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The effect of welding heat input on the weldpool behavior in MIG welding

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Science China(Technological Sciences) 2002年第3期45卷 291-299页

作者：孙俊生武传松 1. key laboratory of Liquid Structure and heredity of Material of Ministry of Education Shandong University 250061 Jinan China

For metal-inert gas welding (MIG), the welding heat input includes the arc heat flux on the surface of workpiece and the volumetric distribution of droplets’ heat content within the weldpool. Based on the general principle of arc physics and the physical nature of the action of droplets and weldpool, a distribution mode of current density on the deformed weldpool surface and the heat content of filler metal droplets inside the weldpool is established in this paper. Numerical analysis is used to study the distribution of current density in MIG welding, the distribution mode of the heat content of filler metal droplets, weldpool geometry, the fluid flow and temperature profiles. Experiments are performed to prove the reliability of the calculated mode.

关键词： arc heat flux, droplets' heat content, distribution mode, weldpool behavior

Targeting mitochondria with antioxidant nutrients for the prevention and treatment of postweaning diarrhea in piglets

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Animal Nutrition 2023年第4期15卷 275-287页

作者： Lei Qiao Xina Dou Xiaofan Song Jiajing Chang Hongbo Yi Chunlan Xu School of Life Sciences Northwestern Polytechnical UniversityXi'anShaanxi710072China State key laboratory of Livestock and poultry breeding Ministry of Agriculture Key Laboratory of Animal Nutrition and Feed Science in South ChinaGuangdong Provincial Key Laboratory of Animal Breeding and NutritionInstitute of Animal Science of Guangdong Academy of Agricultural SciencesGuangzhouGuangdong510640China

Post-weaning diarrhea(PWD)in piglets poses a significant challenge and presents a grave threat to the global swine industry,resulting in considerable financial losses and compromising the welfare of *** is commonly associated with gut homeostatic imbalance,including oxidative stress,excessive inflammation,and microbiota *** use has historically been a common initiative to combat PWD,but concerns about the development of antibiotic resistance have led to increased interest in alternative *** are key players in maintaining cellular homeostasis,and their dysfunction is intricately linked to the onset and progression of *** evidence suggests that targeting mitochondrial function using antioxidant nutrients,such as vitamins,minerals and polyphenolic compounds,may represent a promising approach for preventing and treating ***,nutrients based on antioxidant strategies have been shown to improve mitochondrial function,restore intestinal redox balance,and reduce oxidative damage,which is a key driver of *** present review begins with an overview of the potential interplay between mitochondria and gut homeostasis in the pathogenesis of PWD in ***,alternative strategies to prevent and treat PWD using antioxidant nutrients to target mitochondria are described and ***,we delve into potential limitations and suggest future research directions in this field for further ***,targeting mitochondria using antioxidant nutrients may be a promising approach to combat PWD and provides a potential nutrition intervention strategy for regulating gut homeostasis of weaned piglets.

关键词： Post-weaning diarrhea Piglet Antioxidant Nutrient Mitochondria

Replacing dietary sodium selenite with biogenic selenium nanoparticles improves the growth performance and gut health of early-weaned piglets

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Animal Nutrition 2023年第4期15卷 99-113页

作者： Lei Qiao Xina Dou Xiaofan Song Jiajing Chang Xiaonan Zeng Lixu Zhu Hongbo Yi Chunlan Xu School of Life Sciences Northwestern Polytechnical UniversityXi'anShaanxi 710072China State key laboratory of Livestock and poultry breeding Ministry of Agriculture Key Laboratory of Animal Nutrition and Feed Science in South ChinaGuangdong Provincial Key Laboratory of Animal Breeding and NutritionInstitute of Animal Science of Guangdong Academy of Agricultural SciencesGuangzhouGuangdong 510640China

Selenium nanoparticles(SeNPs)are proposed as a safer and more effective selenium delivery system than sodium selenite(Na_(2)SeO_(3)).Here,we investigated the effects of replacing dietary Na_(2)SeO_(3)with SeNPs synthesized by Lactobacillus casei ATCC 393 on the growth performance and gut health of earlyweaned ***-two piglets(Duroc×Landrace×Large Yorkshire)weaned at 21 d of age were divided into the control group(basal diet containing 0.3 mg Se/kg from Na_(2)SeO_(3))and SeNPs group(basal diet containing 0.3 mg Se/kg from SeNPs)during a 14-d feeding *** results revealed that SeNPs supplementation increased the average daily gain(P=0.022)and average daily feed intake(P=0.033),reduced(P=0.056)the diarrhea incidence,and improved(P=0.013)the feed conversion ratio compared with Na_(2)SeO_(3).Additionally,SeNPs increased jejunal microvilli height(P=0.006)and alleviated the intestinal barrier dysfunction by upregulating(P<0.05)the expression levels of mucin 2 and tight junction proteins,increasing(P<0.05)Se availability,and maintaining mitochondrial structure and function,thereby improving antioxidant capacity and ***,metabolomics showed that SeNPs can regulate lipid metabolism and participate in the synthesis,secretion and action of parathyroid hormone,proximal tubule bicarbonate reclamation and tricarboxylic acid ***,SeNPs increased(P<0.05)the abundance of Holdemanella and the levels of acetate and *** analysis suggested that Holdemanella was closely associated with the regulatory effects of SeNPs on early-weaned piglets through participating in lipid ***,replacing dietary Na_(2)SeO_(3)with biogenic SeNPs could be a potential nutritional intervention strategy to prevent earlyweaning syndrome in piglets.

