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Effect of Direct Aging on Corrosion Behavior of AlSi10Mg Alloy Fabricated by Laser Powder Bed Fusion

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 266-282页

作者： zhen Zhang Zhanyong Zhao Xiaofeng li Beibei Wang Peikang Bai Shanxi Key Laboratory of Controlled Metal Solidification and Precision Manufacturing School of Materials Science and EngineeringNorth University of ChinaTaiyuan030051China Technical Center Taiyuan Iron and Steel(Group)Co.LtdTaiyuan030003China School of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan030024China

Effect of direct aging of 170℃on corrosion behavior of laser powder bed fused AlSi10Mg(LPBF-AlSi10Mg)was studied by microstructure analysis,electrochemical analysis and X-ray photoelectron *** results show that direct aging of 170℃has little effect on melt pool and Si cellular structure,but promotes the precipitation of nano-Si particles and releases the residual *** increasing aging time from 0 to 4 h to 24 h,the corrosion property of the LPBF-AlSi10Mg is deteriorated,which is evidenced by increased corrosion current density and decreased pitting potential and polarization *** increasing the aging time,the thickness of the oxide film formed on surface of the LPBF-AlSi10Mg *** Si content of the oxide film of the sample aging for 4 h is the lowest,9.42 at.%,and it is the highest,18.62 at.%,for the sample aging for 24 *** electrochemical noise analysis reveals that the middle-frequency contribution of the Hilbert spectrum is responsible for the deteriorated corrosion performance,which corresponds to metastable pitting initiated by nano-Si particles.

关键词： Laser powder bed fusion AlSi10Mg Direct aging Corrosion

Evolution of MnO–SiO2–Al_(2)O_(3)–MgO inclusions during heat treatment at 1100℃

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Journal of Iron and Steel Research International 2024年第5期31卷 1221-1231页

作者： Xu-bo Lei Jian-li li qiang Zeng Hang-yu Zhu Yue Yu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430081HubeiChina Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan430081HubeiChina

To investigate the evolutionary behavior of the MnO–SiO_(2)–Al_(2)O_(3)–MgO inclusions during heat treatment,water quenched samples were isothermally held at 1100°C for 120 min in Ar and air atmosphere,and the obtaining samples were analyzed by X-ray diffraction,scanning electron microscopy and energy dispersive *** showed that 3MnO·Al_(2)O_(3)·3SiO_(2)and MnO·SiO_(2)were detected in the 5 wt.%MgO system after isothermal holding in Ar atmosphere,while MgO·Al_(2)O_(3),MnO·SiO_(2)and Mn7O8·SiO4 were detected in air *** evolutionary behavior of the 10,15 and 20 wt.%MgO systems after isothermal holding in different atmosphere were *** affected the solid phase transformation of the low MgO content *** calculation results of FactSage 8.1 showed that MgO·Al_(2)O_(3)was formed in the 5 wt.%MgO system with air *** solid phase transformation was accompanied by grain coarsening during the isothermal holding *** differences in the solid phase transformation in different atmosphere of the 5 wt.%MgO system indicated that it was a gas-phase transport grain coarsening *** enrichment of Al element in the liquid phase region at the grain edges,the homogeneous distribution of Mg element and the disappearance of the liquid phase within the crystal revealed that other MgO content systems were liquid–solid transport grain coarsening mechanism.

关键词： Evolution Glassy phase Inclusion Heat treatment MgO·Al_(2)O_(3)

Central cell:the key to determine persistent pollen tube attraction or termination

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Science China(life Sciences) 2024年第9期67卷 2030-2032页

作者： Jiang-Guo Meng Shi-zhen li Hong-Ju li Center for Developmental Biology Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation Integrative Science Center of Germplasm Creation Western China(Chongqing)Science CitySchool of Life SciencesSouthwest UniversityChongqing400715 China Key Laboratory of Seed Innovation Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China Center for Molecular Agrobiology Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China

Most eukaryotic species depend on sexual reproduction,characterized by fertilization,to produce a new *** process requires the transfer of sperm(male gamete),containing half of the genetic information,from the male to the egg cell(female gamete),which holds half of the maternal genome,within the female reproductive *** strategies have been evolved to ensure fertilization success in plants.

