+
 Homogeneous Catalysis in Supercritical Fluids
Supercritical fluids, compounds heated and pressurized beyond the critical 
point, have many unusual properties. Homogeneous molecular catalysis, which 
have far greater control over selectivity than heterogeneous solid catalysts, 
are now being tested in SCFs., and early results show that high rates, improved
selectivity, and elimination of mass-transfer problems can be achieved.  As 
industry moves away from toxic or environmentally damaging solvents, 
supercritical carbon dioxide may be an ideal replacement medium for nonpolar 
or weakly polar chemical processes.  More than simply substitutes for nonpolar 
solvents, SCFs can radically change the observed chemistry. Supercritical 
carbon dioxide is also an excellent medium for its own fixation, as 
demonstrated by studies of its hydrogenation.





 
+
 Scanning Interferometric Apertureless Microscopy:Optical Imaging at 
10Angstrom Resolution
Interferometric near-field optical microscopy achieving a resolution of 10 
angstroms is demonstrated.  The scattered electric field variation caused 
by a vibrating probe tip in close proximity to a sample surface is measured by 
encoding it as a modulation in the optical phase of one arm of an 
interferometer.  Unlike in regular near-field optical microscopes, where the 
contrast results from a weak source (or aperture) dipole interacting with the 
polarizability of the same, the present form of imaging relies on a 
fundamentally different contrast mechanism:sensing the dipole-dipole coupling 
of two externally driven dipoles (the tip and sample dipoles) as their spacing 
is modulated.



 
+
 Sprites, ELF transients, and positive ground strokes  
In two summertime mesoscale convective systems (MCSs), mesospheric optical 
sprite phenomena were often coincident with both large-amplitude positive cloud-
to-ground lightning and transient Schumann resonance excitations of the entire 
Earth-ionosphere cavity.  These observations, together with earlier studies of 
MCS electrification, suggest that sprites are triggered when the rapid removal 
of large quantities of positive charge from an areally extensive charge layer 
stresses the mesosphere to dielectric breakdown


--fin