Abstract: Studies on pyroelectricity of pyrite have been made in taibai gold deposit, Shannxi Province. Pyrite occurs maily N-P-type and p-type electricity conduction (N-electronic conduction,p-hole conduction). High P-type content and high absolut value of pyroelectricity coefficient indicated the good mineralization.From upper to lower of the ore body, from west to east of the ore belt, the P-type content is going down.That shows the denudation rate of ore body from large to small. Contour map of absolute value of pyroelectricity coefficient and isothermal map calculated from pyroelectricity shows that the deep and east of KT8 is the prospective ore area.The pyroelectricity differs with the kind of wallrock that may be result of the difference of deep of ore-forming.
Abstract: To overcome the difficulties in estimation of fractal dimension for fracture surfaces, anew method of fractal measurement called the projective covering method(PCM) is proposed. Based on the measurements by means of a laser scanner, the fractal dimension Ds∈[2, 3) of fracture surface is directly estimated by using this method. The research results agree well with the theory of fractal geometry and measurement data.
Abstract: Some of experiment study on the smelting superheat of molten steel was introduced to replule the superheat.The production of composite stainless steel strip by Inversion Casting Technology were introduced. The conclusion was the follows, when the thickness of mother sheet was 2mm, the temperature of mother sheet was 800~850℃ and the smelting superheat was controlled as 10~30℃,the production of composite stainless steel strip would be possible.
Abstract: The solidification model is set up based on consideration with mold flux as heat transferring medium. The size and width of gap due to contraction of steel in mold can be calculated,and temperature, width and state of slag film in gap are determined.The mold flux lubrication ability supports the increase of draw velocity in continuous casting.
Abstract: According to the calculation with current thermodynanics data, the oxygen content is controlled by the carbon content when the refining process is carried on in a condition of the vacuum degree being about 67 Pa and the carbon content being about 0.2% as well as aluminum content about being large than 0.025%.Because the sulfur content has a fixed relationship with soluble oxygen, the sulfur content is also controlled by vacuum degree and the carbon content. It is proved by the calculation that increasing vacuum degree is benefit for the increasing of stirring power and the decreasing of soluble oxygen content,so the conditions of thermodynamics and dynamics for desulphurization are provided.The results calculated are testified by the results of commercial refining of steel.
Abstract: The Static Recrystallization and Grain growth models of Q235 (low carbon steel) were established by regression with experiment data on the basis of physical metallugy models, the results calculated by the models agree with the measured values. The test are double compression,the condition of upsetting test is:temperature 950~1100℃, forming rate 0.50~0.20 s-1, initial grain size 56~85μm.
Abstract: The mathematic model simulating mold filling process with vector stream function-voracity method and turbulent flow model has been established, by which the mold filling process in casting has been modeled.The result calculated is in good keeping with the result measured, which demonstrates that fluid flow and heat transfer during mold filling can be simulated by this method.
Abstract: Cu and Al single crystals with molecular dynamics simulation method was studied.Under mode Ⅱ loading, the influence of loading rate on dislocation emission, width of stacking fault and dislocation velocity was analyzed. The simulated results show that width of stacking fault decreases as loading rate increases, while dislocation velocity increase dramatically.If loading rate is very high, system energy will be released by dislocation emission, the twinning is formed as well.
Abstract: The influence of phosphorus ranging from 10-5~1.3 × 10-4 on mechanical properties and microstructure of GH169(IN718) has been detected. The results show that phosphorus has a strengthening and toughening effect, i. e, to increase stress rupure life and ductility of GH169(IN718) at 650℃.
Abstract: The effect of hydrogen attack caused by exposure to hydrogen atmosphere at different temperatures and time on mechanical properties,fatigue crack growth behavior and fracture mechanism for Chinese made steels 20G,15CrMo and 2.25Cr-IMO were studied.The microstructure after hydrogen attack and the propagation path of fatigue crack have been observed by optical and electrical microscopy.The tensile tests showed that tensile strength and ductility decreased considerably with increasing of hydrogen attack.The COD testing indicated that fracture toughness material.The2.25Cr-IMo steel showed a lower susceptibility to hydrogen attack due to the action of element Cr and Mo,not resulting in a significant change in fatigue crack behaviour.It is suggested that the increase in the threshold K value could be attributed to the crack closure effect caused by the tortuous cracking path.
Abstract: In order to improve the lubricating behaviour of artificial joints,an overall new constructional design should be adopted.The materials with low elastic modulus and good lubricating behaviour,i.e.the elastomeric polymer,were developed.An oscillatoutype tribometer developed by ourselves was used to determine the frictional factor and to differentiate the lubricating mode for three kinds of bio-compatible polymer(i.e.silicone rubber,polyurethane and polyvinylalcohol hydrogel).The experimental results showed that the lubricating regime for the lubricated sliding pairs of sill cone rubber/316L stainless steel and polyurethane/316L stainless steel are boundary lubrication,and the lubricating regime for the lubricated sliding pair of polyvinylalcohol hydrogel/316L stainless steel is mixed lubrication.
