Abstract: An investigaton on in-situ indicated that the failures of button bits were obviously controlled by their weares. Based on above investigation, a few basic relations between the wear volumes of tungsten carbide bit buttons and move speeds, between bit lives and button weares, etc were obtained. The investigated results showed that weares of bit buttons affected not only bit lives but drilling efficiency, and the trimming for used bits increased not only bit lives but drilling velocity.
Abstract: The bottom-blowing experiment with CO2, N2, CO2+N2 and CO2+Ar in 60kg combined blown converter has been conducted. By comparing each experimental results, the metallurgical character of bottom blowing different gas is studied. The effect of different gas on the bath oxidation, decarbu-rization and behavior of nitrogen is mainly discussed.
Abstract: On the basis of economics, the life cycle costs of energy system are analysed, and the optimum designing and management method for energy system according to its minimum life cycle costs or maximum life cycle economic benefits is proposed.
Abstract: The simulation process of rolling deformation in matels is analysed, and a new deformation model (PC-model) is suggested. The new model modifies the shear condition of deformation grains in polycrystal, in which the shears are partially free, so that the simulation could further approach the real cases. According to comparison with rolling texture in Al polycrystal the PC-model could show more accurately the flow tendency of grain orientations in f.c.c matels and their final stable positions in orientation space.
Abstract: The quantitative analysis on austenitic grain size and undisolved carbide of M2A1 and M2 high speed steels undergone once and twice quenching indicated that two types of growth, i.e. the normal (homogenious) and abnormal (hetogenious) growth happened upon the same condition of r/f ratio at high temperature depending on initial structure before quenching. A “continious-disco-tinious” recrystallization model and a “merge-migration” growth mechanism had been proposed based on the structure abservations in the beginning of abnormal coasening. Therefore the technical priciples for reducing or eliminating the mixed grain tendency of M2A1 steel was provided.
Abstract: Based on the observations of TEM, a microstructural model of Sintered NdFeB magnets has been found. The coercivity of the model was calcu-latedbased on micromagnetic theory and the coercivity of both Nd2Fe14B grains and sintered NdFeB magnets were analysed and discussed. A magnetic hardering theory of epitaxial layer of Nd2Fe14B grain and the way of increasing coercivity of sintered NdFeB magnets were put forward.
Abstract: The bending strength and abrasion resistance of diamond layer of Si-Ti-B doped diamond/cemented carbide composites depend on both the diamond particle size and the dopant content. The relationships between the mechanical properties and the diamond particle size, dopant content are considered as the relationships between properties and the mean free path. A maxi-mun was found in the bending strength (or abrasion resistance) vs. mean free path plot. The bending strength decreases with decreasing mean free path (binder layer thickness) to the direct contact of diamond particles. The bending strength decreases with increasing binder layer thickness is attributed to that the strength and hardness of binder (SiC, TiC) are lower than that of diamond. The heat-resistance of Si-Ti-B doped diamond is higher than that of cobalt bonded diamond.
Abstract: The work, tests 14 pole figures for steel sheet under some strain paths, i.e. tension, equibiaxialstretching, uniaxialtension-equibiaxialstretching and equibiaxialstretching-uniaxialtension, and different strains. Texture influence on forming limit is discussed.
Abstract: The radical concepts of engineering stochastic optimization are introduced and a method for solving uncertain problems is developed according to the satisfied estimation of probabilistic values to stochastic constraints and the use of a quasi-gradient searching direction. The method is applied to engineering designs with linear or nonlinear stochastic constraints.
Abstract: The equilibrium constant of Mg-O in Nickel melt at the temperature range of 1 480℃ to 1580℃ was determined with the vapour equilibrium method in a sealed chamber. The influence of the alloying elements Fe, Al and Cr on the activity of Mg in nickel melts at 1480℃ mas investigated. It was found that at 1480℃ to 1580℃: $\log {K_{{\rm{MgO}}}} = 0.50 + 1.27 \times {10^4}/T;G_{{\rm{MgO}}}^{\rm{o}} = 2.43 \times {10^5} - 9.57T({\rm{J/mol}});e_{\rm{Mg}}^{{\rm{O}}} = 1.10 \times {10^3} - 2.19 \times {10^6}/T$; And at 1480℃: $e_{{\rm{Mg}}}^{{\rm{Fe}}} = - 0.28;e_{{\rm{Mg}}}^{{\rm{Al}}} = - 0.51;e_{{\rm{Mg}}}^{{\rm{Cr}}} = 0.72$
Abstract: A kind of digital signal processing method for dectecting the roll eccentricity signal is presented in light of the characteristics of roll eccentricity, and the application of this method in roll eccentricity control is discussed. The spot experimental result shows that this method is convenient in realization, accurate in processing and effective in control.
Abstract: A biomedical circulatory system is thoroughly analysed by means of Petri method. Then the states and methods for analysing this discrete event system are presented. In the end, a biomedical circulatory real time control system is implemented on a micro-computer.
Abstract: The necessity and possibility of applying computer simulation in logistics systems analysis are expounds. The principle and characteristic of logistics systems computer simulation are discussed. The general simulation program of logistics systems （GSPLS） and two practical examples applying GSPLS are introduced.
Abstract: The micro Components formed anodic films on Al were studied by ultrathin section technology, TEM, SEM etc. The results show that after 4 min of cold sealing, Ni(as a sealing agent) can be found near the outer layer, surface layer and the deep place of the anodic films. Its relative content increases to 9.244%. The content of Tin (as a coloring agent) can reach to 20.42% in the deep places of the films, while the content of S in the same place decreases from about 5% to 3%. After 100 min of cold sealing, the films on Al are still amorphous substance.
Abstract: The alternate immersion following a prescribed cycle of samples was carried out by means of a micromotor controlled by integrated circuit. The design of this instrument was described and the effect of rare earths on the resistance to atmospheric corrosion of steel 09CuPTiRE was checked. It was shown that the rare earths in steel effectively enhance the resistanc to atmospheric corrosion when it's content in steel is above around 0.012%.
Abstract: The corrosion velocities of the cold-rolling strips of Pb, Sn and their alloys were investigated by the use of methods of the weight increase and AES longitudinal spattering. The parabolic relations of the corrosion velocity for the lead were obtained under the room temperature and atmosphere, of dryheating air 155℃ or water vapor at 100℃. Similar relations for Tin and Pb-Sn alloys were obtained in the atmosphere of watar vapour at 100℃. At the sametime the data on the thickness of the corrosion layers of the alloys and the metals in the dry-heating air at 155℃ for 288 h and in the atmosphere at the room temperature for two and a half years were also obtained.
Abstract: The optimum conditions for extraction chromatography using 2ethyl-hexyl 2-ethylhexylphosphonate resin to separate thulium, yetterbium and luticium were studied. According to the proposed procedure, several grams of yetterbium oxide （purity = 99.95%） and luticium oxide （purity = 99.90%） were separated from the mixed heavy rare earth oxides on laboratory scale. Their relatively high recoveries （99% and 95% for Yb2O3 and Lu2O3 respectively） may be satisfactory.
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
