Volume 16,Issue 2,1993 Table of Contents

1 Switched-Capacitor Complex Filter and Its Application

Wu MingLiXin

1993, 16(2):1-7.

[Abstract](567) [HTML](0) [PDF 289.67 K](1184)

Abstract:
The realization of cascade connection and its application in negative-pass filtering of Switched-Capacitor Complex Filter(SCCF) are studied in this paper,in which a SC complex negative-pass filter is designed and its attenuation characteristics obtained by computer simulation are also presented.

2 A NEW FREQUENCY SYNTHESIS METHOD

Song Junshou Huang Kenyan Cao Rui Yan Fengqin Wu Yongxiang

1993, 16(2):8-13.

[Abstract](491) [HTML](0) [PDF 290.30 K](969)

Abstract:
A new frequency synthesis method is presented in this paper. Its fundamental ideology is that for any frequency needed to be output,the controller sends a different group of dividing numbers to the feedback programmable divider of PLL by means of a special algorithm so as to make the interference frequency at the output of the phase detector and the frequency resolution indeqendent from each other. Therefore,high resolution and wide bandwidth are achieved simultaneously.

3 A Vovel Constracture of Combinatorial Knowledge Base for the Expert System of Eletrical Switching

Li Jianzhong Wang Guanjie

1993, 16(2):14-18.

[Abstract](580) [HTML](0) [PDF 263.74 K](832)

Abstract:
By comparing the techniges of the production and the logic predicate for knowledge representation, this paper presents a kind of constructure of combinatorial knowledge base applied to the expert system for switch operation in electric power system . This constructure of knowledge base to be expanded and revised easily,and it is cinvenitnt to build the general shell of the expert system.

4 An Analysis of PWM Switched-Mode Voltage Regulation System with the Cross Double-Fed Control

Zhou Luowei Li Zaihua Hou Zhencheng

1993, 16(2):19-23.

[Abstract](551) [HTML](0) [PDF 227.06 K](1214)

Abstract:
The dynamical modelling of the new converter with the cross double-fed control system is set by using the averaging techniques. The dynamical quality and the stability of the new system are analyzed with the modelling,and compared with the ordinary converter. The results show that the dynamical quality and the stability of the new converter are much better than those of the ordinary one.

5 An Expert System Approach to the Computer Aided Design of Intelligent Controllers

Tu Yaqing Li Zushu Huang Shanglian

1993, 16(2):24-29.

[Abstract](811) [HTML](0) [PDF 365.09 K](1274)

Abstract:
The idea for an expert system approach to the computer aided design of intelligent controllers (ESCAD1C) is discussed and the idea of two step modelling of an intelligent controller is presented on the basis of emulating human control behaviours to solve complex problems. The structure, functions and characteristics of ESCADTC system , and the design procedures of intelligent controllers are gived. The knowledge base and simulating functions for designing intelligent controllers are also described.

6 A Kind of Adaptive Generalized Predictive Control for a Nonlinear System

Deng Rengming Wang Li

1993, 16(2):30-36.

[Abstract](666) [HTML](0) [PDF 270.31 K](939)

Abstract:
This paper,using Hammerstein model to express a kind of nonlinear system,presents a new kind of Adaptive Generalized Predictive control for Nonlinear systems(NAGPC). This method divides the whole system into two parts: linear subsystem and nonlinear one. In the first part,a new algorithm ,whose computation quantity is less and speed is faster,is developed according to the characteristics of gain controlling Matrix F in the Generalized Predictive Control (GPC). Mean while, the interpolation method is used to develop one step root solving procedure and the result can be used as the whole system input in the second part. Simulation studies show that the general algorithm NAGPC is strong in robustness,good in stability and fast in computation.

7 The Design and Implementation of An Expert Control System

Chen Minyou

1993, 16(2):37-43.

