二维抛物型方程的高精度多重网格解法

提出了数值求解二维抛物型方程的一种新的高精度加权平均紧隐格式，利用Fourier分析方法证明了该格式是无条件稳定的，为了克服传统迭代法在求解隐格式是收敛速度慢的缺陷，利用了多重网格加速技术，大大加快了迭代收敛速度，提高了求解效率，数值实验结果验证了方法的精确性和可靠性。     

Ranks of Solutions of the Matrix Equation AXB = C

The purpose of this article is to solve two problems related to solutions of a consistent complex matrix equation AXB = C : (I) the maximal and minimal ranks of solution to AXB = C , and (II) the maximal and minimal ranks of two real matrices X₀ and X₁ in solution X = X₀ + iX₁ to AXB = C . As applications, the maximal and minimal ranks of two real matrices C and D in generalized inverse (A + iB)^- = C + iD of a complex matrix A + iB are also examined.     

Critical exponent for semilinear damped wave equations in the N-dimensional half space

We generalize a previous result of Ikehata (Math. Methods Appl. Sci., in press), which studies the critical exponent problem of a semilinear damped wave equation in the one-dimensional half space, to the general N-dimensional half space case. That is to say, one can show the small data global existence of solutions of a mixed problem for the equation u_tt−Δu+u_t=|u|^p with the power p satisfying p∗(N)=1+2/(N+1)<p?N/[N−2]+ if we deal with the problem in the N-dimensional half space.     

ON THE EQUATION $\square\phi =|\nabla \phi |^2$ IN FOUR SPACE DIMENSIONS

This paper considers the following Cauchy problem for semilinear wave equations in $n$ space dimensions $$\align \square\p &=F(\partial\p ),\\p (0,x)&=f(x),\quad \partial_t\p (0,x)=g(x), \endalign$$ where $\square =\partial_t^2-\triangle$ is the wave operator, $F$ is quadratic in $\partial\p$ with $\partial =(\partial_t,\partial_{x_1},\cdots ,\partial_{x_n})$. The minimal value of $s$ is determined such that the above Cauchy problem is locally well-posed in $H^s$. It turns out that for the general equation $s$ must satisfy $$s>\max\Big(\frac{n}{2}, \frac{n+5}{4}\Big).$$ This is due to Ponce and Sideris (when $n=3$) and Tataru (when $n\ge 5$). The purpose of this paper is to supplement with a proof in the case $n=2,4$.     

A NOTE ON REGULARITY AND EXISTENCE OF SOLUTIONS FOR A CLASS OF NON－UNIFORMLY DEGENERATE ELLIPTIC EQUATIONS

ＡＮＯＴＥＯＮＲＥＧＵＬＡＲＩＴＹＡＮＤＥＸＩＳＴＥＮＣＥＯＦＳＯＬＵＴＩＯＮＳＦＯＲＡＣＬＡＳＳＯＦＮＯＮ－ＵＮＩＦＯＲＭＬＹＤＥＧＥＮＥＲＡＴＥＥＬＬＩＰＴＩＣＥＱＵＡＴＩＯＮＳ￥ＬＩＪＵＮＪＩＥ（Ｄｅｐｔ．ｏｆＭａｔｈ．，ＺｈｅｊｉａｎｇＵｎｉ...     

关于一类拟线性拟抛物方程解的Blow─up问题

本文利用Ｆｏｕｒｉｅｒ空间的比较原理研究一类拟线性拟抛物方程解的Ｂｌｏｗ－ｕｐ问题，并给出了其解在有限时刻Ｂｌｏｗ－ｕｐ的条件。     

一个广义Bihari型不等式及其应用

本文对定义于一定有序局部紧空间上的向量值函数建立一个Ｂｉｈａｒｉ型积分不等式，并给出其对于非线性Ｖｏｌｔｅｒｒａ型积分方程的若干应用。     

The Cauchy Problem for a Class of Semilinear Wave Equations with Piecewise Constants Data

ＴｈｅＣａｕｃｈｙＰｒｏｂｌｅｍｆｏｒａＣｌａｓｓｏｆＳｅｍｉｌｉｎｅａｒＷａｖｅＥｑｕａｔｉｏｎｓｗｉｔｈＰｉｅｃｅｗｉｓｅＣｏｎｓｔａｎｔｓＤａｔａＺｈａｎｇＹｏｎｇｑｉａｎ（张永前）（ＩｎｓｔｉｔｕｔｅｏｆＭａｔｈｅｍａｔｉｃｓ，ＦｕｄａｎＵｎ...     

Solutions to the Equation of Non－Newtonian Polytropic Filtration Under Optimal Condition On Initial Values

Ｓｏｌｕｔｉｏｎｓ　ｔｏ　ｔｈｅ　Ｅｑｕａｔｉｏｎ　ｏｆ　Ｎｏｎ－Ｎｅｗｔｏｎｉａｎ　Ｐｏｌｙｔｒｏｐｉｃ　Ｆｉｌｔｒａｔｉｏｎ　Ｕｎｄｅｒ　Ｏｐｔｉｍａｌ　Ｃｏｎｄｉｔｉｏｎ　Ｏｎ　Ｉｎｉｔｉａｌ　ＶａｌｕｅｓＹｕａｎＨｏｎｇｊｕｎ（袁洪君）（Ｄｅ...     

Equilibrium theory for the hard-core systems

It is found that the density expansion in the argument of the exponential function gives a fine convergence on the equation of state of the hard-sphere system. The pair distribution function and the equation of state is constructed by an intuitive kinetic theoretical method. The equation of state of the hard-core system with attractive potential is constructed semiempirically with the aid of this simple analytical result, and Kamerling-Onnes' constant of the critical point is obtained analytically.