In many situations such as the cores of a rotating electrical machine and the T joints of a multiphase transformer, the local flux density varies with time in terms of both magnitude and direction, i.e. the flux densi...In many situations such as the cores of a rotating electrical machine and the T joints of a multiphase transformer, the local flux density varies with time in terms of both magnitude and direction, i.e. the flux density vector is rotating. Therefore, the magnetic properties of the core materials under the rotating flux density vector excitation should be properly measured, modeled and applied in the design and analysis of these electromagnetic devices. This paper presents an extensive review on the development of techniques and apparatus for measuring the rotational core losses of soft magnetic materials based on the experiences of various researchers in the last hundred years.展开更多
Cloudy bands are typical stratigraphic structure in deep ice core. Detailed recording of cloudy bands is important for dating of ice core since pair of series cloudy band and clear layer is corresponds to annual layer...Cloudy bands are typical stratigraphic structure in deep ice core. Detailed recording of cloudy bands is important for dating of ice core since pair of series cloudy band and clear layer is corresponds to annual layer and it sometimes corresponds to volcanic ash layer. We developed two type scanners, transmitted light method and laser tomograph method for the stratigraphic study. Measurements were carried out for NGRIP deep ice core, which containing many cloudy bands, using the two type scanners and digital camera. We discussed about the possibility of identification of cloudy bands by each method and about advantage and disadvantage of measurements and their results.展开更多
文摘In many situations such as the cores of a rotating electrical machine and the T joints of a multiphase transformer, the local flux density varies with time in terms of both magnitude and direction, i.e. the flux density vector is rotating. Therefore, the magnetic properties of the core materials under the rotating flux density vector excitation should be properly measured, modeled and applied in the design and analysis of these electromagnetic devices. This paper presents an extensive review on the development of techniques and apparatus for measuring the rotational core losses of soft magnetic materials based on the experiences of various researchers in the last hundred years.
文摘Cloudy bands are typical stratigraphic structure in deep ice core. Detailed recording of cloudy bands is important for dating of ice core since pair of series cloudy band and clear layer is corresponds to annual layer and it sometimes corresponds to volcanic ash layer. We developed two type scanners, transmitted light method and laser tomograph method for the stratigraphic study. Measurements were carried out for NGRIP deep ice core, which containing many cloudy bands, using the two type scanners and digital camera. We discussed about the possibility of identification of cloudy bands by each method and about advantage and disadvantage of measurements and their results.
