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Photonuclear production of nuclear isomers using bremsstrahlung induced by laser-wakefield electrons

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Nuclear Science and Techniques 2023年第5期34卷 112-124页

作者： hao-yang lan Di Wu Jia-Xin Liu Jian-Yao Zhang Huan-Gang Lu Jian-Feng Lv Xue-Zhi Wu Wen Luo Xue-Qing Yan State Key Laboratory of Nuclear Physics and Technology and Key Laboratory of HEDP of the Ministry of EducationCAPTPeking UniversityBeijing 100871China School of Nuclear Science and Technology University of South ChinaHengyang 421001China

In this study,we theoretically investigate the feasibility of using laser-wakefield accelerated(LWFA)electrons for the photonuclear measurement of nuclear isomers according to the characteristics of the electrons obtained from LWFA experiments conducted at the Compact Laser-Plasma Accelerator(CLAPA)*** experiments at the CLAPA show that a stable electron beam with an energy of 78-135 MeV and a charge of 300-600 pC can be *** bremsstrahlung spectra were simulated using Geant4,which suggests that a bremsstrahlung source with a peak intensity of 10^(19) photons/s can be *** calculations of isomer production cross sections from the photonuclear reactions on six target nuclei,^(197)Au,^(180)Hf,^(159)Tb,^(115)In,^(103)Rh,and ^(90)Zr,were performed and compared with the available experimental data in EXFOR,which suggest that further experiments are required for a series of photonuclear reaction ***-averaged cross sections and isomer ratios(IR)resulting from such bremsstrahlung sources are theoretically *** results suggest that IR measurements can be used to constrain nuclear components,such asγstrength function and optical model *** addition,the detection of the decay characteristics was evaluated with Geant4 *** use of the LWFA electron beam and its bremsstrahlung for photonuclear studies involving nuclear isomers is anticipated.

关键词： Photonuclear reactions Laser–plasma acceleration Flux-averaged isomer ratio

Model for estimating the weight-loss ratio of damaged Korla fragrant pears

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International Journal of Agricultural and Biological Engineering 2024年第1期17卷 261-266页

作者： yang Liu Yurong Tang Hong Zhang hao Niu Haipeng lan College of Mechanical and Electrical Engineering Tarim UniversityAlaer 843300XinjiangChina College of Water Resources and Architectural Engineering Tarim UniversityAlaer 843300XinjiangChina

To predict the weight-loss ratio of Korla fragrant pears effectively,improve commodity value and study the variation laws of the weight-loss ratio of damaged fragrant pears during storage,this study predicted the weight-loss ratio of fragrant pears by utilizing the generalized regression neural network(GRNN),support vector regression(SVR),partial least squares regression(PLSR)and error back propagation neural network(BPNN).The prediction performances of GRNN,SVR,PLSR and BPNN models were compared comprehensively,and the optimal model was *** addition,the optimal prediction model was *** results show that weight-loss ratio of fragrant pears increases gradually with the extension of storage *** storage,the weight-loss ratio of fragrant pears is positively related to the degree of *** trained GRNN,SVR,PLSR and BPNN models can be used to predict the weight-loss ratio of fragrant *** BPNN model is the most accurate in predicting the weight-loss ratio of damaged fragrant pears(R^(2)=0.9929;RMSE=0.2138).It has also been proved to have good predictive effect in production practice(R^(2)=0.9377,RMSE=0.7138).The research findings can provide references to predict the delivery quality and time of delivery of Korla fragrant pears.

