The reaction of ClONO2 with H2O on various water clusters has been investigated via an ab initio calculation at the MP2//HF/6-31G(d) level. The calculations have shown that as more water molecules are involved in the reaction, the barrier height drops dramatically. The barrier energies of the reaction on the water clusters vary with the extent of hydration. A value as low as 3.2 kcal/mol was observed in the calculation. It is suggested that the ice surface shows catalytic character for the heterogeneous reaction through structure catalysis and hydration. It is shown that our mechanism of ClONO2 hydrolysis on ice surfaces is in a broad sense compatible with the ion-catalyzed mechanism.

Direct ab initio dynamics calculations for rates and the kinetic isotope effects of multiproton transfer in ClONO 2 + HCl → HNO 3 + Cl 2 reactions with water clusters: Breakdown of the rule of the geometric mean

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In this article, the trajectories of S -deoxyephedrine (SBD) along molecular channels within the complex protein structure of third dopamine receptor (D 3 R) are analyzed via molecular dynamic techniques, including potential mean force calculations of umbrella samplings from the 4.5 version of the GROMACS program. Changes in free energy due to the movement of SBD within D 3 R are determined, and the molecular dynamic mechanisms of SBD transmitting along molecular channels are probed. Molecular simulated results show that the change in free energy is calculated as 171.7 kJ·mol –1 for the transmission of SBD toward the outside of the cell along the y + axis functional molecular channel and is 275.0 kJ·mol –1 for movement toward the intracellular structure along the y – axis. Within the internal structure of D 3 R, the changes in free energy are determined to be 103.6, 242.1, 459.7, and 127.8 kJ·mol –1 for transmission of SBD along the x +, x –, z +, and z – axes, respectively, toward the cell bilayer membrane, which indicates that SBD leaves much more easily along the x + axis through the gap between the TM5 (the fifth transmembrane helix) and TM6 (the sixth transmembrane helix) from the internal structure of D 3 R. The values of free-energy changes indicate that SBD molecules can clear the protective channel within D 3 R, which helps dopamine molecules to leave the D 3 R internal structure along the x + axis and to prevent them for exerting excessive neurotransmitter function. Therefore, our results suggest that SBD is effective for development as a drug for treating schizophrenia and its pharmacology is closely related to its dynamics and mechanisms within the molecular pathway of dopamine receptors.

Operating temperature and thermal uniformity have great effect on the performance, cycle life and safety of lithium-ion power batteries. In order to investigate the surface temperature change and distribution of a large-capacity and rectangular LiFePO4/C power battery, this paper conducts experiments on charging and discharging a battery module and cell at different current rates and various ambient temperatures. Results of thermalcouple-measurement show that temperature rising rates at different temperatures during charge and discharge change in accordance with the variation tendency of the resistance at different state of charge (SOC) and oprating temperatures. Under elevated ambient temperatures, the temperature excurtion and maximum temperature difference of the module are all smaller. Under the same ambient temperature, battery temperature at the end moment of discharge increases and the temperature uniformity of the module deteriorate at higher discharging rate. Temperature excurtion over the same time period is in a relationship of a standard quadratic function with the discharge current. Results of the thermal infrared imaging tests show that the maximum surface temperature differences at different discharging currents of 20A, 40A, and 80A are all above 5°C under natral convection heat transfer. The temperature of the lower part is higher than that of the upper part, while that of the central area is the highest. In a comprehensive charging and discharging scheme, the tendency of maximum surface temperature difference changes in accordance with that of the average surface temperature.