1,1,2,2,3,3,4-Heptafluorocyclopentane(F7A)has considerable potential to be a new halon replacement due to its environmental friendliness and low-toxicity.However,the reaction processes of F7A with hydroxyl and hydroge...1,1,2,2,3,3,4-Heptafluorocyclopentane(F7A)has considerable potential to be a new halon replacement due to its environmental friendliness and low-toxicity.However,the reaction processes of F7A with hydroxyl and hydrogen free radicals,which are of great importance for investigating its fire suppression mechanisms,are still unclear.In this paper,ab inito and density functional theory are used to deduce the possible reaction pathways for the reactions of F7A with hydroxyl and hydrogen free radicals at the CCSD/cc-pVDZ//B3LYP/6-311++G(d,p)level of theory.Two distinct reaction pathways including ten elementary reaction channels for F7A with hydroxyl free radical,and five distinct reaction pathways including twenty elementary reaction channels for F7A with hydrogen free radical are investigated.The geometries,vibrational frequencies and reaction energy barriers are also determined.Based on the calculated results,the possible reaction mechanisms are proposed and discussed.The most feasible reaction channel for F7A with hydroxyl free radical is that leads to CH(OH)CH_(2)(CF_(2))_(3)+•F,and the most feasible reaction channel for F7A with hydrogen free radical is that leads to(CF_(2))_(3)CH_(2)CH•+HF.The study is helpful to further study its fire suppression mechanisms and promote it to be a new generation of halon replacement.展开更多
An important tool for the construction of periodic wavelet frame with the help of extension principles was presented in the Fourier domain by Zhang and Saito [Appl. Comput. Harmon. Anal., 2008, 125： 68-186]. We exten...An important tool for the construction of periodic wavelet frame with the help of extension principles was presented in the Fourier domain by Zhang and Saito [Appl. Comput. Harmon. Anal., 2008, 125： 68-186]. We extend their results to the dilation matrix cases in two aspects. We first show that the periodization of any wavelet frame constructed by the unitary extension principle formulated by Ron and Shen is still a periodic wavelet frame under weaker conditions than that given by Zhang and Saito, and then prove that the periodization of those generated by the mixed extension principle is also a periodic wavelet frame if the scaling functions have compact supports.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant no.51176078).
文摘1,1,2,2,3,3,4-Heptafluorocyclopentane(F7A)has considerable potential to be a new halon replacement due to its environmental friendliness and low-toxicity.However,the reaction processes of F7A with hydroxyl and hydrogen free radicals,which are of great importance for investigating its fire suppression mechanisms,are still unclear.In this paper,ab inito and density functional theory are used to deduce the possible reaction pathways for the reactions of F7A with hydroxyl and hydrogen free radicals at the CCSD/cc-pVDZ//B3LYP/6-311++G(d,p)level of theory.Two distinct reaction pathways including ten elementary reaction channels for F7A with hydroxyl free radical,and five distinct reaction pathways including twenty elementary reaction channels for F7A with hydrogen free radical are investigated.The geometries,vibrational frequencies and reaction energy barriers are also determined.Based on the calculated results,the possible reaction mechanisms are proposed and discussed.The most feasible reaction channel for F7A with hydroxyl free radical is that leads to CH(OH)CH_(2)(CF_(2))_(3)+•F,and the most feasible reaction channel for F7A with hydrogen free radical is that leads to(CF_(2))_(3)CH_(2)CH•+HF.The study is helpful to further study its fire suppression mechanisms and promote it to be a new generation of halon replacement.
基金Acknowledgements The authors express their gratitude to the anonymous referees for their kind suggestions and useful comments on the original manuscript, which resulted in this final version. This work was supported by the National Natural Science Foundation of China （No. 61071189）, the Natural Science Foundation for the Education Department of Henan Province of China （No. 13A110072）, and the Natural Science Foundation of Henan University （No. 2011YBZR001）.
文摘An important tool for the construction of periodic wavelet frame with the help of extension principles was presented in the Fourier domain by Zhang and Saito [Appl. Comput. Harmon. Anal., 2008, 125： 68-186]. We extend their results to the dilation matrix cases in two aspects. We first show that the periodization of any wavelet frame constructed by the unitary extension principle formulated by Ron and Shen is still a periodic wavelet frame under weaker conditions than that given by Zhang and Saito, and then prove that the periodization of those generated by the mixed extension principle is also a periodic wavelet frame if the scaling functions have compact supports.