关键词： Korla fragrant pears weight-loss ratio damages storage time

Wind disturbance compensated path-following control for fixed-wing UAVs in arbitrarily strong winds

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Chinese Journal of Aeronautics 2024年第2期37卷 431-445页

作者： hao LU lan GAO Yunda YAN Mingzhe HOU Chenliang WANG Hangzhou Innovation Institute Beihang UniversityHangzhou 310051China School of Information Science and Technology Hangzhou Normal UniversityHangzhou 311121China Department of Computer Science University College LondonLondon WC1E 6BTUnited Kingdom Center for Control Theory and Guidance Technology Harbin Institute of TechnologyHarbin 150001China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

Wind is the primary challenge for low-speed fixed-wing unmanned aerial vehicles to follow a predefined flight *** cope with various wind conditions,this paper proposes a wind disturbance compensated path following control strategy where the wind disturbance estimate is incorporated with the nominal guiding vector field to provide the desired airspeed direction for the *** the control input vector for the outer-loop kinematic subsystem needs to satisfy a magnitude constraint,a scaling mechanism is introduced to tune the proportions of the compensation and nominal ***,an optimization problem is formulated to pursue a maximum wind compensation in strong winds,which can be solved analytically to yield two scaling factors.A cascaded inner-loop tracking controller is also designed to fulfill the outer-loop wind disturbance compensated guiding vector ***-fidelity simulation results under sensor noises and realistic winds demonstrate that the proposed path following algorithm is less sensitive to sensor noises,achieves promising accuracy in normal winds,and mitigates the deviation from a desired path in wild winds.

关键词： Path following Guiding vector field Wind disturbance Disturbance rejection Fixed wings

Correlating dynamic relaxation and viscoelasticity in metallic glasses

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 81-90页

作者： GuangHui Xing Qi hao Fan Zhu Yun-Jiang Wang Yong yang Hidemi Kato Eloi Pineda Si lan JiChao Qiao School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi'an 710072China State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China Department of Mechanical Engineering College of EngineeringCity University of Hong KongHong Kong 999077China Department of Materials Science and Engineering College of EngineeringCity University of Hong KongHong Kong 999077China Institute for Materials Research Tohoku UniversitySendai 980-8577Japan Department of Physics Institute of Energy TechnologiesUniversitat Politècnica de CatalunyaBarceona 9Spain School of Material Science and Engineering Herbert Gleiter Institute of NanoscienceNanjing University of Science and Technology.Nanjing 210094China State Key Laboratory of Clean and Efficient Turbomachinery Power Equipment Northwestern Polytechnical UniversityXi'an 710072China

Relaxation dynamics,essential for the structural evolution of non-equilibrium systems like glassy materials,remain ***,we explore relaxation dynamics and viscoelastic properties in three types of metallic glasses with distinctβrelaxation *** systems with significantβrelaxation,stress relaxation and creep experiments reveal a transition from two-step to one-step relaxation with rising ***,such a phenomenon is absent in systems with weakerβ*** model the two-step relaxation process using a double Kohlrausch-Williams-Watts equation,and the obtained relaxation times elegantly adhere to the Arrhenius *** combining fitted activation energies with theoretical analysis,we conclusively attribute these relaxation processes toβrelaxation andαrelaxation,***,we analyze the relaxation time spectra of two processes and establish a comprehensive picture linking dynamic relaxation with *** study provides new strategies for probing the complex relaxation behaviors of glasses from the perspective of viscoelasticity.

关键词： creep relaxation glasses

Snowpack variations and their hazardous effects under climate warming in the central Tianshan Mountains

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Advances in Climate Change Research 2024年第3期15卷 442-451页

作者： Jian-Sheng hao Yan WANG lan-Hai LI Key Laboratory of land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences(CAS)Beijing 100101China Xinjiang Key Laboratory of Water Cycle and Utilization in Arid Zone Urumqi 830011China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Tianshan Snowcover and Avalanche Observation and Research Station of Xinjiang Xinyuan 835800China CAS Research Center for Ecology and Environment of Central Asia Urumqi 830011China

Climate change alters snowpack evolution,which in turn influences the likelihood of snow avalanches and flood *** lack of systemic observational data on key snow characteristics in high mountains remains a scientific challenge in terms of systematically elucidating the dynamic chain of variations in climate-snowpack-snow *** restricts our understanding and poses challenges in the prediction of snow-related disaster *** such,this study analysed the variations of temperature and snowfall and the physical characteristics of snowpacks based on ground-based observations from the Kunse River Valley situated in the Tianshan Mountains from 1967 to *** results reveal that the temperature increased significantly by 0.32°C per decade(plands,road transportation,water-electricity infrastructure and several other human ***,these insights are critical for providing vital information that can deepen our understanding of the impact of climate change on snowpack characteristics and improve management strategies for snow-related disaster prevention and mitigation.

