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Classification of Sailboat Tell Tail Based on Deep Learning

Journal of Ocean University of China 2024年第3期23卷 710-720页

作者： CHANG Xiaofeng YU Jintao gao ying DING Hongchen LIU Yulong YU Huaming Department of Physical Education Ocean University of ChinaQingdao 266100China College of Big Data Qingdao University of Science and TechnologyQingdao 266061China College of Oceanic and Atmospheric Sciences Ocean University of ChinaQingdao 266100China

The tell tail is usually placed on the triangular sail to display the running state of the air flow on the sail *** is of great significance to make accurate judgement on the drift of the tell tail of the sailboat during sailing for the best sailing *** it is difficult for sailors to keep an eye for a long time on the tell sail for accurate judging its changes,affected by strong sunlight and visual *** this case,we adopt computer vision technology in hope of helping the sailors judge the changes of the tell tail in ease with *** paper proposes for the first time a method to classify sailboat tell tails based on deep learning and an expert guidance system,supported by a sailboat tell tail classification data set on the expert guidance system of interpreting the tell tails states in different sea wind conditions,including the feature extraction *** the expression capabilities that vary with the computational features in different visual tasks,the paper focuses on five tell tail computing features,which are recoded by an automatic encoder and classified by a SVM *** experimental samples were randomly divided into five groups,and four groups were selected from each group as the training set to train the *** remaining one group was used as the test set for *** highest resolution value of the ResNet network was 80.26%.To achieve better operational results on the basis of deep computing features obtained through the ResNet network in the *** method can be used to assist the sailors in making better judgement about the tell tail changes during sailing.

关键词： tell tail sailboat classification deep learning

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S-,P-stabilized bromoallenes for modular allenylborylation of alkenes

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Science China Chemistry 2024年第1期67卷 360-367页

作者： Jixin Wang Donghao Luo ying Hu Zhili Duan Jianlin Yao Konstantin Karaghiosoff jie Li Key Laboratory of Organic Synthesis of Jiangsu Province Suzhou Key Laboratory of Pathogen Bioscience and Anti-infective MedicineCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou 215123China Department Chemie Ludwig-Maximilians-Universitat MunchenButenandtstr.5-13Haus F81377 MunichGermany State Key Laboratory and Institute of Elemento-Organic Chemistry Haihe Laboratory of Sustainable Chemical TransformationsCollege of ChemistryNankai UniversityTianjin 300071China

Simultaneously forming a carbon-carbon and a carbon-heteroatom bond in a single step through transition metal-catalyzed alkene difunctionalization strategy has emerged as a powerful tool for synthetic organic *** to the uncontrollable reactivity,direct cross-coupling with bromoallenes as the building blocks for the selective allenation and borylation remains *** herein report a new type of S-and P-stabilized bromoallenes for palladium-catalyzed modular allenation and borylation of alkenes to the divergent synthesis of multiply functionalized allenes in a highly regio-and diastereoselective *** reaction features broad substrate scope and wide functional group compatibility,thus providing a straightforward method to install allenyl and boryl groups across *** experiments highlight the crucial importance of S-,P-stabilization for the oxidative insertion of Pd-species into the allenyl-Br *** facile syntheses of bioactive allenic steroids and exocyclic allenes demonstrate the synthetic utility of this protocol.

关键词： alkene difunctionalization olefins bromoallenes allenylborylation palladium

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Fusion of Ground-Based and Spaceborne Radar Precipitation Based on Spatial Domain Regularization

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Journal of Meteorological Research 2024年第2期38卷 285-302页

作者： Anfan HUANG Leilei KOU Yanzhi LIANG ying MAO Haiyang gao Zhigang CHU School of Atmospheric Physics Nanjing University of Information Science&TechnologyNanjing 210044 Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing 210044

