Particle-exchange heat engine working between bosonic and fermionic reservoirs.

We propose a mesoscopic particle-exchange heat engine realized via coupled quantum dots. The engine is able to extract work from a bosonic reservoir and can be used as a refrigerator. The electric current is derived from a master-equation method and is readdressed under a thermodynamic context.

Threshold collision-induced dissociation of hydrogen-bonded dimers of carboxylic acids.

Energy-resolved competitive collision-induced dissociation is used to investigate the proton-bound heterodimer anions of a series of carboxylic acids (formic, acetic, and benzoic acid) and nitrous acid with their conjugate bases. The dissociation reactions of the complexes [CH3COO.H.

Threshold behavior in electron-transfer collisions between rubidium atoms and C2F5Cl or C2F5I molecules.

Rubidium atoms are accelerated in a high-temperature expansion of hydrogen to produce beams with energies high enough to observe collisional ionization with a cross beam. The speed of the atoms is directly measured by time-of-flight techniques, and the positive and negative ions produced are detected in separate mass spectrometers and detected in coincidence. Chloroperfluoroethane produces C(2)F(5)(-) and Cl(-) ions, whereas iodoperfluoroethane produces I(-), C(2)F(5)(-), and C(2)F(5)I(-) ions.

Evidence for orbital-specific electron transfer to oriented haloform molecules.

Beams of hyperthermal K atoms cross beams of the oriented haloforms CF(3)H, CCl(3)H, and CBr(3)H, and transfer of an electron mainly produces K(+) and the X(-) halide ion which are detected in coincidence. As expected, the steric asymmetry of CCl(3)H and CBr(3)H is very small and the halogen end is more reactive. However, even though there are three potentially reactive centers on each molecule, the F(-) ion yield in CF(3)H is strongly dependent on orientation.