排序方式: 共有170条查询结果,搜索用时 0 毫秒
21.
孙国华 《中国教育技术装备》2005,(3):14-14
我们经过反复实践修改,设计了一种用白炽灯和经过改造的拉线开关(简称三线三位开关)实现软启动的装置,经过使用效果很好。使多台旧投影仪焕发青春。电路原理如图1。 相似文献
22.
23.
24.
25.
27.
叶甘露 《中学物理教学参考》2009,(10):33-34
人教版高中《物理》必修加选修第17章“交变电流”第三节“电感和电容对交变电流的影响”安排了一个电感对交变电流的阻碍作用的演示实验,原理如图1所示,电感线圈和白炽灯泡串联在电路里,利用双刀双掷开关S可以分别把电路接到直流电源或交流电源上, 相似文献
28.
张善能 《数理天地(初中版)》2010,(5):46-47
白炽灯可将电能转化为光能,工作原理是:电流通过灯丝时由于热效应产生热量,螺旋状的灯丝不断将热量聚集,温度达2000℃以上,灯丝处于白炽状态而发光.白炽灯必须在高温下才能发光,但是,在高温下灯丝容易氧化和升华,当灯丝经长时间使用变得比较细时,就很容易烧断.为了延长灯泡的使用寿命,人们经过了漫长的探究之路. 相似文献
29.
1制作材料废白炽灯泡1只、透明的塑料或玻璃小瓶(瓶高70cm左右,带有塑料瓶盖)1个、废弃节日小彩灯1只(能正常发光)、导线2根等。2制作方法①制作电极:打破白炽灯泡,用钳子去掉钨丝和金属丝扣,取出镶有两根金属电极的玻璃灯芯,在灯芯上面的两电极丝处各套上一段绝缘导线皮,作为导电性实验的电极用(如图1)。 相似文献
30.
A 3D numerical simulation of laser-induced incandescence of soot particles in coal combustion products 总被引:1,自引:0,他引:1
Gérard GREHAN 《浙江大学学报(A卷英文版)》2009,10(9):1320-1326
Laser-induced incandescence (LII) has received increasing attention as a potentially powerful technique for in-situ measuring of the volume fraction and primary size of soot particles in combustion systems. In this study, a 3D Monte Carlo simulation combined with a Mie equation was developed to analyze the influence of spectral absorption and scattering on the measured LII flux emitted by soot particles. This paper represents a first attempt to analyze soot measurement using the LII technique in coal combustion products. The combustion products of gases (CO2, N2), soot, and fly-ash particles, present between the location of laser-excited soot and the LII flux receiver. The simulation results indicated that an almost Beer-Lambert exponential decrease in LII flux occurred with an increase in the volume fraction of soot particles, while a nearly linear decrease occurred with an increase in the volume fraction of fly-ash particles. The results also showed that scattering effects of both soot and fly-ash particles on the LII flux could be neglected. Compared with the absorption of gases, a decrease of 20% of LII flux was observed with soot particles, and a decrease of 10% with fly-ash particles. 相似文献