求轨迹方程时要注意“去伪”与“补漏”

我们知道，求曲线方程可分为两类：（1）已知曲线类型，求曲线方程；（2）不知曲线类型，求曲线方程．对于第（1）类，通常可用待定系数法解决．对于第（2）类，需要在适当的直角坐标系中，将动点满足的几何关系转化为动点坐标的方程后，经化简得出轨迹方程．教学中发现，学生在解决第（2）类问题时，常常在求出方程后就以为大功告成，不再去考虑方程的曲线是否与已知轨迹相符．根据曲线与方程的关系，只有当所求方程的曲线与已知轨迹恰好一致，即方程的曲线上的点恰好与已知轨迹上的点一样多，才能称所求方程是已知轨迹的方程，如若不然，…     

一般动态轴对称黑洞的热辐射

本文给出了一般动态轴对称黑洞热辐射温度和视界面方程的普遍关系，对于具体的动态轴对称黑洞，只须把已知度规代入普遍关系式，即可确定出黑洞的辐射温度和视界面方程，所得结论能回到已知的结果．     

共渐近线的双曲线系方程在解题中的运用

共渐近线的双曲线系方程在解题中的运用浙江省黄岩市金清中学解启法［基本概念］尚不能完全确定其双曲线方程，而只能确定其双曲线系方程为［基本方法］已知双曲线的渐过其他已知条件（如双曲线过某已知点，或已知焦距或实轴或虚轴的长，或已知两准线间距离，或已知焦点坐...     

时滞Logistic方程与不等式解的振动性与渐近性

本文研究了时滞Ｌｏｇｉｓｔｉｃ方程与不等式关于方程平衡占的振动与非振动解的渐近性问题，得到了一些新的充分条件。本文的结果推广并改进了若干已知的定理。     

随机发展方程小扰动的容度大偏差原理

本文证明了随机发展方程小扰动的容度大偏差原理，所获结果改进和加强已知的结果     

具有连续变量的差分方程的振动性

本文建立了具有连续交量差分方程的振动性判据，其结果改进了文献中的某些已知结果．     

含多重积分的Volterra型积分方程与不等式

本文考虑一定有序局部紧空间上含多重积分的Ｖｏｌｔｅｒｒａ型积分方程，给出了此类方程可解的充分条件，建立了相应的积分不等式．本文结果包含许多已知结论作为特殊情况．     

计算机自动优选回归曲线方程

计算机自动优选回归曲线方程，乃是凭借笔者开发研制的计算机专用软件，在系统内给出的２０个曲线方程中，由计算机自动快速选出一个与已知二维数组散点图拟合得最佳的曲线方程，作为二维数组的回归曲线方程．     

非线性非单调算子方程的解

该文研究了一类非线性，非单调算子方程x＝A（x，x）的解的存在性及唯一性，推广并改进了若干已知结果．     

二元回归数学模型系统

二元回归数学模型系统，原理是二元回归分析．其主要方法是把曲面方程转化成平面方程，利用笔者研制的专用程序来自动优选回归曲面与三维数组散点间拟合得最佳的一个曲面方程，作为已知三维数组的数学模型     

关于伽辽金方法收敛性的判别准则

<正> 伽辽金方法的重要性已为工程数学界所公认.有关它的收敛性的讨论,亦有大量文献与专著.但从算子方程的角度来看,所加的条件还很苛刻.本文则在较一般的条件下给出了伽辽金方法收敛性的一系列判别准则.我们相信,这些结果对于实际应用将是有益的.     

Hilbert C~*-模上可共轭算子的并联和

本文研究了Hilbert C~*-模上可共轭算子的并联和,推广了矩阵和Hilbert空间上有界线性算子的一些相关结果.通过举例说明:存在一个Hilbert C~*-模H,以及H上的两个可共轭的正算子A和B,使得算子方程A~(1/2)=(A+B)~(1/2)X, X∈■(H)无解,其中■(H)为H上的可共轭算子全体.     

Hamiltonians with two degrees of freedom admitting a singlevalued general solution

Following the basic principles stated by Painleve, we first revisit the process of selecting the admissible time-independent Hamiltonians H=(p12 + p22)/2 + V(q1,q2) whose some integer power qjnj (t) of the general solution is a singlevalued function of the complex time t. In addition to the well known rational potentials V of Henon-Heiles, this selects possible cases with a trigonometric dependence of V on qj. Then, by establishing the relevant confluences, we restrict the question of the explicit integration of the seven (three "cubic" plus four "quartic") rational Henon-Heiles cases to the quartic cases. Finally, we perform the explicit integration of the quartic cases, thus proving that the seven rational cases have a meromorphic general solution explicitly given by a genus two hyperelliptic function.     

