(2+1)-dimensional dissipation nonlinear Schrödinger equation for envelope Rossby solitary waves and chirp effect

In the past few decades, the (1+1)-dimensional nonlinear Schrödinger (NLS) equation had been derived for envelope Rossby solitary waves in a line by employing the perturbation expansion method. But, with the development of theory, we note that the (1+1)-dimensional model cannot reflect the evolution of envelope Rossby solitary waves in a plane. In this paper, by constructing a new (2+1)-dimensional multiscale transform, we derive the (2+1)-dimensional dissipation nonlinear Schrödinger equation (DNLS) to describe envelope Rossby solitary waves under the influence of dissipation which propagate in a plane. Especially, the previous researches about envelope Rossby solitary waves were established in the zonal area and could not be applied directly to the spherical earth, while we adopt the plane polar coordinate and overcome the problem. By theoretical analyses, the conservation laws of (2+1)-dimensional envelope Rossby solitary waves as well as their variation under the influence of dissipation are studied. Finally, the one-soliton and two-soliton solutions of the (2+1)-dimensional NLS equation are obtained with the Hirota method. Based on these solutions, by virtue of the chirp concept from fiber soliton communication, the chirp effect of envelope Rossby solitary waves is discussed, and the related impact factors of the chirp effect are given.     

单壁碳纳米管弹性性质的羟基接枝效应

用分子动力学方法研究了端口接枝不同数量羟基对扶手椅型和锯齿型单壁碳纳米管弹性模量的影响.结果表明,未接枝的扶手椅型(5, 5),(10,10)管和锯齿型(9, 0),(18, 0)管杨氏模量分别为948,901和804,860GPa.在接枝2—8个羟基情况下,锯齿型单壁碳纳米管拉伸杨氏模量基本不随接枝数量增加发生变化,而扶手椅单壁碳纳米管则不同,接枝状态下的弹性模量比未接枝状态小很多,但接枝一定数量后,其杨氏模量又略增到某一稳定值.分别从接枝后碳纳米管变形电子密度等值线结构、C—C键长和系统结合能变化规律等方面,对单壁碳纳米管弹性模量的接枝效应进行了分析. 关键词： 碳纳米管 羟基 接枝效应 杨氏模量     

Cr3+掺杂的Cd3 Al2 Ge3O12光谱特性及晶场参数计算

采用高温固相法合成了Cd3Al2 Ge3O12Cr3 多晶材料,利用X射线衍射对其结构进行了分析,通过Cr3 的室温吸收光谱、室温和77 K发射光谱分别对其光谱特性和晶场参数进行了分析和计算.结果表明:在450 nm的蓝光激发下,Cd3Al2 Ge3O3 室温发射光谱主要由三个宽带及附加其上的弱R线构成,分别对应于C3 的4T1,T2,2T2,4T2到4A2能级跃迁.低温时宽带发射变弱,而R线变得强而锐.Cr3 在Cd3Al2Ge3O12中晶场强度Dq/B为2.32,Stokes位移AE,为1919 cm1,黄昆-里斯因子S为5.58.表明在Cd3Al2Ge3O12中Cr3 处于弱的中等晶场强度,电子-声子耦合较强.4T2零声子能级与2能级的间距△E仅为325.5 cm-1,对Cr3 可调谐激光的输出非常有利.     

Cr3+掺杂的Cd3Al2Ge3O12光谱特性及晶场参数计算

采用高温固相法合成了Cd₃Al₂Ge₃O₁₂：Cr³⁺多晶材料,利用X射线衍射对其结构进行了分析,通过Cr³⁺的室温吸收光谱、室温和77K发射光谱分别对其光谱特性和晶场参数进行了分析和计算.结果表明：在450 nm的蓝光激发下,Cd₃Al₂Ge₃O₁₂：Cr³⁺室温发 关键词： 3Al₂Ge₃O₁₂：Cr³⁺')" href="#">Cd₃Al₂Ge₃O₁₂：Cr³⁺ 荧光光谱 晶场参数 可调谐激光