Abstract: The computer aided underground mining design and solid modelling system 3DMGS is developed under AutoCAD for Windows. The computer aided design and plot-ting tools are developed according to the mining design standards, the database of the shafts and drafts is built in the system, and the designed objects can be identified and their geomtric parameters can be recorded automatically to the database from the design map. By making use of AME (AutoCAD Modelling Extention), the visual solid modelling system of shafts and drafts structure engineering is developed. With the application of 3DMS, the efficiency and quality of design work can get improved greatly.
Abstract: The computer aided mine geology plotting software system MGS is devel oped by making use of ADS(AutoCAD Development System). The AutoCAD is taken as supporting system, the geologic data bases are built and managemented by use of ASF/ASI technique, and a group of tools is developed to aid geology plotting. By the support of the data bases and aid tools, MGS can delimitate orebodies, calculate grade, make and cut geology maps.
Abstract: Presents the dynamic characteristic analysis of YZ-55A Blast-hole Drill's structure by using SAP5P program. The result shows that the reasonable working rotation speed range should be between 80 and 150r/min. Based on the load spectrum of YA-55 Blast-hole, the dynamic stress calculation on YZ-55A is carried out by introducing adjusting coefficient, the structure's vibration modes and strees-time histories are are presented.
Abstract: The mushroom cloud forming in a very short time after blasting and the overflwing gases from the heap that emited very slowly from the heap made up the amount of the explosive gases. According to their movement characterstics, the mushroom cloud was taken as the souce of instantaneous volume and the overflowing gases from the heap was taken as the irregular volume, their diffusion pattern is selected as the pattern of smoke volume integral. On the basis of consideration, the pollution evaluation pattern of an open-pit was established by simplifing the pattern and amending the diffu-sion coefficient. A reltively accurate pollution prediction on explosive gases in Dayie Iron Mine was carried out.
Abstract: TEM in situ tensile tests of 310 stainless steel show that a dislocation free zone (DFZ) forms if the displacement keeps constant after dislocations are emitted from a crack tip. The elastic DFZ is gradually thinned and the stress in the DFZ will reach the cohesive strength, resulting in nucleation of nanocracks in it and their bluntness into voids. If continuously tensioning, the inhomogeneously thinning ahead of the crack tip, initiat-ing and connecting of microcracks or microvoids will be observed rather than a DFZ, nanocracks' initiation and bluntness into voids. The inverse pile-up ahead of a loaded crack tip can move back to the crack tip when unloading.
Abstract: A mathematical model of the gas-solid flow and heat transfer in blowpipe of BF oxy-coal injection has been developed by the multi-flow model and turbulence model. Then the velocity and temperature of both gas and pulverized coal as well as its concentration have been calculated in industrial scale blowpipe under different injection conditions. The theoretical predictions are in qualitative agreement with experiments.
Abstract: Using 0.6-scale water modelling based on Fr-We number similitude criteria, the influences of the submerged entry nozzle configuration and operating practices on the level fluctuation in the mold which caused surface defects and mold power catching, were studied. It was found that the level flunction was resulted from gas injection, impact-ing of the stream and standing wave. The level turblence raises with the incresing of the gas injection, however the casting rate, immersion depth and jet angel of SEN have a dual influenc on the level fluctuation.
Abstract: Several parameters affecting slag splashing in LD converter have been discussed. Using paraffin and starch model, a simulated test about 30t converter has been made in laboratory and the modified Froude number was chosen as the main similar basis of the system. It was results that the optimized slag splashing parameters was obtained through data treatment. The nitrogen gas flow rate is about 8 500m3/h, the splashing time is of 3 min, and the lance height is of 0.8m. It is necessary to add MgO or carbon into the slag to adjusting slag composition. Also, it is difficult for the splashed slag condensing on the line when the slag temperature is much higher.
Abstract: From the viewpoints of coexistence theory of the slag structure, the investi-gation on the structural units of MnO-SiO2 system and the chemical reactions between them has been carried out. The relationships between the physical properties of the slag and the mass action concentrations of its have been set up at certain temperature and slag composition range, which based on the thermodynamic data of the chemical reactions between the units and the method of linear regression. The calculated data from the model are in good agreement with the measured results. These calculated values are more accu-rate and systematic than those from other expirical and semi-expirical formulas used at present.
Abstract: An novel approach has been proposed for treating solid ferrous scrap with sulphide matte by blowing the gas with a controlled low oxygen pressure to promote the removal of copper. It has been proved by comparison of the result of the experiment by blowing argon at 950℃ with those of the static experiments that argon stirring can remark-ably increase the rate of copper removal at the initial stage of the treatment, for the matte of 70% FeS and 30% (mass fraction).
Abstract: Kinetical model of calcium ferrite formation at initial stage of reaction in CaO-Fe2O3 mixed bed was obtained by using terms of theory as follows: 1-k1(1-k2BRv)2/3-k2(1+k1BRv)2/3=(2k1Mf/ρfrf2)·DcΔCt.br/>其中k1=(ρf-ρcf)/(ρf-ρc),k2=(ρcf-ρc)/(ρf-ρc),B=1+Mcρfm/Mfρc. The results calculated by this model is identical very well with the experimental data, and the interdif-fusion coefficients of CaO in monocalcium ferrite were determined as 4.34×10-9cm2/s and 2.32×10-8cm2/s respectively at 1160 and 1190℃.
Abstract: A mathematical model of kinetics of carbide layer formed on the surface of steel in fused system was set up with the theory of non-stable diffusion mass transfer and regular solution sub-lattice. This model was analyzed and testified by the experiments in which the VC layers were formed on four kinds of steels as steel 45, 4Cr5Mo-SiV1, T10, and Crl2MoV immersed in the V2O5-Na2O-B2O5 fused system with the reducing agent of silicon. The results showed that there was a good agreement between the model and the experimental results; the growth speed of carbide layer depended on the factors of carbon activity in substrate, treatment temperature, kinds of carbides and its structure.
