Abstract: A new method was presented that adding the dust-adhering bar into the drilling hole in coal seam can decreases the infused water's surface tension and prevents vaporization for improving the infusion effect. The effect of different infustion water methods to humidify coal seam were determined. The awash method and carve wall method were taken to measure the dust-adhering bar's function to prevent vaporization. The test of adding dust-adhering bar into infused water was compared with that of generally water-infusing. The result showed that adding the dust-adhering bar into the drilling hole in coal seam can effectively prevent the infused water from vaporization, and greatly improve the dust fall effect of water infused into coal seam.
Abstract: The macro-qualities of coal have been explained completely. But its micro-qualities need to be studied. The electric charge distribution on the surface of coal was calculated by means of quantum chemistry. The mechanism that polymers are adsorbed on coal surface is analyzed in detail, which successfully explains why anionic polymers are adsorbed by coal surface with negative charge. Because it uneven electron density in distribution, some area of electron density is thinner on the coal surface. So the active group of polymer could be adsorbed on it by means of van der Wauls and hydrogen bond force.
Abstract: In order to study the enhancement effect of magnetic field on desiliconization of industrial supplying water, the comparative experiments were carried out. The experimental results showed that treatment on water before dosing increase the effect of desiliconization and treatment on water after dosing decrease the effect of desiliconization.
Abstract: The development of the carburized bearing steel 20CrZNi4A with 10 t EAF, was introduced. The results show that the finishing product, with w[H]<10-6 and lower inclusion content, was producted by the single Electro ARC Furnace.
Abstract: The influence of EAF dust and coal amounts added into slag as well as temperature on the slag foaming height had been investigated in laboratory. The results show that the maximum slag foaming height increases, with the increase of EAF dust and coal amounts added as well as temperature. The reduction and evaporation rate of ZnO speeds up with the increase of temperature during slag foaming. The evaporation rate of ZnO is more than 97% in 6 min. Pb in slag is less than 0.02% in 3 min. Temperature seems to have no clear affect on the evaporation rate of Pb in slag.
Abstract: The static equilibrium differential equation in casting and rolling zones during high-speed roll casting process is deduced respectively using the slab method. The equation in the casting zone is numerically solved by Runge-Kutta method and that in the rolling zone is analytically solved according to the mixed frictional condition. Conventional roll casting of a roll caster is simulated based on these established models. The validity of these models is verified by the agreements of the calculating results with the experimental. Based on this fact, the virtual simulation of high-speed roll casting is carried out. Comparis on with the conventional roll casting of a roll caster shows that the designed parameters of mechanical properties of the roll caster under the condition of high-speed roll casting should be raised.
Abstract: A TiC/A1-20Si-5Fe composite is fabricated by melt in situ reaction spray forming and effect of in situ TiC particulate on the microstructure of spray-deposited Al-20Si-5Fe alloy is studied. Both theoretical and experimental results have shown that some Al-Si-Fe intermetallic phases with needle-like structure exist in the spray-deposited Al-20Si-5Fe alloy, which is harmful to the tensile properties of the composites. The needlelike intermetallic phases can be entirely absent in the final product after 5%Tic (mass fraction) particulates are in situ formed in spray-deposited Al-20Si-5Fe alloy.
Abstract: Final temperature and controlled cooling process were simulated by Gleeble-1500 type hot simulation experiment machine. The rules that Ar1, and Ar3 Phase transition points of 60Si2MnA steel were effected by final temperature, laying head temperature and controlled cooling rate were studied, the dynamic continuous cooling transformation (CCT) curve of steel 60Si2MnA has been investigated.
Abstract: The thermal stress in SiC/C FGM in steady temperature field was analyzed based on the classical lamination theory and thermo-elastic mechanics. The optimum composition distribution parameters for fabricating SiC/C FGM were obtained through the above analysis. SiC/C FGM F4 and F7 were fabricated successfully by hot pressing. The microstructure was observed by SEM. Thermal shock resistance of SiC/C FGM was repeatedly tested by quenching from 500℃ into water with room temperature. It has been proved that FGM F7, which was fabricated with the optimized parameters, has better thermal shock resistance.
Abstract: α-SiC ceramics and β-SiC ceramics were obtained by hot-pressing through using Al2O3, and Y2O3, as sintering additives. The phase composition and microstructure of the sintered SiC were investigated. α-SiC ceramics were densified based on the liquid phase sintering mechanism, in which YAG was formed in situ by the reaction of Al2O3 and Y2O3. The relatively large grains show that grains grow through solution-reprecipitation and "Core/shell" structure is formed. The phase analysis revealed that the phase transformation ofβ→α in β-SiC ceramics occurred during sintering. The morphology indicated that the rod-like grains were formed in the β-SiC ceramics.
Abstract: The effect of different pouring temperatures on the microstructures of AlSi7Mg alloy has been researched. When the pouring temperature is close to the liquidus temperature of AlSi7Mg alloy, the primary α-Al in the billets of A1Si7Mg alloy solidifies into spherical or nodular grains which are small and distributed homogeneously. In order to obtain non-dendritic semi-solid billets, the appropriate pouring temperature is 615℃. The faster cooling rate,the melt flowing and larger solidification region induced by the near liquidus pouring temperature promotes the formation of spherical or nodular primal α-Al.
