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Effects of cooling rate on microstructure and microhardness of directionally solidified Galvalume alloy

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China Foundry 2024年第3期21卷 213-220页

作者： Ji-peng Li De-gao Qiao Jian Li Xiao-yang luo Peng Peng Xian-tao yan Xu-dong Zhang Gansu Jiu Steel Group Hongxing Iron and Steel Co. Ltd.Jiayuguan 735111GansuChina School of Materials and Energy Lanzhou UniversityLanzhou 730000China

The influences of cooling rate on the phase constitution,microstructural length scale,and microhardness of directionally solidified Galvalume(Zn-55Al-1.6Si)alloy were investigated by directional solidification experiments at different withdrawal speeds(5,10,20,50,100,200,and 400μm·s^(-1)).The results show that the microstructure of directionally solidified Galvalume alloys is composed of primary Al dendrites,Si-rich phase and(Zn-Al-Si)ternary eutectics at the withdrawal speed ranging from 5 to 400μm·s^(-1).As the withdrawal speed increases,the segregation of Si element intensifies,resulting in an increase in the area fraction of the Si-rich *** addition,the primary Al dendrites show significant refinement with an increase in the withdrawal *** relationship between the primary dendrite arm spacing(λ_(1))and the thermal parameters of solidification is obtained:λ_(1)=127.3V^(-0.31).Moreover,as the withdrawal speed increases from 5 to 400μm·s^(-1),the microhardness of the alloy increases from 90 HV to 151 *** is a combined effect of grain refinement and second-phase strengthening.

关键词： Galvalume alloy directional solidification microstructure length scale microhardness

Independent dual beams generated by array element division in integrated optical phased arrays

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Chinese Optics Letters 2024年第7期22卷 35-41页

作者： Guihan Wu Yu xin Lemeng Leng Xiang Ji Shichong yang Kaifei Tang Quan luo Hongsheng luo Jinshan Su Wei Jiang College of Engineering and Applied Sciences Nanjing UniversityNanjing 210023China National Laboratory of Solid-State Microstructures Nanjing 210093China Key Laboratory of Intelligent Optical Sensing and Manipulation Ministry of EducationNanjing UniversityNanjing 210023China Jiangsu Key Laboratory of Artificial Functional Materials Nanjing UniversityNanjing 210023China Key Laboratory of Vibration Signal Capture and Intelligent Processing Yili Normal UniversityIli 835000China

Optical phased arrays(OPAs)have broad application prospects due to their advanced capability in beamforming and *** this work,we achieve independent dual beams in the far field by dividing the array elements of the OPA,with the maximum scanning range reaching 100°.Based on the working principle of OPAs,theoretical considerations of such multibeam generation are presented.A phase data allocation approach for OPAs in the presence of fabrication-induced random phase variation is *** of large ensembles of OPAs with various levels of random residual phase errors have been conducted to help analyze the *** approach can help OPAs realize multi-beams for light detection and ranging(LiDAR).

关键词： optical phased arrays beamforming phase error calibration array element division

Interfacial Electronic Modulation of Dual-Monodispersed Pt–Ni_(3)S_(2) as Efficacious Bi-Functional Electrocatalysts for Concurrent H_(2) Evolution and Methanol Selective Oxidation

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Nano-Micro Letters 2024年第4期16卷 415-431页

作者： Qianqian Zhao Bin Zhao xin Long Renfei Feng Mohsen Shakouri Alisa Paterson Qunfeng Xiao Yu Zhang Xian‑Zhu Fu Jing‑Li luo Shenzhen Key Laboratory of Energy Electrocatalytic Materials Shenzhen Key Laboratory of Polymer Science and TechnologyGuangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen 518060People’s Republic of China Canadian Light Source Inc. SaskatoonSK S7N 0X4Canada Instrumental Analysis Center of Shenzhen University(Lihu Campus) Shenzhen UniversityShenzhen 518055People’s Republic of China

Constructing the efficacious and applicable bifunctional electrocatalysts and establishing out the mechanisms of organic electro-oxidation by replacing anodic oxygen evolution reaction(OER) are critical to the development of electrochemicallydriven technologies for efficient hydrogen production and avoid CO_(2) emission. Herein, the hetero-nanocrystals between monodispersed Pt(~ 2 nm) and Ni_(3)S_(2)(~ 9.6 nm) are constructed as active electrocatalysts through interfacial electronic modulation, which exhibit superior bi-functional activities for methanol selective oxidation and H_(2) generation. The experimental and theoretical studies reveal that the asymmetrical charge distribution at Pt–Ni_(3)S_(2) could be modulated by the electronic interaction at the interface of dual-monodispersed heterojunctions, which thus promote the adsorption/desorption of the chemical intermediates at the interface. As a result, the selective conversion from CH_(3)OH to formate is accomplished at very low potentials(1.45 V) to attain 100 m A cm^(-2) with high electronic utilization rate(~ 98%) and without CO_(2) emission. Meanwhile, the Pt–Ni_(3)S_(2) can simultaneously exhibit a broad potential window with outstanding stability and large current densities for hydrogen evolution reaction(HER) at the cathode. Further, the excellent bi-functional performance is also indicated in the coupled methanol oxidation reaction(MOR)//HER reactor by only requiring a cell voltage of 1.60 V to achieve a current density of 50 m A cm^(-2) with good reusability.

