Table of Content

30 June 1996, Volume 14 Issue 2

Previous Issue    Next Issue

Articles

MOMENT EXCITATION ON STUDIES OF STRUCTURE-BORNE SOUND

QIU SHUYE, JIANG JIANZHONG, B M GIBBS

1996, 14(2):  127-135. 

Asbtract ( 311 )   PDF (585KB) ( 59 )  

Related Articles | Metrics

A prototype moment actuator is introduced. It consists of two parallel rods of giant magnetostrictive material. Some design considerations both on acoustics and magnetics are presented. Magnetic biases for three prototypes with parallel and series magnetic paths, respectively, are examined in order to optimize the design of the moment actuator.

THE NUMERICAL COMPUTATION OF CYLINDRICAL FUNCTIONS FOR FRACTIONAL ORDERS AND COMPLEX ARGUMENTS

WANG XILIANG, FENG YONGCHENG, SHEN LIYIN, QING XIANMING

1996, 14(2):  136-140. 

Asbtract ( 320 )   PDF (340KB) ( 82 )  

Related Articles | Metrics

A rigorous algorithm for the computation of fractional order cylindrical functions with complex arguments is discussed in the paper. The values of fractional order cylindrical functions are computed by using different formulae according to the argument magnitude,|z|. The algorithm not only is possessed of high accuracy of computation but also is unlimited in complex argument z.programming of the algorithm has been completed.

NONLINEAR TIME-DOMAIN OPTIMIZATION OF TWO-DIMENSIONAL LOSSLESS DIELECTRIC INHOMOGENEITY PROFILE RECONSTRUCTION

Yu WENHUA, PENG ZHONGQIU, REN LANG

1996, 14(2):  141-148. 

Asbtract ( 348 )   PDF (481KB) ( 81 )  

Related Articles | Metrics

The Born iterative method is used to solve the nonlinear inverse scattering problem for two-dimensional dielectric inhomogeneity using time-domain data; three order difference regularization is applied to improve the inversion process; and a general selecting regularization parameter is developed.

THE AREA EFFECT OF FRACTAL FIGURE AND THE RESEARCH ON THE FRACTAL DIMENSION OF FRACTURES

HE ZONGYAN

1996, 14(2):  149-157. 

Asbtract ( 316 )   PDF (573KB) ( 66 )  

Related Articles | Metrics

The authors advanced a new conception the area effect of fractal figures and deduced formulae for the fractal dimensions of three kinds of figures. Because of this effect, some false dimensions may be obtained in the slit island method for measuring material's toughness. So a new method without area effect is proposed.

SOLID PARTICLE EROSION OF CaLa₂S₄

GAO HuA, SUN QlQING, J E FIELD

1996, 14(2):  158-166. 

Asbtract ( 385 )   PDF (1045KB) ( 71 )  

Related Articles | Metrics

Solid particle erosion of the CaLa₂S₄ infra-red transmitting material has been studied; it includes crack initiation and propagation, flake formation and oscillation as well as the effect of solid velocity (from 22 to 180m·s^-1) on crater morphology and erosion rate. Theoretical analysis has been carried out upon (1) plasticity in the contact zone, and (2) the striation mark on the lateral crack surface. And by using a membrane free vibration model, the widths of striation mark have been estimated.

AN ADAPTIVE DEMODULATION METHOD FOR FSK SIGNALS

Hu AlQUN, SU JIE

1996, 14(2):  167-172. 

Asbtract ( 353 )   PDF (369KB) ( 134 )  

Related Articles | Metrics

This paper presents a new method for demodulating the frequency shift Keying (FSK) signals, the adaptive demodulation (ADEM) method. The commonly used least mean square (LMS) error adaptive filtering algorithm is employed for studying the demodulating procedure and the performance of the ADEM scheme. It is indicated by simulation experiments that the ADEM has many advantages over conventional ones, such as the powerful anti-noise ability,the small transfer delay, and the convenient implementation with DSP technology. The idea and Principle of the ADEM can also be applied to other modulation modes.

CONFIDENCE INTERVAL ESTIMATION FOR THE LCCATION PARAMETER OF NORMAL DISTRIBUTION FROM INCOMPLETE DATA

ZHU HONG, LU SHU

1996, 14(2):  173-178. 

Asbtract ( 433 )   PDF (387KB) ( 95 )  

Related Articles | Metrics

A method of confidence interval estimation for the location parameter of normal distribution from incomplete data is given. The result applies to the observed data where there may be outliers.

