Browsing by Author "WANG, NS"

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KINETICS OF THE REACTION OF HSO WITH O3 AT TEMPERATURES 273-423 K
(1994-01-01)
LEE, YY
;
LEE, YP
;
WANG, NS
;
應用化學系
;
Department of Applied Chemistry
The rate coefficient of the reaction of HSO with O3 at five temperatures in the range 273-423 K was determined by means of the discharge-flow/laser-induced-fluorescence technique. The laser-induced fluorescence of HSO was detected by the gated photon-counting technique; a detection limit approximately 4 X 10(9) molecules cm -3 was achieved. The reaction was carried out under pseudo-first-order conditions with [03] much greater than [HSO]; the rate coefficient was determined to be k = (4.7 +/- 1.0) X 10(-14) CM3 Molecule-1 s-1 at 298 K, approximately 30% greater than, but within experimental uncertainty of the only previous measurement by Wang and Howard by means of the discharge-flow/laser-magnetic-resonance technique. The temperature dependence of the rate coefficient is expressed in the Arrhenius form, k(T) = (2.1 +/- 0.7) X 10(-12) exp[- (1120 +/- 320)/T] cm3 molecule-1 s-1.
KINETICS OF THE REACTIONS OF NCO WITH NO AND NO2
(1995-11-01)
JUANG, DY
;
LEE, JS
;
WANG, NS
;
應用化學系
;
Department of Applied Chemistry
The rate coefficients of the reactions of NCO radicals with NO and NO2: (1) NCO + NO --> products (293-836 K) and : (2) NCO + NO2 --> products (294-774 K) were measured by means of laser photolysis and-laser induced fluorescence technique in the indicated temperature ranges. NCO radicals were produced from the reaction of CN, from photodissociation of ICN or BrCN, with O-2. The concentration of NCO was monitored with a dye laser set at 414.95 nm. We determined k(1) = 1.73 x 10(-5) T--2.01 exp(-470/T) cm(3) molecule(-1) s(-1) that agrees with published results at room temperature and confirms the temperature dependence of an early report. A non-Arrhenius negative temperature dependence of k(2) was observed in-this work that agrees satisfactorily with results for a shock tube(18) near 1250 K. We obtained k(2) = 6.4 x 10(-10) T--0.646 exp(164/T) cm(3) molecule(-1) s(-1) for 1250 K greater than or equal to T greater than or equal to 294 K by combining data of these two measurements. Our result at 294 K and the temperature dependence disagree with results of two previous investigations. (C) 1995 John Wiley & Sons, Inc.
RATE COEFFICIENTS OF THE REACTIONS OF CN AND NCO WITH O2 AND NO2 AT 296-K
(1993-08-01)
YOU, YY
;
WANG, NS
;
交大名義發表
;
應用化學系
;
National Chiao Tung University
The rate coefficients of the reactions of CN and NCO radicals with O2 and NO2 at 296 K: (1) CN + O2 --> products; (2) CN + NO2 --> products; (3) NCO + O2 --> products and (4) NCO + NO2 --> products have been measured with the laser photolysis-laser induced fluorescence technique. We obtained k1 = (2.1 +/- 0.3) x 10(-11) and k2 = (7.2 +/- 1.0) x 10(-11) cm3 molecule-1 s-1 which agree well with published results. As no reaction was observed between NCO and O2 at 297 K, an upper limit of k3 < 4 x 10(-17) cm3 molecule-1 s-1 was estimated. The reaction of NCO with NO2 has not been investigated previously. We measured k4 = (2.2 +/- 0.3) x 10(-11) cm3 molecule-1 s-1 at 296 K.
RATES OF THE REACTIONS CN+H2CO AND NCO+H2CO IN THE TEMPERATURE-RANGE 294-769 K
(1995-11-15)
CHANG, YW
;
WANG, NS
;
應用化學系
;
Department of Applied Chemistry
The rate coefficients of the reactions: (1) CN + H2CO --> products, and (2) NCO + H2CO --> products in the temperature range 294-769 K have been determined by means of the laser photolysis-laser induced fluorescence technique. Our measurements show that reaction (1) is rapid: k(1)(294 K) = (1.64 +/- 0.25) x 10(-11) cm(3) molecule(-1) s(-1); the Arrhenius relation was determined as k(1) = (6.7 +/- 1.0) x 10(-11) exp[(-412 +/- 20)/T] cm(3) molecule(-1) s(-1). Reaction (2) is approximately a tenth as rapid as reaction (1) and the temperature dependence of k, does not conform to the Arrhenius form: k(2) = 4.62 x 10(-17)T(1.71) exp(198/T) cm(3) molecule(-1) s(-1). Our values are in reasonable agreement with the only reported measurement of k(1); the rate coefficients for reaction (2) have not been previously reported.