Volume 14,Issue 2,1991 Table of Contents

1 SPATIAL COHERENCE OF LIGHT EMITTED FROM OPTIC FIBER

Pan Yingjun

1991, 14(2):8-14.

[Abstract](588) [HTML](0) [PDF 252.34 K](1523)

Abstract:
The mathmatic model of light emitted from optic fiber as source is given, and physical characteristics of the light is discussed. The relationsghip between V number of optic fiber,and coherent length & mean intensity extension of light emitted from fiber with a Gaussian intensity distribution is obtained in the Franhauf diffraction domain. The comparasion between this theory and diffraction field of incoherent source agrees with Van Cittert-Zernike law is made. The experimental result conincides with theory.

2 MULTIOBJECTIVE FRACTIONAL PROGRAMMING WITH SET FUNCTIONS

Yang Xinmin Duan Yurong

1991, 14(2):15-22.

[Abstract](577) [HTML](0) [PDF 253.95 K](879)

Abstract:
Systematically discusses the fundamental theorems of weak efficient solution, efficient solution and properly efficient solution for multiobjective fractional programming problems with set functions. Under suitable conditions, we give some theorems connecting multiobjective fractional programming with set functions and its scalarization problems as well as the corresponding saddle point problems.

3 THE EXTENCE OF NONTRIVIAL SOLUTIONS FOR NONLINEAR ELLIPTIC EQUATIONS INVOLVING CRITICAL SOBOLEV EXPONENTS

He Chuanjiang

1991, 14(2):23-31.

[Abstract](681) [HTML](0) [PDF 250.36 K](1100)

Abstract:
讨论了有界区域上的Dirichlet问题-△u-λu=α(x)│u│~(p-1)u+f(x,u),x∈Ω,u=0,x∈Ω非平凡解的存在性。其中 p=(n+2)/(n-2),n≥3,f(x,u)是关于│u│的增涨阶低于p的连续函数,λ是正参数。我们先证明了一个不具(PS)条件的临界点定理。据此并利用Sobolev嵌入定理的最优常数,克服了失去紧性的困难,从而得到非平凡解的存在性。与Brezis—Nirenberg结果不同的是,我们没有假设λ<λ_1,λ_1是-△:H_0~1(Ω)→H~(-1)(Ω)的第一本征值。

4 A CLASS OF CUBIC PARAMETER CURVES OF B-SPLINE TYPE WITH ARBITRARY PARAMETER

Zhao Xuejun

1991, 14(2):40-46.

[Abstract](760) [HTML](0) [PDF 198.00 K](871)

Abstract:
A class of cubic parameter curve of B-spline type is constructed in this paper with four arbitrary parameters, the cubic Hermite curve, Ball curve, Bezier curve, Timmer curve and B-spline curve as its special cases. The condition in which the curves contact with each edge of characteristic polygon is also given. In order to satisfy the actual riquirements,the shape(i. e. location of end point,direction of convixity and flexion,etc. )of curves can be modified by adjusting the four parameters.

5 THE SECOND ORDER PERTURBATION ANALYSIS OF FREQUENCY RESPONSE FUNCTION OF STRUCTURE WITH NON-PROPORTIONAL CHANGEABLE; DAMPING

Zhang Xiangwei Xu Meihe

1991, 14(2):47-55.

[Abstract](669) [HTML](0) [PDF 302.85 K](895)

Abstract:
A simplified procedure is presented for the determintion of rates of change of frequency response function matrix of system for the non-proportional changeable damping ,by means of the second order perturbation technique in conjunction with complex modal analysis. Consequently, when excitation information in frequency domain is known,the sensitivity of the response power spectra and the response time history can be obtained.

6 AN IMPROVED TRANSFER SUBSTRUCTURE METHOD

Zhu Tianguo

1991, 14(2):56-63.

[Abstract](726) [HTML](0) [PDF 250.97 K](1049)

Abstract:
The transfer substructure method is extended to application in substructures with different linking ways,thus the field of application of this method is expanded. Its relaibility and efficacy are proved by some examples.

7 A NEWLY METHOD OF RESEARCHING BLOOD THIXOTROPY

Wang Bochu

1991, 14(2):73-78.

[Abstract](553) [HTML](0) [PDF 210.63 K](1058)

Abstract:
Based on analysis of formation and dissolution of thixotropy of human blood ,this paper provides a new method to discribe constitutive relations of blood thixotropy . Two parameters act as reasonable parameters as thixtropic degree function and index function , for appraising thixotropy of blood.

8 THE EFFECTS OF HEAT CONDUCTING CROSS-SECTION AREA AND AXIAL HEAT CONDUCTION ON THE HEAT TRANSFER IN THE TUBE-MOUTH REGION OF THE HIGH TEMPERATURE HEAT EXCHANGE EQUIPMENT

Li Longjian Zhang Hongji

1991, 14(2):79-84.

[Abstract](644) [HTML](0) [PDF 328.78 K](1050)

Abstract:
In this paper the heat transfer in the tube-mouth region of the high temperatur heat exchange equipment is deeply analysed. The effect; of the heat conducting cross-section area of the tube-mouth region and axial heat conduction along the tube on the temperature field is emphatically examined by numerical computation, and then the relation of the highest temperature in the tube with the elongated tube length is established. The computed results in this paper are compared with those without taking account of these two factors. It is shown that the effect can not be ignored for the corrosion-protection by controlling temperature.

9 THE EFFECTS OF RESTRAINT STRESS ON PHASE TRANSFORMATION AND FRACTURE TOUGHNESS IN WELD HAZ OF 15MnMoVNRE STEEL

Zheng Zijiu Huang Weigang

1991, 14(2):90-95.

[Abstract](674) [HTML](0) [PDF 311.83 K](173)

Abstract:
The effects of restraint stress on phase transformation and fracture toughness COD in weld HAZ of 15MnMoVNRE steel were studied by means of weld thermal simulation and COD testing. The results show that restraint stress accelerates phase transformation and makes the fracture toughness COD higher.

10 RESEARCH ON THE MECHANISM OF GAS OUTBURST INITATION IN MINES

Du Yungui Tan Xueshu Xian Xuefu

1991, 14(2):104-109.

[Abstract](627) [HTML](0) [PDF 291.69 K](148)

Abstract:
The mechanism of coal-gas outburst iniration is comprehensively analysed. The direct courses of initating coal-gas outburst are the sudden loss of confining stresses and the gas pressure gradient in coal seam. The effects of working face's advancing rate, geological conditions and gas pressure gradient as well as mechanical & physical characteristics of coal on outburst initation are expounded by means of mathematic analyses about gas seepage which takes place in coal seams. The results are of certain practical significance and reference value to further quantitive study of outburst and its predication.

11 MEASUREMENT ON THE SOUND POWER LEVEL FOR MECHANICAL NOISE

Yu Jiliang

1991, 14(2):110-114.

[Abstract](827) [HTML](0) [PDF 178.51 K](170)

Abstract:
Because of changeable distribution of noise fields in different room and the different absorption coefficients of walls and ceilings, average absorption coefficient of room surface hase to be estimated,which is really a great trouble . Now,this problem is solved,because,as discribed in this paper, the mechanical noise of the A weighted sound power level can be calculated after the absorption coefficient and environmental correction value is obtained. Experiences show that the result is accurate enough for engineering practice.

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