血红素LB膜的电化学行为

采用循环伏安法研究了血红素与脑磷脂混合Y型LB（Langmuir-Blodgett）膜在玻碳电极上的电化学行为，结果表明血红素LB膜有良好的电化学活性，在0．1mol/L KCl溶液中有一对氧化还原峰（－0．42V／－0．30V）；将血红素LB膜转移到玻碳电极表面得到的血红素LB膜修饰电极（heme LB-GC）对溶液中溶解氧的电化学还原有良好的催化作用，其催化还原过程具有不可逆电荷传递特性。     

酸度及溶剂极性对两亲配体紫外-可见光谱的影响

研究了溶剂生和溶液的酸度对两亲配体Ｎ－十六烷基－８－羟基－２－喹啉甲酰胺（ＨＬ）紫外－可见光谱的影响。在碱性介质中,ＨＬ的吸收带＾１Ｂｂ、＾１Ｌａ和＾１Ｌｂ均产生红移;在酸性介质中,ＨＬ的吸收带不仅红移,而且＾１Ｌｂ带分开明为两个吸收峰。ＨＬ存在明显的浓度效应。非极性和弱极性溶剂对ＨＬ的紫餐可见光谱的影响服从Ｂａｙｌｉｃｓ方程;极性溶剂对ＨＬ的紫外可见光谱的影响服从ＭｃＲａｃ方程。     

Origin of diffraction fringes in two-dimensional photoelectron momentum distributions for single ionization of atoms in few-cycle intense laser pulses

We use the strong field approximation with a time window function controlling the release time of electrons to study the intra-cycle and inter-cycle interferences in few-cycle intense laser pulses impinging on He. The diffraction fringes, i.e., the vertical stripe-like structure, observed in the experimental two-dimensional photoelectron momentum distributions of Gopal et al. （2009 Phys. Rev. Lett. 103 053001） have been attributed to the interplay of the intra- and inter-cycle interferences. The pure numerical calculations by solving the time-dependent Schrrdinger equation are also performed and the results are compared with the experimental measurements directly. It has been found that the position of the stripe-like structure can be used to determine the duration of the laser pulses used in experiments.     

等离子体中涡旋光束自聚焦与成丝现象的模拟研究

涡旋光束在低密度等离子体传输过程中出现的非线性物理效应与光子携带的轨道角动量(拓扑荷)存在密切关联.基于亥姆霍兹方程理论获得描述涡旋光束传输的旁轴近似方程,解析求出涡旋光束在低密度等离子体中传输的自聚焦临界功率表达式.利用分步傅里叶数值方法,针对不同参数条件下涡旋光束的自聚焦和成丝现象进行了模拟分析.研究结果表明,涡旋光束的拓扑荷数决定了自聚焦临界功率大小.涡旋光束发生成丝不稳定性现象的功率阈值和最大成丝数目与拓扑荷数存在密切关联.