关键词： organs termination holds

Dynamic Crosslinked Phosphorescent Poly(vinyl alcohol)-Terpyridine Films with Enhanced Mechanical Properties and Tunable Shape Memory

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Chinese Journal of Polymer Science 2024年第10期42卷 1595-1601,I0015页

作者： Meng Wei Wei-Hao Feng Chen Yu zhen-Yi Jiang Guang-qiang Yin Wei Lu Tao Chen Key Laboratory of Advanced Marine Materials Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo315201China School of Chemical Sciences University of Chinese Academy of SciencesBeijing100049China School of Materials Science and Chemical Engineering Ningbo UniversityNingbo315211China

Achieving versatile room temperature phosphorescence(RTP)materials,especially with tunable mechanical properties and shape memory is attractive and essential but rarely ***,a strategy was reported to realize multi-functional RTP films with multicolor fluorescence,ultralong afterglow,adjustable mechanical properties,and shape memory through the synergistic dynamic interaction of lanthanide(Ln~Ⅲ)-terpyridine coordination,borate ester bonds,and hydrogen bondings in a poly(vinyl alcohol)(PVA)*** varying the amount of borax,the mechanical properties of the films could be finely controlled due to the change of crosslinking degree of dynamic borate ester bonds in *** assembly and disassembly of borate ester bonds upon the trigger of borax and acid were applied as reversible linkage to achieve programmable shape memory *** addition,the films displayed both fascinating multicolor fluorescence and ultralong afterglow characteristics due to the presence of Ln III doping and confinement of terpyridine in *** study provides a new avenue to impart modulable mechanical strength and shape memory to RTP materials.

关键词： Room temperature phosphorescence materials Dynamic bonds Multicolor fluorescent Tunable mechanical properties Shape memory

A novel method for AFRPs burrs removal:Principle of mechanochemo-induced fiber fracture

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Chinese Journal of Aeronautics 2024年第7期37卷 522-538页

作者： Jie XU Bo li Pingfa FENG qiang WANG Feng FENG Division of Advanced Manufacturing Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Changhe Aircraft Industry(Group)Co.Ltd Jingdezhen 333000China

Burrs generated during the machining of Aramid-Fiber-Reinforced Composites(AFRPs)pose a challenge for the production efficiency of aircraft and helicopter housing *** studies have generally attempted to suppress burrs by referring to delamination suppression *** contrast to stratification,burrs are remediable machining *** such,a mechanochemical method with burrs trimming technological strategy are implemented to effectively combat ***,we clarify the mechanism by which aramid fibers cannot be cut off using analytical and numerical *** addition,the mechanism of fiber fracture with Modified Polyurethane Reactive Polymer(M-PUR),and development of anti-burr devices(thermostatic adhesive sealed generator)are ***,the experimental results show that the reduction rate in burr length is 87%-91%through the mechanochemical *** method not only opens a new avenue to solve the burr problem of aramid fibers but also builds an interdisciplinary bridge between polymer science and composite machining.

关键词： Mechanochemical method Burrs Orthogonal cutting Aramid fiber-reinforced composites Milling

Design of integral sliding mode guidance law based on disturbance observer

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Journal of Systems Engineering and Electronics 2024年第1期35卷 186-194页

作者： ZHOU Jianping ZHANG Wenjie ZHOU Hang li qiang XIA Qunli School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China School of Informatic Engineering Mianyang Techers’CollegeMianyang 62100China Beijing Institute of Electronic System Engineering Beijing 100854China Beijing Institute of Space Long March Vehicle Beijing 100076China

With the increasing precision of guidance,the impact of autopilot dynamic characteristics and target maneuvering abilities on precision guidance is becoming more and more *** order to reduce or even eliminate the autopilot dynamic operation and the target maneuvering influence,this paper suggests a guidance system model involving a novel integral sliding mode guidance law(ISMGL).The method utilizes the dynamic characteristics and the impact angle,combined with a sliding mode surface scheme that includes the desired line-ofsight angle,line-of-sight angular rate,and second-order differential of the angular *** the same time,the evaluation scenario considere the target maneuvering in the system as the external disturbance,and the non-homogeneous disturbance observer estimate the target maneuvering as a compensation of the guidance *** proposed system’s stability is proven based on the Lyapunov stability *** simulations reveale that ISMGL effectively intercepted large maneuvering targets and present a smaller miss-distance compared with traditional linear sliding mode guidance laws and trajectory shaping guidance ***,ISMGL has a more accurate impact angle and fast convergence speed.

