Energy-switching

As A4> can amount to several volts, the electron deformation of the adsorbed molecules can be expected to influence their chemical behavior substantially. Therefore, when reactions are catalyzed via the intermediate formation of boundary layers on a catalyst, we may assume that the activation of the reacting molecules is frequently correlated to their polarization on the catalyst surface. There are two effects of polarization either it causes a strong but reversible adsorption, or the deformation of the electron shell of the adsorbed molecule is so thorough that the system—provided that it possesses sufficient activation energy— switches over irreversibly into a new quantized equilibrium position, forming a chemical bond (1) under liberation of energy. Intermediate states exist between these two extremes. 

Wrona, M., Timo, M., Bateman, K. P., Mortishire-Smith, R. J., and O Connor, D. (2005). All-in-one analysis for metabolite identification using liquid chromatography/hybrid quadrupole time-of-flight mass spectrometry with collision energy switching. Rapid... 

Clamp the flask in the ultrasonic bath, at a position of maximum energy. Switch the generator on. The original grey suspension turns to a deep black, heavy mixture. 

M. Wrona, T. Mauriala, K.P. Bateman, R.J. Mortishire-Smith, D. O Coimor, All-in-One analysis for metabolite identification using LC-Q-TOF with collision energy switching. Rapid Commun. Mass Spectrom., 19 (2005)2597. 

Energy-switching methods based on merging forms which are reliable for different energy regimes. 

Fig. 4.19 Carbon in GaAs with carbon doping layers of 8 x lO atoms/cm is profiled with two different beam energies and angles of incidence in a Cameca IMS 3f. By switching polarity of the secondary ions from -4.5 to +4.5 kV with a primary beam voltage of 12.5 kV, the impact energy switches from 17 to 8 keV and the angle from 25° to 39° with significant improvement in depth resolution at the lower impact energy...

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