Abstract: The DDT sensitivity of powdery emulsion explosives (PEE) containing aluminum or not is investigated. It is found that PEE can not self-keep burning and DDT occurs when the content of aluminum is less than 4% without external adequate and continuous heat energy. When the content of aluminum is higher than 8%, the burning of PEE hastens obviously and the DDT sensitivity increases largely. It is concluded that the DDT sensitivity of PEE is affected by many factors such as restriction, loading density, particle size, and the content of aluminum.
Abstract: The feasibility of using the second compensate tension to solve the prestress-losing problem was analyzed with the methods of numerical analog calculation and experiment according to the reinforcement project of 104 National Road in Shandong Province. The result indicated that the reciprocity of the closer anchor and the prestress attenuation can be effectively eliminated using the second compensate tension. It is concluded that the problem of prestress-losing should be considered in the course of design and construction and be solved with the method of the second compensate tension in the soil reinforcement project of prestressed anchors.
Abstract: The experimental treatment of waste emulsion of some steel tube company was conducted using the demulsification, floatation and carbon adsorption process. W25 and Sodium hydroxide were adopted as emulsion breakers. The final wastewater can reach the national standards of China.
Abstract: The technological characterstics in the thin slab casting and rolling process are introduced. Some key techniques are analyzed and discussed, which include Liquid Core Reduction (LCR), Dynamic Soft Reduction (DSR), Electro-Magnetic Brake (EBM), semi-endless rolling and ferrite zone rolling.
Abstract: An industrial experiment with rougher pulverized lean coal was carried out in 1# BF at Anyang Iron and Steel Group Co. The production of coal grinders increased by 21% as the mixing rate of the pulverized coal size under 74 um was reduced from 70% to 30%. With rougher pulverized coal, the raceway became longer and the PCI ratio as well as replacement ratio of coal enhanced. The two ratios increased as the oxygen was enriched. It is shown that much good economical benefit in BF has been reached by using rougher lean pulverized coal.
Abstract: Taking the mold of No.1 continuous slab-casting machine in Baosteel as the object, a multi-phase model was applied to simulate the velocity, temperature fields and gas distribution of molten steel with argon injection. The results indicate that the velocity of upward flow increases, the lower re-circulation region appears small, and the temperature gradient decreases. Argon bubbles distribute unevenly and the gas holdup of liquid steel in the upper region is far higher than that of the lower region.
Abstract: The process of design and manufacture for a self-regenerative burner was briefly described. Experiment was carried out by the self-regenerative burner. The results show that this system has advantages of high-efficiency heat recovery, low NOx emission and simple configuration.
Abstract: The interfacial energy between two liquids of metastable miscibility gap is an important physical chemical parameter in the research of phase separation mechanism, but it is difficult to be measured. In this paper the interfacial energy in M-Cu (M:Fe or Co) alloys was evaluated based on Becker model and the alloy phase diagram data as well as the excess thermodynamic data from SGTE alloy solution database.
Abstract: To investigate the effect of initial grain size distribution on normal grain growth, Monte Carlo simulation was performed starting from an initial microstructure with the Weibull grain size distribution in two-dimension. The results show that the grain structure evolved alike with the initial, and the grain size distribution of the quasi-stationary state could be described well by the Weibull function but not by classical Hillert distribution. Comparison with some other results further suggests that Weibull distribution with different β values may well be used to describe the quasi-stationary grain size distribution.
Abstract: A corresponding three-dimensional steady state model concerned with dendrite growth is analyzed considering the influence of a uniform convection field. By using Fourier series, an eight-order ordinary differential equation is finally solved and an accurate analytic solution is obtained in a very neat form. The correlations among coefficients in the analytic solution are determined. The obtained solution shows that the crystal growth in the steady state presents cyclic oscillation attenuation along the dendrite growth direction under the influence of a uniform fluid field, and this feature is an intrinsic character.
Abstract: The lattice parameter variation of stoichiometric Ni3Al and NiAl during the order-disorder transformation was studied based on the embedded atom method (EAM). The order-disorder transformation for Ni3Al is of the first order transition, and the lattice parameter changes linearly along with the long range order parameter. NiAl is in the second order transition, and the relationship between the lattice parameter and the long range order parameter is nonlinear. The lattice parameter variation during the order-disorder transformation depends on both the phase transition type and the mechanical equilibrium condition. The lattice parameter should change linearly for the first order transition and nonlinearly for the second order transition.
Abstract: Effects of annealing temperature on microstructure and properties of pure copper wires containing unidirectional fibrous crystals fabricated by unidirectional continuous casting process and heavy deformation below recrystallization temperature were investigated. The copper wire was annealed in a vacuum firing furnace for 1 h at 200, 300, 400 and 500℃ respectively, then was cooled down in the furnace. By observing the microstructure and analyzing the mechanical properties and electrical conductivity of the copper wires before and after annealing treatment, it is shown that at the annealing temperature below 300℃, the microstructure of the wires still remains fibrous crystals without evident changes, the tensile strength decreases slightly, and the elongation increased a little. After annealing at 400℃, the wires were fully recrystallized and compound twins could be found. After annealing at 500℃, the recrystallized grains coarsened. When the annealing temperature was higher than 400℃, the tensile strength decreased apparently and the elongation increased greatly. When the annealing temperature ranges from 200 to 400℃, the electrical conductivity increases by a small percentage (lower than 2%).
