$\mathbb{C}^n$中一类星形映射子族的增长定理及推广的Roper-Suffridge算子

在有界星形圆形域上定义了一个新的星形映射子族, 它包含了$\alpha$阶星形映射族和$\alpha$阶强星形映射族作为两个特殊子类. 给出了此类星形映射子族的增长定理和掩盖定理. 另外, 还证明了Reinhardt域$\Omega_{n,p_{2},\cdots,p_{n}}$上此星形映射子族在Roper-Suffridge算子 \begin{align*} F(z)=\Big(f(z_{1}),\Big(\frac{f(z_{1})}{z_{1}}\Big)^{\beta_{2}}(f'(z_{1}))^{\gamma_{2}}z_{2},\cdots, \Big(\frac{f(z_{1})}{z_{1}}\Big)^{\beta_{n}}(f'(z_{1}))^{\gamma_{n}}z_{n}\Big)' \end{align*} 作用下保持不变, 其中 $\Omega_{n,p_{2},\cdots,p_{n}}=\{z\in {\mathbb{C}}^{n}:|z_1|^2+|z_2|^{p_2}+\cdots + |z_n|^{p_n}<1\}$, $p_{j}\geq1$, $\beta_{j}\in$ $[0, 1]$, $\gamma_{j}\in[0, \frac{1}{p_{j}}]$满足$\beta_{j}+\gamma_{j}\leq1$, 所取的单值解析分支使得 $\big({\frac{f(z_{1})}{z_{1}}}\big)^{\beta_{j}}\big|_{z_{1}=0}=1$, $(f'(z_{1}))^{\gamma_{j}}\mid_{{z_{1}=0}}=1$, $j=2,\cdots,n$. 这些结果不仅包含了许多已有的结果, 而且得到了新的结论.     

$L^{p}_{[0,1]}$空间M\"{u}ntz有理逼近的Jackson型估计 (英)

设$\Lambda=\{\lambda_{n}\}_{n=1}^{\infty}$为正的实数数列, 且当$n\rightarrow\infty$时, 有$\lambda_{n}\searrow 0$.本文给出了当 $\lambda_{n}\leq Mn^{-\frac{1}{2}},\;n=1,2, \cdots ,$(其中$M>0$为一正常数)时M\"{u}ntz系统$\{x^{\lambda_n}\}$的有理函数在$ L_{[0,1]} ^{p}$空间的逼近速度,主要结论为$R_{n} (f, \Lambda )_{L^{p}}\leq C_M \omega (f, n^{-\frac{1}{2}})_{L^{p}},\;1 \leq p \leq \infty.$     

亚纯函数微分多项式f^kQ[f]+P[f]的零点分布

研究了超越亚纯函数$f$的微分多项式$f^kQ[f]+P[f]$的零点分布. 给出了以下结果:对于满足$\delta(\infty,f)\geq1-\alpha>0$ ($\alpha$为常数, $0\leq \alpha<1$ )的超越亚纯函数$f(z)$, 若$T(r,f)=O((\log r)^2)$,则微分多项式$f^kQ[f]+P[f]$ ($Q[f]\not\equiv 0,\ P[f] \not\equiv 0$)在 可数个圆盘并集之外有无穷多个零点,其中$k>\frac{1+\Gamma_{P}+\gamma_{P}+\alpha(1+\Gamma_Q+\Gamma_{P}-\gamma_{P})} {1-\alpha }$, $\Gamma_{Q}$是$Q[f]$的权, $\Gamma_{P}$和$\gamma_{P}$是$P[f]$的权和次数.     

加权Dirichlet 空间上的一般Ces$\grave{a}$ro算子

对加权Dirichlet空间${\cal D}_{\alpha}=\left\{f\in H(D) ; ||f||_{{\cal D}_{\alpha}}^{2}=|f(0)|^{2}+\int_{D}|f'(z)|^{2}(1-|z|)^{\alpha}\d m(z)<+\infty \right\},~~-1<\alpha<+\infty,$我们研究了其上一般Ces$\grave{a}$ro算子的有界性. 此处$H(D)$表示复平面单位圆盘$D$上全纯函数的全体.     

变系数混合效应模型

本文研究了下列变系数混合效应模型: $y_{ij}=z_{ij}^{\tau}b_i+x_{ij}^{\tau}\beta(w_{ij}) +\xe_{ij},\;i=1,\cdots,m;\;j=1,\cdots,n_i$, 其中$b_i$为i.i.d.期望为$\xt$, 协方差阵为$\xs^2_bI_q$的随机效应向量, $\xe_{ij}$是i.i.d.期望为零, 具有有限方差的随机误差. 文中我们不仅给出了函数系数向量$\xb(\cdot)$的局部多项式估计, 同时给出了随机效应期望、方差和随机误差方差的估计, 并给出了这些估计量的渐进正态性和相合性, 研究结果表明了这些估计量的可靠性.     

