共查询到20条相似文献，搜索用时 31 毫秒
1.
In this paper we generalize the method used to prove the Prime Number Theorem to deal with finite fields, and prove the following
theorem:
|
$
\pi (x) = \frac{q}
{{q - 1}}\frac{x}
{{\log _q x}} + \frac{q}
{{(q - 1)^2 }}\frac{x}
{{\log _q^2 x}} + O\left( {\frac{x}
{{\log _q^3 x}}} \right),x = q^n \to \infty
$
\pi (x) = \frac{q}
{{q - 1}}\frac{x}
{{\log _q x}} + \frac{q}
{{(q - 1)^2 }}\frac{x}
{{\log _q^2 x}} + O\left( {\frac{x}
{{\log _q^3 x}}} \right),x = q^n \to \infty
相似文献
2.
In this paper we discuss the fundamental solution of the Keldysh type operator $
L_\alpha u \triangleq \frac{{\partial ^2 u}}
{{\partial x^2 }} + y\frac{{\partial ^2 u}}
{{\partial y^2 }} + \alpha \frac{{\partial u}}
{{\partial y}}
$
L_\alpha u \triangleq \frac{{\partial ^2 u}}
{{\partial x^2 }} + y\frac{{\partial ^2 u}}
{{\partial y^2 }} + \alpha \frac{{\partial u}}
{{\partial y}}
, which is a basic mixed type operator different from the Tricomi operator. The fundamental solution of the Keldysh type operator
with $
\alpha > - \frac{1}
{2}
$
\alpha > - \frac{1}
{2}
is obtained. It is shown that the fundamental solution for such an operator generally has stronger singularity than that
for the Tricomi operator. Particularly, the fundamental solution of the Keldysh type operator with $
\alpha < \frac{1}
{2}
$
\alpha < \frac{1}
{2}
has to be defined by using the finite part of divergent integrals in the theory of distributions. 相似文献
3.
For the solutions of the elliptic equation
|
$
\sum\limits_{k = 0}^n {A_k \frac{{\partial ^n f}}
{{\partial x^{n - k} \partial y^k }} = 0}
$
\sum\limits_{k = 0}^n {A_k \frac{{\partial ^n f}}
{{\partial x^{n - k} \partial y^k }} = 0}
相似文献
4.
By the Fourier method a solution of the equation |
相似文献
5.
Wavelet–type transform associated with singular Laplace–Bessel differential operator
is introduced and the relevant Calderón–type reproducing formula is established. Representations of the generalized Bessel potentials
0)$
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and their inverses via the wavelet–type transform are obtained. 相似文献
6.
This paper is devoted to studying the initial value problems of the nonlinear Kaup Kupershmidt equations δu/δt ＋ α1 uδ^2u/δx^2 ＋ βδ^3u/δx^3 ＋ γδ^5u/δx^5 = 0, （x,t）∈ E R^2, and δu/δt ＋ α2 δu/δx δ^2u/δx^2 ＋ βδ^3u/δx^3 ＋ γδ^5u/δx^5 = 0, （x, t） ∈R^2. Several important Strichartz type estimates for the fundamental solution of the corresponding linear problem are established. Then we apply such estimates to prove the local and global existence of solutions for the initial value problems of the nonlinear Kaup- Kupershmidt equations. The results show that a local solution exists if the initial function u0（x） ∈ H^s（R）, and s ≥ 5/4 for the first equation and s≥301/108 for the second equation. 相似文献
7.
Zeta-generalized-Euler-constant functions,
|
$
\gamma \left( s \right): = \sum\limits_{k = 1}^\infty {\left( {\frac{1}
{{k^s }} - \int_k^{k + 1} {\frac{{dx}}
{{x^s }}} } \right)}
$
\gamma \left( s \right): = \sum\limits_{k = 1}^\infty {\left( {\frac{1}
{{k^s }} - \int_k^{k + 1} {\frac{{dx}}
{{x^s }}} } \right)}
相似文献
8.
We study the rough bilinear fractional integral
|
$
\tilde B_{\Omega ,\alpha } (f,g)(x) = \int_{\mathbb{R}^n } {f(x + y)g(x - y)\frac{{\Omega (x,y')}}
{{\left| y \right|^{n - \alpha } }}dy} ,
$
\tilde B_{\Omega ,\alpha } (f,g)(x) = \int_{\mathbb{R}^n } {f(x + y)g(x - y)\frac{{\Omega (x,y')}}
{{\left| y \right|^{n - \alpha } }}dy} ,
相似文献
9.
