n-Derivations of the Extended Schr(o)dinger-Virasoro Lie Algebra

Let (sb～) be the extended Schr(o)dinger-Virasoro Lie algebra and n ≥ 1 an integer.A map f: (sb～)n =(sb～) × (sb～) × … × (sb～) → (sb～) is called an n-derivation if it is a derivation inone variable while other variables fixed.We investigate n-derivations of the extendedSchr(o)dinger-Virasoro Lie algebra (sb～).The main result when n =2 is then applied tocharacterize the linear commuting maps and the commutative post-Lie algebra structureson (sb～).     

基于时域误差限的大规模系统自适应模型降阶

为满足解大规模动态系统常微分方程组对精度和速度权衡的要求,提出了一种基于误差限的大规模系统自适应模型降阶方法,其中方法的误差分析基于时域最大误差限,降阶方法基于SVD-Krylov子空间的方法.方法既考虑了算法的复杂性,又保证了算法的精度.通过对典型实例分析,结果表明该方法在给定相对误差限10~(-4)下得出的降阶阶数在不同频率下都能给出很好的近似精度,低频1~10Hz平均相对误差为1.1812×10~(-5),高频1~10GHz平均相对误差为5.6408×10~(-5),即在很宽的频率范围内都能满足精度要求.     

一类高阶非线性微分方程解的存在问题(英文)

This paper is concerned with the following n-th ordinary differential equation:{u～(n)(t)=f(t,u(t),u～(1)(t),···,u～(n-1) (t)),for t∈(0,1),u～(i) (0)=0,0 ≤i≤n3,au～(n-2)(0)du～(n-1)(0)=0,cu～(n-2)(1)+du～(n-1)(1)=0,where a,c ∈ R,,≥,such that a～2 + b～2 0 and c～2+d～20,n ≥ 2,f:[0,1] × R → R is a continuous function.Assume that f satisfies one-sided Nagumo condition,the existence theorems of solutions of the boundary value problem for the n-th-order nonlinear differential equations above are established by using Leray-Schauder degree theory,lower and upper solutions,a priori estimate technique.     

The Generalized Prime Number Theorem for Automorphic L-Functions

Let π and π' be automorphic irreducible cuspidal representations of GLm (QA) and GLm', (QA), respectively, and L(s,π×(～π)') be the Rankin-Selberg L-function attached to π and π'. Without assuming the Generalized Ramanujan Conjecture (GRC), the author gives the generalized prime number theorem for L(s, π×(～π)') when π(=)π'. The result generalizes the corresponding result of Liu and Ye in 2007.     

Rosetta: Landing on a comet

The European Space Agency will launch in January 2003 a mission called “Rosetta” to visit a comet. This space-craft will rendezvous with comet Wirtanen, follow it on its way to the sun in a close orbit and observe the comet core from this position. As part of the mission, a small package is carried, the “Rosetta Lander”, which separates and lands softly on the surface of the comet, where it will carry out a sequence of scientific investigations. Comets are amongst the most interesting bodies in our near space environment. They can be regarded as messengers from the time of formation of our planetary system, 4.5 billion years ago. A concise view on the origin and properties of comets in the context of the development history of our solar system is presented. The only direct information on comets available so far stems from the GIOTTO mission carried out during the last encounter with comet Halley in 1986. From the results obtained there, rough estimates are possible on the local environment near a comet and thus on the design requirements for a landing probe. The Rosetta mission follows a complicated flight path, which will reach the comet after a number of swing-by manoeuvres that use Mars and Earth to gain momentum. The information we have on comet 64P/Wirtanen is very limited. Therefore the final parameters for separation, descent and landing will be set after close observation of the target object by the Orbiter instruments. An overview will be given on the main components of the Lander, and short animations will be used to illustrate the Orbiter separation, descent and landing. The payload will be described, consisting of nine scientific instruments, chosen to complement each other in the fulfilment of the scientific objectives, which are discussed in some detail. Conferenza tenuta il giorno 27 Novembre 2000     

带有不等式约束的生长曲线模型中回归系数线性估计的泛容许性

对于带有不等式约束的生长曲线模型：Y=XBZ＋ε，ε^→～（0，σ^2V×I），tr（NB）≥0，本文在矩阵损失函数（d—KBL）（d—KBL）＇下，给出了可估函数KBL的线性估计的泛（西）容许性定义，分别得到了DYF和DYF＋C在齐次估计类LH和非齐次估计类LI中是KBL的泛容许性估计的充要条件．     

Symbolic computing algorithm for the method of successive approximations for near-parabolic orbits

In this paper, an accurate algorithm for the method of successive approximations for near-parabolic orbits is established symbolically. Numerical applications are given for motion predictions at fifteen epochs between the years 66 to 1835 for Halley’s comet, and at fifteen epochs between the years 1417 to 1782 for Encke’s comet. Comparisons with the standard Gauss method [4] show that the present algorithm is very accurate and efficient for motion predications of near-parabolic orbits.     

