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Preparation of Pt/γ-Al2O3-C Heterogeneous Catalyst for Highly selective Hydrogenation of Cinnamaldehyde Towards Cinnamyl Alcohol

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Chemical Research in Chinese Universities 2017年第4期33卷 660-665页

作者： ma Jun sichuan Province Institutions of Higher Education and Key Laboratory of Land Resources Evaluation and Monitoring in southwest Ministry of Education Chengdu 610068 P. R. China

A Pt/γ-Al2O3-C heterogeneous catalyst with improved catalytic performance was successfully prepared. Bayberry talmin（BT）, an abundant natural plant polyphenol, was utilized to modifiy the surface of the Pt/γ-Al2O3 matrix and then stabilize Pt nanoparticles（NPs）. The catalyst was systematically and specifically characterized by a collec- tion of analytic tools including XRD, XPs, FTIR, TEM, and TG. It was found that the Pt NPs were envenly dispered on the γ-Al2O3-C matrix. Meanwhile, when the catalyst was applied for selective hydrogenation of cilmamalde- hyde（Cma） in the presence of KOH promoter in solvent, excellent catalytic performance was obtained. The selecti- vity to cinnamyl alcohol（CMO） reached 97.88% with 88.45% Cma conversion within 30 min in the presence of 0.037 mol/L KOH, without significant loss of catalytic activity even under cyclic measurements for 5 times. The excelleut catalytic performances should be ascribed predominantly to the uniform and stable dispersion ofPt NPs on the γ-Al2O3-C matrix and the excellent heat stability of BT.

关键词： Heterogeneous catalyst Pt/γ-Al2O3-C Barberry tannin selective hydrogenation Ciunamaldehyde

structure evolution of the Fe_(3)C/Fe interface mediated by cementite decomposition in cold-deformed pearlitic steel wires

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Journal of materials science & Technology 2022年第6期101卷 28-36页

作者： Y.T.Zhou X.H.shao s.J.Zheng X.L.ma shenyang National Laboratory for materials science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Tianjin Key Laboratory of materials Laminating Fabrication and Interface Control Technology School of Materials Science and EngineeringHebei University of TechnologyTianjin 300130China

Cold-drawn pearlitic steel wire is irreplaceably used in industry owing to its outstanding mechanical property which is dominated by the cementite/ferrite(Fe_(3)C/Fe) interfaces in the material. However, the fine structures of the Fe3C/Fe interfaces in the deformed wires are less known to date. In this work, transmission electron microscopic investigation was performed on the atomic structures of the interfaces with the Isaichev orientation relationship(OR) in the wires with progressive deformation strains. In addition to the effect of the dislocation/interface interactions, this work revealed that the deformation-induced partial decomposition of cementite pla.s.a. important role in the interface reconstruction during deformation. The interfacial carbon vacancies generated by cementite decomposition and particularly, the amorphization of cementite layers in the sample with ε > 1 could effectively annihilated the interfacial dislocations and consequently relaxed the interfacial stress. The correlations between the interface structure changes and the mechanical properties of the wires were discussed.

关键词： Pearlitic steel Cementite decomposition Interface structure Deformation Transmission electron microscopy

Fabrication of high strength carbon nanotube/7055Al composite by powder metallurgy combined with subsequent hot extrusion

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science China(Technological sciences) 2021年第5期64卷 1081-1091页

作者： ma Kai LIU ZhenYu ZHANG XingXing XIAO BoLv ma ZongYi shi-changxu Innovation Center for Advanced materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China school of materials science and Engineering University of Science and Technology of ChinaShenyang 110016China

Bimodal carbon nanotube reinforced 7055Al(CNT/7055Al) composites containing coarse grain bands and ultra-fine grain zones were fabricated by high energy ball milling, vacuum hot pressing followed by hot extrusion. The effect of extrusion temperature varied from 320℃ to 420℃ on the microstructure evolution and tensile properties were investigated. Microstructure observation indicates that the elongated coarse grain bands aligned along the extrusion direction after extrusion. The width of the coarse grain bands increased, and the length of the coarse grain bands increased firstly and then decreased with the increase of extrusion temperature. The grain size of the ultra-fine grain zones changed little after hot extrusion, but the ultra-fine grains coarsened after subsequent heat treatment, especially for the composite extruded at low temperature of 320℃. By observing the CNT distribution, it was found that the higher temperature extrusion was beneficial to the CNT orientation along the extrusion ***, a precipitated free zone formed at the boundary between the coarse grain band and the ultra-fine grain zone as the composite extruded at high temperature of 420℃. As the result of the comprehensive influence of the above microstructure, the tensile strength of the composite extruded at moderate temperature of 370℃ reached the highest of 826 MPa.

