Abstract: Elastic-plastic FEM is used to respectively simulate the pit excavation under 7 different conditions of multiple piles retaining structure based on the engineering practice. The deformation features and failure mechanism of multiple piles retaining structure under different conditions are analyzed on the basis of numerical simulation results.
Abstract: FLAC 3D is used in the numerical simulation on the stope orepass stability in front and behind sumberged well and reinforcement. The reliability and reasonableness of reinforce technique are verified. Its important reference value could be used to similar stop orepasses.
Abstract: The difference betWeen the systems of CaO-SiO2-H2O and CaO-SiO2-Al(OH)3-H2O, was studied,especially the effect of Al3+ on the crystallinity of tobermorite was focussed. As a result, in the system of CaO-SiO2-H2O, tobermorite formed early, howevey, with reaction time forward, tobermorite was replaced by xonotlite. So far as CaO-SiO2-Al(OH)3-H2O was concemed, hydrothermal reaction was carried out under the same condition as CaO-SiO2-H2O to study the morphological changes of tobermorite crystals. It was found that Al3+ accelerated the crystal growth of tobermorite to some extent and was in favor of platy crystals. Moreover, with the Al3+ content increasing in the starting material, the morphology of tobermorite did not change magnificently, but platy crystals became more and more eminent. As soon as the Al2O3 content was over 15.6%, synthetic mineral greatly changed in structure and turned into hibschite different from 1.1 nm tobermorite. Obviously, xonotlite was not apt to form in the presence of Al3+.
Abstract: The composite method of field experiment and numerical calculation is used to study the effect of filling the shot holes with surface-active detergent solution to reduce the explosive gas and dust in open-pit mine. The result shows that the volume of explosive gas and dust can be decreased 50% by using surface-active defergent solution instead of rock cuttings to fill the shot holes. This technique reduces environment pollution in deep open pit mine.
Abstract: In vacuum, several high speed steels which have decarbonization layer were annealed and the diffosion of carbon in high speed steel were reviewed in free-oxygen condition. The decarbonization of high speed steel relate to the decompound of carbonization and the diffusion of free carbon in the high speed steel.
Abstract: Rolling characteristics of continuously cast slabs with liquid core is studied with the aid of elastic-plastic and thermal-mechanical coupled FEM. The effects of shell thickness and related heigh reduction on stress and strain distribution are analyzed during cast-rolling with liquid core in thin slab continuous casting.The stress and strain of the shell increase with increasing shell thickness for the sarne related heigh reduction.The strain of the shell increases with increasing related heigh reduction for the same shell thickness.
Abstract: The Grain sizes of solidification structure of T8 liguid steel were reduced significantly after electropulse treat ment. The form of dendrites was disappearing when the electropulse voltage rose. The shape of steel perlites was also changed after electropulse. A empirical equation was obtained between the number of crystals and electropulse voltage.
Abstract: Textures in different layers of superconductors based on YBGO system are analyzed using the methods of pole figure and conventional Φ scans. It is shown that the Φ scanning technology has only 1-dimensional description and could omit some information of 3-dimensional orientation distribution, which will in-fluence the superconductor quality. The pole figure method, in contrast, demonstrates the orientation distribution 2-dimensionally and gives a comprehensive view of thin film texture, which is a much better method for texture analysis in superconducting films,in which there is commonly an unique high sharpness texture com-ponent.
Abstract: The temperature independence law of the effect of third component on the saturated solubility of carbon in Fe-V melt was put forward,and the solubility expression of carbon in Fe-V melt was got with the saturated solubility of carbon of this work and reference data at different temperature, and these thermodynamic property parameters were calculated. At the same time the applied analysis for the transition temperature of vanadium oxidization were carried out and the result approaching the practical production was made.
Abstract: According to the coexistence theory of slag structure as well as the measured viscosities of CaO -MgO-CaF2-SiO2 -Al2O3 at different temperatures and compositions,calculating models of mass action concentrations for CaO -MgO-CaF2-SiO2-Al2O3, melts and viscosity for these melts have been formulated. The results of calculation agree well with practice, showing that these models can reflect the structural reality of the melts and the relatonship between viscosities as well as the mass action concentrations and temperatures of the melts.