High-quality and accurate precipitation estimations can be obtained by integrating precipitation information measures using ground-based and spaceborne radars in the same target *** the true precipitation state is a typical inverse problem for a given set of noisy radar precipitation *** regularization method can appropriately constrain the inverse problem to obtain a unique and stable *** different types of precipitation with different prior distributions,the L_(1) and L_(2) norms were more effective in constraining stratiform and convective precipitation,*** a combination of L_(1) and L_(2) norms,the Huber norm is more suitable for mixed precipitation *** study uses different regularization norms to combine precipitation data from the C-band dual-polarization ground radar(CDP)and dual-frequency precipitation radar(DPR)on the Global Precipitation Measurement(GPM)mission core *** to single-source radar data,the fused figures contain more information and present a comprehensive precipitation structure encompassing the reflectivity and precipitation *** 27 precipitation cases,the fusion results utilizing the Huber norm achieved a structural similarity index measure(SSIM)and a peak signal-to-noise ratio(PSNR)of 0.8378 and 30.9322,respectively,compared with the CDP *** fusion results showed that the Huber norm effectively amalgamate the features of convective and stratiform precipitation,with a reduction in the mean absolute error(MAE;16.1%and 22.6%,respectively)and root-mean-square error(RMSE;11.7%and 13.6%,respectively)compared to the 1-norm and ***,in contrast to the fusion results of scale recursive estimation(SRE),the Huber norm exhibits superior capability in capturing the localized precipitation intensity and reconstructing the detailed features of precipitation.

关键词： dual-frequency precipitation radar(DPR) dual-polarization radar data fusion regularization Huber norm

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Precise immobilization of metal single atoms into a porphyrinic metal-organic framework for an efficient alkene hydrosilylation

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Nano Research 2024年第7期17卷 5914-5921页

作者： Chun-ying Chen Qi-jie Mo Fu-Zhen Li Hai-Li Song Li Zhang MOE Laboratory of Bioinorganic and Synthetic Chemistry Lehn Institute of Functional MaterialsSchool of ChemistrySun Yat-Sen UniversityGuangzhou 510006China

Alkene hydrosilylation is one of the most concise and atom-economical methods to synthesize organosilicon ***,we reported the precise immobilization of metal single atoms(M-SAs;M=Ru,Rh,Ir,Pd,Pt,and Au)into a porphyrinic metalorganic framework(MOF)of PCN-222(PCN=porous coordination network),and then applied the resultant MOF composites of M-SAs@PCN-222 to alkene *** solvent-free conditions,Pt-SAs@PCN-222 displayed an especially high catalytic efficiency with the turnover frequency up to 119 s−1 and the maximum turnover number of 906,250 at room *** and theoretical studies revealed that there existed strong interactions between Pt-SAs@PCN-222 and the substrates,which helped to condense the substrates in the cavities of the porous *** density functional theory calculations and molecular dynamics simulations disclosed that PCN-222 could transfer electrons to Pt-SAs to enhance the silane oxidative addition and drive the reaction to proceed smoothly via Chalk–Harrod pathway.

关键词： alkene hydrosilylation single atom catalysts metal-organic frameworks precision chemistry synergistic catalysis

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Modelling and validation of flash flood inundation in drylands

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Journal of Geographical Sciences 2024年第1期34卷 185-200页

作者： gao Dan YIN jie WANG Dandan YANG Yuhan LU Yi CHEN Ruishan School of Geographic Sciences East China Normal UniversityShanghai 200241China Key Laboratory of Geographic Information Science of Ministry of Education East China Normal UniversityShanghai 200241China National Disaster Reduction Center of China Ministry of Emergency Management of People's Republic of ChinaBeijing 100124China School of Design Shanghai Jiao Tong UniversityShanghai 200240China

In the context of climate change and human activities,flood disasters in arid mountainous areas have become increasingly frequent,and seriously threatened the safety of people's lives and *** and accurate flash flood inundation modelling is an essential foundational research area,which can aid in the reduction of casualties and the minimization of disaster losses;however,this modelling is also very difficult,and models need to be urgently developed to address flash flood forecasting and *** objective of this study is to construct a numerical modelling method for flash floods in *** on a 2D high-resolution flood numerical model(Flood Map-Hydro Inundation2D),we hindcasted the dynamic process of flash flooding and show the spatio-temporal characteristics of flash flood inundation for the“8·18”flash flood disaster that occurred in Datong county,Qinghai *** results showed that the model output effectively agreed with the observed inundation after the event in terms of both spatial extent and temporal *** flooding mainly occurred between 00:00 and 01:00 on August 18,***,Hejiazhuang and Longwo villages were affected most *** further conducted model sensitivity analysis and found that the model was highly sensitive to both roughness and hydraulic conductivity in drylands,and the effect of hydraulic conductivity was more *** study confirmed the good performance of our model for the simulation of flash flooding in arid areas and provides a potential method for flash flood assessment and management in arid areas.

