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Mn-modified nitrogen-doped Pt-based electrocatalyst for efficient oxygen reduction in aluminum-air batteries

Nano Research 2024年第8期17卷 7126-7135页

作者： li Gao yang Song Xuebing Xu Chang li Chaoquan Hu State Key Laboratory of Mesoscience and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China Zhongke Nanjing Institute of Green Manufacturing Industry Nanjing 211135China

In this study,a Mn-modified Pt-based catalyst loaded on nitrogen-doped Ketjen black(Mn-Pt/NKB)is prepared using a simple ethylene glycol reduction *** size of Pt nanoparticles(NPs)is effectively controlled by doping with Mn and *** the smallest average particle size of 1.7 nm,Mn-Pt/NKB demonstrates half-wave potentials of 0.890 and 0.688 V in the alkaline and neutral electrolytes,respectively,which are superior to those of commercial platinum on activated carbon(Pt/C).When applied as an air cathode in aluminum-air battery,it exhibits ultra-high power densities of 190(alkaline)and 26.2 mW·cm^(−2)(neutral).Moreover,the voltage remains stable after 5 h of *** practical application performance of the Mn-Pt/NKB catalyst in an aluminum-air battery is better than that of commercial Pt/***,the oxygen reduction reaction(ORR)mechanism on surfaces with different particle sizes is analyzed using density functional *** cracking is the major pathway on the surface of the small particles with lower energy consumption of 0.5 eV,while water molecule cleavage is the major pathway on the surface of the large particles with higher energy consumption of 0.97 *** lower energy consumption of the oxygen cracking pathway further confirms the ORR mechanism for higher activity on small-sized *** study provides a direction for the rational design of Pt-based catalysts for ORR and sheds light on the commercial development of aluminum-air batteries.

关键词： oxygen reduction reaction precious metal catalysts aluminum-air battery density functional theory(DFT)calculations reaction pathway

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Cerium oxide inclusion nucleation mechanism based on classical nucleation theory and two-step nucleation

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Journal of Rare Earths 2024年第4期42卷 793-802页

作者： Yutang li Jun Wang linzhu Wang Chaoyi Chen Shufeng yang Junqi li Xiang li School of Materials and Metallurgy Guizhou UniversityGuiyang550025China State Key Laboratory of Public Big Data Guizhou UniversityGuiyang550025China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Department of Materials&Metallurgy Engineering Guizhou Institute of TechnologyGuiyang550003China

It is challenging to assess the mechanism responsible for the nucleation of inclusions in metals at high *** present work therefore systematically investigates the nucleation of cerium oxide inclusions according to classical nucleation theory and a two-step nucleation *** nucleation rates and nucleation radii of these inclusions are obtained,and the results demonstrate a considerable difference between theoretical and experimental *** the basis of a two-step nucleation mechanism,(CeO_(2))_(n) and(Ce_(2)O_(3))_(n)(n=1-6)clusters were constructed and the thermodynamic properties of both these clusters and of cerium oxide nanoparticles were *** addition,the entropies and heat capacity changes of cerium oxides were determined using first principles calculations and are found to be consistent with literature *** present data indicate that the cerium oxide inclusion nucleation pathway can be summarized as[Ce]+[O]→(CeO_(2))n/(Ce_(2)O_(3))_(n)→(Ce_(2)O_(3))_(n)→(Ce_(2)O_(3))_(2)→core(Ce_(2)O_(3)crystal)-shell((Ce_(2)O_(3))_(2) cluster)nanoparticles→(Ce_(2)O_(3))bulk.

关键词： Cerium oxide inclusion Classical nucleation theory Two-step nucleation mechanism First principles Rare earths

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Source apportionment of PM_(2.5)using PMF combined online bulk and single-particle measurements:Contribution of fireworks and biomass burning

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Journal of Environmental Sciences 2024年第2期136卷 325-336页

作者： Yanjing Zhang Wenshuai li Lei li Mei li Zhen Zhou Jianzhen Yu yang Zhou Frontier Science Center for Deep Ocean Multispheres and Earth System(FDOMES)and Physical Oceanography Laboratory Ocean University of ChinaQingdaoShandong 266100China College of Oceanic and Atmospheric Sciences Ocean University of ChinaQingdaoShandong 266100China Institute of Atmospheric Environment Safety and Pollution Control Jinan UniversityGuangdong 510632China Institute of Environment Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina Department of Chemistry Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina Division of Environment The Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina

