高铬镍合金钢中钛的测定

研究了大量铬、镍中钛的分离方法。在一定条件下使三价铬氧化成6价铬，再在氨性条件下使钛沉淀，大量铬、镍留在溶液中。将分离后的沉淀酸溶后用二氨替比林甲烷光度法测定钛。回收率为93．7％-102．4％。     

Weber's problem and weiszfeld's algorithm in general spaces

For solving the Euclidean distance Weber problem Weiszfeld proposed an iterative method. This method can also be applied to generalized Weber problems in Banach spaces. Examples for generalized Weber problems are: minimal surfaces with obstacles, Fermat's principle in geometrical optics and brachistochrones with obstacles.Wenn aber schon einmal Theorie getrieben werden soll, (man möchte die Vorliebe dafür angesichts gewisser missglückter Erscheinungen ja allerdings manchmal zum Teufel wünschen) so ist als eine ihrer Formen auch diejenige nötig, die die Abstraktion auf die Spitze treibt.Alfred Weber, 1909     

A critical index algorithm for nearest point problems on simplicial cones

We consider the linear complementarity problem (q, M) in whichM is a positive definite symmetric matrix of ordern. This problem is equivalent to a nearest point problem [; b] in which = {A.₁,, A. _n } is a basis for R ⁿ ,b is a given point in R ⁿ ; and it is required to find the nearest point in the simplicial cone Pos() tob. We develop an algorithm for solving the linear complementarity problem (q, M) or the equivalent nearest point problem [; b]. Computational experience in comparison with an existing algorithm is presented.Research effort partially supported by the Air Force Office of Scientific Research. Air Force Systems Command, USAF, under grant No. AFOSR 78-3646. The United States Government is authorized to reproduce and distribute reprints for governmental purposes, not withstanding any copyright notation hereon.     

On variational aspects of some nonconvex nonsmooth global optimization problem

The paper is devoted to study a global optimization problem for a class of nonsmooth, nonconvex and non-locally Lipschitz functionals on a vector-valued reflexive Banach space. The existence of an element which is both a global minimizer and a solution of the associated hemivariational inequality is proved under some unilateral growth restrictions imposed on nonlinearities and under the assumption that an appropriately modified version of the Hedberg truncation procedure can be applied.On leave from his original institute.     

Routing in grid graphs by cutting planes

In this paper we study the following problem, which we call the weighted routing problem. Let be given a graphG = (V, E) with non-negative edge weightsw _{e +} and letN,N 1, be a list of node sets. The weighted routing problem consists in finding mutually disjoint edge setsS ₁,...,S _N such that, for eachk {1, ...,N}, the subgraph (V(S _k),S _k) contains an [s, t]-path for alls, t T _k and the sum of the weights of the edge sets is minimal. Our motivation for studying this problem arises from the routing problem in VLSI-design, where given sets of points have to be connected by wires. We consider the weighted routing problem from a polyhedral point of view. We define an appropriate polyhedron and try to (partially) describe this polyhedron by means of inequalities. We describe our separation algorithms for some of the presented classes of inequalities. Based on these separation routines we have implemented a branch and cut algorithm. Our algorithm is applicable to an important subclass of routing problems arising in VLSI-design, namely to switchbox routing problems where the underlying graph is a grid graph and the list of node sets is located on the outer face of the grid. We report on our computational experience with this class of problem instances.     

Weighted Harmonic Bloch Spaces and Gleason's Problem

The harmonic function spaces are considered on the unit ball, which unify the Bloch space ( s = 1) and the Lipschitz spaces (0 < s < 1). This article presents a characterization of when s > 1 and gives a solution of Gleason's problem in for any s > 0.     

On the complexity of the k-customer vehicle routing problem

We investigate the complexity of the k-CUSTOMER VEHICLE ROUTING PROBLEM: Given an edge weighted graph, the problem requires to compute a minimum weight set of cyclic routes such that each contains a distinguished depot vertex and at most other k customer vertices, and every customer belongs to exactly one route.     

Routing and wavelength assignment in optical networks using bin packing based algorithms

This paper addresses the problem of routing and wavelength assignment (RWA) of static lightpath requests in wavelength routed optical networks. The objective is to minimize the number of wavelengths used. This problem has been shown to be NP-complete and several heuristic algorithms have been developed to solve it. We suggest very efficient, yet simple, heuristic algorithms for the RWA problem developed by applying classical bin packing algorithms. The heuristics were tested on a series of large random networks and compared with an efficient existing algorithm for the same problem. Results indicate that the proposed algorithms yield solutions significantly superior in quality, not only with respect to the number of wavelength used, but also with respect to the physical length of the established lightpaths. Comparison with lower bounds shows that the proposed heuristics obtain optimal or near optimal solutions in many cases.     

Slowly Oscilating Solutions of Diferential Equations with Delays

§１．ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｓｔｕｄｙｏｆｓｌｏｗｌｙｏｓｃｉｌａｔｉｎｇ（Ｓ．Ｏ．）ｓｏｌｕｔｉｏｎｓｏｆｄｅｌａｙｄｉｆｅｒｅｎｔｉａｌｅｑｕａｔｉｏｎｓｗａｓｉｎｉｔｉａｔｅｄｉｎｔｈｅ５０＇ｓｂｙｐｉｏｎｅｅｒｉｎｇｗｏｒｋｏｆＷｒｉ...     

The Characteristic Finite Volume Method for Nonlinear Convection-diffusion Problems

§ 1.Introduction　 The finite elementor finite difference methods along characteristics for convection-dif-fusion problems in an unbounded domain R have been developed by Douglas and Rus-sel[1 ] .In those problems with significant convection,the solution changes much lessrapidly in the characteristicτ direction than in time tdirection.Thus,the characteristic-type numerical methods will permitthe use of largertime steps,with corresponding im-provements in efficiency,at no cost in accuracy.　…