Realization of Boolean functions in the class of oriented contact circuits (OCCs) with certain restrictions on the weight,
number, and types of adjacent contacts is studied. Oriented contact circuits are considered in which, from an arbitrary vertex,
at most λ arcs issue and at most ν different Boolean variables are used in the marks of the issuing arcs. The weight of a
vertex of an OCC is defined as being equal to λ if one arc enters a vertex and equal to λ(1 + ω), where ω > 0, otherwise.
Then, as usual, the weight of an OCC is defined as the sum of the weights of its vertices; the weight of a Boolean function,
as the minimum weight of OCCs realizing it; and Shannon function W
λ, ν, ω( n), as the maximum weight of the Boolean function of n variables. For this Shannon function, the so-called high-accuracy bound
|
$
W_{\lambda ,v,\omega } (n) = \frac{\lambda }
{{\lambda - 1}}\frac{{2^n }}
{n}\left( {1 + \frac{{\frac{{2\lambda - v - 2}}
{{\lambda - 1}}\log n \pm O(1)}}
{n}} \right),
$
W_{\lambda ,v,\omega } (n) = \frac{\lambda }
{{\lambda - 1}}\frac{{2^n }}
{n}\left( {1 + \frac{{\frac{{2\lambda - v - 2}}
{{\lambda - 1}}\log n \pm O(1)}}
{n}} \right),
相似文献
10.
In this paper, the sharp estimates of all homogeneous expansions for f are established, where f( z) = ( f
1( z), f
2( z), …, f
n
( z))′ is a k-fold symmetric quasi-convex mapping defined on the unit polydisk in ℂ
n
and
|
$
\begin{gathered}
\frac{{D^{tk + 1} + f_p \left( 0 \right)\left( {z^{tk + 1} } \right)}}
{{\left( {tk + 1} \right)!}} = \sum\limits_{l_1 ,l_2 ,...,l_{tk + 1} = 1}^n {\left| {apl_1 l_2 ...l_{tk + 1} } \right|e^{i\tfrac{{\theta pl_1 + \theta pl_2 + ... + \theta pl_{tk + 1} }}
{{tk + 1}}} zl_1 zl_2 ...zl_{tk + 1} ,} \hfill \\
p = 1,2,...,n. \hfill \\
\end{gathered}
$
\begin{gathered}
\frac{{D^{tk + 1} + f_p \left( 0 \right)\left( {z^{tk + 1} } \right)}}
{{\left( {tk + 1} \right)!}} = \sum\limits_{l_1 ,l_2 ,...,l_{tk + 1} = 1}^n {\left| {apl_1 l_2 ...l_{tk + 1} } \right|e^{i\tfrac{{\theta pl_1 + \theta pl_2 + ... + \theta pl_{tk + 1} }}
{{tk + 1}}} zl_1 zl_2 ...zl_{tk + 1} ,} \hfill \\
p = 1,2,...,n. \hfill \\
\end{gathered}
相似文献
11.
We study k
th
order systems of two rational difference equations
|
$
x_n = \frac{{\alpha + \sum\nolimits_{i = 1}^k {\beta _i x_{n - i} + } \sum\nolimits_{i = 1}^k {\gamma _i y_{n - i} } }}
{{A + \sum\nolimits_{j = 1}^k {B_j x_{n - j} + } \sum\nolimits_{j = 1}^k {C_j y_{n - j} } }},n \in \mathbb{N},
$
x_n = \frac{{\alpha + \sum\nolimits_{i = 1}^k {\beta _i x_{n - i} + } \sum\nolimits_{i = 1}^k {\gamma _i y_{n - i} } }}
{{A + \sum\nolimits_{j = 1}^k {B_j x_{n - j} + } \sum\nolimits_{j = 1}^k {C_j y_{n - j} } }},n \in \mathbb{N},
相似文献
12.
We study k
th
order systems of two rational difference equations
|
$
x_n = \frac{{\alpha + \sum\nolimits_{i = 1}^k {\beta _i x_{n - 1} + } \sum\nolimits_{i = 1}^k {\gamma _i y_{n - 1} } }}
{{A + \sum\nolimits_{j = 1}^k {B_j x_{n - j} + } \sum\nolimits_{j = 1}^k {C_j y_{n - j} } }}, y_n = \frac{{p + \sum\nolimits_{i = 1}^k {\delta _i x_{n - i} + } \sum\nolimits_{i = 1}^k {\varepsilon _i y_{n - i} } }}
{{q + \sum\nolimits_{j = 1}^k {D_j x_{n - j} + } \sum\nolimits_{j = 1}^k {E_j y_{n - j} } }} n \in \mathbb{N}
$
x_n = \frac{{\alpha + \sum\nolimits_{i = 1}^k {\beta _i x_{n - 1} + } \sum\nolimits_{i = 1}^k {\gamma _i y_{n - 1} } }}
{{A + \sum\nolimits_{j = 1}^k {B_j x_{n - j} + } \sum\nolimits_{j = 1}^k {C_j y_{n - j} } }}, y_n = \frac{{p + \sum\nolimits_{i = 1}^k {\delta _i x_{n - i} + } \sum\nolimits_{i = 1}^k {\varepsilon _i y_{n - i} } }}
{{q + \sum\nolimits_{j = 1}^k {D_j x_{n - j} + } \sum\nolimits_{j = 1}^k {E_j y_{n - j} } }} n \in \mathbb{N}
相似文献
13.
