Abstract: According to electron probe analysis of 12 samples, As, Se, Ni, Au, Pt were detected as trace element in pyrite. Pt content is negahve correlated with Au+Ag content The native gold is closely associated with pyrite from stage 2 and stage 4. It occurs is the, fissure filling or on the crystal boundary of pyrite.The finess of gold is falling from 1290 level to 1350 level, which indicated that the ore-forming temperature is from high (downside) to low (upside). Pt content is negahve cormlated with the finess of gold. High Pt and Te content indicated that the ore forming of this deposit is related with abyssal magmatism. Pt content of pyrite is not only genesis significance but also of significance of explorahon.
Abstract: In diagnosis of engine, working conditon is the basis of data analysis, condihon evaluahon and fault diagnosis. Rotating speed signal shows the working condihon.Speed varies with different working condihon. The speed-time model can be obtained by polynomial regression under different working condihon. On the basis of fuzzy pattern recognizaton method, prachcal working condihon can be determined.
Abstract: The effect of starch, lime, sodium hydroxide and RA-315 contained in the reclaimed water from wiling pond of Diaojuntai concentrator on the flotation process of Qidashan concentrator were inveshgated in the laboratory. The results show that the main fator influencing the flotahon process was pH value of the reclaimed warer. The presenc of stareh and RA-315 also influences the process, but this influence can be reduced to acceptabe level by decreasing the dosage of collector used. The reclaimed water from the tailing pond of Diaojuntai concentrator can be direchy used as flotation water in Qidashan concentrator.
Abstract: The determination conditions of fluorine was systematically inveshgated being emphasised on the interferences of coexistent elements and their elimination. The analytical method for fluorine in Baotou iron ores and its slags was developed.
Abstract: The colour reachon of niobium(V) and sulfochlorophenol S has been system-atically investigated.The condihons of the reachons were optimized and analytical character-istics of this colour system were examined. A decomposition method of the samples was studied and the spectrophotometry for determination of niobium in Baotou iron and its slags was developed.
Abstract: The hot ductility of Nb-Ti containing X-52 steel cc slab has been examined over the temperature range from the melting point to 700 ℃.The loss of hot ductility was analyzed according to the charateristics of fractures and precipitates. It was found that there exist two low ductility temperature regions within the tested temperature range, that is, Region Ⅰ from the melting point to 1380℃ and Region Ⅲ from 925-825℃. In region Ⅲ, the ductility loss is due to the dynamic precipitation of fine partiocles of NbCN at the austenite grain boundaries. The good effect of titanium on hot ductility is attributed to titanium reducing precipitation of the more detrimental NbCN and preventing the formation of ferrite films around the austenite grain boundaries.
Abstract: 3D mathmatical model of heating process with electric arc-electric slag on nonstandard orthogonal coordinates system in DC electric arc-electric slag ladle furnace has been developed and computered completely. By using vetor stream function equation and vorticity transport equation the velocity field has been computed. The Rechard-son buoyancy revising item was considered in k-ε two equations turbulance model. The temperature field was expressed by unsteady energy transport equation. The measured temperature field in testing ground is in accordance with calculared results.
Abstract: The nucleation and growth models of the microstructure formation of spheroidal graphite cast iron from solidification down to room temperature were estab-lished according to the existing solidification kinetics theories. Based on the solidifocation kinetics models, a 3D finite difference code, FTStructure, has been developed to simu-late the formation of microstrucures and to predict the as-cast mechanical properties of the SG iron. The cooling curves, microstructures and Brinell hardness of SG iron speci-mens were simulated. Good agreement was obtained between the calculated results and those of experiments.
Abstract: To avoid unnecessory retirement or unexpected failure of large components operating at elevated temperature, a method is recommended to choose a reasonabl value of confidence of life predition for components. Monte-Carior method is used to estimate the lifehme of discs used in oil refinery power recovery gas expanders.
