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1.
对于求解常系数线性非齐次方程的特解,一般的方法是比较系数法,或者是给出了初始条件后,用拉普拉斯变换法,虽然这些方法比较简便,也很适用,但限制太多,有一定的局限性,本文对微分方程的算子解法作了详细的介绍,以及它的原理及应用,侧重的综合介绍一系列算子方法及重要结果与公式。 相似文献
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目前对于分数阶微分方程的解析解的求法就较为单一,主要采用拉普拉斯变换及其逆变换来求.对于Caputo型分数阶导数积分下限a=-∞时,指数函数f（t）=en和常数函数f（t）=C的分数阶导数与整数阶导数相类似的.部分分数阶常微分方程也可以用特征根的方法求得通解,但分数阶常微分方程与一般微分方程的通解中相互独立的任意常数个数却有很多不同. 相似文献
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This essay performs a rhetorical criticism of neo-classical economics, with particular attention to its methodological influence on a number of faulty mathematical models that lay at the epicenter of the 2008 financial crisis. Going beyond Goodnight and Green's mimetic conception of economic rhetoric, which positions rhetoric as a site of mediation between symbolic and material spirals, we argue that the rhetoric of neo-classicism is best understood as an “apparatus” that attempts to suture two ontologically incommensurable conceptions of time that we term intensive and extensive. We further argue that the hinge of this rhetorical apparatus centers on a kairotic tactic of arbitrage, which theoretically posits, at the same time that it negates, ontological market failure. We end by exploring rhetorical alternatives to neo-classical economics that take the internally contradictory structure of arbitrage to its emergent conclusions. 相似文献
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ＩＮＴＲＯＤＵＣＴＩＯＮＩｔｉｓｉｍｐｏｒｔａｎｔｔｏｆｏｒｅｃａｓｔａｎｄｃａｌｃｕｌａｔｅｔｈｅｒｏｌｅｏｆｃｏｎｓｏｌｉｄａｔｉｏｎｉｎｓｔｒｅｎｇｔｈｅｎｉｎｇｓｏｆｔｓｏｉｌｇｒｏｕｎｄ .Ｆｏｒｃｏｎｖｅｎｉｅｎｔｕｓｅｉｎｅｎｇｉｎｅｅｒｉｎｇ ,ｔｈｅｍｏｄｅｌｏｆｃｏｎｓｏｌｉｄａｔｉｏｎｗａｓｒｅｄｕｃｅｄｔｏａｏｎｅ ｄｉ ｍｅｎｓｉｏｎａｌｐｒｏｂｌｅｍｉｎｓｐａｔｉａｌｄｏｍａｉｎ .ＳｉｎｃｅＴｅｒｚａｇｈｉｅｓｔａｂｌｉｓｈｅｄｏｎｅ ｄｉｍｅｎｓｉｏｎａｌｌｉｎｅａｒｃｏ… 相似文献
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利用变分法研究非线性奇异微分方程(g(t)|u′(t)|p-2u′(t))′-|u(t)|p-2u(t)=λF(t,u(t)),a.e.t∈[0,T]u(0)-u(T)=gq-1(0)u′(0)-gq-1(T)u′(T)=0(P)周期解的存在性和多重性问题,其中T>0,λ>0,g∈L∞(0,T;R+),ess.infg>0,p2,1p+1q=1,F:[0,T]×RN→R满足下面的假设:(A)对任意的u∈RN,F(t,u)关于t可测;对几乎所有的t∈[0,T],F(t,u)关于u连续可微.并且存在a∈C(R+,R+),b∈L1(0,T;R+),使得对一切的u∈RN,几乎所有的t∈[0,T],有|F(t,u)|a(|u|)b(t),|F(t,u)|a(|u|)b(t). 相似文献
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This paper considers the synchronization of solutions for lattices of the coupled non-autonomous Chen system. By using the
Lyapunov function, we show that when the second coupled operator is negative definite self-adjoint and its coefficient is
suitable large, the Chen coupled lattice system is bounded dissipative (In particular, the solutions for lattices of the coupled
autonomous Chen system converge to zero as t → ∞). The synchronization between any two solutions of the coupled Chen system can be slaved only by coefficients in the
x- or y-component for the suitably large second coupled coefficient. Finally, some numerical simulations are given.
