共查询到20条相似文献,搜索用时 84 毫秒
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电磁感应定律演示实验的改进 总被引:1,自引:0,他引:1
电磁感应定律演示实验的改进高俊发(辽宁省林业学校,沈阳110101)在电磁感应定律教学中,多数教师采用示教电流表和固定式多匝线圈,手握磁铁来定性演示电磁感应定律.我用大型光点检流计取代示教电流表,配用自制装置定量地演示了电磁感应定律,收到了满意的教学... 相似文献
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电磁感应定律实验新探 总被引:2,自引:1,他引:1
针对传统电磁感应定律无法量化研究的缺点,对电磁感应实验进行了改进.以电动机及传送带驱动小磁铁穿越线圈,电磁感应发生的过程被电脑录音软件Cool Edit Pro 2.0实时录制为脉冲电流频谱.依据脉冲电流频谱的间隔及宽度,可调控并测定小磁铁穿越线圈的速度及电磁感应发生的时间;依据脉冲的振幅,可判断感生电动势的大小,进而探究或验证电磁感应定律. 相似文献
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法拉第电磁感应定律的验证 总被引:4,自引:1,他引:3
一、实验装置文献[1]中描述了一种实验装置用于验证法拉第电磁感应定律.本文对实验装置进行了改进,重复了这个实验,并进行了更详细的实验分析,得到了一些结论,可以使学生加深对法拉第定律的认识和理解.图1实验装置示意图1.磁棒2.玻璃管3.线圈支架图1所示为我们的实验装置示意图.在一个有机玻璃管壁上均匀地刻5个槽,制成一个线圈支架.用AWGti36细铜线在槽上分别密绕5个独立的线圈,线圈宽度为4.0mm,直径为1.80cm,匝数分别为N1=30,40,50,60,70.该线圈支架套在一个刻有标度的玻璃管(内直径为1.10cm,管壁厚1.5mm)上… 相似文献
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如果说磁体和线圈相对静止可以输出电能,或许谁都不会相信,因为法拉第的电磁感应明确表明相对运动是最重要的。如果说在相对静止的磁体和线圈之间有一个圆筒转子,转子上有两个对称的孔(起到漏磁作用),这两个孔正好与磁体和线圈同心,电磁感应规律证明这的确是一台发电机。 相似文献
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The mechanisms of ion-stimulated desorption of thin organic overlayers deposited on metal substrates by mono- and polyatomic projectiles are examined using molecular dynamics (MD) computer simulations. A monolayer of polystyrene tetramers (PS4) physisorbed on Ag{1 1 1} is irradiated by 15 keV Ga and C60 projectiles at normal incidence. The results are compared with the data obtained for a benzene overlayer to investigate the differences in sputtering mechanisms of weakly and strongly bound organic molecules. The results indicate that the sputtering yield decreases with the increase of the binding energy and the average kinetic energy of parent molecules is shifted toward higher kinetic energy. Although the total sputtering yield of organic material is larger for 15 keV C60, the impact of this projectile leads to a significant fragmentation of ejected species. As a result, the yield of the intact molecules is comparable for C60 and Ga projectiles. Our data indicate that chemical analysis of the very thin organic films performed by detection of sputtered neutrals will not benefit from the use of C60 projectiles. 相似文献
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根据电磁线圈炮中推力线圈与电枢之间的感应耦合方程和电枢动态响应方程,考虑发射过程中推力线圈和电枢的欧姆加热,开发了电磁线圈炮的计算程序,给出了程序的算法和流程。分析了程序的收敛性,认为最大时间步长和电枢最大网格均依赖于驱动脉冲波形的上升时间。通过模拟结果与单级线圈炮实验测量结果的比较,验证了程序的有效性。模拟的线圈电流波形与实验波形吻合较好,模拟的出口速度比测量速度大约6.5%。程序收敛性和有效性的验证表明该程序可用于电磁线圈炮系统的初步设计。 相似文献
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针对同步感应线圈炮常用的导体圆筒式电枢,结合电流丝法,建立了电枢温升计算模型;通过搭建三级同步感应线圈炮试验平台,验证了计算模型的正确性,并分析了电枢材料和剖分设置对电枢温升计算的影响。结果表明:发射过程中电枢的最高温升位于其底部外侧,电枢前端也有较高温升;当调节载荷使铜、铝电枢等质量时,前者的温升虽然更高,但温升对其发射效率的影响却小于后者,这是因为铜的电阻率温度系数小于铝;电枢的剖分设置对电枢温升的计算的影响比较明显。因此从电枢温升对发射过程的影响来看,铜电枢比铝电枢更适合用于高速发射。 相似文献
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基于电路理论,建立了多级感应线圈炮数学机电控制模型;分析了电枢受力的影响因素,结果表明,电枢受力决定于驱动线圈和电枢的电流大小和它们之间的互感梯度。总结了多级同步感应线圈炮设计原则,根据设计原则,提出了感应线圈炮的最优发射控制策略,并从理论上证明其可行性,最后以10级线圈炮为例,归纳了多级感应线圈炮的触发公式,并进行了实验验证,其结果表明,通过修正触发公式,仿真结果与测量值吻合较好。 相似文献
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针对同步感应线圈炮常用的导体圆筒式电枢,结合电流丝法,建立了电枢温升计算模型;通过搭建三级同步感应线圈炮试验平台,验证了计算模型的正确性,并分析了电枢材料和剖分设置对电枢温升计算的影响。结果表明:发射过程中电枢的最高温升位于其底部外侧,电枢前端也有较高温升;当调节载荷使铜、铝电枢等质量时,前者的温升虽然更高,但温升对其发射效率的影响却小于后者,这是因为铜的电阻率温度系数小于铝;电枢的剖分设置对电枢温升的计算的影响比较明显。因此从电枢温升对发射过程的影响来看,铜电枢比铝电枢更适合用于高速发射。 相似文献
