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Stable,intense supercontinuum light generation at 1 kHz by electric field assisted femtosecond laser filamentation in air

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Light(Science & Applications) 2024年第2期13卷 354-365页

作者： Yaoxiang liu Fukang Yin tie-Jun Wang Yuxin Leng Ruxin Li Zhizhan Xu See Leang Chin State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine Mechanics and CAS Center for Excellence in Ultra-intense Laser ScienceChinese Academy of SciencesShanghaiChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijingChina Centre d’Optique Photonique et Laser(COPL)and Département de physiquede génie physique et d’optiqueUniversitéLavalQuébecQuébecCanada

Supercontinuum(SC)light source has advanced ultrafast laser spectroscopy in condensed matter science,biology,physics,and chemistry.Compared to the frequently used photonic crystal fibers and bulk materials,femtosecond laser filamentation in gases is damage-immune for supercontinuum generation.A bottleneck problem is the strong jitters from filament induced self-heating at kHz repetition rate level.We demonstrated stable kHz supercontinuum generation directly in air with multiple mJ level pulse energy.This was achieved by applying an external DC electric field to the air plasma filament.Beam pointing jitters of the 1 kHz air filament induced SC light were reduced by more than 2 fold.The stabilized high repetition rate laser filament offers the opportunity for stable intense SC generation and its applications in air.

关键词： intense repetition light

Exploration of cardiac rehabilitation nursing for elderly patients with myocardial infarction based on individualized cardiac rehabilitation

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World Journal of Clinical Cases 2024年第2期12卷 256-266页

作者： Hua-ning liu Bo Gao Department of Geriatrics General Hospital of the YangTze River ShippingWuhan Brain HospitalWuhan 430015Hubei ProvinceChina Department of Cardiology Suizhou Central HospitalAffiliated Hospital of Hubei University of MedicineSuizhou 441300Hubei ProvinceChina

BACKGROUND Myocardial infarction is a high-risk condition prevalent among the elderly population,often leading to adverse clinical manifestations such as reduced cardiopulmonary function,anxiety,and depression post-surgery.Consequently,cardiac rehabilitation holds immense importance in mitigating these complications.AIM To evaluate the effect of individualized cardiac rehabilitation on blood pressure variability(BPV)and baroreflex sensitivity(BRS)in elderly patients with myocardial infarction.METHODS A cohort of 74 elderly patients diagnosed with myocardial infarction and admitted to our hospital between January 2021 and January 2022 were subjected to random selection.Subsequently,all patients were divided into two groups,namely the research group(n=37)and the control group(n=37),utilizing the number table method.The control group received conventional drug treatment and nursing guidance intervention,while the study group underwent individualized cardiac rehabilitation in addition to the interventions received by the control group.All patients were continuously intervened for 12 wk,and the BPV of these two groups in the 1st wk(T0),the 4th wk(T1)and the 12th wk(T2)were compared,BRS,changes in cardiopulmonary function measures,and adverse cardiovascular events.RESULTS Of 24 h diastolic BPV,24 h systolic BPV,carbon dioxide ventilation equivalent slope of the research group were lower than those of the control group at T1 and T2,BRS,peak heart rate and systolic blood pressure product,1 min heart rate recovery were higher than those of the control group,and the incidence of adverse events in the research group was lower than that of the control group,the difference was statistically significant(Ptients with myocardial infarction,BPV and BRS can be effectively improved,cardiac function is significantly enhanced,and a better prognosis is obtained.

关键词： Individualized cardiac rehabilitation Myocardial infarction Variability in blood pressure Baroreflex sensitivity

Pushing the frontiers: Chip-based detection based on micro-and nano-structures

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Chinese Chemical Letters 2024年第4期35卷 86-98页

作者： Meihui liu Xinyuan Zhou Xiao Li Zhenjie Xue tie Wang Tianjin Key Laboratory of Life and Health Detection Life and Health Intelligent Research InstituteTianjin University of TechnologyTianjin 300384China

Changes in trace substances in human metabolites, which are related to disease processes and health status, can serve as chemical markers for disease diagnosis and symptom monitoring. Real-time online detection is an inevitable trend for the future of health monitoring, and the construction of chips for detection faces major challenges. The response of sensors often fails to meet the requirements for chipbased detection of trace substances due to the low efficiency of interfacial heterogeneous reactions, necessitating a rational design approach for micro-and nano-structures to improve sensor performance with respect to sensitivity and detection limits. This review focuses on the influence of micro-and nanostructures that used in chip on sensing. Firstly, this review categorizes sensors into chemiresistors, electrochemical sensors, fluorescence sensors, and surface enhanced Raman scattering(SERS) sensors based on their sensing principle, which have significant applications in disease diagnosis. Subsequently, commencing from the application requirements in the field of sensing, this review focuses on the different structures of nanoparticle(NP) assemblies, including wire, layered, core-shell, hollow, concave and deformable structures. These structures change in the size, shape, and morphology of conventional structures to achieve characteristics such as ordered alignment, high specific surface area, space limitation,vertical diffusion, and swaying behavior with fluid, thereby addressing issues such as poor signal transmission efficiency, inadequate adsorption and capture capacity, and slow mass transfer speed during sensing. Finally, the design direction of micro-and nano-structures, and possible obstacles and solutions to promote chip-based detection have been discussed. It is hope that this article will inspire the exploration of interface micro-and nano-structures modulated sensing methods.

