Magnetism in Mn and Co doped ZnO bulk samples

Bulk samples with nominal composition Zn0.95Co0.05O and Zn0.92Co0.05Mn0.03O were fabricated by a solid-state reaction method at 600℃.X-ray diffraction experiment showed that the peaks of secondary phase Co3O4 with a cubic structure were visible in both samples,besides the main peaks of wurtzite structure as ZnO.Magnetization measurement indicated that doping Co alone can induce ferromag- netism in ZnO itself,while the introduction of Mn significantly enhances ferromagnetism.However, both samples showed different magnetic behavior at temperatures below 50 K.It was also noted that ferromagnetic coupling interaction was weakened due to the presence of antiferromagnetic Co3O4.     

Features of the EAP events on the medium-range evolution process and the mid- and high-latitude Rossby wave activities during the Meiyu period

In this paper, features for the evolution of the East Asia/Pacific （EAP） events and their association with high- and mid-latitude Rossby waves during the Meiyu period are analyzed on the medium-range time scale, it is shown that life cycles of the positive and negative EAP events cannot be simply regarded as ＂mirror＂ each other. In the upper troposphere, downward propagations of Rossby wave packets both over high- and mid-latitude regions of Eurasian continent and over the Asian jet region are responsible for generating basic patterns of high- and mid-latitude anomaly centers of the events. In this layer, Rossby wave packets also propagate from the mid-latitude anomaly center to the high-latitude one. In the middle and lower troposphere, the formation of the subtropical anomaly center of the event is mainly attributed to the anomalous convective activity in the tropical Pacific warm pool. The northward Rossby wave energy dispersion from this center is favorable to the enhancement and maintenance of the mid-latitude anomaly center in the same layer. Finally, it might be hypothesized that typical features of the positive and negative EAP events in their mature phase result from the interaction between （or phase-locking of） respective anomalous circulations induced both by quasi-zonal Rossby wave packets embedded in upper troposphere westerly and by quasi-meridional Rossby wave packets in the background flow of the East Asian summer monsoon in the middle and lower troposphere.