Hua Da-Yin, Ma Yu-Qiang
National Laboratory of Solid State Microstructures, Nanjing University, China.
Phys Rev E Stat Nonlin Soft Matter Phys. 2002 Sep;66(3 Pt 2A):036101. doi: 10.1103/PhysRevE.66.036101. Epub 2002 Sep 4.
We study a monomer-dimer reaction model in two dimensions in which the adsorption process of a dimer on the surface sites is separated into two steps (i.e., B2+-->B2 , and B2 * +-->2B, where * is an empty site), as first introduced by Evans and co-workers. It is clear that the dissociation of a dimer is dependent on the complicated configuration of the adsorbate. We show that the continuous transition from the reactive state to the O-passivated state and the discontinuous transition to the CO-passivated state both shift toward higher values of the fraction p of the monomer in gas phase but the reaction window decreases compared to the Ziff-Gulari-Barshad model. For the model studied here, the critical exponents of the continuous phase transition still exhibit a directed percolation character as expected.
我们研究了二维的单体 - 二聚体反应模型，其中二聚体在表面位点的吸附过程被分为两个步骤（即，B2 + * --> B2 *，以及B2 * + * --> 2B *，其中 * 表示空位点），这是由埃文斯及其同事首次提出的。很明显，二聚体的解离取决于吸附质的复杂构型。我们表明，从反应态到O钝化态的连续转变以及到CO钝化态的不连续转变都向气相中单体分数p的更高值移动，但与齐夫 - 古拉瑞 - 巴沙德模型相比，反应窗口减小。对于此处研究的模型，连续相变的临界指数仍如预期的那样表现出定向渗流特征。
