The structure and intrinsic magnetic properties of RFeM(M=V or Ti),type 1:12,have been studied by magnetic measurement and X-ray diffraction.They are body-centered tetragonal ThMn_(12)structure.The changes of crystal ...The structure and intrinsic magnetic properties of RFeM(M=V or Ti),type 1:12,have been studied by magnetic measurement and X-ray diffraction.They are body-centered tetragonal ThMn_(12)structure.The changes of crystal lattice constants coincide with that of their element radii.Curie temperature is decided mainly by the exchange interactions of 3d-3d and 3d-4f atom pairs.The data obtained by mean-field approximation agree well with experimental values.The magnetic moment coupling in these compounds for LRE is ferromagnetic,and for HRE is antiferromagnetic.At low temperature,anisotropy field is decided by RE sublattice.In this paper,the influence of magnetic properties of cobalt and nickel replacing iron has also been studied.展开更多
全变分(Total Variation,TV)变换作为一种常用的稀疏变换模型,因其在保持图像边缘信息方面具有明显的优势,已经被应用到图像去噪问题中。然而,它通常会产生阶梯伪影。为了克服这个缺点,在该文中,我们引入交叠组合稀疏全变分(Overlapping...全变分(Total Variation,TV)变换作为一种常用的稀疏变换模型,因其在保持图像边缘信息方面具有明显的优势,已经被应用到图像去噪问题中。然而,它通常会产生阶梯伪影。为了克服这个缺点,在该文中,我们引入交叠组合稀疏全变分(Overlapping Group Sparsity Total Variation,OGSTV)代替传统TV变换模型。为了求解该OGSTV去噪模型,我们提出一种基于快速傅里叶变换(Fast Fourier Transform,FFT)和split Bregman算法的快速OGSTV去噪方法。实验结果表明,引入快速傅里叶变换理论后,图像去噪时间明显减少;与其他已有比较好的算法相比,可以获得更好的图像质量,阶梯效应明显改善。展开更多
基金This work is supported in part by the Magnetics Open Laboratory of Academia Sinica.
文摘The structure and intrinsic magnetic properties of RFeM(M=V or Ti),type 1:12,have been studied by magnetic measurement and X-ray diffraction.They are body-centered tetragonal ThMn_(12)structure.The changes of crystal lattice constants coincide with that of their element radii.Curie temperature is decided mainly by the exchange interactions of 3d-3d and 3d-4f atom pairs.The data obtained by mean-field approximation agree well with experimental values.The magnetic moment coupling in these compounds for LRE is ferromagnetic,and for HRE is antiferromagnetic.At low temperature,anisotropy field is decided by RE sublattice.In this paper,the influence of magnetic properties of cobalt and nickel replacing iron has also been studied.
文摘全变分(Total Variation,TV)变换作为一种常用的稀疏变换模型,因其在保持图像边缘信息方面具有明显的优势,已经被应用到图像去噪问题中。然而,它通常会产生阶梯伪影。为了克服这个缺点,在该文中,我们引入交叠组合稀疏全变分(Overlapping Group Sparsity Total Variation,OGSTV)代替传统TV变换模型。为了求解该OGSTV去噪模型,我们提出一种基于快速傅里叶变换(Fast Fourier Transform,FFT)和split Bregman算法的快速OGSTV去噪方法。实验结果表明,引入快速傅里叶变换理论后,图像去噪时间明显减少;与其他已有比较好的算法相比,可以获得更好的图像质量,阶梯效应明显改善。
