高温超导体中不同临界态模型下的磁弛豫

基于Anderson-Kim临界态模型,考虑涡旋玻璃态模型和集体磁通蠕动理论以及考虑磁通线反跳的热激活模型等目前几种关于高温超导体中磁弛豫现象的理论模型,推导出弛豫率和约化弛豫率的理论计算公式并在此基础上分析各个理论模型下弛豫率和约化弛豫率的理论计算结果和实验数据之间的关系,对各个理论模型的适用范围进行分析和比较.     

各向同性Nd-Fe-B复合塑料磁性材料的研究

研究了粒度为2～10μm的烧结Nd-Fe-B微粉与聚丙烯复合制成的模压磁体的磁性能与磁粉填充率、粒度和成型压力的关系。磁体的最大磁能积为16kJ/m~3,自然条件下短期剩余磁通的不可逆损失不超过1％。     

两带各向异性超导体的磁通量子化——以MgB2为例

以MgB2为例，用两带各向异性Ginzburg-Landau理论分析了两能隙超导体的磁通量子化现象，总的来说，两能隙超导环内的磁通是磁通量子的整数倍，两带对应的磁通线根数相同，且一根σ带磁通线与一根π带磁通线所携带的磁通之和为一个磁通量子。     

层状超导体磁通格子固相熔化的温度效应

发展了层状超导体中3D磁通线模型,用动力学模拟方法数值研究了磁通格子的有序-无序熔化相变.在无序强度温度相图中,发现从有序的布拉格玻璃相到无序的磁通玻璃相之间的固-固相变线在中等温度区域有一个突起,与最近实验上得到的"反向熔化"现象一致.这一反向熔化行为起因于磁通之间相互作用的异常温度效应.     

四端介观量子网络中电子自旋的相干输运性质

采用解线性方程组的方法,研究了存在磁通时,四端介观量子网络中电子自旋的相干输运性质。该四端网络由具有Rashba自旋-轨道耦合互作用的量子线构成,数值计算了自旋电导对约化磁通和自旋-轨道耦合强度的依赖关系。计算结果表明:该网络中的自旋相干输运性质由约化磁通和Rashba自旋-轨道耦合之间的相互作用共同决定。这种结构中,一些端可以作为栅极控制其他端的自旋流,该四端多通道网络结构为调控电子自旋的相干输运提供了更多的选择。     

半导体纳米环中激子的磁场效应

在有效质量近似下,采用矩阵对角化方法,研究了半导体纳米环中激子的磁场效应.研究发现半导体纳米环中激子的谐振子强度随磁通变化呈现Aharonov-Bohm振荡,振子强度的振幅随纳米环的半径增加而减少.讨论了线性、三阶非线性和总光学吸收系数随环半径和磁通的变化关系,结果表示半导体纳米环中激子的光吸收随磁通的变化显示Aharonov-Bohm效应.     

半导体纳米环中激子的磁场效应（英文）

在有效质量近似下,采用矩阵对角化方法,研究了半导体纳米环中激子的磁场效应.研究发现半导体纳米环中激子的谐振子强度随磁通变化呈现Aharonov-Bohm振荡,振子强度的振幅随纳米环的半径增加而减少.讨论了线性、三阶非线性和总光学吸收系数随环半径和磁通的变化关系,结果表示半导体纳米环中激子的光吸收随磁通的变化显示Aharonov-Bohm效应.     

Bi2Sr2Ca1—xPrxCu2Oy单晶的穿透深度和钉扎行为

系统研究了Ｐｒ掺杂对Ｂｉ２Ｓｒ２Ｃａ１－ｘＰｒｘＣｕ２Ｏｒ单晶的穿透深度和钉扎行为的影响。发现Ｐｒ散射使低温下穿透深度的温度依赖关系从线性行为转变为平方为,有力地支持了超导序参量的ｄ波对称性;Ｐｒ掺杂使ＣｕＯ层间耦合减弱,不可逆场向低场方向移动,不可逆线起源于涡旋线的脱钉。     

Hg系新高Tc超导体研究

我们制备了新高Ｔｃ Ｈｇ－Ｂａ－Ｃａ－Ｃｕ超导氧化物系,并用Ｘ－ｒａｙ衍射、ＴＥＭ、磁化率及电阻等实验测量对它们进行了研究。由ＴＥＭ观察,证实了在ＨＢＣＣＯ系中存在Ｈｇ－１２０１相,Ｈｇ－１２１２相和Ｈｇ－１２２３相。用高－Ｑ振动子技术,对ＨｇＢａ２ＣｕＯ４＋ｙ样品作了与磁通点阵运动有关的力学测量,从而估计出该样品的不可逆线的形状。我们还对Ｈｇ－１２２３样品作了事后退火处理研究,在氧气中退火可使该     

Qα△(T~n)时两源不可逆热机的基本优化关系

本文在给定内不可逆性的基础上,研究了Qa△(T~n)时,两种循环工况下不可逆卡诺循环的输出功率与效率间的基本优化关系。结果表明与内可逆卡诺循环有相同吸、放热时间的不可逆卡诺循环的优化关系最佳;讨论说明这一优化关系是线性、非线性传热,内可逆与内不可逆多种情况满足的普遍关系。     

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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-