Corrosion behavior of T2 copper in 3.5% sodium chloride solution treated by rotating electromagnetic field

Copper is susceptible to producing corrosion problems in corrosive environments, which leads to serious safety problems. Thus, investigating the corrosion behavior of copper is of great significance. The effects of rotating electromagnetic field on corrosion behavior of T2 copper in 3.5% sodium chloride solution with electrochemical measurements were investigated. The results showed that rotating electromagnetic field changed properties of 3.5% sodium chloride solution by increasing the values of temperature and pH and decreasing the values of conductivity and dissolved oxygen. The rotating electromagnetic field improved the corrosion resistance of T2 copper. The corrosion products of T2 copper in treated 3.5% sodium chloride solution were composed of Cu20 and CuCl. The low corrosion rate of T2 copper was resulted from the decrease of dissolved oxygen in 3.5% sodium chloride solution treated by rotating electromagnetic field.

Crystal orientation and corrosion resistance of CuNi10Fe1Mn alloy billet under rotating electromagnetic field

CuNi10Fe1Mn alloy billet under rotating electromagnetic field (REF) was characterized in this work. The change of the crystal orientation was first explored by X-ray diffraction (XRD) and scanning election microscope (SEM); the corrosion resistance was done by three electrodes system, and the natural sea water was used as corrosion medium. The results demonstrate that the strongest crystal orientation is transformed from crystal plane (200) to (111); moreover, the crystal plane (111) whose intensity is the strongest on the cross section and vertical section with REF causes the tubes be rolled easily, and the corrosion resistance of the billet is increasing with REF. As a result, properties of CuNi10Fe1Mn alloy tubes can be improved by REF.

Electromagnetic Field Created by Rotation of Celestial Bodies

The observed correlation of the angular momenta Lik and magnetic moments μlm of celestial bodies (the Sun, planets and stars) was discussed by many authors but without any explanation. In this paper, a possible explanation of this phenomenon is suggested. It is shown that the function satisfies Maxwell equations and can be considered as a function which determines the electro-magnetic properties of rotating heavy bodies. The Riklm is the Riemann tensor, which determines the gravitational field of the body, rg is the gravitational radius of the body, and η is the constant which has to be determined by observations. The field Φlm describes the observed correlation. It explains the stability of magnetic field of white dwarfs and neutron stars despite the ohmic dissipation. The function Φl0 describes the electric field created by rotating heavy bodies. The presented theory does not contradict any existed experiments and observations.

Research on hydrokinetics characteristics of rotating pipe fluid in the crossed electric and magnetic field

The rotating pipe fluid in the crossed electric and magnetic field not only suffered the forces in the steady condition, but also suffered Coriolis force, centrifugal force because of rotation and electromagnetic volume force. The motion equation of fluid and the hydrokinetics equations of rotating pipe were described in the Cartesians coordinates. The equations showed that the solutions to hydrokinetics equations of rotating pipe in the crossed electric and magnetic electromagnetic field were highly complicated and numerical calculations were also astronomical. The pressure distribution and temperature distribution of one dimension were solved using the electromagnetic equations set. The results showed that the fluid in rotating pipe was in the asymmetrical pressure field and temperature field because it was in the energy exchange and thermo-electrical coupling course. The primary characteristic of flow course could be expressed using the proposed hydrokinetics equations.

A Novel Explanation of the Origin of the Magnetic Field of Stars and Planets

Today, the origin of the magnetic field of stars and planets is explained by the dynamo effect. Since Cowling’s anti-dynamo theorem has forbidden a purely axisymmetric dynamo, scientists are all convinced today that the fluid flow in the core of a star cannot be laminar, so it is turbulent. However, we will see in this study that the configuration in which the conductive fluid contained in the core of a star is in rapid rotation around an axis of symmetry is the one that best explains the origin of the magnetic field of stars and planets. It also explains why certain types of stars have very intense magnetic fields. Indeed, we will show here that the magnetic field of stars and planets is created by the electric current generated by the rotational movement of charged fluid particles as in an electromagnet. The lines of this magnetic field are channelled by the solid paramagnetic seed which plays the role of magnetic core in the cores of planets and stars. The seed is composed mainly of Iron and Nickel on the planets and of solid helium-3 in the stars. In this work, we will use this model of rapidly rotating fluids to introduce a new way to ionize a neutral gas and maintain it in a plasma state for indefinitely large time scales, to present a new technique for generating very intense magnetic fields, to establish a new magnetic nucleation process and to propose a new type of nuclear fusion reactor in which the plasma is perpetually rapidly rotating.

