似稳条件下磁通量计算与中空螺旋管式无极灯

似稳条件下磁通量计算与中空螺旋管式无极灯

阳宾1陈奋策2

(1.厦门大学嘉庚学院机电工程系，福建漳州363105；2.福建教育学院理科研修部，福建福州350025)

摘要：在似稳状态下，从电磁理论出发，讨论通过某一回路曲面的磁通量的计算、法拉第电磁感应定律；并应用于中空螺旋管式线圈无极灯能量耦合机制和结构的探究，以使增大其有效磁通量，提高对电子有效加速，最终提高其发光效率的有效途径。

关键词：似稳状态；磁通量；法拉第电磁感应定律

作者简介：阳宾(1983-)，男，广西桂林人，厦门大学嘉庚学院机电工程系助理工程师。

中图分类号：O441.3文献标识码：A

1引言

电磁学中似稳电路的必要条件[1，2]

λ>>l，T>>l/c,ω=wπf<<2πc/l

①

其中f是电源的频率，T周期，l电路(电子仪器)的尺寸，λ电磁波的波长；似稳电路还需满足充分条件，即似稳交流电路中的元件把电磁场集中在自己内部小范围内。

似稳电路中，以电源的圆频率变化的电流通过导体，在导体周围会形成交变的电磁场，即电磁波；在此以光速c传播的电磁波及其变化传遍整个电路所需要的l/c时间内，电磁波的位相近似不变；每一时刻电磁场的分布与同一时刻的电流、电荷的分布的关系，近似和稳恒电路一样，一起同步地做缓慢的变化。

文章在似稳近似下，以工作频率在230KHz左右一种最近实用新型专利[3]提出的中空螺旋管式线圈无极灯为例，从电磁理论高度讨论无极灯螺旋管产生的磁通量分布与计算，以及对灯泡内电子有效加速情况。

2似稳条件下磁通量计算

2.1磁通量的物理图像

②

在经典物理中[2，4]，法拉第电磁感应定律表述了产生的感应电动势与磁通量的关系。磁通量Φ的定义为覆盖某面积的磁场的积分：

③

④

2.2.1似稳状态下交流电流产生的磁场

⑤

例如，图1示意通以似稳交流电流的螺绕线圈和其产生的磁场。

图1

2.2.2似稳条件下磁通量的计算

相似于似稳状态下交流电流产生的磁场的讨论，公式③④⑤在似稳条件①下都成立，似稳状态下磁通量的计算可以延用公式③，即：

③

3似稳条件下磁通量的计算与应用

3.1外置型中空螺旋管式线圈产生的磁场分布

现以磁环外置型中空螺旋管式无极灯为例，如图2所示，实用新型专利[3]一种新型节能无极灯，在灯座1上设置一射频功率源2；射频功率源上设置有两端非封闭的灯壳3、中空玻璃管4，中空玻璃管内设置有中空铁磁芯5，中空铁磁芯缠绕有通电线圈6；中空玻璃管两端与灯壳密闭连接形成灯管7；中空铁磁芯中心两端连通空气。图2是实用新型实施例结构示意图。

图2

一般实验室电子仪器的尺寸或用电器如无极灯)的尺寸l为几厘米到几十厘米的量级，例如80瓦无极灯电源频率f=230kHz<

B=μnl0

⑥

图3是螺绕管式线圈在磁棒内外的交变磁场线分布(理想化)与磁棒四周的环路示意图。

图3

3.2穿过螺绕管式线圈-磁棒四周环路的磁通量

3.3提高有效磁通量的途径与作用

我们知道，无极灯主要由频率发生器、功率耦合器和玻璃泡壳三部分组成，通过电磁感应方式将能量耦合到灯泡内；灯泡内充有适量的特种气体，耦合到灯泡内的高频能量使之电离或激发，激发后的原子从较高能级返回基态时，发出紫外光子，紫外光子激发泡壳内壁的荧光粉产生可见光。

根据前面的讨论，穿过环路的磁通量不同，在环路上产生的交变电场也不同，对灯泡内电子的加速效果也不同，导致荧光粉产生可见光的效果也不同。改变灯的结构和形状，可以使回路中有最佳的有效磁通量，从而得到最近的交变电场，提高对电子的加速效果(减少电子无效的热运动)，最终提高发光效率。实用新型专利[3]中空螺旋管式无极灯的结构设计正是为了克服市面上灯泡型无极灯存在的缺点：通电线圈外磁力线分布不合理，降低了灯壳内有效的磁通量和有效交变电场，导致降低对灯壳内电子的有效加速效果，因而降低灯的发光效率。

