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Observation and verification of surface electrical explosion driven by radial-distributed pulsed current in laboratory lightning strike test

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High Voltage 2024年第1期9卷 137-149页

作者： Ruoyu Han Yuchen Cao Yakun liu Xi chen Ting li chen li Pengfei li State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijingChina School of Mechatronical Engineering Beijing Institute of TechnologyBeijingChina Department of Electrical Engineering Shanghai Jiaotong UniversityShanghaiChina Beijing Institute of Astronautical System Engineering BeijingChina Aerospace Research Institute of Materials and Processing Technology BeijingChina

The laboratory lightning test is essential for assessing the effectiveness of lightning strike protection(LSP).Particularly,direct lightning strike damage can be performed with pulsed current injection into the specimen.This paper focuses on the dynamic process of arc plasma and shock wave behaviour in the vicinity of the‘strike’point.A rod-plate discharge load is built for testing aluminium and coated plate under 40-kA-level pulsed current.The visualisation of the luminous discharge plasma and its flow field via high-speed photography(from different angles)is meticulously designed and implemented,synchronised with electro-physical diagnostics.The results indicate some new mechanisms for lightning strike damage,apart from the impulse heat loading from the thermal arc.The transient current injection through the arc root concentrates on a thin skin layer(skin-depth effect),with the radial-attenuated current density,driving asynchronously electrical explosions on the plate surface.The inhomogeneous Joule heating of the plate leads to outwardly propagating phase transition and shock wave along the conductive surface.In addition,the electro-thermal instability is observed and regarded as the seed of irregular erosion region.Spectroscopic information reveals two different plasma states of main discharge arc channel and adjacent surface electrical explosion.The correspondence of the physical mechanism of electrical explosion and optical radiation is established.Microscopic images for different regions depict erosion characteristics and summarise influencing factors,further confirming the mechanism above.The research clarifies the role of skin-depth effect in transaction arc erosion for electrode,complements the electrical explosion theory with unevenly distributed current and helps optimise strategies of LSP.

关键词： electrical lightning radial

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Metallurgical performance evaluation of space-weathered Chang’e-5 lunar soil

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1241-1248页

作者： chen li Wenhui Ma Yang li Kuixian Wei Center for Lunar and Planetary Sciences Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming 650093China

Space metallurgy is an interdisciplinary field that combines planetary space science and metallurgical engineering.It involves systematic and theoretical engineering technology for utilizing planetary resources in situ.However,space metallurgy on the Moon is challenging because the lunar surface has experienced space weathering due to the lack of atmosphere and magnetic field,making the mi-crostructure of lunar soil differ from that of minerals on the Earth.In this study,scanning electron microscopy and transmission electron microscopy analyses were performed on Chang’e-5 powder lunar soil samples.The microstructural characteristics of the lunar soil may drastically change its metallurgical performance.The main special structure of lunar soil minerals include the nanophase iron formed by the impact of micrometeorites,the amorphous layer caused by solar wind injection,and radiation tracks modified by high-energy particle rays inside mineral crystals.The nanophase iron presents a wide distribution,which may have a great impact on the electromagnetic prop-erties of lunar soil.Hydrogen ions injected by solar wind may promote the hydrogen reduction process.The widely distributed amorph-ous layer and impact glass can promote the melting and diffusion process of lunar soil.Therefore,although high-energy events on the lun-ar surface transform the lunar soil,they also increase the chemical activity of the lunar soil.This is a property that earth samples and tradi-tional simulated lunar soil lack.The application of space metallurgy requires comprehensive consideration of the unique physical and chemical properties of lunar soil.

