JOURNAL OF BEIJING INSTITUTE OF TECHNOLOGY

Han Botang

1997, 6(1): 1-8.

[Abstract](318) [PDF 451KB](19)

Abstract:
Let q be a positive integer.The graphs,called the q-trees are defined by recursion:the smallest q-tree is the complete graph K_qwith q vertices,and a q-tree with n+1 vertices where n≥q is obtained by adding a new vertex adjacent to each of q arbitrarily selected but mutually adjacent vertices of q-tree with n vertices.Obviously,1-trees are the graphs which are generally called trees.In this paper,it is proved that for any positive integer q,q-tree is reconstructible.

Maximum Number of Edges of （rK_t）-Free Graphs

Sun Liang, Yang Gang

1997, 6(1): 9-13.

[Abstract](236) [PDF 252KB](19)

Abstract:
With positive integers r,t and n,where n≥rt and t≥2,the maximum number of edges of a simple graph of order n is estimated,which does not contain r disjoint copies of K_rfor r=2 and 3.

The Precise Order and Singular Directions of Meromorphic Functions

Zhang Xuelian

1997, 6(1): 14-18.

[Abstract](249) [PDF 252KB](19)

Abstract:
The rnemmorphic functions of positive order(both finite positive order and infinite order) are discussed.First,the precise order and type function are given by using the characteristic function.Then some singular directions are defined and their existence is proved.

Determinant Theory in Banach Algebras

Xu Tianzhou

1997, 6(1): 19-24.

[Abstract](238) [PDF 316KB](20)

Abstract:
A determinant theory is developed for Banach algebras and a characterization of those traced unital Banach algebras admitting a determinant is given.

Invariant Determinants in Banach Algebras

Xu Tianzhou

1997, 6(1): 25-29.

[Abstract](178) [PDF 277KB](20)

Abstract:
The invariant determinants ha Banach algebras are discussed and a necessary and sufficient condition for those integral traced unital Barach algebra(A,τ) admitting a G-invari- ant determinant is obtained,where G is a group of trace preserving automorphisms of A.

On the Dynamics of Controlled Diffusions

Yang Mingyan, Mei Fengxiang

1997, 6(1): 30-36.

[Abstract](285) [PDF 369KB](19)

Abstract:
Treats of dynamical systems with finite number of degrees of freedom such that the time evolution of the configuration variables for given initial conditions can well be described by controlled diffusions.Two suitable forms of stochastic action associated with the controlled diffusions are introduced in the general framework of stochastic control theory.By discretizing the stochastic action,the dynamical equations for the controlled diffusions of the given systems are derived in terms of generalized coordinates.These equations,together with the continuity equation,describe exactly the probability approach of the diffusion motion.

Continuous Pseudocolor Encoding of Thermal Image Display

Li Wei

1997, 6(1): 37-42.

[Abstract](235) [PDF 313KB](23)

Abstract:
The visual features of continuous pseudocolor encoding is discussed and the optimiz- ing design algorithm of continuous pseudocolor scale is derived.The algorithm is restricting the varying range and direction of lightness,hue and saturation according to correlation and naturalness,automatically calculating the chromaticity coordinates of nodes in uniform color space to get the longest length of scale path,then interpolating points between nodes in equal color differences to obtain continuous pseudocolor scale with visual uniformity.When it was applied to the pseudocolor encoding of thermal image displays,the results showed that the correlation and the naturalness of original images and cognitive characteristics of target pattern were reserved well;the dynamic range of visual perception and the amount of visual information increased obviously;the contrast sensitivity of target identification improved;and the blindness of scale design were avoided.

Synthesis and Characterization of Side-Chain Liquid Crystalline Polysiloxanes

Dai Rongji, Fu Ruonong

1997, 6(1): 43-51.

[Abstract](273) [PDF 448KB](19)

Abstract:
Side chain liquid crystalline golysiloxanes conta ing biphenyl and benzyl ether mesogen were synthesized by the hydrosilation of poly（methylhydrcsiloxane） with 4-（4-allyloxybenzytoxy）-4'- methoxybiphenyl（M₁）,4-（4-allyloxybenzyloxy）-4'-ethoxybiphenyl（M₂）,4-（4-allyloxybenzyloxy）-4'- propoxybiphenyl（M₃）,4-（4-allyloxybenzyloxy）-4'-butoxybiphenyl（M₄）,4-（4-allyloxybenzyloxy）-4'- pentyloxybiphenyl（M₅）.The phase behavior of monomeric and polymeric liquid crystals was chararcterized by differential scanning calorimetry and optical polarization microscopy.Both the monomeric and polymeric liquid crystals exhibit liquid crystal behaviors.