关键词： Climate change Snowpack variations Snow-related disaster Tianshan Mountains

Temperature inversion enables superior stability for low-temperature Zn-ion batteries

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Journal of Energy Chemistry 2024年第4期91卷 245-253页

作者： Fu-Da Yu Zhe-Jian Yi Rui-yang Li Wei-hao Lin Jie Chen Xiao-Yue Chen Yi-Ming Xie Ji-Huai Wu Zhang lan lan-Fang Que Bao-Sheng Liu hao Luo Zhen-Bo Wang Engineering Research Center of Environment-Friendly Functional Materials Ministry of EducationInstitute of Materials Physical ChemistryHuaqiao UniversityXiamen 361021FujianChina b2 School of Electronic Engineering Guangxi University of Science and TechnologyLiuzhou 545006GuangxiChina School of Materials Science and Engineering Xiamen University of TechnologyXiamen 361024FujianChina School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001HenanChina MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage State Key Laboratory of Space Power-SourcesSchool of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001HeilongjiangChina College of Materials Science and Engineering Shenzhen UniversityShenzhen 518071GuangdongChina

It is challenging for aqueous Zn-ion batteries(ZIBs)to achieve comparable low-temperature(low-T)performance due to the easy-frozen electrolyte and severe Zn ***,an aqueous electrolyte with a low freezing point and high ionic conductivity is *** with molecular dynamics simulation and multi-scale interface analysis(time of flight secondary ion mass spectrometry threedimensional mapping and in-situ electrochemical impedance spectroscopy method),the temperature independence of the V_(2)O_(5)cathode and Zn anode is observed to be ***,dominated by the solvent structure of the designed electrolyte at low temperatures,vanadium dissolution/shuttle is significantly inhibited,and the zinc dendrites caused by this electrochemical crosstalk are greatly relieved,thus showing an abnormal temperature inversion *** the disclosure and improvement of the above phenomena,the designed Zn||V_(2)O_(5)full cell delivers superior low-T performance,maintaining almost 99%capacity retention after 9500 cycles(working more than 2500 h)at-20°*** work proposes a kind of electrolyte suitable for low-T ZIBs and reveals the inverse temperature dependence of the Zn anode,which might offer a novel perspective for the investigation of low-T aqueous battery systems.

关键词： Aqueous Zn-ion batteries Low-temperature performance Opposite temperature dependence Zndendrite growth Vanadium dissolution

Recent progress in photocatalytic NAD(P)H regeneration for photocatalytic-enzymatic-coupling system

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Frontiers of Chemical Science and Engineering 2024年第4期18卷 1-24页

作者： Wei lan Maodi Wang Huicong Dai Qihua yang Key Laboratory of the Ministry of Education for Advanced Catalysis Materials Zhejiang Key Laboratory for Reactive Chemistry on Solid SurfacesInstitute of Physical ChemistryZhejiang Normal UniversityJinhua 321004China

The enzymatic redox reactions in natural photosynthesis rely much on the participation of cofactors,with reduced nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate(NADH/NADPH)or their oxidized form(NAD+/NADP+)as an important redox *** photocatalytic regeneration of expensive and unstable NADH/NADPH in vitro is an important process in enzymatic reduction and has attracted much research *** different types of photocatalysts have been developed for photocatalytic NADH/NADPH regeneration,the efficiency is still relatively *** elucidate the key factors affecting the performance of photocatalytic NADH/NADPH regeneration is helpful to rationally design the photocatalyst and improve the photocatalytic *** this paper,we overview the recent progress in photocatalytic NADH/NADPH regeneration with the focus on the strategies to improve the visible light adsorption,the charge separation and migration efficiency,as well as the surface reaction,which jointly determine the overall photocatalytic regeneration *** potential development of photocatalytic NADH/NADPH regeneration and photocatalyticenzymatic-coupling system is prospected finally.