[Abstract](837) [HTML](0) [PDF 425.41 K](987)

Abstract:
This paper proposes an expert control system for industrial processes on-line control and supervision by combining expert system techniques with computer process control techniques, introduces the fundamental design principles,basic structure and engineering implementation of this real time expert control system and gives the field operation results concerning the processing of a sodium chromate rotary kiln controlled by this expert control system as an application example.

8 The Effect of Aspect Ratio on Natural Convection in a Cavity with Discrete Heaters and a Vertical Heat Sink

Chen Li Li Longjan Zhang Hongji

1993, 16(2):44-50.

[Abstract](819) [HTML](0) [PDF 377.62 K](186)

Abstract:
SIMPLE method is used to study the influence of aspect ratio on the natural convection in an enclosure with five discrete heat sources on a vertical wall and an isothermal heat sink on another vertical wall. The range of aspect ratio is from 3. 0 to 12. 22. At high aspect ratio, multiple secondary flow cells can be found,which enhance heat transfer strongly and cause the highest heat transfer coefficient based on cooling area Nuc. With the decrease of aspect ratio,secondary flow cells become weaker gradually and finally reach the lowest Nuc at H/W = 7. 35. If H/W continues to decrease,natural convection is gradually developed,and heat transfer is improved. At H/W = 3. 67,Nuc becomes stable. Then the decrease of aspect ratio will not affect heat transfer. Besides, A heat transfer correlation including the influence of aspect ratio is .also provided.

9 The Dissolution Characteristics of Rock Salt and Mass Transmission Process

Xiao Changfu Yang Youkui WuGangLi Changping Qiu Xiande

1993, 16(2):51-57.

[Abstract](599) [HTML](0) [PDF 380.04 K](236)

Abstract:
The dissolution separation of halite from rock salt and the mass transmisson of sodium chloride (NaCl) solution forming the dissolution process of rock salt are investigated. With the experimental studies of the dissolution characteristic of rock salt and the diffusion of sodium chloride (NaCl) solution. The changing regularity of the dissolution rate of rock salt and the separation coefficient with each primary influence factor,as well as the corresponding formulae are obtained. The dynamic differential equilibrium equations of rock salt solution are established.

10 The Advance in the Study of the Macromolecular Structure of Coals

Zhang Daijun Xian Xuefu

1993, 16(2):58-63.

[Abstract](1151) [HTML](0) [PDF 409.13 K](186)

Abstract:
The latest advance in the study of the macromolecular structure and macromolecules stacking structure of coals were reviewed. The viewpoint that there are complex variation and ordering in coal macromolecule stsructure is put forward. It is suggested that the macromolecular structure of coals be divided into three levels?the skeleton of carbon atoms (Basic Structural Unit), the metwork of cross-linking bonds and the edge groups in BSU.

11 A Study on Leaching Characteristics of Heavy Metal in Chongqing Life Garbage

Lei Qingru Qing Changhua Yan Wenjun

1993, 16(2):64-69.

[Abstract](617) [HTML](0) [PDF 320.48 K](159)

Abstract:
The researches on the static and dynamic leaching behaveor of heavy metals (Cu , Zn , Pb, Cd , Fe, Mn, Ni, Cr(N)) in Chongqing life garbage are summarized. The leaching Curves arc gained. The inquiring into the acting of ion-exchanging caused by hydric-ion on heavy metal's dyn mie leaching are the leaching behavior of heavy metals in dry and soaked garbage are made detailly using the static and dynamic leaching test data, the pollution of heavy metal from garbage' s leachate to environment is discussed generally.

12 Direct Factor Analysis With Discrete X-Ray Diffraction Patterns

Chen Changguo Liao Bogang

1993, 16(2):70-72.

[Abstract](435) [HTML](0) [PDF 163.11 K](193)

Abstract:
In this paper,we put forward a method of direct factor analysis with discrete X-ray diffraction patterns, which was supported by the experimental measurement with the mixture containing 2,3,4,5 phases respectively. The detailed discussion was also given to its principles,errors and criterion.

