关键词：
phase field models;second phase particles;grain growth;magnesium alloy
摘要：
Phase field models were established to simulate the grain growth of a nanostructured AZ31 magnesium alloy, which contain spherical particles of differing sizes and volume fractions, under realistic spatial and temporal scales. The effect of the second phase particles on the nanostructure evolution was studied. The simulated results were compared with those of the conventional microstructured alloy. The expression of the local free energy density was improved by adding a second phase particle term. The right input parameters were selected for proper physical meaning. It was shown that the rules that govern the pinning effect of the second phase particles during the grain growth were different for the nanostructure and microstructure. There was a critical particle size value that affected the grain growth within the nanostructure. If the particle size was lower than the critical value, the pinning effect on grain growth increased with decreasing particle size. When the particle size was greater than the critical value, the particles had almost no pinning effect. However, in the conventional microstructured material, the larger particle size resulted in an enhanced pinning effect during grain growth for particle sizes smaller than 1 μm. The effect was reversed when the particle size was larger than the critical value. For the nanostructure, the critical value was 200 nm when the particle content was 10 v.%, and the critical value decreased when the content increased. When the particle size was 30 nm, the particle pinning effect on the grain growth increased for increasing particle content.
摘要：
Material Studio软件中的CASTEP模块在构建晶体结构过程中融入了基于密度泛函理论的第一性原理赝势方法。本文利用CASTEP软件包模拟研究了不同原子比的碳化钛的结构,构建了非化学计量比的Ti C0.75的晶体结构模型。如何利用CASTEP软件构建非化学计量比的晶体结构在其他文献中是比较少见的。通过对Ti C0.75晶胞结构参数及能带-态密度图的分析,得到碳含量变化对碳化钛的物理和化学性能的影响结果规律,其结果与相关文献报道一致。
会议名称：
Joint International Conference on Social Science and Environmental Science (SSES) / International Conference on Food Science and Engineering (ICFSE )
摘要：
This study aimed to analyze peanut oil adulteration based on chemometrics combined Raman and near-infrared (NIR) spectrum. The spectral data of 134 adulterated oil samples were collected by laser Raman and NIR spectrometer. The Raman spectra data and NIR were preprocessed respectively by different preprocessing approaches. The backward interval partial least squares (BiPLS) method was applied to extract the featured wavelengths. Based on the full spectrum and the characteristic wavelengths, adulteration quantity prediction models were established by the support vector machine regression (SVR) method. According to the analysis, the SVR model could predict the adulteration content in the peanut oil. Furthermore, the correlation coefficient R was greater than 0.97, and the mean square error (MSE) was smaller than 3.2E-4. The SVR model had advantageous properties such as strong generalization ability and good prediction accuracy. The results showed that Raman and NIR fusion analysis was effective in the quantitative analysis of the adulteration in peanut oil. Multi-spectral analysis for edible oil adulteration is an important field of study.
作者：
Liu, M.;Li, J. Y.;Ma, Y.;Yuan, T. Y.;Mei, Q. S.*
期刊：
Surface and Coatings Technology,2016年289:94-100 ISSN：0257-8972
通讯作者：
Mei, Q. S.
作者机构：
[Mei, Q. S.; Liu, M.; Yuan, T. Y.; Ma, Y.] Wuhan Univ, Sch Power & Mech Engn, Wuhan 430072, Peoples R China.;[Li, J. Y.] Wuhan Polytech Univ, Sch Mech Engn, Wuhan 430023, Peoples R China.
通讯机构：
[Mei, Q. S.] W;Wuhan Univ, Sch Power & Mech Engn, Wuhan 430072, Peoples R China.
关键词：
Surface nanocrystallization;Ti6Al4V alloy;Microhardness;Thermal stability;High pressure surface rolling
摘要：
Ti6Al4V alloy was subjected to high pressure surface rolling (HPSR) deformation. Effects of initial microstructure (heat treatments) and HPSR parameter on the formation of surface nanostructure and mechanical property of Ti6Al4V were investigated. A gradient nano-microstructured surface layer was successfully produced on Ti6Al4V after HPSR, of which the thickness increases and the grain size decreases with the increase of HPSR load (F). Microhardness of HPSR samples increased with decreasing depth from the treated surface, and increased with the increase of F. Microstructure of the original sample including the morphology and size of the alpha and beta phases was found to have evident effect on the thickness, grain size and microhardness of the surface deformed layer produced by HPSR. The HPSR sample showed good thermal stability after annealing at 700 degrees C for 1 h. The present results indicated that HPSR can be used as an effective method for controlled" production of gradient surface nano-microstructure on Ti6Al4V alloy with enhanced property. (C) 2016 Elsevier B.V. All rights reserved.
摘要：
Automatic dumpling forming machine is also called dumpling machine, which makes dumplings through mechanical motions. This paper adopts the stuffing delivery mechanism featuring the improved and specially-designed vane pump casing, which can contribute to the formation of dumplings. Its 3D modeling in Pro/E software, machining process planning, milling path optimization, simulation based on UG and compiling post program were introduced and verified. The results indicated that adoption of CAD/CAM offers firms the potential to pursue new innovative strategies.
