Abstract: A 3D visualization system for mineral deposits is an important means to understand the spatial distribution of mineral grades, and a fundamental tool for computer-aided design and planning of mines. Some 3D visualization techniques for modeling mineral deposits were presented and a framework for building a 3D visual modeling system of mineral deposits was proposed. Based on Windows, VC++ IDE and OpenGL, a prototype 3D visualization system for modeling mineral deposits was developed. Real data from a Chinese underground iron mine were used to verify the system prototype and the resulting 3D images of boreholes and orebodies were satisfactory, depicting a simulated true picture of the mineral deposit, which demonstrated the effective and efficiency of the visualization system.
Abstract: An OpenGL based 3D visual modeling system of underground mine excavations was introduced. The key techniques for developing the 3D visual modeling system with OpenGL were presented, including entity drawing, geometric transformation, projective transformation, illumination and rendering. The examples of OpenGL application were given and a prototype system for visualizing the underground mine excavation system of a Chinese iron mine was characterised. Some problems for further study were proposed.
Abstract: Most of large and middle scale open-pit mines in China have reached deep mining. Along with the deeping and steepening of the slope, the difficulty to maintain stability of the slope and the probability of failure of the mining area are getting large and large. Due to complicated burring conditions of the ore-bodies in the open-pit mines, the failure modes of the slope are closely related to geological structures and rock mass characteristics. Through systematical field investigations, tests and studies, the tectonic features and general conditions of engineering geology, the mechanisms and modes of failure of the slope in Shuichang mine are basically understood. A geological model of the high and steep slopes in Shuichang open-pit mine is established, which provides a strong basis for stability analysis and optimum design of the slopes using numerical modeling and limiting equilibrium analysis methods.
Abstract: Shuichang open-pit iron mine in China was taken as the engineering project of the study. Based on systematical investigation and study of engineering-geological conditions, rock mass structures, hydro-geological and permeability field conditions, in situ stress measurement, physical and mechanical property tests of rock mass, the stability analysis and design optimization of the slope for Shuichang open-pit mine were completed. Through the study, the overall slope angle for every sub-zones is increased 1-6°.
Abstract: A free cutting steel containing tin less than 0.05% in mass fraction was developed, which possessed good machinability and satisfactory mechanical properties meeting the national standard of China. The forms and distribution of inclusions and tin in the steel were investigated by observations of the steel samples and the fracture of the mechanical testing samples by means of SEM and EDS. The results showed that the complex inclusions, nodular or spindle-shaped, were composed mainly of oxides and manganese sulphide. It was found that there were marked segregation of tin in the fracture and on the surfaces of inclusions in the steel.
Abstract: The thermotropic phase transitions in the perovskite type-layer compound (n-C10H21NH3)2ZnCl4 and (n-C12H25NH3)2ZnCl4 were synthesized and a series of their mixtures were prepared from ethanol solutions. Nonisothermal kinetics of solid-solid phase transitions in C10Zn, C18Zn and their binary system was investigated by DSC. Kissinger and Ozawa methods were applied to determine the activation energy and reaction order of the solid-solid transitions. The results of two methods are in agreement.
Abstract: In the experiment, HRB335 steel was treated by impulse current, and the maximum current, frequency and processing time were considered together. The optimal result is the following: the current density is 0.021~0.025 A/mm2, the frequency is 1 Hz and the processing time is 30 s or so. The maximum equiaxial crystal ratio is up to 95% and the crystals are obviously refined. Compared with the others' discoveries the primary inclusion was made that electropulse effect may be independent of steel species. Different opinions about the columnar crystal broken theory were proposed. It is considered that liquid level fluctuation phenomena are for too much oxygen is dissolved into the metal.
Abstract: The vacuum melting and argon protecting continuous unidirectional solidification technology was introduced, which combined vacuum inductive melting with continuous unidirectional solidification. Integrating melting, purification and solidification, the system has convenient control, strong ability to mix and oxidize and higher efficiency, and can produce pure and high-class materials with unidirectional microstructure. A Cu bar of 8 m in length with columned crystals, was made with self-made equipment based on the technology and its microstructure and properties were analyzed.
Abstract: Perovskite synroc samples were synthesized by Self-propagating High-temperature Synthesis (SHS), and their properties, including leach rate, density, microhardness and the largest High Level radioactive Waste (HLW) content held in the samples, were tested by X-ray diffraction and scanning electron microscopy. The results indieate that the Sr2+-CaTiO3 compound with high density are formed and the largest SrO content in the compound can reach 35% in mass fraction. It can be concluded that the perovskite synroc is a perfect material to immobilize HLW.