在Banach空间中推广的 Roper-Suffridge算子(III)

假定 $X$ 是具有范数$\|\cdot\|$的复 Banach 空间, $n$ 是一个满足 $\dim X\geq n\geq2$的正整数. 本文考虑由下式定义的推广的Roper-Suffridge算子 $\Phi_{n,\beta_2, \gamma_2, \ldots , \beta_{n+1}, \gamma_{n+1}}(f)$: \begin{equation} \begin{array}{lll} \Phi _{n, \beta_2, \gamma_2, \ldots, \beta_{n+1},\gamma_{n+1}}(f)(x) &;\hspace{-3mm}=&;\hspace{-3mm}\dl\he{j=1}{n}\bigg(\frac{f(x^*_1(x))}{x^*_1(x)})\bigg)^{\beta_j}(f''(x^*_1(x))^{\gamma_j}x^*_j(x) x_j\\ &;&;+\bigg(\dl\frac{f(x^*_1(x))}{x^*_1(x)}\bigg)^{\beta_{n+1}}(f''(x^*_1(x)))^{\gamma_{n+1}}\bigg(x-\dl\he{j=1}{n}x^*_j(x) x_j\bigg),\nonumber \end{array} \end{equation} 其中 $x\in\Omega_{p_1, p_2, \ldots, p_{n+1}}$, $\beta_1=1, \gamma_1=0$ 和 \begin{equation} \begin{array}{lll} \Omega_{p_1, p_2, \ldots, p_{n+1}}=\bigg\{x\in X: \dl\he{j=1}{n}| x^*_j(x)|^{p_j}+\bigg\|x-\dl\he{j=1}{n}x^*_j(x)x_j\bigg\|^{p_{n+1}}<1\bigg\},\nonumber \end{array} \end{equation} 这里 $p_j>1 \,( j=1, 2,\ldots, n+1$), 线性无关族 $\{x_1, x_2, \ldots, x_n \}\subset X $ 与 $\{x^*_1, x^*_2, \ldots, x^*_n \}\subset X^* $ 满足 $x^*_j(x_j)=\|x_j\|=1 (j=1, 2, \ldots, n)$ 和 $x^*_j(x_k)=0 \, (j\neq k)$, 我们选取幂函数的单值分支满足 $(\frac{f(\xi)}{\xi})^{\beta_j}|_{\xi=0}= 1$ 和 $(f''(\xi))^{\gamma_j}|_{\xi=0}=1, \, j=2, \ldots , n+1$. 本文将证明: 对某些合适的常数$\beta_j, \gamma_j$, 算子$\Phi_{n,\beta_2, \gamma_2, \ldots, \beta_{n+1}, \gamma_{n+1}}(f)$ 在$\Omega_{p_1, p_2, \ldots , p_{n+1}}$上保持$\alpha$阶的殆$\beta$型螺形映照和 $\alpha$阶的$\beta$型螺形映照.     

A Hypothesis Testing Problem in the Linear Model (in English)