另外，该实用新型中空的铁磁芯直接连通空气，对磁芯的散热快，及时降低磁芯的温度，提高磁芯的耦合效率，从而提高发光效率；另外还可降低成本。

以上从电磁理论高度，在似稳近似下，探究似稳交变电流产生的磁通量计算原则，探究法拉第电磁感应定律的形式；并应用于中空螺旋管式无极灯的结构设计，提出提高有效磁通量，以提高其发光效率的有效途径。

参考文献：

[1]陈奋策.似稳条件与无极灯工作原理[J].福建教育学院学报，2014(6).

[2]赵凯华，陈熙谋.电磁学[M].北京:人民教育出版社,1978.

[3]陈奋策.实用新型专利“中空螺旋管式线圈新型节能无极灯”(专利号：中国,ZL201420220738.4)[P].

[4]郭硕鸿.电动力学[M].北京:高等教育出版社,1997.

On Approaches to Constructing New Ideological and Political Modes in Vocational Colleges Centering on Professional Quality Culture

LIN Bing-zhiLIN Hai-rongCHEN Shu-fang

(Fuzhou Polytechnic，Fuzhou 350108，China)

Abstract：Based on actual situations, this paper proposes the necessity of constructing vocational colleges’ new ideological and political education modes centering on professional quality culture and approaches to their construction. It also puts forward the strengthening of the building of the teaching forces to improve the level of education; the enriching of the content of ideological and political education combining professional quality culture; the enhancing of mental health education to improve the students’ psychological quality; the using of campus culture as the basis to strengthen the training of professional quality; and the strengthening of social practice to enhance the education of the students.

Key words：higher vocational colleges; professional quality culture; ideological and political education; approach

Changes of the Creation of Female Novels Since the Late 70s of the 20th Century

LIN Shan

(Fujian Open University, Fuzhou 350003, China)

Abstract：Since the late 70s of the 20th century, the creation of female novels has gone through the four stages of renaissance, development, change, and expansion. Respectively, they expressed enlightenment narrative full of humanity feelings, gender narrative full of female consciousness, physical narrative full of “private” characteristics, underclass narrative and historical narrative full of femininity.

Key words：enlightenment narrative; gender narrative; physical narrative; underclass narrative; historical narrative

The Culture of Pleurotus Liquid and the Analysis of Extracellular Polymeric Substances

YI Jun1CHEN Ti-qiang2

(1. Department of Science Research and Training，Fujian Institute of Education，Fuzhou 350025，China；

2. Edible Fungi Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350013, China)

Abstract：To ascertain the effect of different carbon and nitrogen sources on the mycelial growth of Pleurotus tuber-regium (Fr.) Singer, the exo-polymers dynamic accumulation and its chemical composition. By liquid fermentation, the results showed that the mycelial growth was better in the medium of fructose as the carbon source than that of glucose as the carbon source, with biotransformation rate of 37.18～48.53%, and mycelium (lyophilized) yield 12.64±0.41～16.50±0.51 g / L; the mycelial growth in the medium of yeast powder as nitrogen source was better than that of peptone as nitrogen source, with biotransformation rate 28.06～33.68%, mycelium yield 9.54±0.79～11.45±0.73g / L. After 6～14d or 6～20 d inoculation, the exo-polymer has a smooth high level contents. The exo-polymer content (0.12～0.16g / L) in Gpy (glucose-yeast) medium was significantly higher than that in Fpy (fructose-yeast) medium (0.11～0.12g / L).GC was used to analyze the monosaccharide in the exo-polymer. The results showed that the exo-polymer was a heteropolysaccharide, and its monosaccharide composition included glucose, mannose and galactose. The exo-polymer yield was higher than the total weights of its monosaccharide. In this study, Fpy medium can be used to increase the mycelia yield, and Gpy medium to increase the exo-polymer yield.

Key words：Pleurotus tuber-regium; liquid culture; mycelium yield; exo-polymer; component analysis