关键词： Chip-based detection Micro-and nano-structures Real-time online detection Sensing Health monitoring

PPB structure elimination,DRX nucleation mechanisms and grain growth behavior of the3rd-generation PM superalloy for manufacturing aviation components

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Chinese Journal of Aeronautics 2024年第1期37卷 325-344页

作者： Baoyun ZHANG Yongquan ning Zhaotian WANG Qiaomu liu School of Materials Science and Engineering Northwestern Polytechnical UniversityXi’an 710072China AECC Sichuan Gas Turbine Establishment Chengdu 610500China

Previous Particle Boundary(PPB),as the detrimental structure in Powder Metallurgy(PM)components,should be eliminated by subsequent hot process to improve the mechanical properties.The objective is to investigate the Dynamic Recrystallization(DRX)nucleation mechanisms and grain growth behavior of the 3rd-generation PM superalloy with PPB structure.Microstructure observation reveals that PPB decorated with(Ti,Ta,Nb)C carbides belongs to the discontinuous chain-like structure.The elimination of PPB networks can be achieved effectively via hot deformation due to the occurrence of DRX.Four different DRX nucleation mechanisms were proposed and discussed in detail according to the special microstructure characteristics of the PM superalloy.Firstly,local lattice rotations can be detected in the vicinity of(Ti,Ta,Nb)C carbides during hot deformation and thus PPB structure serves as the preferential nucleation sites for DRX grains via Particle-Stimulated Nucleation(PSN).Then,Discontinuous-DRX(DDRX)characterized by grain boundary bulging dominates the microstructure refinement and Continuous-DRX(CDRX)operated by subgrain rotation can be regarded as an important assistant mechanism.At last,the initial Σ3 boundaries would lose their twin characteristics owing to the crystal rotation and then transform into the general High Angle Grain Boundaries(HAGBs).The distorted twins provide additional DRX nucleation sites,viz.,twin-assisted nucleation.Particular attention was focused on the grain growth behavior of the PM superalloy in subsequent annealing process.The recrystallization temperature was determined to be about 1110.C and 1140.C can be considered as the critical temperature for grain growth.The findings would provide theoretical support for microstructure refinement of the 3rd-generation PM superalloy,which is of pivotal significance for improving the mechanical properties of aviation components.

关键词： PM superalloy Previous Particle Boundary(PPB) DRX nucleation Grain growth Microstructure refinement

Nickel-Catalyzed Regiodivergent Acylzincation of Styrenes with Organozincs and CO

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Chinese Journal of Chemistry 2024年第6期42卷 599-604页

作者： Chenglong Wang ning liu Xianqing Wu Jingping Qu Yifeng Chen Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research CenterFrontiers Science Center for Materiobiology and Dynamic ChemistrySchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai200237 China Dedicated to the Special Issue of C1 Chemistry.

Transition metal-catalyzed carbometallation of unsaturated hydrocarbons constitutes one of the most efficient synthetic methodologies for the construction of C—C bond.Recently,the incorporation of organometallic reagent with the CO gas as a nucleophilic acyl synthon could enable the acylmetallation reaction,which greatly increases the horizon of carbometallation chemistry.Herein,we report a nickel-catalyzed regiodivergent acylzincation of o-cyano cinnamate ester and o-cyano styrene,in which the cyano moiety intramolecularly captures zinc intermediates to trigger the tandem cyclization process.This protocol features mild conditions,broad substrate scope and excellent functional group tolerance,thus affording a diverse array of highly functionalized carbocyclic compounds.

关键词： Carbonylation Carbometallation Styrene Nickel Cyclization

{1012}twin–twin intersection-induced lattice rotation and dynamic recrystallization in Mg–6Al–3Sn–2Zn alloy

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Journal of Magnesium and Alloys 2024年第4期12卷 1529-1539页

作者： Bin-Jiang Lv Sen Wang Fu-Hao Gao ning Cui Yi-Nan Li tie-Wei Xu Feng Guo School of Mechanical and Automotive Engineering Qingdao University of Technology266520China Key Lab of industrial Fluid Energy Conservation and Pollution Control Qingdao University of Technology266520China

This study investigated the formation mechanism of new grains due to twin–twin intersections in a coarse-grained Mg–6Al–3Sn–2Zn alloy during different strain rates of an isothermal compression.The results of electron backscattered diffraction investigations showed that the activated twins were primarily{1012}tension twins,and 60°boundaries formed due to twin–twin intersections under different strain rates.Isolated twin variants with 60°boundaries transformed into new grains through lattice rotations at a low strain rate(0.01 s^(−1)).At a high strain rate(10 s^(−1)),the regions surrounded by subgrain boundaries through high-density dislocation arrangement and the 60°boundaries transformed into new grains via dynamic recrystallization.

