Factors affecting the synthesis and properties of a new generation of fine particle low voltage phosphors in field emission displays are reviewed. The morphology and particle size, the composition and stoichiometry, the stability, together with the nature and shape of the particle surface, all play important roles in the performance of the final phosphor. Initial new results from novel synthetic methodology are presented and discussed. Their implications in the light of the known literature point the way to the successful conclusion of the current thrust of phosphor research for good red, green, and blue low voltage, high definition phosphors.

to 3000 km wide separated regularly by -6800 km alolipside a dark belt at 50"s that probably pertained to a wave phenomena resulting from the disturbance. T h e u ~norphologic evolution of this disturbance resembled, o n a smaller scale, previous GWS disturba~lces (3), and it was probably a transient convective phenomenon rapidly disnersed bv the zonal winds.This obserl.ation, together with other transient snots ohserl~ed in recent times ( l o ) , suggests that mid-scale storms o n Saturn could be Inore frequent than previously thought. Theii detection is a cluestion of the telnnoral coveraee of the observations. " the techniques used, and the contrast of the features against the background of ~lorlnal clouds.

We perform ab initio molecular-dynamics simulations using the higher-order finite-differencepseudopotential (FDP) method to calculate the interatomic forces. Our approach is compared to moleculardynamics-simulation calculations where the forces are calculated using a plane-wave basis. The ground-state structures of small silicon clusters obtained from the FDP simulation are in excellent agreement with those of the plane-wave method. The FDP method is performed completely in real space, and is easier to implement than methods based on a plane-wave expansion.

The properties of phase escape in a dc superconducting quantum interference device ͑SQUID͒ at 25 mK, which is well below quantum-to-classical crossover temperature T cr , in the presence of strong resonant ac driving have been investigated. The SQUID contains two Nb/ Al-AlO x / Nb tunnel junctions with Josephson inductance much larger than the loop inductance so it can be viewed as a single junction having adjustable critical current. We find that with increasing microwave power W and at certain frequencies and / 2, the single primary peak in the switching current distribution, which is the result of macroscopic quantum tunneling of the phase across the junction, first shifts toward lower bias current I and then a resonant peak develops. These results are explained by quantum resonant phase escape involving single and two photons with microwave-suppressed potential barrier. As W further increases, the primary peak gradually disappears and the resonant peak grows into a single one while shifting further to lower I. At certain W, a second resonant peak appears, which can locate at very low I depending on the value of . Analysis based on the classical equation of motion shows that such resonant peak can arise from the resonant escape of the phase particle with extremely large oscillation amplitude resulting from bifurcation of the nonlinear system. Our experimental result and theoretical analysis demonstrate that at T Ӷ T cr , escape of the phase particle could be dominated by classical process, such as dynamical bifurcation of nonlinear systems under strong ac driving.