共查询到20条相似文献，搜索用时 62 毫秒
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王进贺 《新疆教育学院学报》1995,(4)
本文绘出了一类抛物型方程解的能量模估计，并进一步讨论了解的唯一性和稳定性，推进了某些文献的重要结果。关键词：抛物型方程能量模定解问题唯一性稳定性在讨论波动方程解的唯一性与稳定性时，能量模估计的方法是非常有效的工具，它同样适用于抛物型方程，文献[1]，[2]将这个方法引入到一维热传导方程解的性态的讨论中，本文对一类较一般的抛物型方程给出解的能量模估计，并讨论解的唯一性与稳定性。考虑如下抛物型方程的定解问题其中n是R”空间具有光滑边界的有界域，闭表示n的边界，壬（X，t），叩（X）为适当光滑的函数定理一：（能… 相似文献
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本文讨论了平板间层流Orr-Sommefeld流的稳定性，提出了该问题的稳定性定理，并给出证明。 相似文献
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研究了可控随机非完整Hamilton系统的矩稳定性的条件，通过恰当地选择控制参量u，从而使系统满足稳定性条件，首先，给出可控随机非完整Hamilton系统的运动方程和平衡方程，然后，讨论了可控随机非完整Hamilton系统的均值稳定性的条件。 相似文献
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再谈轨道的稳定性 总被引：1，自引：0，他引：1
冯胜奇 《韩山师范学院学报》2005,26(3):17-19
讨论了质点运动轨道的稳定性问题，并给出了轨道稳定性的几个简明而又实用的判据，然后分析了有心力场中质点轨道的稳定性问题． 相似文献
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本文主要针对常微分方程组类型的生态数学模型，应用常微分方程稳定性理论作出稳定性分析，主要使用李雅普诺夫第二方法讨论多种群落的全局稳定性。 相似文献
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通过理论研究和数值计算，详细分析了大跨径钢管混凝土双肋拱桥的侧倾稳定性和地震响应。首先，根据双肋拱桥结构在竖向均布荷栽作用下的侧倾稳定临界力的近似解析解，讨论了横撑设置、横撑刚度等因素对稳定性的影响。其次，基于多点激振理论和拟静力位移概念，介绍了拱桥结构的动力特点和地震动作用下的响应，并讨论了行波效应的影响。分析表明，地震行波作用对大跨度拱桥影响很大，横撑设置对稳定性敏感。 相似文献
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本研究了种群按照广义Logistic生长，讨论其平衡点的稳定性及在常数捕获率和线性捕获率的情况下投入产出关系，进而讨论自反馈模型。 相似文献
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利用微分方程定性理论，研究了一类基于家庭检测和追踪的最小流行病模型的奇异流形的存在性和稳定性，给出了奇异流形存在性和稳定性的充要条件，讨论了在奇异流形附近发生的非参数跨临界分岔，同时利用Matlab进行数值模拟，验证了基本再生数大于或小于1时流形的稳定性. 相似文献
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结合力学系统平衡的三种形式，讨论判别力学系统平衡稳定性的静力学准则、动力学准则和能量准则。给出了离散系统平衡稳定性的能量判别准则的具体形式。 相似文献
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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 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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Rachel Zupek 《海外英语》2007,(11):40-41
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了 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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YANGShiguo 《重庆大学学报(英文版)》2004,3(1):86-88
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex. 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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GUO Bao-feng Xiao Da-wei 《重庆大学学报(英文版)》2005,4(3):129-133
Using virtual reality for interactive design gives a designer an intuitive vision of a design and allows the designer to achieve a viable, optimal solution in a timely manner. The article discusses the process of making the Virtual Reality System of the Humble Administrator＇s Garden. Translating building data to the Virtual Reality Modeling Language （VRML） is by far unsatisfactory. This creates a challenge for computer designers to do optimization to meet requirements. Five different approaches to optimize models have been presented in this paper. The other methods are to optimize VRML and to reduce the file size. This is done by keeping polygon counts to a minimum and by applying such techniques as object culling and level-ofdetail switching. 相似文献