Abstract: During the analysis on the seepage field of fractured rock mass by using the equivalent continuum model, the coefficients of permeability obtained from the pump-in test and the field survey of rock mass structural faces are compared synthetically. Then the modified permeability tensor that can reflect the intrinsic geological environment elements is proposed. Finally, the method is applied to the seepage analysis of open-pit slope fractured rock mass successfully.
Abstract: A method was proposed for assessing the stability of rock slope, of which the knowledge about the stability of rock slopes is extracted from data cases of rock slopes and the integrated intelligent system is built for assessment. The system can be used to predict and assess the stability of any rock slope with the information measured from the rock slope.
Abstract: A prediction method of strata movement in underground metal mines is put forward in which the artificial neural network is applied, and selected factors influencing strata movement are dealt with by the fuzzy ma-thematic method. The results show that there is a strong nonlinear linking between the factors and strata movement angle, and the numerical value of movement angle has much in connection with the factors. It is proved that the scope of strata and surface movement due to mining can be predicted in theory.
Abstract: Based on the measured activities, the phase diagrams and the annexation principle, the calculating models of mass action concentrations for Ag-Bi and Ag-Bi-In melts have been formulated. The calculated results agree with practice and obey the mass action law, showing that the models formulated can reflect the structural characteristics of both melts. Meanwhile, it confirms that annexation principle is applicable to the Ag-Bi-In metallic melts. The melts involving eutectic which give rise to phase separation, and in which activities exhibit positive deviation from Raoult's law is the basic cause of melts transforming from homogeneous to heterogeneous ones.
Abstract: According to the difference of bearing structures between railway and highway under the dynamics key properties of the dynamic loading were analyzed by LUSAS FEM. The curves of displacement on the vertical direction and stress versus dynamic time as well as the relationship between eigenvalues and dynamics frequency about the railway and highway were obtained. The hurtful frequency and hurtful dynamic time of dynamic loading were acquired from analytic results. Combined with a in-situ engineering case of a soil-masses slope, located in Shandong province on No.205 national highway, a numerical model under the two dynamic loading was built by using FLAG. Four different loading conditions worked on the unstable mechanism of soil slope were discussed respectively.
Abstract: According to the characteristics of anti-sliding piles setup in the soil slope, Winkler model and Euler-Bernoulli beam theory, the deflection expression of the piles was deduced and it was sorted out as a function of MCubic parabolicM. The axial force and deflection acting on the piles after the soil slope achieved stability, as well as the variability of anti-sliding moment and shear force on the piles in different elements with the number of computing steps, were analysed based on this function and the combinated of computer simulation (FLAC) with the practical engineering of GYP soil slope on No.205 national highway in Shandong province.
Abstract: Dyeing wastewater treatment with activated carbon fiber as an electrode were studied. The effects of electrode materials, voltage, electrolysis time and electrolyte on dyeing wastewater treatment with the electrochemical method were investigated. The result shows that the decolouring rate can reach above 96.1%, and the ratio of removing COD is 56.78% under the condition of ACF as a cathode, ACF+stainless steel material as an anode, the-voltage being 15 V, the electrolysis time being 30 min, the amount of NaCl as electrolyte being 5 kg/t. After electrolysis, adding a little of CaO in the wastewater can solve the problem of recolouring. It is proved that ACF is a type of catalyzing electrode material.
Abstract: By using of electrolytic pure iron, the specimen containing different heterogeneous nucleus and contents were made in an Mo wire furnace. The DTA method was employed to measure the undercooling of liquid iron during solidification. Equations to calculate the change of Gibbs free energy of solid and liquid iron in solidification were reviewed theoretically. Calculations were performed to obtain Gibbs free energy difference between solid and liquid, critical radius of nucleus and the activation energy in solidification.
