Abstract: Based on the atomicity and molecularity(negative deviation of activities from Raoultian behavior, minimum ΔG and ΔH of mixing at certain composition, abrupt go up of excess stability as well as maximum resistivity at compound formation composition and phase diagrams) the coexistence theory of metallic melts structure involving compound formation has been suggested. According to this theory, calculating models of mass action concentrations for different molten alloys have been deduced. The fact that calculated Ni and Nj with these models are in good agreement with measured ai and aj confirms that the coexistence theory of mentioned melts appropriately reflects the structural reality of these melts.
Abstract: The mathematical model of the smelting reduction two-stage process with the shaft furnace-iron bath can be used for calculating the energy balance for the processes of the coal gasification in the iron bath, smelting scrap, prere-ducing are or pellets in the shaft furnace and smelting redution in the iron bath. The results calculated by the model conform with the results of the pilot plant test of those processes satisfactorily, which shows that the model is very reliable. Mean while, the parameters in the model is discussed in detail and selected reasonably so that the model can be used for calculating the energy balance of the smelting reduction two-stage process with the shaft furnace iron bath.
Abstract: Studied the reaction dynamics of the solution of N2 in the liquid Fe-C-O system, measured the effect of partial preasure of N2, content of O2 and C, temperatures on the solution rate. This reaction was in first order when[O] content is lower; it was second order when[O] content is high; the rate of solution is lowest when the[O] content is very high. The influence[C] content on the mass transport constant of solution is evident. The apparent activation energy at first order is 131.6 kJ/mol, and 122.89 kJ/mol at second order.
Abstract: Insulation riser made of the cenospheres has good insulation effect by using in casting production. The time of solidification of steel liquid in the riser are delayed, Not only the shrink hole, shrink porosity are eliminated but also the feeding efficiency of riser is increased obviously. Raise efficiency and yield of casting technology have increased by (10-20)% and (10-13)% respectively. Metal liquid, source of energy are saved.
Abstract: Theory, apparatus and application of this method are described in this paper. In a laboratory pipe, the air flow rate is measured by this method with a helium tracer. The results are compared with the data got from a standard pitot tube in the same conditions, and the relative error is very small. The above method is also used in Beijing Coking and Chemicals Plant for measuring the inlet coke oven gas flow rate of one large and another medium scale compressors, the systemetic errors of experiment are calculated. It is showed in practice that this tracing method of gas flow rate measurement can be used in the condition which is inavailable for common flow rate measuring instruments. It is disscusscd for further improving the measuring precision.
Abstract: In order to study the variation of Austenite grain, the Ti-treated 16Mn steel was multi-pass deformed in Austenite complete recrystallization region at constant rolling temperature, pass reduction and interval between passes. After multi-pass rolled, the Austenite grain reached a limit size dr. To change deforming conditions will affect the critical amount deformation (Rcrit) required to reach the dr With the increasing of deformation temperature, Rcrit decreased and dr increased; At big pass reduction, Rcrit increased and Dcrit decreased; while the affluence of interval between passes on Rcrit and dr was small. Depending on above mentioned result, a reasonable technical schedule for this steel to be control in Austenite complete recrystallization region is that there must be at least two passes at 950℃ or so and each pass reduction is about 20%.
Abstract: The transition process of grain boubary (G.B.) plate-like carbides have been researched in a Ni-base wrought superalloy under cyclic creep condition of temperature 1123 K, stress 392 MPa and hold time 8 (min). Its formative rule has been analyzed. Two kinds of different heattreatment method are used for getting different kinds of G.B. alloy, (straight G.B. and zigzag G.B.). The results of TEM analysis show that there are same process of transition particle carbides to plate-like carbides in both of G.B. alloy. There is a transition process from zigzag G.B. to straight G.B. before above process, i.e. the greater carbides which is not rule in size are broken up to particle G.B. carbides, (or straight process in brief). This process would take a long time. And so, the reason has been explained that plate-like carbides of zigzag G.B alloy are less than that of straiht G.B. alloy. A mode of transition zigzag G.B. to straight G.B. and of transition particle carbides to plate-like carbides is assumed in this paper.
Abstract: Based on the Kane's equation, a new general robotic dynamical algorithm, in which load-manipulator is divided, has been presented. The algorithm with closed-form is efficient in solving the dynamical problems of manipulator with closed-chain or opcned-chain, and generating the dynamical numeric-symbolic model of manipulator by computer. The algorithm has been derived and the characters of the algorithm has been discussed.
Abstract: The measurement noise and system noise in the practical process are studied. The analysis and the simulation results show that the impulse responses of them are different. It is profit for modelling aad system parameter estimation. The Rotation Matrix method is also proposed. It not only estimates system parameters but also finds the solution of ill-matrix.
Abstract: A study on the equilibrium between ferric and ferrous species in chloride melts has been made for better understanding of the behavior of iron species in magnesium electrolysis and moltensalt chlorination. At PCl2=101.325kPa. and experimental temperatures, the apparent equilibrium constant of the reaction can be given. At PCl2=0 and experimental temperatures, FeCl3 decomposed completely. It has been found that the measured values of K were in good agreement with the expected ones from the regression equations. The composition of melts, partial presure of chlorine and temperature had important effect on K. At the same other conditions, there were the maximunm values of K in system 3, indicating that the current efficiency of magnesium electrolysis would be lower if carnallitc was used as electrolyte, and that the catalytic effect of iron in molten-salt chlorination would be better when the content of KCI in the melts increaesed.
Abstract: In this paper, a simple thermodynamic calculation and mathematical method is applied to the calculation for Co-S-O ternary system. With, program designed with TRUE BASIC language, the predominant phase diagram was plotted by this program for this system.
Abstract: In this paper, an attempt is made to explore a new process for the production of high purity europium oxide. The process developed consists of a zinc reduction of europium to divalent state on a zinc column, follow by a single stage solvent extraction to remove major part of the trivalent rare earths, leaving the divalent europium in the raffinate, which is then subjected to extraction chro-matographic separation on a D2EHPA loaded resin column. Without the use of expensive chelating agents, as in the case of classical ion exchange technique, simple elution with dilute hydrochloric acid gives very high purity europium. Chemical analysis indicates that the separation from its neighboring rare earths is sharp enough to warrant its use in the preparation of various fluorescent materials. All trial runs in the laboratory achieved yields above 97%. Raw materials required are easily available in the market. Its potential for commercial production is quite apparent.
Abstract: The influence to the interferences on determination of Sb using five kinds of graphite tubes is reported. The introduction of microtube or platform, for its more homogeneous temperature, can increase the sensitivity and inhibits the interferences of foreign ions. The interference of nicle, which can not be eliminated with tube-in-tube technique, can be eliminated by the addition of EDTA; coating of Mo and W carbides and measurement of peak area.
Abstract: The vibrations of beam with a mass attached to its end is discussed. This model applied to civil engineering towers. By using Bessel functions, the frequancy equation is obtained. The frequancy rallies of the first mode, 2nd mode and 3rd mode for many cases are calculated. The fundamental frequancy calculated by present paper are agreement with other approximate method, but present method can calculate the frequancy of any orders.
Abstract: The magnetostriction methode which is bases on. the magnetostriction effect and anisotropic magnetical beviour of the ferromagnetic determination is presentted. The magnetic signal response during fatigue is examined by the special-made probe and the data process system. It has been found that a sudden signal change occurs at certain fatigue level which is correspoending to the certain level of plastic deformation. It is sure that after systematic standardization the magnetostriction method can be applied to the fatigue life estimate of the engineering materials and the structure members.
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