关键词： carbon nanotube aluminum matrix composite hot extrusion bimodal mechanical property

Hydration lubrication modulated by water structure at TiO2–aqueous interfaces

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Friction 2024年第4期12卷 591-605页

作者： Pingsu ma Yuan LIU Ke HAN Yu TIAN Liran ma state Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China

The nature of solid-liquid interfaces is of great significance in *** advances have been made in lubrication based on hydration ***,a detailed molecular-level understanding is still ***,we investigated water molecule behaviors at the TiO2-aqueous interfaces by the sum-frequency generation vibrational spectroscopy(sFG-Vs)and atomic force microscope(AFM)to elucidate the fundamental role of solid-liquid interfaces in *** contributions of water structures and hydration effects were revealed,where water structures played the dominant role in lubrication for TiO2 surfaces of varying hydrophilicity,while hydration effects dominated with the increasing of ion *** lubrication is observed on the initial TiO2 surfaces with strongly H-bonded water molecules compared to the hydrophilic TiO2 surfaces with more disordered *** stable ordered water arrangement with strong hydrogen bonds and the shear plane occurring between the ordered water layer and subsequent water layer may play a significant role in achieving lower *** adsorbed hydrated molecules with the increasing ionic concentration perturb ordered water but lead to the enhancement of hydration effects,which is the main reason for the improved lubrication for both *** work provides more insights into the detailed molecular-level understanding of the mechanism of hydration lubrication.

关键词： hydration lubrication interfacial water structures hydration effects titanium dioxide(TiO2)

Microfluidics in cardiovascular disease research: state of the art and future outlook

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Microsystems & Nanoengineering 2021年第2期7卷 1-19页

作者： Qingming ma Haixia ma Fenglan Xu Xinyu Wang Wentao sun school of Pharmacy Qingdao UniversityQingdao266071China Center for Prenatal Diagnosis Zibo Maternal and Child Health Care HospitalZibo255000China Department of Clinical Pharmacy The Affiliated Hospital of Jiangsu UniversityJiangsu UniversityZhenjiang212001China Institute of Thermal science and Technology Shandong UniversityJinan250061China Center for Basic Medical Research TEDA International Cardiovascular HospitalChinese Academy of Medical Sciences&School of MedicineNankai UniversityTianjin300457China

Due to extremely severe morbidity and mortality worldwide,it is worth achieving a more in-depth and comprehensive understanding of cardiovascular *** effort has been made to replicate the cardiovascular system and investigate the pathogenesis,diagnosis and treatment of cardiovascular *** can be used as a versatile primary strategy to achieve a holistic picture of cardiovascular ***,a brief review of the application of microfluidics in comprehensive cardiovascular disease research is presented,with specific discussions of the characteristics of microfluidics for investigating cardiovascular diseases integrally,including the study of pathogenetic mechanisms,the development of accurate diagnostic methods and the establishment of therapeutic *** of critical pathogenetic mechanisms for typical cardiovascular diseases by microfluidic-based organ-on-a-chip are categorized and reviewed,followed by a detailed summary of microfluidic-based accurate diagnostic ***-assisted cardiovascular drug evaluation and screening as well as the fabrication of novel delivery vehicles are also ***,the challenges with and outlook on further advancing the use of microfluidics technology in cardiovascular disease research are highlighted and discussed.

关键词： fluid versatile discussions

self-nucleation Effect of Crystallization with Various Nucleating Agents

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Chinese Journal of Polymer science 2023年第12期41卷 1912-1920,I0009页

作者： Dai Zhang Rui-Jun Zhao Gui-Qiu ma Zhe ma Tianjin Key Laboratory of Composite and Functional materials and School of Materials Science and EngineeringTianjin UniversityTianjin 300072China

In this work,the self-nucleation effect on crystallization was studied for polypropylene with various nucleating *** talc was employed to accelerate crystallization of monoclinic α-crystallites,while N,N′-dicyclohexyl-2,6-naphthalenedicarboxamide TMB-5 was used to accelerate the crystallization kinetics and also induce formation of trigonal β-*** induce self-nucleation effect,the occurrence criterion was assessed by the transition temperatures from various domains and the available temperature *** importantly,the resulting influences of self-nucleation effect were quantified by the change of crystallization kinetics and the potential polymorphism *** was found that the α-nucleating agents of talc broadened the temperature window for inducing Domain Ⅱ by elevating the transition temperature from Domain Ⅰ to Domain Ⅱ.Although β-nucleating agent(β-NA)of N,N′-dicyclohexyl-2,6-naphthalenedicarboxamide TMB-5 elevated cooling crystallization temperature obviously,the temperature window for Domain Ⅱ was *** should be emphasized that in presence of β-NA TMB-5,the self-nucleation effect enhances the crystallization of α-crystallite,which show the competition with β-NA *** last,the ternary PP/talc/TMB-5 blend was prepared with the same amounts of α-NA talc and β-NA TMB-5 and it exhibits a similar self-nucleation effect of crystallization,indicating the dominant role of β-NA TMB-5.