APPLICATION OF FUZZY THEORY TO THE STUDY OF COMPOSITE factors influencing properties of ARALL analysed by multi-criteria of fuzzy theory

ZHONG WEIHONG, OHEN OHANGQI, ZHENG RUIQI, LI HONGYUN, HU HONGJUN, QIANG WEI, WANG YUYING

1996, 14(2):  179-185. 

Asbtract ( 323 )   PDF (413KB) ( 61 )  

Related Articles | Metrics

The fuzzy theory is applied to deal with composites in this paper. The multi-factor relation figure and fuzzy matrix influencing the properties of the super-hybrid composite ARALL are presented. By using the matrix operation of the fuzzy theory, the multi-criteria matrix is obtained. Through the two-grade-decision method, the degree of influences on the properties of ARALL by the factors, such as the residual stress, adhesive property and content of the adhesive,is analysed. The result shows that the state of the residual stress is the chief factor, followed by the adhesive property and the content. This paper offers a new method to the raw materials choice for the composite and its design, and both the result and the method of the paper are of significance to the study of composites.

THE MAXIMUM LATENESS OF THE JOBS WITH DIFFERENT RELEASING TIMES AND PROCESSED IN BATCHES

SUN SHIJIE

1996, 14(2):  186-190. 

Asbtract ( 352 )   PDF (360KB) ( 73 )  

Related Articles | Metrics

Posner studied the total weighted completion times of the jobs with different releasing times and processed in batches, and obtained good results.This Paper considered the maximum lateness of the jobs with different releasing times and processed in batches too. We not only obtained the results similar to those of Posner for our problem under the same condition, but we also considered more models than Posner. For all these models, we gave the optimal schedule, or changed it into a problem which had been well studied.

THE ACCELERA TED WEAR TEST AND RELIABILITY RESEARCH OF THRUST SLIDING BEARING

ZHANG ZUMING

1996, 14(2):  191-198. 

Asbtract ( 318 )   PDF (450KB) ( 82 )  

Related Articles | Metrics

This paper focused on the difficult points existing in the reliability analysis of the machine elements wear. An on-line measuring rig used in the accelerated wear test of the thrush sliding bearing was developed. The main experimental research accomplishments on the wear process of the thrust sliding bearing were reported in the paper. Based on precise measurement, a new theory and method for the reliability calculation of machine elements wear were proposed.

A STUDY ON TEMPERATURE DISTRIBUTION IN WORKPIECE SURFACE LAYER DURING CREEP FEED GRINDING BY COMPUTER SIMULATION TECHNIQUE

XU HONGJUN, XU XIPENG, XU HONGCHANG, ZHANG YOUZHEN

1996, 14(2):  199-207. 

Asbtract ( 298 )   PDF (623KB) ( 57 )  

Related Articles | Metrics

Creep feed grinding has a vast reservoir of potentialities itself.However since mechanism researches fall behind the production application, its potentialities have not been fully developed. For instance in the grinding circle at home and abroad, the creep feed grinding burn restricting both machining quality and efficiency has been universally considered as one of the most elusive and troublesome problems up to now. In this paper, on the basis of deepgoing researches on grinding heat, the heat transfer process of the contact zone and the unstable-state temperature field in the workpiece surface layer during creep feed grinding,a simulation mathematical model which can be used to calculate the time-course of temperature field distortion in the workpiece surface layer has been structured,and on these grounds, the computer simulation studies of the workpiece burn process during creep feed grinding have been completed. The simulation results accord well with the practice of the burn process during creep feed grinding. The results in this paper take the lead in explaining the heat mechanism of burn course during creep feed grinding, showing that the creep feed grinding burn is a typical slow changing course and has obvious premonition characteristics. Therefore it can be predicted and monitored. This creative work can be regarded as an important contribution to the basic theory of grinding.

MICROCOMPUTER DETECTION AND FUZZY CONTROL OF POLISHING TECHNOLOGICAL PARAMETERS

LIU MINGYUAN, JI CHUNRONG, FANG JIANHONG, YANG LINSEN

1996, 14(2):  208-214. 

Asbtract ( 341 )   PDF (409KB) ( 58 )  

Related Articles | Metrics

The research work of realizing computer control on lens polishing lathe JP12.6 is introduced. It includes the realization of the system hardware and the method of fuzzy control in the Polishing process. The experiment shows that computer fuzzy control, compared with the original manual control, not only has high productivity, but also has stable Polishing quality.

A METHOD TRANSFORMING THE SEMI-INFINITE DOMAIN OF ARBITRARY SHAPE CURVE BOUNDARY INTO THE ONE OF STRAIGHT BOUNDARY LINE

XU LIZHONG

1996, 14(2):  215-218. 