关键词： space metallurgy Chang’e-5 lunar soil space weathering metallurgical performance

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Polyethylenimine-modified graphene quantum dots promote endothelial cell proliferation

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Regenerative Biomaterials 2024年第2期3卷 137-146页

作者： Qirong Xu chen li Xiangyan Meng Xinghong Duo Yakai Feng School of Chemistry and Chemical Engineering Qinghai University for NationalitiesXining 810007PR China Key Laboratory of National Ethnic Affairs Commission of Resource Chemistry and Ecological Environment Protection on Qinghai-Tibet Plateau Xining 810007PR China institute of Disaster and Emergency Medicine Tianjin UniversityTianjin 300072PR China School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350PR China Key Laboratory of Systems Bioengineering(Ministry of Education) Tianjin UniversityTianjin 300072PR China

Endothelial cell proliferation plays an important role in angiogenesis and treatment of related diseases.The aim of this study was to evaluate the effect of polyethylenimine(PEI)-modified graphene quantum dots(GQDs)gene vectors on endothelial cell prolifera-tion.The GQDs-cationic polymer gene vectors were synthesized by amidation reaction,and used to deliver pzNF580 gene to Human umbilical vein endothelial cells(HUVECs)for promoting their proliferation.The chemical modification of GQDs can ad-just gene vectors'surface properties and charge distribution,thereby enhancing their interaction with gene molecules,which could effectively compress the pZNF580 gene.The CCK-8 assay showed that the cell viability was higher than 80%at higher vector concentration(40μg/mL),demonstrating that the GQDs-cationic polymer gene vectors and their gene complex nanoparticles(NPs)having low cytotoxicity.The results of the live/dead cell double staining assay were consistent with those of the CCK-8 assay,in which the cell viability of the A-GQDs/pZNF580(94.38±6.39%),C-GQDs-PEI-polylactic acid-co-polyacetic acid(PLGA)/pZNF580(98.65±6.60%)and N-GQDs-PEI-PLGA/pZNF580(90.08±1.60%)groups was significantly higher than that of the lipofectamine 2000/pzNF580(71.98±3.53%)positive treatment group.The results of transfection and western blot experiments showed that the vector significantly enhanced the delivery of plasmid to HUVECs and increased the expression of pZNF580 in HUVECs.In addition,the gene NPs better promote endothelial cell migration and proliferation.The cell migration rate and proliferation ability of C-GQDs-PEI-PLGA/pZNF580 and N-GQDs-PEI-PLGA/pZNF580 treatment groupS were higher than those of lipofectamine 2000/pDNA treatment group.Modified GQDs possess the potential to serve as efficient gene carriers.They tightly bind gene molecules through charge and other non-covalent interactions,significantly improving the effciency of gene delivery and ensuring the smooth release of genes within the cell.This innovative strategy provides a

关键词： graphene quantum dots polyethylenimine ZNF580 gene endothelial cell proliferation

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Adverse effects of exposure to fine particles and ultrafine particles in the environment on different organs of organisms

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Journal of Environmental Sciences 2024年第1期135卷 449-473页

作者： Jianwei Zhang Zhao chen Dan Shan Yang Wu Yue Zhao chen li Yue Shu Xiaoyu linghu Baiqi Wang Department of Occupational and Environmental Health School of Public HealthTianjin Medical UniversityTianjin 300070China Department of Medical Tianjin Stomatological HospitalSchool of MedicineNankai UniversityTianjin 300041China Tianjin Key Laboratory of Environment Nutrition and Public HealthTianjin 300070China National Demonstration Center for Experimental Preventive Medicine Education(Tianjin Medical University) Tianjin 300070China

Particulate pollution is a global risk factor that seriously threatens human health.Fine particles(FPs)and ultrafine particles(UFPs)have small particle diameters and large specific surface areas,which can easily adsorb metals,microorganisms and other pollutants.FPs and UFPs can enter the human body in multiple ways and can be easily and quickly absorbed by the cells,tissues and organs.In the body,the particles can induce oxidative stress,inflammatory response and apoptosis,furthermore causing great adverse effects.Epidemiological studies mainly take the population as the research object to study the distribution of diseases and health conditions in a specific population and to focus on the identification of influencing factors.However,the mechanism by which a substance harms the health of organisms is mainly demonstrated through toxicological studies.Combining epidemiological studies with toxicological studies will provide a more systematic and comprehensive understanding of the impact of PM on the health of organisms.In this review,the sources,compositions,and morphologies of FPs and UFPs are briefly introduced in the first part.The effects and action mechanisms of exposure to FPs and UFPs on the heart,lungs,brain,liver,spleen,kidneys,pancreas,gastrointestinal tract,joints and reproductive system are systematically summarized.In addition,challenges are further pointed out at the end of the paper.This work provides useful theoretical guidance and a strong experimental foundation for investigating and preventing the adverse effects of FPs and UFPs on human health.

