Quantum chemical calculations are performed to study the reactions of OH and ozone with- out and with water to estimate whether the single water molecule can decrease the energy barrier of the OH radical reaction with ozone. The calculated results demonstrate that the single water molecule can reduce the activated barrier of the naked OH＋Oa reaction with the value of about 4.18 kJ/mol. In addition, the transition state theory is carried out to determine whether the single water molecule could enhance the rate constant of the OH＋O3 reaction. The computed kinetic data indicate that the rate of the ozone reaction with the formed complexes between OH and water is much slower than that of the OH＋O3 reaction, whereas the rate constant of OH reaction with the formed H20---Oa complex is 2 times greater than that of the naked OH radical with ozone reaction. However, these processes in the atmosphere are not important because the reactions can not compete well with the naked reaction of OH with ozone under atmospheric condition.
By using the transfer matrix,the band structures,defect mode and field propagation characteristics of one-dimensional photonic crystals composed of single-negative (SNG) material are studied. It is shown that this structure possesses a new type of photonic gap which is insensitive to the incident angle and the light polarizations,as well the change of scale length. When a normal dielectric defect layer is inserted,the defect mode is insensitive to the angle of incidence,but the electro-magnetic field in the defect layer is strongly localized,and the number of the defect modes increases with the thickness of the defect layer.
The G3 and CBS-QB3 theoretical methods are employed to study the decomposition of CF3OH into FCFO and HF by water, water dimmer, and ammonia. The decomposition of CF3OH into FCFO and HF is unlikely to occur in the atmosphere due to the high activated energy of 88.7 k J/mol at the G3 level of theory. However, the computed results predict that the barrier for unimolecular decomposition of CF3OH is decreased to 25.1 kJ/mol from 188.7 k J/mol with the aid of NH3 at the G3 level of theory, which shows that the ammonia play a strong catalytic effect on the split of CF3OH. In addition, the calculated rate constants show that the decomposition of CF3OH by NH3 is faster than those of H2O and the water dimmer by 10^9 and 10^5 times respectively. The rate constants combined with the corresponding concentrations of these species demonstrate that the reaction CF3OH with NH3 via TS4 is of great importance for the decomposition of CF3OH in the atmosphere.
