Abstract: The transient is opachic and isochromtic tringe patterns are acquired at a blast loading.Two kinds of ways are used to study transient stress field in infinite plate subjected to concentrated blasting load,the different calculation results are contrasted.A new verifying method for judging the orders of two kinds of fringes is devised if stress wave is reflected at the free boundary.
Abstract: Through physical and mathmaterical simulation,the flow patterns in the tundish with a new-born type of flow control device——Preventur Pad were studied. Compared with the typical dams and weirs,preventur pad can return the fluid from the stockel directly to itself,maximize the mean and minimum residence times,increase plug volume and cancel short circulation in the tundish.Especially in high-speed casting, preventur pad+dam+weir has better effect on the removing of inclusions from the tundish. The fluid patterns in the tundish with preventur pad have been proved through mathematical simulation.
Abstract: The characteristics of local phase diagram in WC-(Ni-Fe)pseudo binary system were studied by means of optical microscope,SEM,X-ray diffraction and thermal-analysis.The maximum solubility and the solubility at room temperature of WC in γ phase were also measured.The results show that WC-(Ni-Fe)pseudo binary system is still a typical WC-(Ni-Fe)eutectic phase diagram.The eutectic temperature is 1419℃.The solubility of WC in γ phase varies with temperature.The maximum solubility at eutectic temperature is 11.2% and the solubility at room temperature is 9.01%.
Abstract: he Nanomic composite oxied power of(W,Ni,Fe)system is made in a ultrasionic spray heat-transfer device using rapid mixig method of alkalinous solution of H2WO4,NiCl2 and FeCl2 solution.The phase composition of the composite oxide power and its relation to the flux used are studied by means of X-ray diffraction and(XRD)TEM analysis.The shape characteristics of power particle and the particle range are studied as well.The results show that homogenous composition of composite oxide power can be made by the methods of rapid mixing of the above two solutions and ultrasonic spray heat-transfer methods.When the self-made oxide flux is used,the phase composition of composite oxide power is WO3,NiO.The powder particle range is 15~50nm and the particle shape is near to sphere.
Abstract: The effects of electromagnetic stirring on the primary austenite in the cast iron and as-caststructures of the spring steel was studied.The experiments had shown that the primarily large austenitic dendrites can be fined when stirred by electromagnetic field for a short time and the higher the stirring power,the more sphercal or dedendritic the primary austenite,and that the fluid flow and temperature fluctuation of the melt may be induced by stirring,and accelerate the remelting of the second arm and decrease of the length of the first arm so that the primarily dendritic austenite is changed to spherical shape finally.That the column dendrites of the samples of spring steel can be also fined by the strong electromagnetic stirring and changed into fine equiaxed grains.
Abstract: Microstructure characteristics of Al-24%Si alloy was studied at the condition of isothermal electromagnetic stirring.Experiment was divided two groups:Stirring and no stirring during cooling course.Isothermal temperature is 577℃ with shearing time up to 40 minutes.Results discover that primary silicon crystal fragmentation and agglomeration occurs simultaneously in the course of stirring.The size of primary silicon phase tends to a constant. Spherical phase appears in the microstructure.
Abstract: A mathematical model of axisymmetric compression of semi-solid alloy slurry was described.The model is applicable to conditions where the solid and liquid phases may be contiguous and their deformation behaviors are coupled.The densification of the solid skeleton drives the fluid flow behavior,and the resulting pressure distribution in the liquid affects the densification in the solid and the liquid phase segregation.The model can predict radial distribution of liquid fraction of semi-solid alloy slurry,specimen.
Abstract: The formation mechanism of aluminum borate in the combustion synthesis of Al2O3/B4C composite was proposed.Based on the formation mechanism several approaches taken to eliminate them are discussed.The X-ray analysis and SEM observation of the SHS products at various conditions reveal that the holding at elevated temperature before ignition is conducive to the formation of Al4B2O9.The unconverted B2O3 is the major cause of the formation of Al18B4O33if the reaction proceeds in the SHS mode.The amount of Al18B4O33formed is very sensitive to the excess B2O3 to the stoi-chiometry 4Al+2B2O3+C and influenced by the size of B2O3 powder.The high dispersion of the reactants is helpful in prompting the thermite reaction to consume B2O3 and hence inhibiting the aluminum borate formation.
