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Microphysical Insights into a Tornadic Supercell from Dual-Polarization Radar Observations in Jiangsu, China on 14 May 2021

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Journal of Meteorological Research 2024年第2期38卷 303-320页

作者： Chao yuan Yang bai Pengfei SUN Hua bai Lu XIA China Meteorological Administration Tornado Key Laboratory Foshan 528315 Institute of Atmospheric Environment China Meteorological AdministrationShenyang 110166 Panjin National Climate Observatory Panjin 124010 Yangzhou Meteorological Bureau of Jiangsu Province Yangzhou 225100 Yichun Meteorological Bureau of Heilongjiang Province Yichun 153000

Tornadoes are incredibly powerful and destructive natural events,yet the microphysical characteristics of the parent storm and its effects on tornadogenesis remain *** study analyzed polarization radar data of a tornadic supercell that occurred in Jiangsu Province of China on 14 May 2021,in comparison with another tornadic supercell and two non-tornadic supercells that occurred in the same region in *** two tornadic supercells exhibited lower differential reflectivity(ZDR)in the hook echo region compared with the non-tornadic supercells,indicating smaller median drop sizes.A distinct increase in ZDR from the melting of frozen hydrometeors,observed between2.5-and 4.0-km altitude in the non-tornadic storms,was absent in the tornadic *** non-tornadic supercells also displayed substantially higher specific differential phase(KDP)below the melting level,likely aroused from enhanced melting and *** findings suggest fundamental microphysical contrasts between tornadic and nontornadic ***,tornadic supercells have smaller droplets and may reduce melting in hook ***,greater separation between the ZDR arc and the KDP foot was observed during *** vertical gradient of KDP related to the cooling pool strength of the hook echo,regulating rear-flank downdraft *** the limited number of cases investigated,the findings of this study indicate that monitoring ZDR,KDP,and drop size distribution trends could assist with tornado prediction and warnings.

关键词： tornado polarimetric radar supercell hook echo drop size distribution

Optical system for extremely large spectroscopic survey telescope

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 158-174页

作者： Ding-qiang Su Hua bai Xiangyan yuan Xiangqun Cui Key Laboratory of the Ministry of Education School of Astronomy and Space ScienceNanjing UniversityNanjing 210023China Nanjing Institute of Astronomical Optics and Technology(NIAOT) Chinese Academy of SciencesNanjing 210042China University of Chinese Academy of Sciences Nanjing 211135China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 101408China

This article presents research work on a spectroscopic survey *** idea is as follows:for such a telescope,a pure reflecting optical system is designed,which should have an aperture and a field of view(FOV)both as large as possible and excellent image quality,and then a strip lensm(lens-prism)atmospheric dispersion corrector(S-ADC)is added,only for correcting the atmospheric *** the fund limitation and the simplicity of scaling up,some 12-m telescopes are designed as ***,Korsch,and Meinel put forward the four-mirror Nasmyth systems I and II,which are used in this *** of 1.5°,2°,and 2.5°are *** all systems,the image qualities are *** the S-ADC relaxes the optical glass size restriction,this 12-m telescope with a FOV of 2.5°can be magnified in proportion to a 16-m *** etendue(from Frenchétendue)and focal surface will now be the largest in the *** such a telescope,a pure reflecting optical system can also be obtained.A subsequent coudésystem is designed with excellent image quality.

关键词： telescopes spectroscopic survey

FCF-LDH/BiVO4 with synergistic effect of physical enrichment and chemical adsorption for efficient reduction of nitrate

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Green Energy & Environment 2024年第7期9卷 1112-1121页

作者： Yajie bai Zhenyuan fang Yong Lei Lijing Liu Huaiquan Zhao Hongye bai Weiqiang Fan Weidong Shi School of Chemistry and Chemical Engineering Jiangsu University School of Chemistry Beihang University Institute of Physics & IMN MacroNano Technische Universit?t Ilmenau

Photoelectrochemical NO3-reduction（PEC NITRR） not only provides a promising solution for promoting the global nitrogen cycle,but also converts NO3-to the important chemicals（NH3）.However,it is still a great challenge to prepare catalysts with excellent NO3-adsorption/activation capacity to achieve high ***,we designed a novel Fe2+～Cu2+Fe3+LDH/BiVO4（FCF-LDH/BVO） catalyst with synergistic effect of chemical adsorption and physical ***2+in FCF-LDH/BVO provides the rich Lewis acid sites for the adsorption of NO3-,and the appropriate layer spacing of FCF-LDH further promotes the physical enrichment of NO3-in its interior,thus realizing the effective contact between NO3-and active sites(Fe2+).FCF-LDH/BVO showed excellent NH3production performance(FENH3=66.1%,rNH3=13.8 μg h-1cm-2) and selectivity(FENO2-=2.5%,rNO2-=4.9 μg h-1cm-2) in 0.5 mol *** addition,FCF-LDH/BVO maintains the desirable PEC stability for six cycle experiments,showing great potential for practical ***14NO3-and15NO3-isotope test provides strong evidence for further verification of the origin of N in the generated *** LDH catalyst has a great potential in PEC removal of NO3-from groundwater.

