The rate constants for the C1 atom reaction with three branched ketones have been measured at 298 ± 2 K and 760 Torr using the relative rate method in the absence of NO. The rate constants values obtained （in un...The rate constants for the C1 atom reaction with three branched ketones have been measured at 298 ± 2 K and 760 Torr using the relative rate method in the absence of NO. The rate constants values obtained （in units of 10^-10 cm^3/（molecule.sec）） are： k（2-methyl-3-pentanone） = 1.07 ± 0.26, k（3-methyl-2-pentanone） =1.21 ± 0.26, and k（4-methyl-2-pentanone） = 1.35 ± 0.27. Combining the chemical kinetic data obtained by this study with those reported for other ketones, a revised Structure Activity Relationship （SAR） parameter and R group reactivity （kR of R（O）R＇ and CHx （x = 1, 2, 3） group reactivity （kCHx） toward C1 atoms were proposed. In addition, the products from the three reactions in the presence of NO were also identified and quantified by using PTR-ToF-MS and GC-FID, and the yields of the identified products are： acetone （39% ± 8%） ＋ ethanal （78% ± 12%）, 2-butanone （22% ± 2%） ＋ ethanal （75% ± 10%） ＋ propanal （14% ± 1%） and acetone （26% ± 3%） ＋ 2-methylpmpanal （24% ± 2%）, for C1 atoms reaction with 2-methyl-3-pentanone, 3-methyl-2-pentanone and 4-methyl-2-pentanone, respectively. Based on the obtained results, the reaction mechanisms of C1 atoms with these three ketones are proposed.展开更多
The reaction of Cl atoms with two C5aldehydes(3-methyl-2-butenal and 3-methylbutanal)were investigated by proton-transfer-reaction mass spectrum(PTR-MS)using smog chamber at 298±1 K and 760 Torr.A relative rate m...The reaction of Cl atoms with two C5aldehydes(3-methyl-2-butenal and 3-methylbutanal)were investigated by proton-transfer-reaction mass spectrum(PTR-MS)using smog chamber at 298±1 K and 760 Torr.A relative rate method was used to determine the rate constants of the title reactions with m-xylene and trans-2-butene as reference compounds:(3.04±0.18)×10^(-10)and(2.07±0.14)×10^(-10)cm^(3)/(molecule·sec)for 3-methyl-2-butenal and 3-methylbutanal,respectively.Additionally,the gas-phase products were also identified by PTR-MS,and the possible reaction mechanisms were proposed basing on the identified products.The detected gas-phase products are similar for two C5aldehydes reactions,mainly including small molecules of aldehydes,ketones and chlorinated aldehyde compounds.The atmospheric lifetimes(τ)calculated for 3-methyl-2-butenal(τ=7.0 hr,marine boundary layer(MBL))and 3-methylbutanal(τ=10.3 hr,MBL)according to the obtained rate constants.The results indicate that Cl atoms at MBL are competitive with OH radicals for the degradation contribution of C5aldehyde compounds.展开更多
The growth of {100}-oriented CVD diamond film under two modifications ofJ-B-H model at low substrate temperatures was simulated by using a revised KMC method at atomicscale. The results were compared both in Cl-contai...The growth of {100}-oriented CVD diamond film under two modifications ofJ-B-H model at low substrate temperatures was simulated by using a revised KMC method at atomicscale. The results were compared both in Cl-containing systems and in C-H system as follows: (1)Substrate temperature can produce an important effect both on film deposition rate and on surfaceroughness; (2) Aomic Cl takes an active role for the growth of diamond film at low temperatures; (3){100}-oriented diamond film cannot deposit under single carbon insertion mechanism, which disagreeswith the predictions before; (4) The explanation of the exact role of atomic Cl is not provided inthe simulation results.展开更多
