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谈谈“圆锥及其表面求点”的教学设计
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作者 刘秋月 《职教论坛》 2003年第4期42-42,共1页
"圆锥及其表面求点"采用模型和计算机多媒体网络教学比较好,本人结合教学实践谈点体会. 首先,设计一个主菜单:一、圆锥表面的组成:二、锥形零件及其制造过程;三、圆锥面的形成;四、圆锥的三视图;五、圆锥表面求点;六、总结;... "圆锥及其表面求点"采用模型和计算机多媒体网络教学比较好,本人结合教学实践谈点体会. 首先,设计一个主菜单:一、圆锥表面的组成:二、锥形零件及其制造过程;三、圆锥面的形成;四、圆锥的三视图;五、圆锥表面求点;六、总结;七、作业.然后依次展开教学. 展开更多
关键词 圆锥及其表面求 教学设计 技工学校 计算机辅助教学 数学
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圆锥曲线一个性质的完善
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作者 叶挺彪 《中学数学月刊》 1998年第1期28-29,共2页
文[1]给出类似于“焦点与准线的对应关系”的抛物线的性质,文[2]把其扩张到圆锥曲线上,以三个命题的形式出现,其中命题2针对双曲线的情形还欠完善,本文将作点补充,并说明补充后是完备的。文[2]的命题2是:设有双曲线(x^2/a^2)-(y^2/b^2)=... 文[1]给出类似于“焦点与准线的对应关系”的抛物线的性质,文[2]把其扩张到圆锥曲线上,以三个命题的形式出现,其中命题2针对双曲线的情形还欠完善,本文将作点补充,并说明补充后是完备的。文[2]的命题2是:设有双曲线(x^2/a^2)-(y^2/b^2)=1(a】0,b】0),M(m,0)为x轴上除原点和顶点外的任一点,过M点引一条直线与双曲线相交于A,B两点,则这两点与x轴上的另一点N((a^2/m),0)的连线与x轴成等角。 展开更多
关键词 圆锥曲线 双曲线方程 中学数学 线相交 虚轴 圆锥点 必要性 抛物 对应关系 对称
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POSITIVE PERIODIC SOLUTIONS OF FIRST AND SECOND ORDER ORDINARY DIFFERENTIAL EQUATIONS 被引量:17
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作者 LIYONGXIANG 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2004年第3期413-420,共8页
In this paper the existence results of positive ω-periodic solutions are obtained forsecond order ordinary differential equation-u'(t)=f(t,u(t)) (t∈R), and also for firstorder ordinary differential equation u... In this paper the existence results of positive ω-periodic solutions are obtained forsecond order ordinary differential equation-u'(t)=f(t,u(t)) (t∈R), and also for firstorder ordinary differential equation u'(f)=f(t,u(t)) (t∈R), where f: R×R^+→Ris a continuous function which is ω-periodic in t. The discussion is based on the fixedpoint index theory in cones. 展开更多
关键词 Positive periodic solution CONE Fixed point index
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Quasi-Conical Quantum Dot: Electron States and Quantum Transitions
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作者 Eduard M.Kazaryan Lyudvig S.Petrosyan +1 位作者 Vanik A.Shahnazarya Hayk A.Sarkisyan 《Communications in Theoretical Physics》 SCIE CAS CSCD 2015年第2期255-260,共6页
The exactly solvable model of quasi-conical quantum dot, having a form of spherical sector, is proposed. Due to the specific symmetry of the problem the separation of variables in spherical coordinates is possible in ... The exactly solvable model of quasi-conical quantum dot, having a form of spherical sector, is proposed. Due to the specific symmetry of the problem the separation of variables in spherical coordinates is possible in the one- electron Sehrodinger equation. Analytical expressions for wave function and energy spectrum are obtained. It is shown that at small values of the stretch angle of spherical sector the problem is reduced to the conical QD problem. The comparison with previously performed works shows good agreement of results. As an application of the obtained results, the quantum transitions in the system are considered. 展开更多
关键词 conical quantum dot electron states quantum transitions
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