Weak Delocalization in Graphene on a Ferromagnetic Insulating Film

Graphene has been predicted to develop a magnetic moment by proximity effect when placed on a ferromagnetic film, a promise that could open exciting possibilities in the fields of spintronics and magnetic data recording. In this work, the interplay between the magnetoresistance of graphene and the magnetization of an underlying ferromagnetic insulating film is studied in detail. A clear correlation between both magnitudes is observed but through a careful modeling of the magnetization and the weak localization measurements, that such correspondence can be explained by the effects of the magnetic stray fields arising from the ferromagnetic insulator is found. The results emphasize the complexity arising at the interface between magnetic and 2D materials.     

High-pressure dc sputtering of High-Tc BPSCCO thin films withTc(0) above 100 K

High-T _c Bi(Pb)-Sr-Ca-Cu-O thin films have been made on single-crystal MgO substrates using high-pressure dc sputtering technique. X-ray studies confirm the crystallinity and highly oriented structure withc-axis perpendicular to the substrate. By optimizing the annealing schedule the formation of the high-T _c phase is stabilized. The best film exhibited superconducting transition temperature with zero-resistance temperature,T _c(0), as high as 101 K. Temperature dependence ofJ _c indicates the presence of Josephson-type weak links.     

弱凝胶调驱降维数值模拟方法研究

目前用于弱凝胶调驱的化学驱软件大多存在计算速度慢、数值弥散现象严重的问题,为了提高弱凝胶调驱数值模拟的速度和精度,提出了降低维数的模拟方法。利用追踪流线的方法,将弱凝胶调驱的三维渗流问题,转化为沿流线计算饱和度的一维问题,大大降低了求解饱和度方程组中方程的数目,从而提高了计算速度。利用该方法,模拟了玉门老君庙油田一个试验井区的水驱开发历史,优化了弱凝胶调驱的注入浓度、注入速度及注入体积等参数,并预测了弱凝胶调驱的动态,预测该方案可提高采收率7.6%。     

Congruences and ideals in pseudoeffect algebras

This paper is devoted to congruences and ideals in pseudoeffect algebras. Let I be a normal ideal in a pseudoeffect algebra E. We show that: (1) the relation ~ _I induced by I is a congruence if and only if for every a∈E, I∩ [0,a] is upper directed; (2) the relation ~ _I induced by I is a strong congruence if and only if I is a normal weak Riesz ideal in a pseudoeffect algebra E. Moreover, we introduce a stronger concept of congruence—namely Riesz strong congruence—and we prove that, if I is a normal weak Riesz ideal in a pseudoeffect algebra E, then ~ _I is a Riesz strong congruence and, conversely, if ~ is a Riesz strong congruence, then I = [0]_~ is a normal weak Riesz ideal, and ~ _I = ~. This work was supported by the National Natural Science Foundation of China (Grant No. 10271069).     

A Survey on the Numerics and Computations for the Landau-Lifshitz Equation of Micromagnetism

The Landau-Lifshitz (LL)equation of micromagnetism governs rich variety of the evolution of magnetization patterns in ferromagnetic media. This is due to the complexity of physical quantities appearing in the LL equation. This complexity causes also an interesting mathematical properties of the LL equation: nonlocal character for some quantities,nonconvex side-constraints, strongly nonlinear terms. These effects influence also the numerical approximations. In this work, recent developments on the approximation of weak solutions, together with the overview of well-known methods for strong solutions,are addressed. Author is supported by the Fund for Scientific Research - Flanders FWO (Belgium).     

弱电工程施工和管理研究与探讨

弱电工程项目的质量控制的关键是对工程的设计、施工和管理过程进行严格的控制和把关,并按规范步骤进行操作和实施。通过工程的前期沟通、技术选择、需求确定、配置清单和施工图纸等措施可规范设计过程。通过施工前会议、施工要点、材料和设备采购、工程进度、方案设计等措施可规范施工过程。通过制定施工组织和协调管理等措施可规范施工管理。通过规范的设计、施工和管理可以提高工程质量和工程效益。     

智能建筑弱电技术的研究

通过对智能建筑弱电技术中的电线/电缆导管的敷设、电气照明安装、工程中的冲突以及弱电系统的施工计划等问题的研究,总结了智能建筑弱电技术中的综合布线系统、计算机网络系统、子系统间接口方面、母线的安装、弱电设备功能以及配电装置等技术问题的解决要点。所述内容对智能建筑整体运行和安全管理以及电气施工安装的质量监控等具有较强的参考价值。     

高灵敏度弱磁传感器研究

磁传感器在生物医学、资源探测和航空航天等领域有巨大的应用价值,基于原子自旋的弱磁传感器拥有目前最高的磁场测量灵敏度。但通常的方案采用射频场调制或远离共振的激光检测,前者增加了磁力仪的线宽,而后者对激光频率的锁定带来了困难。为了解决以上问题,提出了一种基于激光强度调制和圆二向色性检测的原子弱磁传感器方案,详细描述了其工作原理和系统构成,并对原子弱磁传感器的性能进行了测试。实验结果表明:原子弱磁传感器的磁共振线宽为22 Hz,在对恒定磁场进行30 min连续测量时,峰峰值抖动小于9 pT,灵敏度达到了0.12 pT/Hz1/2。     

用Alltech DS-Plus~(TM)离子色谱抑制器测定有机弱酸

葡萄糖酸、乙酸、甲酸、丙酮酸、山梨酸等有机弱酸在流速为 1 m L/ min,淋洗液的浓度为 1mmol/ L Na HCO3 ,用 Alltech DS- Plus TM抑制器时能很好地检测。弱电离物质检测限分别为 0 .5 0 0μg/ m L、0 .1 45 μg/ m L、0 .0 97μg/ m L、0 .1 95 μg/ m L、1 .0 78μg/ m L(S/ N=3 ) ,具有良好的线性关系和重现性。对饮料样品进行测定 ,结果令人满意。