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Re-reddening on Strip Surface After Water Cooling

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Journal of Iron and Steel Research International 2007年第3期14卷 26-29,55页

作者： ZHI Ying LIU xiang-hua WANG Guo-dong State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China

After water cooling, there is a big temperature difference between the center and the surface of strip, which leads to the heat transfer from the center to the surface, and the surface temperature can rise in a short time. The finite element method was used to simulate the phenomena of re-reddening on the surface of strip and to analyze the temperature field of hot roiled strip during laminar cooling, and the periodical variation curve of the cooling rate was obtained during water cooling and subsequent re-reddening. The results show that the critical line of the cooling rate is at 1/3 of the half-thickness from the strip surface. The regression model of the relation of rereddening temperature, time, and distance from the surface was obtained in the re-reddening region. Re-reddening regularity on the surface of strip under the condition of different thickness and cooling rate was also studied.

关键词： temperature field re-reddening laminar cooling cooling rate hot rolled strip finite element method

Analysis of Crack Tip Stress of Transversal Crack on Slab Corner During Vertical-Horizontal Rolling Process by FEM

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Journal of Iron and Steel Research International 2008年第3期15卷 19-26页

作者： YU Hai-liang LIU xiang-hua WANG Guo-dong The State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China

Behavior of transversal crack notched on slab corner during vertical-horizontal rolling process was simulated by FEM. The crack tip stress in the whole rolling process was obtained. Influences of the friction coefficient, the initial crack size, the edger roll profile, and the groove fillet radii of grooved edger roll on crack tip stress were analyzed. For vertical rolling, the tension stress appears at crack tip near the slab top surface and the compression stress appears at crack tip near the slab side surface for the flat edger roll; however, the compression stress appears at crack tip near the slab top surface and the tension stress appears at crack tip near the slab side surface in the exit stage for the grooved edger roll. For horizontal rolling, the tension stress appears at crack tip just at the exit stage for the flat edger roll, and the tension stress appears in whole rolling stage; the tension stress value near the slab side surface is much larger than that near the slab top surface for the grooved edger roll.

关键词： transversal crack vertical-horizontal rolling process crack tip stress FEM

Transient small bowel angioedema due to intravenous iodinated contrast media

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World Journal of Gastroenterology 2012年第9期18卷 999-1002页

作者： Xiu-hua Hu xiang-Yang Gong Peng Hu Department of Radi-ology Sir Run Run Shaw Hospital Zhejiang University Schoolof Medicine Hangzhou 310016 Zhejiang Province China

Three cases of transient proximal small bowel angioedema induced by intravenous administration of nonionic iodinated contrast media (CM) are *** tomography (CT) images in the venous phase displayed the proximal small bowel with circumferential thickening of the wall including the duodenum and proximal segment of the *** bowel wall was normal in non-enhanced images,and normal or inconspicuous in arterial phase enhanced *** one of the three cases,the bowel wall was thickened in venous phase but disappeared in the 40 s delayed phase *** filling defect was seen in the lumen of the superior mesenteric artery and *** peritoneal effusion or mesentery abnormality was *** of these patients reported only mild abdominal discomfort and recovered without specific treatment within a short *** one patient suffered mild diarrhea after scanning which had resolved by the following *** transient anaphylactic small bowel angioedema due to intravenous iodinated contrast media was easily diagnosed based on its characteristic CT findings and clinical *** diagnosis may include inflammatory and ischemic bowel disease,as well as neoplasms.A three-phase CT protocol and good under-standing of this disorder are fundamentally important in the diagnosis of this *** supposed etiology behind the transient anaphylactic reaction to intravenous administration of iodinated CM in small bowel is similar to other CM-induced hypersensitive immediate *** predilection location of transient anaphylactic bowel angioedema is the small intestine,particularly the proximal segment.A speculated cause may be the richer supply of vessels in the small intestine,ample mucous folds and loose connective tissue in the duodenum and the jejunum.

关键词： Bowel angioedema Bowel thickening Com-puted tomography Contrast media Small bowel ana-phylaxis

Separation of growth-stimulating peptides for Bifidobacterium from soybean conglycinin

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World Journal of Gastroenterology 2005年第37期11卷 5801-5806页

作者： Wei-Yong Zuo Wei-hua Chen Si-xiang Zou Key Laboratory of Animal Physiology and Biochemistry Ministry of Agriculture College of Veterinary Medicine Nanjing Agricultural University Nanjing 210095 Jiangsu Province China

AIM： To isolate and identify the soybean conglycinin peptides that selectively stimulates the growth of bifidobacteria in vitro, and to investigate the effect of soybean conglycinin peptides on intestinal ecosystem in vivo. METHODS： Soybean conglycinin was purified from soybean seeds by gel filtration （Sepharose-CL-6B）. These proteins were submitted to hydrolysis by pepsin. Several growth-stimulating peptides for bifidobacteria were isolated chromatographically from pepsin hydrolysis of soybean conglycinin and identified by means of matrixassisted laser desorption ionization time of flight mass spectrometry （MALDI-TOF-MS）. Parallel to in vitro study, in vivo experiments with soybean conglycinin peptides were performed in mice. Ninety male KM mice were randomly assigned into five groups of 16 mice each, and each group was administered for 21d intragastrically with physiological saline （control）, conglycinin, pepsin-treated conglycinin （PTC）, the most active fraction which isolated from pepsin-treated conglycinin （P2-PTC） and HCl-full hydrolysis of conglycinin （HCl-FHC）, respectively. Intestinal microflora were evaluated by standard microbiologic methods and biochemical assays of cecal content samples after treatment. RESULTS： The results showed that the peptides which were isolated from soybean conglycinin could stimulate the growth of bifidobacteria in vitro, and the molecular mass of purified peptides with MALDI-TOF-MS ranged from 693.32 to 1829.55. Compared with control group, in vivo experiments showed that P2-PTC group decreased cecal pH （7.08±0.08 vs7.21±0.09, P〈0.05） and enterococcicounts （5.38±0.26 log10CFU/g vs 5.78±0.19 log10CFU/g, P〈0.05）, significantly increased sIgA level （172.08±35.40 ng/g vs 118.27±33.93 ng/g, P〈0.01） and β-galactosidase activity （1.28±0.23 U/g vs 1.82±0.58 U/g, P〈0.05） CONCLUSION： The results have shown that conglycinin is good source for enzyme-mediated production of peptides which stimulate the growth of bifidobacteria. These peptid