关键词： Selenium nanoparticle Early-weaned piglet Gut homeostasis Gut microbiota

Al-Si/Al_2O_3 in situ composite prepared by displacement reaction of CuO/Al system

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China Foundry 2010年第1期7卷 19-23页

作者： Zhang Jing Yu Huashun Chen Hongmei Min Guanghui key laboratory of Liquid Structure and heredity of Materials Ministry of Education Shandong University Jinan Shandong China

Al2O3 particle-reinforced ZL109 composite was prepared by in situ reaction between CuO and Al2O3 . The microstructure was observed by means of OM, SEM and TEM. The Al2O3 particles in sub-micron sizes distribute uniformly in the matrix, and the Cu displaced from the in situ reaction forms net-like alloy phases with other alloy elements. The hardness and the tensile strength of the composites at room temperature have a slight increase as compared to that of the matrix. However, the tensile strength at 350℃ has reached 90.23 MPa, or 16.92 MPa higher than that of the matrix. The mechanism of the reaction in the CuO/AI system was studied by using of differential scanning calorimetry（DSC） and thermodynamic calculation. The reaction between CuO and Al involves two steps. First, CuO reacts with Al to form Cu20 and Al2O3 at the melting temperature of the matrix alloy, and second, Cu20 reacts with Al to form Cu and Al2O3 at a higher temperature. At ZL109 casting temperature of 750- 780 ℃, the second step can also take place because of the effect of exothermic reaction of the first step.

关键词： aluminium matrix composites in situ reaction Al2O3 particles ZL109 CuO

Effect of Cerium on the Viscosity of Liquid Fe-C Alloy of Eutectic Content

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Journal of Rare Earths 2002年第6期20卷 630-634页

作者：滕新营叶以富key laboratory of Liquid Structure and heredity of Materials Ministry of Education South Campus of Shandong University 刘含莲王焕荣石志强耿浩然 key laboratory of Liquid Structure and heredity of Materials Ministry of Education South Campus of Shandong University College of Mechanical Engineering Shandong University

The viscosities of liquid Fe-4.30C and Fe-4.30C-Ce alloys were measured by oscillating crucible viscometer. The results show that viscosity of Fe-4.30C alloy changes from 5.50 to 8.30 MPa·s when the liquid is cooled from 1425 ℃ to the melting point. The abnormity of viscosity of Fe-4.30C alloy near the melting point is reasonable due to the formation of graphite. The addition of cerium especially with content higher than 0.21% causes an evidently decrease in viscosity for eutectic alloy resulting from increase of free volume and size decrease of atom cluster in the liquids. It can be concended that the existence of C-Ce compound contributes to the discontinuous of viscosity at 1340～1370 ℃ for the Fe-4.30C-Ce alloy by experinments with differential scanning calorimeter.

关键词： rare earths cerium viscosity liquid eutectic Fe-C alloy

High temperature corrosion of silicon nitride composite ceramics in sulfur-oxygen environments

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中国有色金属学会会刊：英文版 2003年第2期13卷 311-314页

作者：王昕孙康宁李静于薛刚尹衍升杨连喜 key laboratory of Liquid Structure and heredity of Materials Ministry of Education Shandong University key laboratory of Engineering Ceramics Shandong Province Shandong University Jinan 250061 China key laboratory of Engineering Ceramics Shandong Province Shandong University

High temperature corrosion behavior of Si 3N 4 8%Al 2O 3(volume fraction) composite ceramics in sulfur oxygen environments was studied. At 1 150 ℃ and 1 350 ℃,the corrosion processes follow parabolic law with parabolic rate constants ( K p) of 1.45×10 -9 g 2·cm -4 ·s -1 and 7.92×10 -9 g 2·cm -4 ·s -1 , respectively. The corrosion mechanisms are different at different temperatures. At 1 150 ℃, the corrosion of the material is due to the destruction of SiO 2 layer caused by sulfur and the active oxidation corrosion. At 1 350 ℃ , the diffusion of additives and impurity elements to grain boundaries and outward to surface layers lead to the formation, growth and break of bubbles, which accelerates the corrosion rate of the Si 3N 4 ceramics.