13 Oxidizing Characteristics of Phosphorus in Combined-Blowing Steelmaking Converter

Zhang Shujun Van Guangting Tang Ping

1993, 16(2):73-78.

[Abstract](765) [HTML](0) [PDF 300.98 K](206)

Abstract:
An analytical calculation is made on the basis of the experimental data from the oxidizing process of phosphorus in the combined-blowing converter. The oxidizing characteristics of phosphorus in the combined-blowing converter with natural gas as cooling medium is revealed and the advantages of the combined-blowing process is theoretically explained.

14 THE STUDY FOR LARGE INCLUSIONS OF STAINLESS STEEL (1Crl8Ni9Ti) DURING CONTINUOUS CASTING

Li Gang Wei Ruihang You Dingfang

1993, 16(2):79-83.

[Abstract](635) [HTML](0) [PDF 300.34 K](149)

Abstract:
This paper presents the process of stainless steel ( 1Crl8Ni9Ti) in continuous casting,the components and their shapes,origins and distributions of the large inclusions existing in the steel,as well as the influence on its quality. By the observation through a microscope,the structural analysis adopting x-ray examinating instrument and the measunement for the microzone of billet employing the electronic probe.it has been found that the large inclusions of continuous billet mainly originate from the slag-sweeping of the tundisy and mold. There are mostly spherical-slag in addition to Ti(C.N) in the inclusions. The calculations in theory point out that the siO2in the slag can' t change Ti(C,N) into TiO2,however,it can assimilate with Ti(C.N). The large inclusions affect the quality of the steel plate and tube greatly. As a result,this paper proposes the measures of reducing the large inclusions in the steel.

15 An Investigation on Measuring Surface Viscosity of Melting Slag

Bai Chenguang Pei Henian Zhang Xiulian Zhu Qunhua Zhou Peitu

1993, 16(2):84-87.

[Abstract](918) [HTML](0) [PDF 244.28 K](191)

Abstract:
Several methods of measuring surface vescosity are discussed. An appropriate method for measuring surface viscosity of melting slag- the laser method is proposed as well as an experimental device is set. With the device the surface viscosities of some aqueors liguids are measured. The results verify that the device is feasible and lays a good foundation for measuring the surface viscosity of melting slag.

16 An Analysis of the Scaling Failure of the Nodular Iron Composite Polls

Niu Yinyi Long Siyuan Li Ningqiang Li Daoheng Yang Jun

1993, 16(2):93-98.

[Abstract](669) [HTML](0) [PDF 315.55 K](163)

Abstract:
It is recognized that the scaling failure of nodular iron composite rolls in hot rolling is a problem of fatigue brittle fracture. The temperature field,stress,critical crack size as well as the interior quality of the rolls are presented. The theory of fracture mechanics is used to explain the cause of the scaling failure. At the same time, the way to extend the durability of the rolls is also studied.

17 A Fractal Model of the Microstructure

He Zongyan Gao Zhihui

1993, 16(2):99-102.

[Abstract](699) [HTML](0) [PDF 253.09 K](1027)

Abstract:
In this paper,a fractal model about the microstructure of spheroidal-graphite is presented through the research on the surface form and the analysis to microregion. The fractal dimension is calculated and the forming mechanism is also discussed.

18 Mechanical Property of the Bile Duct Inside the Liver

Jiang Jiahuan Yan Ruifang Wang Gongrui

1993, 16(2):103-106.

[Abstract](522) [HTML](0) [PDF 222.99 K](915)

Abstract:
根据Strahler分级法确定了肝内胆管的形态级别。在此基础上，剥离了6例狗的肝内三级胆管，对其进行单向拉伸试验，计算分析发现，表征胆管力学特性的dσ/dε、α1和α2的值均随胆管分级数的不同而逐级变化。

19 The Convergence of a 2-Block AOR Method for Large-Scaled Least-Square Problems

Huang Decai

1993, 16(2):107-112.

