Advanced Materials Research Vols. 712-715

Abstract: [purpose] Using the liquid chromatography-Ultraviolet method ,the monosomic Ginsenosides Rb1 content is detected, and evaluated the measuring uncertainty of the monosomic Ginsenosides Rb1 content. [method] Analyzing the main source of the uncertainty components, finally evaluating and calculating the uncertainty components. [result]The results shows that, when the monosomic Ginsenosides Rb1 content is in the range of 0.02-0.12mg/ml, there is a good linear relation, and the linear equation is A=13651.52c+0.1430, r=0.9999 (coefficient correlation) For example, when the content of monosomic Ginsenosides is 0.3421%, the expanded uncertainty of monosomic Ginsenosides measurement is U=0.0236%(K=2). [conclusion]This study provides a reliable theoretical basis for the effective controlling the quality of monosomic Ginsenosides Rb1 content measurement.

Abstract: First-principle software bundle based on the density functional theory (DFT) is used to investigate pure CeOB_2B and Mn-doped CeOB_2B with different doping concentration. The structural model of CeOB_2B crystal is constructed and geometrically optimized, the electron density of states and band structure calculated. The results are as follows: the valence band top of CeOB_2B is made up with O2p and Ce5d states, and the existence of 4f unoccupied molecular orbital of CeOB_2B facilitates the electronic storage. The theoretical calculation models of Mn-doped CeOB_2B with different concentration are constructed and calculated, including 2*1*1, 2*2*1 and 2*2*2 supercell models. After CeOB_2B is doped, hybridization happens between 4s orbitals of Mn atoms and 2p orbital of O atoms, resulting in 4s orbitals of Mn atoms lose electrons.Moreover, Mn atom is electron donor and O atoms is the electron acceptor. As the doping concentration decreases, the formation energy also decreases.And a smaller formation energy leads to a more stable structure.

Abstract: The structural feature and technical indexes of 2A14 aluminum alloy connecting rod was analyzed. The pouring system of gravity die-casting process was initially designed according to the technical requirements. The gravity filling and solidification stages in the permanent mold were simulated by ProCAST. The simulation results show that the casting defects are predicted and the casting process are improved. The most possible section of crack defects are the transition part between the shaft and the connecting rod small or big end.

Abstract: In this paper an efficient grinding mode which is employed by the Cranfield BoX ultra precision grinding machine is discussed. The equations of workpiece surface and grinding wheel surface are proposed and the grinding motion is simulated via Matlab. The trajectory of the changing cutting region is discussed. The simulation results show that this grinding mode is suit to manufacture low slope surfaces. Generally, the workpiece surface is steeper, and the cutting range of the machine is smaller. The angle of the spindle inclination, the grinding wheel width and the cutting depth should be chose properly for different manufacturing capacity.

Abstract: The Copper-bearing minerals Powder (≤2mm) is used in conical ball grinding, the experimental study shows that the effect of the three kinds offactors on grinding efficiency is obvious. In this paper, we will start from the pulp rheological perspective to discuss why this is. In the end, the optimal conditions include the best pulp density 70%, the best mill speed 86.33r/min and the best time 4 min.

Abstract: This paper presents some cutting methods used in offshore structural member removal which be different from the traditional machining method used in forming a part. The author collects three species of cutting techniques which classified by energy and tools. A catalogue from the practical engineering application is listed, so as to give a better understanding of their characters. The author also gives detailed description of cutting techniques used in offshore steel structural below. And case study of cutting method is given to illustrate the application of it. The study in this paper makes the important reference for practical engineering application of offshore engineering.

Abstract: According to process requirements of edge rolling in roughing stage of continuous hot strip rolling, common methods of short stroke control were analyzed. A 3D elastic-plastic FEM model for roughing stage of continuous hot strip rolling was established using ABAQUS/Explicit, and research on deformation law of plate head and tailwidth lossin different working conditions was done. Besides, control effects of broken line SSC method and polynomial SSC method were analyzed. On the basis of them, a new polynomial SSC model was established. The model is effective in controlling width loss of plate head and tail and is beneficial to improve the quality of plate in some degree.

Abstract: Micro machining becomes more and more important with the tendency of miniaturization of components used in various fields from military to civilian applications. The finite element method software Abaqus is used to model the nonlinear thermal force coupled elastic-plastic micro machining processes. Relatively systematic simulation analysis has been introduced based on the model combining the Johnson-Cook failure criteria, element deletion strategy etc. It reveals that the size effect is dominant while the depth of cut reaches the cutting edge radius. The rake angle plays more important roles on the micro machining than that of the cutting speed.

Abstract: Chemical mechanical grinding (CMG) was applied in machining K9 optical glass. Eight types of CMG wheels were developed and their dry grinding performances were analyzed. The specific CMG wheel which contained 28%vol.abrasive,20%vol.porous and certain additives obtained satisfied surface quality and material removal rate, as result that the solid state reaction and mechanical elimination reached equilibrium. The CMG process parameters, including pressure, workpiece speed and wheel speed, were optimized by using orthogonal experimental method. The surface roughness can reach 0.461nm in Ra on the basis of optimized processing parameters.

Abstract: The basic principle and the characteristics of magnetically controlled welding technology are introduced in this paper. The specific applications of domestic and foreign magnetically controlled welding technology in welding process are comprehensively analyzed at the moment, including the effect rule of external magnetic field on arc shape, metal droplet transfer, molten pool, weld microstructure, mechanical properties. And the key problems needing to be solved are deeply investigated. The developments of magnetically controlled welding technology in the future are also forecasted.