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针对现有平抛运动实验装置设计不足、操作繁琐等问题,设计了多功能平抛运动实验装置.设计制作的装置将讨论平抛运动水平与竖直分运动、演示不同高度和初速度的平抛运动、验证平抛运动轨迹是抛物线等多种功能相融合,方便实验教学的开展.通过现象的观察和数据的处理,从多角度引导学生归纳平抛运动的规律,为提升科学探究能力提供良好的教学资源. 相似文献
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平抛运动是高中物理学的一个重要知识点,做好演示实验对理解和掌握平抛运动规律是十分重要的.人教版普通高中课程标准实验教科书(必修2)第12页参考案例2中的演示装置,简便易行,它能让学生清晰地看到水流作平抛运动的轨迹.但是它无法把此轨迹保存下来进行进一步的研究.笔者经过反复实验、研究,并在它的基础上做了进一步的改进,设计制作了平抛运动轨迹演示仪,经多次使用效果很好.现介绍如下,供参考. 相似文献
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平抛运动是水平运动与竖直自由落体运动的合成,为了演示直观、生动,让学生形成感性认识,笔者制作了平抛运动分解演示器,此仪器不但可以看到三个小球同步运动,而且通过小球在运动末端时触压开关,由三个电灯燃亮的时刻,来显示同时刻水平运动的小球与平抛球在水平方向上的位移相等,平抛球与竖落球在竖直方向上的位移相等,三个球同步运动,比以往的平抛竖落仪器更直观。 相似文献
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现有的平抛运动演示仪存在实验现象不直观、操作繁琐耗时长、器材昂贵等缺点,因此,选择生活中常见的器材自制教具.巧妙地利用联动装置保证了小球同时运动,生动形象地演示平抛运动在水平和竖直方向的运动情况,同时利用磁性小球和磁性画板描绘其运动轨迹.能使学生直观明了地观察到做平抛运动的物体的运动轨迹,同时教具操作简单方便,经久耐用. 相似文献
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A 90° two-beam coupling configuration was used to store an image of an extended object in a 0.032 %wt iron-doped LiNbO3 crystal. A volume hologram was thus generated, via the photorefractive effect, within the microstructure of the crystal. The time evolution of partial spatial erasure of the hologram under illumination was studied by capturing its reconstructed image on a digital camera and performing a two-dimensional inverse Fourier transform. This produced the refractive index grating created through interference of object and reference beams. The nature, intensity distribution and dimensions of the diffraction grating were derived in order to throw light upon the movement and mechanisms of charges, which create the index grating. 相似文献
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Xanthopoulos P Mischchenko A Helander P Sugama H Watanabe TH 《Physical review letters》2011,107(24):245002
The relation between magnetic geometry and the level of ion-temperature-gradient (ITG) driven turbulence in stellarators is explored through gyrokinetic theory and direct linear and nonlinear simulations. It is found that the ITG radial heat flux is sensitive to details of the magnetic configuration that can be understood in terms of the linear behavior of zonal flows. The results throw light on the question of how the optimization of neoclassical confinement is related to the reduction of turbulence. 相似文献
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为了设计低投射比的超短焦投影物镜,本文采用自由曲面和折反式的光路结构设计了一种具有低投射比的超短焦投影物镜系统。该物镜由一个旋转对称的折射透镜组和一个自由曲面反射镜组成。采用11.938 mm的数字微镜器件(DMD)作为空间光调制器产生图像源。采用法线加权迭代优化的方法计算自由曲面。最后,分析了系统的性能。仿真结果表明:超短焦投影物镜可在580 mm的投影距离处实现3048 mm尺寸的大屏幕投影,系统的投射比低至0.19,系统的最大畸变小于0.72%。能够满足低投射比超短焦投影物镜的设计要求。该投影系统具有低投射比、低畸变、投影效果好等优点,可为超短焦投影系统的进一步发展提供有益参考。 相似文献
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本依据科氏力原理,利用数学矢量公式推断地球表面水平运动物体的偏转方向,并依据其对地球表面出现的系列现象给予物理意义上的解释,使得传统的地表水平运动物体偏转方向的判断进一步规范化。 相似文献
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A.G. Thompson 《Journal of sound and vibration》1980,70(4):481-486
Dynamic vibration absorbers should be tuned and optimally damped to control the amplitudes of vibration of the primary mass over the whole range of exciting frequencies. The lighter the auxiliary mass the greater is the amplitude of its excursions relative to the primary mass. In the case of the tuned system the maximum steady state throw of the auxiliary mass can be easily calculated from the formulas given. These are most elegantly derived by use of a frequency locus technique. It is shown that is the system is also optimally damped the throw of the auxiliary mass has its minimum value which depends only on the mass ratio. 相似文献
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提出了一种无需全息计算和相干照明的衍射投影方法和投影系统,利用非相干的准直LED光源和傅里叶变换透镜取代全息迭代计算获得被投影图像的空间频谱,再利用空间频谱在自由空间中的瑞利索墨菲衍射实现了小投射比、无限景深的图像投影.详细推导了投影方法的成像过程,解析了投影系统的强度脉冲响应函数.实验搭建了一套非全息衍射投影系统,对投影过程中产生的像差和亮度不均匀进行矫正,获得了无相干噪音的高品质衍射图像,实现了投射比为0.87的无限景深的衍射投影.在相距大于800 mm的不同深度平面上同时获得了清晰的投影图像,从而验证了方法的可行性.该投影方法和系统在球幕投影、任意曲面屏幕投影和增强现实投影等领域具有潜在的应用. 相似文献
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Takayuki Kokawa Hideto Saigusa Iichirou Aino Chiharu Matsuoka Tsuyoshi Nakamura Kumiko Tanuma Kazuo Yamashita Seiji Niimi 《Journal of voice》2006,20(3):414-422
SUMMARY: This study identified that physiologically the superior pharyngeal constrictor muscle at the level of the base of the tongue contributes to retrusive movement of the tongue with constriction of the mid-pharyngeal cavity and possesses unique properties in terms of motor speech control along with the genioglossus muscle. From a kinematic study involving trans-nasal fiberscopy and lateral X-ray fluorography, retrusive movement of the tongue was highly correlated with constrictive movement of the mid-pharyngeal cavity. An electromyographic study revealed that the superior pharyngeal constrictor muscle at the level of the base of the tongue contributes to retrusive movement of the tongue and that the genioglossus muscle contributes to protrusive movement. We also noted that this relationship between the activities of these two muscles were in response to postural changes during vowel productions without changes in the acoustic features. These findings suggest that these two muscles act not only antagonistically to produce retrusive and protrusive movement of the tongue, but also they complement each other to conserve the shape of the vocal tract for speech production. The functional relationship between these two muscles could contribute the consecutive movement of human speech production under various conditions and might be useful when applying rehabilitation approaches for the patients with neurological speech and swallowing disorders. 相似文献
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I. Schmelzer 《Foundations of Physics》2011,41(2):159-177
Pure interpretations of quantum theory, which throw away the classical part of the Copenhagen interpretation without adding new structure to its quantum part, are not viable. This is a consequence of a non-uniqueness result for the canonical operators. 相似文献