Flow Structure in RH Vacuum Degasser Using Rotating Electromagnetic Field

An innovative steelmaking process is suggested using an electromagnetic driven swirling flow in the up-leg of an RH vacuum degasser.A physical and a mathematical model based on 300t RH vacuum degasser are developed to understand the effect of rotating electromagnetic field on the circulation flow rate and the two phases flow behavior of RH system.Both water model experiments and numerical simulation show the flow pattern and distribution of gas bubbles. The gas bubbles move towards the centre of up-leg under the effect of rotating electromagnetic field,and the accumulation of gas bubbles depends on the magnetic intensity.An optimization value of magnetic intensity was suggested in this paper.

Flow fields control for bubble refinement induced by electromagnetic fields

Large bubbles seriously reduce the efficiencies of the interactions between the bubbles and the molten steel,such as energy transfer,momentum transfer,mass transfer and chemical reaction.To reduce the size of the bubbles and increase the gas–liquid interface area,a novel non-intrusive method of bubble refinement was proposed,which only depends on the molten steel flow field controlled by the rotating electromagnetic field.The flow fields of the molten steel for bubble refinement were analyzed,and the corresponding bubble refinement was investigated.It was found that the molten steel formed obvious rotating turbulent flow for bubble refinement under the unidirectional rotating electromagnetic field.However,the large vortex in the center of the molten pool caused by the rotating flow made the bubbles aggregate and coalesce again,resulting in formation of larger bubbles and gas cavity.To suppress the central vortex formation and enhance the bubble refinement,the forward-reverse rotating electromagnetic field for bubble refinement was proposed.The irregular and chaotic flow occurred repeatedly because of alternating forward and reverse rotating in a short period,so that the turbulent kinetic energy and turbulent dissipation of the flow field always remained at a high level which favors bubble refinement.As a result,the bubble diameter can decrease by more than 50%compared to that without electromagnetic field.Furthermore,it is important that this non-intrusive kind of bubble refinement method completely avoids the introduction of non-metallic inclusions caused by intrusive configuration.

多极矩重接式电磁发射器直线与旋转同步加速研究

为研究抛体电枢旋转在保持飞行稳定性、保证射程和射击精度中的作用,提出了一种基于开槽电枢的多极矩重接式电磁发射模式。首先,通过构建不对称感应涡流场,为开槽电枢提供了轴向电磁力和轴向电磁力矩,实现了开槽电枢直线与旋转同步加速运动;然后,对径向瞬态磁场与不对称感应涡流场的相互作用原理进行了理论分析,并对开槽电枢的直线与旋转加速性能进行了动态仿真,得到了开槽电枢的最佳触发位置和最佳扭转角。有限元仿真结果表明:在电容值为800μF、初始电压为10 kV的脉冲电容器驱动下,重量为1 kg的开槽电枢可以加速到84.7 m/s和7080 r/min,发射效率达到11.7%,最佳触发位置和最佳扭转角分别为8 mm和3°。

用于电磁波吸收的碳纳米管水泥基复合材料

采用弓形法对多壁碳纳米管(MWCNTs)水泥基复合材料的吸波性能进行了实验研究。结果表明,当MWCNTs掺量为0.6%(质量分数)时,厚度为25mm的试样在2.9GHz处获得最强吸收峰值-28dB,并能够在2～8GHz范围内对出现在吸收峰值附近的电磁波进行充分吸收;厚度为35mm的试样在8～18GHz表现出良好的宽频吸波性能。当MWCNTs掺量为0.9%(质量分数)时,水泥基复合材料在8～18GHz低于-10dB的带宽达到7.1GHz。力学强度测试结果表明MWCNTs在一定掺量范围内改善了水泥基材料的力学强度,但掺量的继续增大会导致力学强度的下降。MWCNTs掺量为0.9%(质量分数)的水泥砂浆抗压强度为60.2MPa,抗折强度为10.2MPa,虽然较空白试样有所下降,但仍有较高的力学强度。

