Six low-lying tautomers of 1-methyl-hypoxanthine have been studied at the B3LYP/aug-cc- pVDZ level. Two tautomers NTH and N9H with the comparable energies are far more stable than the others. The vertical ionization e...Six low-lying tautomers of 1-methyl-hypoxanthine have been studied at the B3LYP/aug-cc- pVDZ level. Two tautomers NTH and N9H with the comparable energies are far more stable than the others. The vertical ionization energies of the tautomers calculated with ab initio electron propagator theory in the P3/aug-cc-pVDZ approximation are in agreement with the experimental data from photoelectron spectroscopy. According to the calculated relative energies and the comparison between the simulated and the experimental photoelectron spectra, it demonstrates that there are at least two tautomers of 1-methyl-hypoxanthine in the gas-phase experiments.展开更多
In this paper,we consider a cognitive radio system with energy harvesting,in which the secondary user operates in a saving-sensing-transmitting(SST) fashion.We investigate the tradeoff between energy harvesting,channe...In this paper,we consider a cognitive radio system with energy harvesting,in which the secondary user operates in a saving-sensing-transmitting(SST) fashion.We investigate the tradeoff between energy harvesting,channel sensing and data transmission and focus on the optimal SST structure to maximize the SU's expected achievable throughput.We consider imperfect knowledge of energy harvesting rate,which cannot be exactly known and only its statistical information is available.By formulating the problem of expected achievable throughput optimization as a mixed-integer non-linear programming one,we derive the optimal saveratio and number of sensed channels with indepth analysis.Simulation results show that the optimal SST structure outperforms random one and performance gain can be enhanced by increasing the SU's energy harvesting rate.展开更多
文摘Six low-lying tautomers of 1-methyl-hypoxanthine have been studied at the B3LYP/aug-cc- pVDZ level. Two tautomers NTH and N9H with the comparable energies are far more stable than the others. The vertical ionization energies of the tautomers calculated with ab initio electron propagator theory in the P3/aug-cc-pVDZ approximation are in agreement with the experimental data from photoelectron spectroscopy. According to the calculated relative energies and the comparison between the simulated and the experimental photoelectron spectra, it demonstrates that there are at least two tautomers of 1-methyl-hypoxanthine in the gas-phase experiments.
基金supported by National Nature Science Foundation of China(NO.61372109)
文摘In this paper,we consider a cognitive radio system with energy harvesting,in which the secondary user operates in a saving-sensing-transmitting(SST) fashion.We investigate the tradeoff between energy harvesting,channel sensing and data transmission and focus on the optimal SST structure to maximize the SU's expected achievable throughput.We consider imperfect knowledge of energy harvesting rate,which cannot be exactly known and only its statistical information is available.By formulating the problem of expected achievable throughput optimization as a mixed-integer non-linear programming one,we derive the optimal saveratio and number of sensed channels with indepth analysis.Simulation results show that the optimal SST structure outperforms random one and performance gain can be enhanced by increasing the SU's energy harvesting rate.