本文讨论了多元线性模型中的一个假设检验问题。假定 $\[{E(Y) = A\theta + B\eta }\]$ $Y的各行独立、正太、同协差阵V$ 现在要检验假设H_0:存在矩阵C使$\theta= C\eta$ 是否成立。首先可将问题化为法式的形式，对法式分两种情况进行讨论： （一）$[V = {\sigma ^2}I,{\sigma ^2}\]$未知，此时可求出 \theta,C，\sigma ^2的最大似然估计（当 H^0成立时）是 $[\left\{ {\begin{array}{*{20}{c}} {\hat \theta = {{({I_p} + \hat C'\hat C)}^{ - 1}}({y_1} + \hat C'{y_2})}\{\hat C = - {{({{T'}_{22}})}^{ - 1}}{{T'}_{12}}}\{{{\hat \sigma }^2} = \frac{1}{{nk}}(\sum\limits_{j = p + 1}^{p + q} {\lambda _j^* + \sum\limits_{j = 1}^k {{d_j})} } } \end{array}} \right.\]$ 其中y_1,y_2是法式 $[E\left( {\begin{array}{*{20}{c}} {{y_1}}\{{y_2}}\{{y_3}} \end{array}} \right) = \left( {\begin{array}{*{20}{c}} \theta \\eta \0 \end{array}} \right)\begin{array}{*{20}{c}} p\q\{n - (p + q)} \end{array}\]$ 中的资料阵y_1,y_2,d_1,\cdots，d_k是y^'_3y_3的全部特征根，$[\lambda _1^* \ge \cdots \lambda _{p + q}^*\]$是$[\left( {\begin{array}{*{20}{c}} {{y_1}}\{{y_2}} \end{array}} \right)\left( {\begin{array}{*{20}{c}} {{{y'}_1}}&{{{y'}_2}} \end{array}} \right)\]$的全部特征根，相应特征向量依$\lambda^*_i$的大小顺序从左到右排成矩阵T，T的分块子阵是T_ij，即 $[T = \left( {\begin{array}{*{20}{c}} {{T_{11}}}&{{T_{12}}}\{{T_{21}}}&{{T_{22}}} \end{array}} \right)\begin{array}{*{20}{c}} p\q \end{array}\]$ 对H_0的广义似然比检验是 $[\Lambda = \sum\limits_{j = p + 1}^k {{\lambda _j}/\sum\limits_{j = 1}^k {{d_j}} } \]$ $=lambda_1 \geq \lambda_2 \geq \cdots \geq \lambda_k$是$y_1^'y_1+y_2^'y_2$的全部特征根。 （二）一般情形V未知，此时 \theta,C的估计量同前，可求出 $[\hat V = \frac{1}{n}({y_2}^\prime {T_{22}}{T_{22}}^\prime {y_2} + {y_2}^\prime {y_2})\]$ H_0相应的Lawley不变检验是 $[\sum\limits_{j = p + 1}^k {{\beta _j}} \ge {\alpha _1}\]$ 其中 $\beta_1 \geq \beta_2 \geq \cdots \beta_k$是$y'_1y_1+y'_2y_2$的相应于$y'_sy_s$的全部特征根。 有关$\Lambda \$的以及$[\sum\limits_{j = p + 1}^k {{\beta _j}} \]$的极限分布将在另外的文章中讨论。     

Controllability and Observability of Discrete Systems (in English)

本文考虑有限维空间E_n的线性动力系统$\frac{dx}{dt}=Ax+Bu,u \in E_r$,与其有关的离散系统$x_k+1=f(A)x_k+g(A)Bu_k$的完全能控性和完全能观性的关系。\lambda_1,\lambda_2,\cdots,\lambda_n表示A的n个特征根，对应的初等因子最大阶数为e_1,e_2,\cdots,e_n，则得到： 定理1 如果$\frac{dx}{dt}=Ax+Bu$是完全能控的单输入系统，那么$x_k+1=f(A)x_k+g(A)Bu_k$是完全能控的充要条件是$g(\lambda_)\ne 0$当$\lambda_i \ne \lambda_j$,当e_i>1时$f'(\lambda_i) \ne 0$ 定理2 在多输入情形，定理1的条件是充分的。 应用对偶原理的到对应的完全能观性结果。     

一类非牛顿流体模型解的渐近性态(英)

本文主要讨论一类带 $p \,\,( 1+\frac{2n}{n+2} \leq p<3 )\,$ 幂增长耗散位势的非牛顿流体模型解的渐近性态, 利用改进的 Fourier分解方法, 证明了其解在$L^2$ 范数下衰减率为 $(1+t)^{-\frac{n}{4}}$.     

在Freud正交多项式零点处的Gr\"{u}nwald插值算子的收敛性

设$W_{\beta}(x)=\exp(-\frac{1}{2}|x|^{\beta})~(\beta > 7/6)$ 为Freud权, Freud正交多项式定义为满足下式$\int_{- \infty}^{\infty}p_{n}(x)p_{m}(x)W_{\beta}^{2}(x)\rd x=\left \{ \begin{array}{ll} 0 & \hspace{3mm} n \neq m , \\ 1 & \hspace{3mm}n = m \end{array} \right.$的     

一个素变量丢番图问题

设k和r是满足k≥3及r≥Ψ(k)+1的正整数,这里当3≤k≤4时,Ψ(k)=2~(k-1);而当k≥5时,Ψ(k)=1/2k(k+1).假定δ和ε是给定的足够小的正数,λ_1,λ_2,…,λ_(r+1)是不全同号且两两之比不全为有理数的非零实数.对于任意实数η与0σ2~(1-2k)/r-1,证明了:存在一个正数序列X→+∞,使得不等式|λ_1p_1~k+λ_2p_2~k+···+λ_rp_r~k+λ_(r+1)p_(r+1)+η|(max(1≤j≤r+1)p_j)~(-σ)有》■X~(■-(2~(1-2k))/(r-1)+ε组素数解(p_1,p_2,…,p_(r+1)),这里(δX)~(1/k)≤p_j≤X~(1/k)(1≤j≤r)及δX≤p_(r+1)≤X.这改进了之前的结果.     