Abstract: A serial of contrast experiments were carried out on induction furnace. It's found that a betterdesulphurization result exists in the top slag plus sire injection Process than in the single top slag process. Slag which contains BaO has stronger desulphurization ability than that does not. CaSi alloy can decrease the terminal sulphur content in the steel when[O] and[S] are low Further, some basic technological parameters were proposed for the refining of ultra-low sulphur steel.
Abstract: A1-20Si-5Fe-3Cu-1Mg alloy was synthesized by spray atomization and deposition technique.The microstructure and mechanical properties of the spray deposited hypereutectic Al-Si alloy were studied using optical microscopy, scanning electron microscopy, X-ray diffraction, and tensile tests. The effects of iron on the microstructural evolution of the high-silicon aluminum alloy after extrusion and heat treatment have been examined.The tensile test results indicate that the spray-deposited Al-20Si-5Fe-3Cu-1Mg alloy has better strength than the powder metallurgy processed Al-20Si-3Cu-1Mg alloy at elevated tempeate.
Abstract: α-SiC ceramic was obtained by hot-pressing of α-SiC powders with B and C as additives. The relative density of the materials is 97.8%, which was hot-pressed at 1900℃ and 25 MPa. The values of the flexural strength and fracture toughness reached 383 MPa and 4.95 MPa·m1/2 respectively.The densification mechanism was deduced.
Abstract: The effects of different firing temperatures on the stability of perovskite phase, grain size, and dielectric properties were investigated by XRD, TEM, SEM and dielectric measurements. The dielectric ceramics of Pb(Mg1/3Nb2/3)O3-PbTiO3-BaTiO3 system were obtained by chemical coprecipitation in water. The ceramics have higher dielectric constant (7003-9714), lower firing temperature (950-1150℃), quite uniform microstructure with grain size less than 2.5μm, and lower temperature coefficients of capacitance. As a result, it was confirmed that the simple and low cost chemical route used namely coprecipitation in water is a desired meth-od for preparing high property dielectric materials applicable to multilayer capacitors.
Abstract: On the basis of analysis of developing background and theory of thermoelectric graded materials, p-type (Bi1-0.85Sb0.85)2Te3 and PbTe two segments thermoelectrical graded materials (TGM) with different barriers were fabricated by conventional hot-pressing process. Metals Fe, Ni and Mg were used as barriers between two segments.The thermoelectric properties were measured. The compositions of each layer and composition distributions in and between different layers were detected. It is demonstrated that better diffusion barriers materials were metal Fe.
Abstract: WC-65Mn metal matrix composites was produced by the IMS (incremental melting and solidification)process in order to research and develop a process making metal matrix composites. The processing parameters of IMS, including power supply and mould velocity of movement etc, were researched.The microstructure was observed by SEM and the distribuions of WC particles were quanficationally measured with the aid of IMAGE TOOL soft, and at the same time the mechanical propertes were tested. The results showed that the distributions of WC particles were uniformity, in addition, the bend strength and degree of hardness were all good at the condition of suitable power supply and favorable mould velocity.IMS process can be a method to produce metal matrix composites.
Abstract: Numerical computation soft of Incremental Melting and Solidification (IMS) initial process was designed. In the condition of different coil current and frequency and different kinds of materials and size, induction current and temperature distribution of treating materials could be obtained, and the input power and melting time of materials also could be calculated. This soft might be used to select processing parameter of IMS.
Abstract: Supporting the study of artificial articuar cartilage materials, the research and development of an artificial synovial fluid of Hyaluronic acid (HA) was carried out. With two lubricated sliding pairs, PVAH/316L and PVA-H/PVA-H, an modified oscillator-type tri-biometer and M-2000 wear test machine were used to detemine the rehological properties and lubricating behaviour of a series of HA solution.The experimental results showed that the solution of HA had the rehological properties similaring to the natural synovial fluid to a cehain eXtellt, and decreased the ffiction and wear of tWo kinds of lubricatCd sliding pairs, also it rendered abetter 1ubricating effection on PVA-unVA-H than on PVA-H/3 l6L. The sofution of HA with O.75% (massfraction) showed a better lubricating behaviour than 30% (volumic fraction) Bovine Serum. So HA solutionwould be a promising Anficial synovial fluid.
