Trace of B and Ga can substitute for Mo in Mn-Si-Cr dual phase steels.The technological process and CCT curves of steels treated with B and Ga are similar to those for Mn-Si-Cr-Mo steel.
This review summarizes the recent advances on the application of ^(57)Fe Mössbauer spectrometry to study the magnetic and phase characteristics of Nd–Fe–B-based permanent magnets. First of all, the hyperfine st...This review summarizes the recent advances on the application of ^(57)Fe Mössbauer spectrometry to study the magnetic and phase characteristics of Nd–Fe–B-based permanent magnets. First of all, the hyperfine structures of the Ce_(2)Fe_(14)B,(Ce,Nd)_(2)Fe_(14)B and MM_(2)Fe_(14)B phases are well-defined by using the model based on the Wigner-Seitz analysis of the crystal structure. The results show that the isomer shift δ and the quadrupole splitting öEQ of those 2:14:1 phases show minor changes with the Nd content, while the hyperfine field Bhfincreases monotonically with increasing Nd content and its value is influenced by the element segregation and phase separation in the 2:14:1 phase. Then, the hyperfine structures of the low fraction secondary phases are determined by the ^(57)Fe Mössbauer spectrometry due to its high sensitivity. On this basis,the content, magnetic behavior, and magnetization of the REFe_(2) phase, the amorphous grain boundary(GB) phase, and the amorphous worm-like phase, as well as their effects on the magnetic properties, are systematically studied.展开更多
针对BOTDR分布式光纤传感技术中背向散射光中布里渊散射信号光的分离提取问题,设计了一种高消光比双通道可调M-Z干涉仪,该干涉仪由两个3 d B耦合器、电动光纤延迟线、偏振控制器及光隔离器构成。使用C波段宽带光源(ASE)对M-Z干涉仪性能...针对BOTDR分布式光纤传感技术中背向散射光中布里渊散射信号光的分离提取问题,设计了一种高消光比双通道可调M-Z干涉仪,该干涉仪由两个3 d B耦合器、电动光纤延迟线、偏振控制器及光隔离器构成。使用C波段宽带光源(ASE)对M-Z干涉仪性能进行了检测。并将脉宽为100 ns,重复频率为20 k Hz的脉冲光入射到长度为5 km的普通单模光纤中,将其产生的背向散射光经过M-Z干涉仪滤波后,通过光谱仪检测其输出的光谱信号。实验结果表明该干涉仪能够实现大范围高精度可调节滤波功能,对瑞利散射光的抑制超过20d B,可以有效地将背向散射光中的布里渊散射光信号分离提取出来。展开更多
文摘Trace of B and Ga can substitute for Mo in Mn-Si-Cr dual phase steels.The technological process and CCT curves of steels treated with B and Ga are similar to those for Mn-Si-Cr-Mo steel.
基金Project supported by the Zhejiang Provincial Natural Science Foundation of China(Grant Nos.LY20E010002,LR18E010001,and LD19E010001)the National Natural Science Foundation of China(Grant Nos.U1704253 and 51801047)+2 种基金Liaoning Revitalization Talents Program(Grant No.XLYC1807177)the Key Research and Development plan of Zhejiang Province,China(Grant No.2020C05014)Ten Thousand Talents Plan of Zhejiang Province,China(Grant No.2018R52003)。
文摘This review summarizes the recent advances on the application of ^(57)Fe Mössbauer spectrometry to study the magnetic and phase characteristics of Nd–Fe–B-based permanent magnets. First of all, the hyperfine structures of the Ce_(2)Fe_(14)B,(Ce,Nd)_(2)Fe_(14)B and MM_(2)Fe_(14)B phases are well-defined by using the model based on the Wigner-Seitz analysis of the crystal structure. The results show that the isomer shift δ and the quadrupole splitting öEQ of those 2:14:1 phases show minor changes with the Nd content, while the hyperfine field Bhfincreases monotonically with increasing Nd content and its value is influenced by the element segregation and phase separation in the 2:14:1 phase. Then, the hyperfine structures of the low fraction secondary phases are determined by the ^(57)Fe Mössbauer spectrometry due to its high sensitivity. On this basis,the content, magnetic behavior, and magnetization of the REFe_(2) phase, the amorphous grain boundary(GB) phase, and the amorphous worm-like phase, as well as their effects on the magnetic properties, are systematically studied.
文摘针对BOTDR分布式光纤传感技术中背向散射光中布里渊散射信号光的分离提取问题,设计了一种高消光比双通道可调M-Z干涉仪,该干涉仪由两个3 d B耦合器、电动光纤延迟线、偏振控制器及光隔离器构成。使用C波段宽带光源(ASE)对M-Z干涉仪性能进行了检测。并将脉宽为100 ns,重复频率为20 k Hz的脉冲光入射到长度为5 km的普通单模光纤中,将其产生的背向散射光经过M-Z干涉仪滤波后,通过光谱仪检测其输出的光谱信号。实验结果表明该干涉仪能够实现大范围高精度可调节滤波功能,对瑞利散射光的抑制超过20d B,可以有效地将背向散射光中的布里渊散射光信号分离提取出来。
