三维含时量子散射研究H+ClH体系

用三维含时量子散射理论模拟了H+GlH体系在BW2,mBW2,G3势能面上的动力学行为.其计算结果表明,振动量子态对反应几率影响很大;势能面的地形对转动量子态如何影响反应几率起重要作用;反应几率表现出"黄金规则".此外,BW2,mBW2势能面上的反应几率几乎相同,而G3势能面上的反应几率较前者低,大概由于G3的势垒高的缘故.     

Application of symplectic algorithms to QCT calculation:H+H_2 system

The basic theory of symplectic algorithm was introduced. A comparison between Runge-Kutta method and symplectic integration method was preformed in the simulation of the long time behavior of H + H2 system on BKMP potential energy surface. Our results reveal a dis-sipative behavior in the integral of ordinary differential equation by the fourth order Runge-Kutta method, which causes incorrect simulation results in QCT calculations. However, when the symplectic integration method is applied, the dissipative behavior is not found in the same system. When the initial state is the same, the energy deviation of fourth order symplectic integral method is almost one percent of that of fourth order Runge-Kutta method in a 60000-step simulation, and that of sixth order symplectic integral method is much less. These results show that the symplectic integral methods are always the better choice in the integral calculation of the long time behavior in maintaining energy conservation.     

H+H2体系的态(R)-态(TS)-态(P)理论研究

H+H₂体系的辛准经典轨迹(SQCT)计算表明: 碰撞轨迹分为A, B两种类型, A型是经过过渡态鞍点的, B型是不经过过渡态鞍点的. A型轨迹不全发生反应, B型轨迹却也可发生反应. A, B两种类型轨迹的配分及其反应性, 与反应物初始态(R)有关. 这种轨迹类型A, B影响着产物态(P)(即振转态)分布及其角度分布. 初步建立了化学反应态(R)-态(TS)-态(P)理论研究的雏形, 深化了对Eyring过渡态理论的理解.     

共线量子散射方法研究D+CID体系

用共线量子散射方法计算D+CID体系的反应几率和传能几率。发现存在很强的振荡现象。体系的碰撞中间态的寿命的计算结果为fs-ps数量级。当某一反应通道打开时,在能量阈值附近通常都伴随着一些长寿命的碰撞中间态。这一点该体系中表现很比较明显。     

微波等离子体下甲烷偶联制乙炔的研究

通过优化设计矩形波导谐振腔微波化学反应器,可以大幅提高微波等离子体下甲烷转化率（最高为93．7％）、C2烃收率（最高为91．0％）和乙炔收率（最高为88．6％）．且优化后,在实验的压强范围内,甲烷转化率和C2烃收率较为稳定,C2烃主要是乙炔,其选择性都在90％以上．生成乙炔的能量产率和时空产率也都比较高．利用发射光谱法对微波等离子体下甲烷偶联制乙炔的反应进行了诊断研究,在300nm～750nm波长范围内激发态物种有：CH,C2,H2,Hα-根据反应产物和激发态物种从化学反应热力学和动力学上对反应机理进行了初步探索．     

辛算法在准经典轨迹计算中的应用: H+H2体系

采用辛算法模拟了H + H₂在BKMP势能面上的长时间动力学行为, 并和Runge-Kutta方法计算的结果进行了比较.结果表明,采用Runge-Kutta方法模拟长时动力学行为时体系中出现动力学耗散行为,导致无法真实的模拟体系的物理实际;而采用辛算法模拟精确度更高,四阶辛算法误差只有Runge-Kutta法的约百分之一,六阶辛算法的误差则更小,体系中也未见动力学耗散行为.这些结果说明,在进行长时动力学行为模拟的时候,在保持体系能量守恒性上,辛算法应当是一种更好的积分方法.     

三维含时量子散射研究H + CIH体系

用三维含时量子散射理论模拟了H+CIH体系在BW2,mBW2,G3势能面上的动力学行为,其计算结果表明,振动量子态对反应几率影响很大;势能面的地形对转动量子态如何影响反应几率起重要作用;反应几率表现出“黄金规则”,此外,BW2,mBW2势能面上的反应几率几乎相同,而G3势能面上的反应几率较前者低,大概由于G3的势垒高的缘故。     

A Novel Algorithm for the Sound Field of Elliptically Shaped Transducers

An alternative extension to the Gaussian-beam expansion technique is presented for efficient computation of the Fresnel field integral for elliptically symmetric sources. With a known result that the circ function is approximately decomposed into a sum of Gaussian functions, the cosine function is similarly expanded by the Bessel-Fourier transform. Two expansions are together inserted into this integral, it is then expressible in terms of the simple algebraic functions. The numerical examples for the elliptical and uniform piston transducers are presented, in good agreement with the results given by other methods. The approach is applicable to treat the field radiation problem for a large and important group of piston sources in acoustics.     

State(R)-state(TS)-state(P) theoretical study of H+H_2 system

The calculation of H + H2 system by symplectic quasiclassical trajectory (SQCT) shows that there are two types of collision trajectories A and B, i.e., type A trajectory passes the saddle point of transition state (TS), whereas type B trajectory does not pass the saddle point of transition state. Not all the reactants of type A trajectory are reactive, while not all of type B trajectory are nonreactive. The partition and reactivity of these two types of trajectories are affected by reactant state(R), furthermore, the types of trajectories affect the state and angle distributions of products. Not only the rudiment framework for theoretical study on state(R)-state(TS)-state(P) is established, but also the further understanding of transition state theory (TST) of Eyring is investigated in this paper.     

辛准经典轨迹法研究Cl+H2反应

用辛准经典轨迹法模拟了Cl+H2反应在mBW2势能面上的动力学行为。研究了各种初始条件下的反应碰撞截面,产物的能量分配,角度分布和态分布。另外,我们还比较了反应物的三种能量形式(平动能,转动能和振动能)对反庆的有效性。