Fireworks(FW)could significantly worsen air quality in short term during *** to similar tracers with biomass burning(BB),the fast and precise qualification of FW and BB is still *** this study,online bulk and single-particle measurements were combined to investigate the contributions of FW and BB to the overall mass concentrations of PM_(2.5)and specific chemical species by positive matrix factorization(PMF)during the Chinese New Year in Hong Kong in February *** combined information,fresh/aged FW(abundant ^(140)K_(2)NO_(3)^(+)and ^(213)K_(3)SO_(4)^(+)formed from ^(113)K_(2)Cl^(+)discharged by fresh FW)can be extracted from the fresh/aged BB sources,in addition to the Second Aerosol,Vehicles+Road Dust,and Sea Salt *** contributions of FW and BB were investigated during three high particle matter episodes influenced by the pollution transported from the Pearl River Delta *** fresh BB/FW contributed 39.2%and 19.6%to PM_(2.5)during the Lunar Chinese New Year ***,the contributions of aged FW/BB enhanced in the last two episodes due to the aging process,evidenced by high contributions from secondary ***,the fresh BB/FW showed more significant contributions to nitrate(35.1%and15.0%,respectively)compared with sulfate(25.1%and 5.9%,respectively)and OC(14.8%and11.1%,respectively)on *** comparison,the aged FW contributed more to sulfate(13.4%).Overall,combining online bulk and single-particle measurement data can combine both instruments’advantages and provide a new perspective for applying source apportionment of aerosols using PMF.

关键词： Source apportionment PMF Online bulk measurements Single particle analysis Fireworks Biomass burning

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Effect of droplet characteristics on liquid-phase distribution in spray zone of internal mixing air-mist nozzle

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China Foundry 2024年第2期21卷 185-196页

作者： Wei-li Wu Chang-gui Cheng yang li Shi-fa Wei De-li Chen The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081China Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081China Technology Center Fushun Special Steel Co.Ltd.Fushun 113001LiaoningChina

In continuous casting production,droplet characteristics are important parameters for evaluating the nozzle atomization quality,and have a significant impact on the secondary cooling effect and the slab *** order to study the behavior of atomized droplets after reaching the slab surface and to optimize the spray cooling effect,the influence of droplet diameter and droplet velocity on the migration behavior of droplets in the secondary cooling zone was analyzed by FLUENT *** show that the droplets in the spray zone and on the slab surface are mainly concentrated in the center,thus,the liquid volume fraction in the center is higher than that of either *** the droplet diameter increases,the region of high liquid volume fraction on the slab surface becomes wider,and the liquid phase distribution in the slab width direction becomes *** increasing the droplet velocity at the nozzle exit has little effect on droplet diffusion in the spray zone,the distribution becomes more uneven due to more liquid reaches the slab surface per unit time.A prediction formula of the maximum water flow rate on the slab surface for specific droplet characteristics was proposed based on dimensionless analysis and validated by simulated data.A nozzle spacing of 210 mm was recommended under the working conditions in this study,which ensures effective coverage of the spray water over the slab surface and enhances the distribution uniformity of water flow rate in the transverse direction.

关键词： continuous casting secondary cooling zone internal mixing air-mist nozzle droplet characteristics liquid phase distribution water flow rate

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Identification of candidate biomarkers correlated with pathogenesis of postoperative peritoneal adhesion by using microarray analysis

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World Journal of Gastrointestinal Oncology 2020年第1期12卷 54-65页

作者： Yao-Yao Bian li-li yang Yan Yan Min Zhao Yan-Qi Chen Ya-Qi Zhou Zi-Xin Wang Wen-lin li li Zeng School of Nursing Nanjing University of Chinese MedicineNanjing 210023Jiangsu ProvinceChina School of First Clinical Medicine Nanjing University of Chinese MedicineNanjing 210023Jiangsu ProvinceChina Jingwen library Nanjing University of Chinese MedicineNanjing 210023Jiangsu ProvinceChina Guang′anmen Hospital China Academy of Chinese Medical SciencesBeijing 100053China