Study on Capillary Zone Electrophoretic Separation of Chlorpheniramine Enantiomers with β-Cyclodextrin

Li Fang, Jin Hui, Gu Junling, Fu Ruonong

1997, 6(1): 52-58.

[Abstract](224) [PDF 505KB](19)

Abstract:
The chlorpheniramine enantiomers were separated with capillary zone electrophoresis using β-cyclodextrin as the chiral selector.The effects of the concentration of β-cyclodextrin, the electrolyte pH and organic modifier(urea) on the difference in apparent electrophoretic mobilities of the enantiomels were investigated.

Effective Moduli of Two-Layered Spherical Inclusions Reinforced Composites

Hu Gengkai

1997, 6(1): 59-66.

[Abstract](256) [PDF 435KB](19)

Abstract:
A model is proposed to evaluate the,effective modufi of a composite reinforced by two-layered spherical inclusions.This model is based on the localisation problem of a two- layered spherical inclusion embedded in an infinite matrix.The interations of the reinforced phases are taken into account by using the average matrix stress concept.When the external layer vanishes,the proposed model reduces to the classical Mori-Tanaka's model for spherical inclusions.Theoretical results for the composite of polyester matrix filled by hollow glass spheres and voids show excellent agreement with experimental results.

Failure Mechanism of CVD Coated Carbide Tools

Pang Siqin

1997, 6(1): 67-71.

[Abstract](197) [PDF 424KB](19)

Abstract:
Through systematically theoretical analysis and experimental research,the failure mechanism,of CVD(chemical vapor deposition) coated carbide tools in wear and fracture conditions was studied.On the basis of mechanism analysis,the specific suitability of the coated tools for cutting conditions was revealed and clarified.

A New Approach to Prediction of Fault of Manufacturing Quality for FMS

Zhang Zhijing, Wang Xinyi, Zhu Xiaoyan

1997, 6(1): 72-77.

[Abstract](269) [PDF 319KB](19)

Abstract:
This paper makes a study of the cause of manufacturing fault,develops the and/or- fault-tree of manufacturing quality fault for MC,and presents a new concept of faint manufacturing quality fault(FMQF)and the decision making tree with which the fault of manufacturing system would be found out from FMQF.An approach to identification of FMQF,based on fuzzy set theory,is presented,which can be used for estimating the status of equipment with the deviation of control charts.Based on the study above,an expert system for the flexible manufacturing system's FMQF detection and prediction is built.

The Design and Implementation of an Object-Oriented Hypermedia System

Cao Yuanda, Ma Rui

1997, 6(1): 78-84.

[Abstract](270) [PDF 367KB](20)

Abstract:
Presents an object-oriented NBO(node-block-object)data model for hypermedia system.It takes advantage of object-oriented method,encapsulates all multimedia information as well as link functions in one unit,It has successfully achieved cross link to offer much better flexibility and two-way link to realize forward and backward searching in hypermedia system navigation.A conditional relation on links has also been realized,that is very helpful for time sensitive multimedia information processing and multimedia object cooperation.

Feature Relationship and Process Planning

Lu Jiping, Ning Ruxin

1997, 6(1): 85-91.

[Abstract](245) [PDF 373KB](19)

Abstract:
Concurrent engineering(CE)involves the consideration during the design phase of the various factors associated with the life cycle of the product.Using the principle of CE,a feature-based CAPP system is proposed.On the basis of feature modeling,the system is able to reason feature relationships,produce feature digraph of a part,and decide the machining sequence of features.

Mathematical Models of Tire-Lateral Road Adhesion for Use in Road Vehicle Dynamics Studies

Liu Zhaodu

1997, 6(1): 92-99.

[Abstract](334) [PDF 390KB](22)

Abstract:
Mathematical models of tire-lateral mad adhesion for use in mad vehicle dynamics studies are set up to express the relations of adhesion coefficients with slip ratio in lateral direction.The models of tire-lateral mad adhesion revolutionize the Pacejka's model in concept and therefore make it possible for applications in vehicle dynamics studies by the expression of lateral adhesion coefficient as a function of wheel slip ratio,instead of the wheel slip angle,taking into account in the mean time the influences of mad surface condition, vehicle velocity,vertical load,tire slip angle,and wheel camber angle.

1997 Vol. 6, No. 1