples of sodalite from Dungannon, Ontario reveals an excess of 36Ar from neutron capture on 35C1 and excess 40Ar from the decay of 40K. These results indicate an average production rate of 5.6 X 102 atoms of 3®C1 per year per gram of chlorine over the age of the mineral. 3 .9X 108 yrs. The surface residence time of chlorine-rich rocks may be determined from the amounts of 36...