[Abstract](696) [HTML](0) [PDF 227.52 K](965)

Abstract:
A necessary and sufficient condition and some sufficient conditions concerning the convergence of a 2-block AOR method for large-scaled least-square problems are given. It is shown that, by appropriately selecting parameters, the 2-block AOR method is always convergent and the theorem in [3] is only a corollary of this paper.

20 The Minimal Periodic Solutions to The Subquadratic Second Order Hamiltonian Systems

Zhang Shiqing

1993, 16(2):113-119.

[Abstract](883) [HTML](0) [PDF 276.03 K](1085)

Abstract:
The existence of the minimal periodic solutions to two classes of the nonconvex subquadratic autonomous second order Hamiltonian systems is studied on the basis of the Rabinowitz' s saddle point theorem and the Morse index estimation of its critical points.

21 A Sufficient Condition of Existence of Positive Solutions to Semilinear Elliptic Equations with Critical Sobolev Exponents

He Chuanjiang

1993, 16(2):120-125.

[Abstract](718) [HTML](0) [PDF 204.38 K](872)

Abstract:
设Ω是R∧R中的界区域，n≥3，给出了半线性椭圆方程边值问题{-△u=Q（x）u|u|∧4/（n-2） f(x,u） x∈Ωu=0 x∈ЭΩ正解存在的一个充分条件，推广了文献∧[1-3]的相应结果。

22 A New Spline Boundary Element Method

Yun Zhengqing Tan Bangding Yu Jihui Huang Jian

1993, 16(2):126-132.

[Abstract](966) [HTML](0) [PDF 285.28 K](1002)

Abstract:
This paper introduces a New Spline Boundary Element Method, which neither has corner problems and singular integrals nor involves extreme-conditions of spline function. Three numerical examples are given to show the validity of the method.

23 The Experimental Study of Drying Process of Wet Silkworm Chrysalises

Jin Mingcong Li Yourong Tan Jingwen Ke Ling Yang Li

1993, 16(2):133-136.

[Abstract](655) [HTML](0) [PDF 222.20 K](944)

Abstract:
The drying process of wet silkworm chrysalises, which are the subproducts of the silk production industry, is experimentally studied. The mode of forced convection drying with hot air permeating vertically is adopted. The influence of temperature and velocity of the hot air as well as the thickness of the chrysalises layer in the drying process is analyzed on the basis of the experimental results. An experimental relation of exponental model for wet silkworm chrysalises drying process is obtained.

24 A Treatment to the Isoline for Finite Element Solution to Ferrite-Martensite Microstructure

Xie Xiaojia Liu Tianino

1993, 16(2):137-141.

[Abstract](468) [HTML](0) [PDF 271.01 K](1010)

Abstract:
The numerical solution of sample point stress field in finite element network of ferrite-martensite microstructure under finite deformation has a high-gradient distributive characteristic whose stress gradient between ferrite and martensite crystalline element is very high. If the interpolation method is used in the whole region,the isogram will be seriously smooth so that the original high-gradient sample point stress field will become untrue. This paper presents a new method for drawing isogram of ferrite-martensite microstructiire stress field by interpolating sample points in an element one by one. This method can make the post-treatment of high-gradient discrete stress field in crystalline network approach to a truer condition and solve the problem of arbitrary curve boundary of the deformed two phase steel.

25 Research for Eexperimental System of Differential Isodyne

Qian Zhenming Zhen Xu

1993, 16(2):142-144.

[Abstract](491) [HTML](0) [PDF 197.57 K](1023)

Abstract:
The .experimental system of differential Isodyne developed by authors is represented. The function and structure characteristic of the rotatable real-time loading device which is set in oil tank , the hydraulic scanning device and the device for synchronous movement of incident beam and Isodyne collector are mainly discussed. The fringe pattern of differential Isodyne in various characteristic directions and planes can be real-timely taken, by using this system. This system is able to apply to stress analyses of local effect .composite materials and structures.

Home

Volume 16,Issue 2,1993 Table of Contents

Current Issue

Volume

Issue

Most Read

Most Cited

Most Downloaded