磁性薄膜自旋波共振的量子力学研究

本文完全采用量子力学方法研究了体均匀铁磁性薄膜的自旋波共振激发，特别讨论了自旋波间的相互作用对共振谱的影响，在表面自旋完全钉扎的条件下，得到了三种共振激发谱。其中两种的共振谱大至呈现方律关系，但另一种谱吸收能量后从双波态向单波态跃迁，其强度迅速速衰减到最大强度的一半后保持不变，而共振峰的位置大致按照模数的平方增加。     

磁性双层膜中自旋波的波形及其演化

研究了磁性双层膜中自旋波的低能激发，着重地讨论了横向自旋波对纵向自旋波的波形的影响，发现了由于自旋波共振；ｉ）在能带中也存在界面模（ＩＭ），ｉｉ）在较高能带与较低能带相交的区域，随着γ值的增加，存在ＰＣＡＭ－ＰＣＢＭ振荡现象。     

三层不对称铁磁膜中的自旋波体模

本文研究了表面钉扎的Ａ、Ｂ、Ｃ三层不对称铁磁膜，利用界面重标度方法，求解了自旋波的低能量子本征问题．数值计算结果表明，当相邻层的界面处自旋波完全钉扎或近钉扎时．在Ｊ＿ｉＳ＿ｉ（ｉ＝Ａ、Ｂ、Ｃ）值较小的一层，发生自旋波的共振局域现象．     

铁磁薄膜的非局域磁化率张量和自旋波共振

基于具有表面磁各向异性的海森堡模型,运用格林函数方法研究了铁磁薄膜的磁化率张量和自旋波共振,证明了在一方向上失去平移不变性的铁磁薄膜具有非局域磁化率张量,采用非局域磁化率的表述方法推导出铁磁薄膜的表面各向异性与可被均匀微波磁场激发的自旋波模式的关系,给出了共振峰的位置和吸收强度的表达式,根据本文给出的理论公式,可用自旋波共振的实验方法测量铁磁体的表面各向异性.     

层间耦合对双层铁磁薄膜中自旋波共振禁闭模及共振的影响

对双层铁磁薄膜构成的系统，考虑界面铁磁性和反铁磁性耦合x寸自旋波色散关系、波形演化及共振的影响．结果表明：层间耦合对自旋波的共振影响较大，即层间铁磁性耦合比反铁磁性耦合更易发生共振．     

二维三组元局域共振磁振子晶体带隙结构的优化

采用平面波展开法,数值计算了二维三组元磁振子晶体的带结构、磁化强度场分布以及自旋波的态密度.研究表明,磁振子晶体带隙的产生机制为局域共振机制,而非布拉格散射机制,通过调节单散射体的共振结构,不仅能够使自旋波在低频范围内产生完全带隙,而且可实现自旋波带隙的优化.     

La0.67Ca0.33MnO3电子自旋共振线宽的自旋波理论

 采用固相反应法制备巨磁电阻材料La_0.67Ca_0.33MnO₃, 测试其电子自旋共振, 并采用自旋波理论解释自旋共振线宽的变化. 通过对自旋波能量的计算机自洽计算, 得到了自旋相互作用的重正化因子{1-e(T)/S}, 重正化因子随体系温度升高而降低表明,  温度上升导致自旋波频率发生软化现象, 使得体系结构不稳定, 由此可知实验未探测到相变区自旋波能量的原因.  理论计算表明, 自旋共振线宽随温度升高而减小是由于自旋波耦合模的数目减少所致.     

单轴各向异性下磁性薄膜自旋波共振频率

采用线性自旋波近似和格林函数方法,研究了外加磁场、单轴各向异性和表面各向异性场对磁性薄膜自旋波共振频率的影响。结果发现:系统自旋波共振频率随着外加磁场的增强而增大;表面各向异性场对能量较低两支模的频隙影响较大,而单轴各向异性则对能量最高和最低支模间的频隙影响较大     

单势垒量子阱中自旋抽运电流的研究

利用密度矩阵方法，我们研究了单势垒量子阱中自旋抽运电流，发现当量子阱中的电子发生自旋电子共振时．自旋抽运电流出现极大值。     

体单轴各向异性对双层铁磁薄膜中自旋波共振谱的影响

重点研究了双层铁磁薄膜系统在层间反铁磁耦合下,体单轴各向异性对自旋波色散关系和共振谱的影响.结果表明:随着体单轴各向异性常数的增加,各类型模之间相互转化;高能禁闭模共振减弱,低能禁闭模和界面模共振增强.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that