摘要:

AbstractData from several smog chamber reaction vessels have been analyzed in an attempt to elucidate the chemical species which are responsible for chamber specific background phenomena, and the nature of the processes which determine the heterogeneous interactions of those species. There is good evidence for the emission of a compound which yields both NOx, and free radicals (probably HONO) and emissions of reactive organics (e.g. HCHO) may also be deduced. Total integrated chamber emission of these compounds may be as high as 20 to 60 ppb during a typical smog chamber experiment. In addition to the direct emission of these contaminants, the surface reaction of NO2 and H2O to HONO is examined. In some cases this reaction may have as great an effect on a smog chamber experiment as the emission of trace contaminants. Overall chamber perturbations to gas phase chemistry have been estimated for several experiments and were found to be less than 20 percent in the majority of cases, although higher perturbations were found in experiments involving compounds of low reactivity such as butane.

ISSN:0538-8066    

DOI:10.1002/kin.550220602

出版商:John Wiley&Sons, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe reaction mechanisms for oxidation of CH3CCl2and CCl3CH2radicals, formed in the atmospheric degradation of CH3CCl3have been elucidated. The primary oxidation products from these radicals are CH3CClO and CCl3CHO, respectively. Absolute rate constants for the reaction of hydroxyl radicals with CH3CCl3have been measured in 1 atm of Argon at 359, 376, and 402 K using pulse radiolysis combined with UV kinetic spectroscopy giving

ISSN:0538-8066    

DOI:10.1002/kin.550220603

出版商:John Wiley&Sons, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe gas‐phase reaction of methacrolein with the OH radical, in the presence of NOx, was investigated at 298 ± 2 K and atmospheric pressure of air. Hydroxyacetone, methylglyoxal, a peroxyacyl nitrate identified as CH2 C(CH3)C(O)OONO2(peroxymethacryloyl nitrate), formaldehyde, CO, and CO2were observed to be the major products. The product yield data for these compounds show that OH radical addition to the>C  C

ISSN:0538-8066    

DOI:10.1002/kin.550220604

出版商:John Wiley&Sons, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractRate constants for the reactions of OH radicals and Cl atoms with diethyl sulfide (DES), di‐n‐propyl sulfide (DPS), and di‐n‐butyl sulfide (DBS) have been determined at 295 ± 3 K and a total pressure of 1 atm. Hydroxyl radical rate data was obtained using the absolute technique of pulse radiolysis combined with kinetic spectroscopy. The chlorine atom rate constants were measured using a conventional photolytic relative rate method. The rate constant for the reaction of Cl atoms with dimethyl sulfide (DMS) was also determined. The following rate constants were obtained:\documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{l} k({\rm OH + DES) = (}11.6 \pm 2) \times 10^{ - 12} {\rm cm}^{\rm 3} {\rm molecule}^{{\rm - 1}} {\rm s}^{{\rm - 1}} \\ k({\rm OH + DPS) = (}21.5 \pm 3) \times 10^{ - 12} {\rm cm}^{\rm 3} {\rm molecule}^{{\rm - 1}} {\rm s}^{{\rm - 1}} \\ k({\rm OH + DBS) = (}37.4 \pm 5) \times 10^{ - 12} {\rm cm}^{\rm 3} {\rm molecule}^{{\rm - 1}} {\rm s}^{{\rm - 1}} \\ k({\rm Cl + DMS) = (}32.2 \pm 3) \times 10^{ - 11} {\rm cm}^{\rm 3} {\rm molecule}^{{\rm - 1}} {\rm s}^{{\rm - 1}} \\ k({\rm Cl + DES) = (}44.1 \pm 4) \times 10^{ - 11} {\rm cm}^{\rm 3} {\rm molecule}^{{\rm - 1}} {\rm s}^{{\rm - 1}} \\ k({\rm Cl + DPS) = (}51.8 \pm 4) \times 10^{ - 11} {\rm cm}^{\rm 3} {\rm molecule}^{{\rm - 1}} {\rm s}^{{\rm - 1}} \\ k({\rm Cl + DBS) = (}64.6 \pm 2) \times 10^{ - 11} {\rm cm}^{\rm 3} {\rm molecule}^{{\rm - 1}} {\rm s}^{{\rm - 1}} \\ \end{array} $$\end{

ISSN:0538-8066    

DOI:10.1002/kin.550220605

出版商:John Wiley&Sons, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe decomposition kinetics of disilane with added butadiene, trisilane both neat and with added butadiene, trimethylsilane or H2, and normal and iso‐tetrasilane both neat and in the presence of added butadiene are reported. Arrhenius parameters of the primary dissociation reactions are determined: A‐factors suggest that polysilane decompositions (1) have similar intrinsic activation entropies (ΔS‡ ≈︁ 6.2 ± 5 e.u.) and (2) have activation energies which increase with increasing reaction endothermicities. Relative trapping efficiencies of SiH4, Si2H6, Si3H8, C4H6, Me3SiH, and H2toward SiH2and SiH3SiH are also determined. Other results include the heat of formation of silylsilylene, ΔH ∘f(SiH3SiH) = 75.3 Kcal/mol, and the activation energy for 1,1‐H2elimination from disilane (E

ISSN:0538-8066    

DOI:10.1002/kin.550220606

出版商:John Wiley&Sons, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe reaction rates of SO3with CH3OH in He were measured at total pressures of 0.7–1.6 torr in flow tubes. The concentration of SO3was monitored by the SO2* fluorescence from excitation of SO3at 147 nm. The reaction rate constant of SO3+ CH3OH in the gas phase is determined to be (1.17 ± 0.16) × 10−13cm3molec−1s−1at room te

ISSN:0538-8066    

DOI:10.1002/kin.550220607

出版商:John Wiley&Sons, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractEthylene oxidation and pyrolysis was modeled using a comprehensive kinetic reaction mechanism. This mechanism is an updated version of one developed earlier. It includes the most recent findings concerning the kinetics of the reactions involved in the oxidation of ethylene. The proposed mechanism was tested against ethylene oxidation experimental data (molecular species concentration profiles) obtained in jet stirred reactors (1–10 atm, 880–1253 K), ignition delay times measured in shock tubes (0.2–12 atm, 1058–2200 K) and ethylene pyrolysis data in shock tube (2–6 atm, 1700–2200 K). The general prediction of concentration profiles of minor species formed during ethylene oxidation is improved in the present model by using more accurate kinetic data for several reactions (principally: HO2+ HO2→ H2O2+ O2, C2H4+ OH → C2H3+ H2O, C2H2+ OH → Product

ISSN:0538-8066    

DOI:10.1002/kin.550220608

出版商:John Wiley&Sons, Inc.    

年代:1990

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550220601

出版商:John Wiley&Sons, Inc.    

年代:1990

数据来源: WILEY