The C--C bond dissociation energy （BDE） is a very important data in research of hydrocarbon cracking reactions, because it reflects the difficulty level of chemical reactions. But it is very difficult to obtain the ...The C--C bond dissociation energy （BDE） is a very important data in research of hydrocarbon cracking reactions, because it reflects the difficulty level of chemical reactions. But it is very difficult to obtain the C--C bond dissociation energy （BDE） by experiments, so using quantum chemistry calculation such as density functional theory （DFT） to study the C--C bond dissociation energy is a very useful means. The impact of acceptor substituents and donor substituents on the C--C bond length distribution was studied.展开更多
The pyrolysis of isopsoralen was studied by synchrotron vacuum ultraviolet photoionization mass spectrometry at low pressure. The pyrolysis products were detected at different photon energies, the ratios of products t...The pyrolysis of isopsoralen was studied by synchrotron vacuum ultraviolet photoionization mass spectrometry at low pressure. The pyrolysis products were detected at different photon energies, the ratios of products to precursor were measured at various pyrolysis temperatures. The experimental results demonstrate that the main pyrolysis products are primary CO and sequential CO elimination products （C10H602 and C9H60）. The decomposition channels of isopsoralen were also studied by the density functional theory, then rate constants for competing pathways were calculated by the transition state theory. The dominant decom- position channels of isopsoralen and the molecular structures for corresponding products were identified by combined experimental and theoretical studies.展开更多
Multiferroic materials exhibit tremendous potentials in novel magnetoelectric devices such as high-density non-volatile storage.Herein,we report the coexistence of ferroelectricity and ferromagnetism in two-dimensiona...Multiferroic materials exhibit tremendous potentials in novel magnetoelectric devices such as high-density non-volatile storage.Herein,we report the coexistence of ferroelectricity and ferromagnetism in two-dimensional Fedoped In2Se3(Fe0.16In1.84Se3,FIS).The Fe atoms were doped at the In atom sites and the Fe content is^3.22%according to the experiments.Our first-principles calculation based on the density-functional theory predicts a magnetic moment of 5μB per Fe atom when Fe substitutes In sites in In2Se3.The theoretical prediction was further confirmed experimentally by magnetic measurement.The results indicate that pure In2Se3 is diamagnetic,whereas FIS exhibits ferromagnetic behavior with a parallel anisotropy at 2 K and a Curie temperature of^8 K.Furthermore,the sample maintains stable room-temperature ferroelectricity in piezoresponse force microscopy(PFM)measurement after the introduction of Fe atom into the ferroelectric In2Se3 nanoflakes.The findings indicate that the layered Fe0.16In1.84Se3 materials have potential in future nanoelectronic,magnetic,and optoelectronic applications.展开更多
文摘The C--C bond dissociation energy （BDE） is a very important data in research of hydrocarbon cracking reactions, because it reflects the difficulty level of chemical reactions. But it is very difficult to obtain the C--C bond dissociation energy （BDE） by experiments, so using quantum chemistry calculation such as density functional theory （DFT） to study the C--C bond dissociation energy is a very useful means. The impact of acceptor substituents and donor substituents on the C--C bond length distribution was studied.
文摘The pyrolysis of isopsoralen was studied by synchrotron vacuum ultraviolet photoionization mass spectrometry at low pressure. The pyrolysis products were detected at different photon energies, the ratios of products to precursor were measured at various pyrolysis temperatures. The experimental results demonstrate that the main pyrolysis products are primary CO and sequential CO elimination products （C10H602 and C9H60）. The decomposition channels of isopsoralen were also studied by the density functional theory, then rate constants for competing pathways were calculated by the transition state theory. The dominant decom- position channels of isopsoralen and the molecular structures for corresponding products were identified by combined experimental and theoretical studies.
基金financially supported by the National Key Research and Development Program of China (2017YFA0207500)the National Natural Science Foundation of China (61622406, 61571415 and 51502283)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences (XDB30000000)Beijing Academy of Quantum Information Sciences (Y18G04)
文摘Multiferroic materials exhibit tremendous potentials in novel magnetoelectric devices such as high-density non-volatile storage.Herein,we report the coexistence of ferroelectricity and ferromagnetism in two-dimensional Fedoped In2Se3(Fe0.16In1.84Se3,FIS).The Fe atoms were doped at the In atom sites and the Fe content is^3.22%according to the experiments.Our first-principles calculation based on the density-functional theory predicts a magnetic moment of 5μB per Fe atom when Fe substitutes In sites in In2Se3.The theoretical prediction was further confirmed experimentally by magnetic measurement.The results indicate that pure In2Se3 is diamagnetic,whereas FIS exhibits ferromagnetic behavior with a parallel anisotropy at 2 K and a Curie temperature of^8 K.Furthermore,the sample maintains stable room-temperature ferroelectricity in piezoresponse force microscopy(PFM)measurement after the introduction of Fe atom into the ferroelectric In2Se3 nanoflakes.The findings indicate that the layered Fe0.16In1.84Se3 materials have potential in future nanoelectronic,magnetic,and optoelectronic applications.