Abstract: A study about fiber breakage and its affected region was presented.Some results of numerical analysis and experiment were obtained by evaluating a feasible simple model based on crack propagation statistic theory.The cxperiment studied the boron fiber breakage and its affected region in titanium matrix composites.The results indicate stress redistribution and concentration due to broken fibers obviously affect the stress-strain condition of the other neighboring unbroken fibers.Accompanying with cumulative process of fiber breakage,the original crack extend and its affected region (also affected length)successively enlarge.In metal matrix lower volume fraction fiber-reinforced composites,the work hardening of matrices also affect the process of fiber and composites damage.
The fracture of Fe-25Cr-5Al alloy has been studied.Above 1000℃, grains of the alloy grow quickly.When grain size(d)increases to 80 μm,the fracturs mode transited from dimple pattern to quasi-cleavage fracture;d ≥ 100μm,fracture surface appeares cleavage fracture.During thermal cycling treatment process,due to non-equilibrium segregation of chromium to grain boundaries,precpitation of micrometer scale of α'-phases can occur at grain boundaries the formation of σ-phase can result in intergranular fracture.
Abstract: A new synthesizing method of four-bar linkage,in which the coupler curve has the point with five-point contact(Burmester's point),is presented.With this method, the point which is on the expecting straight-line,the direction of the line and one frame point,can be given beforehand.In each condition,infinite kinds of linkages can be obtained for designers.In the article,some synthesizing formulae are derived and a few synthesizing examples are given.The results have proved that the formulae are correct.
Abstract: The main source leading to random parallel waviness across the width on the jobbing sheet surface was found out by means of the latest comprehensive test technology and then took improvement measures and adjustments on the rolling mill.
Abstract: The principle and method of expert system for abnormal conditions judgment of blast furnace was introduced.Because the situation of "bottleneck" is existed in the knowledge acquisition in the coramon expert system,the artificial neutral network is used to judge abnormal conditions of blast furnace.The results of simulation prove that the expert system based on nrutral network is practical,in the application of blast furnace.
Abstract: Speaker-dependent recognition of Chinese isolated words using neural network model is expended.Speech recognition system based on 3-layers BP neural network is established.The voice data of 10 Chinese numbers were tested.The result of recognition is satisfied.
Abstract: White noise,pink noise and sinusoidal wave are recognized by a neural network.Then a single chip microprocessor is employed to adaptively filter them and pulse noise.The experiment results show that the scheme proposed is correct.
Abstract: By using the method of state recognition,a plausibility function which describes the resemblance between the sample and each class can be obtained through distance function.For the marginal samples,a new plausibility function based on two or several groups of evidences can be determined according to plausibility function.This method provides a better framework for modeling the human being's reasoning process. The result proves that the rate of recognition correctness is satisfactory.
Abstract: A new intelligent automation method on the basis of pattern recognition is proposed in situations that no mathematical equations are available to depict complex industrial processes.From information point of view the essence of this method is first to describe a process by use of feature vaeiables,and then establish prdiction model via time series analysis to provide useful information for process optimization.An infrared CCD thermovision system is introduced to fulfill the goal mentioned above and in order to establish the prediction model an algorithm based on neural network is provided as well.
Abstract: Some concepts such as inverse brownian motion,inverse martingle are introduced,and relative properties are investigated.By the method of Lyapunov function, the stochastic stability of backward stochatic differenttiai equation(BSDE)of It? type is studied as follow $\left\{ \begin{array}{l} {\rm{d}}{y_t}=b({y_t},t)dt-\sigma ({y_t},t)d{w_t},t \in[0,T]\\ y(T)=\zeta {\rm{a}}{\rm{.s}} \end{array} \right.$
Abstract: To make full use of process information and analyze the responsibility within different processes in a production line,fuzzy diagnosis theory with two kinds of control charts is proposed.First,two kinds of control charts based on fuzzy judgment are proposed,then fuzzy diagnosis tables with two kinds of control chart are also proposed.
Abstract: For the near zero non-conformity process,the traditional SPC theory should be developed to adapt the new situation.Using the cumulative number of conforming items as a statistic has been proved to be an effective way to research this near zero non-conformity process.On this basis,a complete criteria for statistical control and or abnormality are proposed.
Abstract: Discussed the multivariate cusum,proposed the diagnosis theory with two kinds of cusum chart and compared with the multivariate T2 chart.With a case study as a example is proposed.
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