关于两个素数和一个素数k次幂的丢番图不等式

令■设λ_1,λ_2,λ_3是不全同号的非零实数,且满足λ_1/λ_2为无理数,则对于任意实数η和ε 0,不等式■有无穷多组素数解p_1,p_2,p_3.该结果改进了Gambini,Languasco和Zaccagnini的结果.     

On the General Algebraic Inverse Eigenvalue Problems

A number of new results on sufficient conditions for the solvability and numerical algorithms of the following general algebraic inverse eigenvalue problem are obtained: Given $n+1$ real $n\times n$ matrices $A=(a_{ij}),A_k=(a_{ij}^{(k)})(k=1,2,\cdots,n)$ and $n$ distinct real numbers $\lambda_1,\lambda_2,\cdots,\lambda_n,$ find $n$ real number $c_1,c_2,\cdots,c_n$ such that the matrix $A(c)=A+\sum\limits_{k=1}^{n}c_k A_k$ has eigenvalues $\lambda_1,\lambda_2,\cdots,\lambda_n.$     

On sums of biquadratic powers with almost equal primes

The Ramanujan Journal - For $$18\le s\le 20,$$ we prove that for any sufficiently large positive integer N satisfying local conditions $$\mathcal N_s$$ the equation $$ N=p_{1}^{4}+p_{2}^{4}+\cdots...     

HUA’S THEOREM WITH FIVE ALMOST EQUAL PRIME VARIABLES

It is proved that each sufficiently large integer N=5(mod24) can be written as N=p1^2+p2^2+p3^2+p4^2+p5^2 with|pj=√N/5|&#177;、≤U=N^1/2-1/35+e,where pj ae primes.This result,which is obtained by an iterative method and a hybrid estimate for Dirichlet polynomial, improves the previous results in this direction.     

双线性分数次积分算子交换子在Morrey空间上有界的充分必要条件

In this paper,we obtain that b∈ BMO(R~n) if and only if the commutator[b,I_α]is bounded from the Morrey spaces L~(p_1,λ_1)(R~n)×L~(p_2,λ_2)(R~n) to L~(q,λ)(R~n),for some appropriate indices p,q,λ,μ.Also we show that b ∈ Lip_β(R~n) if and only if the commutator[b,I_α]is bounded from the Morrey spaces L~(p_1,λ_1)(R~n)×L~(p_2,λ_2)(R~n) to L~(q,λ)(R~n),for some appropriate indices p,q,λ,μ.     

关于有限域上一类方程解的个数

Let Fq be a finite field with q = pf elements,where p is an odd prime.Let N(a1x12 + ···+anxn2 = bx1 ···xs) denote the number of solutions(x1,...,xn) of the equation a1x12 +···+ anxn2 = bx1 ···xs in Fnq,where n 5,s n,and ai ∈ F*q,b ∈ F*q.In this paper,we solve the problem which the present authors mentioned in an earlier paper,and obtain a reduction formula for the number of solutions of equation a1x21 + ··· + anxn2 = bx1 ···xs,where n 5,3 ≤ s n,under a certain restriction on coefficients.We also obtain an explicit formula for the number of solutions of equation a1x21 + ··· + anxn2 = bx1 ···xn-1 in Fqn under a restriction on n and q.     

3个素数平方和的非线性型的整数部分

假设λ,μ,υ是不全为负的非零实数,λ是无理数,k是正整数,则存在无穷多素数p_1,p_2,p_,p,3使得[λp_1~2+μp_2~2+υp_3~2]=kp.特别地,[λp_1~2+μp_2~2+υp_3~2]表示无穷多素数.     

The integral part of a nonlinear form with five cubes of primes*

This paper shows that if μ ₁ , . . . , μ ₅ are nonzero real numbers, not all negative, at least one of μ _j $ \left( {1\leqslant j\leqslant 5} \right) $ is irrational, and k is a positive integer, then there exist infinitely many primes p ₁ , . . . , p ₅ , p such that $ \left[ {{\mu_1}p_1^3+\cdots +{\mu_5}p_5^3} \right]=kp $ . In particular, $ \left[ {{\mu_1}p_1^3+\cdots +{\mu_5}p_5^3} \right] $ represents infinitely many primes.