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Effect of scanning strategy on grain structure and crystallographic texture of Inconel 718 processed by selective laser melting

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Journal of Materials Science & Technology 2018年第10期34卷 1799-1804页

作者： H.Y. Wan Z.J. Zhou C.P. Li g.f. chen g.P. Zhang Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China School of Materials Science and Engineering University of Science and Technology of China Shenyang 110016 China Materials & Manufacturing Qualification group Corporate Technology Siemens Ltd. Beijing 100102 China

Two types of scanning strategies were adopted to study the effect of scanning strategy on grain structure and crystallographic texture of selective laser melted （SLM） Inconel 718. The results show that bidirec-tional scanning without and with a 90°-rotation for every layer produced the bimodal grain structure and the directional columnar grain structure, respectively. Controlling the heat flux direction between the successive layers via scanning strategy enabled the formation of such different grain structures. fur-thermore, when the 90°-rotation was applied, the competitive grain growth mechanism became more pronounced and the strong cube texture developed.

关键词： Selective laser melting Additive manufacturing Scanning strategy Texture grain structure

EffECT Of MICROSTRUCTURE CHANgE ON OXIDE fORMATION Of SPUTTERED Ni-3Cr-10Al NANOCRYSTALLINE COATINg

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Acta Metallurgica Sinica(English Letters) 1999年第6期12卷 0-0,0-0页

作者： g.f. chen and H Y Lou(State Key Laboratory for Corrosion and Protection, lnstitute of Corrosion and Protection of Metals, The Chinese Academy of Sciences, Shenyang 110015, China)

The microstructure change of sputtered Ni-3Cr-10Al nanocrystalline coating during oxidation in air at 900°C was observed and its eNct on oxide formation on the sputtered coating was studied. Twe results indicated that Ni3Al was segmpated during oxidation, on which Nio could be easily formcd. NiO could react with the trunsient γ-Al2O3 to form NiAl2O4 through solid reaction, whtch can be found on the oxide scale afer 200h oxidation. Thewtre, the oxide scale formed on sputtered Ni-3Cr10Al coating was not composed of a unltary layer of Al2 O3. Thc Al2O3 and NiAl2 O4 complex oxide scale bonded properly with substrate and showed gpod adhesion and good oxidation resistance.

关键词： oxidation Ni-3Cr-10Al nanocrystalline coating

The effects of local variations in conditions on carbon storage and release in the continental mantle

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National Science Review 2024年第6期11卷 22-36页

作者： Stephen f.foley Chunfei chen Dorrit E.Jacob School of Natural Sciences Macquarie University Research School of Earth Sciences Australian National University State Key Laboratory of geological Processes and Mineral Resources School of Earth Sciences China University of Geosciences

Recent advances indicate that the amount of carbon released by gradual degassing.f.om the mantle needs to be revised upwards, whereas the carbon supplied by plumes may have been overestimated in the *** in rock types and oxidation state may be very local and exert strong influences on carbon storage and release mechanisms. Deep subduction may be prevented by diapirism in thick sedimentary packages,whereas carbonates in thinner sequences may be subducted. Carbonates stored in the mantle transition zone will melt when they heat up, recognized by coupled stable isotope systems(e.g. Mg, Zn, Ca). There is no single ‘mantle oxygen fugacity’, particularly in the thermal boundary layer(TBL) and lowermost lithosphere, where very local mixtures of rock types coexist. Carbonate-rich melts from either subduction or melting of the uppermost asthenosphere trap carbon by redox freezing or as carbonate-rich dykes in this zone. Deeply derived, reduced melts may form further diamond reservoirs, recognized as polycrystalline diamonds associated with websteritic silicate minerals. Carbon is released by either edge-driven convection,which tears sections of the TBL and lower lithosphere down so that they melt by a mixture of heating and oxidation, or by lateral advection of solids beneath rifts. Both mechanisms operate at steps in lithosphere thickness and result in carbonate-rich melts, explaining the spatial association of craton edges and carbonate-rich magmatism. High-pressure experiments on individual rock types, and increasingly on reactions between rocks and melts, are fine-tuning our understanding of processes and turning up unexpected results that are not seen in studies of single rocks. future research should concentrate on elucidating local variations and integrating these with the interpretation of geophysical signals. global concepts such as average sediment compositions and a uniform mantle oxidation state are not appropriate for small-scale processes; an increa

