基于功能梯度磁电复合材料的新型自偏置磁传感器

文章采用超磁致伸缩材料Terfenol-D(Tb0.37Dy0.63Fe2)、金属玻璃Metglas 2605SA1和压电材料PZT(Pb(Zr, Ti)O3)，设计了一种基于功能梯度磁电复合材料的新型自偏置磁传感器.利用Metglas和Terfenol-D之间的磁导率和矫顽力差异产生较强的磁化梯度，打破原有的平衡状态，导致内建磁场产生，进一步提高了零偏置磁场下磁致伸缩材料的压磁系数和磁电响应.实验结果表明：该传感器获得了较高的低频和高频零偏置磁电电压系数，分别达到9.14 mV/Oe和572 mV/Oe，并且谐振磁电电压输出和激励交变磁场之间呈线性变化关系.该自偏置磁传感器避免了传统磁电传感器对偏置磁场的依赖，具有制作简单、成本低、体积小，无需偏置磁场以及灵敏度高等优点.     

纯电动汽车磁助力启动制动结构设计

根据纯电动汽车整丰在运行条件下制动力矩的需求，设计了一种磁助力启动制动系统。利用电磁同性相斥、异性相吸的原理，根据车轮速度时时变化控制和改变磁极磁性，在汽车起步和制动过程起到磁助力作用。计算了电磁启动制动力矩，设计了电磁制动控制电路。基于ECE法规设计了制动力分配算法，计算表明：在高响应测速传感器的反馈控刺中，磁动力启动制动结构能够迅速有效地起到助力作用，为改善纯电动汽车的行车效能提供了新的思路。     

作业成本法下的成本动因选择研究

Homburg教授提出了作业成本法下成本动因的最优化选择模型,但是并没有对该模型要依赖的成本动因集合进行相关性分析,不能保证所选择成本动因的相关性和独立性.本文在Homburg教授的模型基础上,运用偏相关性分析和假设检验,保证了所选择成本动因的相关性和独立性,从而避免了Homburg教授的模型可能得出的不合理结果.     

均匀磁场中的平面载流线圈

本文以最普遍的方式讨论了任意形状的平面载流圈在均匀磁场中的力学性质，从而在普遍的意义上定义了平面载流圈的磁矩．     

Functional and dynamic magnetic resonance imaging using vector adaptive weights smoothing

We consider the problem of statistical inference for functional and dynamic magnetic resonance imaging (MRI). A new approach is proposed which extends the adaptive weights smoothing procedure of Polzehl and Spokoiny that was originally designed for image denoising. We demonstrate how the adaptive weights smoothing method can be applied to time series of images, which typically occur in functional and dynamic MRI. It is shown how signal detection in functional MRI and the analysis of dynamic MRI can benefit from spatially adaptive smoothing. The performance of the procedure is illustrated by using real and simulated data.     

Health‐Economics Analyses Applied to ELF Electric and Magnetic Fields

Extremely low frequency electric and magnetic fields (ELF EMFs) are a common exposure for modern populations. The prevailing public‐health protection paradigm is that quantitative exposure limits are based on the established acute effects, whereas the possible chronic effects are considered too uncertain for quantitative limits, but might justify precautionary measures. The choice of precautionary measures can be informed by a health‐economics analysis (HEA). We consider four such analyses of precautionary measures that have been conducted at a national or state level in California, the Netherlands, the United Kingdom, and Israel. We describe the context of each analysis, examine how they deal with some of the more significant issues that arise, and present a comparison of the input parameters and assumptions used. The four HEAs are methodologically similar. The most significant qualitative choices that have to be made are what dose‐response relationship to assume, what allowance if any to make for uncertainty, and, for a CBA only, what diseases to consider, and all four analyses made similar choices. These analyses suggest that, on the assumptions made, there are some low‐cost measures, such as rephasing, that can be applied to transmission in some circumstances and that can be justifiable in cost‐benefit terms, but that higher cost measures, such as undergrounding, become unjustifiable. Of the four HEAs, those in the United Kingdom and Israel were influential in determining the country's EMF policy. In California and Netherlands, the HEA may well have informed the debate, but the policy chosen did not stem directly from the HEA.     

同轴方形载流线圈间的磁力(英文)

为获得二同轴方形载流线圈间相互作用磁力，计算出了线圈间的互感系数。将虚功原理作为一种简捷方法加以运用，对该力极值位置进行了分析和图示。讨论平面内二同心方形线圈载流时一线圈不受磁张力的优良力学状态。     

装备制造业技术创新的文化驱动

装备制造业的技术创新能力对国民经济和社会发展有着重要影响。基于技术的社会形成理论,提出装备制造业相关社会群体对技术商品有效性达成相同的理解,既是技术创新得以实现的基础,更能产生持续开展技术创新的强大文化驱动力量。据此,对我国装备制造业技术创新的内源性文化驱动、外源性文化驱动和关联性文化驱动进行系统解读。     

The Efficacy of Different Methods for Informing the Public About the Range Dependency of Magnetic Fields from High Voltage Power Lines

The AC electric and magnetic fields associated with high voltage power lines have become a concern as a possible health risk. In most cases the strength of these fields decreases as the inverse square of the distance from the line. In earlier work, we found that laypeople do not understand how rapidly field strength decreases with distance. Most believe that any high voltage power line they can see is exposing them to strong fields. This paper confirms the earlier finding and explores a number of strategies which might be used in risk communications to correct this misperception. We found it relatively easy to provide subjects with a better understanding of the range-dependency of magnetic field strength. Moreover, the quality of this acquisition was apparently independent of the manner in which they were instructed. Such successful instruction is markedly different from the well-established difficulty of teaching people about many qualitative domains, such as physics or ideas in probability. Clearly, while some erroneous beliefs are highly resistant to change, others can be altered quite readily. We suspect that an important distinction between knowledge about the range-dependency of power-frequency magnetic fields and less tractable topics involves the presence or absence of prior folk-theories or "mental models" of the domain.     

The digital rainbow: Some history and applications of numerical spectrum analysis

Statistical concepts and techniques are basic to scientific investigation. One concept that enjoys both a theoretical and a physical existence is the spectrum. A spectrum may be described as a display of the intensity or variability of a phenomenon versus period or frequency. Spectra are particularly useful in the study of systems subject to resonance, but have many other uses. This paper begins with some of the historical development of the field, describing a sequence of contributions by Michelson, Schuster, Einstein, Fisher, Bartlett, Tukey, and Whittle. The paper next presents collaborative applications to the study of the free oscillations of the earth, to the dispersion of seismic surface waves and to nuclear-magnetic-resonance spectroscopy. Finally, there is mention of open problems and opinions on future directions.