Martingale Musielak-Orlicz Hardy spaces

In this article,we introduce the martingale Musielak-Orlicz Hardy spaces H_φ~*(?),Pφ(?),H_φ~S(?),Qφ(?)and H_φ~s(?),respectively,via the maximal function,the quadratic variation and the conditional quadratic variation of martingales.We then establish the atomic characterizations of H_φ~s(?),Pφ(?)and Qφ(?).As applications,we obtain the dual space of H_φ~s(?)and several martingale inequalities which further clarify the relations among H_φ~*(?),Pφ(?),H_φ~S(?),Qφ(?)and H_φ~s(?).Especially,as special cases,the results on atomic characterizations of H_φ~s(?),Pφ(?)and Qφ(?)as well as on the dual space of H_φ~s(?)in the weighted case are also new.     

Strain characteristics and superelastic response of single crystals

The intermartensitic transformation, in a two-step complete thermoelastic martensitic transformation in Ni_53.2Mn_22.6Ga_24.2 single crystals, provides a much larger strain than that of the martensitic transformation. With a biasing magnetic field, the intermartensitic transformation strain is inhibited and the martensitic transformation strain is enhanced. Compressive stress–strain characteristics can be affected greatly by a static magnetic field. At low deformation temperature, the irreversible transformation strain induced by the stress becomes reversible, when a static magnetic field is applied. Further, the magnitude of the stress necessary for rearrangement of martensitic variants is dependent on the direction of the biasing magnetic field. Moreover, a well-defined character of the twin-boundary motion, similar to the soliton motion, has been observed upon loading or unloading.     

Proof of class number formulae by machine

As an attempt to follow the direction of machine proof, a personal computer LE0386/25 is used to prove some class number formulae for certain imaginary quadratic number fields ,q=3, 7, 11, 19, 23, 31, 43 and 47) if the real quadratic number field has class number one for a primep = 4N ² + 1 (N is a positive integer). Project supported by the National Natural Science Foundation of China.     

实循环矩阵与实对角矩阵相似问题

本文中我们证明了与实对角矩阵相似的每一个实循环矩阵都是对称的．并给出了一个正交变换，使得任意的ｎ×ｎ实循环对称矩阵通过该变换与实对角矩阵相似．     

Magnetism and Hall effect of the Heusler alloy Co2ZrSn synthesized by melt-spinning process

Magnetization and Hall resistivity have been measured for the Heusler alloy Co₂ZrSn synthesized by the melt-spinning process. The temperature dependence of magnetization follows the spin-wave theory at a low temperature. Abnormal behaviors are observed both in resistance and Hall effect below 8 K. The present Hall resistivity measurement shows that the anomalous Hall effects coexist with normal Hall effects. The negative value of normal Hall coefficient over the whole temperature range reveals that the major charge carriers are electrons. The anomalous Hall coefficient is proportional to the zero-field resistivity, suggesting that magnetic skew scattering is the dominant mechanism in the ferromagnetic regime. The reason for the abnormity below 8 K during transport is discussed.     

High spin polarization in ordered Cr3Co with the DO3 structure: A first-principles study

The electronic structure of the highly ordered alloy Cr₃Co with the DO₃ structure has been studied by FLAPW calculations. It is found that the ferrimagnetic state is stable and that the equilibrium lattice constant of Cr₃Co equals 5.77 Å. A large peak in majority spin density of states (DOS) and an energy gap in minority spin DOS are observed at the Fermi level, which results in a high spin polarization of 90% in the ordered alloy Cr₃Co. The total magnetic moment of Cr₃Co is 3.12μ_B, which is close to the ideal value of 3μ_B derived from the Slater-Pauling curve. An antiparallel alignment between the moments on the Cr (A, C) sites and the Cr (B) sites is observed. Finally, the effect of lattice distortion on the electronic structure and on magnetic properties of Cr₃Co compound is studied. A spin polarization higher than 80% can be obtained between 5.55 and 5.90 Å. With increasing lattice constant, the magnetic moments on the (A, C) sites increase and the moments on the (B, D) sites decrease. They compensate each other and make the total magnetic moment change only slightly.     

Effect of Fe substitution on the magnetic properties of half-Heusler alloy CoCrAl

The effect of Fe substitution for the vacant site in half-Heusler alloy CoCrAl is studied. A series of single phase CoFe_xCrAl (x=0.0, 0.25, 0.5, 0.75 and 1.0) alloys has been successfully synthesized. The lattice constant is found to increase almost linearly with increasing Fe content, indicating Fe atoms enter the lattice of CoCrAl instead of existing as a secondary phase. When Fe entering the vacant site, spin polarization occurs and the alloy turns from a semimetal in CoCrAl to a half-metallic ferromagnet (HMF) in CoFeCrAl. This is due to the reconstruction of the energy band with Fe substitution. The Curie temperature and saturation magnetic moments are enhanced and increase monotonically with increasing Fe content. The variation of the spin moment follows the Slater-Pauling curve and agrees with the theoretical calculation as well.     

预测三元系超额焓的一种新方法

提出一种预测三元系超额焓的新方法。该方法利用改进的立方状态方程－－ＦＲＫＳ方程，并以二元互作用参数函数代替单一数值的二地互作用参数，为计算体系提供随状态变化的二元互作用参数数值。对十二个非理想三元系及其组分二元素的计算结果表明，该方法明显提高了二元系超额焓的拟合精度，从而在不引入任何三元参数的条件下较好地改进了三元系超额焓的预测。     

高压下二元系超额体积的拟合

利用F函数改进的立方状态方程—FRKS方程,并在二元互作用函数中引入压力项因子,对高压下二元系的超额体积进行拟合。压力项因子的引入,使得该方法能够适用于温度、压力变化的体系。对十个高压下的二元系的拟合结果表明,该方法能给出较好的拟合结果。