关键词： lithospheric mantle carbonate melts deep carbon cycle craton destruction continental rifts

A predictive model for ethylene-mediated auxin and cytokinin patterning in the Arabidopsis root

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Plant Communications 2024年第7期5卷 120-137页

作者： Simon Moore george Jervis Jennifer f.Topping Chunli chen Junli Liu Keith Lindsey Department of Biosciences Durham UniversitySouth RoadDurham DH13LEUK Hubei Hongshan Laboratory College of Life Science and TechnologyHuazhong Agricultural UniversityWuhan 430070China National Key Laboratory for germplasm Innovation and Utilization for fruit and Vegetable Horticultural Crops Huazhong Agricultural UniversityWuhanHubei 430070China

The interaction between auxin and cytokinin is important in many aspects of plant *** measurements of both auxin and cytokinin concentration and reporter gene expression clearly show the coexistence of auxin and cytokinin concentration patterning in Arabidopsis root ***,in the context of crosstalk among auxin,cytokinin,and ethylene,little is known about how auxin and cytokinin concentration patterns simultaneously emerge and how they regulate each other in the Arabidopsis *** work utilizes a wide range of experimental observations to propose a mechanism for simultaneous patterning of auxin and cytokinin *** addition to revealing the regulatory relationships between auxin and cytokinin,this mechanism shows that ethylene signaling is an important factor in achieving simultaneous auxin and cytokinin patterning,while also predicting other experimental *** the mechanism with a realistic in silico root model reproduces experimental observations of both auxin and cytokinin *** made by the mechanism can be compared with a variety of experimental observations,including those obtained by our group and other independent experiments reported by other *** of these predictions include patterning of auxin biosynthesis rate,changes in PIN1 and PIN2 patterns in pin3,4,7 mutants,changes in cytokinin patterning in the pls mutant,PLS patterning,and various trends in different *** research reveals a plausible mechanism for simultaneous patterning of auxin and cytokinin concentrations in Arabidopsis root development and suggests a key role for ethylene pattern integration.

关键词： Arabidopsis root auxin patterning cytokinin patterning ethylene signaling in silico digital root spatiotemporal modeling

A refined representation method of the particle size distribution curve based on grading entropy

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Particuology 2024年第5期88卷 302-311页

作者： Xing Li Qun chen Zhaozhao Liu cheng Zhou chen Wang chen chen State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China

The particle size distribution(PSD)curve is an important expression of the basic properties of the *** characteristic parameters such as median particle size D_(50),effective particle size D_(10),and some combinations of characteristic parameters can only represent some points of the PSD curve,failing to represent all information of the PSD *** this paper,a fraction characteristic parameter f that could reflect the fraction size variation of the PSD curve was introduced based on grading *** a new presentation method of the A-B-f three parameters was proposed for a refined representation of the PSD *** was found that the newly constructed model not only better represents the differences in the width of PSD curves but also has a higher sensitivity than the A-B two-parameter model proposed by Lő*** PSD curves with similar distributions,the new presentation method has a higher degree of discrimination than that of the D_(50)-C_(u)-C_(c) three-parameter or the four-parameter combination g_(c) proposed by ***,the application of this new method in describing the spatial nonuniformity distribution of depositions and predicting the soil hydraulic conductivity was *** research results can provide a reference for the refined representation of PSD curves.

