不可解性

There are series of papers studying the solvability of an incompressible, viscous, instationary fluid contained in a domian bounded entirely by a free surface. In 1977, Solonnikov proved its local solvability in a Holder space for any initial date but without surface tension. In 1984, he considered the same problem in a Sobolev space with surface tension being taken into account. In I992, Mogilevskii and Solonnikov treated the same problem in a Holder space, where the coefficient of surface tension is not a constant. There are also short-time existence results for the solvability of an incompressible, vicous, unsteady fluid bounded above by a free surface and below by a fixed bottom which approach horizontal planes at infinity. In 1981, Beale proved its local solvability in a Sobolev space for any initial date but without surface tension. In 1983, Allain were concerned with the same problem in R〓 with surface tension but under the assumption that the initial fluid domain was near a horizontal strip. In 1987, he obtained the same result without the preceding assumption. In 1996, Tani solved the same problem in R with surface tension. For the solvability of an incompressible viscous instationary fluid in Ω R bounded inside by a free surface S and outside by a rotating boundary S, in 1995 Ciuperca proved its local existence in a Sobolev space for any initial date but without surface tension. In this paper, we consider the same problem with surface tension.

对于边界完全是由自由边界组成的有界区域中粘性不可压流体的非定常运动问题，Solonnikcv于1977年在忽略表面张力情况下证明了初值问题小时间解在Holder空间的存在性，于1984年在有表面张力情况下证明了初值问题问题小时间解在Sobolev空间的存在性，Mogilevskii和Solonnikov于1992年在表面张力系数可以不是常数情况下证明了初值问题小时间解在Holder空间的存在性；对于上面是自由边界、下面是固定边界且两边界在无限处趋于水平的无限区域中粘性不可压流体的非定常运动问题，Beale于1981年在忽略表面张力情况下证明了初值问题小时间解在Sobolev空间的存在性，Allain于1983年在有表面张力情况下证明了R中初值问题小时间解在Sobolev空间的存在性，但其中假定初始区域近似是个水平条，他于1987年去掉了这个假定得到同样的结果，Tani于1996年在有表面张力情况下证明了R中初值问题小时间解在Sobolev空间的存在性；对于R中内面是自由边界、外面是旋转边界S的有界区域中粘性不可压流体的非定常运动问题，Ciuperca于1995年在忽略表面张力情况下证明了初值问题小时间解在Sobolev空间的存在性，本文考虑了在有表面张力情况下初值问题可解性问题。

Firstly, it's proved that the base of free monoid is unique, and that the equation of a base, a generating set and a irreducible generating set in the semigroup with length; Secondly, it's given the relation of a primitive word and a word of indecomposable--Let and is indecomposable, then is primitive ;And by using the length's method and chart,some properties of primitive word have been proved and the solutions of the equation , are discussed; Lastly, on the base of some proposition in Free monoids and Languages ,the proofs of some properties are improved by instruction. For example: Let be a primitive word over X, where .Then is a code. And let then if and only if {} is a code.

首先，讨论了含幺半群中基的基本性质及基与最小生成元集的联系，并给出了含幺半群中基、生成元集、不可约生成元集三者之间的关系；证明了在有唯一长度的半群S中，不可约生成元集、基、最小生成元集三者之间的等价关系；其次，讨论了字的组合与分解性，得出了字的本原性与不可分解性之间的关系---若为不可分解的，则一定是本原的，反之，不一定真；并运用图示法证明了字的可补性理论，讨论了方程，的可解性；在此基础上，用归纳法进一步证明了本原字与码的有关命题--若是X上的一个本原字，其中，则是一个码；若则当且仅当{}是一个码。

Turing Machines, A Brief Introduction to the Undecidability, Intractability and Complexity of Problems.

图灵机，问题的不可解性、难解性和复杂性等计算理论初步知识。

For the group representation, this paper improves the known method of determining the irreducibility. Instead of solving equations and checking every combination of the roots, we calculate the value of a polynomial.

对于自由群的表示，本文首先将不可约性的判别方法，由已有文献中解方程，并对方程的根作组合的方法，改进为直接计算某个多项式的值的方法，并进一步给出区分绝对不可约性和非绝对不可约性的判别准则。

The third part of this paper aims to study the global solvability or nonsolvability of a semilinear parabolic equation with singular potential.

论文的第三部分是对带奇异项的半线性抛物方程的整体可解性和不可解性的研究。

The steady-state solution is known to be the positive eigenfuction corresponding to the simple eigenvalue 0 of the system operator.

于是作为半群拟紧性和不可约性的直接结果，得到了系统的时间依赖解指数收敛到其静态解，并且该静态解即为系统算子简单特征值0对应的正的特征向量。

With the idea of smoothing Newton method, we propose a new class of smoothing Newton methods for the nonlinear complementarity problem based on a class of special functions. In this paper, complementarity problem is converted into a series of smoothing nonlinear equations and a modified smoothing Newton algorithm is used to solve the equations. We use Newton direction and Gradient direction together in the algorithm which guarantees that our method is globally convergent. Also using another smoothing function, we reformulate the generalized nonlinear complementarity problems defined on a polyhedral cone as a system of smoothing equations and a smooth unconstrained optimization problem. Theoretical results that relate the stationary points of the merit function to the solution of the generalized nonlinear complementarity problems are presented, we use the modified smoothing Newton algorithm in generalized nonlinear complementarity problems, under mild hypothesis, a global convergence is proved.

本文一方面基于现有的各种光滑Newton法的思想和半光滑理论，利用著名的F-B互补函数的光滑形式，首先将互补问题的求解转化为求解一系列光滑的非线性方程组，然后给出了一种修正的光滑Newton法，该方法不仅放宽对函数F的要求，在Newton方程不可解时引入初始效益函数的最速下降方向，而且光滑因子的选择也比较简单可行，同时在适当的条件下，证明了其算法具有全局收敛性；另一方面，借助另一种F-B光滑函数，将多面体锥上的广义互补问题转化为一种光滑形式，讨论了优化问题的稳定点与广义非线性互补问题的解之间的理论关系，并将这种修正的光滑Newton法用于求解广义非线性互补问题中，在适当的条件下，该算法同样具有全局收敛性。

The paper introduces several important notions such as uncountability and halting problem firstly,the fact is proved by contradiction that halting problem is impossible problem,and the same to other relative issues in computer is proved by reduction.

本文先介绍了不可数性和停机问题等重要概念，用反证法证明了停机问题是不可解的，并使用归约法对计算机中的相关问题的不可解性进行了证明。

Finally, this course introduces the students to deep scientific issues in the foundation of computing such as undecidability, complexity, and quantum computers.

最后，该课程向学生介绍在计算理论基础方面深层次的科学问题，如不可解性、复杂性和量子计算。

This paper discusses the drawing of hyperbola normal through a point outside the hyperbola and points out the unsolvability of geometric drawing method and the unintegrality of optimization method.

对过双曲线外一定点的法线作图问题作了探讨，提出了几何作图法的不可解性及优化法解的不全性。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。