Abstract: Cu40Ti60-xZrx (x = 0,10,30,50) amorphous alloys were fabricated successfully by using mechanical alloying method. The mechanism of amorphization was discussed by investigating the transformation of Cu-Ti-Zr alloy powders from crystallization to amorphous state in the process of mechanical alloying. The thermal stability and crystalline phase of amorphous alloys were also investigated. It is shown that the amorphous is formed from the original elements directly, and no metallic compounds appear in the solid-state reaction. The amorphization mechanism may be explained by the vacancy diffusion model. The DSC traces of fully amorphous Cu40TixZry powders show that the onset crystallization temperature (Tx) is increased with the decrease of Ti content and the increase of Zr content. The Cu40Ti30Zr30 and Cu40Ti10Zr50 amorphous alloys were annealed near the onset crystallization temperature, Tx. It is found that Zr2Cu, Cu4Ti and a little unidentified crystal phases were precipitated in the Cu40Ti10Zr50 amorphous alloy after annealed for 15 min, whereas there were no precipitates in the Cu40Ti30Zr30 amorphous alloy.
Abstract: Limiting current oxygen sensors with LSCo as dense diffusion barrier and Yttria (8% in molar fraction) Stabilized Zirconia (YSZ) as oxygen ion conduction solid electrolytes was developed through an effective technology. This type of sensor can get stable current plateau in whole range of air-fuel ratio. Compared with existing limiting current oxygen sensors, it has a simpler design, a faster response and lower cost, thus has a good application.
Abstract: Based on the theory of static magnetic field, the surface magnetic field on the high-resolution multi-pole magnetic drum for a magnetic rotary encoder was analyzed. The visual curves of the surface magnetic field distribution were obtained by numerical calculation and plotting. A good AMR magnetic head for the magnetic rotary encoder was designed. The results of theoretical analysis and practical test were contrasted. The results are accorded in the output signal's shape and amplitude of the AMR magnetic head and its multi-frequency characteristic.
Abstract: The effects of single solid solution treatment and two-stage solid solution treatment on the micro-structure and mechanical properties of spray deposited Al-Zn-Mg-Cu aluminum alloy were investigated. The micro-structure and precipitation were observed by optical microscopy, SEM and TEM. It is shown that the microstructure and mechanical properties by the two-stage solid solution treatment is better than those by the single solution treatment. The two-stage solution treatment has the advantages of low and high temperature single solution. After the two-stage solid solution, recrystallization grains did not grow up and most of precipitation were dissolved. The tensile strength and the yield strength of the alloy can reach 806 and 797 MPa respectively with a elongation of 7.5% after the two-stage solid solution and the T6 aging treatment.
Abstract: The microstructure evolution of Q235 plain carbon steel in multi-pass hot deformation was investigated by means of hot compression simulation. The results indieate that fine ferrite grains of 4-5 μm can be achieved by deformation enhanced phase transformation of undercooled austenite in combination with austenitic recrystallization. The yield strength exceeded 400 MPa and the plastic elongation was over 40%. By proper heat treatment after deformation the scattered minor microstructures of cementite and pearlite were distributed on the grain boundaries of fine ferrite grains. The yield ratio was effectively decreased without loss of yield strength and the ductility.
Abstract: The microstructure evolution of undercooled austenite to ferrite in a low carbon steel during deformation at 760℃ and strain rates of 1 s-1 and 10 s-1 was investigated. The results show that the true stress-strain curve at 1 s-1 demonstrates two peaks, indicating Deformation Enhanced Ferrite Transformation (DEFT) and ferrite dynamic recrystallization involved respectively. More pronounced ferrite refinement is achieved at 1 s-1 because of the restriction against grain growth both in the two aspects of time and space of the new ferrite grains nucleating repeatedly and rapidly chiefly at the front of the phase boundaries between ferrite and austenite. As the strain rate increasing to 10 s-1, the true stress-strain curve demonstrates only one peak indicating DEFT involved mainly because of the acceleration of transformation kinetics. In addition to the phase boundaries above-mentioned, ferrite nucleates in the intragranular of austenite, which weakens the restriction against grain growth somewhat and ferrite grain size become coarsening slightly. Based on the theory of DEFT and ferrite dynamic recrystallization, ultra-fine ferrite structure with grain sizes of about (1.98 ±1.07) μm and (2.33 ±1.01) μm was formed at strain rates of 1 s-1 and 10 s-1 respectively.
Abstract: Compression tests were conducted with as-cast Ti45A18Nb2Mn0.2B alloy at strain rates of 1-10-3/ s at temperatures of 900-1200℃. Deformation processing and microstructure changes were analyzed. It is found that the strain-rate-sensitivity coefficients range from 0.10 to 0.24 at the test temperatures. The true stress-true strain curve shows a peak stress, then the flow stress decreases into a steady value with the increase in stain. Dynamic re-crystallization occurs in the alloy during the high-temperature deformation and considerable microstructure refinement is achieved. The recrystallized grain size decreases with the decreasing of compression temperature and the increasing of strain rate, that is, with the increase of Zener-Hollomon parameter. Recrystallization processing can be promoted with the increasing of temperature and the decreasing of strain rate.
Abstract: The effects of NaCl and SO2 on the initial atmospheric corrosion of AZ91D magnesium alloy were studied with a simulated atmospheric corrosion system. The analyses of surface morphology, corrosion products and rust layer structure were integrated by Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) to investigate the corrosion performance. The results showed that NaCl accelerated the initial atmospheric corrosion of the alloy. The protective film was destroyed in the initial period, but the corrosion rate slowed down because of the formation of slight soluble corrosion products in the later periods in the presence of NaCl. Soluble corrosion products with no inhibitive function developed and partly solved to form the ions of free motion when NaCl and SO2 existed simultaneously. A great deal of these products were very difficult to grow on the surface in a short time. The combined effect of NaCl and SO2 on the initial atmospheric corrosion was greater than that caused by each single component.
