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Modeling effect of cooling conditions on solidification process during thermal cycle of rollers in twin-roll strip casting

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Journal of Iron and Steel Research International 2023年第1期30卷 64-73页

作者： Chun-feng Bai bo Wang Jie ma Jie-yu Zhang Wan-ping Pan State Key Laboratory of Advanced Special Steel Shanghai UniversityShanghai 200072China School of materials Science and Engineering Shanghai UniversityShanghai 200072China Anhui Jianzhu University Hefei 230601AnhuiChina

In the twin-roll strip casting process,molten steel solidifies by losing heat through its interface with the casting *** heat extraction along this interface has an effect on the quality of the strips and should be affected by coating,rolls’material,and cooling water flow *** is necessary to understand the effect of these casting parameters on the solidification structure of twin-roll strip casting.A three-dimensional computational domain is set up to simulate the solidification process of molten steel and heat exchange between steel strip/air,coating,rolls,and cooling water in the channel of roll *** effect of the cooling water intensity and flow intensity of molten steel in the pool on the solidification structures is studied during the thermal cycle of rolls in the twin-roll strip *** predicted results are helpful to optimize casting parameters and improve the strip quality in the twin-roll strip casting process.

关键词： Twin-roll strip casting Solidification structure Numerical simulation Thermal cycle Cellular automata finite element model

Lump Solutions for Two Mixed Calogero-bogoyavlenskii-Schiff and bogoyavlensky-Konopelchenko Equations

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Communications in Theoretical Physics 2019年第6期71卷 658-662页

作者： bo Ren Wen-Xiu ma Jun yu Institute of Nonlinear Science Shaoxing UniversityShaoxing312000China Department of mathematics and Statistics University of South FloridaTampaFL33620-5700USA Department of mathematics Zhejiang Normal UniversityJinhua321004China College of mathematics and Physics Shanghai University of Electric PowerShanghai200090China College of mathematics and Systems Science Shandong University of Science and TechnologyQingdao266590China International Institute for Symmetry Analysis and mathematical Modelling Department of Mathematical SciencesNorth-West UniversityMafikeng CampusPrivate Bag X2046Mmabatho2735South Africa

Based on the Hirota bilinear operators and their generalized bilinear derivatives, we formulate two new(2+1)-dimensional nonlinear partial differential equations, which possess lumps. One of the new nonlinear differential equations includes the generalized Calogero-bogoyavlenskii-Schiff equation and the generalized bogoyavlenskyKonopelchenko equation as particular examples, and the other has the same bilinear form with different Dp-operators.A class explicit lump solutions of the new nonlinear differential equation is constructed by using the Hirota bilinear approaches. A specific case of the presented lump solution is plotted to shed light on the charateristics of the lump.

关键词： generalized Calogero-bogoyavlenskii-Schiff equation generalized bogoyavlensky-Konopelchenko equation Hirota bilinear Lump solution

Catalysis by subsurface metal atoms in Al(001) through electron transfer

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National Science Review 2024年第4期11卷 12-13页

作者： bo Sun Ding ma Beijing National Laboratory for Molecular Science New Cornerstone Science Laboratory College of Chemistry and Molecular Engineering Peking University

Heterogeneous catalysis plays a crucial role in the chemical industry, which has evolved from the investigation of chemisorption to an electronic structure[1]. Diverse strategies, such as alloying,doping, and confining, have been applied to enhance the catalytic properties of active sites through electronic modulation. The electron transfer between active sites and substrates profoundly influences catalytic activity [2].

关键词： catalysis through metal atoms electron subsurface transfer

Decreased levels of phosphorylated synuclein in plasma are correlated with poststroke cognitive impairment

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Neural Regeneration Research 2025年第9期20卷 2598-2610页

作者： Yi Wang yuning Li Yakun Gu Wei ma yuying Guan Mengyuan Guo Qianqian Shao Xunming Ji Jia Liu Department of Clinical Laboratory Beijing Bo’ai HospitalChina Rehabilitation Research CenterCapital Medical UniversityBeijingChina Beijing Institute of Brain Disorders Laboratory of Brain DisordersMinistry of Science and TechnologyCollaborative Innovation Center for Brain DisordersBeijing Advanced Innovation Center for Big Data-based Precision MedicineCapital Medical UniversityBeijingChina Department of Neurosurgery Xuanwu HospitalCapital Medical UniversityBeijingChina