Project supported by the National Natural Science Foundation of China (Grant No.10771139) 相似文献
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According to most theories, in a simple contingency learning situation, excitatory learning occurs when the probability of the unconditioned stimulus in the presence of the conditioned stimulus (p1) is higher than the probability of the unconditioned stimulus in the absence of the conditioned stimulus (p2). In Rescorla and Wagner??s (1972) model, this prediction varies, depending on the parameters used. In the following experiments, we evaluated whether the difference between p1 and p2 that is required to produce excitatory conditioning is the same, independent of the specific value of p1, or whether this difference varies proportionally to p1??s value. To do so, an appetitive procedure of Pavlovian conditioning with rats was used. In four experiments, we compared different levels of contingency (low, medium and high) and found that the difference between p1 and p2 that is required to produce excitatory conditioning increases when the value of p1 is higher. The possibility of analyzing contingency learning as a discrimination between p1 and p2 is also discussed. 相似文献
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Mansoor Niaz 《科学教学研究杂志》1991,28(1):19-40
Most Piagetian formal operational reasoning tasks show horizontal decalage; that is, subjects pass certain tasks and fail others that have the same logical structure. The study reported here analyzes the importance of individual difference variables, as postulated by the neo-Piagetian theory of Pascual-Leone, in explaining subject performance in formal reasoning. A sample of 72 freshman students were administered a test of formal reasoning having 20 items of different types of reasoning, and the tests of the individual difference variables. Results obtained from multiple regression analyses show that Pascual-Leone's structural M-capacity (Ms) is the most consistent predictor of success in the different formal reasoning tasks, followed by Witkin's cognitive style, and to a much lesser degree Raven's progressive matrices, and Pascual-Leone's functional M-capacity (Mf). It was found that in the total score on the 20 items of formal reasoning, Ms accounted for 23.3% of the variance (R = 0.483, F = 6.39, p = 0.014) and Witkin's Group Embedded Figures Test, increased the multiple R significantly (F = 7.77, p = 0.007) and accounted for 7.6% of the variance. Mf and the Raven test did not make a significant contribution to the regression equation. Correlation coefficients among most of the items having the same reasoning pattern but different content are generally low but statistically significant (p < 0.01). Intercorrelations among items having the same formal reasoning pattern and content are fairly high (p < 0.001). These results emphasize the importance of individual difference variables: information-processing capacity (Pascual-Leone) and oversensitivity to potentially misleading information (Witkin). It is suggested that in order to understand student performance in formal reasoning tasks, we should expect horizontal decalages as a rule and not the exception, as Piaget had postulated. Educational implications are drawn. 相似文献
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Young adolescent psychological need profiles: Associations with classroom achievement and well‐being
Stephen R. Earl Ian M. Taylor Carla Meijen Louis Passfield 《Psychology in the schools》2019,56(6):1004-1022
Drawing on self‐determination theory, a person‐centered methodology was adopted to identify distinct pupil profiles based on their psychological need satisfaction. A sample of 586 pupils (387 male, 199 female; mean age = 12.6, range 11–15 years old) from three secondary schools reported their psychological need satisfaction, and well‐ and ill‐being, with teachers rating pupil achievement. Hierarchical cluster analysis revealed five distinct profiles. Four profiles indicated synergy existed between the three needs, showing similar in‐group levels of satisfaction across the needs but in varying amounts. Univariate and multivariate analyses, controlling for school and taught subject, revealed the satisfied group displayed