Let f( n) be a strongly additive complex-valued arithmetic function. Under mild conditions on f, we prove the following weighted strong law of large numbers: if X,X
1, X
2, … is any sequence of integrable i.i.d. random variables, then
|
$
\mathop {\lim }\limits_{N \to \infty } \frac{{\sum\nolimits_{n = 1}^N {f(n)X_n } }}
{{\sum\nolimits_{n = 1}^N {f(n)} }} = \mathbb{E}Xa.s.
$
\mathop {\lim }\limits_{N \to \infty } \frac{{\sum\nolimits_{n = 1}^N {f(n)X_n } }}
{{\sum\nolimits_{n = 1}^N {f(n)} }} = \mathbb{E}Xa.s.
相似文献
14.
Stochastic homogenization (with multiple fine scales) is studied for a class of nonlinear monotone eigenvalue problems. More
specifically, we are interested in the asymptotic behaviour of a sequence of realizations of the form
|
$
- div\left( {a\left( {T_1 \left( {\frac{x}
{{\varepsilon _1 }}} \right)\omega _1 ,T_2 \left( {\frac{x}
{{\varepsilon _2 }}} \right)\omega _2 ,\nabla u_\varepsilon ^\omega } \right)} \right) = \lambda _\varepsilon ^\omega \mathcal{C}\left( {u_\varepsilon ^\omega } \right)
$
- div\left( {a\left( {T_1 \left( {\frac{x}
{{\varepsilon _1 }}} \right)\omega _1 ,T_2 \left( {\frac{x}
{{\varepsilon _2 }}} \right)\omega _2 ,\nabla u_\varepsilon ^\omega } \right)} \right) = \lambda _\varepsilon ^\omega \mathcal{C}\left( {u_\varepsilon ^\omega } \right)
相似文献
15.
We consider semilinear partial differential equations in ℝ
n
of the form
|
$
\sum\limits_{\frac{{|\alpha |}}
{m} + \frac{{|\beta |}}
{k} \leqslant 1} {c_{\alpha \beta } x^\beta D_x^\alpha u = F(u)} ,
$
\sum\limits_{\frac{{|\alpha |}}
{m} + \frac{{|\beta |}}
{k} \leqslant 1} {c_{\alpha \beta } x^\beta D_x^\alpha u = F(u)} ,
相似文献
16.
In this paper, solutions for two types of ultrametric kinetic equations of the form reaction-diffusion are obtained and properties
of these solutions are investigated. General method to find the solution of equation of the form
|
$
\tfrac{\partial }
{{\partial t}}f(x,t) = \int_{\mathbb{Q}_p } {W(|x - y|_p )(f(y,t) - f(x,t))dy + V(|x|_p )f(x,t),f(x,0) = \phi (|x|_p ),}
$
\tfrac{\partial }
{{\partial t}}f(x,t) = \int_{\mathbb{Q}_p } {W(|x - y|_p )(f(y,t) - f(x,t))dy + V(|x|_p )f(x,t),f(x,0) = \phi (|x|_p ),}
相似文献
17.
