锥度量空间中的一些新的拓扑性质（英文）

本文给出了锥度量空间中的锥的一些性质.利用完备性概念,得到了此空间中的闭球套定理,改进了前人在度量空间中的相应结果.     

锥度量空间中的一些新的拓扑性质

本文给出了锥度量空间中的锥的一些性质.利用完备性概念,得到了此空间中的闭球套定理,改进了前人在度量空间中的相应结果.     

鞅Hardy空间与Hardy-Orlicz空间的鞅变换

利用鞅变换,刻画了鞅Hardy空间与Hardy-Orlicz空间之间的相互关系:当p_Φ+∞时,证明了Hardy-Orlicz空间H_Φ~s中的鞅是Hardy空间H_1~s中的鞅变换;反之,H_1~s中的鞅也是H_Φ~s中的鞅变换.所得结果推广了已有文献中的相应结论.     

距离网点集在E~n中的分治嵌入法及其应用

提出了一种距离网点集在Euclid空间中的分治嵌入法,讨论了距离界网点集在Euclid空间中的嵌入问题以及在生物大分子结构计算中的应用。     

En空间中张角定理及其应用

本文利用单形的体积公式,得到了n维欧氏空间En中的张角定理,由此又证得了单形中的一组恒等式,利用这组恒等式给出了Safta猜想在En空间中的加强形式.     

Kleene蕴涵算子的导出算子的n值逻辑系统In

考虑了Kleene蕴涵算子的导出算子的三值逻辑系统I3 和n值逻辑系统In(n >3)。首先,给出I3的真值表,证明了I3 是二值逻辑系统C2 的推广。其次,讨论了I3 中的重言式与IPC公理之间以及I3 中的准重言式与C2 中的重言式之间的关系。接着,考虑了In中的子代数。最后,考虑了不同逻辑系统In中的重言式之间的关系     

复Clifford分析中的复k-超单演函数

首先给出了复Clifford分析中的复k-超单演函数的定义,进一步得到了复Clifford分析中的复k-超单演函数的一些等价条件,从而使复Clifford分析中的复k-超单演函数与其满足的方程之间建立了联系.     

关于“复域上二阶多项式自治系统代数曲线解的不存在性”的注记

本文沿袭了文 [1 ]中的方法 ,将文 [1 ]中的结论作了进一步的推广 .     

模糊逻辑系统公理真度分析

分别对Lukasiewicz逻辑系统中的公理在R0系统和G(o)del系统中的真度大小、R0系统逻辑系统中的公理在Lukasiewicz系统和中G(o)del系统的真度大小和G(o)del逻辑系统中的公理在R0系统和Lukasiewicz系统中的真度大小进行了计算和分析,从真度方面研究和分析了常用逻辑系统之间的关系.     

FC-度量空间中的R-KKM定理及其对变分不等式和不动点的应用

引入了FC-度量空间,建立了非紧FC-度量空间中的R-KKM定理.作为应用,研究了非紧FC-度量空间中的变分不等式的解集、相交点集、Ky Fan截口和极大元集的性质,获得了FC-度量空间中的Fan-Browder不动点定理.     

Frames for operators

Frames in Hilbert spaces are a redundant set of vectors which yield a representation for each vector in the space. In the present paper, we give a generalization of frames, which allows, in a stable way, to reconstruct elements from the range of a linear and bounded operator in a Hilbert space.     

On farthest points of sets

For a convex closed bounded set in a Banach space, we study the existence and uniqueness problem for a point of this set that is the farthest point from a given point in space. In terms of the existence and uniqueness of the farthest point, as well as the Lipschitzian dependence of this point on a point in space, we obtain necessary and su.cient conditions for the strong convexity of a set in several infinite-dimensional spaces, in particular, in a Hilbert space. A set representable as the intersection of closed balls of a fixed radius is called a strongly convex set. We show that the condition “for each point in space that is sufficiently far from a set, there exists a unique farthest point of the set” is a criterion for the strong convexity of a set in a finite-dimensional normed space, where the norm ball is a strongly convex set and a generating set.     

Uniqueness of transonic shock solutions in a duct for steady potential flow

We study the uniqueness of solutions with a transonic shock in a duct in a class of transonic shock solutions, which are not necessarily small perturbations of the background solution, for steady potential flow. We prove that, for given uniform supersonic upstream flow in a straight duct, there exists a unique uniform pressure at the exit of the duct such that a transonic shock solution exists in the duct, which is unique modulo translation. For any other given uniform pressure at the exit, there exists no transonic shock solution in the duct. This is equivalent to establishing a uniqueness theorem for a free boundary problem of a partial differential equation of second order in a bounded or unbounded duct. The proof is based on the maximum/comparison principle and a judicious choice of special transonic shock solutions as a comparison solution.     

