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1.
本介绍了用磁场能量计算磁力的方法,并利用这方法证明了两个载流闭合回路之间的磁力遵从牛顿第三定律。  相似文献   

2.
在电磁感应现象中,动生电动势是由电荷受到洛仑兹力的作用而产生的;从能量的观点看,电源的能量是由洛仑兹力对电荷作功转化而来的.  相似文献   

3.
通过分析浮环所磁力,指出浮环之所以能够跳起或呈悬浮状,交不是因为环上的电流与线圈的电流方向相,反而是由于环上电流与电动势之间的相位差。  相似文献   

4.
直流电动机工作原理是利用通电线圈在磁场中受磁力的作用,在磁力矩作用下使直流电动机转动。由于直流电动机在工作时产生自感电动势,欧姆定律是不适用,因此处理方法与直流电路有很大不同,往往借助能量关系,并利用串并联电路的电压、电流关系求解。  相似文献   

5.
功是物理学中最基本、应用最广泛的概念之一,其实质是能量改变的一种度量。然而长期以来,不同教科书对作功却有不同的定义方式,认识也不尽一致。本文拟以摩擦力作功问题为例,就研究对象可否视为质点两种情况给出了功的较为合理的定义。  相似文献   

6.
在日常生活中,原本磁力很强的磁铁由于大强磁场的环境下磁力的方向以及大小会发生变化,例如小磁铁在两块大磁铁的干扰下磁力会有所减弱;磁铁放在炉子旁,在高温环境下,磁力会有所减弱;铁钉被吸附在磁铁上,经过一段时间后会有磁性。这些都是为什么呢?我们查阅了许多资料,知道每一块磁铁都有不同的居里温度(Curie Temperature),即磁铁在该温度下会失去磁性,而我们常见到的磁铁的居里温度是多少呢?磁力的变化有什么用处?  相似文献   

7.
讨论了低速情况下,动生电动势,感生电动势的相对性及对相互转化。  相似文献   

8.
本文根据磁力搅拌器的工作特点,提出了一种行之有效的控制方法,并用单片机加以实现,实现了磁力搅拌器的智能化。  相似文献   

9.
《力矩作功与刚体绕定轴转动的动能》教学纪实与实析许弘黑龙江省电力职工大学韩春元老师,讲授“力矩作功与刚体绕定轴转动的动能”(注)一课,受到好评.授课伊始,教师首先引导学员复习与本课有关的知识;力矩、力的功、功率、平动动能、动能定理、刚体转动定律等,并...  相似文献   

10.
在稳恒磁场中运动的导体内产生感应电动势,称之为动生电动势;另一种是导体不动,因磁场的变化产生的感应电动势,称之为感生电动势。  相似文献   

11.
汉字倒说     
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。  相似文献   

12.
《海外英语》2007,(5):44-45
It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,  相似文献   

13.
钱生钱!     
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了  相似文献   

14.
《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.  相似文献   

15.
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex.  相似文献   

16.
王菲 《华章》2007,(12):273-273
Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.  相似文献   

17.
现在,我们可以没有面包,没有钱,没有房子,没有车子……但我们唯独不能丢失的是高尚的情操,笃定的信念,还有,满满的希望!  相似文献   

18.
Using virtual reality for interactive design gives a designer an intuitive vision of a design and allows the designer to achieve a viable, optimal solution in a timely manner. The article discusses the process of making the Virtual Reality System of the Humble Administrator's Garden. Translating building data to the Virtual Reality Modeling Language (VRML) is by far unsatisfactory. This creates a challenge for computer designers to do optimization to meet requirements. Five different approaches to optimize models have been presented in this paper. The other methods are to optimize VRML and to reduce the file size. This is done by keeping polygon counts to a minimum and by applying such techniques as object culling and level-ofdetail switching.  相似文献   

19.
钱微 《华章》2007,(3):124-124
The awareness of individualism can be traced back to the period of American Revolution when the Declaration of Independence was produced.It expressed basic beliefs concerning freedom,equality,democracy,privacy and the relationship between people and government,which were exactly what the philosophy of individualism mostly dealt with at that time.This paper is to exploit the essence of individualism by analyzing the Declaration .The analysis enables us to reconsider its significance to the issue of America human rights and foreign policies.  相似文献   

20.
裴水妹 《华章》2007,(11):196
Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.  相似文献   

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