Poststro ke cognitive impairment is a major secondary effect of ischemic stroke in many patients;however,few options are available for the early diagnosis and treatment of this *** aims of this study were to(1)determine the specific relationship between hypoxic andα-synuclein during the occur of poststroke cognitive impairment and(2)assess whether the serum phosphorylatedα-synuclein level can be used as a biomarker for poststro ke cognitive *** found that the phosphorylatedα-synuclein level was significantly increased and showed pathological aggregation around the cerebral infa rct area in a mouse model of ischemic *** addition,neuronalα-synuclein phosphorylation and aggregation were observed in the brain tissue of mice subjected to chronic hypoxia,suggesting that hypoxia is the underlying cause ofα-synuclein-mediated pathology in the brains of mice with ischemic *** phosphorylatedα-synuclein levels in patients with ischemic stroke were significantly lower than those in healt hy subjects,and were positively correlated with cognition levels in patients with ischemic ***,a decrease in serum high-density lipoprotein levels in stroke patie nts was significantly correlated with a decrease in phosphorylatedα-synuclein *** ischemic stroke mice did not show significant cognitive impairment or disrupted lipid metabolism 14 days after injury,some of them exhibited decreased cognitive function and reduced phosphorylatedα-synuclein *** together,our results suggest that serum phosphorylatedα-synuclein is a potential biomarker for poststroke cognitive impairment.

关键词： biomarker high-density lipoprotein ischemic stroke phosphorylatedα-synuclein poststroke cognitive impairment

Influence of different high pressure die casting processes on 3D porosity distribution of Mg-3.0Nd-0.3Zn-0.6Zr alloy

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China Foundry 2021年第6期18卷 521-528页

作者： Yi-hu ma Wen-bo yu yu-qi Zhou Shou-mei Xiong Center of materials Science and Engineering School of Mechanical and Electronic Control EngineeringBeijing Jiaotong UniversityBeijing 100044China School of materials Science and Engineering Tsinghua UniversityBeijing 100084China

3D reconstruction was adopted to characterize the microstructural morphologies of Mg-3.0Nd-0.3Zn-0.6Zr alloy castings produced by high pressure die casting(HPDC)processes with different parameters,including low slow-shot speed,solidification pressurization and fast slow-shot *** low slow-shot speeds of 0.1 m·s^(-1),0.2 m·s^(-1) and 0.3 m·s^(-1),the porosity is concentrated in the center of the castings with one spiral staggered shape along the liquid flow *** porosity volume simultaneously decreases with the reduction of quantity and size of externally solidified crystals(ESCs),while the shrinkage pores become more and more dispersed with the increasing low slow-shot *** not only reduces the porosity volume due to the improvement of feeding ability,but also transformes the center gathered porosity into one layer-by-layer distribution *** with the increasing fast slow-shot speed,the central porosity dramatically decreases and transforms into a large-scale spiral staggered shape along the liquid flow ***,the porosity is much more dispersed when the speed is increased from 2 m·s^(-1) to 3 m·s^(-1).

关键词： HPDC parameters porosity volume 3D morphology

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巴西龟代谢性骨病CT诊断病例报告

动物医学进展 2025年第1期46卷 141-144页

作者：孙嘉徐甘靖宇江蓝刘波俞峰中国农业大学北京100193

代谢性骨病(MBD)是一种因钙缺乏或维生素D 3摄入不足引起的骨骼代谢障碍疾病,其临床表现为骨折、脊椎异常、难产、脱垂等症状。计算机断层扫描(CT)在兽医临床中应用的逐渐增加为龟、鳖类MBD提供了新的诊断方式。该病例中红耳巴西龟血检... 详细信息

代谢性骨病(MBD)是一种因钙缺乏或维生素D 3摄入不足引起的骨骼代谢障碍疾病,其临床表现为骨折、脊椎异常、难产、脱垂等症状。计算机断层扫描(CT)在兽医临床中应用的逐渐增加为龟、鳖类MBD提供了新的诊断方式。该病例中红耳巴西龟血检结果提示其肾脏、肝脏功能损害,钙磷代谢异常。CT扫查提示患龟全身组织大面积矿化、背甲凹陷,定量测量患龟背椎骨、神经骨和胸膜骨3处的骨骼密度远低于正常龟,诊断患龟有严重的MBD。治疗方案为对症治疗、改善饲养管理条件,同时对该龟补充维生素D 3。该病例报告系统陈述了龟鳖MBD的诊疗流程,同时表明了CT扫查可为龟鳖MBD精确诊断、治疗和预后提供新的参考。

关键词：龟代谢性骨病计算机断层扫描骨密度

Exploring the relevance between load-bearing capacity and surface friction behavior based on a layered hydrogel cartilage prototype

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Friction 2024年第8期12卷 1757-1770页

