提升机单芯电缆磁场对电机编码器的干扰分析

介绍干熄焦提升机电机编码器在复杂的磁场中受到磁场的干扰后产生的异常数据对西门子S120变频器自动运行带来的影响,并分析了编码器数据出现异常的原因及解决方法。     

磁场处理对酿酒酵母微观结构及细胞膜流动性的影响及作用机理.

摘要：以磁场为外加物理场,采用恒定磁场及循环磁处理方式对酿酒酵母进行磁处理,研究酿酒酵母微观结构及细胞膜流动性的变化。通过透射电子显微镜,观察不同磁感应强度恒定磁场处理后酿酒酵母的微观结构,发现恒定磁场可以促进酵母细胞的生长,群体中以具有中央大液泡为特征的成熟细胞所占比率增大,同时线粒体呈现适应性膨大、增生。以原子力显微镜观察循环磁处理下酵母细胞的三维结构,发现细胞壁表面出现皱缩、穿孔,胞质外流,证实循环磁处理具有脉冲磁场的特征,可产生瞬间高能作用于细胞,从而产生致死效果。用荧光偏振法对两种处理方式下细胞的膜脂流动性进行测定,发现不同强度恒定磁场处理后,膜脂各向异性下降,流动性增强,0.05T磁感应强度下各向异性值下降3.57%,而循环磁处理后各向异性值比对照提高了8.46%,膜脂流动减慢,证实细胞膜为磁场作用的一个靶点。     

Magnetic response to atmospheric heavy metal pollution recorded by dust-loaded leaves in Shougang industrial area,western Beijing

Fifty-five evergreen tree＇s leaves growing less than one year were collected from Shougang industrial area in western suburb of Beijing, including steel plants and its ambient residential areas, recreational parks and farmlands. Rock magnetic properties and heavy metal contents were studied. The results show that the magnetic properties of leaf samples are predominated by Iow-coercivity magnetite, and both the concentration and grain size of magnetite particles gradually decreased with the distance from the main pollution source increases. Moreover, there is a significant linear relationship between magnetic parameters （the low-field magnetic susceptibility, saturation isothermal remanent magnetization and anhysteretic remanent magnetization） and heavy metals contents （Fe, Pb, V, Cr and Zn） （0.73≤ R≤ 0.88）. Hence, the magnetic parameters of leaves can serve as a proxy for quick detecting of the recent atmospheric metallic pollution.     

Convective high-speed flow and field-aligned high-speed flows explored by TC-1

From June 1, 2004 to October 31, 2006, a total 465 high-speed flow events are observed by the TC-1 satellite in the near-Earth region （-13 RE〈X〈-9 RE, ｜Y｜〈10 RE, ｜Z＋〈5 RE）, Based on the angle between the flow and the magnetic field, the high-speed flow events are further divided into two types, that is, field-aligned high-speed flow （FAHF） in the plasma sheet boundary and convective bursty bulk flow （BBF） in the center plasma sheet, Among the total 465 high-speed flow events, there are 371 FAHFs, and 94 BBFs, The CHF are mainly concentrated in the plasma sheet, the intersection angle between the flow and the magnetic field is larger, the magnetic field intensity is relatively weak, The FHF are mainly distributed near the boundary layer of the plasma sheet, the intersection angle between the flow and magnetic field is smaller, and the magnetic field intensity is relatively strong, The convective BBFs have an important effect on the substorm,     

对具有蜂窝点阵结构的S=2横向Ising模型基态磁性质的研究

对具有蜂窝点阵结构的S=2横向Ising模型,采用相关有效场理论,推导出系统的有限温度及基态纵向和横向磁矩公式,采用数值计算方法得到了基态的磁化曲线,重点考察了横场对系统基态磁性质的影响.研究表明,系统基态磁矩随晶场或横场的变化发生了三种相变:一级有序-有序相变,一级有序-无序相变,二级有序-无序相变.得到了横向磁场会减弱系统发生一级相变趋势的结论.     

一种精确的永磁同步电机数学模型及仿真模型的研究

通常在建立永磁同步电机的数学模型时,为了便于分析,都忽略了电机的铁耗.但在实际电机中铁耗总是存在的,并在电机的总损耗中占很大的比重.为此对永磁同步电机的铁耗数学模型和仿真模型进行了研究,建立了一种在d-q坐标系下永磁同步电机的铁耗数学模型.利用Matlab6.5/simulink5.0的强大功能,建立了永磁同步电机的仿真模型.为了验证仿真模型的正确性.采用转子磁场定向矢量控制进行了仿真验证,并对线性模型和铁耗模型进行了仿真比较.仿真结果证明,考虑铁耗的电机模型更能体现实际电机,用它来研究电机的动态性能更能反映电机的真实情况.     

论电场与磁场的相互转化

本文根据两个物理模型出发,论证了电场与磁场在不同参考系下的变换和统一性,表明电场和磁场本身是同一种物质的不同表现,电场力与磁场力是同一种力,它们在不同参考系下可以相互转化。     

强磁场下电磁振荡强度与频率对Zn-20% Bi过偏晶合金显微组织的影响

采用强磁场复合交变电流方法细化Zn-20%Bi过偏晶合金的显微凝固组织,研究了磁感应强度、电磁振荡强度和交变电流频率对Zn-20%Bi过偏晶合金显微组织的影响。随着磁感应强度的增加,合金组织中第二富Bi相粒径逐渐得到细化;随着电磁振荡强度的增加,富Bi相尺寸先减小后增加;随着交变电流频率的增加,富Bi相尺寸也是先减小后增加,存在一个最佳频率。并解释说明了各因素的影响机制。     

纳米材料锰掺杂量子点中的近藤效应

采用非平衡格林函数方法,探讨了量子点掺杂锰原子纳米材料的低温输运特性。结果表明,输运受到掺杂锰原子的强烈影响。具体来说,在微分电导中出现（2S＋1）个近藤劈裂峰,锰原子表现为一个多值量子化有效磁场,导致这种劈裂。     

汞原子塞曼效应分裂谱线的完整观测与分析

在简要回顾了汞光谱塞曼效应原理后,本文详细研究了运用法布里-帕罗干涉仪所得的汞光谱π分量谱线和σ分量谱线特征,包括如何由π线图像确定汞光源所处的磁感应强度,在σ分量谱线图像中K级前三条谱线的丢失及原因的理论分析,汞光谱诸塞曼谱线相对强度的测量及分析。