关键词： Crystallization Kinetic Polymorphism

An overview of functional biolubricants

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Friction 2023年第1期11卷 23-47页

作者： Lumin YANG Xiaoduo ZHAO Zhengfeng ma shuanhong ma Feng ZHOU state Key Laboratory of solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of materials science and Optoelectronics Enginering University of Chinese Academy of SciencesBeijing 100049China Yantai Zhongke Research Institute of Advanced materia.s.a.d Green Chemical Engineering Yantai 264006China shandong Laboratory of Yantai Advanced materia.s.a.d Green manufacture Yantai 264006China

At present,more and more diseases are associated with the lubrication dysfunction,which requires a systematic study of the complex lubrication behavior of tissues and organs in human *** biomacromolecular lubricants are essential for maintaining ultra-low coefficients of friction between sliding biological ***,when the surface lubrication performance of tissues or organs destroys heavily,it will bring friction/shear damage for sliding contact ***,the application of exogenous biological lubricating materials to improve the lubrication situation of damaged tissue or organ interfaces has attracted extensive attention of *** this review,based on a simple summary of lubrication mechanism at sliding biological interface,we systematically introduce the research progress of several kinds of representatively biolubrication materials,including eye drops,tissue anti-adhesion agents,joint lubricants,and medical device ***,the lubrication mechanism and individual advantage and shortcoming for each of these synthetic exogenous lubricated materia.s.a.e ***,the important lubrication application functionality of these biolubricant materials in typically medical surgery scenes,such as dry eye syndrome,tissue adhesion,arthritis,and interventional medical devices,is ***,we look forward to the future development direction of artificial biolubricant materials.

关键词： biolubricants eye drops tissue anti-adhesion arthritis treatment medical devices

study of a background reconstruction method for the measurement of D-meson azimuthal angular correlations

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Nuclear science and Techniques 2021年第6期32卷 63-69页

作者： Long ma Xin Dong Huan-Zhong Huang Yu-Gang ma Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Institute of Modern PhysicsFudan University200433 ShanghaiChina Nuclear science Division Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA University of California Los AngelesCalifornia 90095USA

We studied experimental background reconstruction methods for the measurement of the D-D correlation using PYTHIA *** like-sign(Ls)and side-band(sB)background methods,which are widely used in the experimental measurements of single D-meson production yields,were deployed for correlation *** was found that the Ls method,which describes the combinatorial background of single D^(0) meson yields,fails to reproduce the correlated background in the D^(0)-D^(0) correlation measurement,while the sB background method yields a good description of the background for both single D^(0) yields and the correlated background of the D^(0)-D^(0) correlation *** further examined the validity of the correlation methods under different signal-to-background ratios,providing direct references for experimental measurements.

关键词： Heavy flavor Azimuthal correlation PYTHIA

Microstructural evolution in friction self-piercing riveted aluminum alloy AA7075-T6 joints

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Journal of materials science & Technology 2021年第23期82卷 80-95页

作者： Yunwu ma sizhe Niu Huihong Liu Yongbing Li Ninshu ma shanghai Key Laboratory of Digital manufacture for Thin-Walled structures School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai200240PR China state Key Laboratory of Mechanical system and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai200240PR China Joining and Welding Research Institute Osaka UniversityOsaka567-0047Japan

Friction self-piercing riveting(F-sPR)is an emerging technique for low ductility materials joining,which creates a mechanical and solid-state hybrid joint with a semi-hollow *** severe plastic deformation of work materia.s.a.d localized elevated temperatures during the F-sPR process yield complex and heterogeneous *** cut-off action of the work materials by the rivet further complicates the material flow during joint *** study employed the F-sPR process to join AA7075-T6 aluminum alloy sheets and systematically investigated the microstructural evolutions using electron backscatter diffraction(EBsD)*** results suggested that as the base material approached the rivet,grains were deformed and recrystallized,forming two distinct fine grain zones(FGZs)surrounding the rivet and in the rivet cavity,re s ***-state bonding of aluminum sheets occurred in the *** formation of FGZ outside the rivet is due to dynamic recrystallization(DRX)triggered by the sliding-to-sticking transition at the rivet/sheet *** FGZ in the rivet cavity was caused by the rotation of the trapped aluminum,which created a sticking affected zone at the trapped aluminum/lower sheet interface and led to *** rate gradient in the trapped aluminum drove the further expansion of the sticking affected zone and resulted in grain refinement in a larger span.

关键词： Friction self-piercing riveting semi-hollow rivet Aluminum alloy Affected zone Dynamic recrystallization