Mechanical properties of polypropylene modified by decomposition products of alkali sulfate lignin

During processing of polypropylene and alkali sulfate lignin at a temperature of 180° C, a reaction occurs resulting in the formation of a polymer which appears to have a three-dimensional structure. The observed cross-linking is accompanied by an increase in reversible deformation, a decrease in irreversible deformation, a transition from solubility to limited swelling in solvents, an increase in tensile strength, and an increase in freeze resistance. This is achieved by also adding a plasticizer to the polymer.Mekhanika Polimerov, Vol. 1, No. 6, pp. 3–9, 1965     

3‐D spatio–temporal structures of biofilms in a water channel

We develop a numerical predictive tool for multiphase fluid mixtures consisting of biofilms grown in a viscous fluid matrix by implementing a second‐order finite difference discretization of the multiphase biofilm model developed recently on a general purpose graphic processing unit. With this numerical tool, we study a 3‐D biomass–flow interaction resulting in biomass growth, structure formation, deformation, and detachment phenomena in biofilms grown in a water channel in quiescent state and subject to a shear flow condition, respectively. The numerical investigation is limited in the viscous regime of the biofilm–solvent mixture. In quiescent flows, the model predicts growth patterns consistent with experimental findings for single or multiple adjacent biofilm colonies, the so‐called mushroom shape growth pattern. The simulated biomass growth both in density and thickness matches very well with the experimentally grown biofilm in a water channel. When shear is imposed at a boundary, our numerical studies reproduce wavy patterns, pinching, and streaming phenomena observed in biofilms grown in a water channel. Copyright © 2014 John Wiley & Sons, Ltd.     

A Linear Programming Construction of Fully Optimal Bases in Graphs and Hyperplane Arrangements

The fully optimal basis of a bounded acyclic oriented matroid on a linearly ordered set has been defined and studied by the present authors in a series of papers, dealing with graphs, hyperplane arrangements, and oriented matroids (in order of increasing generality). This notion provides a bijection between bipolar orientations and uniactive internal spanning trees in a graph resp. bounded regions and uniactive internal bases in a hyperplane arrangement or an oriented matroid (in the sense of Tutte activities). This bijection is the basic case of a general activity preserving bijection between reorientations and subsets of an oriented matroid, called the active bijection, providing bijective versions of various classical enumerative results.Fully optimal bases can be considered as a strenghtening of optimal bases from linear programming, with a simple combinatorial definition. Our first construction used this purely combinatorial characterization, providing directly an algorithm to compute in fact the reverse bijection. A new definition uses a direct construction in terms of a linear programming. The fully optimal basis optimizes a sequence of nested faces with respect to a sequence of objective functions (whereas an optimal basis in the usual sense optimizes one vertex with respect to one objective function). This note presents this construction in terms of graphs and linear algebra.     

锥中调和函数的下界及其应用

本文首先给出锥中一类调和函数的下界,所得结果推广了张艳慧、邓冠铁和高洁欣在半空间中的相关结论;作为应用,接着证明了锥中的Levin型定理;最后,给出了锥中Dirichlet问题解积分表示形式的唯一性定理.     

Contractibility and Connectedness of Efficient Point Sets

Using the technique of space theory and set-valued analysis, we establish contractibility results for efficient point sets in a locally convex space and a path connectedness result for a positive proper efficient point set in a reflexive space. We also prove a connectedness result for a positive proper efficient point set in a locally convex space; as an application, we give a connectedness result for an efficient solution set in a locally convex space.     

Explosive instability in nonlinear waves in media with negative viscosity : PMM vol. 38, n 6, 1974, pp. 991–995

The propagation of a wave of a finite amplitude in a medium with a nonlinearity of the second degree and negative viscosity, is examined. It is shown that in a finite time singularities appear in the solution. The exact solution of the Cauchy problem is given for a specific case. Recently the effects of negative viscosity which cause an increase in the energy of the wave motion have been studied intensively in electrodynamics, plasma physics, the Earth's atmosphere, in the theory of the circulation of the oceans and of flow in open channels [1–4], Wave amplification caused by an energy transfer from turbulent to regular motions, is possible in any medium having space-time fluctuations, provided the correlation time is sufficiently small [5, 6]. As the wave amplitude increases, nonlinear effects become important; they have been taken into account in cases where the interaction of a finite number of harmonics [2, 4] and the structure of steady motions have been examined [3].It is shown in this paper that in a medium with negative viscosity and a second degree dynamic nonlinearity, a solution of the Cauchy problem for an arbitrary “good” form of the initial perturbation, exists over a finite time interval. An example of such a solution is given.     

政府花费改变对经济影响的理论分析

本文采用无限期内生时间偏好率模型,研究了政府花费对经济的影响.指出长期的政府花费增加可以使资本存量水平上升,消费水平下降和债券持有量上升;同时,短期分析表明政府花费增加可以减少初始投资率,增加政府债务率水平;但短期的政府花费增加同样导致资本存量水平上升,消费水平下降和债务水平的增加.