关键词： Mg alloy Twin-twin intersection Lattice rotation Dynamic recrystallization

Effects of orientation on the fatigue crack growth behaviors of the ZK60 magnesium alloy in air and PBS

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Journal of Magnesium and Alloys 2024年第1期12卷 281-294页

作者： Jiaqi Hu Zheng liu Zuoliang ning Hong Gao School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China Tianjin Key Laboratory of Chemical Process Safety and Equipment Technology Tianjin 300072China

Strong anisotropic corrosion and mechanical properties caused by specimen orientations greatly limit the applications of wrought magnesium alloys.To investigate the influences of specimen orientation,the corrosion tests and(corrosion)fatigue crack growth tests were conducted.The rolled and transverse surfaces of the materials show distinct corrosion rate differences in the stable corrosion stage,but the truth is the opposite for the initial stage of corrosion.In air,specimen orientations have a significant influence on the plastic deformation mechanisms near the crack tip,which results in different fatigue fracture surfaces and cracking paths.Compared with R-T specimens,N-T specimens show a slower fatigue crack growth(FCG)rate in air,which can be attributed to crack closure effects and deformation twinning near the crack tip.The corrosion environment will not significantly change the main plastic deformation mechanisms for the same type of specimen.However,the FCG rate in phosphate buffer saline(PBS)is one order of magnitude higher than that in air,which is caused by the combined effects of hydrogen-induced cracking and anodic dissolution.Owing to the similar corrosion rates at crack tips,the specimens with different orientations display close FCG rates in PBS.

关键词： Magnesium alloy Orientation Corrosion Fatigue crack growth

Fundamental Understanding of Hydrogen Evolution Reaction on Zinc Anode Surface:A First‑Principles Study

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Nano-Micro Letters 2024年第6期16卷 180-191页

作者： Xiaoyu liu Yiming Guo Fanghua ning Yuyu liu Siqi Shi Qian Li Jiujun Zhang Shigang Lu Jin Yi Institute for Sustainable Energy&Department of Chemistry Shanghai UniversityShanghai 200444People’s Republic of China School of Materials Science and Engineering Shanghai UniversityShanghai 200444People’s Republic of China College of Materials Science and Engineering National Engineering Research Center for Magnesium AlloysChongqing UniversityChongqing 400044People’s Republic of China

Hydrogen evolution reaction(HER)has become a key factor affecting the cycling stability of aqueous Zn-ion batteries,while the corresponding fundamental issues involving HER are still unclear.Herein,the reaction mechanisms of HER on various crystalline surfaces have been investigated by first-principle calculations based on density functional theory.It is found that the Volmer step is the ratelimiting step of HER on the Zn(002)and(100)surfaces,while,the reaction rates of HER on the Zn(101),(102)and(103)surfaces are determined by the Tafel step.Moreover,the correlation between HER activity and the generalized coordination number(CN)of Zn at the surfaces has been revealed.The relatively weaker HER activity on Zn(002)surface can be attributed to the higher CN of surface Zn atom.The atomically uneven Zn(002)surface shows significantly higher HER activity than the flat Zn(002)surface as the CN of the surface Zn atom is lowered.The CN of surface Zn atom is proposed as a key descriptor of HER activity.Tuning the CN of surface Zn atom would be a vital strategy to inhibit HER on the Zn anode surface based on the presented theoretical studies.Furthermore,this work provides a theoretical basis for the in-depth understanding of HER on the Zn surface.

关键词： Aqueous Zn-ion battery Zn anode Hydrogen evolution reaction Coordination number First-principles calculation

Synthesis of covalent organic framework materials and their application in the field of sensing

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Nano Research 2024年第1期17卷 162-195页

作者： Weiyu Zhang Shiwei liu Qihua Sun ning Tian Zhaofeng Wu Xinjiang Key Laboratory of Solid-State Physics and Devices Urumqi 830046China School of Physics Science and Technology Xinjiang UniversityUrumqi 830046China

Covalent organic frameworks(COFs)are an emerging type of porous crystalline polymers formed by combining strong covalent bonds with organic building blocks.Due to their large surface area,high intrinsic pore space,good crystallization properties,high stability,and designability of the resultant units,COFs are widely studied and used in the fields of gas adsorption,drug transport,energy storage,photoelectric catalysis,electrochemistry,and sensors.In recent years,the rapid development of the Internet of Things and people’s yearning for a better life have put forward higher and more requirements for sensors,which are the core components of the Internet of Things.Therefore,this paper reviews the recent progress of COFs in synthesis methods and sensing applications,especially in the last five years.This paper first introduces structure,properties,and synthesis methods of COFs and discusses advantages and disadvantages of different synthesis methods.Then,the research progress of COFs in different sensing fields,such as metal ion sensors,gas sensors,biomedical sensors,humidity sensors,and pH sensors,is introduced systematically.Conclusions and prospects are also presented in order to provide a reference for researchers concerned with COFs and sensors.

关键词： covalent organic framework materials structural design and synthesis sensing application gas sensors