Powerline Frequency Electric and Magnetic Fields: A Pilot Study of Risk Perception

The perception of the potential risk arising from human exposure to 50/60 Hz electric and magnetic fields was studied with a quasi-random sample of 116 well-educated, opinion leaders using the risk perception framework previously developed by Slovic, Fischhoff, and Lichtenstein. These individuals rated exposure to fields from transmission lines and electric blankets on a variety of scales that have been found useful in characterizing people's risk attitudes and perceptions. These judgments allowed us to conjecture about the likely desire for regulation of these potential hazards and the likely response to a publicized problem (e.g., an accident or ominous research finding) involving these two sources of exposure. Various forms of detailed information about 50/60 Hz fields were supplied to respondents. The provision of information produced modest, but statistically significant, changes in perceptions in the direction of greater concern about the risks. In response to questions of public policy, participants desired modest regulatory control of field exposure from transmission lines and little or no control of field exposure from appliances like electric blankets.     

VTR走带系统的齐次坐标变换

提出了一种分析磁带录像机(VTR)螺旋扫描走带系统设计参数、坐标计算及描述误差传递的数学方法.这种方法系统性强并有利于编程计算,已应用于本校录像系统生产技术研究院机电一体化研究室的研究工作,是空间复杂问题分析的一种有效方法.     

磁粉温度稳定性测量装置及测量方法

我们利用冲击差值补偿法,建立了一台测量磁粉温度稳定性的装置.该装置的灵敏度为2.1×10~4/mm,测量重复性为8×10~5.我们使用该装置测量了γ-Fe_2O_3等几种磁粉在使用温度范围附近的可逆和不可逆变化.包钴和掺钴的γ-Fe_2O_3磁粉的变化规律与报道的相符.对于普通的γ-Fe_2O_3,当温度从20℃上外到80℃时,剩余磁感应强度 Br 减少了5%;在这个温度范围内经五次循环以后,剩余磁感应强度随温度的变化是可逆的,其温度系数-5×10~4/℃.     

论武汉人文化品格

在则厌倦,离则怀念是武汉及武汉人给时人的一种感受.斥力与魅力的互融是武汉人文化品格之所在:内敛、疏离、情绪化和世俗的趋向使武汉人缺失一股张力而生排斥;宽容、重情与开拓情怀则让武汉显得包容而有吸引力.斥力的调适与魅力的传扬是使武汉走出"在则厌,离则念"怪圈、弘扬武汉文化与光大武汉人形象的良好选择.     

基于人才集聚载体的人才吸引力研究——以辽西北地区为例

突破辽西北战略需要人才集聚支持。本文建立了由主体载体、服务载体、保障载体组成的人才集聚载体体系,总结人才吸引力影响因素,借助系统动力学建立人才集聚载体与人才吸引力的互动关系模型,并结合辽西北地区进行模拟分析,从建设人才集聚载体的角度提出增加辽西北地区人才吸引力的措施。     

磁调制式直流放大器的静态性能分析

介绍了磁调制式直流放大器的构成,围绕提高磁调制器的性能进行了讨论,给出调制器的灵敏度与其结构尺寸及信号绕组匝数之间的关系,并确定了获得最高灵敏度应满足的条件。根据减小噪声和漂移、提高灵敏度的要求,分析了磁调制器铁芯应采用的结构型式。     

A local moment type estimator for an extreme quantile in regression with random covariates

A conditional extreme quantile estimator is proposed in the presence of random covariates. It is based on an adaptation of the moment estimator introduced by Dekkers et al. (1989 Dekkers, A.L.M., Einmahl, J.H.J., de Haan, L. (1989). A moment estimator for the index of an extreme-value distribution. Ann. Statist. 17:1833–1855.[Crossref], [Web of Science ®] , [Google Scholar]) in the classical univariate setting, and thus it is valid in the domain of attraction of the extreme value distribution, i.e., whatever the sign of the extreme value index is. Asymptotic normality of the estimator is established under suitable assumptions, and its finite sample behavior is evaluated with a small simulation study, where a comparison with an alternative estimator already proposed in the literature is provided. An illustration to a real dataset concerning the world catalogue of earthquake magnitudes is also proposed.     

中国与希腊神话美之比较

中国、希腊远古神话描述出当时时代所能认识的自然世界的形态,实现了自然美与社会美的结合、现实美与艺术美的统一,这是东西方两个民族神话共同的美学精神内涵。由于各个民族地理环境、气候特征、物产资源等的不同,东西方神话形成了不同的风格:中国神话歌颂劳动,赞美意志,表现强烈的正义感和献身精神,具有理性、严肃的恬静美;而希腊神话则讴歌冒险,崇尚肉体,具有热情、粗犷、险峻的紧张美。不同神话风格的由来,是不同民族不同生存条件、心理定势、价值取向、行为模式等因素交互作用、彼此影响所形成的。