Abstract: The foaming processes originated from reducing TiO2 and Fe2O3 by carbon in the synthetic slag were investigated under different conditions in laboratroy. The formation and rupture coefficients, average foam life, foam intensity and beginning time of the rupture foaming process were determined by means of experimental results. The influence of temperature, TiO2 added in synthetic slag and TiC content in original slag on these foaming processes were discussed through the foaming parameters. It is found that the secondary foaming phenomena in twice can take place when the original slag contains when more TiC land more TiOz is added.
Abstract: A mathematical model of the velocity field for a regenerate reheating furnace was established with the commercial software CFX. Using the k-ε turbulent model, the influence of nozzles' shape, size and distribution on the velocity field was studied. The results show that the flow pattern in the furnace is greatly different from that of a traditional furnace and is advantageous to the mixing of fuel and air. The shape of the furnace and especially the size and the site of nozzles influence the flow pattern to some extent.
Abstract: Thermal characteristics of the heating furnace using gas as fuel were discussed. Combining the technique of fuzzy control with calorific value feedforward and oxygen concentration feedback, an optimization model for air/fuel ratio was developed and utilized in practice to keep it reasonable. It is proved that the model can effectively control the oxygen concentration of exhaust gas, enhance the quality of product and decrease the fuel consumption.
Abstract: According to the thermodynamics of continuous medium, the dissipation inequation of crack healing is derived from the second law of thermodynamics. An inner variable H is defined which describes the process of crack healing. Based on variable H , the crack healing process can be explained, the evolutionary equation and constitutive equations of the process can be established, and thus it is possible to analyze the process quantitatively.
Abstract: The micro-process of cube texture formation in high purity electronic aluminum foils was investigated by EBSD (Electron Back Scattering Diffraction) technique in StM and the related analysis of crystal orientation. The nucleation and growth behavior of cube orientation grains in the early stage of recrystallization were discussed and analyzed during the annealing of cold rolled aluminum foils. The results show that the nuclei of cube orientation {001}<100> are not frequently observed in the rolled matrix, however, high purity aluminum foils hold strong cube texture after recrystallization. Cube texture formation abides by the mechanism of preferred growth, and the nuclei of cube orientation frequently form in the deformed matrix with S orientation grains {123}<634>.
Abstract: The effect of TiC particles formed by in-situ reactions on the microstructure of spray-formed Al-8.5Fe-l.4V-l.7Si alloys was studied by means of XRD, OM, SEM and TEM. The results show that needle-shaped AlFeSi is suppressed by TiC and TiC particles distributed homogeneously in the alloy matrix.
Abstract: The principle of rapid measurement texture based on an X-ray two-dimensional detector was described. The advantages of the two-dimensional detector were the ability to collect several incomplete pole figures simultaneously and to calculate the orientation distribution function rapidly. It was found that a complete texture in one sample can be measured in a few minutes and the accuracy of the orientation distribution function was not basically affected when the two-dimensional detector was fixed at an appropriate diffraction angle and the sample rotation was reduced reasonably. This is illustrated by an example of interstitial free steel sheets texture measurement. It is believed that the method can be used to develop a technology for online texture measurement of interstitial free steel sheets as well as other metal sheets in industry.
Abstract: Anisotropic NdFeB magnet powders were prepared by crushing a sintered magnet at elevated temperatures. The experimental results show that the coercivity of the magnet powders prepared at higher crush temperatures near or above the ternary eutectic temperature of the NdFeB magnetic alloy, can reach a much higher value than that obtained by room-temperature crush. The influence of crush temperature on coercivity is closely related to the transition of the fracture way from transgranlar to intergranular manner with increasing crush temperature. In a crush process at an elevated temperature, the reduction of cracks in the surface layer and of sharp edges and corners of the magnet powders, and the formation of an Nd-rich phase thin layer more homogeneously distributed on the powder surface should be the reason for the increase in coercivity. The experiments also show that a following annealing treatment of the obtained powders can further improve the coercivity.