the highest classroom performance (F4,540 = 7.03; p < 0.001; ηp2 = 0.05), well‐being (F8,1,136 = 45.63; p < 0.001; Wilk's Λ = 0.57; ηp2 = 0.24) and lowest ill‐being (F8,1,134 = 23.39; p < 0.001; Wilk's Λ = 0.74, ηp2 = 0.14), whereas the dissatisfied group displayed the most adverse outcomes. The findings illustrate that the three psychological needs may operate interdependently and should be considered in combination rather than in isolation. The research offers practical insights into why pupils may function differently in classrooms and could inform targeted initiatives towards pupils with psychological need satisfaction deficits. 相似文献
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Abstract This paper reports a simple experiment which explores young children's written representation of number. Previous research (e.g. Hughes, 1983; Sinclair, Siegrist & Sinclair, 1982) has shown that several factors may influence the extent to which children will spontaneously deploy their knowledge of numerals to represent numerosity, but the available evidence is insufficient to provide a clear account of the relative weight of these factors. The present experiment involved presenting five to six year‐old children with arrays of simple objects and manipulating the wording of the instructions. The results showed that the use of the term ‘how many’ led the vast majority of the children to show numerosity by using materials. In contrast, when asked to represent ‘what’ they could see, most children concerned themselves with depicting the nature of the objects in the array by drawing or writing. These findings suggest that the linguistic context of the task is important in determining the children's representational strategies. Furthermore, it is argued that children's understanding of number and their ability to use numerals is quite separable from their knowledge of when it is appropriate to deploy these skills. 相似文献
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吕小芬 《湖州师范学院学报》2007,29(1):16-20
给定单位球B上的解析函数g,刻划了从加权Bergman空间到Bloch型空间及小Bloch型空间的广义Cesàro算子Lg的有界性和紧性特征.此处Lg定义为Lgf(z) =∫10g(tz)f(tz)dt/t. 相似文献
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徐千里 《湖南城市学院学报》1999,(5)
考察自由项为cose~x或sine~x的n阶常系数非齐线性方程,给出了求其特解的两种简单有效的方法：（1）Lagrange参数变易法和函数矩阵的初等行变换相结合的方法;（2）特榜公式． 相似文献
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YANG Qi-xiang 《浙江大学学报(A卷英文版)》2002,3(1)
This paper deals with the establishment of T(1) theorem on Hardy space H1 under condition of weak regularity. An operator or a function is identified on the basis of their wavelet coefficients which are regrouped on some blocks. The actions of each block operator (pseudo-annular operator) on each block function (atom) are exactly analyzed to establish T(1) theorem on Hardy space. 相似文献
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本文介绍了研究振动方程时的几种分析方法,并讨论了方程解的物理意义。自然界中最基本的振动是简谐振动,讨论简谐振动是研究复杂振动现象的基础,对其研究和分析方法很多,本文介绍几种求解振动方程的几种分析方法：1.常系数线性微分方程的一般求解法;2.拉普拉斯逆变换法;3.简谐振动的矩阵求解法,并讨论了方程解的物理意义。 相似文献
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Margarita Holmberg 《European Journal of Engineering Education》2017,42(4):413-428
The Laplace transform is an important tool in many branches of engineering, for example, electric and control engineering, but is also regarded as a difficult topic for students to master. We have interviewed 22 university teachers from five universities in three countries (Mexico, Spain and Sweden) about their views on relationships among mathematics, physics and technology/application aspects in the process of learning the Laplace transform in engineering education. Strikingly, the teachers held a spectrum of qualitatively differing views, ranging from seeing virtually no connection (e.g. some thought the Laplace transform has no relevance in engineering), through to regarding the aspects as intimately, almost inseparably linked. The lack of awareness of the widely differing views among teachers might lead to a lack of constructive alignment among different courses that is detrimental to the quality of engineering education. 相似文献
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杨定恭 《常熟理工学院学报》2009,23(2):1-7
设∑p（p是正整数）表示有孔单位开圆盘内型为f（z）=z^-p＋a1-pz^1-p＋…的解析函数类,利用广义超几何函数定义的线性算子,引进∑p的子类Mp^l,m（α1,λ,h）,研究了其包含关系与卷积性质． 相似文献