dimer-dimer模型在不均匀催化表面上的动力学相变

研究了具有中间产物的dimer-dimer(DD)模型的非平衡相变行为.分别讨论了只有一种反应物脱附时在无惰性点(inert-site)表面上的动力学相变行为,在有惰性点的表面上无反应物脱附的相变行为,以及二者综合考虑时催化表面的动力学相变行为.通过这些讨论得出:脱附使得更多的格点变空,有利于反应的进一步进行;脱附率越大,上述现象越明显,反应窗口也就越宽;而晶格表面的缺陷点的存在,阻碍了反应粒子的吸附,不利于反应的进行,具体表现就是使反应窗口变窄,最终生成物浓度变小.这种惰性格点所占比例越大,上述现象越突出,直至浓度达到一定值时,非惰性格点难以形成大的渗流集团,不再出现反应窗口.

DYNAMICS OF PHASE TRANSITION OF DIMER-DIMER MODEL ON THE NONHOMOGENEOUS CATALYTIC SURFACE

Non equalibrium phase transition of DD model with middle product is investigated. The following three typical cases are considered:1)the desorption of one kind of reagents, 2)the random distribution of inert sites on the lattice, 3) both 1) and 2) together. The conclusions are drawn as follows: the desorption makes more lattice sites empty, and thus the reaction can continually take place. The bigger the desorption rate the wider the reaction window. On the contrary, the presence of the inert site impedes the adsorption of reagent and decreases the reaction, and the reaction window narrows. When the concentration of the inert site p i reaches a critical value, a large cluster of non inert sites is hardly formed and the reaction window disappears finally.