作者： yunlei ZHANG Weiyi ZHAO Xiaoduo ZHAO Jinshuai ZHANG bo yu Shuanhong ma Feng ZHOU State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China College of materials Science and Opto-Electronic Technology University of Chinese Academy of SciencesBeijing 100049China Shandong Laboratory of Yantai Advanced materials and Green manufacture Yantai Zhongke Research Institute of Advanced Materials and Green Chemical EngineeringYantai 264006China

Cartilage is well lubricated over a lifetime and this phenomenon is attributed to both of the surface hydration lubrication and the matrix load-bearing *** hydrogels with a layered structure are designed to mimic cartilage as potential *** many studies have concentrated on improving surface hydration to reduce friction,few have experimentally detected the relationship between load-bearing capacity of hydrogels and their interface friction *** this work,a bilayer hydrogel,serving as a cartilage prototype consisted of a top thick hydrated polymer brush layer and a bottom hydrogel matrix with tunable modulus was designed to investigate this *** coefficient of friction(COF,μ)is defined as the sum of interfacial component(μInt)and deformation/hysteresis component(μHyst).The presence of the top hydration layer effectively dissipates contact stress and reduces the interface interaction(μInt),leading to a stable and low *** contribution of mechanical deformation(μHyst)during the sliding shearing process to COF can be significantly reduced by increasing the local mechanical modulus,thereby enhancing the load-bearing *** results show that the strategy of coupling surface hydration layer with a high load-bearing matrix can indeed enhance the lubrication performance of hydrogel cartilage prototypes,and implies a promising routine for designing robust soft matter lubrication system and friction-control devices.

关键词： soft contact hydration,deformation load-bearing friction control

Effect of Zn addition on microstructure and mechanical properties of Mg-3Y-2Nd-0.5Zr alloy

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China Foundry 2023年第4期20卷 299-306页

作者： Fei-yu He Wen-xin Hu Li-juan Liu Shao-bo ma Wei He State Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization Baotou 014030Inner MongoliaChina Baotou Research Institute of Rare Earths Baotou 014030Inner MongoliaChina Technical Center of Steel Union Co. Ltd.of Baotou Steel(Group)Corp.Baotou 014010Inner MongoliaChina

The effect of 0.5wt.%Zn addition on the microstructure and mechanical properties of Mg-3Y-2Nd-0.5Zr(WE32)alloy was *** results indicate that WE32-0.5Zn alloy takes 48 h to reach peak hardness after solid solution treatment at 525℃and aging at 200℃,10 h earlier than WE32 alloy,which implies an accelerated aging precipitation kinetics owing to the addition of 0.5wt.%Zn.A large quantity of finerod and rectangular block-like Zn-Zr precipitates in theα-Mg matrix are formed in the WE32-0.5Zn alloy,and numerous needle-likeβ1phases are distributed at both ends of the Zn-Zr precipitates at peak-aged *** peak-aged condition,the ultimate tensile strength considerably increases from 263.2 MPa(WE32)to 309.6 MPa(WE32-0.5Zn),and the elongation dramatically increases from 4.3%(WE32)to 8.9%(WE32-0.5Zn).Theβ’andβ1phases are the main precipitates of the WE32-0.5Zn alloy peak-aged at 200℃.Theβ’andβ1phases easily nucleate at the Zn-Zr precipitates,and theβ1phases are particularly likely to nucleate and grow at the interface between the two ends of the Zn-Zr precipitates,which accelerates aging precipitation kinetics and leads to a shorter time to achieve peak aging.

关键词： Mg-3Y-2Nd-0.5Zr Zn-Zr precipitates microstructure mechanical properties

Exopolysaccharides from lactic acid bacteria,as an alternative to antibiotics,on regulation of intestinal health and the immune system

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Animal Nutrition 2023年第2期13卷 78-89页

作者： Shuo Yang Xiaoqing Xu Qing Peng Lan ma yu Qiao bo Shi Feed Research Institute Chinese Academy of Agricultural SciencesBeijing100081China

Over-use or misuse of antibiotics in livestock and poultry production contributes to the rising threat of antibiotic resistance in animals and has negative ecological *** from lactic acid bacteria(LAB-EPS)are a class of biological macromolecules which are secreted by lactic acid bacteria to the outside of the cell wall during their growth and *** studies demonstrated that LAB-EPS have anti-inflammatory and antimicrobial activities and are able to regulate intestinal health and the immune system in *** are biodegradable,nontoxic and bio-compatible,which are considered as ideal alternatives to *** review aims to discuss and summarize recent research findings of LAB-EPS on regulation of intestinal health and the immune system in animals,and thus provide scientific justification for commercial applications of LAB-EPS in livestock.

关键词： Lactic acid bacteria Exopolysaccharides Intestinal health Immune function