关键词： Conglycinin pepsin peptides bifidobacteria

Progress in Modeling of Phase Transformation Kinetics

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Journal of Iron and Steel Research International 2006年第3期13卷 68-73页

作者： ZHAO Hong-zhuang LIU xiang-hua WANG Guo-dong State Key Lab of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China

Several methods representing the evolution of microstructure were introduced, which include the Johnson-Mehl-Avrami-Kolmogorov （JMAK） equation, Internal State Variable （ISV） framework, Koistinen-Marburger （K-M） equation, modified Magee＇s rule and phase field model, etc. By combining calculation of martensite transformation kinetics, considering the selection of parameters with the effect of austenite grain size （AGS）, some suitable ways of obtaining better results have been proposed.

关键词： phase transformation kinetics modeling numerical simulation

Chiral Phosphoric Acid Catalyzed Asymmetric Synthesis of Axially Chiral Compounds

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Chinese Journal of Chemistry 2021年第7期39卷 1787-1796页

作者： Bing-Chao Da Shao-hua xiang Shaoyu Li Bin Tan Department of Chemistry and Shenzhen Grubbs Institute Southern University of Science and TechnologyShenzhenGuangdong 518055China Academy for Advanced Interdisciplinary Studies Southern University of Science and TechnologyShenzhenGuangdong 518055China

The well-defined conformational properties of axially chiral compounds bring extraordinary values to an assortment of bioactive molecules,advanced materials,organocatalysts as well as chiral ligands in asymmetric *** demonstrated usefulness and untapped potential of axially chiral structural motifs stimulate increasing efforts to develop novel and efficient approaches for their *** this regard,the chiral phosphoric acids broadly used in asymmetric Brønsted acid catalysis have shown high relevance for atroposelective synthesis as *** strong interest in reaction chemistry of atropisomers has established a rewarding research programme in our *** course of studies will be recounted in this account,with discussion focused on the use of chiral phosphoric acids to catalyze construction of several key axially chiral structures such as BINAM,BINOL,NOBIN,arylquinones,SPINOL,arylpyrrole analogues and axially chiral alkenes.

关键词： Axial chirality Organocatalysis Chiral phosphoric acid Biaryls Asymmetric synthesis

Novel therapeutic approaches for hepatocellulcar carcinoma: Fact and fiction

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World Journal of Gastroenterology 2008年第11期14卷 1641-1642页

作者： Yuan-Yuan Zhang Harry hua-xiang Xia Department of Microbiology and Microbial Engineering School of Life Sciences Fudan University Shanghai 200433 China Novartis Pharmaceuticals Corporation East Hanover New Jersey United States

Hepatocellular carcinoma(HCC)is the most common primary liver cancer and accounts for 80%-90% of this class of *** far,understanding of its pathogenesis and effective therapeutic methods are rather *** this issue,11 invited review articles are published to address current advance of underlying molecular mechanisms for the deve-lopment of HCC, and novel therapeutic approaches for *** series of review articles provide an in-depth unders-tanding of HCC that has led to or may lead to the development of novel therapies for HCC.

关键词： Hepatocellular carcinoma Pathogenesis Treatment

Factors Affecting Temperature Distribution Along Thickness of Plate During Cooling Process and Their Control Strategies

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Journal of Iron and Steel Research International 2010年第5期17卷 17-22页

作者： CAI Xiao-hui ZHANG Dian-hua LIU xiang-hua WANG Guo-dong State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110819 Liaoning China

On the basis of the finite difference method, the factors affecting the temperature distribution along the thickness of plate during cooling process were analyzed, which include transformation heat, coefficient of heat conduction, specific heat, carbon content, cooling time, plate thickness, and unit of water flow volume. To ensure the homogenous temperature distribution along the thickness of plate, some cooling strategies, such as interval cooling, stepped cooling, and unsymmetrical cooling of upper and lower surfaces, were applied online. The online results showed that the cooling strategies can improve the temperature homogeneity greatly and the finite difference method can correctly simulate the cooling process.

关键词： temperature distribution thermophysical parameter cooling strategy

Splitting Rolling Simulated by Reproducing Kernel Particle Method

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Journal of Iron and Steel Research International 2007年第3期14卷 42-46页

作者： CUI Qing-ling LIU xiang-hua WANG Guo-dong State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China

During splitting rolling simulation, re-meshing is necessary to prevent the effect of severe mesh distortion when the conventional finite element method is used. However, extreme deformation cannot be solved by the finite element method in splitting rolling. The reproducing kernel particle method can solve this problem because the continuum body is discretized by a set of nodes, and a finite element mesh is unnecessary, and there is no explicit limitation of mesh when the metal is split. To ensure stability in the large deformation elastoplastic analysis, the Lagrange material shape function was introduced. The transformation method was utilized to impose the essential boundary conditions. The splitting rolling method was simulated and the simulation results were in accordance with the experimental ones in the literature.

关键词： elasto-plasticity large deformation reproducing kernel particle method splitting rolling