BACKGROUND Postoperative peritoneal adhesion(PPA),characterized by abdominal pain,female infertility,and even bowel obstruction after surgery,has always been a major *** occurrence and formation of adhesion are from complex biological ***,the molecular mechanisms underlying the basis of microarray data profile,followed by peritoneal adhesion formation,are largely *** To reveal the underlying pathogenesis of PPA at the molecular *** The gene expression profile was retrieved from the Gene Expression Omnibus database for our *** identified a panel of key genes and related pathways involved in adhesion formation using bioinformatics analysis *** performed quantitative PCR and western blotting in vivo to validate the results *** In total,446 expressed genes were altered in peritoneal *** found that several hub genes(e.g.,tumor necrosis factor,interleukin 1 beta,interleukin 6,CX-C motif chemokine ligand 1,C-X-C motif chemokine ligand 2)were marked as significant *** analysis suggested that these genes were enriched in the Toll-like receptor signaling *** to the Kyoto Encyclopedia of Genes and Genomes pathway and published studies,TLR4,myeloid differentiation primary response protein 88(MyD88),and nuclear factor kappa B(NF-κB)played essential roles in Toll-like signaling ***,we obtained a regulatory evidence chain of TLR4/MyD88/NF-κB/inflammatory cytokines/peritoneal adhesion involved in the pathogenesis of postoperative *** results of the microarray analysis were verified by the animal *** findings may extend our understanding of the molecular mechanisms of *** The regulatory evidence chain of TLR4/MyD88/NF-κB/inflammatory cytokines/peritoneal adhesion may play key roles in the pathogenesis of *** studies are required to validate our findings.

关键词： Postoperative peritoneal adhesion Candidate biomarkers Molecular pathogenesis Bioinformatics analysis

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Single-atom catalysis:a promising avenue for precisely controlling reaction pathways

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Frontiers of Chemical Science and Engineering 2024年第7期18卷 97-120页

作者： Xiaobo yang Xuning li Yanqiang Huang State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China

Single-atom catalysts (SACs), characterized by exceptionally high atom efficiency, have garnered significant attention across various catalytic reactions. Recent studies have showcased SACs with robust capabilities for precise catalysis, specifically targeting reactions along designated pathways. This review focuses on the advances in the precise activation and reconstruction of chemical bonds on SACs, including precise activation of C–O and C–H bonds and selective couplings involving C–C and C–N bonds. Our discussion begins with a thorough exploration of the factors that render SACs skilled in precise catalytic processes, encompassing the narrow d-band electronic state of single atom site resulting in the adsorption tendency, isolate site resulting in unique adsorption structure, and synergy effect of a single atom site with its neighbors. Subsequently, we elaborate on the applications of SACs in electrocatalysis and thermocatalysis including four prominent reactions, namely, electrochemical CO_(2) reduction, urea electrochemical synthesis, CO_(2) hydrogenation, and CH4 activation. Then the concept of rational design of SACs for precisely controlling reaction pathways is discussed from the aspects of pore structure design, support-metal strong interaction, and support hydrophilic/hydrophobic. Finally, we summarize the challenges encountered by SACs in the field of precise catalytic processes and outline prospects for their further development in this domain.

关键词： single atom catalysts selective oxidation CO_(2)RR bond coupling

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Modeling wave propagation across rock masses using an enriched 3D numerical manifold method

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Science China(Technological Sciences) 2024年第3期67卷 835-852页

作者： yang YongTao li JunFeng WU WenAn State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China Key Laboratory of Urban Security and Disaster Engineering Ministry of EducationBeijing University of TechnologyBeijing 100124China University of Chinese Academy of Sciences Beijing 100049China

The three-dimensional numerical manifold method(3DNMM) method is further enriched to simulate wave propagation across homogeneous/jointed rock masses. For the purpose of minimizing negative effects from artificial boundaries, a viscous nonreflecting boundary, which can effectively absorb the energy of a wave, is firstly adopted to enrich 3DNMM. Then, to simulate the elastic recovery property of an infinite problem domain, a viscoelastic boundary, which is developed from the viscous nonreflecting boundary, is further adopted to enrich 3DNMM. Finally, to eliminate the noise caused by scattered waves, a force input method which can input the incident wave correctly is incorporated into 3DNMM. Five typical numerical tests on P/S-wave propagation across jointed/homogeneous rock masses are conducted to validate the enriched 3DNMM. Numerical results indicate that wave propagation problems within homogeneous and jointed rock masses can be correctly and reliably modeled with the enriched 3DNMM.

