Determining Geomagnetic Field Induction Against a Background of Magnetic Interference from a Mobile Object

Determining the geomagnetic field induction is considered against a background of magnetic interference from a moving object, in which the angular position of the object is measured along with the projections of the magnetic induction vectors by means of three-component magnetometric sensors.     

Determination of the Geomagnetic Field Induction from a Mobile Ferromagnetic Object

The solution of the problem of determining the induction of the geomagnetic field from a mobile ferromagnetic object by measuring the angular position of the object and the projections of the magnetic-induction vectors using two three-component magnetometric sensors is considered.     

金属离子源磁过滤器磁场位形的设计与实验研究

根据磁过滤器对磁场的要求,利用水冷铜管产生的反向磁场,设计一个轴向磁场较弱的磁镜式磁过滤器.由数值模拟和实验研究的结果可知:磁过滤器磁场位形是一个轴向较弱的磁镜式磁场分布;并且在磁过滤器的出口处,磁场强度的均匀性较好;还增强了水冷铜管和磁过滤器壁之间的磁场.由离子束测试实验可知在加反向磁场时离子束的均匀性比没有反向磁场时高很多.     

多模式旋转磁场对电弧离子镀弧斑放电的影响分析

电弧离子镀工艺中,弧斑的放电形式、运动速率、运动方式的控制对于减少以至消除大颗粒的发射至关重要。本文采用自主研发的机械式旋转磁控弧源,围绕三种不同模式的旋转磁场下弧斑的放电行为及规律进行了研究,并从弧斑放电的物理机制出发,分析讨论了不同模式的旋转磁场对阴极斑点运动的影响机理。研究结果表明,多模式旋转磁场可以有效提高弧斑的运动速度、扩大放电面积、降低放电功率密度、减少大颗粒的发射,同时还能够大幅度提高靶材的利用率,拓展电弧离子镀的应用。     

Magnetic Field Stabilization for Magnetically Shielded Volumes by External Field Coils

For highly sensitive magnetic measurements, e.g., a measurement of the neutron electric dipole moment (EDM), the magnetic field has to be stable in time on a level below picoTesla. One of several measures we employ to achieve this uses an external field coil system which can stabilize the ambient external field at a predefined value. Here we report on the construction and characterization of such a system in the magnetic test facility at PSI. The system actively stabilizes the field along the axis of the EDM experiment by means of four coils in a Helmholtz-like configuration. Additional coils serve to compensate for transverse ambient field components. Because of the long integration times in the EDM experiment (about 100 s or more) only slow disturbances have to be corrected for. The performance of the system has been measured using static and moving magnetic sources and suppression factors in excess of 200 have been observed.     

Layered Superconductors in an External Magnetic Field

Presence of localized magnetic moments and inhomogeneites leads to an unconventional behavior of the upper critical field for layered superconductors. In addition, one can observe a large diamagnetic moment at H H _c2 and in the normal resistive state.     

Determining the angular position of a moving object

The angular position of a moving object may be determined from the measured vector for the acceleration due to gravity, the external magnetic field induction, and the magnetic induction from a source of alternating magnetic field. __________ Translated from Izmeritel’naya Tekhnika, No. 9, pp. 13–17, September, 2006.     

高精度智能磁场测量仪的设计

设计了一种由微处理器控制的具有通信接口的高精度智能磁场测量仪,通过双只配对的集成霍尔传感器来获取磁感应强度的信号,采用压频变换器完成数据的采集,并对仪器进行了校准和实验．实验结果表明,所设计的磁场测量仪在整个量程范围内的测量精度达到了0.1mT．该仪器不但可进行磁场的精密测量,还可用于对无线通讯基站电磁辐射的网络化远程监测．     

磁场在晶体生长中的应用

针对磁场在晶体生长中的应用,综述了近年来该领域数值模拟和实验研究的进展,包括静态磁场和动态磁场的产生原理及其在晶体生长中的效应。分析了晶体生长过程中存在的主要流动。综述了晶体生长过程中磁场力对导电熔体对流、固液界面形貌和杂质分布的影响,重点分析了磁场在直拉法单晶硅和定向凝固法多晶硅生长过程中的应用,总结了该领域当前存在的问题及其发展趋势。     

电磁场氮分压等对多弧离子镀TiN的影响

本文在不同工艺条件下，利用扫描电镜、Ｘ射线衍射仪，Ｍ－２００磨损机以及显微硬度计等，对多弧离子镀ＴｉＮ涂层的表面形貌组织结构以及性能进行了分析研究，揭示了电磁场氮分压对ＴｉＮ镀层的综合影响。     

