Abstract: The distribution of mineral particles on soil landslide is protogenous and random before the creation of sliding zoon. Under the action of stress field, the arrangement of mineral particles is increasingly regulated, up to the landslide losing stability. The change of the distribution of the particles is correspondent with the development process of landslide. It can be measured by fractal.
Abstract: This paper discusses on the engineering of decision support systems for underground coal mine planning and production scheduling based on the experiences from developing a practical computer-based management information system. Particularly presented is a methodology for engineering decision support systems for underground coal mine planning and production scheduling, including an integration of computer graphics, database management, mathematical modeling and knowledge, engineering techniques and a coupling of the life-cycle and prototyping software-engineering processes to support system quality assurance.
Abstract: The injection oxygen and pulverized coai into blast furnace for intensifying Ironmaking process is of tremendous profits. The results of the experimental study and production practices show that the coal/coke replace rate can be raised by injecting the bituminous coals into blast furnace, decreasing the ash content in coal, increasing the temperature of the hearth in blast furnace, improving utilized level of gas, and the combustion rate of pulverized coal can be raised by increasing blast temperature, using the oxygen-coal lance with high efficiency which can supplied full oxygen directly to blowpipe of blast furnace and intensify mixing between oxygen and pulverized coal, using dispensation technique of coals, adding combustion accelerative agent to pulverized coal.
Abstract: The microstructure of Al-12.7%Si eutectic with addition of 0.1%Sr has been investigated across arrange of growth rate from 30 μm/s to 2 500μm/s with the aid of TEM. It has been shown that eutectic silicon phases contain high density of twins on two or more {111} systems and twin density and behavior are dependent on the growth rate. The preferred growth axis of silicon phases is in a <211 >irection and the microstructure of silicon phase can been seen as consisting of subgrains seperated by microtwins and/or stacking faults. Eutectic aluminum phases is multicrystal. There are no preferred matching relationship between eutectic aluminum and silicon phases.
Abstract: Considering the influence of the Soret effect and the constrained convection caused by non-uniformity of radial laser energy distribution on solute distribution, the distribution of solute at the interface in non-equilibrium solidification of laser surface alloying is analyzed, and a new formular describing solute distribution factor on the basis of Aziz's model is put forward.
Abstract: A parameter Kmax indicating the nature of the materials has been suggested by present work with which the Al-alloys can be classified into two categories:in alloys with Kmax<0.1 only continuous dynamic recrystallization can occur and it cannot proceed completely; in alloys with Kmax>0.1 occurs only dynamic recrystallization. The characteristics of the dynamic recrystallization of Al-alloys has been discussed.
Abstract: A Ti-12Co-5A1 alloy sheet with an ultra fine α-Ti+Ti2Co microstructu was obtained after a proper melting process and thermomechanical treatment. The all under this state exhibits very large superplastic elongation at relatively low temperature ar high strain rates. The elongation more than 1 500% was obtained at a strain rate of 3×10-2s-1 and 700℃. The superplastic deformation induced the size increase and shape chan of Ti2Co intermetallic particles. No cavity was found in the specimen after superplast deformation to 500%.
Abstract: Crack propagating process in a Ce-TZP ceramics was in-situ observeed in TEM. It was found that the crack propagating process in this ceramics, similar to that in some metal materials, was microcrack nucleation ahead of main crack tip, microcrack growth, then main crack connecting with the micro one and propagating forward. The martensitic transformation of zirconia, induced by crack tip stress field, was observed in the vicinity of crack. Crack deflection was also observed in the ceramics. It was also found that the main crack tip was not sharp, it was a blunted crack.
Abstract: The recrystal course is observed through annealing temperature of 800℃ and variation annealing time in extra-deep drawing IF steel. It is processed in soak temperature of 1 200℃, finish temperature of 930℃, coiling temperature of 700℃ and cold reduction of 80%. According to experamental result, the recrystallization nucleation principle in preliminary annealing is discovered in IF steel of micro-carbon, micro-titanium and micro-niobium. The principle is that the recovering, poly-gonization begins at the subgrains of {111} orientation, then these subgrains grow up prevailing. The texture mainly consisting of {111} orientation is formed.
Abstract: Liquid forging processing to thin wall waveguide angle head has been experimentally studied. The results show that the dimensional tolerance of waveguide angle head by liquid forging processing are 0.02-0.04mm, it meets the requirements of standardization, building block system, built-up type and stability to waveguide parts. This new technology can increase high percentage of stock utilization and productivity efficiency, and lower cost.
Abstract: With the co-operation between the small stiff convexes and small plastic convexes, the co-operation between rolls and rolled piece has been simulated. Combining the up-bound method with the slipping-line method, the model of micro shape on the touching surface has been optimized. The influences of the micro geometry shape of small convexes and the joint strength between convexes on the frition factor are studied.
Abstract: An experimental setup and a simulated ceramic chip carrier for study of the SMT solder joint reliability under thermal cycling have been developed. The influence of metal plating of chip carrier on the reliability of the SMT solder joints under thermal cycling has been studied statistically.
Abstract: A approximate method for energy gap calculation of oxides is introduced in detail, and is applied for the gap culculation of high-TC copper oxide superconductors at normal state. It is revealed from the result that, most oxide superconductors at nomal state have the gap values within 8.50-8.80eV. In the same system, the variation of Cu-O layer structure results in the increase of TC upon the decrease of Eg, while in YBa2Cu3Oy, the variation of oxygen content results in the increase of TC upon the increase of Eg. Further analysis shows, the Eg values of high-TC oxides at nomal state have a close relationship with superconductivity, and the average ionization potential is the major factor in determining the Eg values.
Abstract: Based on previous theoretical models of cavity nucleation during creepdeformation, a new cavity nucleation model is proposed. The basic idea of this new model is that cavity nucleation during creep deformation depends not only on the stress concentration of piled-up group of dislocations, but also vacancy clustering. From the critical radius of cavity nucleation inferred in this paper, not only Raj's critical radius formula but also Smith's critical stress for cavity nucleation can be obtained. The new cavity nucleation model proposed has a wider application than those proposed before.
Abstract: Small amount of H3BO3, SrCl2 or SrF2 improved the specific gravity of calcined SrCeO3 based powder. The addition of 2% SrF2 made the specific gravity close to the theoretical. The results of DTA, TG and XRD shown that the addition of fluxes accelerates the formation of SrCeO3. Using the precursor powder, ceramics having density above 94% of the theoratical have been sintered. The measurements of AC impedance and EMF of hydrogen concentration cell shown that the addition of SrF2 does not degrade the material properties. The proton transference number is close to unit in the temperature range of 773-973K.
Abstract: The currently used thermodynamic models for the Fe-C interstitial solutions have been examined in detail for the first time. Results show that none of KRC, LFG/MD and X-K models can be employed to establish the thermodynamic criterion for the spinodal decomposition in austenite and ferrite (martensite) in steels.
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
