Ten 4-substituted bicyclic phosphates were synthesized and their ^(13)C-NMR were also determined.A good relationship was observed between 4-^(13)C chemical shift and Taft σ_X induc- tive paramenters.Substituent effec...Ten 4-substituted bicyclic phosphates were synthesized and their ^(13)C-NMR were also determined.A good relationship was observed between 4-^(13)C chemical shift and Taft σ_X induc- tive paramenters.Substituent effects on ~3J_(P-C) coupling constant were studied.展开更多
Increasing simultaneously both the cutoff energy and efficiency is a big challenge to all applications of high-order harmonic generation(HHG).For this purpose,the shaping of the waveform of driving pulse is an alterna...Increasing simultaneously both the cutoff energy and efficiency is a big challenge to all applications of high-order harmonic generation(HHG).For this purpose,the shaping of the waveform of driving pulse is an alternative approach.Here,we show that the harmonic cutoff can be extended by about two times without reducing harmonic yield after considering macroscopic propagation effects,by adopting a practical way to synthesize two-color fields with fixed energy.Our results,combined with the experimental techniques,show the great potential of HHG as a tabletop light source.展开更多
基金Project Supported by National Sciences Foundation of China.
文摘Ten 4-substituted bicyclic phosphates were synthesized and their ^(13)C-NMR were also determined.A good relationship was observed between 4-^(13)C chemical shift and Taft σ_X induc- tive paramenters.Substituent effects on ~3J_(P-C) coupling constant were studied.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11264036,11164025,11364038the Specialize Research Fund for the Doctoral Program of Higher Education of China under Grant No.20116203120001the Basic Scientific Researc Foundation for Institution of Higher Learning of Gansu Province
文摘Increasing simultaneously both the cutoff energy and efficiency is a big challenge to all applications of high-order harmonic generation(HHG).For this purpose,the shaping of the waveform of driving pulse is an alternative approach.Here,we show that the harmonic cutoff can be extended by about two times without reducing harmonic yield after considering macroscopic propagation effects,by adopting a practical way to synthesize two-color fields with fixed energy.Our results,combined with the experimental techniques,show the great potential of HHG as a tabletop light source.