Abstract: Surface treatment to the Ni3Al intermetallic compound was conducted by high energy density plasma and nanometer micro-crystalline layers were developed on the alloy surface.Formation of protective Al2O3, scales on the alloy surface was promoted by increasing the nucleaton sites and enhancing the outward ditheion of Al in the micro-crystalline structure. The fast growing phase NiO was eliminated in the oxide scales.
Abstract: The precipitation behavior of FeTiP phase in P-added high strength IF steel, as well as its influence on the hardness were analyzed. The precipitation hardening effect in P-added IF steel was found. The experiment demonstraes that the hardening effect is more obvious during the aging at 550℃. The key reason of the hardening is the fine precipitation of FeTiP phase, which precipitates not only on the grain boundaries but also inside the grains.The atom ratio of Fe:Ti:P of FeTiP phase is not the exact ratio of 1:1:1 during the aging at 750℃. It is believed that the hardening effect induced by non-carbontrides e. g. FeTip in high purity and ultra-low carbon micro-alloyed steel should be investigated further.
Abstract: A study has been done on the accuracy and reliability offractal dimensions determined through slit island methods by employing Koch curves. The effects of various constructing factors such as initial size length, shape and looping level on the fractal dimension determnation have dimension detemlination have been investigated. Asa result it is proposed that the slit island methods should not be used in the fractal dimension determination at nanometer scale.
Abstract: The effects of filling density preheating temperature and additives on the ceramic lined steel pipe made by thermite-gravitational separaion process were studied. It shows that the propagating rate of the combustion wave along the steel pipe decreases with increasing the filling density and increases with increasing the preheating temperature. Furthermore, it becomes contrellable with the addition of suitable additives.The coal powder nozzle produced by thermite-gravitational separation process has been used in blast furnace.The bend pipes with the diameter of 50~273 mm were also produced by this process.
Abstract: By considering the data correlation and using the fuzzy cluster of pattern recognition,the relationship among varions corrosive factors of soil was investigated. Both the matrix of correlation coefficients and the pedigree of factor clusters show that some factors are correlated closely to each other, while others are relatively independent. The correlation coefficients are very high between the parameters such as organic substances and total nitrides, organic substances and microorganism total salts and conductivity, density and void volume etc. However, the CO32-, sulfur oxide bacterias etc., indicate much lower correlation coefficients with soil pH. And the 23 soil corrosive factors are clusterd into 6 distinct clusters under the correlation coefficien value above 0.8. The results of will be helpful to the further study on the soil corrosivity of petroleum asphalt coated pipe.
Abstract: The morphology of oxidation film has been investigated in Fe-Cr alloy contained cerium by SAM and XPS as well as SEM. The constituents of oxidation layers at different depth have been measured at intervals some nanometers and the constructs state and real-time have been analyzed. The experimental results show that chromium migrate outwards so that the composition and structure of oxidation layers change and cerium atoms diffuse and segregates on interface. The influences of trace cerium on the diffusion of alloy element chromium further have been investigated durig oxidation.
Abstract: According to the theories of fraction and vibration, the reason of the unsteady tension can be illustraed by a new method.Negative damp friction should bring on self-excitaion vibration of work rollers and this cause for unsteady tension. The characteristics of emulsion are studied.It is demonstrated by rolling production that reducing the content of emulsion can increase the stability of rolling tension observably.
Abstract: The application of BP neural networks and predictive control algorithms to AFC (Auto Flatness Control) system is studied, and a predictive control algorithms based on BP neural networks are offered.Simulation by computer using data get from 1420mm CVC tandem mill of Shanghai Baoshan Iron and Steel Company is investigated. The results show that this algorithms can be applicated to AFC system and it's results are good.
Abstract: Using the ANSYS finite element method, a series of planar models was put forward to analyze and calculate strip buckling, post-buckling on the condition of the different typical shape shape stress and the different ratio of strip width to gauge. The control target model of strip flatness control was found and the calculated result show that the efficiency of model has been proved.
Abstract: Using 8031 to control armature current for constant tensil-stress reel control system has been studied. The control method for diameter filter and dynamic current filteris is discussed.
Abstract: Some defects of the traditional rolling force models of cold tandem rolling mill were found out, and new rolling force models based on genetic neural networks were set up. The comparison results of the measured rolling force of cold tandem rolling mill with the calculated value from the traditional models and also with the calculated value from the new rolling force models based on genetic neural netWothe show thatthe calculating precision of the new models is better than that of the traditional models.
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
