排序方式: 共有90条查询结果,搜索用时 15 毫秒
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Wu Shaoping 《数学年刊B辑(英文版)》1996,17(2):245-256
The existence of at least two homoclinic orbits for Lagrangian system (LS) is proved, wherethe Lagrangian L(t,x,y) =1/2∑aij(x)yiyj-V(t, x), in which the potential V(t,x) is globallysurperquadratic in x and T-periodic in t. The Concentration-Compactness Lemma and Mini-max argument are used to prove the existences. 相似文献
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Yang Li Zhang Qingling Liu Guoyi 《Annals of Differential Equations》2005,21(3):497-502
We discuss the delay dependent robust dissipative problem for a class of time-delay systems with nonlinear perturbations. And the sufficient conditions for the delay dependent robust dissipation and quadratic stability are given by the linear matrix inequalities (LMIs), then the time-delay bound and the delay dependent robust dissipative state feedback controller are presented. 相似文献
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判别式是二次函数、二次方程和二次不等式中经常涉及到的一个基本量,其基本结构⊿=b2-4ac,在解函数、方程、不等式等问题时,有时可从形似到神似,联想构造二次函数,妙用判别式,现举例说明.…… 相似文献
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运算卡壳是学生解答圆锥曲线综合题的常见障碍,本文以一道椭圆中定点证明问题的教学为例介绍如何帮助学生克服这类障碍,在教学中,教师要善于发现学生的运算障碍节点,顺应学生的思维发展,通过巧设问题合理引导学生思维进阶,理解运算对象,探究运算思路,选择运算方法,充分发展学生的数学运算素养. 相似文献
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Aleksander GRYTCZUK Jarostaw GRYTCZUK 《数学学报(英文版)》2005,21(5):1107-1112
We investigate arithmetic properties of certain subsets of square-free positive integers and obtain in this way some results concerning the class number h(d) of the real quadratic field Q(√d). In particular, we give a new proof of the result of Hasse, asserting that in this case h(d) = 1 is possible only if d is of the form p, 2q or qr. where p.q. r are primes and q≡r≡3(mod 4). 相似文献