无损残余应力测量及其新技术

简述及比较了主要的残余应力无损测量技术，重点为磁力法，并介绍一台新的磁力仪MAPS，且对MAPS及传统磁力仪作了比较，同时以X射线及中子衍射得到的结果验证了MAPS的可靠性，也介绍了文献上较少见的火车钢轨残余应力分布图。     

Experimental and theoretical study of the nonlinear response of agiant magnetostrictive rod

In this paper, a magnetomechanical coupling constitutive relation of the giant magnetostrictive material was investigated experimentally and theoretically. A grain-oriented magnetostrictive rod of iron and rare earth was tested under a combined magnetomechanical loading. Two types of experimental curves were obtained, i.e., the magnetostrictive curve of the extensional strain vs the magnetic field, and the curve of the magnetic polarization intensity vs the pre-stress. A new theoretical constitutive model, based on the density of domain switching, is developed. Comparison of the theoretical predictions with the experimental results indicates that this model can capture the main characteristics of the magnetoelastic coupling deformation of a giant magnetostrictive rod. The project supported by the National Natural Science Foundation of China (10025209, 10132010, 10102007)     

Magnetic filtration with magnetized granular beds： Basic principles and filter performance

This study is devoted to the explanation of different characteristics of magnetic filtration and the way these characteristics affect the important filtration parameters. Magnetic fields in pores and the force effect of these fields on magnetic particles and the magnetization properties of packed beds composed of ferromagnetic spheres and metal chips are evaluated. The profile of accumulation and capture regions of the particles, the variation of the fluid velocity in these regions and analytic expressions of particle capture radius are presented. The effects of filtration regime parameters on magnetic filter performance were investigated. An analytical expression has been obtained for the dependence of the logarithmic efficiency coefficient on filtration velocity, the geometry of filter elements, the particle size and other parameters of filtration. The stationary and non-stationary equations of the magnetic filtration processes are given. An expression of magnetic filter performance is shown with dimensionless parameters obtained from the filtration system. These relations are useful for calculations in engineering practice, including the design of magnetic filters, provision of suggestions on construction, and optimization and control of filter operation.     

Magnetically stabilized bed reactor for selective hydrogenation of olefins in reformate with amorphous nickel alloy catalyst

A magnetically stabilized bed （MSB） reactor for selective hydrogenation of olefins in reformate was developed by combining the advantages of MSB and amorphous nickel alloy catalyst. The effects of operating conditions, such as temperature, pressure, liquid space velocity, hydrogen-to-oil ratio, and magnetic field intensity on the reaction were studied. A mathematical model of MSB reactor for hydrogenation of olefins in reformate was established. A reforming flow scheme with a post-hydrogenation MSB reactor was proposed. Finally, MSB hydrogenation was compared with clay treatment and conventional post-hydrogenation.     

虚构的法拉第定律与几个关键实验不符

由于法拉第定律是虚构,所以它不具有普适性,感应电流的产生与磁通量变化率无关,产生感应电流的物理本质是完整洛伦兹磁力。     

基于动态磁耦合的驰振能量收集器动力学分析

为了提高能量收集系统在低风速下的能量收集效率,将动态磁铁非线性引入到驰振能量收集系统中。在悬臂梁的末端和底座上分别安装一对磁极相斥的磁铁,其中安装在底座上的磁铁与弹簧相连,可随着磁斥力的变化而垂直移动。首先,根据能量法建立了磁耦合驰振能量收集系统的多场耦合振动控制方程。其次,通过Runge-Kutta数值计算方法比较分析了低风速下动态磁耦合驰振能量收集系统(DM-GEH)和固定磁耦合驰振能量收集系统(FM-GEH)的电压输出。DM-GEH系统的切入风速提前了81.82%,在1 m/s～5 m/s风速范围内能量收集效率提高了124.22%。最后,针对弹簧支撑刚度进行参数优化,提升了低风速下的能量收集效率。结果表明,通过改变磁铁支撑方式至弹性支撑将改变系统的振动频率并且降低切入风速,相较于弹簧刚度为1 000 N/m时,弹簧刚度为500 N/m时的系统的切入风速降低了54.55%,能量收集效率提高了15.35%。     

广义洛伦兹磁力的定义及证明

给出了广义洛伦兹磁力的定义和证明,论证指出电场既不是动磁场直接产生的更不是变磁场产生的;先有感应电流I,后有电压Uab和电场Eab。解决了愣茨与法拉第之间的原因与结果的哲学争议问题;在当时没有发现电子的情况下,法拉第的漩涡电场及其电动势都是虚构的;完整洛伦兹磁力是电磁感应的物理本质。     

磁性量子元胞自动机功能阵列的实验研究

采用电子束光刻、热蒸镀和剥离工艺在室温下制备了多组磁性量子元胞自动机器件功能阵列. 实验研究了曝光剂量和曝光时间对三个不同间距参数磁性量子元胞自动机阵列图案的影响, 发现100 pA电子束束流和0.38 μs曝光时间可获得理想的阵列图案. 对制备的反相器阵列结构进行了磁力显微测试, 结果显示了正确的逻辑功能, 成功实现了不同间距参数功能阵列的实验制备. 此外, 实验还发现纳磁体阵列制备中容易出现缺陷, 模拟结果表明丢失纳磁体缺陷导致了信号传递反相.     

水浴磁力搅拌碱消解-火焰原子吸收分光光度法测定土壤中铬（Ⅵ）

建立水浴磁力搅拌碱消解火焰原子吸收分光光度法测定土壤中铬（Ⅵ）。称取5.00 g土壤样品置于250mL聚乙烯瓶中，以20 g/L氢氧化钠和30 g/L碳酸钠碱性提取液提取，提取温度为93℃，提取时间为75 min；加入400mg氯化镁，调节滤液p H值为7.0～8.0。铬（Ⅵ）质量浓度在0.0～2.0 mg/L范围内线性相关系数为0.999 5，检出限为0.4 mg/kg。该方法应用于低、中、高3种铬（Ⅵ）土壤国家标准物质的分析，测定值与认定值相符，测定值的相对标准偏差为5.0%～7.7%(n=12)。