关键词： Fine particles Ultrafine particles Organs Adverse effect

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Photoredox-catalyzed C-glycosylation of peptides with glycosyl bromides

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Chinese Chemical Letters 2024年第6期35卷 263-267页

作者： chen li Ziyuan Zhao Shouyun Yu State Key Laboratory of Analytical Chemistry for life Science Jiangsu Key Laboratory of Advanced Organic MaterialsChemistry and Biomedicine Innovation Center(ChemBIC)School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

Glycosyl radicals,produced under mild photoredox conditions,show unique utility in the preparation of C-linked glycoconjugates.We herein report the construction of C-glycosidic bonds on α,β-dehydroalanine(DHA)of peptides with easily available glycosyl bromides as glycosyl radical precursors under highly anomeric control,leading to C-glycosylation modifications of peptides.This method not only has outstanding functional group compatibility,but also is feasible in near-physiological conditions(pH~7 and temperature T≤37℃ in aqueous media).

关键词： Glycosylation C-Glycosides Glycopeptides Dehydroalanine Photoredox catalysis

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A novel predictor of unsustained return of spontaneous circulation in cardiac arrest patients through a combination of capnography and pulse oximetry: a multicenter observational study

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World Journal of Emergency Medicine 2024年第1期15卷 16-22页

作者： Jing Yang Hanqi Tang Shihuan Shao Feng Xu Yangyang Fu Shengyong Xu chen li Yan li Yang liu Joseph Harold Walline Huadong Zhu Yuguo chen Xuezhong Yu Jun Xu Emergency Department State Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College HospitalChinese Academy of Medical Science and Peking Union Medical CollegeBeijing 100730China Emergency Department Peking University People’s HospitalBeijing 100044China Department of Emergency and Chest Pain Center Shandong Provincial Clinical Research Center for Emergency and Critical Care MedicineKey Laboratory of Emergency and Critical Care Medicine of Shandong ProvinceQilu Hospital of Shandong UniversityJinan 250012China Emergency Department Beijing Jishuitan HospitalBeijing 100035China Emergency Department Tianjin Medical University General HospitalTianjin 300052China Department of Emergency Medicine Penn State Health Milton S.Hershey Medical Center and Penn State College of MedicineHershey 17033USA

BACKGROUND:Unsustained return of spontaneous circulation(ROSC)is a critical barrier to survival in cardiac arrest patients.This study examined whether end-tidal carbon dioxide(ETCO_(2))and pulse oximetry photoplethysmogram(POP)parameters can be used to identify unsustained ROSC.METHODS:We conducted a multicenter observational prospective cohort study of consecutive patients with cardiac arrest from 2013 to 2014.Patients’general information,ETCO_(2),and POP parameters were collected and statistically analyzed.RESULTS:The included 105 ROSC episodes(from 80 cardiac arrest patients)comprised 51 sustained ROSC episodes and 54 unsustained ROSC episodes.The 24-hour survival rate was significantly higher in the sustained ROSC group than in the unsustained ROSC group(29.2%vs.9.4%,P<0.05).The logistic regression analysis showed that the difference between after and before ROSC in ETCO_(2)(ΔETCO_(2))and the difference between after and before ROCS in area under the curve of POP(ΔAUCp)were independently associated with sustained ROSC(odds ratio[OR]=0.931,95%confi dence interval[95%CI]0.881-0.984,P=0.011 and OR=0.998,95%CI 0.997-0.999,P<0.001).The area under the receiver operating characteristic curve ofΔETCO_(2),ΔAUCp,and the combination of both to predict unsustained ROSC were 0.752(95%CI 0.660-0.844),0.883(95%CI 0.818-0.948),and 0.902(95%CI 0.842-0.962),respectively.CONCLUSION:Patients with unsustained ROSC have a poor prognosis.The combination ofΔETCO_(2) andΔAUCp showed signifi cant predictive value for unsustained ROSC.

