Cs蒸气中的碰撞能量合并和6P3/2和6P1/2间的激发转移

通过激发转移和碰撞能量合并研究了Cs(62P)精细结构混合.单模半导体激光器激发基态Cs原子至6P3/2态,直接荧光是由6P3/2态发射的,敏化荧光是由精细结构碰撞转移和碰撞能量合并产生的.由相对荧光强度得到了转移截面σ(6P3/2→6P1/2)=(1.5±0.5)×10-15cm2,与其它实验结果进行了比较.     

Structure Characterization of HSQ Films for Low Dielectrics Using D5 as Sacrificial Porous Materials

Low-density materials, commercially available hydrogensilsesquioxane （HSQ） offer a low dielectric constant. HSQ films can be obtained by spin on deposition （SOD）. In this work, low-dielectric-constant HSQ films are prepared by using D5 （decamethylcyclopentasiloxane） as sacrificiaJ porous materials. The dielectric constant of silica films significantly changes from 3.0 to 2.4. We report the structural aspects of the films in relation to their composition after annealed at 300℃, 400℃, and 500℃ for 1.5h in nitrogen ambient and annealed at 400℃ for 1.5h in vacuum. Si-OH appears after annealed at 400℃ for 1.5h in vacuum. The results indicate that the proper condition is in nitrogen ambient. Intensity of the Sill peak increases with the increasing temperature. Fourier transform infrared spectroscopy is used to identify the network structure and cage structure of Si-O-Si bonds and other possible bonds. Dielectric constant k is significantly lowered by annealing at 350℃ for 1.5h in nitrogen ambient. The I-V and C-V measurements are used to determine the dielectric constant, the electric resistivity and the breakdown electric field.     

Na2（B^1Πu）＋Na（3S）碰撞能量转移

用532.0nm激光激发Na2分子到B1∏u电子态,记录了Na原子的跃迁和Na2分子的A1∑+u-X1∑+g的谱带.由Na与Na2激发态发射的光谱及其强度可以认定在Na-Na2系统中的碰撞过程,Na原子线是Na2(B1∏u)到Na(3P)的碰撞能量转移产生的,预解离过程也可产生原子线.而A1∑+u-X1∑+g谱带是由B1∏u到21∑+g的碰撞转移后再由21∑+g到A1∑+u的辐射而引起的.在360C,根据辐射衰变率和荧光强度,得到Na2(B1∏u)到Na2(21∑+g)碰撞转移速率系数为7.1×10-10cm3s-,而B1∏u的预解离率为2.3×106s-.对不同振动能级间的碰撞激发转移[Na2(B1∏u)(v′=6)+Na(3S)→Na2(B1∏u)(v′=5,7)+Na(3S)]也进行了研究,并得到了v′=5和7时的速率系数分别是1.3×10-10cm3s-1和1.1×10-10cm3s-1.