Abstract: The methods simulating the grounds and support system of the tunnel located in swelling rock masses,which includes FEM and model test,is studied.By using the methods,the law of tunnel grounds and the theory of supports are analysed and discussed.
Abstract: An empirical mining knowledge base which consists of BP modelsand its application to predict major techno-economical indexes for preliminarily selected mining methods is presented.and the process of building the BP models for open stope mining method is described.Studies indicate that using the empirical mining knowledge base,the major technoeconomical indexes of mining methods can be predicted,based on their engineering background.
Abstract: An expert system based on neural network was establised for judging the state of blast furnace.The Back-Propagation network is used as engine of ES.This ES with selflearning function and associative memory function can be learning when the system off line and can save the samples into the knowledge base when the system on line.So the system ability can be developed continuously.
Abstract: The result shows that the rate of bismuth recovery reachs 7.54% by adding pure bismuth to liquid steel under the experimental condition.The evaporation process of trace bismuth is controlled by transport in both the metal boundary layer and the evaporation from the pool surface, in which the transport coefficient K23 is at the order magnitute of 10-2cm/s.The experimental formulas to calculate K23 and bismuth concentration in molten steel have been gained.The effect of covering slag on bismuth evaporation has also been studied.
Abstract: The flow phenomena inside a slab casting mould are studied in detail.The different flow phenomena influenced by the operating parameters are discussed.For these purpose,a software for numerical solution of three-dimensional flow with microcomputer was developed.The new option for the wall function and method of pressure gradient order drop was deduced in the mathematical model.By comparing the results of calculation to that of measuring by LDA,it shows that the software is available,and it can be applied to predict the flow pattern inside the mould.
Abstract: The primary feature of the sectional image of the discharging end about sinter machine was extracted by analysis of the relation between the changing of sinter process and the sectional image.In addition,the method of primary feature extraction was established based on the process mechanism.On the basis of these,the secondary feature was extracted and can quantitatively describe the changing of sinter process in four respects.
Abstract: The triaxial mechanics properties of a resin sand at elevated temperature are revealed through the recently developed trixaial apparatus for moulding sands.The traditional test method is found unreasonable by comparison with the present results;and the new comprehension to the high temperature behavior of moulding sand is given with the modified strength theory.
Abstract: Silicon carbide particulate reinforced composites with ZA22 alloy matrix were fabricated by semisolid metal mixing method.The structure and property of SiCP/ZA22 were studied by compar son with ZA22 alloy.The results showed that most particles distributed on the grain boundary,some of them reacted with martrix alloy and the reaction lay acted as nucleating base of α primary phase,fined the grain structure.The mechanical properties mainly depended on particles distribution and interface strength.The elastic constant of the composite were found higher than that of ZA22 alloy,but the ductility were lower.The composites also have high stability under high temperature.
Abstract: Arc action in plasma torch with large anode nozzle and long arc passage has been researched by means of electromagnetism and hot fluid mechanics.It has been showed that the special phenomenon will emerg when temperature gradient and electric field gradient act on fluid.The results indicate that high temperature effect of arc column strongly prevents cold gas current from getting in,so as to restrain CVD process.Newly emerging colloidal particles deposit progressively on passage wall under the action of heatphoresis.Above mentioned problems can be solved effectively by changing entrance positions of different gases,reducing gradients of temperature and electric field as well as adding radial circular magnetic field.
Abstract: 3-D models of deformation zone of Accu-Roll mill are established.Simulative software of 3-D deformation zone is developed using 3-D solid model method on 486/50 microcomputer,all kinds of sections of deformation zone can be cut at every position of deformation zone.
Abstract: The paper presents the fuzzy plan of the time-cost analysis for network plan which on work in running and debugging on the computer.The calculating indicates that the optimization result of the algorithim makes the ampledecision room to the planner.
Abstract: A concept of global frequency response function(GFRF) has been presented.The MIMO modal parameter identification modal has been established,based on the weighting sum of modal shape squares.The analytical results of artificial example show that the proposed method has the advantages of accuracy,consistency,separating closely-spaced modes and eliminating random noise.This method can be used for experimental modal analysis of large or complicated structure.
Abstract: Based upon GB3480-83,this paper establishes the function relation between pitting area and revolving period of gear,and puts forward the method about applying stochastic time order under middle and low speed and heavy duty.
Abstract: Based on exact numerical calculation of Bessel functions,the frequency equations and the mode functions of usual circular saw blades with the effects of the centrifigual force neglected are exactly solved and calculated respectively,so the exact vibration modes of the saw blades are obtained. In order to examine the correctness of the results,a certain saw blade is analysed by finite element method.The findings by the two methods show a great consistency.Additionally,it is confirmed by computation that the influence of Poisson's ratio of steel on the vibration modes of the saw blades is very small.All the findings in this paper provide a direct use for saw blade design.
Abstract: This paper analyses the process of automatic gauge control/automatic flatness control(AGC-AFC) system,presents the feedback close-loop control model of AGC-AFC complex systems,and decouples AGC-AFC systems.Them Smith predictor is used to compensate the effect of delay link,and the concise PID controller of AGC-AFC are designed.The result of simulation prove the effectiveness of the algorithm.
Abstract: Based on nonlinear factors analysis of static friction,Coulomb friction,viscous friction etc.for a multifingered robot hand,the dynamic control model of a flexion-extension joint is derivied.To overcome the nonlinear effects,the discrete learning control strategy is presented.The convergence theorem is also given.The simulation result shows that it can make finger joint position reach desired position after finite times iteration.
Abstract: In view of the multivariate regression analysis,astepwise regression analysis method with non-negative constraint to solve the ill-posed integral equation is proposed,which is required in NMR technique for the analysis of pore structure.This method is numerically stable,easy to implement with less calculations,and a more continuous distribution f(T1) can be obtained.Two ways to reduce the effect of noise are suggested:Marquardt method and the smooth approach proposed by Hesse.From the results of the computed examples this method works quite well.
Abstract: The solubility of Ca in liquid manganese and the interaction effect of third element were determined in a sealed Mo reaction chamber by vapor pressure method.The relationship between the saturated dissolved amount of Ca in molten manganese and the temperature ranging from 1573K to 1673K obtained can be expressed.The interaction parameters of the third elements on Calcium at 1673K in liquid manganese can be obtained.
Abstract: In this paper the existance of Ce-Carbide and its forming condition have been discussed by means of electrolytic extraction and X-Ray diffraction. The result obtained shows that it can form Ce2C3,if the content of Cerium equals 0.25% and the Carbon reachs 1.22%.
Abstract: The mechanism of the cathode process of B(Ⅲ) on a platinum electrode in molten LiF-NaF-KBF4 at 750℃ has been investigated by means of cyclic voltammetry and convolution technique.It Was found that the electrochemical reduction of B(Ⅲ) to elementary boron is a simple three-electron process involving alloy formation with the platinum electrode.The cathodic process is very close to a reversible process and is diffusion controlled.
Abstract: The factors having effect on the surface temperature distribution of large U-type radiant tube burner are analysised.For the radiant tube with air singly pulled and diffusively combustioned,the application of corebusters can improve the combustion efficiency significently,control the fuel-air ratio Precisely and enhance the heat transfer between the heigh temperature gases and the tube,thus it can ameliorate the temperature distribution.
Monthly, started in 1955 Supervising institution：Ministry of Education Sponsoring Institution：University of Science and Technology Beijing Editorial office：Editorial Department of Chinese Journal of Engineering Publisher：Science Press Chairperson：Ren-shu Yang Editor-in-Chief：Ai-xiang Wu ISSN 2095-9389CN 2095-9389
