Abstract: In order to improve the efficiency of integrated impeller rough machining and make up the deficiency of commercial computer aided manufacturing (CAM) software in five-axis plunge milling, a ruled surface impeller plunge milling method was presented. Boundary vectors were generated according to an impeller’s ruled surface blade. Quaternion interpolation algorithm was used to interpolate cutter axes according to these boundary vectors. The computing formula of row spacing and stepover are deduced to ensure high material removal rate and machining efficiency. Hub surface and a blade finishing cutting path were also generated. Based on the algorithm, an integrated special impeller plunge milling CAM software was independently developed. The generated cutting path was simulated and also carried out practically. Simulation and experimental results show that this method improves the efficiency of impeller parts rough machining to a certain extent.
Abstract: The thermally coupled distillation configuration (TCDS) could reduce energy consumption and capital investment compared with conventional distillation sequences. But their use was still limited. The five kinds of conventional distillation sequences and five kinds of thermally coupled distillation sequences were performed in separation of quaternary mixtures with distillation rigorous simulations. The energy savings of a series of thermally coupled distillation sequences were compared. The results showed that the feed composition and ease of separation of the composition have great effect on the choice of the thermally coupled sequences. In the most cases, the TCDS with side rectifier or striper had the more energy saving effect.
Abstract: The DOS-coated aluminum nanopowders were prepared by using a kneader. The DOS-coated aluminum nanopowders were characterized by TEM, XRD and FTIR. The exothermic characterization of the DOS-coated aluminum nanopowders was analysized by simultaneous TG-DSC. The results show that the DOS-coated aluminum nanopowders have a core-shell structure and the release heat enthalpy in pure oxygen is 4.955KJ/g at 529.2°C. The stability of DOS-coated aluminum nanopowders excels Al2O3-passivated aluminum nanopowders due to the hydrophobic nature of DOS and the hydrophilic nature of Al2O3.
Abstract: In this paper, a summary of Genetic Algorithm methods developed recent years applied in chemical reaction kinetics was presented. The applications of the Genetic Algorithm in reduction of the chemical reaction kinetics, estimation of the chemical kinetic parameters and calculation of the chemical kinetic equations were expounded here. Eventually, the confronted problem and developing trend of the application of Genetic Algorithm methods in chemical kinetics were reviewed.
Abstract: Based on the silicate structure theory, the molten slag structure and the existential state of and during micro-carbon Cr-Fe alloy production process were analysised, and then their diffusion coefficients were calculated. The results showed that, during the initial stage, the average diffusion coeffecient of and is close to the , the reaction process is controlled by the diffusion of () and corporately, during the later stage, the diffusion coefficient of is less than average diffusion coefficient of and , the controlling step is the diffusion of . According to the evolution of diffusion coefficient, molten slag composition optimization method was advised to increase the diffusion ability of and for enhancing the reaction efficiency and the recovery rate of chromium.
Abstract: The in-plane dynamic crushing of hexagonal honeycombs was numerically studied by means of explicit dynamic finite element method using ANSYS/LS-DYNA. Under the assumption that the edge length and thickness were the same, the metal honeycomb models filled with convex and concave cells were established. And then the effects of expanding angle and impact velocity on the plateau stress and the energy absorption capacities of hexagonal honeycombs were discussed in detail. Numerical results show that the energy absorption capacities of convex hexagonal honeycombs are stronger than the concave ones. These results will provide some useful guides for the dynamic energy absorption design of cellular materials.
Abstract: The scene model is extremely complex in the 3DVR remote control platform for shearer. In order to speed up the 3D scene rendering of 3DVR remote control platform for shearer and reduce computational load of the system, we simplified the scene model based on LOD technology. The LOD algorithm was designed, in which the computing method of simplification rate, the algorithm of Triangle mesh simplification based on contraction and data structure of original mesh was described. Two shearer drums were simulated in the XNA platform via the above method. The simulation experiment results show that LOD model generated by the LOD algorithm have almost no loss in the visual effect, meanwhile the complexity of the scene model is reduced and the scene rendering speed is improved.
Abstract: To solve the information loss on the feature extraction process in the traditional fault diagnosis, this paper proposes a new method which based on probability boxes and Dempster Shafer Structure (DSS). The DSS was extracted from the raw data and then transformed into a probability box. The bearing fault diagnosis was done by the probability boxes images recognition. To solve the excessive computing cost caused by large sample frequency and the overlaps among p-boxes, the Support Vector Machine (SVM) was involved. The SVM features database was established by some cumulative uncertainty measures methods of p-boxes. The test result shows that this method is fast, not sensitive to noise and has high recognition rate with high accuracy.
Abstract: This paper studied on the industry synthesis process of anti-oxidant RD ((2,2,4- trimethyl-1,2-dihydro- quinoline polymer (C12H15N)n.n=2-4)) .The content of dimer, trimer and tetramer of RD were taken as the inspection targets, used the orthogonal design method, and take the ratios of keto-amine, the reaction time, the reaction temperatures and the ratios of catalyst acid-amine as inspect factors to optimized reaction condition. The result indicated that the best ratio of keto-amine is 6.5:1, the reaction time is 6 hours, the range of the reaction temperature is 115-120°C, the beat ratio of acid-amine is 0.2: 1 (the proportion is the concentration ratio for mole). Under the optimization conditions, the yield stability of RD.
Abstract: The most eﬀective way of determining the whole billet temperature ﬁeld is to use a simulation model. Large amount of calculation as well as computational time is consumed to employ two-dimensional finite difference method since the heating process is extremely complex, then it’s necessary to simplify the calculation process. In this paper, a simplified method in one-dimension format was presented to calculate two-dimensional heat conduction equations of heating slab. The billet simulated was placed in a changeable thermal flux boundary environment, in which the thermal flux was proportional to fourth power of temperature. During the heating process, the changeable parameters were taken into account: i. e different billet dimensions, different billet thermal conduction, different specific heat, etc. The comparision between results of two-dimensional finite difference method and the simplified method verified that the simplified method can satisfy accuracy requirement as well as calculation time saving, which enable the simplified method online using.