Suppose that X is a complex Banach space with the norm ‖·‖ and n is a positive integer with dim X ⩾ n ⩾ 2. In this paper, we consider the generalized Roper-Suffridge extension operator $
\Phi _{n,\beta _2 ,\gamma _2 , \ldots ,\beta _{n + 1} ,\gamma _{n + 1} } (f)
$
\Phi _{n,\beta _2 ,\gamma _2 , \ldots ,\beta _{n + 1} ,\gamma _{n + 1} } (f)
on the domain $
\Omega _{p_1 ,p_2 , \ldots ,p_{n + 1} }
$
\Omega _{p_1 ,p_2 , \ldots ,p_{n + 1} }
defined by
|
$
\Phi _{n,\beta _2 ,\gamma _2 , \ldots ,\beta _{n + 1} ,\gamma _{n + 1} } (f)(x) = {*{20}c}
{\sum\limits_{j = 1}^n {\left( {\frac{{f(x_1^* (x))}}
{{x_1^* (x)}}} \right)} ^{\beta _j } (f'(x_1^* (x)))^{\gamma _j } x_1^* (x)x_j } \\
{ + \left( {\frac{{f(x_1^* (x))}}
{{x_1^* (x)}}} \right)^{\beta _{n + 1} } (f'(x_1^* (x)))^{\gamma _{n + 1} } \left( {x - \sum\limits_{j = 1}^n {x_1^* (x)x_j } } \right)} \\
$
\Phi _{n,\beta _2 ,\gamma _2 , \ldots ,\beta _{n + 1} ,\gamma _{n + 1} } (f)(x) = \begin{array}{*{20}c}
{\sum\limits_{j = 1}^n {\left( {\frac{{f(x_1^* (x))}}
{{x_1^* (x)}}} \right)} ^{\beta _j } (f'(x_1^* (x)))^{\gamma _j } x_1^* (x)x_j } \\
{ + \left( {\frac{{f(x_1^* (x))}}
{{x_1^* (x)}}} \right)^{\beta _{n + 1} } (f'(x_1^* (x)))^{\gamma _{n + 1} } \left( {x - \sum\limits_{j = 1}^n {x_1^* (x)x_j } } \right)} \\
\end{array}
相似文献
18.
Sunto Si studia il problema della determinazione di una soluzione dell'equazione
a k(x)∂ ku/∂x k=f(x, y) entro la semistriscia a≤x≤b, y≥0, che assuma assegnati valori per y=0 e per x=a, x 1, x 2, b (a<x 1<x 2<b). Analogamente si studia il problema della determinazione di una soluzione dell' equazione
a k(x)∂ ku/∂x k+b(x)∂u/∂y=f(x,y), entro la medesima semistriscia, cha assuma assegnati valori per y=0 e per x=a, x 1, x 2, b e la cui ∂/∂y assuma assegnati valori per y=0.
A Giovanni Sansone nel suo 70 mo compleanno. 相似文献
19.
In this paper, the author proves the existence and uniqueness of nonnegative solution for the first boundary value problem of uniform degenerated parabolic equation
$$\[\left\{ {\begin{array}{*{20}{c}}
{\frac{{\partial u}}{{\partial t}} = \sum {\frac{\partial }{{\partial {x_i}}}\left( {v(u){A_{ij}}(x,t,u)\frac{{\partial u}}{{\partial {x_j}}}} \right) + \sum {{B_i}(x,t,u)} \frac{{\partial u}}{{\partial {x_i}}}} + C(x,t,u)u\begin{array}{*{20}{c}}
{}&{(x,t) \in [0,T]}
\end{array},}\{u{|_{t = 0}} = {u_0}(x),x \in \Omega ,}\{u{|_{x \in \partial \Omega }} = \psi (s,t),0 \le t \le T}
\end{array}} \right.\]$$
$$\[\left( {\frac{1}{\Lambda }{{\left| \alpha \right|}^2} \le \sum {{A_{ij}}{\alpha _i}{\alpha _j}} \le \Lambda {{\left| \alpha \right|}^2},\forall a \in {R^n},0 < \Lambda < \infty ,v(u) > 0\begin{array}{*{20}{c}}
{and}&{v(u) \to 0\begin{array}{*{20}{c}}
{as}&{u \to 0}
\end{array}}
\end{array}} \right)\]$$
under some very weak restrictions, i.e. $\[{A_{ij}}(x,t,r),{B_i}(x,t,r),C(x,t,r),\sum {\frac{{\partial {A_{ij}}}}{{\partial {x_j}}}} ,\sum {\frac{{\partial {B_i}}}{{\partial {x_i}}} \in \overline \Omega } \times [0,T] \times R,\left| {{B_i}} \right| \le \Lambda ,\left| C \right| \le \Lambda ,\],\[\left| {\sum {\frac{{\partial {B_i}}}{{\partial {x_i}}}} } \right| \le \Lambda ,\partial \Omega \in {C^2},v(r) \in C[0,\infty ).v(0) = 0,1 \le \frac{{rv(r)}}{{\int_0^r {v(s)ds} }} \le m,{u_0}(x) \in {C^2}(\overline \Omega ),\psi (s,t) \in {C^\beta }(\partial \Omega \times [0,T]),0 < \beta < 1\],\[{u_0}(s) = \psi (s,0).\]$ 相似文献
20.
Abstract In this paper, we investigate the positive solutions of strongly coupled nonlinear parabolic systems with nonlinear boundary conditions： {ut-a（u, v）△u=g（u, v）, vt-b（u, v）△v=h（u, v）, δu/δη=d（u, v）, δu/δη=f（u, v）.Under appropriate hypotheses on the functions a, b, g, h, d and f, we obtain that the solutions may exist globally or blow up in finite time by utilizing upper and lower solution techniques. 相似文献
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