关键词： grading entropy Particle size distribution curve Refined representation

Rescattering of stimulated Raman side scattering in nonuniform plasmas

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Matter and Radiation at Extremes 2024年第5期9卷 68-76页

作者： S.Tan Q.Wang Y.chen W.B.Yao C.Z.Xiao J.f.Myatt School of Physics and Electronics Hunan UniversityChangsha 410082China Institute of Applied Physics and Computational Mathematics Beijing 100094China School of Electrical and Information Engineering Anhui University of Science and TechnologyHuainanAnhui 232001China Department of Electrical and Computer Engineering University of Alberta9211116 St.NWEdmontonAlberta T6G 1H9Canada

Rescattering of stimulated Raman side scattering(SRSS)is observed for the first time via two-dimensional(2D)particle-in-cell(PIC)*** construct a theoretical model for the rescattering process,which can predict the region of occurrence of mth-order SRSS and estimate its *** rescattering process is identified by the 2D PIC simulations under typical conditions of a direct-drive inertial confinement fusion *** electrons produced by second-order SRSS propagate nearly perpendicular to the density gradient and gain nearly the same energy as in first-order SRSS,but there is no cascade acceleration to produce superhot *** studies for a wide range of ignition conditions show that SRSS and associated rescatterings are robust and important processes in inertial confinement fusion.

关键词： nonuniform acceleration scattering

Application of novel constrained friction processing method to produce fine grained biomedical Mg-Zn-Ca alloy

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Journal of Magnesium and Alloys 2024年第2期12卷 516-529页

作者： Ting chen Banglong.f. Junjun Shen Uceu f.H.R.Suhuddin Björn Wiese Yuanding Huang Min Wang Jorge f.dos Santos Jean Pierre Bergmann Benjamin Klusemann Solid State Materials Processing Institute of Material MechanicsHelmholtz-Zentrum HereonMax-Planck-Str.1Geesthacht 21502Germany functional Magnesium Materials Institute of Metallic BiomaterialsHelmholtz-Zentrum HereonMax-Planck-Str.1Geesthacht 21502Germany Shanghai Key Laboratory of Materials Laser Processing and Modification Shanghai Jiao Tong UniversityDongchuan Road 800Shanghai 200240China Applied Materials and Manufacturing Energy and Environment DivisionPacific Northwest National LaboratoryPO Box 999RichlandWA 99352USA Production Technology group Technisiche Universität IlmenauGustav-Kirchhoff-Platz 2Ilmenau 98693Germany Institute for Production Technology and Systems Leuphana University of LüneburgUniversitätsallee 1Lüneburg 21335Germany

In order to obtain Mg alloys with fine microstructures and high mechanical performances,a novel friction-based processing method,name as“constrained friction processing(CfP)”,was *** CfP,defect-free Mg-Zn-Ca rods with greatly refined grains and high mechanical properties were *** to the previous as-cast microstructure,the grain size was reduced from more than 1 mm to around 4μm within 3 s by a single process *** compressive yield strength was increased by 350%while the ultimate compressive strength by 53%.According to the established material flow behaviors by“tracer material”,the plastic material was transported by shear *** the base material to the rod,the material experienced three stages,*** by the tool,upward flow with additional tilt,followed by upward *** microstructural evolution was revealed by“stop-action”*** microstructural development at regions adjacent to the rod is mainly controlled by twinning,dynamic recrystallization(DRX)as well as particle stimulated nucleation,while that within the rod is related to DRX combined with grain growth.

关键词： Constrained friction processing Magnesium alloys Microstructure Mechanical properties grain refinement Plastic deformation

Durable and enhanced immunity against SARS-CoV-2 elicited by manganese nanoadjuvant formulated subunit vaccine

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Signal Transduction and Targeted Therapy 2024年第1期9卷 47-50页

作者： Mengyu guo Mingjing Cao Jiufeng Sun Ziwei chen Xin Wang Lianpan Dai george f.gao Yuliang Zhao Yaling Wang Chunying chen CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety&CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology of ChinaBeijingChina guangdong Provincial Institute of Public Health Guangdong Provincial Center for Disease Control and PreventionGuangzhouChina CAS Key Laboratory of Pathogen Microbiology and Immunology Institute of MicrobiologyBeijingChina

