太阳能屋顶光伏发电系统设计及效益分析

太阳能发电可分为光发电和热发电两种,其中光发电是不通过热转换直接将太阳光转换成电的方式,也称为光伏发电。太阳能光伏发电是新能源利用的重要领域。文中基于实例分析了屋顶光伏发电系统的大量实际数据,表明了太阳能屋顶光伏发电系统具有良好的社会、经济效益和广阔的发展前景,为今后屋顶光伏发电系统设计和推广提供参考依据。     

Measurement of the total reaction cross section for the mirror nuclei ~(12)N and ~(12)B

The mirror nuclei 12N and 12B are separated by the Radioactive Ion Beam Line in Lanzhou(RIBLL) at HIRFL from the breakup of 78.6 MeV/u 14N on a Be target.The total reaction cross-sections of 12N at 34.9 MeV/u and 12B at 54.4 MeV/u on a Si target have been measured by using the transmission method.Assuming 12N consists of a 11C core plus one halo proton,the excitation function of 12N and 12B on a Si target and a C target were calculated with the Glauber model.It can fit the experimental data very well.The ch...     

Solvent effects and potential of mean force study of the S_N2 reaction of CH_3F+CN~- in water

We used a combined quantum mechanics and molecular mechanics(QM/MM) method to investigate the solvent effects and potential of mean force of the CH_3F+CN~- reaction in water. Comparing to gas phase, the water solution substantially affects the structures of the stationary points along the reaction path. We quantitatively obtained the solvent effects' contributions to the reaction: 1.7 kcal/mol to the activation barrier and -26.0 kcal/mol to the reaction free energy.The potential mean of force calculated with the density functional theory/MM theory has a barrier height at 19.7 kcal/mol,consistent with the experimental result at 23.0 kcal/mol; the calculated reaction free energy at -43.5 kcal/mol is also consistent with the one estimated based on the gas-phase data at -39.7 kcal/mol.