Abstract: Three-dimentional grain size distribution might be well described by a gamma or a lognormal distribution. On the basis of these two Kinds of distribution functions, the relationships of the characteristic parameters between the volume-weighted and the number-weighted grain volume distributions are derived theoretically and demonstrated experimentally. The method can be used to estimate the grain volume distribution parameters, such as the average grain volume and the coefficient of variation of grain volume distribution, from two-dimensional measurements on sections through polycrystas,
Abstract: The drawing die design by the use of the variational method for special shaped steel was studied.It was proved that the variational method is simple and feasible for CAD of the drawing die design.This method was successfully used in the drawing die design of the wobbler spindler.
Abstract: The mechanical properties of domestic and England PAN-based fibers are measured.The chemical composition, relative molecular mass, thermal property, crystalinity,orientation and microtructure of two kind of fibers are studied by chemical analysis, GPC,TGA, X-ray and SEM, etc. On the basis, the relationship between these fibers structure and the property is analysized.
Abstract: The total transport coefficients of nitrogen from reducing slag containing carbon into liquid steel in Al2O3 crucible at 1600℃ have been measured. The result shows that β has been related to the panial pressure of nitrogen in gas phase PN2, β increases with the increase of PN2 The calculated results of mass balance was shown that under this experimental condition β0 =3.7×10-4 cm/s.
Abstract: An artificial neural network was established to forecast the surface tension of pure metal from the experimental data of atomic radius, melting point, boiling point and atomization enthalpies. The trained network can represent the relahonship between the input factors and output factor (surface tension).The associated and forecast data for more than 40 pure metals are acceptable considering the deviation of the experimental dara for surface tension, which shows a good prospect of artificial neural network in the prediction of surface tension of pure metals.
Abstract: Koiter's Initial Postbuckling Theory is applied to analyse the long thin-walled casing under uniform external pressure, from which it is concluded that the long thin-walled casing under uniform external pressure owns postbuckling stablity.
Abstract: Deals with the experimental investigation on the reliability of gear-tooth fatigue for through hardening steel 35CrMo. The tests were canied out on a electro-mag-netic resonance fatigue test machine of type 1603 (U. K). Four loading stress levels (7 sample for each test) were conducted. Based on the test data, a R-S-N curve and related equation were fitted. Finally, the limiting bending fatigue strengh of the 35CrMo gear-tooth under different reliability have been evaluated.
Abstract: The Selection of processing pararneters is the most important step for the cross wedge rolling designing. The fuzzy information processing methods are used to analyze the data of dies, and the fuzzy relationships among technological parameters as well as theer applications are presented. By using the fuzzy reasoning methods, the parameters such as formation angle α, contraction ratio of area φ, can be determined automatically in the CAD system.
Abstract: A large quantities of on-site datum were sampled. On the basis of the classical rolling force theory areasonable structure with regard to the model has been selected.The mathematical model is regressed with the least squares method and the same time adaptive algorithm is put forward, analysis of the accuracy is also presented.
Abstract: The method of pseudo-random correlation identification is apppied to identify the space impulse response,and it's proved to be effective and precise. In the experiment of active noise control, the good result is achieved by using this method.
Abstract: The oxides formed on the surfase of metals have the influence on the radiation absorption. Increase of the roughness and thickness of the oxides on the metal are favourable to the thermal radiation absorphon. When the wavelength of the light radiation is coupled with the wavelength of resonance absorption of the oxides, the energy of radiation may be absorbed throughout. The infrared coating materials consisting of certain oxides can make higher selective emission within a certain broad wavelength band. The infrared rediation transport increase the absorption of heat on the sarfase of the metal in the heating metal process.
Abstract: The conditions of colour reaction of calciun and DBC-chlorophosphonazo in ethanol-aqueous medium were optimized and analytical charateristics of this colour system was examied. A decomposition method and interference-free method for determination of calcium in complex Baotou iron ores were investigated. A spectophotometry with simple separation for determination of calcium in Baotou iron ores was developed.
Abstract: Based on the general objective of the development planning of teacher team, mathematical model theory is applied to the setting-up of the Management-By-Objective (MBO) system for optimizing the structure of teacher team. The quantitative control method to achieve the planned objective is obtained. The relative measures to take to promote the process of scientific manangement of teacher team are put forward.
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