Dear editor,Vaccines are the most efficient and effective means to prevent infectious diseases,but improving the long-term protective efficacy is still a major challenge in contemporary vaccine development.1 The waning immunity varies depending on the diversification of the pathogen and the number of booster doses.1 Strategies to overcome this warrant is using adjuvants that amplify the immune response,and drive the production of memory B and T cells or long-lived plasma cells that recognize the pathogen for durable protection.2–4 Although existing adjuvants have achieved promising results,research on generating durable protective immunity is lacking in promoting vaccine development and staying ahead of global pandemics such as coronavirus disease 2019(COVID-19).The precisely designed nanoadjuvants can enhance lymph node targeting and increase antigenpresenting cell(APCs)uptake,achieving the co-delivery of adjuvants and antigens and activating innate and adaptive immune responses.5 Previously,we reported a manganese nanoadjuvant(MnARK)and receptor-binding domain(RBD)monomer antigen formulated nanovaccine.6 MnARK transported antigens to lymph nodes,activated the STINg pathway,elicited strong neutralizing abilities and increased immune memory T cell percentage against the infection of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).6 Regarding the long-term protection potential of MnARK for subunit vaccine development,we further explored the durable immune regulation abilities of MnARK to a SARS-CoV-2 RBD dimer antigen,which has been used in an approved COVID-19 subunit vaccine Zf2001 with aluminum adjuvant(alum).7,8 TEM result revealed that RBD dimer could interact with BSA on MnARK surface and epitope can be well preserved(Supplementary fig.1a).The size and zeta potential of MnARK-RBD dimer nanovaccine was~58 nm and-14 mV,respectively(Supplementary fig.1b,c).

关键词： manganese immunity protective

Precipitation transformation pathway and mechanical behavior of nanoprecipitation strengthened fe-Mn-Al-C-Ni austenitic low-density steel

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Journal of Materials Science & Technology 2024年第7期174卷 157-167页

作者： Y.f.An X.P.chen L.Mei P.Ren D.Wei W.Q.Cao College of Materials Science and Engineering Chongqing UniversityChongqing 400044China guangxi Engineering Research Center for Characteristic Metallic Powder Materials School of Electronic EngineeringGuangxi University of Science and TechnologyLiuzhou 545006China Central Iron&Steel Research Institute Beijing 100081China

Precipitation strengthening has been widely adopted in austenitic low-density steel owing to excellent hardened *** approach generally employs the coherentκ′carbides and non-coherent B2 *** the precipitation transformation pathway is decisive for further optimizing the microstructures under specific engineering ***,the detailed precipitation sequence of fe-28Mn-11Al-1C-5Ni(wt%)austenitic low-density steel as well as its influence on mechanical prop-erties during aging process is systematically *** results reveal that nano-sizedκ′carbides domains(2 nm)exist in the solution-treated *** aging at 500℃for 1 h,the cuboidalκ′carbides(15-20 nm)uniformly disperse in austenite ***,after aging at 700℃for 15 min,the coarsenκ′carbides(30-35 nm)inhomogeneously distribute and align preferentially along the〈100〉***,extending the aging time to 60 min,the needle-type B2 particles replace theκ′carbides due to the enrichment of Ni elements at the phase boundaries among the austenite andκ′*** aging at 900℃,κ′carbides entirely dissolve into the austenite matrix,and the intragranular B2 particles are the sole precipitates in the austenite matrix and follow the K-S orientation relationship with *** work hardening capability seriously deteriorates due to the shearing ofκ′carbides by gliding *** the intragranular B2 particles preserve excellent work hardening rate by dislocations bow-out *** present work is meaningful for guiding the design of new generation dual-nano precipitation austenitic lightweight steel.

关键词： Lightweight steel κ′-carbides B2 particles Work hardening capability