Abstract: Corrosion behaviors of X70 steel in the environments of Ku'erle soil corrosion station, soil saturated with water and simulated soil solution were studied by means of macroscopical observations, SEM, EDS, XRD, weight-loss method etc. The results reveal that the ranking of corrosion rate from the biggest is simulated soil solution, Ku'erle field soil, and soil saturated with water. It can be explained that the occurrence of microbiologically influenced corrosion leads to a high corrosion rate of X70 steel in Ku'erle field soil. In soil saturated water, water reduces the permeability of air, and soil blocks the ion exchange of X70 steel, which result in a low corrosion rate. In simulated soil solution, electrochemical reactions are easiest to take place, so the corrosion rate is the highest.
Abstract: The four-point bending (4PB) test of notched specimens made of a low alloy steel (WCF-62) was carried out at different loading rates at -100℃. The local cleavage fracture stress σf was measured. The Influence of loading rate on fracture behavior of the notched specimens was investigated. It is found that at a low loading rate v≤10 mm/min, σf is about 1100 MPa, while at a high loading rate v ≥ 120 mm/min, σf is about 700 MPa. The change of σf is caused by the change of critical events with loading rate, and if the critical events are identical, σf does not vary with loading rate. When the loading rate is about 30 mm/min the notch toughness decrease sharply with the rising of loading rate due to an abrupt change of σf.
Abstract: Using the software MARC/AutoForge 3.1, a three-dimensional thermo-mechanical coupled elasto-plastic Finite Element Method (FEM) was used for the simulation of a two-pass tube tension-reducing process of 33Mn2V steel for oil well tubes. The simulated results intuitionally visualize the metal flow and dynamic evolution of strain, stress and temperature, especially inside the work-piece, and show that their non-uniform spatial distributions on the longitudinal and transverse sections are a distinct characteristic of the tube tension-reducing process.
Abstract: Aiming at H-beam straightening, the plastical deformation of H-beam flange should be occurred when the rollers pressed the web plate. In order to avoid flaws in the process of H-beam straightening, an adequate mechanical model was established and the relations between bending moments, forces and bending deflections of the H-beam in nine-roller straightening were deduced. The range of the technological parameters such as forces and bending moments under each straightening roller was determined by adjusting the bending deflections in practice.
Abstract: In the flatness control system of hot strip, measured flatness signals usually contains additional signals caused by temperature difference along the lateral direction of the hot strip after rolling. The lateral temperature of the hot strip was measured by a kind of thermovision in ASP 1700 hot strip mill in AnSteel, China. By analyzing the influence of the temperature difference on the flatness control system of hot strip, the lateral temperature field distributing law was obtained based on the least square method and a temperature compensating model for the control target of strip flatness was set up at the same time.
Abstract: The real-time online monitoring system of displacement of the end of rolled parts in Multi-wedge Cross Wedge Rolling (MCWR) was developed. It can measure the movement of the end of workpieces exactly in the course of single-wedge cross wedge rolling and MCWR. The regularity of movement of the end of workpiece was discovered by analysis in detail. The theoretical result is in agreement with the testing, with the error less than 17%, which demonstrates the accuracy and reliability in movement of the testing system.
Abstract: Based on analyzing some drawbacks of existing distributed remote diagnosis systems, a POA policies model is presented according to CORBA's specification. Some key technologies for POA policies and their optimizing methods are discussed, and the usage of the POA policies model in distributed remote diagnosis systems is focused on. Most of the functions discussed here have successfully used in industry.
Abstract: Artificial life enhances the reality and vitality of computer animation. To control the process of animation and instruct the action of characters in animation, artificial intelligence is introduced in computer animation. Cognitive models based on self-reproduction are presented and built to improve the cognition of artificial fish, and high-level motion controls based on animal logic are implemented. Deterministic behavior models on copulation, spawning and environmental selection of artificial fish are built. It is shown by experiments that a high-level motion controller makes artificial fish adapt the virtual environment of sea and complete the process of life such as copulation, spawning, etc.
Abstract: The traditional web-based community service cannot realize resource sharing, as society resources are distributed and community services are dynamic and heterogeneous. This paper presents a virtual community service architecture based on the Open Grid Service Architecture (OGSA). A stochastic high-level Petri net model is given to realize the Quality of Service (QoS) based scheduling of community service resources.
Abstract: In current researches of knowledge discovery, inconsistent examples in a decision table are not be analyzed. It is just the place that contradictions would hide interesting and valuable information. An algorithm based on the support vector machine is proposed to mine kinds of information which hide in inconsistent examples, i.e., to decide whether inconsistency is caused by mistake, the error between a computed or measured value and a true or theoretically correct value, or missing attributes. Some methods and algorithms which eliminate the inconsistency are presented.
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