关键词： Return of spontaneous circulation Pulse oximetry photoplethysmogram End-tidal carbon dioxide Cardiac arrest Cardiopulmonary resuscitation

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Atomically dispersed Ni electrocatalyst for superior urea-assisted water splitting

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Journal of Energy Chemistry 2024年第3期90卷 1-6,I0002页

作者： Fang Luo Shuyuan Pan Yuhua Xie chen li Yingjie Yu Zehui Yang College of Materials Science and Engineering State Key Laboratory of New Textile Materials&Advanced Processing TechnologyWuhan Textile UniversityWuhan 430200China Hubei Hydrogen Energy Technology Innovation Center Faculty of Materials Science and ChemistryChina University of GeosciencesWuhan 430074HubeiChina

Urea oxidation reaction(UOR) has been selected as substitution for oxygen evolution reaction ascribing to its low thermodynamic voltage as well as utilization of nickel as electrocatalyst.Herein,we report the formation of nickel single atoms(Ni-SAs) as exceptional bifunctional electrocatalyst toward UOR and hydrogen evolution reaction(HER) in urea-assisted water splitting.In UOR catalysis,Ni-SAs perform a superior catalytic performance than Ni-NP/NC and Pt/C ascribing to the formation of HOO-Ni-N_(4) structure evidenced by in-situ Raman spectroscopy,corresponding to a boosted mass activity by 175-fold at 1.4 V vs.RHE than Ni-NP/NC.Furthermore,Ni-SAs requires only 450 mV overpotential to obtain HER current density of 500 mA cm^(-2).136 mA cm^(-2) is achieved in urea-assisted water splitting at1.7 V for Ni-SAs,boosted by 5.7 times than Pt/C-IrO_(2) driven water splitting.

关键词： Urea oxidation reaction Hydrogen evolution reaction Nickel single atoms Water splitting

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Ripple Knowledge Graph Convolutional Networks for Recommendation Systems

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Machine Intelligence Research 2024年第3期21卷 481-494页

作者： chen li Yang Cao Ye Zhu Debo cheng chengyuan li Yasuhiko Morimoto Graduate School of Informatics Nagoya UniversityChikusaNagoya 464-8602Japan Centre for Cyber Resilience and Trust Deakin UniversityBurwood 3125Australia Science TechnologyEngineering and Mathematics(STEM)University of South AustraliaAdelaide 5000Australia Graduate School of Engineering Hiroshima UniversityHigashi-hiroshima 10587Japan

Using knowledge graphs to assist deep learning models in making recommendation decisions has recently been proven to effectively improve the model′s interpretability and accuracy.This paper introduces an end-to-end deep learning model,named representation-enhanced knowledge graph convolutional networks(RKGCN),which dynamically analyses each user′s preferences and makes a recommendation of suitable items.It combines knowledge graphs on both the item side and user side to enrich their representations to maximize the utilization of the abundant information in knowledge *** is able to offer more personalized and relevant recommendations in three different scenarios.The experimental results show the superior effectiveness of our model over 5 baseline models on three real-world datasets including movies,books,and music.

关键词： Deep learning recommendation systems knowledge graph graph convolutional networks(GCNs) graph neural networks(GNNs).

