Influence of Asymmetric Rolling Process and Thickness Reduction on the Microstructure and Mechanical Properties of the Al–Mg-Si Alloy

Xuehong Xu,Yunlai Deng,Xiaobin Guo,Qinglin Pan 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

The influence of the asymmetric rolling process (ASR) and thickness reduction on the microstructure and mechanical propertiesof Al–Mg–Si alloys is studied. The specimens of the ASR and higher thickness reduction show higher strength (both theultimate tensile strength and yield strength) and lower elongation (El). However, both the strength and El are reduced withthe increase of the rotation speed ratio (ω1/ω2) in the specimens treated by the ASR. The grain size, density of dislocations,volume fraction of deformation texture and number density of precipitates are the main reasons causing the difference instrength and El. The increment in strength is mainly due to the increase of deformation texture, density of dislocations duringthe cold rolling and number density of precipitates formed during subsequent ageing. The reduction of volume fractionof deformation texture and number density of precipitates are responsible for the decrease of the strength in the specimenstreated by the ASR. The high-density dislocations in turn provide little room for the accumulation of dislocations and thereforereduces the EI.

Effect of moisture content on dense-phase conveying of pulverized coal at high pressure

Xu Pan,Chen Xiaoping,Liang Cai,Xu Guiling,Liu Daoyin,Zhao Changsui 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.10

In dense-phase pneumatic conveying, the solid moisture content can significantly influence the conveying process, but there are very few studies in the open literature. In this study, the conveying experiments of two pulverized coals with various moisture contents were carried out at a 4MPa high pressure and dense-phase pneumatic conveying facility. Results show that the whole conveying system can be stably and controllably operated under the condition that moisture content below ~8%. With the increase of moisture content up to ~8%, the mass flow rate of 280 μm pulverized coal increases at first and then decreases, while that of 55 μm pulverized coal decreases continuously. The method of solid friction factor correlation is used to investigate pressure drop of the horizontal pipe, and non-dimensional parameters--Fr number, moisture content M and solid loading ratio μ--are investigated. The pressure drop predictions by this correlation are in good agreement with the experimental data. The solid friction factor correlations indicate that the fine coal is more sensitive to M, and μ plays a more important role for the coarse coal.

Effects of Coated Compound Proteases on Apparent Total Tract Digestibility of Nutrients and Apparent Ileal Digestibility of Amino Acids for Pigs

Pan, L.,Zhao, P.F.,Yang, Z.Y.,Long, S.F.,Wang, H.L.,Tian, Q.Y.,Xu, Y.T.,Xu, X.,Zhang, Z.H.,Piao, X.S. Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.12

Two experiments were conducted to evaluate effects of coated compound proteases (CC protease) on apparent total tract digestibility (ATTD) of nitrogen (N) and energy, and apparent ileal digestibility (AID) of amino acids (AA) and nutrients in diets for pigs. In Exp. 1, 12 crossbred barrows (initial body weight: $20.79{\pm}1.94kg$) were housed in individual metabolism crates and allotted into 2 treatments with 6 piglets per treatment according to weight in a randomized complete block design. The 2 diets were corn-soybean meal basal diets with (0.2 g/kg) or without CC protease supplementation. The CC protease supplementation increased (p<0.05) the digestible and metabolizable N and energy values and the digestibility and retention rate of N in the diet. The ATTD of energy and nutrients had been improved (p<0.05) in the diet supplemented with CC protease. In Exp. 2, 12 crossbred barrows (initial body weight: $20.79{\pm}1.94kg$), fitted with T-cannulas at the distal ileum, were blocked by body weight into 2 groups with 6 pigs each. The diets were the same as those in Exp. 1. The CC protease increased (p<0.05) the AID of crude protein and some essential AA including arginine, isoleucine and leucine. The AID and ATTD of energy and nutrients had been improved (p<0.05) by supplemental CC protease, but the hindgut digestibility of nutrients was unaffected. Overall, the CC protease improved the ATTD of N and energy and AID of some indispensible AA and nutrients in the corn-soybean meal diet for pigs. Therefore, the CC protease supplement could improve the utilization of protein in the corn-soybean meal diet and thus contribute to lower N excretion to the environment.

Image Segmentation by Student's-t Mixture Models Based on Markov Random Field and Weighted Mean Template

Xu Pan,Hongqing Zhu,Qunyi Xie 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.2

Finite mixture model (FMM) with Gaussian distribution has been widely used in many image processing and pattern recognition tasks. This paper presents a new Student's-t mixture model (SMM) based on Markov random field (MRF) and weighted mean template. In this model, the Student's-t distribution is considered as an alternative to the Gaussian distribution due to the former is heavily tailed than Gaussian distribution, thus providing robustness to outliers. With the help of the weighted mean template, the spatial information between neighboring pixels of an image is considered during the learning step. In addition, the proposed method is able to impose the smoothness constraint on the pixel label by using MRF. Furthermore, an efficient energy function and a novel factor are applied in current model to decrease the computational complexity. Numerical experiments are presented on simulated and real world images, and the results are compared with other FMM-based models.