Abstract: The effect of the solidification conditions on the microstructures was studied during partial remelting of AlSi7Mg alloy with the help of an electrical pipe-type furnace. The results show that the eutectic is remelted above all and α phases are gradually evolved into spheroidal shape, if the AlSi7Mg alloys stirred strongly by rotating electro-magnetic field during the first solidification are heated again to 589℃ or 597℃ and have been held for a short time(for example, 5~10 min), and moreover, the higher the holding temperature, the faster the eutectic remelting process and α phase's evolution are. In contrast, even though the AlSi_7 Mg alloy's samples non-stirred with fine dendritic microstructures ate heated to the same temperatures as those stirred by rotating electromagnetic field and have been held for 60 min, it is not possible to change all the dendritic α phases to speroidal α phase.
Abstract: The microstructural evolution during partial remelting of dendritic AlSi Mg alloys was studied with the help of an electrical furnace. The results show that it is diffi-cult to change all the primary α dendrites into the spheroidal α phases, when the dendritic samples of AlSi7Mg alloy are remelted under 589 or (597±1)℃ and held on this condition for 5 to 120 min. The results also show that the samples remelted can be deformed under the heavy force, if the holding time is longer under higher temperature.
Abstract: The mechanism of inoculation in the case of suspension casting process has been studied through solidification kinetics. The effect of suspension casting process on temperature field, solidification rate, temperature gap of crystallization, effective distribu tion coefficient of solute and nucleation frequency during solidification process in steel ingot were discussed on the base of experiments. It has been found that the suspension casting process can increase both cooling rate and solidification rate of steel ingot, improve the temperature field and solute distribution, narrow the temperature gap of crystal-lication, and increase the nucleation frequency. Thus, the solidification time can be shorten, the solute can be well distributied, the shrinkage porosity can be reduced and the grain of crystallization can be fined.
Abstract: The softening rates of Fe-30%Ni alloy containing boron after 10% and 40% deformation at 1000℃ have been measured by a method of interrupted compression, the recrystallization process has also been evaluated. The moving velocity of the boundary of new recrystallizing grain which was growing into the deformed grains has been calculat-ed semi-quantitatively. By means of PTA technique, the abnormal segregation phenomenon on the moving boundary during recrystallization and the influence of pre-deformation have been investigated and the amount of B segregation on moving grain boundaries has been measured. Results indicate that the abnormal segregation of boundaries, when the new grains are growing, is concerned with the pre-deformation and the moving velocity of the bourdaries. This phenomenon is discussed by the grain boundary widening mechanism.
Abstract: A new quenching-tempering technology system is gotten, in which the quenching temperature is about 910~920℃ and the tempering temperature is about 550~580℃. With using this technology, the mechanical properties of the 590 MPa high strength thick plate are better satisfaction for the using demand. The new technology system is available for the steel plate of different composition.
Abstract: The microstructures of phase transformation by using quntitative metallogra phy was studied. On the basis of analyzing the effects on the microstructures of phase transformation the model of transformation kinetics X=1-exp(-0.642t0.086), and the model of ferrite grain size Dα=5.7×Dγ0.46×Cr-0.26 are constructed and obtained.
Abstract: The rare-earth conversion film forming technology for aluminum alloy was taken as an aftertreatment method of anodizing. The results of several experiments showed that the corrosion resistance of film is increased evidently aftertreatment by rare-earth salts. The sealing action to porous anodizing film is provided by cerium salt. The effectiveness of the sealing can compare with the normal temperature sealing.
Abstract: Applying self-tuning fuzzy control on USTB(University of Science and Technogoly Beijing) double thumb hand, adjusting fuzzy control parameters and control rules, fast respond time and no overshooting control of grasp force is obtained. Adopting grade control, an unkown mass object is grasped stably. Experimental results confirm that self-tuning fuzzy control has better effect than ordinary fuzzy control.
Abstract: A slip sensing method for multi-fingered robot hand is proposed which is realized by detecting the changes of force sensors on the robot hand. Stable grasping of an object based on slip sensing can be obtained by combining the slip sensing algorithm with the force control algorithm and using the idea of multi-level fuzzy control.
Abstract: First, on the basis of the product device hazard level rating, this paper presents the new concepts and relevant properties of Fuzzy language field and Fuzzy language value structure, sets the language field of hazard level as a standard language field, and all the factor language fields affecting hazard level are discussed in this standa rd language field so the description of the states of fire-hazardous level etc. transits to that of hazard level. Next, it presents the Fuzzy synthesize integrated algorithm, and forms a inte-gration of Fuzzy set theory, Fuzzy synthesis evaluation, Fuzzy clustering analysis, Fuzzy logic, Fuzzy linguistics, Fuzzy statistics etc. Then, it develops a software system of comput-er-assisted safe evaluation. Last, this software system is verified effectively in the appliction of many chemical industy instances.
Abstract: The coupling models for the thickness-crown objects is established. A Dynamic Matrix Controller based on the TH neural networks is given with the conver-gence property. The computer simulations with the AGC-ASC decoupled neural networks predictive control system is complemented and it shows that the stable states of neural networks are reached with on more that one μs, this has not only satisfied the fast prop-erty of rolling process, but also obtained a higher control index.
Abstract: The concepts of stability radii of 2-dimensional (2D) Chua's circuit are introduced. One Chua's circiut with a limit cycle was stimulated via computer and corre-sponding stability radii were calculated. The existence and uniqueness of the solution of 2D Chua's circuit are pointed out.
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