关键词： LDH Lewis acid sites Physical enrichment Photoelectrochemical NO 3 − Reduction Ammonia

Reliable calculations of nuclear binding energies by the Gaussian process of machine learning

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Nuclear Science and Techniques 2024年第6期35卷 130-144页

作者： Zi-Yi yuan Dong bai Zhen Wang Zhong-Zhou Ren School of Physics Science and Engineering Tongji UniversityShanghai 200092China College of Science Hohai UniversityNanjing 211100China Key Laboratory of Advanced Micro-Structure Materials Ministry of EducationShanghai 200092China

Reliable calculations of nuclear binding energies are crucial for advancing the research of nuclear physics. Machine learning provides an innovative approach to exploring complex physical problems. In this study, the nuclear binding energies are modeled directly using a machine-learning method called the Gaussian process. First, the binding energies for 2238 nuclei with Z > 20 and N > 20 are calculated using the Gaussian process in a physically motivated feature space, yielding an average deviation of 0.046 MeV and a standard deviation of 0.066 MeV. The results show the good learning ability of the Gaussian process in the studies of binding energies. Then, the predictive power of the Gaussian process is studied by calculating the binding energies for 108 nuclei newly included in AME2020. The theoretical results are in good agreement with the experimental data, reflecting the good predictive power of the Gaussian process. Moreover, the α-decay energies for 1169 nuclei with 50 ≤ Z ≤ 110 are derived from the theoretical binding energies calculated using the Gaussian process. The average deviation and the standard deviation are, respectively, 0.047 MeV and 0.070 MeV. Noticeably, the calculated α-decay energies for the two new isotopes ^ (204 )Ac(Huang et al. Phys Lett B 834, 137484(2022)) and ^ (207) Th(Yang et al. Phys Rev C 105, L051302(2022)) agree well with the latest experimental data. These results demonstrate that the Gaussian process is reliable for the calculations of nuclear binding energies. Finally, the α-decay properties of some unknown actinide nuclei are predicted using the Gaussian process. The predicted results can be useful guides for future research on binding energies and α-decay properties.

关键词： Nuclear binding energies decay Machine learning Gaussian process

Data-driven discovery of linear dynamical systems from noisy data

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Science China(Technological Sciences) 2024年第1期67卷 121-129页

作者： WANG YaSen yuan Ye fang HuaZhen DING Han School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China State Key Lab of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China School of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhan 430074China Department of Mechanical Engineering University of KansasLawrence 66045USA

In modern science and engineering disciplines,data-driven discovery methods play a fundamental role in system modeling,as data serve as the external representations of the intrinsic mechanisms within ***,empirical data contaminated by process and measurement noise remain a significant obstacle for this type of *** this study,we have developed a data-driven method capable of directly uncovering linear dynamical systems from noisy *** method combines the Kalman smoothing and sparse Bayesian learning to decouple process and measurement noise under the expectation-maximization framework,presenting an analytical method for alternate state estimation and system ***,the discovered model explicitly characterizes the probability distribution of process and measurement noise,as they are essential for filtering,smoothing,and stochastic *** have successfully applied the proposed algorithm to several simulation *** results demonstrate its potential to enable linear dynamical system discovery in practical applications where noise-free data are intractable to capture.

关键词： system identification sparse Bayesian learning Kalman smoothing process and measurement noise

Observing eddy dye patches induced by shear instabilities in the surf zone on a plane beach

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Acta Oceanologica Sinica 2024年第3期43卷 15-29页

作者： Chunping Ren Nannan Fu Chong Yu Yuchuan bai Kezhao fang State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China College of Water Resource Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China

The effects of surf zone eddy generated by alongshore currents on the deformation and transport of dye are still poorly understood,and related tracer release experiments are ***,a tracer release laboratory experiment was conducted under monochromatic,unidirectional incident waves with a large incident angle(30°)on a plane beach with a 1:100 slope in a large wave basin.A charge-coupled device suspended above the basin recorded the dye patch *** evolution of eddy dye patch was observed and the transport and diffusion were analyzed based on the collected ***,a linear instability numerical model was adopted to calculate the perturbation velocity field at the initial *** observation and image processing results show that surf zone eddy patches occurred and were separated from the original dye *** numerical analysis results demonstrate that the structure of the perturbation velocity field is consistent with the experimental observations,and that the ejection of eddy patches shoreward or offshore may be ascribed to the double vortex.

