CAJ | 학술논문

K（5P）与 H2反应产生KH（Х1Σ＋）的ν″＝0～3振动能级，泛频激发KH至ν″＝17高位振动态。通过测定KH（ν″＝17，3）与CO2碰撞过程中振动能的时间分辨分布（即 Tν的变化过程），研究了高低振动态碰撞传能的不同特点。对于KH（ν″＝17），振动温度 Tν的变化分为三个阶段：第一阶段（0～5μs）Tν迅速下降，能量应主要转移至CO2（0001）振动态或（0000）高位转动态；第二阶段（5～20μs）Tν仅稍有下降，向CO2振动态及高位转动态的能量转移已结束；第三阶段（20μs后） Tν虽然缓慢但明显下降，表明向CO2低转动态及平动能的转移加速。对于KH（ν″＝3），Tν的变化只分为两个阶段：第一阶段（0～10μs）的共振V-R过程迅速降低了振动温度；第二阶段（10～80μs ） Tν有一个缓慢下倾，只能转移到很低的转动态和小的平动能。这些结果表明了振动激发态分子与基态分子碰撞中仅用单一速率系数不能正确揭示复杂平衡过程的本质，不同的阶段应该用不同的速率系数来描述。利用瞬时吸收技术得到CO2（0000）和（0001）的原生态转动布居分布，通过速率方程分析，得到平衡过程中不同阶段的速率系数。
K（5P）여 H2반응산생KH（Х1Σ＋）적ν″＝0～3진동능급，범빈격발KH지ν″＝17고위진동태。통과측정KH（ν″＝17，3）여CO2팽당과정중진동능적시간분변분포（즉 Tν적변화과정），연구료고저진동태팽당전능적불동특점。대우KH（ν″＝17），진동온도 Tν적변화분위삼개계단：제일계단（0～5μs）Tν신속하강，능량응주요전이지CO2（0001）진동태혹（0000）고위전동태；제이계단（5～20μs）Tν부초유하강，향CO2진동태급고위전동태적능량전이이결속；제삼계단（20μs후） Tν수연완만단명현하강，표명향CO2저전동태급평동능적전이가속。대우KH（ν″＝3），Tν적변화지분위량개계단：제일계단（0～10μs）적공진V-R과정신속강저료진동온도；제이계단（10～80μs ） Tν유일개완만하경，지능전이도흔저적전동태화소적평동능。저사결과표명료진동격발태분자여기태분자팽당중부용단일속솔계수불능정학게시복잡평형과정적본질，불동적계단응해용불동적속솔계수래묘술。이용순시흡수기술득도CO2（0000）화（0001）적원생태전동포거분포，통과속솔방정분석，득도평형과정중불동계단적속솔계수。
ThevibrationallevelsofKH(Х1Σ+ ν″=0~3)weregeneratedinthereactionofK(5P)withH2 .Thevibrationallyex-cited KH(ν″=17) was populated by an overtone pump-probe configuration .Different characteristics of collisional energy transfer in highly and lowly excited vibrational levels of KH and CO2 were investigated through measuring the time-resolved distribution of vibrational energy in KH(ν″=17 ,3)+CO2 collisions .For KH(ν″=17) ,there existed three principal regions of vibration tem-perature (Tν) in this equilibration process .The initial phase consists of very rapid fall in Tνwithin ~5 μs ,and the vibrational energy of KH(ν″=17) is mainly transferred to the vibrational levels of CO2 (0001) or high rotational levels of CO2 (0000) .The second phase (5~20 μs) has a slight decline in Tν,and the process of energy transfer to vibrational levels or high rotational lev-els of CO2 has already finished .The vibration temperature of the third phase has a slightly more rapid decline compared with the last phase .This phase shows that the process of transfer to lowly rotational levels and translation energy of CO 2 is accelerated . The equilibration of vibrationally excited KH (ν″=3) in CO2 was also investigated .There are similarities to the behavior of KH (ν″=17) in CO2 plot ,but also are significant differences .Once the initial resonant V-R exchange has equalized vibrational tem-peratures ,there is a very slow linear decline in Tνwith equilibrium attained within ~80 μs .This same point is reached within 15μs for KH (ν″=17) .The data demonstrate that single rate coefficient measurements are unlikely to capture the complex nature of processes that generally are multistaged with different relaxation rates characterizing each different stage .Examination of the quantum state distributions reveals that these distinct stages reflect the dominance of specific energy transfer mechanisms ,some of which are inherently fast and others are much slower .The energy gain into CO2 resulting from collisions with excited KH was probed using transient absorption techniques .Distributions of nascent CO2 rotational populations in both ground (0000) state and the vibrationally excited (0001) state were determined .A kinetic model was developed to describe rate coefficients for ap-pearance of CO2 states resulting from collisions with excited KH .These experiments show that collisions resulting in CO2 (0000) are accompanied by substantial excitation in rotation while the vibrationally excited CO 2 (0001) state has rotational energy distri-butions near the initial distributions .