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从麦克斯韦方程组和导热微分方程出发,导出了3维多级感应线圈炮电磁场、温度场分布的基本方程,并以电磁场和温度场有限元分析为基础,建立了3维有限元分析模型,忽略级间的相互影响,多级线圈炮中电枢温升可以等效为多个单级电枢的温升,运用通用有限元分析软件ANSYS的耦合计算流程,对单级感应线圈炮中电枢电磁场和温度场进行仿真。计算中考虑了材料物理参数随温度变化对温度场的影响。仿真结果表明:电枢内的温升主要分布在电枢的外表面和尾部;电枢的温度随着电容器组电压和电容增加而升高,这是因为总能量增大,电枢中涡流也增大,从而电枢的温度升高;电枢的触发位置和速度匹配关系,也会对电枢温升造成很大的影响;电枢的温度随着级数的增加逐渐升高,说明电枢在一定级数后达到了材料的熔点而被破坏。 相似文献
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Abstract A 60 cm long, 6 mm square bore railgun has recently been developed in pursuance of the impact fusion and related studies. Nylon projectiles (with 0.1–0.3 g mass), successfully accelerated using ~ 1 mm thick aluminum/copper metallic armatures, are recovered with front surface quite intact but slightly damaged on the back side. In the initial experiments so far, the final velocity of projectiles has been determined simply from their impact onto solid blocks and measuring the consequent displacement. The velocities of 0.2–0.5km/s so estimated, are generally in agreementwith the results expected on the basis of a simple zero-dimensional numerical simulation of the capacitor-bank driven railguns. Techniques to accurately monitor the in-bore and final projectile velocities are being tested and implemented. A maximum velocity of ~ 2 km/s for 0.5 g mass projectiles is expected after certain improvements in the system parameters. 相似文献
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The neutralization of C(60)(+) and C(60)(2+) fullerenes with keV energies is studied for grazing scattering from a clean and flat Al(001) surface. From the measured shifts between the angular distributions for scattered projectiles of different incident charge, we derive image-charge interaction energies, which relate to the distances of electron transfer for C(60)(+) and C(60)(2+). These neutralization distances are in accord with a classical over-the-barrier model taking into account the image-charge effects of the Al target and the polarization of the fullerene. 相似文献
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Initiation of detonation by conical projectiles 总被引:2,自引:0,他引:2
Initiation of detonation by a hypersonic conical projectile launched into a combustible gas mixture is investigated. From analytic considerations of the flowfield, energetic and kinetic limits are proposed to predict the conditions required to initiate an oblique detonation wave in the mixture. To experimentally investigate these limits, projectiles with cone half angles varying from 15° to 60° were launched into a stoichiometric mixture of hydrogen/oxygen with 70% argon dilution at initial pressure between 10 and 200 kPa. The projectiles were launched from a combustion-driven gas gun at velocities as great as 2.5 km/s (corresponding to 150% of the Chapman Jouguet velocity). Pictures of the flowfields generated by the projectiles were taken via schlieren photography. Five combustion regimes could be observed about the projectile ranging from a prompt and delayed oblique detonation wave formation, combustion instabilities, a wave splitting, and an inert shock wave. The two theoretical limits provide a means to interpret the observed flowfield regimes and are in satisfactory agreement with the experimental results. 相似文献