Abstract: Nanocrystalline TiO2 films were made on ITO glass with sol-gel method and powder-coating method. By X-ray diffraction and TEM, it was shown that the TiO2 films were mainly anatase structure with a grain size about 30 nm. The surface of TiO2 films with powder was observed by SEM. The behavior of NPC solar cells composed of the TiO2 films was analyzed and a method to prepare nanocrystalline TiO2 films was proposed.
Abstract: A sol-gel process to fabricate Ag-doped Na2O-B2O3-SiO2 glass was presented. The flow sheet for experiment was described. X-ray diffraction and infrared absorption spectra were used to determine the structure and its change during fabrication. The optical absorption spectra and TEM were used to testify the existent of Ag colloid particles. The results show that the glass made by the sol-gel method has the same structure as that made by the molten method, and Ag particles with a distribution of sizes have been obtained after well-controlled heat treatment. This method can be used to produce color glass and its product was also the raw material of other devices.
Abstract: High current extended DC arc plasma equipment was manufactured to carry out CVD film deposition on acid-etching and boronizing samples of the cemented carbide cutter YG6, and the surface coating of deposition at different positions of the blade were analyzed by Raman spectra and SEM. The results show that the boronizing pretreatment technology is superior to the acid etching pretreatment technology, for CVD film coating on the blade by boronizinf pretreatment has advantages of large area, good homogeneity and high quality.
Abstract: Nanoscale CuO powders were prepared by roasting a basic coppper carbonate precursor at 350C for 1 h. The obtained sample's microstructure was determined by XRD and TEM analysis. The results show that the diameter of the nanocrystalline is 30 nm. CuO sol were prepared with dodecylbenzene sulfonate solusion and at pH=3.0 adjusted by HNO3.
Abstract: Convection heat transfer coefficient and equivalent radial thermal conductivity are discussed, which have great effect on heat transfer in a HPH furnace. Using the approach of mathematical modeling, the convection heat transfer coefficient on each surface of a coil are studied for the complete cycle of annealing. In view of the analysis of thermal resistances, the equivalent radial thermal conductivity is investigated for different temperatures, compressive stresses, and atmosphere gases, respectively. It is shown that the HPH technique can significantly enhance the heat transfer compared with the traditional HHX method.
Abstract: The property improvement of the semi-steel roll surface after laser quenching was investigated experimentally, and the effect of technological parameters on laser quenching was analyzed. The thermal circulating procedure of the surface under the laser beam was elaborated by numerical simulation methods and the principle of laser quenching on the surface is explained consequently. The distribution of thermal gradient near the laser spot was obtained, and the reason for crack formation during laser beam scanning was discussed.
Abstract: The first set of dynamic simulation system of cold strip rolling mill is built by using the simulation software MATRIXX. The construction and main functions of the dynamic simulation system are described. The simulation system has integrated functions and the simulation precision is more than 95%.
Abstract: Vibration signals of a gearbox were analyzed by discrete wavelet transform. The abruption information of a bolt in the gearbox was obtained. It is shown that wavelet analysis provides an effective analysis technique for judging and avoiding the same accidents.
Abstract: Based on the synthesis theory concerning the mixed point straight-line four-bar linkage in the special condition, a research method taking the circle center and circle point as parameters is proposed. Synthesizing formulae of three parameters in the common condition are derived and a few illustrated examples are presented.
Abstract: The theory of fuzzy probability should be applied to quality design for product because of product characteristics with both randomness and fuzziness. After the randomness and the fuzziness are analyzed and the concept of zero defect design is defined, the theory of zero defect design based on fuzzy probability is proposed and the corresponding mathematical model is built. It is proved by an example that this model can be used to improve product quality greatly and has practical application in quality design for product.
Abstract: To realize the optimized hybrid machine benefits in practice, a control system is designed. These comprise an inverse model feed-forward controller with a neural network feedback element and a integrate neural network in which the controller and plant model are combined to form a five-layer neural network. The neural network feedback element constructs a self-tuning loop. The results indicate their potential for practical use and their feasibility.
Abstract: A improved subpixel edge detecting algorithm based on polynomial interpolation, masks and calculating formulae is introduced, the error cause of the operator is analyzed, and the error formula is derived. The algorithm uses direction masks based on classical Sobel masks in converting gray into gradient images and applies the polynomial interpolation to subpixel edge detecting at the gradient direction of edge on gradient images. Some examples are presented to demonstrate the effectiveness of the method.
Abstract: The structure of the artificial immune system is introduced, and the immune genetic algorithm for optimization is proposed. A application of the algorithm to optimization for the coke ratio of a blast furnace shows that the algorithmthe is very avaiable.
Abstract: A ferrite/bainite dual-phase low-carbon microalloying steel has been obtained by special microal-loying design and optimum thermo-mechanical control process(TMCP). The microstructure shows that there are some amounts of ferrite/quasi-polygonal ferrite on the prior-austenite boundary and/or within the grains, and the rest of matrix is ultra-fine lath-like bainitic ferrite. The ferrite grain size is also very fine (about several microns). The mechanical properties of this kind of dual-phase steel show that the yield strength do not decrease obviously comparing with the ultra-fine bainitic steel, but the elongation increases. For a 700 MPa grade dual-phase steel (tempering at 680C for 1h), the elongation is more than 25%. This kind of dual-phase low-carbon microalloying steel has the advantages of more than 700 MPa grade strength and good ductility.
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
