共查询到20条相似文献，搜索用时 62 毫秒
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RLC电路弹簧耦合系统的非线性振动 总被引：3，自引：2，他引：3
为研究RLC电路弹簧耦合系统的非线性振动,通过拉格朗日-麦克斯韦方程,建立了受到简谐激励作用具有平方非线性的RLC电路弹簧耦合系统的数学模型。应用非线性振动的多尺度法,得到一种内共振和一种双重共振的一次近似解,并进行数值分析。讨论了激励、调谐参数等对系统的影响。发现在内共振2ω≈21ω,双重共振2ω≈2ω1且Ω≈1ω两种情况下,系统具有丰富的动力学现象。 相似文献
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研究非线性地基上圆形薄板受简谐激励的非线性振动问题。按照弹性力学理论建立非线性地基上圆形薄板受简谐激励的动力学方程,利用Galerkin方法将其转化为非线性振动方程,该方程是马休型方程。应用非线性振动的多尺度法求得系统主参数共振的近似解,并进行数值计算。分析阻尼、地基系数、几何参数等对共振响应曲线的影响。 相似文献
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弹性地基上四边自由矩形大挠度薄板复杂运动研究 总被引：15，自引：1，他引：15
考虑具有粘滞阻尼的Winkler地基上四边自由受简谐激励的矩形板的偏微分方程组,找到了满足所有边界条件的近似挠度函数,利用Galerkin方法把偏微分方程表示的非线性动力学方程转化为用常微分方程表示的非线性动力学方程。应用多尺度法求得了系统的主共振解,并对主共振解的静态分岔方程进行了奇异性分析。应用Floquet理论和Melnikov方法分析了系统的全局特性。 相似文献
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建立了电机转子机电耦联的非线性数学模型 ,研究了由电磁力激发的参数振动非线性系统的响应曲线 ,揭示了各种电磁参数及机械参数对共振的影响 .结果表明 ,系统在电磁力作用下存在着 1/2亚谐共振的条件 ,电磁力对稳定区域有明显影响 ,且其线性项和非线性项均能激发参数共振 .同时建立了机电耦联问题的电机系统的稳定性条件 ,并得到了参数域中的稳态共振曲线和运动状态 ,所揭示的动力学现象为定性地控制电机的稳定运行状态提供了理论依据 相似文献
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加速度共振现象及其特征 总被引：2，自引：0，他引：2
孟振庭 《渭南师范学院学报》2001,16(6):88-91
在受迫振动中，振动加速度达到最大值时的共振现象，称为“加速度共振”，其共振条件为Ω=ω^2/√ω^2-2β^2,振幅比通常的位移共振的振幅小，初位相比通常的位移共振的初位相大，其共振特征明显，物理意义明确。 相似文献
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三次原根ω的性质及应用□会宁职专李克靖一、ω的主要性质若虚数－１＋３ｉ２定义为ω,则ω有以下重要性质：１ω３＝１,ω２＋ω＋１＝０．２ω为１的三次原根,且ω３ｎ＝１,ω３ｎ＋１＝ω,ω２ｎ＋２＝ω２,（ｎ为整数）．３１,ω,ω２在复平面内的对应... 相似文献
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用多尺度方法对－土－平台系统进行了摄动分析，发现此系统存在多种组合共振现象，其固有振动频率与模型平台实测结果一致．在主参数共振条件下，文章讨论了在不同振动类型（自激，锁定，强迫）下的非线性动力学特性，这与现场观察到的冰激平台共振现象一致，本文还解释了冰激振动的机理，为海洋平台系统的非线性分析建立了一个合理的力学模型． 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
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Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献
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RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献
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唐芳 《读与写:教育教学刊》2008,5(6)
During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context. 相似文献