Abstract: Polarization curves and electrochemical parameters of four kinds of titanium alloys (TC4,TC11,TA7 and TA12) were measured in six alcohol solutions with the potentiodynamic method. The effects of H2O and Cl- were mainly investigated. It was found that the pitting corrosion resistance of the alloys was somehow improved when the certain amount of H2O was added in the alcohol solutions and greatly decreased by Cl- in the solutions. Cl- would obviously change titanium alloys from a self-passivation state into an active one.
Abstract: The conductivity performance of lithium ferrite oxide for molten carbonate fuel cells was investigated. The results showed that the conductivity of lithium ferrite oxide can be improved by making Li2CO3 excessive slightly in the process of preparing lithium ferrite oxide. At the same temperature, the conductivity of lithium ferrite oxide increases with the increasing of Li:Fe values. However, at the same Li:Fe value, the conductivity of lithium ferrite oxide increases exponentially with the increasing of temperature. It was shown from the SEM analysis that the electrode surface micrographics of lithium ferrite oxide with various Li:Fe values are different.
Abstract: The hot rolling of a steel billet in oval pass and the variations of rolling force and torque are simulated by three-dimensional thermo-mechanical coupled elastoplastic finite element simulation. It is shown that the difference between the velocities of the metal flow along the rolling direction on the surface and in the inner part of the billet results in the concave section at the rolled steel ends. The rolling force, the axial force, rolling torque and radial torque have a similar variation, which is large during the period of the steel billet being engaged with or leaving from the oval-pass and small during the period of the stable rolling.
Abstract: The characteristics of heat transfer were discussed for annealing thermal processes in HPH furnace. A mathematical model was proposed to calculate the annealing curves of rolled coils. The caculated results were compared with experimental data. It is shown that the mathematical model is reasonable and reliable to the heat transfer for annealing thermal processes HPH furnance.
Abstract: A statistical wear model of backup roll was built up based on a large number of measured data. The model is a multiple extremes and high non-linearity semi-theoretic formula whose pattern and magnitude are hardly defined with classical optimization methods because the computation is large and complex. By using the simulated annealing algorithm with memory, the coefficients in the roll wear model are optimized. The calculation results indicate a higher precision for prediction. After the model was applied in a 2800 4-roll mill of Wuhan Iron and Steel (Group) Co, the plate shape had been notably improved.
Abstract: Based on the fuzzy neural networks, a composite control system without any model was proposed which is used to automatic flatness control (AFC) and automatic gauge control (AGC). The simulation result shows that this system has good performances of convergency and resisting disturbances and gains a satisfied control accuracy of the flatness and the gauge.
Abstract: The pressure swing adsorption (PSA) technique to produce high purity oxygen is researched by using a zeolite molecular sieve column and a carbon sieve column. A control system based on PLC is designed to regulate the flow and pressure, as well as to control the solenoid valves, with the advantages of high adaptability and reliability. The technical process of two adsorption stages is selected, the optimum adsorption time of every column is determined and the effect of air displacement on oxygen purity in the carbon molecular sieve column is analyzed. The experimental results show that the highest oxygen purity can be up to 99.5%.
Abstract: Vehicle's steady state cornering performance (oversteer/understeer) has substantial influence on its handling and stability. Main factors affecting this performance are analyzed based on modeling of coach HFF6850 for simulation of the handling dynamics by ADAM. The steady state cornering performance is appraised by scoring of three indicatives, i.e. lateral acceleration at neutral steering point, understeer rate, and roll rate of the vehicle body, and then comprehensive scores are calculated. Suspension and tire parameters are adjusted according to the comprehensive scores to improve the coach's handling performance.
Abstract: A method named EIR Method is introduced, which makes use of corrosion potential, corrosion current and concrete resistivity to assess the corrosion severity of reinforcing steel. It ameliorates the veracity of some standards such as ASTM C 876-91, and has been successfully used to estimate the corrosion severity of reinforcing steel in concrete in a famous building in Beijing.
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