Abstract: After aqueous poly(vinyl alcohol) solutions frozen-thawed repeatedly,dehydrated in vacuum and cross-linked by irradiation,a kind of artificial articular catilage-PVA-hydrogel was made up.The micromorphology of PVA-hydrogel has been observed by means of optical microscopy and SEM.DSC and mechanical tests have been employed to investigate the influence of freezing,thawing,dehydrating and irradiating upon th crystallity and the mechnical properties of PVA-hydrogel.
Abstract: The influence of different alloying elements and heat-treatment on the density and mechanical properties of the copper-infiltrated/sintered iron-based alloy was investigated. The iron-based alloy blank with high content of carbon and alloying elements was developed by mechanical mixing. After copper-infiltration/sintering, the material has the density of 7. 88 g/cm3 (the relative density of 98.2%), hardness of HRc 45.2 and TRS of 1 124 MPa. After quenching at 900℃ and high-temperature at 580℃, with large amount of martensite in the microstructure the material possesses the hardness of over HRc 40.
Abstract: From the point of improving the precision of steel tube wall thickness, the setting model of three-roll tube mill was derived, and the relevant setting characteristics was analyzed. Practical uses prove that this model is reasonable and reliable, and able to promote the setting speed of the mill and the precision of steel tube wall thickness.
Abstract: Based on the international standard ISO 7546-1983, the uniform mathematical model for calculation of the loader bucket volume and its formula are presented. By the complex method,the structural parameters of loader bucket and visualizes the optimization processes and results are presented.The results can be used to calculate the bucket volume precisely and design the bucket structure parameters rationally.
Abstract: The model consider additional moment effected on the stability of rolls. The content of the model include the decrease of incidence of incident of universal axis, higher the stability of rolls.Therefore it is theoretical foundation to set up. the optimum offset model for rolls.
Abstract: According to the affecting factors on the quality in products, the criterias for quality design and the robustness of design solution are disscussed and a new approach for the robust optimal design is investigated make use of principle for stochastic modeling. This method is defferentiated a general methods of robust design by that obtain the solution bring pass simultaneity to adjust the design variables and to control its tolerance. The evaluating results show that is a effective method.
Abstract: Solution of 3-dimmention instantaneous temperature field for work roll of steel strip hot rolling mill is the vulnerable spots when research into its thermal deformation.One kind of 2-dimmention model has been introduced. Moreover, on the basis of this model, the instantaneous temperature field of work roll has been simulated by means of finite element method with same results as the test and 3-dimmention model.
Abstract: The torsional vibration behaviors of mills under unsteady operating conditions are analyzed in terms of the dynamic torques in the drive systems.
Abstract: Energy system of the equipment used to make diamond film by the direct current-plasma jet (DC-PJ) was studied. Based on analyzing mechanism of heat transfer, the theory and experiment which research the level of varies of factors and the relationship of the factors were introduced. Five mathematic models according to temprature distrbution, radiation,convection,transference and heat balance were set up and calculated by this program, and got a consistent result both by calculation and by experiment.
Abstract: Presents a new synthesis method (displacement matrix method) to A-formed 4-bar linkages which coupler has a approximating straight line.With this method, it is easy to synthesize the expected linkages, and some synthesizing formulae are derived and a few examples are given.
Abstract: A feature variables based predicting model for complex production process was presented. Comparing with traditional methods,it bypasses the mechanism analysis,using time series analysis technology and feature variables,selected from original dynamicaldatad which can reflect the operating mode of complex production process build a new kind of predicting model.The neural network realization of this model is discussed.The results obtained by simulation show the feasible of this method.
Abstract: Deduces the matrix representations from original low-pass analogue filter to various ⅡR digital filters. This makes it possible to design ⅡR DF automatically by computer. A procedure of ⅡR DF design is programmed and a satisfying result is obtained based on some samples.
Abstract: A development graph tool to formalize a development process of program is proposed.It describes a collection of units that are related to each other in various way.This tool provides a possibility to solve analysis, modify management of a ddevelopment process, The use of this tool is showed with a example LWX of UNIX.
Abstract: In order to build up Computer-Dispatching-Locomotive System(CDLS) in China, the computer locomotive dispatching systemic software was studied based on the analysis of practical application of locomotive dispatching and computer in open-pit mine were.The locomotive running chart software and communication software were set up, and the experiments in room and in site were carried out.It shows the software system is reliable.
Abstract: Three-layered feed-forward neural network is used to establish the model for chaotic time series dynamic systems. Determination method of topology architecture for network is given.The size of the input node and hidden node is determined by the minimization the generalization error of the network. The simulation results show that the network architecture is optimized and the generalization error is dramatically decreased when this method is used.
Abstract: calcium in Baotou iron ores and its slags by AAS with air-acetylene flame,interferences and its eliminated method were investigated. The samples can be decomposed by composited acids, and interferences of coexist components can be effectively eliminated using the composited inhibitors of interferences (ascorbic acid +lanthanum +niobium). The simple method for determination of calcium was established with satisfactory results.
Abstract: The preparation method of Tertrasulphonated Copper Phthalocyanine (CuTsPc) L-B films was investigated, and their structure was studied by Uitra-Visible Spectrum. It was found that CuTsPc L-B films only can be prepared by colomubicelectrostatic interaction because the (CuTsPc) molecule is a long non-dimorphic chain molecule with a special planar structure. Experiments show that CuTsPc molecules in L-B films exist by dimer and lie parallel to the glass substrate plane.
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
