排序方式: 共有13条查询结果,搜索用时 15 毫秒
11.
在计算对称区间上的定积分和对称区域上的重积分时,适当利用积分区域和被积函数的对称性可起到简化计算的作用.同样,在曲线积分和曲面积分的计算中,也可利用对称性简化计算. 相似文献
12.
To design and calculate the zero-dispersion wavelength is one of the important aspects for highly nonlinear photonic crystal fibres. By using the air filling fraction f defined as f = ( 6d) / ( 2π∧ ) here for the cladding effective index, and the step effective index model, the relationship between the properties of chromatic dispersion and the two different structures has been analysed. It is pointed that the variation of the zero dispersion wavelength is insensitive to the core diameter change in one range of core diameter D, while keeping the air filling fraction f constant. In the other range of core diameter D, the photonic crystal fibres have the best nearly-zero ultraflattened dispersion. These properties are significant to the design of chromatic dispersion and zero dispersion wavelength in photonic crystal fibres. 相似文献
13.