分析霍尔传感器在电气仪表中的应用研究

本文以霍尔传感器为研究对象,着眼于电气仪表工作实际,从霍尔效应及霍尔元件分析、霍尔传感器基本工作原理分析以及霍尔传感器在电气仪表中的应用分析这三个方面入手,围绕这一中心问题展开了较为详细的分析与阐述,并据此论证了霍尔传感器装置的应用在进一步提高电气仪表工作质量与工作效率的过程中所起到的至关重要的作用与意义。     

A “Pure” long-term interest rate and the demand for money

This article presents the appropriate rate by which to discount a constant, certain, infinite stream of future payments: that is, the yield on a noncallable perpetuity or consol. The American consol series is a daily risk-free “pure” long term interest rate which is undistorted by tax effects, call premiums, and varying duration and reinvestment assumptions. If Hamburger had used the American consol series instead of the U.S. Government Long Term Bond Rate in his money demand function, he would have found more of the “missing money.” His average error (actual minus predicted money demand) as a percentage of actual money demand would have been reduced from 1.43% to 0.93% a 35% error reduction.     

The medical expense deduction and income levels: Progressive or regressive?

The medical expense deduction (MED) allows taxpayers to deduct from taxable income a proportion of their out-of-pocket medical insurance and health care expenses. Because the rate of subsidy is equal to the marginal tax rate previous studies have found MED to be a regressive tax mechanism biased toward benefiting higher-income taxpayers. The authors demonstrate, using GINI coefficients, that MED makes the tax structure more progressive than it would otherwise be and increases equality of after-tax incomes.     

Ownership dispersion as a second-best counterstrategy against monopoly

A literature on second-best pricing as counterstrategy against monopoly has evolved in economics. The purpose of this paper is to demonstrate that ownership dispersion through forced divestiture can be more effective in restricting the social damage of monopoly. Economists generally hold an ordinal view of utility. To the extent that the second-best literature suggests the possibility of reducing dead-weight loss through counterpricing, most economics would accept counterpricing as welfare increasing and reject ownership dispersion. The example presented in this paper suggests that this mindset may cause us to overlook promising alternatives.     

极区电离层电导率的冬季异常行为研究

从电离层电导率的理论研究出发,利用国际参考电离层模型IRI-2007,分析了地磁平静情况下,一个完整的太阳活动周期内,极区电离层Pedersen和Hall电导率在太阳活动上升相、下降相和高年的变化情况。研究表明,受太阳及地磁活动的影响,和电离层电子密度一样,极区电离层电导率具有明显的季节性特征,电导率在中、高纬地区均伴有比较明显的冬季异常行为。     

基于霍尔三维结构的高校科技成果推广转化系统模型

基于"霍尔三维结构"理论,提出了高校科技成果推广转化的三维结构。在对高校科技成果推广转化每一维度进行系统分析的基础上,最终给出了高校科技成果推广转化的系统模型。     

Let's make a deal in the classroom: Institutional solutions to the Monty Hall Dilemma

The authors describe how the Monty Hall Dilemma, a well-known choice anomaly, can be demonstrated with a simple and versatile classroom experiment. In addition to demonstrating the anomaly, the experiment can be used to introduce students to some institutional modifications that have been shown to ameliorate it. This experiment, which can be tailored by instructors to meet specific learning objectives for a variety of courses, can also be used to frame broader discussions about rationality, institutions, and choices under uncertainty.     

Scientific and technical planning in the People's Republic of China

At a time when Western market economies are struggling with ways of directing and stimulating technological innovation, China, with a highly centralized system for the planning and coordination of science and technology, offers an unusual perspective on the feasibility and operations of a large-scale, national organization of scientific and technical resources. This paper describes the mechanics of the science and technology planning process in the Chinese system and then draws conclusions on a variety of pertinent issues, such as: whether or not planning is actually conducted at a macrolevel; what are the useful sources of information for scientific and technical decision making within the system; what are the motivations for doing research in China's planned economy and how do they affect the research that is done; and, in summation, does the Chinese attempt at macroscience and technology planning really work?     

MRO parts service in the machine tool industry

This article examines the post purchase Parts servicing of Machine Tools. Survey results outline the policies and criteria that influence the degree to which replacement parts will be provided for old machines. The survey indicates that the policies of some American manufacturers leave service gaps that can be exploited by foreign as well as domestic competitors.