The gas phase thermodynamic properties of 135 polychlorinated xanthones(PCXTs)are calculated using a combination of quantum mechanical computations performed with the Gaussian 03 program at the B3LYP/6-311G**level.It ...The gas phase thermodynamic properties of 135 polychlorinated xanthones(PCXTs)are calculated using a combination of quantum mechanical computations performed with the Gaussian 03 program at the B3LYP/6-311G**level.It is found that the chlorine substitution pattern strongly influences the thermodynamic properties of the compounds.The thermodynamic properties of congeners with the same number of chlorines also depend on the chlorine substitution pattern,especially for ortho-substituted congeners.PCXT congeners with one phenyl ring fully chlorinated are found to be the least stable among the analogues.The effect of the chlorine substitution pattern is quantitatively studied by considering the number and position of Cl atom substitution(NPCS).The results show that the NPCS model may be used to predict the thermodynamic properties for all 135 PCXT congeners. In addition,the values of molar heat capacities at constant pressure(cp,m)from 200 to 1000 K for PCXT congeners are calculated,and the temperature dependence relation of this parameter is obtained using the least-squares method.展开更多
The growth of (100} oriented CVD (Chemical Vapor Deposition) diamond film under Joe-Badgwell-Hauge (J-B-H) model is simulated at atomic scale by using revised KMC (Kinetic Monte Carlo) method. The results show that: (...The growth of (100} oriented CVD (Chemical Vapor Deposition) diamond film under Joe-Badgwell-Hauge (J-B-H) model is simulated at atomic scale by using revised KMC (Kinetic Monte Carlo) method. The results show that: (1) under Joe's model, the growth mechanism from single carbon species is suitable for the growth of (100) oriented CVD diamond film in low temperature; (2) the deposition rate and surface roughness (Rq) under Joe's model are influenced intensively by temperature (Ta) and not evident bymass fraction W of atom chlorine; (3)the surface roughness increases with the deposition rate, i.e. the film quality becomes worse with elevated temperature, in agreement with Grujicic's prediction; (4) the simulation results cannot make sure the role of single carbon insertion.展开更多
基金supported by Labex Voltaire (ANR-10-LABX-100-01), ARD PIVOTS program (supported by the Centre-Val de Loire regional council)the European Union's Horizon 2020 Research and Innovation Programme through the EUROCHAMP2020 Infrastructure Activity under grant agreement No. 730997+1 种基金the China Scholarship Council for the financial supportsupported by the Natural Science Foundation of China (No. 41305124)
文摘The rate constants for the C1 atom reaction with three branched ketones have been measured at 298 ± 2 K and 760 Torr using the relative rate method in the absence of NO. The rate constants values obtained （in units of 10^-10 cm^3/（molecule.sec）） are： k（2-methyl-3-pentanone） = 1.07 ± 0.26, k（3-methyl-2-pentanone） =1.21 ± 0.26, and k（4-methyl-2-pentanone） = 1.35 ± 0.27. Combining the chemical kinetic data obtained by this study with those reported for other ketones, a revised Structure Activity Relationship （SAR） parameter and R group reactivity （kR of R（O）R＇ and CHx （x = 1, 2, 3） group reactivity （kCHx） toward C1 atoms were proposed. In addition, the products from the three reactions in the presence of NO were also identified and quantified by using PTR-ToF-MS and GC-FID, and the yields of the identified products are： acetone （39% ± 8%） ＋ ethanal （78% ± 12%）, 2-butanone （22% ± 2%） ＋ ethanal （75% ± 10%） ＋ propanal （14% ± 1%） and acetone （26% ± 3%） ＋ 2-methylpmpanal （24% ± 2%）, for C1 atoms reaction with 2-methyl-3-pentanone, 3-methyl-2-pentanone and 4-methyl-2-pentanone, respectively. Based on the obtained results, the reaction mechanisms of C1 atoms with these three ketones are proposed.