旋转电磁场作用下金属凝固补缩机理探讨

研究了金属熔体在旋转电磁场作用下的凝固过程。据金属凝固理论和磁流体力学分析 ,电磁搅拌力引起的动量对流对补缩的促进作用并不大。旋转电磁场阻碍中心疏松、缩孔形成的机制为 :电磁力引起的动量对流增强了熔体的热、质传输过程 ,使熔体温度分布更趋均匀 ,温度梯度减小 ,使心部熔体的固相率更趋一致且在短时内增至特征固相分数 ,且凝固末期熔体的凝固速率增大 ,使心部熔体在短时内凝固 ,从而避免了中心疏松。

新型旋转电磁热机三维电磁场方程的求解及相关电磁参数的研究

建立了旋转电磁热机的三维简化模型,在此基础上给出了三维电磁场方程。结合实际的磁通分布,给定方程的边界条件,并利用分离变量法求出其解析解。利用电磁场方程的解析解,推导出电磁热机端部系数的计算公式。利用基于二维有限元法的电磁热机热功率算法,实际计算了一台样机的热功率,并对其进行了测试。计算和测试结果表明,经过端部系数修正后的热功率计算值与测试值接近。对方程的解析解进一步分析得到电磁热机结构参数与热功率之间的解析表达式,利用其计算得到极对数、气隙长度、定子内径和铁心长度与热功率的关系曲线,并进行了相关分析。

旋转磁场对ZA-27合金组织的影响

采用电磁搅拌法，研究在旋转磁场作用下对ＺＡ－２７合金组织的影响，并对流变组织的形成机理作了初步的探讨。还研究了改变工艺条件（如交替改变磁场旋转方向和加入微量合金元素）对流变组织的影响。

基于旋转电磁效应的海水淡化器原理结构和压强场的分析

基于旋转电磁效应,提出了旋转电磁离心式海水淡化器,该淡化器综合利用了旋转电磁效应和旋转离心力,即利用磁和热处理海水,高速旋转产生的离心力趋使海水通过物理膜,实现抑垢、缓蚀、延长膜使用寿命和降低能耗的目的。介绍了原理结构和工作机理,通过理论推导和数值模拟重点研究了淡化器的压强场,给出了压强分布特性,并把理论计算值和数值模拟值进行了对比。研究表明旋转电磁离心式海水淡化器的可行性,其完全充分地利用了电磁能、热能和机械能,还表明淡化器中存在压强场,并能为海水通过物理膜提供所需的压强,实现了能量的合理利用,表现出良好的节能效果,具有广阔的应用前景。

低频电磁场下原位合成Al-Zr-O系复合材料机制研究

为研究低频电磁场下铝基原位复合材料的合成机制，以A356-Zr（CO3）2反应组元制备出Al-Z-O系复合材料，在低频旋转电磁场条件下原位合成了微米级颗粒增强铝基复合材料。研究表明：当感应线圈内输入电流150A，频率4Hz时，对应磁场强度为0.25T，X射线衍射结果显示基体中增强相为Al3Zr和Al2O3；SEM观察该条件下合成的复合材料凝固组织发现，生成的增强颗粒细小，粒径1-2μm，而且在基体中均匀弥散分布。对原位反应的热力学和动力学过程分析表明：反应的关键环节是高温铝液和ZrO2固液相间反应，电磁场力作用加大了反应体系的混合对流运动，提高了传热传质和物质扩散速度，并促进了颗粒在基体中的弥散分布。

旋转磁场用于原铝净化的研究

根据电磁流体力学的基本理论,研究了在旋转磁场作用下原铝熔体的净化过程·分析了体系的电磁力和重力的影响因素,研究了铝熔体中杂质铁和硅的物理性能·分析表明,原铝中杂质铁以Al3Fe的形式存在,而杂质硅以单质形式存在·在分析了重力、电磁力和离心力的综合作用后,利用电磁力与偏析的共同作用实现了原铝中杂质铁和硅的分离·考查了主要影响因素,即磁场强度、凝固时间、气隙大小和坩埚位置等·研究结果表明,旋转磁场作用下的原铝熔体偏析净化的方法综合了电磁力、重力和偏析的共同作用,它可以使原铝中Fe和Si的质量分数由0 16%降至0 05%·