Asbtract ( 388 )   PDF (226KB) ( 82 )  

Related Articles | Metrics

In this paper, an analytical method conformally transforming the semi-infinite domain of an arbitrary shape curve boundary into the one of a straight boundary line is given. By means of the calculative examples, it is proved that by making use of this method, the mapping accuracy is high and the calculation is simple. Thus the paper lays a foundation for the calculation of the stress and deflection of the tooth-shape machine elements which are commonly used in engineering.

THE CURIE TEMPERATURE OF FERROMAGNETIC FILMS

WU XUEYUAN, GU SHIWEI, LI WEISHENG

1996, 14(2):  219-222. 

Asbtract ( 341 )   PDF (245KB) ( 64 )  

Related Articles | Metrics

The thickness dependence of the Curie temperature for the ultra-thin ferromagnetic films ranging in thickness from 4 to 7 monolayers has been calculated by considering the effects of the bound condition on the state and configuration of the electron and consequently on the exchange couplings between spins. The results show that the Curie temperature decreases with the reduction of the film's thickness. This confirms the general theoretical expectation from the microscopic point of view and explains the recent experimental results.

THE SURFACE INTEGRAL TO SOLVE AXISYMMETRIC DRAWING THROUGH HYPERBOLIC DIE

ZHAO DEWEN, WANG GUODONG, ZHONG JUN, DONG XIJAN

1996, 14(2):  223-228. 

Asbtract ( 416 )   PDF (329KB) ( 83 )  

Related Articles | Metrics

A kinematically admissible velocity field for axisymmetric bar drawing through a hyperbolic die is established, and with the surface integral determining the friction power,and the upper limit function integral determining the internal deformation power, an upper bound analytical solution to the field is obtained.

FSS SUBREFLECTOR ANTENNA WITH SMALL RCS

FENG LIN, DENG SHUHUI, RUAN YINGZHENG, HU YULAN

1996, 14(2):  229-232. 

Asbtract ( 451 )   PDF (280KB) ( 66 )  

Related Articles | Metrics

A Cassegrain antenna with frequency selective subreflector is introduced, and the measured radiation Patterns and rsdar cross section (RCS) of the antenna are given. In comparison with ordinary metallic subreflector, this antenna can obtain similar radiation pattern and about 20dB of ROS redaction.This technique can be applied to ordinary dual reflector antonnas by simply changing the subreflector into FSS.

MM-BAND DUAL-POLARIZED NETWORK

YAO TEMIAO, QI LINGFEI, MAO JUNJIE

1996, 14(2):  233-238. 

Asbtract ( 581 )   PDF (301KB) ( 61 )  

Related Articles | Metrics

Two mm-band dual-polarizers of excellent properties are discussed in this paper; various circuits are composed of them; some excellent properties (VSWR, polarized isolation, ellipticity, etc) are obtained from testing results.

CASE FORM CHECKED WITH UCT

DUAN FANGYONG, QU WANLI, HUANG ZAILU

1996, 14(2):  239-242. 

Asbtract ( 292 )   PDF (249KB) ( 60 )  

Related Articles | Metrics

The method of checking the case form by processing the log data go-ten with the ultrasmall cement-bond quality testing tool (UCT) is presented in this paper. The method is proved to be effective by theoretical analysis and the process effect of the real log data.

THE STATIC INDUCTION DEVICES WITH COMPLEX STRUCTURE

S Y LI, S LIU R, X LIU, J H YANG

1996, 14(2):  243-247. 

Asbtract ( 338 )   PDF (769KB) ( 74 )  

Related Articles | Metrics

A complex structure (C-S) which can be used in fabricating the Static Induction Devices (SID)is proposed and designed. This structural devices exhibit typical I-V characteristics and electrical performance, which are the same as those for the surface-gate and buried-gate types of SID. The experiment results indicate that C-S may be adopted as one of basic structures of SID. A prominent merit of C-S is that only ordinary planar technology is used to fabricate the SID.

PRESSURES OVER THE MELTS OF Hg_1-xCd_xTe DETERMINED BY DEW POINT MEASUREMENT

SANG WENBIN, YU MEIYUN, WU WENHAI

1996, 14(2):  248-252. 

Asbtract ( 392 )   PDF (327KB) ( 65 )  

Related Articles | Metrics

Dew point measurement was first used to determine the pressures over the melts of HgCdTe at different temperatures. The results obtained by this method are compared with the data reported by different measurement methods, and the cause of the difference is discussed.