A Note on Generic Fiedler Matrices

In this paper, we first show that a generic m×n Fiedler matrix may have 2m-n-1 kinds of factorizations which are very complicated when m is much larger than n. In this work, two special cases are examined, one is an m×n Fiedler matrix being factored as a product of (m - n) Fiedler matrices, the other is an m×(m - 2) Fiedler matrix's factorization. Then we discuss the relation among the numbers of parameters of three generic m×n, n×p and m×p Fiedler matrices, and obtain some useful results.     

Determination of acridine in Non-aqueous Media

Acridine dissolved in the mixed solvent, ketone-acetic acid was determined by titrating with chlorosulphonic acid dissolved in the same solvent. The end-points were located by potentiometric, visual and photometric methods. The first method gave results with an error less than 1 per cent. and in the other two methods, the errors are less than 2 per cent in the estimation of semi-micro quantities of acridine.     

弱相依随机序列的若干新结果(英文)

设{Xn,n≥1}为-混合序列. 利用随机变量的截尾方法和-混合序列的三级数定理,讨论了-混合序列的收敛性质,并且得到了-混合序列的一类强极限定理,这些结果推广了独立序列的相应结果.最后研究了-混合序列加权和的强稳定性.     

求解带有非线性边界条件的涡流方程的A-φ解耦有限元格式

本文研究边界条件符合幂指数型非线性关系H × n = n × (|E × n|^α-1E × n)(0 < α ≤ 1)的涡流方程.使用A-φ耦合有限元格式数值求解这类问题具有较高精度,但计算开销大. A-φ解耦有限元计算格式能够在每个时间步上分别求解矢量A和标量φ,以此降低计算规模,提高计算效率.我们证明了解耦格式中解的存在唯一性,并且给出了它的误差估计.最后给出的数值实验证明了本文所提供的解耦算法是稳定和有效的.     

乘积型Morrey空间中乘积Hardy型算子的最佳界

本文得到了乘积Hardy型算子flm在乘积Morrey空间Lq,λ(Rn×…×Rn)和齐次中心Morrey空间Bq,λ(Rn×...× Rn)上的算子范数.基于旋转方法,我们推广了傅尊伟等人的结果(见[Houston J.Math.,2012,38(1):225-244]).     

本刊英文版Vol.29(2013),No.7论文摘要(英文)

<正>Rough Marcinkiewicz Integrals with Mixed Homogeneity on Product Spaces Feng LIU Huo Xiong WU Abstract In this paper,the parabolic Marcinkiewicz integral operators on the product spaces R^m×Rm×Rⁿ(m,n≥2)are studied.The Ln(m,n≥2)are studied.The L^p-boundedness for such operators are established under rather weak size conditions of the kernels,which essentially improve or extend certain previous results.     

具有特定纯净效应折中设计的若干理论及构造

许多因析试验中,试验者只关心指定的一部分因子效应的估计效果.针对此类问题,Addelman(1962)首次提出了折中设计的方法,并定义纯净折中设计以保证指定的因子效应被有效地估计出来,但此类纯净折中设计的分辨度限定为Ⅳ.本文研究了四类全新的折中设计,指定因子效应的集合分别记为{G1,G1×G1}、{G1,G1×G1,G...     

二阶算子矩阵代数中的全可导点V

研究二阶算子矩阵代数中的全可导点.利用线性映射与算子矩阵代数运算,以及套代数理论的相关结果,给出并证明了第二行第二列元素为可逆算子,其余元素为零算子的二阶矩阵是二阶算子矩阵代数的关于强算子拓扑的全可导点,推广了相关文献中的结果.     

两个完全图的乘积的树宽

本文确定了乘积图Km×Kn的树宽.我们的结果是若m和n都是偶数,且m≥n,或m是奇数而n是偶数,或m和n都是奇数且n≥m,则Km×Kn的树宽是TW(Km×Kn)=n(m+1)/2-1.这恰好是图Km×Kn的带宽.     

三阶矩阵的平方根

给出3×3矩阵的平方根公式，并通过实例阐明我们的方法，完善了有关文献中的某些结果．     

ρ混合阵列的收敛性

该文引入了ρ～混合阵列的概念，讨论了ρ～混合阵列的完全收敛性与依概率收敛性. 所得结果，推广了行独立随机变量阵列相应的结果. 此外还得到了一般随机变量阵列的完全收敛性与依概率收敛性.     

图K_nH_((5n/2)-4)的升分解

Ａｌａｖｉ等人给出了图的升分解的概念并猜测任何一个有正数条边的图都可以升分解．Ｆａｕｄｒｅｅ等１９８７年证明了当完全图Ｋｎ的子图Ｈ至多有ｎ—１条边时，Ｋｎ－Ｈ可以升分解．马克杰等１９９７年证明了当Ｈ至多含有ｎ条边时，Ｋｎ－Ｈ可以升分解．作者１９９９年证明了当Ｈ的边数小于３ｎ／２时，Ｋｎ－Ｈ可以升分解．本文将证明当Ｈ的边数小于（５ｎ／２）－４时Ｋｎ－Ｈ有升分解．