Existence of almost periodic solutions for forced perturbed systems with piecewise constant argument

Certain almost periodic forced perturbed systems with piecewise argument are considered in this paper. By using the contraction mapping principle and some new analysis technique, some sufficient conditions are obtained for the existence and uniqueness of almost periodic solution of these systems. Furthermore, we study the harmonic and subharmonic solutions of these systems. The obtained results generalize the previous known results such as [A.M. Fink, Almost Periodic Differential Equation, Lecture Notes in Math., vol. 377, Springer-Verlag, Berlin, 1974; C.Y. He, Almost Periodic Differential Equations, Higher Education Press, Beijing, 1992 (in Chinese); Z.S. Lin, The existence of almost periodic solution of linear system, Acta Math. Sinica 22 (5) (1979) 515-528 (in Chinese); C.Y. He, Existence of almost periodic solutions of perturbation systems, Ann. Differential Equations 9 (2) (1992) 173-181; Y.H. Xia, M. Lin, J. Cao, The existence of almost periodic solutions of certain perturbation system, J. Math. Anal. Appl. 310 (1) (2005) 81-96]. Finally, a tangible example and its numeric simulations show the feasibility of our results, the comparison between non-perturbed system and perturbed system, the relation between systems with and without piecewise argument.     

二部图形式的Erd\H{O}s-S\'{o}s猜想

二部图形式的Erd\H{O}s-S\''{o}s猜想     

General non local boundary value problem for second order elliptic equation

In this paper we study a class of second order coefficient operators differential equation with general (possibly non local) boundary conditions. We obtain new results extending those given in a previous paper 1 . Existence, uniqueness and optimal regularity of the strict solution are proved in UMD spaces, using the well‐known Dore–Venni theorem.     

(2+1)维浅水波方程的新精确解

对(2+1)维浅水波方程的现有解进行了推广.应用CK方法对方程进行求解,得到方程的Backlund变换公式,将已知解代入公式,求得一些新的精确解,从而推广了浅水渡方程的解.     

Banach空间内一类含松弛-(H,η)-调算子的广义混合拟似变分包含组

在Banach空间内,引入和研究了一类新的含松弛-(H,η)-单调算子的广义混合拟似变分包含组.利用松弛-(H,η)-单调算子的豫解算子技巧,给出了求这类广义混合拟似变分包含组近似解的一个新逼近算法,并证明了由这个新算法生成的迭代序列强收敛于该变分包含组的精确解.文章结果改进与推广了近期文献中的相应结果.     

偶交叉双积Hopf代数B RH的构造

本文给出了Doi Y.构造的偶交叉积B H的代数结构与Reshetikhim～N.构造的双代数BRH的余代数结构在张量空间B H上构成双代数(记为BRH)的充要条件,利用此结论具体构造了一个有趣的例子H4 KZ2,证明了当B,H均为Hopf.代数时BRH也为Hopf代数,最后给出这类双代数的映射刻划.     

Parallel Schur complement method for large-scale systems on distributed memory computers

The Schur complement method, also known as substructuring technique, was widely used in structural mechanics to solve large-scale systems with limited memory computers for more than three decades [J.S. Przemieniecki, AIAA J. 1 (1963) 138]. Currently, due to developments in computer technology, the available on-board memory has increased considerably. Despite the existence of these high-memory systems, the Schur complement method still finds its applications in structural mechanics through parallel computing. When developing a computer program, the Schur method has a significant book-keeping load in comparison to other parallel algorithms used, e.g., Schwarz alternating domain decomposition method [H.A. Schwarz, Gesammelte Mathematiche Abhandlungen, vol. 2, Springer, Berlin, 1890, p. 133]. This results in memory usage. Although parallel systems are used, global coefficient matrices require a large amount of memory. Therefore, significant memory is reserved for the solution of large-scale systems. In this paper, we present an efficient algorithm for the assemblage and solution of interface equations which facilitates the solution of large-scale systems via the Schur complement method on multiple instruction multiple data (MIMD) distributed memory architectures. In this method, we assemble the subdomain and interface coefficient matrices in such a manner that the memory requirements decrease significantly, resulting in the solution of large-scale systems with reasonable memory usage. The computer program is tested on distributed memory architectures with UNIX, WINDOWS NT, and LINUX operating systems.