Abstract: The first domestic thermo-chemical polishing apparatus is setup. Three φl10 mm in diameter diamond films can be polished simultaneously at 10-3Pa from 750℃ to 100℃, with the polishing rate increasing with increasing temperature. The results of polishing at 980℃ showed that polishing of CVD diamond films is very efficient. Thermo-chemical polishing mechanism is based on the transformation of diamond into graphite and the atomic dissolution of carbon into a hot metal.
Abstract: The key technology—separating theory of the waste material of LOM on industry application is analyzed and discussed. The separation critical angle is defined at the first time. The methods of compartmentalization make use of the separation critical angle are elaborated. After used the separation critical angle, the question of separation waste material would be solved completely.
Abstract: Develop ANN learn-forecast system by employing BP algorithm to forecast the performance of IF steel, test and analyze the system by using data collected from BAO Steel, and compare the precision of forecasted data with that of the multivariant linear regression model. The results show that the relative errors of ANN learn-forecast system on σb,δ1, r and n are all less than 5.0% except that on σ0.2 is 9.0%. It is concluded that this system has a higher forecast precision than the multivariant linear regression model.
Abstract: Regularities of interdiffusion of Al, Ti and Ta for DD402/FGH95 couple during HIP at different temperatures were studied. The up-hill diffusion flux of Al and Ta in single crystal DD402 was found. As a result, a rich zone of γ'phase forming elements and rafted γ'phase were developed in single crystal DD402 close to the bonded interface. The diffusion fluxes and diffusion depths of Al and Ta were calculated. The calculated results were corresponding to those the experiments.
Abstract: The Ti-Ba-Sol precursor was prepared by sol-gel processing. In order to synthesize the nanosize polycrystals, drying and calcining were carried out. The preliminary crystalline size, target value, was determined by XRD-spread method. The samples were divided into three classes by pattern recognition and then the parameters were designed according to the figure. The experimental data showed that the predicted results were correspondent with the experimental ones. Therefore the conclusion could be drawn that pattern recognition did good to overcoming the disadvantage of conventional synthesis, cook-art chemical method.
Abstract: The obvious deformation occurred in shell of Bao Steel 300 tone BOF turned into a serious danger for safety production. A series of studies were carried out for determining the reason of the deformation such as finite element analysis for stress of the shell and creep test, etc. By means of these studies, the strplus-life of the shell was predicted successfully.
Abstract: Based on the principles of structured program design and normalized database design, a database system for the design of extrusion dies was developed. The system includes six design modules for six types of dies (dies for bars, dies for solid shapes, hollow section dies, dies for wall panels, spreading dies, dies with flow guid) and one system maintenance module, is not only the main sources of expert experience and design criteria, but also the supporting layer for the self-learning and self-accumulating in expert system for the design of extrusion dies. As an independent software, the system can accumulate experience and data related to die design, act as design standards manual and accomplish the calculations of certain design parameter and strength conditions of extrusion dies. The system is useful for decreasing designers' workload, improving the accuracy and rationality of die design.
Abstract: The reason why unusual flow signals exist and the main effect of the siguals were investigated in hydraulic systems. It is pointed out that flow signals are also a rich carrier of condition information after the examination of the close relationship between the work condition of hydraulic systems and the flow nals. According to the experimental research on the faults of gear pump, it is practicable and effective using flow signals to monitor the condition of hydraulic systems and to diagnose the faults.
Abstract: Based on the industrial mills, this paper has built a practical shape equation, which reflects the characteristic of shape generation and shape control and meets the demands of shape control in hot strip rolling. Meanwhile, a complete analysis method is given for building the shape equation. According to the comparison between the sample data and calculated results, this model is accurate.
Abstract: One of the method of curbing plate bending in jobbing sheet rolling process was researched. The relationship between plate bending curvature and pass reduction and temperature difference of plate section is analyzed. The optimum value of pass reduction can be decided.The theory has been adopted in practical production and is proved to be correct.
Abstract: A high quality of metel tensile test manage system by computer network is developed. The manage system includes vocational work manage, sample test manage, inquiry, system server. After the test it proved that the system is advanced, reliable and stabilization.
Abstract: Based on optimal region of wheeled mobile platform and the relation between mobility and manipulability of wheeled mobile manipulator, a new optimal criterion for wheeled mobile manipulator's pointpoint motion planning problem was proposed. The criterion includes not only the cost of mobile platform, the cost of manipulator, but also the cost which mobile manipulator takes to go away it's optimal configuration. Finally, the feasibility of the method was proved by simulation.
Abstract: The fuzzy control method is mixed into the genetic algorithm to adjust the probabilities of crossover and mutation. A new improved genetic algorithm named the fuzzy genetic algorithm (FGA) is proposed. Simulation results show that FGA is very efficiency for the quality of the solution is improved and the convergent speed of the solution is accelerated.
Abstract: The method of effective plotting diagram of open-loop systems was studied in two aspects. Firstly, his calculus was efficaciously improved:the common formula of real and imaginary frequency response was advanced that is convenient for manual computation and more convenient for compute programming.Secondly, two criterions are posed for use of quick confirming the forms of diagram:they are the criterion of original asymptote and cross-point on real and imaginary axes.
Abstract: The concisely analyses problems of traditional teaching, interactive distance learning mode based on WWW is constructed. the new distance learning system is developed to apply the system to mining engineering teaching. which contains sub-systems such as Web courses, intelligent test database, discussing areas as well as real-time school-teaching etc, meanwhile. It is propitious to enforcing distance education.
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