基金supported by the National Natural Science Foundation of China(No.91744204)Natural Science Foundation of Hebei Province(No.B2019205113)+3 种基金the Education Department Foundation of Hebei Province(No.QN2020190)the China Postdoctoral Science Foundation(No.2020M670684)the Postdoctoral Foundation of Hebei Province(No.B2020003017)the Science Foundation of Hebei Normal University(No.L2020B12)。
文摘The reaction of Cl atoms with two C5aldehydes(3-methyl-2-butenal and 3-methylbutanal)were investigated by proton-transfer-reaction mass spectrum(PTR-MS)using smog chamber at 298±1 K and 760 Torr.A relative rate method was used to determine the rate constants of the title reactions with m-xylene and trans-2-butene as reference compounds:(3.04±0.18)×10^(-10)and(2.07±0.14)×10^(-10)cm^(3)/(molecule·sec)for 3-methyl-2-butenal and 3-methylbutanal,respectively.Additionally,the gas-phase products were also identified by PTR-MS,and the possible reaction mechanisms were proposed basing on the identified products.The detected gas-phase products are similar for two C5aldehydes reactions,mainly including small molecules of aldehydes,ketones and chlorinated aldehyde compounds.The atmospheric lifetimes(τ)calculated for 3-methyl-2-butenal(τ=7.0 hr,marine boundary layer(MBL))and 3-methylbutanal(τ=10.3 hr,MBL)according to the obtained rate constants.The results indicate that Cl atoms at MBL are competitive with OH radicals for the degradation contribution of C5aldehyde compounds.
基金This project was supported by National Natural Science Foundation of China (No.59872003).]
文摘The growth of {100}-oriented CVD diamond film under two modifications ofJ-B-H model at low substrate temperatures was simulated by using a revised KMC method at atomicscale. The results were compared both in Cl-containing systems and in C-H system as follows: (1)Substrate temperature can produce an important effect both on film deposition rate and on surfaceroughness; (2) Aomic Cl takes an active role for the growth of diamond film at low temperatures; (3){100}-oriented diamond film cannot deposit under single carbon insertion mechanism, which disagreeswith the predictions before; (4) The explanation of the exact role of atomic Cl is not provided inthe simulation results.
基金Supported by the National Natural Science Foundation of China （20977046, 20737001）.
文摘The gas phase thermodynamic properties of 135 polychlorinated xanthones(PCXTs)are calculated using a combination of quantum mechanical computations performed with the Gaussian 03 program at the B3LYP/6-311G**level.It is found that the chlorine substitution pattern strongly influences the thermodynamic properties of the compounds.The thermodynamic properties of congeners with the same number of chlorines also depend on the chlorine substitution pattern,especially for ortho-substituted congeners.PCXT congeners with one phenyl ring fully chlorinated are found to be the least stable among the analogues.The effect of the chlorine substitution pattern is quantitatively studied by considering the number and position of Cl atom substitution(NPCS).The results show that the NPCS model may be used to predict the thermodynamic properties for all 135 PCXT congeners. In addition,the values of molar heat capacities at constant pressure(cp,m)from 200 to 1000 K for PCXT congeners are calculated,and the temperature dependence relation of this parameter is obtained using the least-squares method.
基金Supported by the Science Foundation of Henan Province(2008A150005)Science Foundation of Henan University (2009YBZR013,SBGJ090507)Doctor Foundation of Henan University
基金[This work was financially supported by National Natural Science Founds of China (No. 59872003).]
文摘The growth of (100} oriented CVD (Chemical Vapor Deposition) diamond film under Joe-Badgwell-Hauge (J-B-H) model is simulated at atomic scale by using revised KMC (Kinetic Monte Carlo) method. The results show that: (1) under Joe's model, the growth mechanism from single carbon species is suitable for the growth of (100) oriented CVD diamond film in low temperature; (2) the deposition rate and surface roughness (Rq) under Joe's model are influenced intensively by temperature (Ta) and not evident bymass fraction W of atom chlorine; (3)the surface roughness increases with the deposition rate, i.e. the film quality becomes worse with elevated temperature, in agreement with Grujicic's prediction; (4) the simulation results cannot make sure the role of single carbon insertion.