关键词：高温氧化高温腐蚀二氧化硫氮化硅陶瓷

Au-Ag Alloy Nanoporous Nanotubes

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Nano Research 2009年第5期2卷 386-393页

作者： Xiaohu Gu Liqiang Xu Fang Tian Yi Ding School of Chemistry and Chemical Engineering Key Laboratory of Liquid Structure and Heredity of MaterialsMinistry of EducationShandong UniversityJinan 250100China

Metallic nanostructures with hollow interiors or tailored porosity represent a special class of attractive materials with intriguing chemicophysical *** paper presents the fabrication of a new type of metallic nanoporous nanotube structure based on a facile and effective combination of nanocrystal growth and surface *** controlling the individual steps involved in this process,such as nanowire growth,surface modification,thermal diffusion,and dealloying,one-dimensional(1-D)metallic nanostructures can be prepared with tailored structural features and pre-designed *** tubular and porous nanostructures show distinct optical properties,such as tunable absorption in the near-infrared region,and enhanced capability for electrochemiluminescence signal amplification,which make them particularly desirable as novel 1-D nano-carriers for biomedical,drug delivery and sensing applications.

关键词： Nanoporous nanotube gold optical properties electrochemiluminescence

Dietary supplementation with 2-hydroxy-4-methyl(thio)butanoic acid and DL-methionine improves productive performance,egg quality and redox status of commercial laying ducks

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Animal Nutrition 2023年第3期14卷 101-110页

作者： Yanan Zhang Zhiwei Zhuang Tahir Mahmood Yves Mercier Yongyan Jin Xuebing Huang Kaichao Li Shuang Wang Weiguang Xia Shenglin Wang Miao Yu Wei Chen Chuntian Zheng Institute of Animal Science Guangdong Academy of Agricultural SciencesKey Laboratory of Animal Nutrition and Feed Science(South China)of Ministry of AgricultureState Key Laboratory of Livestock and Poultry BreedingGuangdong Public Laboratory of Animal Breeding and NutritionGuangdong Key Laboratory of Animal Breeding and Nutrition510640GuangzhouChina Institute of Life Science and Engineering Foshan University528200FoshanChina Adisseo France S.A.S.Centre of Excellence and Research in Nutrition CommentryFrance

This experiment aimed to study the effects of supplemental methionine sources,2-hydroxy-4 methyl(thio)butanoic acid(HMTBa)and DL-Methionine(DL-Met),on productive performance,egg quality,and redox status of laying ducks.A total of 792 healthy 25-wk-old Longyan laying ducks with similar body weights were randomly allotted to 11 treatment *** treatment group had 6 replicates of 12 *** trial lasted for 16 *** were fed a basal deficient diet(Met:0.24%;Met+Cys:0.51%)or supplemented with DL-Met or HMTBa at 0.05%,0.12%,0.19%,0.26%,and 0.33%of diet,*** with the basal diet,supplementation with either DL-Met or HMTBa increased the average egg weight,egg mass,and decreased feed to egg ratio during the whole trial period(P<0.05).Albumen weight and its ratio to total egg weight were increased,but yolk and shell ratio,albumen height,Haugh unit and shell breaking strength were decreased(P<0.05).Dietary DL-Met or HMTBa supplementation increased taurine,methionine,leucine,tryptophan and arginine content,and decreased serine and lysine content in plasma(P<0.05).The redox status of laying ducks was improved by enhancing the glutathione peroxidase and catalase activities,glutathione content and its ratio relative to glutathione(oxidized)content and decreasing malondialdehyde content and increasing mRNA expression of superoxide dismutase-1,glutathione peroxidase-1,hemeoxygenase-1 and nuclear factor-like 2 in liver and ileum with the supplementation of DL-Met or HMTBa(P<0.05).Liver health status measured by average area proportion lipid droplet was improved with supplementation of DL-Met or HMTBa(P<0.05).Villus height and villus height to crypt depth ratio in the ileum and the ileal gene expression of tight junction protein and occludin were increased with DL-Met or HMTBa supplementation(P<0.05).Taken together,these results suggested that the efficacy of dietary supplementation of HMTBa was similar to DL-Met,and it ranged from 98%to 100%for productive

关键词： DL-Methionine 2-Hydroxy-4 methyl(thio)butanoic acid Productive performance Efficacy Laying duck

Scheme for direct measurement of Wigner function in two-mode cavity QED driven by classical fields

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Chinese Physics B 2010年第12期19卷 255-262页

作者：吴怀志杨贞标郑仕标 Department of Physics and State key laboratory breeding Base of Photocatalysis Fuzhou University

We propose a scheme for the direct measurement of Wigner function in two-mode cavity QED. The atoms are sent to resonantly interact with two orthogonally polarized cavity modes in the presence of strong classical field. The probability of measuring the atom in the ground state directly gives the useful information of the cavity field. This method can be used for quantum non-demolition measurement of the photon number.

关键词： two-mode cavity Wigner function quantum non-demolition measurement