关键词： photocatalytic-enzymatic coupling NAD(P)H regeneration photocatalysis efficiency

Bioinspired supramolecular macrocycle hybrid membranes with enhanced proton conductivity

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Nano Research 2024年第2期17卷 797-805页

作者： Pengfei yang Linlin Xu Panagiotis Trogadas Marc-Olivier Coppens yang lan Centre for Nature Inspired Engineering Department of Chemical EngineeringUniversity College LondonLondon WC1E 7JEUK

Enhancing the proton conductivity of proton exchange membranes(PEMs)is essential to expand the applications of proton exchange membrane fuel cells(PEMFCs).Inspired by the proton conduction mechanism of bacteriorhodopsin,cucurbit[n]urils(CB[n],where n is the number of glycoluril units,n=6,7,or 8)are introduced into sulfonated poly(ether ether ketone)(SPEEK)matrix to fabricate hybrid PEMs,employing a nature-inspired chemical engineering(NICE)*** carbonyl groups of CB[n]act as proton-conducting sites,while the host–guest interaction between CB[n]and water molecules offers extra protonconducting ***,the molecular size of CB[n]aids in their dispersion within the SPEEK matrix,effectively bridging the unconnected proton-conducting sulfonic group domains within the SPEEK ***,all hybrid membranes exhibit significantly enhanced proton ***,the SPEEK membrane incorporating 1 wt.%CB[8](CB[8]/SPEEK-1%)demonstrates the highest proton conductivity of 198.0 mS·cm^(−1) at 60°C and 100%relative humidity(RH),which is 228%greater than that of the pure SPEEK membrane under the same ***,hybrid membranes exhibit superior fuel cell *** CB[8]/SPEEK-1%membrane achieves a maximum power density of 214 mW·cm^(−2),representing a 140%improvement over the pure SPEEK membrane(89 mW·cm^(−2))at 50°C and 100%*** findings serve as a foundation for constructing continuous proton-conducting pathways within membranes by utilizing supramolecular macrocycles as fuel cell electrolytes and in other applications.

关键词： supramolecular macrocycle proton conductivity cucurbit[n]uril proton exchange membrane fuel cell

Rapid interrogation of special nuclear materials by combining scattering and transmission nuclear resonance fluorescence spectroscopy

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Nuclear Science and Techniques 2021年第8期32卷 67-77页

作者： hao-yang lan Tan Song Jia-Lin Zhang Jian-Liang Zhou Wen Luo School of Nuclear Science and Technology University of South ChinaHengyang 421001China National Exemplary Base for International Sci.&Tech. Collaboration of Nuclear Energy and Nuclear SafetyUniversity of South ChinaHengyang 421001China

The smuggling of special nuclear materials(SNMs)across national borders is becoming a serious threat to nuclear *** paper presents a feasibility study on the rapid interrogation of concealed SNMs by combining scattering and transmission nuclear resonance fluorescence(s NRF and t NRF)*** s NRF spectroscopy,SNMs such as^(235,238)U are excited by a wide-band photon beam of appropriate energy and exhibit unique NRF *** Carlo simulations show that one-dimensional scans can realize isotopic identification of concealed^(235,238)U when the detector array used for interrogation has sufficiently high energy *** simulated isotopic ratio^(235U/238)U is in good agreement with the theoretical value when the SNMs are enclosed in relatively thin *** interrogation is followed by t NRF spectroscopy using a narrow-band photon beam with the goal of obtaining tomographic images of the concealed *** reconstructed image clearly reveals the position of the isotope^(235)U inside an iron *** is shown that the interrogation time of s NRF and t NRF spectroscopy is one order of magnitude lower than that when only t NRF spectroscopy is used and results in a missed-detection rate of 10^(-3).The proposed method can also be applied for isotopic imaging of other SNMs such as^(239,240)Pu and^(237)Np.

关键词： Special nuclear material Nondestructive interrogation Nuclear resonance fluorescence