关键词： flash flood numerical modelling arid areas Datong county Flood Map-Hydro Inundation2D

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Encouraging Solution to the Problem of Synthesizing Protein α-Thioester

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Chinese Journal of Chemistry 2024年第10期42卷 1114-1120页

作者： Xinliang Liu Zijun gao jie Zhao Farong Ye Ping Huang Ping Wang Center for Chemical Glycobiology Shanghai Key Laboratory for Molecular Engineering of Chiral DrugsFrontiers Science Center for Transformative MoleculesSchool of Chemistry and Chemical EngineeringZhangjiang Institute for Advanced StudyShanghai JiaoTongUniversityShanghai 200240China Shenzhen Research Institute of Shanghai Jiao Tong University ShenzhenGuangdong 518057China

Expressed protein ligation(EPL)provides a powerful tool to access large-size proteins with precise *** methods for constructing the critical protein thioester for EPL have predominantly relied on the recombinant intein fusion expressed in Escherichia coli(***).Despite its powerful applications,the expression of thioester derived from eukaryotic protein in *** inherently suffers from its limited solubility,the inactivity of intein,premature hydrolysis and low *** overcome these obstacles,we present herein the facile one-flask synthesis of inaccessible proteinα-thioester via a SUMO-protein-intein(SPI)sandwich *** utility of SUMO enhances the protein fusion yield and solubility,prevents premature hydrolysis and simplifies the purification *** inaccessible protein thioester with internal Cys residues can be readily produced and is compatible with the EPL-desulfurization protocol used to prepare complex proteins,which is otherwise difficult to obtain using traditional *** utility has been highlighted through the synthesis of human granulocyte colony-stimulating factor(G-CSF).

关键词： Desulfurization Glycoproteins Glycopeptides Protein expression Peptide thioester

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Unsaturated bi-heterometal clusters in metal-vacancy sites of 2D MoS2 for efficient hydrogen evolution

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Carbon Energy 2024年第3期6卷 264-275页

作者： Gonglei Shao jie Xu Shasha gao Zhang Zhang Song Liu Xu Zhang Zhen Zhou Interdisciplinary Research Center for Sustainable Energy Science and Engineering(IRC4SE2) School of Chemical EngineeringZhengzhou UniversityZhengzhouHenanChina College of Chemistry and Materials Engineering Wenzhou UniversityWenzhouZhejiangChina Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) College of ChemistryNankai UniversityTianjinChina State Key Laboratory of Chemo/Biosensing and Chemometrics Institute of Chemical Biology and Nanomedicine(ICBN)College of Chemistry and Chemical EngineeringHunan UniversityChangshaHunanChina Institute of New Energy Material Chemistry School of Materials Science and EngineeringNankai UniversityTianjinChina

The valence states and coordination structures of doped heterometal atoms in two-dimensional(2D)nanomaterials lack predictable regulation ***,a robust method is proposed to form unsaturated heteroatom clusters via the metal-vacancy restraint mechanism,which can precisely regulate the bonding and valence state of heterometal atoms doped in 2D molybdenum *** unsaturated valence state of heterometal Pt and Ru cluster atoms form a spatial coordination structure with Pt–S and Ru–O–S as catalytically active *** them,the strong binding energy of negatively charged suspended S and O sites for H+,as well as the weak adsorption of positively charged unsaturated heterometal atoms for H*,reduces the energy barrier of the hydrogen evolution reaction proved by theoretical ***,the electrocatalytic hydrogen evolution performance is markedly improved by the ensemble effect of unsaturated heterometal atoms and highlighted with an overpotential of 84 mV and Tafel slope of 68.5 mV dec^(−1).In brief,this metal vacancy-induced valence state regulation of heterometal can manipulate the coordination structure and catalytic activity of heterometal atoms doped in the 2D atomic lattice but not limited to 2D nanomaterials.

关键词： clusters hydrogen evolution reaction metal vacancy MoS2 unsaturated heterometal

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The effect of seismic action on stability of saline soil subgrade in cold region based on isothermal stratification method

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Earthquake Research Advances 2024年第3期4卷 66-81页

作者： jie Cheng Yu Zhang ying Ma Xuerui Chen Ning An School of Traffic and Transportation Lanzhou Jiaotong UniversityLanzhou730070China Key Laboratory of Railway Industry of Plateau Railway Transportation Intelligent Management and Control Lanzhou Jiaotong UniversityLanzhou730070China Gansu Institute of Engineering Geology Lanzhou730030China

