广义Linard方程解的振动性

本文研究广义Ｌｅｎａｒｄ方程解的振动性，在方程具有一个奇点与多个奇点的情形下，给出了使它的所有解振动的一系列充要条件，推广了文［２］，［４］的结果，改进了［５］的结果．     

广义Lienard方程解的振动性

本文研究了广义Ｌｉｅｎａｒｄ方程解的振动性，在方程具有一个奇点与多个奇点的情形下，给出了使它的所有解振动的一系列充要条件，推广了文［２］，［４］的结果，改进了［５］的结果。     

一类二阶时滞微分方程的振动性判据

本文从不同的角度研究一类二阶时滞微分方程的振动性，得到了一切解振动性的充分条件。改善了文［１］、［２］的工作．     

一类具偏差变元系统的振动性

在本文中，我们研究了具偏差变元系统Ｘ’（ｔ）＝ｐ（ｔ）Φ（ｘ（ｔ）ｙ（ｔ），ｙ’（ｔ）＝－ｆ（ｔ，ｘ（ｇ（ｔ））的解的振动性，所得结果推广了［１］［２］的有关结果，并与文献［３］［４］的结果互不包含。     

一类中立型微分方程的比较定理及应用

考虑中立型微分方程［ｘ（ｔ）－ｘ（ｔ－τ）］（ｎ）＋Ｑ（ｔ）ｘ（ｔ－σ）＝０，ｔｔ０，其中ｎ１为奇数，τ∈（０，∞），σ∈Ｒ＋＝［０，∞），Ｑ∈Ｃ（［ｔ０，∞），Ｒ＋）．本文获得了此方程存在最终正解以及所有解振动的新的比较定理．并据此获得了所有解振动的“ｓｈａｒｐ″条件以及存在最终正解的一般性结果，改进了文［４］的主要结果．     

中立型时滞Logistic方程有界正解的振动性与非振动性

本文研究中立型时滞Logistic方程的振动性与非振动性问题．所得结果改进了文［1］中的相关结论．     

具有振动容纳量的单种群模型

考虑当环境容纳量是振动时单种群增长模型解的渐近性，所得结果推广了文［５］中给出的结果。     

具有分段常数变元的时滞微分方程解的振动性(英文)

我们获得了带有分段常数变元的时滞微分方程ｘ′（ｔ）＋ａ（ｔ）ｘ（ｔ）＋∑ｍｉ＝１ｂｉ（ｔ）ｘ（［ｔ－ｉ］）＝０，ｔ≥０所有解振动的新的充分条件，这里［·］定义为最大整数函数．我们的结果改进了文献中的某些已知结果．     

中止规则的平均延迟时间及其应用

本文以平均延迟时间为度量，对适用于连续抽样方案的四种中止规则，即规则［Ｓ］，［Ｒ］，［Ｎ，ｃ］及［Ｒ，ｄ］的中止“速度”进行了比较。结果表明：［Ｒ］优于［Ｓ］，而［Ｎ，ｃ］与［Ｒ，ｄ］均优于［Ｒ］。这些结论及方法可被用来适当地选择中止规则，以提高连续型生产的质量控制水平     

含分段常数变元的中立型时滞微分方程的振动定理

含分段常数变元的中立型时滞微分方程的振动定理林诗仲俞元洪（海南师范学院，海口５７１１５８）（中国科学院应用数学研究所，北京１０００８０）１引言含分段常数变元的微分方程的研究是从文［１］和［２］开始，这类方程既具有连续动力系统的结构，又具有离散变元的差...     

Poly-Locality in Quantum Computing

A polynomial depth quantum circuit affects, by definition, a poly-local unitary transformation of a tensor product state space. It is a reasonable belief [Fe], [L], [FKW] that, at a fine scale, these are precisely the transformations which will be available from physics to solve computational problems. The poly-locality of a discrete Fourier transform on cyclic groups is at the heart of Shor's factoring algorithm. We describe a class of poly-local transformations, which include the discrete orthogonal wavelet transforms, in the hope that these may be helpful in constructing new quantum algorithms. We also observe that even a rather mild violation of poly-locality leads to a model without one-way functions, giving further evidence that poly-locality is an essential concept. March 1, 2000. Final version received: October 23, 2001.     

Construction of Continuous Functions with Prescribed Local Regularity

In this paper we investigate from both a theoretical and a practical point of view the following problem: Let s be a function from [0;1] to [0;1] . Under which conditions does there exist a continuous function f from [0;1] to R such that the regularity of f at x , measured in terms of H?lder exponent, is exactly s(x) , for all x ∈ [0;1] ? We obtain a necessary and sufficient condition on s and give three constructions of the associated function f . We also examine some extensions regarding, for instance, the box or Tricot dimension or the multifractal spectrum. Finally, we present a result on the ``size' of the set of functions with prescribed local regularity. November 30, 1995. Date revised: September 30, 1996.     

On Divergence of Hermite—Fejér Interpolation to f(z)=z in the Complex Plane

We show that for a broad class of interpolatory matrices on [-1,1] the sequence of polynomials induced by Hermite—Fejér interpolation to f(z)=z diverges everywhere in the complex plane outside the interval of interpolation [-1,1] . This result is in striking contrast to the behavior of the Lagrange interpolating polynomials. June 15, 1998. Date accepted: January 26, 1999.     

高维非均匀核N.N.估计的强一致收敛速度

本文讨论了高维空间中非均匀核Ｎ．Ｎ．Ｗ估计的一致强收敛强度。在密度数的条件与［１，２］相同时，得到了比［１，２］更好的收敛速度，就其收敛的主要部分而言已无可改进。由于均匀核Ｎ．Ｎ．估计是非均匀核Ｎ．Ｎ．估计的特例，从而大大拓广了Ｎ．Ｎ．估计的理论价值和应用范围。     

On a Problem of Daubechies

   Abstract. We solve a problem posed by Daubechies [12] by showing the nonexistence of orthonormal wavelet bases with good time-frequency localization associated with irrational dilation factors.     

集值映射的拟一致收敛

本文中，在拟一致空间中引入强局部对称性的概念，并讨论集值映射的拟一致收敛性．本文推广了［５］中的一些结果，同时用反例否定了［３］和［４］中的主要定理     

Fell—拓扑的某些性质

刻画了Fell-拓扑的某些性质以及Fell-拓扑和拓扑收敛的关系。     

Derivations of generalized Weyl algebras

A class of the associative and Lie algebras A[D] = A F[D] of Weyl type are studied, where A is a commutative associative algebra with an identity element over a field F of characteristic zero, and F[D] is the polynomial algebra of a finite dimensional commutative subalgebra of locally finite derivations of A such that A is D-simple. The derivations of these associative and Lie algebras are precisely determined.