关键词： surf zone tracer release experiment evolution of eddy patch shear instability of alongshore currents

Photonic neuromorphic architecture for tens-of-task lifelong learning

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Light(Science & Applications) 2024年第3期13卷 519-530页

作者： yuan Cheng Jianing Zhang Tiankuang Zhou Yuyan Wang Zhihao Xu Xiaoyun yuan Lu fang Sigma Laboratory Department of Electronic EngineeringTsinghua UniversityBeijing 100084China Beijing National Research Center for Information Science and Technology(BNRist) Beijing 100084China Institute for Brain and Cognitive Science Tsinghua University(THUIBCS)Beijing 100084China

Scalable,high-capacity,and low-power computing architecture is the primary assurance for increasingly manifold and large-scale machine learning *** electronic artificial agents by conventional power-hungry processors have faced the issues of energy and scaling walls,hindering them from the sustainable performance improvement and iterative multi-task *** to another modality of light,photonic computing has been progressively applied in high-efficient neuromorphic ***,we innovate a reconfigurable lifelong-learning optical neural network(L2 ONN),for highly-integrated tens-of-task machine intelligence with elaborated algorithm-hardware *** from the inherent sparsity and parallelism in massive photonic connections,L2 ONN learns each single task by adaptively activating sparse photonic neuron connections in the coherent light field,while incrementally acquiring expertise on various tasks by gradually enlarging the *** multi-task optical features are parallelly processed by multi-spectrum representations allocated with different *** evaluations on freespace and on-chip architectures confirm that for the first time,L2 ONN avoided the catastrophic forgetting issue of photonic computing,owning versatile skills on challenging tens-of-tasks(vision classification,voice recognition,medical diagnosis,etc.)with a single ***,L2 ONN achieves more than an order of magnitude higher efficiency than the representative electronic artificial neural networks,and 14×larger capacity than existing optical neural networks while maintaining competitive performance on each individual *** proposed photonic neuromorphic architecture points out a new form of lifelong learning scheme,permitting terminal/edge AI systems with light-speed efficiency and unprecedented scalability.

关键词： life neural versatile

Photocatalytic synthesis of small-molecule drugs by porous framework materials

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Chinese Chemical Letters 2024年第3期35卷 52-65页

作者： Yingying Zhao Jiangpei yuan Lei Zhu Yu fang State Key Laboratory of Chemo/Bio-Sensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China Innovation Institute of Industrial Design and Machine Intelligence Quanzhou-Hunan University Quanzhou 362801China

Small-molecule drugs are widely used in daily *** are still issues with the current industrial synthesis techniques for small-molecule drugs,such as the use of expensive metal catalysts,convoluted reaction processes,and non-recyclable *** benefits of photocatalytic organic synthesis over conventional techniques are mild conditions,environmental friendliness,and great *** framework materials can precisely modulate catalytic sites'electronic state and ligand structure to improve photocatalytic *** particular,MOFs,COFs and PCCs based photocatalysts have received extensive research interest due to their unique morphology,structural adjustability,high photocatalytic performance,unique recyclability,excellent chemical stability,easy synthesis and low ***,a key area for future research is the development of porous framework materials as photocatalysts for the synthesis of small-molecule drugs or drug precursors.

关键词： Small-molecule drug Porous framework materials Photocatalysis

Flower-like tin oxide membranes with robust three-dimensional channels for efficient removal of iron ions from hydrogen peroxide

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Chinese Journal of Chemical Engineering 2024年第1期65卷 1-7页

作者： Risheng Shen Shilong Li Yuqing Sun yuan bai Jian Lu Wenheng Jing State Key Laboratory of Materials-Oriented Chemical Engineering Nanjing Tech UniversityNanjing 210009China National Energy Group Science and Technology Research Institute Co. Ltd.Nanjing 210023China

Membrane technology has become the mainstream process for the production of electronic grade hydrogen peroxide(H_(2)O_(2)).But due to the oxidation degradation of the organic membranes(***)by the strong oxidative radicals(e.g.OH)generated via the activation of H_(2)O_(2)by iron ions(Fe^(3+)),the short effective lifetime of membranes remains a *** nano tin oxide(SnO_(2))has great potential for the removal of Fe^(3+)in strongly oxidative H_(2)O_(2)because of its ability to stabilize H2O_(2)and preferentially adsorb Fe^(3+).Herein,we have designed for the first time a flower-like robust SnO_(2)membrane on the ceramic support by in situ template-free one-step hydrothermal *** three-dimensional loose pore structure in the membrane built by interlacing SnO_(2)nanosheets endows the SnO_(2)membrane with a high specific surface area and abundant adsorption sites(AOH).Based on the coordination complexation and electrostatic attraction between the SnO_(2)surface and Fe^(3+),the membrane shows a high Fe3+removal efficiency(83%)and permeability(24 L·m^(-2)·h^(-1)·MPa^(-1))in H_(2)O_(2).This study provides an innovative and simple approach to designing robust SnO_(2)membranes for highly efficient removal of Fe^(3+)in harsh environments,such as strong oxidation conditions.

关键词： Hydrogen peroxide SnO_(2)membrane Adsorption Hydrothermal