关键词： Dual-monodispersed heterostructure Electronic interactive modulation Reaction mechanism Methanol oxidation reaction Hydrogen generation

Strengthening and control of second-phase particle precipitation in ferritic/austenitic/martensitic heat-resistant alloys:a review

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Journal of Iron and Steel Research International 2024年第1期31卷 3-23页

作者： Xue-cheng Peng Han-jie Guo xin-fang Zhang Yi-wa luo Ye Sun Jing Guo Rong-guang yang Xiao-dan Zheng School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing100083China Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials University of Science and Technology Beijing(USTB)Beijing100083China Beijing Shougang Gitane New MATERIALS Co. Ltd.Beijing102206China

Heat-resistant alloys with excellent mechanical properties are widely used in various fields,and further improvement in their properties is essential to meet the requirements in new-generation advanced supercritical boilers,nuclear reactors,superheaters,and other new materials *** effectively enhance the comprehensive performance of heat-resistant alloys,second-phase particle strengthening has been widely studied,and in the face of different service envi-ronments of advanced heat-resistant steels,the selection of suitable second-phase particles is essential to maximize the performance of these *** this end,three major types of reinforcing phases in heat-resistant alloys such as carbides,rare earth oxides,and intermetallic compounds are summarized.A comparative analysis of the precipitation behavior of the reinforcing phases with different types as well as the risks and means of controlling their use in service,is *** parameters for the application of various types of second-phase particles in heat-resistant alloys are provided to support the design and preparation of new ultrahigh-performance heat-resistant alloys.

关键词： Heat-resistant alloy Second-phase particle Carbide Rare earth oxide Intermetallic compound Strengthening

Potential-dependent insights into the origin of high ammonia yield rate on copper surface via nitrate reduction:A computational and experimental study

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Journal of Energy Chemistry 2024年第9期96卷 272-281页

作者： yangge Guo Nannan Sun Liuxuan luo Xiaojing Cheng Xueying Chen Xiaohui yan Shuiyun Shen Junliang Zhang Institute of Fuel Cells School of Mechanical EngineeringMOE Key Laboratory of Power&Machinery EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Chemical and Biological Engineering The Hong Kong University of Science and TechnologyClear Water BayKowloon 999077Hong KongChina Paris Elite Institute of Technology Shanghai Jiao Tong UniversityShanghai 200240China

Focusing on revealing the origin of high ammonia yield rate on Cu via nitrate reduction(NO3RR),we herein applied constant potential method via grand-canonical density functional theory(GC-DFT)with implicit continuum solvation model to predict the reaction energetics of NO3RR on pure copper surface in alkaline *** potential-dependent mechanism on the most prevailing Cu(111)and the minor(100)and(110)facets were established,in consideration of NO_(2)_(−),NO,NH_(3),NH_(2)OH,N_(2),and N_(2)O as the main *** computational results show that the major Cu(111)is the ideal surface to produce ammonia with the highest onset potential at 0.06 V(until−0.37 V)and the highest optimal potential at−0.31 V for ammonia production without kinetic obstacles in activation energies at critical *** other minor facets,the secondary Cu(100)shows activity to ammonia from−0.03 to−0.54 V with the ideal potential at−0.50 V,which requires larger overpotential to overcome kinetic activation energy *** least Cu(110)possesses the longest potential range for ammonia yield from−0.27 to−1.12 V due to the higher adsorption coverage of nitrate,but also with higher tendency to generate di-nitrogen *** evaluations on commercial Cu/C electrocatalyst validated the accuracy of our proposed *** most influential(111)surface with highest percentage in electrocatalyst determined the trend of ammonia *** specific,the onset potential of ammonia production at 0.1 V and emergence of yield rate peak at−0.3 V in experiments precisely located in the predicted potentials on Cu(111).Four critical factors for the high ammonia yield and selectivity on Cu surface via NO3RR are summarized,including high NO3RR activity towards ammonia on the dominant Cu(111)facet,more possibilities to produce ammonia along different pathways on each facet,excellent ability for HER inhibition and suitable surface size to suppress di-nitrogen species formation at high nitrate cove

关键词： Nitrate reduction to ammonia Copper surface Density functional theory Constant electrode potential method Experimental validation

