霍尔效应对磁场作用下电化学分形沉积物形貌的影响

运用霍尔效应的原理,分析了在磁场中电化学分形沉积物形貌与无外加磁场时电化学沉积物正常生长分形明显不同的原因,解释了分形沉积物形貌变化与外加磁场的方向、强度之间的关系,半定量分析了霍尔效应对电化学分形沉积的影响程度.研究结果表明:当无外加磁场时,在分形沉积物分枝上只存在平行于分枝的正向电压;当存在外加磁场时,因为霍尔效应,在分形沉积物分枝上,除了存在平行于分枝的正向电压外还存在垂直于分枝的切向电压,使后继的形核和生长在分枝的低电位侧占优势,这是造成沉积物形貌改变的重要原因.     

霍尔效应法测量磁场实验的研究

介绍了霍尔效应及其副效应;分析霍尔效应法测磁场的误差来源;给出异常数据的处理方法.     

钉扎在高温超导体反常霍尔效应中的作用

研究了钉扎在高温超导体反常霍尔效应中的作用。将从Ginzburg-Landau(GL) 理论出发推导出的扩展幂律方程应用到高温超导体霍尔效应中, 并详细考虑钉扎效应, 得到了霍尔电阻在低温低场端分别关于温度和磁场的两个标度律, 不同高温超导体的实验数据可以很好地标度在一起。同时, 基于含时GL理论的结果并考虑钉扎效应,给出了一组描述存在一次或多次霍尔反号的高温超导体的霍尔电导方程。     

用霍尔效应实验仪测量周围环境磁场的探究

在原霍尔效应实验的基础上,运用磁场叠加原理,提出用作差法和电位调零法来测量霍尔电压,这两种方法不仅能够消除不等位电势差与环境因素对霍尔效应实验的影响,还能够很好地测量外界环境磁场在霍尔片所在位置处的磁感应强度的大小.     

对霍尔效应测量磁场实验的方法改进

针对大学物理实验中"霍尔效应法测量磁场"项目只能测长直螺线管轴线上的磁场分布的不足,提出一种改进方法,测量任一未知磁场在二维空间中的分布,进而可扩展到测量三维空间磁场的分布。经改进后的实验可使学生深刻理解霍尔效应测磁场的原理及磁场的性质,并可作为设计性实验项目在大学物理实验课中开出,培养学生的创新意识。     

基于霍尔效应的流体介质流量测量的方法

探讨流体介质在磁场中产生霍尔效应的原理过程,论证利用该效应测量流量的可能性及应用条件,给出了相应的理论公式及模拟实验模型与结果     

用霍尔效应测螺线管内磁场的实验条件

对影响用霍尔效应测螺绕管内磁场分布实验的因素及实验条件进行了讨论。认为在同一定大小的磁场时，选用较小的工作电流有利于提高实验的质量。     

霍尔效应

量子反常霍尔效应是我国科学家从该实验上独立观测到的一个重要物理现象,也是世界基础研究领域的一项重要科学发现.这是在美国物理学家霍尔于1880年发现霍尔效应133年后终于实现了反常霍尔效应的量子化,是我国科学家从实验上独立观测到的一个重要物理现象,也是世界基础研究领域的一项重要科学发现.该文将详细讲解霍尔效应的发展历史.     

圆盘形双层膜系统中的交变逆自旋霍尔效应

以铁磁体Py与顺磁金属Pt构成的圆盘形双层膜系统为研究对象,在垂直于界面的磁化建立后,沿盘面的激发场可以泵浦自旋流从铁磁体进入顺磁金属,由于逆自旋霍尔效应,发现系统中不存在直流电压,只存在交流电压。通过沿不同方向的测量可以区分逆自旋霍尔效应诱致的交流电压和激发磁场自身诱致的交流电压。计算了逆自旋霍尔效应诱致的交流电压大小和激发磁场自身诱致的交流电压大小对外磁场的依赖性,发现在铁磁共振时,逆自旋霍尔效应诱致的交流电压大小达到最大,而偏离共振磁场后,交流电压大小很快衰减;而激发磁场自身诱致的交流电压大小随外磁场的增大而增加。其次,研究了在不同位相差下,在垂直于激发场方向总的交流电压大小对外磁场的依赖性,发现交流电压大小随着两者之间相位差的变化在共振点附近变化很明显;进一步在共振点附近,计算了总的交流电压大小对相位差的依赖性,发现相位为0时,交流电压达到最大;而相位为π时,交流电压达到最小。最后,文章还计算了交流电压大小对激发功率的依赖性,发现不同于直流电压与激发功率P成正比的情况,两种类型的交流电压都与P~(1/2)成正比。     

量子化反常霍尔效应及其研究进展

量子反常霍尔效应是在没有外磁场的情况下由自发磁化导致的量子化霍尔电导效应,其物理本质是自发磁化和自旋轨道耦合相互作用共同导致的拓扑非平庸的电子结构.因为此效应使用的是电荷流,更容易与现有的电子学技术兼容,它将推进新一代低能量消耗晶体管和电子学器件的发展.介绍了量子化反常霍尔效应的发展历程、产生机理,及其目前的研究进展.     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-