Abstract: Using high speed impacting SHPB apparatus, test rock and ore of four crack types. Under the high speed impect, measure and produce the following:the curves of stress wave, the curves of strain vs time, stress vs time, stress vs strain, stress vs strain vs strain rate and stress vs strain vs the crack type. Compute the dynamic fracture strength and elastic modulus. Compare the dynamic fracture strength and elastic modulus. Compare the mechanical properties of the crack rock and ore in static and dynamic state. Obtain numerical relationship of crack and no crack rock and ore in different mechanical state.
Abstract: Developing microcomputer programs have been regarded as a effective way to expand the applications of numerical methods to rock engineering. This paper proposed a new core data-processing method on microcomputer programing of numerical methods so that core memory can be utilized as much as possible. Next, DYNPAK, a 2d FEM program on dynamic analysis, was improved according to the proposed method on a microcomputer. Finally, a case study was given as a application of the improved DYNPAK.
Abstract: The mechanisms of BF tuyere erosion due to pulverized coal injection (PCI) was analysed and a mathematical model was developed to predict the erosion. The calculated results of the model show that the service life of the tuyere due to PCI erosion has a very close relation with injection rate, characteristics of tuyere materials, geometrical shape of the tuyere and blast velocity etc.
Abstract: A microwave oven of 1400/850 W was used for drying and roasting of pellets.In experiment,the microwave heating rate,drying process and the mineralogical analysis for pellets were investigated. The results show that under microwave radiation the temperature of pellets increases rapidly and the temperature distribution inside the pellets is very uniform compared with the conventional heatly process.The drying rate is also very fast without crack and burst in pellet. The mineralogical phase of the roasted pellets is hematite oxidized from magnetite. The strength of aroasted pellets ranged 170~230kg.
Abstract: The abrasive mechanism of rolled white cast iron with various matrixes are studied by investigating the microstructure, abrasive surface and mechanical properties of specimens.The results show that the abrasive mechanism is different for various matrixes and the B/M composite matrix rolled white iron is one of the best materials against impact abrasion.
Abstract: The effect of nitrogen on the secondary dendrite of primary austenite of Fe-C-Si and Fe-C-Si-Mn grey cast irons was studied through unidirectional solidification. The distribution of nitrogen in solid and liquid phases of the alloys during the growth process of the primary austenite was determined, and the acting mechanism of nitrogen on secondary dendrite of primary austenite was discussed.
Abstract: A sample of middle carbon steel coated with Fe40Ni36Cr2SiCr2Si8B14 alloy was glazed by 10kW continuous CO2 laser. After laser glazing the structures of specimens was studied and examined by SEM, TEM and EDP.Its shown that a amorphous structrure has been produced not ouly at the zone of glazing oneway trip but also at the the glazing overlap. Because of the loss of nonmetallic elements, the microcrystallins exist in company with the amorphous structure.
Abstract: Effect of polyethylene on low pressure diamond growth from the vapour phase was studied. It was found that diamond nucleation on polyethylene coated, un-polished single crystal silicon substrate was greatly enhanced. The mechanism of the observed enhancement and a new concept of the super-saturation of carbonaceous radicales with the SP3 hybridstructure which enhance the nucleation of diamond film have been proposed.
Abstract: Special emphasis of this paper is laid on the measure methods of the temperature field and the mass field of the atomization cone during the spray forming. The temperature field and the mass field of pure aluminum and 6-6-3 copper alloy were measured.The charcteristics of these fields are discussed.
Abstract: In this paper, how to use membership function to describe the non-uniformity of carbides in alloy tool steels are studied.A method for carbide grading has been proposed and tested by a calculation experiment.
Abstract: The experimental steels were hot-rolled by Gleeble-1500 hot-simulated testing machine, The effects of Si,Mn, final rolling temperature, after-rolled cooling rate and rolling deformation on the formation of dual-phase microstructure and property of experimental steels were studied.As a result, the experimental steels have good stability of formation of dual-phase microstructure within the range of experimental hot-rolling parameters, then the properties are also stable.
Abstract: This paper has investigated the recrystallization temperatures and structures of interstitial-free (IF) steels with different microalloying elements (MAE) contents, and the formulas between MAE contents and interstitial atoms carbon and nitrogen, which is very useful for practical production, are obtained. Emphasis to discuss the effects of composition and processing parameters on the properties of IF steel. At last, appropriate processing conditions are given.
Abstract: The purpose of this paper is to show investigations on the dynamics and the deformation of special-shaped wire drawing with roller dies,researchs for proper groove design and development of the roller dies for practical use.
Abstract: Central bursting, one of defects can occur in steel wire during drawing. This article analyses the cause of central bursting, and provides method for preventing occurrence of central bursting. Criterion for central bursting can guide practical production.
Abstract: The method to estimate distributing parameters of gear fatigue life under constant stress level, the method to estimate gears strength distribution of various reliability under constant life and the method to sufficiently use the information from the tests are studied.
Abstract: This paper introduces a method of welding seam tracking when arc-welding robot is applied to welding of shape "V" or angle connection. By processing the current of welding with a way of digital signal processing,the feature signal which reflects the position of welding seam is abstracted. And then transmitted to the robot controler in order to trace the seam.
Abstract: The strategy of solving problem based on heating treating carburizing is studied in this paper. In order to advoid a one sided view or the system, multi-blackboard system used as the strategy of solving problem, no-generally recognized problem of the carburizing is argued by experts. Then system chooses the best conclusion. The theoretical framework of argument is builded based on propositional knowledge. From the framwork, several debate algorithms are designed according to different strategies. The results of the simulation prove the method is feasible.
Abstract: In this paper, the principle of intelligent following system with integration implemented by a microcomputer is discussed. The program block scheme are give. The result of real-time control have been shown:Its speed following error is far less than following system for digital PI,PID and least-tact rippless.Simultaneous, fast trace of the system is obviously enhanced.
Abstract: The concepts of the 2-decomposition and decomposition tree of a directed fundamental cutset matrix Qf are introduced. The necessary and sufficient conditions for realizibility of Qf and the uniqueness of realized graph G in directed 2-isomorphic sense are deduced.The problem, how to find a 2-decomposition of Qf, is solved by hypergraph theory. The principle and algorithm for directly realzing Qf by decomposition method are presented. The principle is intuitive. Its computational complexity is O(v2l2), where v and l are the numbers of rows and columns of the tree-path submatrix Qfp of Qf, respectively.
Abstract: Effects of the tip end thickness of ZrO2(MgO) tube and the amount of reference electrode addition on the response time were investigated in this paper. It is concluded that the optimized parameters for tip thickness of ZrO2 (MgO) tube and the amount of reference electrode are 0.60~0.80mm and 40~60mg respectively. The thermal equilibrium of response process for oxygen probe using "Two TC Method" was also investigated. The results show that the heat transfer in the oxygen galvanic cell is the limitting-step in the response process and the peak appeared in the EMF curve is resulted from the thermal equilibrium in the oxygen galvanic cell.
Abstract: This paper studies the general solutions of nonhomogeneous linear differential equations of third-order with constant coefficients, where the nonhomogeneous member is any continuous function.
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
