共查询到20条相似文献,搜索用时 93 毫秒
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本文对弦的横振动方程进行了严格推导,得出波速的解析解,并在共振时测量了波长和共振频率的实验值,理论与实验相吻合.本文对杆的横振动方程亦进行了严格推导,对一端卡住、另一端自由时进行了数值求解,得出共振时容许的前几个本征频率的表达式及相应共振波节位置,给出通解,实验中测出了不同长度时不锈钢薄细长条的基频及前几阶泛音共振频率,测出的波节位置与理论值一致,并求出不锈钢长条的杨氏模量,与标准值相符.进一步推广到圆形钢丝环的小振动情形,实验上测出了圆环共振时的频率及波长,求出截面为圆形的细钢丝的杨氏模量,与现有值基本符合. 相似文献
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前 言 目前各高等学校的普通物理实验中,几乎都开“金属材料杨氏模量的测定”这个实验.它是将力加在试样上,测出相应的应力和应变,从而计算出杨氏模量来.这种方法属于静态法通常用于大变形和常温下的测量,它的缺点是由于载荷大、加载速度慢.含有弛予过程,它不能很真实地反映材料内部结构的变化.对脆性材料也难以用静态法测量,也不能测量高温下材料的杨氏模量.本文介绍的动态法可以克服上述缺点,具有实用价值[1]。 本实验的基本方法是将一根试样(圆棒或矩形棒)用两根悬线悬挂起来并激发它作横振动,在一定条件下试样振动的固有频率取决于它的… 相似文献
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在共振法测量杨氏模量实验中,为了获得更精确的共振频率,使用基于声卡的虚拟信号发生器代替FB209动态杨氏模量测试仪,用虚拟示波器代替普通示波器,提高了测量信号的精度,帮助学生更好地理解和掌握实验. 相似文献
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A family of Riemannian metrics on the moduli space of irreducible selfdual connections of instanton numberk=1 overCP
2 is considered. We find explicit formulas for these metrics and deduce conclusions concerning the geometry of the instanton space. 相似文献
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A model calculation of a two-wire Josephson transmission line with a quasi-transverse electromagnetic wave is performed. The dispersion characteristics of the wave are estimated. The group velocity is shown to be (4.1–2.5)·107 m/s for a temperature of 76–85.9 K, a critical current of 109 A/m2, a dielectric plate thickness of 10 m, and a relative permittivity of 40. The wave attenuation in this temperature range is 2 db/dm at a frequency of 10 GHz. The rough estimates suggest the feasibility of designing microstrip transmission lines based on granular high-temperature superconducting films. These lines will provide delays up to 1 s and picosecond pulse transmission. 相似文献
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刘克玲 《光谱学与光谱分析》2003,23(3):446-450
在 0~ 80 0nm光谱范围 ,观察发现了原子光谱线位移与波长、温度、湿度及压力变化之间的非线性函数关系 ,绘制了它们之间的非线性函数关系曲线 ,给出了表达方程式 ;实验证实这些非线性函数关系对不同类型的光谱仪具有普遍适用性。观察发现了原子光谱线半宽度与温度变化之间的非线性函数关系。利用以上发现 ,开发了电感耦合等离子体光谱仪的智能波长校正装置和方法。实践证明 ,该装置和方法能有效地校正波长。 相似文献
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Band Model for Modified Lorentz Lines 总被引:1,自引:0,他引:1
A random model for band absorption is applied to modified Lorentz lines. Simplified expressions of the averaged equivalent
width are derived for the exponential and Malkmus distributions of the line intensities. It is shown that linemixing effects
are significant when the product of the coupling coefficient and absorber concentration is large. This model is applied to
the 5.3 mm band of NO. 相似文献
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Ultranarrow Spectral Lines via Quantum Interference 总被引:2,自引:0,他引:2
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WavelengthsofFiveNi-LikeLaserLines¥G.X.Chen;Q.Y.Fang;W.Cai(InstituteofAppliedPhysicsandComputationalMathematicsP.O.BOX8009Bei... 相似文献
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Bityukov V. K. Gorbunov R. A. Simachkov D. S. Frunze A. V. 《Optics and Spectroscopy》2019,126(4):450-453
Optics and Spectroscopy - In spectroscopy, hollow cathode lamps are subject to increased requirements for radiation parameters. To check spectrometric equipment, it is necessary to create a highly... 相似文献
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This article presents the control of adjustable true time delays applied to an optical beamforming system. First is introduced the response of ring resonators of two and four ports and the cascade and lattice structures. The coupling factor and the phase modulation are employed as the control parameters for the adjustable group delay. The strategy of control is proposed and applied to a cascade of five ring resonators for producing wideband true time delays in the picosecond–nanosecond range with 2-GHz bandwidth and extremely low ripple. Ripples lower than 0.1% were obtained for the adjusted group delays. The proposed strategy can be simply extended if more resonators are added to increase the bandwidth of the system. 相似文献