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A 48-bp deletion upstream of liGULELESS 1 alters rice panicle architecture

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The Crop Journal 2024年第2期12卷 354-363页

作者： linhua Wu Min Hu Shuwei Lyu Wenfeng chen Hang Yu Qing liu Wei He chen li Zuofeng Zhu Rice Research Institute Guangdong Academy of Agricultural SciencesGuangzhou 510640GuangdongChina National Center for Evaluation of Agricultural Wild Plants(Rice) Department of Plant Genetics and BreedingChina Agricultural UniversityBeijing 100193China State Key Laboratory for Rice Biology and Breeding China National Rice Research InstituteHangzhou 310006ZhejiangChina Key Laboratory of Genetics and Breeding of High Quality Rice in Southern China(Co-construction by Ministry and Province) Ministry of Agriculture and Rural AffairsGuangzhou 510640GuangdongChina Guangdong Key Laboratory of New Technology in Rice Breeding Guangzhou 510640GuangdongChina Guangdong Rice Engineering Laboratory Guangzhou 510640GuangdongChina

Panicle architecture is an agronomic determinant of crop yield and a target for cereal crop improvement.To investigate its molecular mechanisms in rice,we performed map-based cloning and characterization of OPEN PANICLE 1(OP1),a gain-of-function allele of liGULELESS 1(LG1),controlling the spread-panicle phenotype.This allele results from a 48-bp deletion in the LG1 upstream region and promotes pulvinus development at the base of the primary branch.Increased OP1 expression and altered panicle phenotype in chimeric transgenic plants and upstream-region knockout mutants indicated that the deletion regulates spread-panicle architecture in the mutant spread panicle 1(sp1).Knocking out BRASSINOSTEROID UPREGULATED1(BU1)gene in the background of OP1 complementary plants resulted in compact panicles,suggesting OP1 may regulate inflorescence architecture via the brassinosteroid signaling pathway.We regard that manipulating the upstream regulatory region of OP1 or genes involved in BR signal pathway could be an efficient way to improve rice inflorescence architecture.

关键词： Upstream region Panicle architecture Gene expression BR Rice

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Damage evolution and removal behaviors of GaN crystals involved in double-grits grinding

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International Journal of Extreme Manufacturing 2024年第2期6卷 469-484页

作者： chen li Yuxiu Hu Zongze Wei Chongjun Wu Yunfeng Peng Feihu Zhang Yanquan Geng State Key Laboratory of Robotics and System(HIT) Harbin Institute of TechnologyHarbin 150001People’s Republic of China Key Laboratory of Microsystems and Microstructures Manufacturing(HIT) Harbin Institute of TechnologyHarbin 150001People’s Republic of China College of Mechanical Engineering Donghua UniversityShanghai 201620People’s Republic of China Department of Mechanical and Electrical Engineering Xiamen UniversityXiamen 361005People’s Republic of China

Elucidating the complex interactions between the work material and abrasives during grinding of gallium nitride(GaN)single crystals is an active and challenging research area.In this study,molecular dynamics simulations were performed on double-grits interacted grinding of GaN crystals;and the grinding force,coefficient of friction,stress distribution,plastic damage behaviors,and abrasive damage were systematically investigated.The results demonstrated that the interacted distance in both radial and transverse directions achieved better grinding quality than that in only one direction.The grinding force,grinding induced stress,subsurface damage depth,and abrasive wear increase as the transverse interacted distance increases.However,there was no clear correlation between the interaction distance and the number of atoms in the phase transition and dislocation length.Appropriate interacted distances between abrasives can decrease grinding force,coefficient of friction,grinding induced stress,subsurface damage depth,and abrasive wear during the grinding process.The results of grinding tests combined with cross-sectional transmission electron micrographs validated the simulated damage results,i.***.amorphous atoms,high-pressure phase transition,dislocations,stacking faults,and lattice distortions.The results of this study will deepen our understanding of damage accumulation and material removal resulting from coupling between abrasives during grinding and can be used to develop a feasible approach to the wheel design of ordered abrasives.

关键词： grinding double-grits molecular dynamics damage material removal gallium nitride

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