With the change of seasons, the shear strength of saline soil subgrade filler will change with the change of external temperature, which will aggravate the adverse effects of seismic on the subgrade. To explore the influence of seismic action on the stability of saline soil subgrade under the influence of temperature on the strength of saline soil subgrade filler, this paper first carried out saline soil shear tests at different temperatures to obtain the influence of temperature on the shear strength of saline soil. Then, the temperature field of the saline soil subgrade was simulated, and then based on the subgrade isothermal stratification model and FLAC3D, the displacement and acceleration amplification effects of seismic action on the shady slope, sunny slope and subgrade of saline soil subgrade in different months were analyzed. The following conclusions were finally drawn: under the action of seismic, In the process of the change of subgrade temperature of Qarhan-Golmud Expressway between 7.7°C and 27°C, the change of saline soil cohesion is the main factor affecting the stability of subgrade slope, and the maximum and minimum values of subgrade surface settlement appear in September and June of each year,respectively. In August, the differences of settlement between the shady slope and the sunny slope shoulder of the subgrade were the largest, and the acceleration of the shady slope and the sunny slope and the inside of the subgrade changed most significantly in the vertical direction. Special attention should be paid to the seismic early warning in the above key months;In the range from both sides of the shoulder to the centerline of the roadbed,the acceleration amplification effect starts to increase significantly from about 3m from the centerline of the roadbed to the centerline, so it is necessary to pay attention to the seismic design of this range.

关键词： Subgrade stability Saline soils Acceleration amplification effect Seismic design

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Microstructure and properties of 35 kg large aluminum alloy flywheel housing components formed by squeeze casting with local pressure compensation

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China Foundry 2024年第5期21卷 563-576页

作者： Ju-fu Jiang Jing Yan ying-ze Liu Ning Ge ying Wang Chang-jie Ding De-chao Zou School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of Mechatronics Engineering Harbin Institute of TechnologyHarbin 150001China Dalian Innovation Die-casting Co. Ltd.Dalian 116600LiaoningChina

The squeeze casting method with local pressure compensation was proposed to form a flywheel housing component with a weight of 35 *** numerical simulation,microstructure observation and phase characterization were performed,and the influence of local pressure compensation on feeding of thick-wall position,microstructure and mechanical properties of the formed components were *** show that the molten metal keeps a good fluidity and the filling is complete during the filling *** the solidification at thick-wall positions of the mounting ports is slow,the local pressure compensation effectively realizes the local forced feeding,significantly eliminating the shrinkage cavity *** the microstructure of AlSi9Mg alloy,α-Al primarily consists of fragmented dendrites and rosette grains,while eutectic Si predominantly comprises needles and short *** impact of local pressure compensation on strength is relatively minimal,yet its influence on elongation is *** local pressure compensation,the average elongation at the compensated areas is 9.18%,which represents a 44.90%higher than that before *** average tensile strength is 209.1 MPa,and the average yield strength is 100.6 *** local pressure compensation can significantly reduce or even eliminate the internal defects in the 35 kg large-weight components formed by squeeze casting.

关键词： squeeze casting local pressure compensation aluminum alloy microstructure mechanical properties large flywheel housing components

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A discontinuous collocated-grid implementation for high-order finite-difference modeling

A discontinuous collocated-grid implementation for high-orde...

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中国科学院地质与地球物理研究所2015年度（第15届）学术年会

作者： Na Fan Lian-Feng Zhao ying-jie gao Zhen-Xing Yao Chinese Academy of Sciences Institute of Geology and Geophysics Key Laboratory of Earth and Planetary Physics and University of Chinese Academy of Sciences Chinese Academy of Sciences Institute of Geology and Geophysics Key Laboratory of Earth and Planetary Physics

The discontinuous-grid method can greatly reduce the storage requirements and computational costs of finite-difference(FD) modeling for large-velocity-contrast ***, traditional discontinuous-grid methods have to use interpolation when refining the wavefield in transition zones and would cause apparent artifacts. We have developed a new discontinuous collocated-grid scheme for highorder FD modeling. We refined the wavefield on a rotated coordinate system, where the interpolation is not required again. The horizontal and vertical spatial derivatives can be accurately converted into diagonal derivatives within the rotated coordinate system;thus, our scheme would be free of artifacts caused by improper interpolation. The ratio from coarse- to fine-grid spacing is restricted to 2n for our scheme,where n is a positive integer. Numerical experiments demonstrate that the proposed discontinuous collocated-grid scheme reduces the artificial reflections by about two orders of magnitude compared to the interpolation scheme and yields a wavefield that is almost identical to that of the uniform-grid simulation. The rotated FD operator with arbitrary even-order accuracy is applied in the transition zones;thus, it significantly improves the spatial accuracy while saving computational cost.

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