共查询到20条相似文献,搜索用时 31 毫秒
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论述了"第三教学"的基本内容,并结合我们10年来"第三教学"的实践及效果,讨论了"第三教学"的有关问题及其意义. 相似文献
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《物理通报》2010年第2期发表的《对第26届物理竞赛一道"角动量"题目的解读》一文(后称[1]文),对第26届物理竞赛一道"角动量"题目进行了详细的分析并对标准参考答案加以补充.此问题笔者有不同看法,特提出讨论,并希望得到同行 相似文献
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人教版九年级物理教材,第十四章"压强和浮力"第3节"大气压强",有关于大气压的测量"想想做做"的内容:"将蘸水的塑料挂钩的吸盘放在光滑水平板上,挤出里面的空气.用弹簧测力计钩着挂钩缓慢往上拉,直到吸盘脱离板面. 相似文献
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由人民教育出版社出版的普通高中新课程标准实验教科书《物理·必修2》(2010年4月第3版)具有比较新颖的理念,和以往的教材相比,它更加注重培养学生的科学素养,使物理更贴近生活.第五章"曲线运动"中第1节(第4页)以"红蜡块的运动"为实例,通过教师的演示实验让学生认真观察从而能 相似文献
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本刊2010年第5期第14页《用排列对比方法讲解相对论》一文,希望达到用时少、效果好的目标,这个愿望很好,只是其中有些提法值得商榷.(1)第14页左栏倒数第8行"真空中光速不变" 相似文献
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笔者最近有机会听了一些老师的初中物理课,在一些老师的“内能”概念教学实践中,笔者发现他们总是在想方设法运用各种教学手段强调如下两个教学要点: 相似文献
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一类不连续不可逆保面积映象可以展示类似耗散的行为,因此可称其为“类耗散系统”.在一种类耗散系统中观察到了椭圆周期轨道及其周围的椭圆岛与映象不连续边界碰撞而消失的现象.周期轨道消失后,经过一系列过渡椭圆周期轨道之后,系统的行为由一个混沌类吸引子主导.在混沌类吸引子刚刚出现时,混沌时间序列呈现层流相与湍流相的无规交替.这一切都与不连续耗散系统中发生的Ⅴ型阵发的相应性质十分相似,因此可称为“类Ⅴ型阵发”.然而,当混沌类吸引子刚刚出现时,仅可以找到最后一个过渡椭圆岛的“遗迹”,并不存在它的“鬼魂”,因此类Ⅴ型阵发不遵从Ⅴ型阵发的特征标度规律.反之,混沌类吸引子的鬼魂却存在于最后一个过渡椭圆周期轨道的类瞬态过程中,因此在类Ⅴ型阵发导致混沌运动的临界点之前,由此“类瞬态混沌奇异集”中逃逸的规律就成为标志这一种临界现象的标度律.这与Ⅴ型阵发又根本不同.
关键词:
类耗散性
类混沌吸引子
类Ⅴ型阵发 相似文献
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Nasuno S 《Chaos (Woodbury, N.Y.)》2003,13(3):1010-1013
Highly localized, dynamic particle-like excitations are observed in a dc-driven, quasi-two-dimensional gas-discharge system. These localized excitations undergo a transition from isolated to aggregated state as the discharge current is increased. Although they provide us a macroscopic analogue of microscopic atoms and molecules, they are quite distinct from the latter in the point that they exhibit a rich variety of complex dynamics. The fact that these localized excitations can show synchronous dynamics even in distant places, together with recent theoretical studies, indicates that a global coupling plays an important role on the dynamics of such localized excitations. 相似文献
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A newly discovered group of alloys, called Gum Metals, approaches ideal strength in bulk form, exhibits significant plastic deformation prior to failure, and shows no indications of conventional-dislocation activity. Two conditions must be met for a material to exhibit this "ideal" behavior: (1) the stress required to trigger conventional-dislocation plasticity in the material must exceed its ideal strength, and (2) the material must be intrinsically ductile when stressed to ideal strength. Gum Metals satisfy both criteria, explaining their remarkable mechanical properties. 相似文献
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Shvartsburg AA Hudgins RR Dugourd P Gutierrez R Frauenheim T Jarrold MF 《Physical review letters》2000,84(11):2421-2424
The hypothesis that fullerenes grow in a carbon plasma by the addition of C2 units (the "fullerene road") has been widely acclaimed as the most plausible mechanism for formation of larger fullerenes including C60 and C70. Calculations suggest that the association of C2 with fullerenes proceeds through two classes of intermediates, "sticks" and "handles." Here we report the observation of these species using high-resolution ion-mobility measurements for C(n) cations generated by laser vaporization of graphite and laser desorption of C60. Sticks with up to eight-atom chains have also been found. 相似文献