Synthesis and characterization of monodisperse yttrium aluminum garnet (YAG) micro-crystals with rhombic dodecahedron

Xu, Tao,Yuan, Rui,Xu, Peng-Cheng,Pan, Dong-Jie,Yang, Woochul,Guo, Hai-Bo,Shen, Yu-Fang,Hu, Jian-Feng,Zhang, Zhi-Jun,Zhao, Jing-Tai Elsevier 2018 Journal of alloys and compounds Vol.762 No.-

<P><B>Abstract</B></P> <P>Uniform, monodisperse yttrium aluminum garnet (YAG) rhombic dodecahedron micro-crystals were synthesized using coprecipitation and hydrothermal methods. The Na<SUB>2</SUB>SO<SUB>4</SUB> as a surfactant was helpful in improving the dispersity of the crystallites and forming well-faceted, micro-sized dodecahedral YAG crystallites. The effect of the reaction time and the solvent has also been studied. The crystal growth mechanism called dissolution/crystallization was determined by analyzing the experimental and simulated results. And the specific well-developed crystal facets in the {110} family have been demonstrated by the theoretical calculation. A higher integrated emission intensity can be achieved for the YAG:Ce crystallites by improving the phase purity, morphology with better developed dodecahedrons, and dispersion. Furthermore, a rather high luminous efficacy (LE = 104.14 lm/W) for the white LED fabricated using the YAG:Ce<SUP>3+</SUP> phosphor prepared in this work was realized. The correlation between the crystal growth, morphology and luminescence properties of YAG crystallites has been established, which exhibits a great importance for the synthesis and application of mono-dispersed YAG crystallites.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Uniform and monodisperse YAG rhombic dodecahedron micro-crystals were synthesized. </LI> <LI> The growth mechanism of YAG rhombic dodecahedron was studied through experimental and computational simulation. </LI> <LI> The correlation between the crystal growth, morphology and luminescence of YAG crystallites was established. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A cam-quadrilateral mechanism for power transmission of a twin-rotor piston engine

Xiaojun Xu,Hao Deng,Cunyun Pan,Haijun Xu 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.3

A quadrilateral with four invariable lengths of sides has the characteristic of transforming the variation of the diagonal length to thevariation of its interior angle. Thus, the combination of two quadrilaterals with a cam forms the differential velocity drive mechanism(DVDM) of a novel twin-rotor piston engine (TRPE). The DVDM restricts the two coaxial rotors to rotate with periodical but nonuniformvelocity, and the volume of working chambers created by the adjacent vane pistons of the two rotors alternately expands and thencontracts. The volumetric change of working chambers is used to generate the four-stroke engine cycle. The kinematic model and thedetailed position, velocity, and acceleration analysis results of the TRPE are presented. The results show that this novel engine, associatedwith the advantages of higher uniformity of torque and power density due to multiple power strokes per revolution of the output shaft, hasa compact and totally balanced design.

Molecular Mechanism and Regulation of Carotenoid Biosynthesis in Citrus sinensis

Qiang Xu,Xiuxin Deng,Qing Liu,Jiancheng Zhang,Nengguo Tao,Wenjing Zhou,Zhiyong Pan,Juan Xu 한국원예학회 2008 한국원예학회 기타간행물 Vol.- No.-

Privacy Protection for LBS in Mobile Environments : Progresses, Issues and Challenges

Julong Pan,Zhengwei Zuo,Zhanyi Xu,Qun Jin 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.1

Salvianolic Acid B Reverses the Epithelial-to-mesenchymal Transition of HK-2 Cells that is Induced by Transforming Growth Factor-β

Rong-hua Pan,Feng-yan Xie,Hui-mei Chen,Li-zhi Xu,Xiao-chun Wu,Ling-ling Xu,Gang Yao 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.3

Salvianolic acid B (Sal B) is the most abundant bioactive molecule from Radix Salviae Miltiorrhizae, and has recently been used for treating renal fibrosis in traditional Chinese medicine. Here we investigated the ability reversal of Sal B to reverse the transdifferentiation of human kidney proximal tubular epithelial cells that was induced by transforming growth factor-beta 1 (TGF-β1). The effects of Sal B on HK-2 cell morphology were observed by phase contrast microscopy, while alpha smooth muscle actin and E-cadherin were studied by immunocytochemistry and real-time reverse transcription polymerase chain reaction, respectively. Exposure of HK-2 cells to TGF-β1 for 72 h induced a complete conversion of the epithelial cells to myofibroblasts. When HK-2 cells were co-incubated with Sal B and TGF-β1 for a further 72 h, the morphology of myofibroblasts returned to that of proximal tubular epithelial cells,whereas the myofibroblast phenotype was maintained after exposure of cells to TGF-β1 for 144 h. Sal B reduced alpha smooth muscle actin levels and increased E-cadherin levels compared with their epithelial-to-mesenchymal transition controls. The reversal effect of Sal B was dose-dependent. That Sal B reverses the epithelial-to-mesenchymal transition in vitro suggests that it could possibly facilitate the repair of tubular epithelial structures and the regression of renal fibrosis in injured kidneys.

Information Dissemination Model of Microblogging with Internet Marketers

Xu, Dongliang,Pan, Jingchang,Wang, Bailing,Liu, Meng,Kang, Qinma Korea Information Processing Society 2019 Journal of information processing systems Vol.15 No.4

Microblogging services (such as Twitter) are the representative information communication networks during the Web 2.0 era, which have gained remarkable popularity. Weibo has become a popular platform for information dissemination in online social networks due to its large number of users. In this study, a microblog information dissemination model is presented. Related concepts are introduced and analyzed based on the dynamic model of infectious disease, and new influencing factors are proposed to improve the susceptible-infective-removal (SIR) information dissemination model. Correlation analysis is conducted on the existing information dissemination risk and the rumor dissemination model of microblog. In this study, web hyper is used to model rumor dissemination. Finally, the experimental results illustrate the effectiveness of the method in reducing the rumor dissemination of microblogs.