关键词： 3D numerical manifold method viscous nonreflecting boundary rock masses force input method wave propagation

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Room-temperature ferrimagnetism and size-modulated electronic structures in two-dimensional cluster-based metal-organic frameworks

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Science China Chemistry 2024年第4期67卷 1334-1340页

作者： Jing Cheng Xingxing li Jinlong yang Key Laboratory of Precision and Intelligent Chemistry University of Science and Technology of ChinaHefei 230026China Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China Hefei National Research Center for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

Cluster-assembled materials have attracted particular attention for their complex hierarchical structures and unique ***,the majority of cluster-based assemblies developed so far are either non-magnetic or only exhibit magnetic ordering with a relatively low Curie temperature,limiting their applications in ***,two-dimensional(2D)cluster-assembled materials with room-temperature magnetism remain highly *** this purpose,based on first principles calculations,we design a series of thermodynamically stable 2D cluster-based metal-organic frameworks(MOFs)Fe_(n)-(pyz)(n=1-6)by utilizing Fenmetal clusters as nodes and nitrogen-containing pyrazine ligands as organic *** 2D cluster-based MOFs exhibit robust ferrimagnetic ordering due to the strong d-p direct exchange interaction between d-electron spin of Fe_(n)(n=1-6)clusters and charge transfer-induced p-electron spin of pyrazine *** particular,the ferrimagnetic Curie temperatures are well above room temperature(up to 836 K).Additionally,altering the size of Fe_(n)clusters in Fe_(n)-(pyz)(n=1-6)MOFs results in diverse functional spintronic properties,including bipolar magnetic semiconductors,half semiconductors and Dirac half ***,these 2D assembled MOFs possess sizable magnetic anisotropy energies,up to 9.16 me V per formula.

关键词： metal-organic framework two-dimensional material half metal bipolar magnetic semiconductor magnet

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Evaluation of UAV spraying quality based on 1D-CNN model and wireless multi-sensors system

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Information Processing in Agriculture 2024年第1期11卷 65-79页

作者： Ziyuan Hao Minzan li Wei yang Xinze li Key Laboratory of Smart Agriculture Systems Ministry of EducationChina Agricultural UniversityBeijing 100083PR China

The droplet deposition is a key index to evaluate the quality of unmanned aerial vehicle(UAV)*** detection of the droplet deposition is time-consuming and costly,therefore,it is difficult to achieve large-scale and rapid acquisition in the *** solve the above problems,a droplet deposition acquisition system(DDAS)was *** was composed of the multiple sensors,processing units,remote server database and Android-based software.A droplet deposition prediction model based on field experimental data was established by using a one-dimensional convolutional neural network(1D-CNN)algorithm,and the effects of different inputs on the prediction ability of the model were *** results showed that adding temperature and humidity data to the inputs can achieve higher prediction accuracy than only using UAV spraying operation parameters and wind speed data as the inputs to the *** addition,the prediction accuracy of the 1D-CNN model was the highest when compared with other models such as back propagation neural network,multiple correlation vector machine,and multiple linear *** 1D-CNN model was embedded into the DDAS,and the evaluation experiments were carried out in the *** correlation analysis was conducted between two datasets of the droplet deposition obtained by the DDAS and water sensitive paper(WSP),*** R2 was 0.924,and the RMSE was 0.026μL/*** is proved that the droplet deposition values obtained by the DDAS and WSP have high consistency,and the DDAS developed can provide an auxiliary solution for the intelligent evaluation of UAV spraying quality.

关键词： UAV Spraying quality Droplet deposition 1D-CNN model Sensor

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Two-way shape memory effect in a Ti-Zr-Nb-Ta high-temperature shape memory alloy

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Rare Metals 2024年第3期43卷 1257-1262页

作者： Cheng-yang Xiong Tuo li Jun Wang Yan li School of Materials Science and Engineering Beihang UniversityBeijing100191China

The two-way shape memory effect in a Ti-18.5Zr-10Nb-3.5Ta high-temperature shape memory alloy was investigated.X-ray diffraction measurem ent shows that the alloy is composed of orthorhombicα"-martensite.ωphase is not found in Ti-18.5Zr-10Nb-3.5Ta alloy due to the suppressing effect of Ta ***α"-martensite laths are found in the transmission electron microscope observation;after the bending deformation,there appear a lot of *** alloy exhibits a shape memory strain of 3.8%aud a high reverse martensite transformation start temperature of 464 *** maximum two-way shape memory strain of 1.2%is obtained in the alloy with the prebending training strain of 10%.The mechanism can be ascribed to the effect of internal stress field caused by dislocations.

关键词： Ti-Zr Shape memory alloys Two-way shape memory effect

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