All-trans retinoic acid alleviates transmissible gastroenteritis virus-induced intestinal inflammation and barrier dysfunction in weaned piglets

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Journal of Animal Science and Biotechnology 2024年第3期15卷 1131-1144页

作者： Junning Pu Daiwen Chen Gang Tian Jun He Ping Zheng Zhiqing Huang Xiangbing Mao Jie Yu Yuheng luo Junqiu luo Hui yan Aimin Wu Bing Yu Institute of Animal Nutrition Sichuan Agricultural UniversityChengdu 611130SichuanPeople’s Republic of China Key Laboratory of Animal Disease-Resistance Nutrition Ministry of EducationMinistry of Agriculture and Rural AffairsKey Laboratory of Sichuan Province611130 ChengduSichuanPeople’s Republic of China

Background Transmissible gastroenteritis virus(TGEV)is one of the main pathogens causing severe diarrhea of *** pathogenesis of TGEV is closely related to intestinal ***-trans retinoic acid(ATRA)is the main active metabolite of vitamin A,which has immunomodulatory and anti-inflammatory ***,it is unclear whether ATRA can alleviate TGEV-induced intestinal inflammation and barrier dysfunction in *** study aimed to investigate the effects of ATRA on growth performance,diarrhea,intestinal inflammation and intesti-nal barrier integrity of TGEV-challenged *** In a 19-d study,32 weaned piglets were randomly divided into 4 treatments:Control group(basal diet),TGEV group(basal diet+TGEV challenge),TGEV+ATRA5 group(basal diet+5 mg/d ATRA+TGEV challenge)and TGEV+ATRA15 group(basal diet+15 mg/d ATRA+TGEV challenge).On d 14,piglets were orally administered TGEV or the sterile *** Feeding piglets with 5 and 15 mg/d ATRA alleviated the growth inhibition and diarrhea induced by TGEV(P<0.05).Feeding piglets with 5 and 15 mg/d ATRA also inhibited the increase of serum diamine oxidase(DAO)activ-ity and the decrease of occludin and claudin-1 protein levels in jejunal mucosa induced by TGEV,and maintained intestinal barrier integrity(P<0.05).Meanwhile,5 mg/d ATRA feeding increased the sucrase activity and the expres-sions of nutrient transporter related genes(GLUT2 and SLC7A1)in jejunal mucosa of TGEV-challenged piglets(P<0.05).Furthermore,5 mg/d ATRA feeding attenuated TGEV-induced intestinal inflammatory response by inhibit-ing the release of interleukin(IL)-1β,IL-8 and tumor necrosis factor-α(TNF-α),and promoting the secretion of IL-10 and secretory immunoglobulin A(sIgA)(P<0.05).Feeding 5 mg/d ATRA also down-regulated the expressions of Toll-like receptors and RIG-I like receptors signaling pathway related genes(TLR3,TLR4,RIG-I,MyD88,TRIF and MAVS)and the phosphorylation level of nuclear factor-κB-p65(NF-κB p65),and

关键词： All-trans retinoic acid Inflammation Intestinal barrier Piglets Transmissible gastroenteritis virus

Lightweight foam-like nitrogen-doped carbon nanotube complex achieving highly efficient electromagnetic wave absorption

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Journal of Materials Science & Technology 2024年第1期168卷 114-123页

作者： Zongcheng Li Jin Liang Zhiheng Wei xin Cao Jiahui Shan Chunwei Li Xiaoyi Chen Dong Zhou Ruizhe xing Chunjia luo Jie Kong MOE Key Lab of Materials Physics and Chemistry in Extraordinary Conditions Shaanxi Key Laboratory of Macromolecular Science and TechnologySchool of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Key laboratory of Flexible Electronics of Zhejiang Province Ningbo Institute of Northwestern Polytechnical UniversityNingbo 315103China Polymer Materials and Engineering Department School of Materials Science and EngineeringChang’an UniversityXi’an 710064China

With the increased electromagnetic wave(EMW)threat to military and human health,the develop-ment of EMW-absorbing materials is ***-organic framework derivatives containing magnetic nanoparticles and a carbon matrix are potential candidates for designing efficient EMW-absorbing ***,a zeolitic imidazolate framework-67(ZIF-67)-embedded three-dimensional melamine foam is pyrolyzed to afford carbon foam-based nitrogen-doped carbon nanotube composites,named 3D foam-like CoO/Co/*** CoO/Co particles are confined in the dielectric carbon nanotube *** carbon nanotubes provide considerable conductive loss,while CoO/Co magnetic particles are con-ducive to providing magnetic loss and adjusting impedance ***,the numerous defect structures introduced by heteroatomic doping(nitrogen)cause dipole polarization and simultaneously adjust impedance ***,the unique porous nanotube structure promotes multiple re-flections and scattering of EMWs,further optimizing impedance ***/Co/N-CNTs composites exhibit a minimum reflection loss of−52.3 dB at a matching thickness of 2.0 mm,while the correspond-ing effective absorption bandwidth is 5.28 GHz at a matching thickness of 2.2 *** study reports a novel approach to fabricating a lightweight high-performance EMW-absorbing material.

