单次碰撞条件下自由团蔟与小分子反应性的尺寸相关性

beam of tungsten clusters, seeded in He gas, is produced in a pulsed laser vaporization source. We have studied the size-dependent reactivity of positive tungsten cluster ions with N2 under single-collision-like conditions by using laser-vaporization source, low-pressure reaction cell and time-of-flight mass spectrometer. The reaction probability with N2 molecule was measured as a function of cluster size, W10+－W50+, for clusters produced at room temperature. There is a strong size-selectivity where the highest reaction probability S: 0.15~0.2 is measured for W16+, W22+ and W23+. There is a very good agreement, both in the size-variations and the absolute values, between the reactivity of neutral and cationic clusters. The second-harmonic generation(SHG) measurement of ZnSe at high pressure up to 7GPa has been reported. The Zinc blende-Rocksalt transition pressure has been determined at room temperature by SHG of ZnSe using femtosecond laser . The pressure required to induce transformation from a Zinc blende to Rocksalt decrease from 11.5 to 1.07GPa under femtosecond laser field. SHG can be used to monitor structural changes of some materials involves the nonlinear process of SHG under pressure.The structure and isomerization of acetone were studied by ab initio molecular orbital theory at B3LYP/6-31G(d,p) levels. Five isomeric equilibrium structures and eleven isomeric transition states were located. Isomerization paths for isomers were investigated by intrinsic reaction coordinate (IRC) calculations at B3LYP/6-31G(d,p)

建.立.和.完.善.用.于.自.由.团.簇.与.气.体.分.子.反.应.性.研究.的.实.验.装.置.，.在.单.次.碰.撞.条.件.下.研.究.各.种.自由.原.子.团.簇.与.气.体.分.子.之.间.的.反.应.性.，.及.其.与团.簇.尺.寸.的.相.关.性.。.利.用.激.光.脱.附.光.谱.详.细.研究.团.簇.与.吸.附.分.子.之.间.的.束.缚.能.和.激.发.态.团.簇内.部.的