关键词： disturbance observer pilot dynamics integral sliding mode impact angle constraint maneuvering target

Molecular dynamics simulations in hydrogel research and its applications in energy utilization: A review

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Energy Reviews 2024年第3期3卷 15-29页

作者： liangyu li zhen liu Ronghui Qi Key Laboratory of Enhanced Heat Transfer and Energy Conservation of Education Ministry School of Chemistry and Chemical EngineeringSouth China University of TechnologyGuangzhou510640China

Hydrogels are soft,highly absorbent and water-retaining polymers that are widely used in energy *** dynamics(MD)simulation is powerful in exploring micro/nano mechanisms and can assist material regulation and experimental *** review summarizes recent MD simulations on the composition and structure characteristics of physically and chemically crosslinked hydrogels,focusing on the functionalities such as mechanical properties,heat transfer performance,hygroscopic properties and photocatalytic applications required in the energy conversion *** fundamentals of MD simulations are also introduced,along with common modeling procedures for *** review showed that MD simulations can visually display molecular-scale changes during cross-linking and absorption processes,thereby predicting changes in intermolecular interactions and associated microstructural *** for future research include constructing hydrogel networks that can be experimentally verified,and developing appropriate molecular force fields under various operating *** quantum mechanics or coarse-graining methods in MD simulations further broaden its application into electronic or mesoscopic *** with machine learning,finite element or lattice Boltzmann methods may be also promising as it can be used to reveal the influence of 3D pores within *** study aims to promote the use of MD simulations in exploring characteristics and mechanisms of hydrogel and other polymer materials in energy utilization.

关键词： Hydrogel Functionality Energy conversion Molecular dynamics simulation Network structure Intermolecular interaction

Generation and regulation of electromagnetic pulses generated by femtosecond lasers interacting with multitargets

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Nuclear Science and Techniques 2024年第1期35卷 96-107页

作者： Ya-Dong Xia De-Feng Kong qiang-You He zhen Guo Dong-Jun Zhang Tong Yang Hao Cheng Yu-Ze li Yang Yan Xiao liang Ping Zhu Xing-Long Xie Jian-qiang Zhu Ting-Shuai li Chen lin Wen-Jun Ma Xue-Qing Yan State Key Laboratory of Nuclear Physics and Technology and Key Laboratory of HEDP of the Ministry of EducationCAPTPeking UniversityBeijing 100871China Beijing Laser Acceleration Innovation Center Beijing 101407China Institute of Guangdong Laser Plasma Technology Guangzhou 510540China National Laboratory on High Power Laser and Physics Shanghai Institute of Optics and FineChinese Academy of SciencesShanghai 201800China School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 611731China

Ultrashort and powerful laser interactions with a target generate intense wideband electromagnetic pulses(EMPs).In this study,we report EMPs generated by the interactions between petawatt(30 fs,1.4×10^(20) W/cm^(2))femtosecond(fs)lasers with metal flat,plastic flat,and plastic nanowire-array(NWA)*** analyses are conducted on the EMPs in terms of their spatial distribution,time and frequency domains,radiation energy,and *** results indicate that EMPs from metal targets exhibit larger amplitudes at varying angles than those generated by other types of targets and are enhanced significantly for NWA *** a plastic target holder and increasing the laser focal spot can significantly decrease the radiation energy of the ***,the composite shielding materials indicate an effective shielding effect against *** simulation results show that the NWA targets exert a collimating effect on thermal electrons,which directly affects the distribution of *** study provides guidance for regulating EMPs by controlling the laser focal spot,target parameters,and target rod material and is beneficial for electromagnetic-shielding design.

关键词： Electromagnetic pulses Laser plasma interaction Electromagnetic shielding Electron distribution

Autophagy and its role in gastrointestinal diseases

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World Journal of Gastroenterology 2024年第36期30卷 4014-4020页

作者： Bo-Zong Shao Wen-Gang Zhang zhen-Yu liu En-qiang linghu Department of Gastroenterology First Medical Center of Chinese People’s Liberation Army General HospitalBeijing 100853China

Gastrointestinal disorders encompass a spectrum of conditions affecting various organs within the digestive system,such as the esophagus,stomach,colon,rectum,pancreas,liver,small intestine,and bile *** role of autophagy in the etiology and progression of gastrointestinal diseases has garnered significant *** paper seeks to evaluate the impact and mechanisms of autophagy in gastrointestinal disorders by synthesizing recent research ***,we delve into inflammation-related gastrointestinal conditions,including ulcerative colitis,Crohn’s disease,and pancreatitis,as well as gastrointestinal cancers such as esophageal,gastric,and colorectal ***,we provide commentary on a recent publication by Chang et al in the World Journal of *** objective is to offer fresh perspectives on the mechanisms and therapeutic approaches for these gastrointestinal *** review aims to offer new perspectives on the mechanisms and therapeutic strategies for gastrointestinal disorders by critically analyzing relevant *** discussed,the role of autophagy in gastrointestinal diseases is complex and,at times,*** harness the full therapeutic potential of autophagy in treating these conditions,more in-depth research is imperative.

关键词： Autophagy Inflammation Cancer Inflammatory bowel disease Pancreatitis