关键词： Lightweight porous carbon materials Carbon nanotubes CoO/Co magnetic particles Electromagnetic synergistic effect Impedance matching

New insights in nano-copper chromite catalyzing ultrafine AP:Evaluation of dispersity and mixing uniformity

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Defence Technology（防务技术） 2024年第2期32卷 120-133页

作者： Yong Kou Peng luo Lei Xiao yanping xin Guangpu Zhang Yubing Hu Junqing yang Hongxu Gao Fengqi Zhao Wei Jiang Gazi Hao National Special Superfine Powder Engineering Research Center of China School of Chemistry and Chemical EngineeringNanjing University of Science and TechnologyNanjing210094China Xi'an North Huian Chemical Industry Co.Ltd Xi'an710302China Xi'an Modern Chemistry Research Institute Xi'an710065China

Improving the application of nanomaterials has always been a research hotspot in the field of energetic materials(EMs)due to their obvious catalytic effect on the EMs,especially the uniformly dispersed ***,few studies have reported the dispersion of *** this study,the dispersity and mixing uniformity of nano-CuCr_(2)O_(4)was evaluated based on the difference of solid UV light absorption between the nano-catalytic materials and *** nano-CuCr_(2)O_(4)/ultrafine AP composites with different dispersity of nano-CuCr_(2)O_(4)were prepared by manual grinding and mechanical grinding with different grinding strength and griding *** then,the absorbance of different samples at 212 nm was obtained by solid UV testing due to the high repeatability of the absorbance at 210-214 nm for three parallel experiments,and the dispersity of different samples was calculated through the established difference ***,the samples were characterized by XRD,IR,SEM,EDS,DSC and TG-MS,which confirmed that different mixing methods did not change the structure of the samples(XRD and IR),and the mixing uniformity improved with the increase of grinding strength and grinding time(SEM and EDS).The scientificity and feasibility of the difference equation were further verified by *** dispersity of nano-CuCr_(2)O_(4)exhibits a positive intrinsic relationship with its catalytic performance,and the uniformly dispersed nano-CuCr_(2)O_(4)significantly reduces the thermal decomposition temperature of ultrafine AP from 367.7 to 338.8℃.The TG-MS patterns show that the dispersed nano-CuCr_(2)O_(4)advanced the thermal decomposition process of ultrafine AP by about 700 s,especially in the high temperature decomposition stage,and the more concentrated energy release characteristic is beneficial to further enhance the energy performance of AP-based *** above conclusions show that the evaluation method of dispersity based on solid UV curves could pro

关键词： Nano-CuCr_(2)O_(4) Ultrafine AP Dispersity UVeVis diffuse reflectance spectroscopy Thermal decomposition

Structure design of lead-free chiral-polar perovskites for sensitive self-powered X-ray detection

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Chinese Journal of Structural Chemistry 2024年第6期43卷 34-39页

作者： xin Dong Tianqi Chen Jing Liang Lei Wang Huajie Wu Zhijin Xu Junhua luo Li-Na Li State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou350002China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou350108China University of the Chinese Academy of Sciences Beijing100039China

Metal halide perovskites have made significant progress in X-ray detection owing to their exceptional optoelec-tronic ***,most of these materials suffer from toxic element lead and require for high operating ***,it is imperative to explore environmentally friendly perovskite crystals without external bias for X-ray ***,we strategically introduce chiral cations to synthesize a pair of lead-free chiral-polar hybrid perovskites(S-MPz)_(6)Bi_(3)I_(21)·6H_(2)O and(R-MPz)_(6)Bi_(3)I_(21)·6H_(2)O(1S and 1R,S/R-MPz=S/R-2-methylpipera-zinium),which exhibit strong circular dichroism(CD)signals with an anisotropic g-factor reaching approximately ***,the chiral-polar feature gives rise to distinctive spontaneous polarization,which leads to a photovoltage of 1.1 V under X-ray illumination,endowing self-powered detection capabilities for *** exploration of X-ray devices based on 1R single crystal(SC)demonstrates a high sensitivity of 5.2 pC Gy_(air)^(-1)cm^(-2)at zero *** study realizes passive X-ray detection depending on the intrinsic spontaneous polarization induced built-in electric field of chiral-polar perovskite,providing an effective approach to the chemical design of desired materials for high-performance"green"self-powered radiation detection.

关键词： Lead-free perovskite Self-powered Chiral-polar X-ray detection