旋转电磁场对BFe10-1-1合金管坯组织及力学性能的影响

研究旋转电磁场对水平连铸空心BFe10-1-1合金管坯凝固组织和力学性能的影响,并对其机理进行初步的探讨。结果表明:在工频旋转电磁场的搅拌作用下,BFe10-1-1合金管坯的凝固组织显著细化,由粗大的柱状晶完全转化为均匀细小的等轴晶,同时抑制了Ni元素的枝晶偏析;施加电磁场后管坯的力学性能得到明显改善,当励磁电流为80 A时,管坯抗拉强度提高了15.3%,屈服强度提高了10.9%,伸长率提高了58.6%。

三芯电力电缆各芯线电流测量偏心误差的计算和补偿方法

用磁传感器测量三芯电力电缆各芯线的电流时,磁传感器阵列的中心可能偏离电缆中心,致使测量结果中含有由此产生的误差即偏心误差,为此提出一种对偏心误差的计算和补偿方法。在原有测量方法基础上,将磁传感器阵列沿电缆轴向安装表面旋转180°,测量新位置上的磁感应强度。通过求解非线性方程组,可以确定偏心误差的大小;并据此对测量结果进行补偿,可得到计及偏心误差情况下三芯电力电缆各芯线电流值的实际大小。电磁场有限元仿真试验结果表明,所建立的解析模型具有很好的准确性,验证所提出计算和补偿方法的有效性。

磁场模拟在磁控溅射/阴极弧离子镀中的应用

针对磁控溅射和阴极弧离子镀沉积技术存在的局限性,采用有限元分析方法(Finite element method,FEM)进行磁场模拟,优化设计外加电磁线圈的结构和磁场分布位形,并应用于磁控溅射沉积透明导电氧化物和阴极弧离子镀沉积硬质薄膜中。分析了外加电磁线圈磁场对磁控溅射等离子体辉光变化、磁控靶磁场平衡度/非平衡度、以及线圈位置对等离子体特性和靶材利用率的影响。设计和制作了轴对称磁场和旋转磁场,研究了它们对阴极弧离子镀弧斑运动形貌和薄膜表面大颗粒等特性的影响。通过控制弧斑运动状态,可以得到不同程度的颗粒分布,实现颗粒的可控沉积,减少薄膜表面大颗粒的污染。

内核地球的自转运动和地球固定参考系的研究

本文研究了内核地球模型下的地球表面的旋转运动和地球形变场的复数矢量球函数表示,以及外壳固定参考架、地球参考系的理论定义和它们之间等价性的理论证明.同时给出了液体外核(FOC)、固体内核(SIC)和整体地球的转动惯量张量和角动量的具体表达式.在考虑到引潮力位对地球形变场的影响下,研究了地幔相对角动量的具体表述.本文的工作是对前人有关理论的扩展和改进,对进一步研究内核地球自转的动力学理论是非常重要的.

电扫描实现旋转磁场跟踪仿真研究

在电磁跟踪系统中,磁场源的优化设计不仅可简化系统结构,还可提高系统性能。设计了一种电控旋转磁场源,并对该磁场源实现电磁跟踪的可行性进行了仿真研究。首先提出了一种立方体磁芯缠绕三轴正交方形线圈,通过控制3个正交线圈激励电流强度,实现合成磁感应强度矢量旋转的磁场源方案;之后,采用有限元分析法,通过仿真软件ANSYS对其空间磁场分布情况及激励电流对磁场分布的影响进行了仿真研究。仿真结果表明:可以通过控制三轴线圈的电流强度,控制立方体三轴正交线圈合成的总磁感应强度最大值的方向,实现磁场的"旋转"。该磁场源方案符合电扫描实现旋转磁场跟踪的要求,为下一步的实际系统设计提供了依据。