高频磁场标准的研制

本文介绍采用标准磁场法和标准环天线法研制完成的国家高频磁场标准装置。其工作频率为１０ｋＨｚ～３０ＭＨｚ；发射场强为１～１００ｍＶ／ｍ；不确定度为０．２５ｄＢ。标准磁场法装置与标准环天线法装置的比对一致性为０．４５ｄＢ；标准环天线装置与ＴＥＭ室标准场装置的比对一致性为０．４０ｄＢ。     

强磁环境下的生物大分子结晶研究

近年来,随着超导磁体技术的进步,围绕与强磁场条件相关的应用得到迅速发展.对结构生物学领域的研究人员来说,强磁场有望成为一种可供选择的特殊环境,用于生物大分子结晶研究,并可能成为获取高质量生物大分子晶体的一种手段.就强磁场环境对生物大分子结晶过程的影响研究进行了评述,并对该领域的未来发展方向做了预期.     

Remote Field Eddy Current Control Using Rotating Magnetic Field Transducer: Application to Pressure Tubes Examination

The remote field eddy current (RFEC) technique is used to investigate the possibility of detecting the discontinuities practiced on pressure tubes samples from nuclear reactors, pressurized heavy water reactors (PHWR) type. In this article, we propose to develop the RFEC using the technique of rotating magnetic field (RMF). A method for calculating the field generated by the eddy current transducer with RMF using propagator matrix was developed. The experimental measurements are realized for artificial discontinuities practiced in pressure tubes samples.     

磁场诱导有序排列和自组装的研究进展

磁场是一种无接触的、新型的物理场,粒子受到这种物理场的作用会发生取向形成有序结构,从而赋予材料新颖的光、电、磁等特性.综述了在磁场作用下粒子有序排列和自组装的研究进展.     

磁场作用下的金属凝固研究进展

磁场作用下的金属凝固已成为金属材料基础研究和开发制备新技术的重要领域.综述了交变/旋转磁场、直流磁场作用下金属凝固的研究历史及现状,运用电磁学及金属凝固原理,揭示了磁场对凝固组织形貌及凝固过程产生的影响及主要机制,并对以后的理论研究工作提出了建议.     

磁场作用对等规聚丙烯结晶行为的影响

通过偏光显微镜(POM)、广角X射线衍射(WAXD)、差示扫描量热仪(DSC)等手段研究了磁场作用对熔融聚丙烯的结晶形态及其与热历史的关系。结果表明,在磁场作用下,聚丙烯球晶尺寸变大,能观察到球晶内部的叶脉状晶体单元;随着熔融温度升高和熔融时间的延长,磁场作用的效果更加明显。磁场作用不利于β晶的生长,会使聚丙烯的结晶更加完善;在磁场作用下熔融、结晶的聚丙烯,结晶度无明显的改变,而于磁场外熔融的聚丙烯在磁场作用下等温结晶时,结晶度有明显的提高。     

行波磁场在晶体生长过程中的研究进展

针对行波磁场的应用评述了其近几年理论和实验的研究进展,包括行波磁场原理、行波磁场发生器的设计、行波磁场在晶体生长过程中的效应。论述了在晶体生长过程中行波磁场引起的子午线流对导电熔体的稳定性、生长界面形貌和溶质分布的影响,指出了该领域当前研究存在的问题并展望了其发展趋势。     

Magnetic Field Design by Using Image Effect from Iron Shield

Permanent magnet rings are presented, which exploit the image effect in the surrounding circular iron shields. The theory is given for a general permanent ring when the magnetization orientation at each coordinate angle ψ changes by =(n+1)ψ, where n is a positive or negative integer. For the uniformly magnetized case n=-1, the permanent ring produces no field in its bore, and the field is that of a dipole outside. When the ring is surrounded by a soft iron shield, its field becomes uniform in the bore, and zero outside the ring. The field can be varied continuously by moving the iron shield along the magnet axis. A small variable field device was constructed by using NdFeB permanent rings, which produced a field flux density of 0-0.5 T in the central region.     

磁粉退磁场和退磁因子的理论计算

根据建立的物理模型和数学模型，对单个球形磁粉在漏磁场中的退磁场和退磁因子作了详细的理论计算，从而为磁粉的受力分析等研究提供了一定的理论基础。