共查询到19条相似文献，搜索用时 125 毫秒
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冲击电流计的灵敏度高,它不能直接用来测电流,只能用来测量短时间内脉冲电流迁移的电量。所以当实验者怀疑冲击电流计有问题时,不能直接用万用表来检查,而只能采用其它的方法。这给实验者带来很大的不便。 本文介绍一种快速检查冲击电流计是否损坏的方法,方便实用,可节省实验者的时间。方法如下,将冲击电流计的两接线端从所接的线路上拆下,用干净的纸或布擦干净。然后将两端接触放入口中或与稍热的物体接触。如果这时 相似文献
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刘晓军 《胜利油田师范专科学校学报》2001,(4)
《灵敏电流计特性的研究》实验中观察电流计的运动状态部分要求:分别观察线圈三种阻尼运动。由于李正平编的教材《新编大学物理实验》中所设计的电路图不合理,所以观察到的运动不是欠阻尼、过阻尼与临界阻尼三种运动中的一种,而是两种阻尼运动的合成情况。修改后的电路就能分别观察三种阻尼运动。 相似文献
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刘晓军 《中国石油大学胜利学院学报》2001,15(4):42-43
<灵敏电流计特性的研究>实验中观察电流计的运动状态部分要求分别观察线圈三种阻尼运动.由于李正平编的教材<新编大学物理实验>中所设计的电路图不合理,所以观察到的运动不是欠阻尼、过阻尼与临界阻尼三种运动中的一种,而是两种阻尼运动的合成情况.修改后的电路就能分别观察三种阻尼运动. 相似文献
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冲击电流计在测磁技术中的应用 总被引：1，自引：0，他引：1
张彬 《唐山师范学院学报》2005,27(5):65-66
冲击法是以电磁感应原理为基础的测量方法，用冲击电流计测定磁感应强度就是利用冲击法来实现的一种测磁技术。 相似文献
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Samples of reaches were obtained from groups of infants aged 4.5, 6, and 7.5 months. Split-screen video recordings were transcribed as sequences of (x,y,z) hand coordinates, and the hand path was examined for evidence of initial aiming and subsequent correction of the movement path. At all ages, the initial direction of the movement was correlated with target direction, providing evidence that the hand was aimed toward the target. Additionally, changes in movement direction made after the commencement of the movement tended to curve the hand path toward the target, providing evidence of error correction. Local minima of hand speed evident within segments of continuous motion were associated with turn toward the target. However, the movement path was also curved toward the target within the movement elements bounded by these minima. This finding was seen as consistent with "continuous" correction of movement errors and as contrary to the suggestion that infant movements are concatenations of ballistic movement units whose boundaries are marked by troughs in the speed profile. 相似文献
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CHEN Xiaowei LI Xiaoli 《天津大学学报(英文版)》2006,12(B09):107-111
An analytical model on the normal perforation of reinforced concrete slabs is constructed. The effect of reinforcing bars is further hybridized in a general three-stage model consisting of initial cratering, tunnelling and shear plugging. Besides three dimensionless numbers, i. e., the impact function I, the geometry function of projectile N and the dimensionless thickness of concrete target X, which are employed to predict the ballistic performance of perforation of concrete slabs, the reinforcement ratio Ps of concrete and the tensile strength fs of reinforcing bars are considered as the other main factors influencing the perforation process. Simpler solutions of ballistic performances of normal perforation of reinforced concrete slabs are formulated. Theoretical predictions agree well with individual published experimental data. 相似文献
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An analytical model on the normal perforation of reinforced concrete slabs is constructed. The effect of reinforcing bars is further hybridized in a general three-stage model consisting of initial cratering, tunnelling and shear plugging. Besides three dimensionless numbers, i. e. , the impact function /, the geometry function of projectile N and the dimensionless thickness of concrete target X, which are employed to predict the ballistic performance of perforation of concrete slabs, the reinforcement ratioρs of concrete and the tensile strength fs of reinforcing bars are considered as the other main factors influencing the perforation process. Simpler solutions of ballistic performances of normal perforation of reinforced concrete slabs are formulated. Theoretical predictions agree well with individual published experimental data. 相似文献
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吴敏 《重庆职业技术学院学报》2004,13(3):122-123
本文首先阐明了判别三相电动机绕组首末端的意义,然后着重介绍了"冲击电流法"、"交流电压法"和"剩磁感应法"判别三相绕组首末端的具体方法和原理. 相似文献
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Penetration of disk fragments following impact on thin plate 总被引：1，自引：0，他引：1
Juan-juan Li Hai-jun Xuan Lian-fang Liao Wei-rong Hong Rong-ren Wu 《浙江大学学报(A卷英文版)》2009,10(5):677-684
To investigate the ballistic resistance and failure pattern of aeroengine casing following the impact of disk fragments, and to determine the optimum case structure, the phenomena of a 1/3rd disk fragment impact on single and double-layered thin plate targets were simulated using nonlinear dynamical analysis software MSC.Dytran. Strain rate effect was introduced in a Johnson-Cook （JC） material model for the disk fragment and the plate. Impact modeling was based on the Arbitrary Lagrange-Eulerian method, and simulated using explicit finite element method （FEM）. Simulation results showed that the major failure pattern of the plate is shearing and tensile fracture with large plastic deformation. It was also concluded that the ballistic limit velocity increases with the standoffdistance when it is beyond a certain value, and that greater resistance is obtained when the front plate has either a proportionately low or high thickness. The impact resistance of a double-layered plate may exceed that of a single plate if the thicknesses and standoff distance of the two plates are set appropriately. 相似文献
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李顺芬 《昭通师范高等专科学校学报》2002,24(6):10-12
美国退出《反弹道导弹条约》目的是为其部署弹道导弹防御系统扫平道路 ,确保自己拥有对其他国家进行导弹袭击的绝对战略优势 ,从而维护其世界霸主的地位。 相似文献
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进行了29mm规格铁路车辆用GR65钢焊接性能研究,结果表明:GR65钢具有优良的抗裂性能,热影响区淬硬倾向较小。匹配WER60焊丝采用富氩气体保护焊接,焊缝组织为针状铁素体+少量的晶内先共析铁素体,焊接接头强度605MPa,焊缝-40℃冲击功达到171J,远高于技术条件要求。 相似文献
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挤进时期的航空内弹道学是研究导带嵌入炮膛时弹丸运动的阻力,它对炮管寿命的研究和保障、射击时炮管的弹道保障、炮管和弹丸本身强度的计算以及弹丸射击密集度都具有重要的影响.因此,挤进压力的计算显得尤为重要.但目前还没有令人满意的计算方法.基于此,本文引入分析法研究某型航炮的挤进压力的计算问题,这种方法计算的挤进压力与实际情况比较吻合. 相似文献
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Navinder Singh 《Resonance》2010,15(11):988-1002
A short introduction to the quantum transport in mesoscopic systems is given, and various regimes of quantum transport such
as diffusive, ballistic, and adiabatic are explained. The effect of interactions and inelastic scattering along with the characteristic
coherent effects of mesoscopic systems give interesting new mesoscopic effects, such as CoulombBlockade and Kondo Resonance.
The basic physics of these phenomena is explained in simple language. In the end, some current research problems in this field
are discussed. 相似文献