相变存储材料Ge1Sb2Te4和Ge2Sb2Te5薄膜的结构和电学特性研究

采用射频磁控溅射方法制备了两种用于相变存储器的Ge₁Sb₂Te₄和Ge₂Sb₂Te₅相变薄膜材料,对其结构、电学输运性质和恒温下电阻随时间的变化关系进行了比较和分析.X射线衍射(XRD)和原子力显微镜(AFM)的结果表明:随着退火温度的升高,Ge₁Sb₂Te₄薄膜逐步晶化,由非晶态转变为多晶态,表面出现均匀的、     

Sr掺杂Eu1-xSrxMnO3体系的磁相变以及输运特性研究

对Eu_1-xSr_xMnO₃ (ESMO, x=0—1)体系的结构和磁性进行了系统的研究,结果表明Sr的掺入使EuMnO₃反铁磁母体的磁结构发生巨大的变化.通过磁化和电输运测量,深入探讨了高掺杂浓度Eu_0.4Sr_0.6MnO₃和Eu_0.3Sr_0.7MnO_{3相似文献}   

Improvement in the calculation of anti-Stokes energy transfer and experimental justification based on Er0.01YbxY1 - 0.01 - xVO4 crystal

The improvement on the calculation of anti-Stokes energy transfer rate is studied in the present work. The additional proportion coefficient between Stokes and anti-Stokes light intensities of quantum Raman scattering theory as compared with the classical Raman theory is introduced to successfully describe the anti-Stokes energy transfer. The theoretical formula for the improvement on the calculation of anti-Stokes energy transfer rate is derived for the first time in this study. The correctness of introducing coefficient exp{ΔE / kT} from well-known Raman scatter theory is demonstrated also. Moreover, the experimental lifetime measurement in Er_0.01Yb_xY_{1 - 0.01 - x}VO₄ crystal is performed to justify the validity of our important improvement in the original phonon-assisted energy transfer theory for the first time.     

The relationship between the canonical ENSO and the phase transition of the Antarctic oscillation at the quasi-quadrennial timescale

A correlation analysis is performed to investigate the relationship between El Nino-Southern Oscillation (ENSO) and the Antarctic oscillation (AAO) at the quasi-quadrennial (QQ) timescale.It is found that the cold tongue index (CTI) and the AAO index (AAOI) are negatively correlated with about a 7-month lead-time,while they are positively correlated with about a 15-month lag-time.To further explore this relationship,complex empirical orthogonal function analysis is employed in the QQ sea level pressure (SLP) anomalies from 1951 to 2002.The results indicate that,during the ENSO cycle,there exists one kind of global tropical wave of wavenumber 1 (GTW1) propagating eastward.With the traveling of GTW1,the tropical SLP anomaly tends to intrude into the southern mid-latitudes.Accordingly,three strong signals travel synchronously along the circumSouth-Pacific path,and a relatively weak signal extends eastward and poleward over the South Ocean in the Atlantic-Indian Ocean sector.Following the propagation of these signals,the AAO phase tends to be reversed progressively.As a result,there exists an evident lead-lag correlation between CTI and AAOI.It can be concluded that ENSO plays a key role in the phase transition of AAO at the QQ timescale.It is also noticed that this regular relationship is only evident in the canonical ENSO events,for which sea surface temperature (SST) anomalies extend westward from the tropical eastern Pacific.On the other hand,the similar relationships are not found among those atypical ENSO events for which SST anomalies spread eastward from the central Pacific,such as the 1982-1983 ENSO event.     

Reconstructing tsunami run-up from the characteristics of tsunami deposits on the Thai Andaman Coast

Tsunamis can leave deposits on the land surface they inundate. The characteristics of tsunami deposits can be used to calculate tsunami run-up height and velocity. This paper presents a reconstruction of tsunami run-up from tsunami deposit characteristics in a simple mathematical model. The model is modified and applied to reconstruct tsunami run-ups at Ao Kheuy beach and Khuk Khak beach, Phangnga province, Thailand. The input parameters are grain-size and maximum run-up distance of the sediment. The reconstructed run-up heights are 4.16–4.91 m at Ao Kheuy beach and 5.43–9.46 m at Khuk Khak beach. The estimated run-up velocities (maximum velocity) at the still water level are 12.78–19.21 m/s. In the area located 70–140 m inland to the end of run-up inundation, estimated mean run-up velocities decrease from approximately 1.93 m/s to 0 m/s. Reasonably good agreements are found between reconstructed and observed run-up heights. The tsunami run-up height and velocity can be used for risk assessment and coastal development programs in the tsunami affected area. The results show that the area from 0 to 140 m inland was flooded by high velocity run-ups and those run-up energies were dissipated mainly in this area. The area should be designated as either an area where settlement is not permitted or an area where effective protection is provided, for example with flood barriers or forest.     

湘东桐木山云英岩型锡矿床锡石及共生石英中流体包裹体研究

桐木山云英岩型锡矿床是湘东锡田锡多金属矿田中一个典型矿床,在详尽的野外考察、矿石结构观察以及流体包裹体岩相学研究的基础上,采用流体包裹体组合的研究方法,利用冷热台、激光拉曼等测试手段,对矿床中锡石中流体包裹体进行直接测定,同时开展与锡石共生的石英及切割矿体的后期石英脉石英中流体包裹体对比研究.结果显示,锡石中流体包裹体...     

右江造山带北缘吴家坪组灰岩中卡林型金矿的发现及其意义——以贞丰县毛安、播老金矿为例

位于右江造山带北缘的毛安、播老等地,发现了上二叠统吴家坪组灰岩中的卡林型金矿,丰富了黔西南卡林型金矿的赋矿层位,本文从描述该类型金矿的矿床地质特征,分析了该类型金矿的成矿地质条件,探讨其地质意义,并对下步找矿提出建议,可供借鉴。     

从闪锌矿标型特征论台江龙井街铅锌矿成因

通过对闪锌矿的矿物共生组合,成分、形态及物理性质标型特征的研究,讨论了台江龙井街铅锌矿的成矿物质来源、成矿温度及成因类型。     

南召县石鼓金矿地质特征及成因探讨

石鼓金矿位于北秦岭复杂褶皱带东段,乔端-瓦穴子断裂南侧,牧虎顶花岗岩体之北侧,矿脉的产出受断裂构造控制.矿脉数量多,规模大小不一,成矿与构造岩浆活动等关系密切.矿床类型为石英脉型.     

广西大厂锡多金属矿床研究进展

大厂锡多金属矿床是世界闻名的超大型矿床,笔者从构造控矿、同位素测年、流体包裹体、成矿物质来源及同生沉积成矿等五个方面综述了近半个世纪来该矿床的一些研究进展,并结合近年来野外调查研究,认为大厂锡多金属矿床属后生成因,成岩、成矿是燕山晚期同一构造-热事件的产物,成矿过程中有幔源流体的显著参与,矿体产出形态的空间变化受不同深度的构造特征所控制。