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Potential Distribution of Seagrass Meadows Based on the MaxEnt Model in Chinese Coastal Waters

Journal of Ocean University of China 2022年第5期21卷 1351-1361页

作者： wang Ming wang yong LIU Guangliang chen Yuhu YU Naijing Center for High Performance Computing and System Simulation Pilot National Laboratory for Marine Science and TechnologyQingdao 266200China Shandong Provincial Key Laboratory of Computer Networks Qilu University of Technology(Shandong Academy of Sciences)Jinan 250101China

Seagrass meadows are generally diverse in China and have become important ecosystem with essential functions.However,the seagrass distribution across the seawaters of China has not been evaluated,and the magnitude and direction of changes in seagrass meadows remain unclear.This study aimed to provide a nationwide seagrass distribution map and explore the dynamic changes in seagrass population under global climate change.Simulation studies were performed using the modeling software MaxEnt with 58961 occurrence records and 27 marine environmental variables to predict the potential distribution of seagrasses and calculate the area.Seven environmental variables were excluded from the modeling processes based on a correlation analysis to ensure predicted suitability.The predicted area was 790.09 km^(2),which is much larger than the known seagrass distribution in China(87.65 km^(2)).By 2100,the suitable habitat of seagrass will shift northwest and increase to 923.62 km2.Models of the sum of the individual family under-pre-dicted the national distribution of seagrasses and consistently showed a downward trend in the future.Out of all environmental vari-ables,physical parameters(e.g.,depth,land distance,and sea surface temperature)contributed the most in predicting seagrass distri-butions,and nutrients(e.g.,nitrate,phosphate)ranked among the key influential predictors for habitat suitability in our study area.This study is the first effort to fill a gap in understanding the distribution of seagrasses in China.Further studies using modeling and biological/ecological approaches are warranted.

关键词： seagrass meadows species distribution modeling global climate change Chinese coastal waters

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Effects of vibration conditions,spatial confinement and friction on mixing and segregation characteristics of mixed pebble beds for CFETR WCCB blanket

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Particuology 2024年第2期85卷 268-279页

作者： yong Liu Chongyang He Cong wang Lei chen Songlin Liu Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei230031China University of Science and Technology of China Hefei230027China chengdu University Chengdu610106China Zhejiang Lab Hangzhou310000China

This paper presents the study of the dynamic characteristics of confined mixed pebble beds with different friction under different vibration conditions using the discrete element method.Theλsegre-gation index is used to quantify the degree of particle mixing or segregation.The percolation,convection and diffusion mechanisms are responsible for the segregation patterns of the mixed pebble.The results show the degree of segregation can be suppressed by decreasing the vibration acceleration or free space height below a threshold.Further simulation reveals the threshold of vibration acceleration or free space height both are related to the bed height increment which determines the strength of the percolation mechanism.In addition,the strength of percolation and convection becomes weaker by decreasing the friction of particles and walls,which makes the pebbled bed remains in a mixed state under vibration.These findings are significant to clarify the main factors behind the three segregation mechanisms and hence provide solutions to retaining the mixed state of the Li2TiO3&Be12Ti mixed pebble bed.

关键词： Vibration Segregation Binary pebble bed Discrete element method

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Quantification of perfluorinated compounds in atmospheric particulate shows potential connection with environmental event

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Journal of Environmental Sciences 2024年第2期136卷 237-247页

作者： Hua Tang Ying wang Shengling Si Hongli Li David Da yong chen National Institute of Metrology 18 BeisanhuandongluChaoyang DistrictBeijing 100029China School of Chemistry and Materials Science Nanjing Normal UniversityNanjing 210023China Si Chuan Zhong Ce Biao Wu Technology Co.Ltd. Sichuan 610052China Department of Chemistry University of British ColumbiaVancouver V6T 1Z1BCCanada

A method of quantification of perfluorinated compounds(PFCs)from atmospheric particulate matter(APM)is described.A single step pretreatment method,selective pressurized liquid extraction(SPLE),was developed to reduce the high matrix background and avoid contamination from commonly used multiple sample pretreatment steps.An effective sorbent was selected to purify the PFCs during SPLE,followed by liquid chromatography-tandem mass spectrometry(LC–MS/MS),for quantification of PFCs.Conditions affecting the SPLE efficiency,including temperature,static extraction time,and number of extraction cycles used,were studied.The optimum conditions were found to be 120℃,10 min,and 3 cycles,respectively.LC-MS/MS method was developed to obtain the optimal sensitivity specific to PFCs.The method detection limits(MDLs)were 0.006 to 0.48 ng/g for the PFCs studied and the linear response range was from 0.1 to 100 ng/g.To ensure accurate values were obtained,each step of the experiment was evaluated and controlled to prevent contamination.The optimized method was tested by performing spiking experiments in natural particulate matter matrices and good rates of recovery and reproducibility were obtained for all target compounds.Finally,the method was successfully used to measure 16 PFCs in the APM samples collected in Beijing over five years from 2015 to 2019.It is observed that some PFCs follow the trend of total PFC changes,and can be attributed to the environment influencing events and policy enforcement,while others don't seem to change as much with time of the year or from year to year.

关键词： Selective pressurized liquid extraction Liquid chromatography-mass spectrometry Perfluorinated compounds Atmospheric particulate matter Pollution control

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Towards sparse matrix operations:graph database approach for power grid computation

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Global Energy Interconnection 2023年第1期6卷 50-63页

作者： Daoxing Li Kai Xiao Xiaohui wang Pengtian Guo yong chen China Electric Power Research Institute Co.Ltd. Beijing 100192P.R.China

The construction of new power systems presents higher requirements for the Power Internet of Things(PIoT)technology.The“source-grid-load-storage”architecture of a new power system requires PIoT to have a stronger multi-source heterogeneous data fusion ability.Native graph databases have great advantages in dealing with multi-source heterogeneous data,which make them suitable for an increasing number of analytical computing tasks.However,only few existing graph database products have native support for matrix operation-related interfaces or functions,resulting in low efficiency when handling matrix calculations that are commonly encountered in power grids.In this paper,the matrix computation process is expressed by a strategy called graph description,which relies on the natural connection between the matrix and structure of the graph.Based on that,we implement matrix operations on graph database,including matrix multiplication,matrix decomposition,etc.Specifically,only the nodes relevant to the computation and their neighbors are concerned in the process,which prunes the influence of zero elements in the matrix and avoids useless iterations compared to the conventional matrix computation.Based on the graph description,a series of power grid computations can be implemented on graph database,which reduces redundant data import and export operations while leveraging the parallel computing capability of graph database.It promotes the efficiency of PIoT when handling multi-source heterogeneous data.An comprehensive experimental study over two different scale power system datasets compares the proposed method with Python and MATLAB baselines.The results reveal the superior performance of our proposed method in both power flow and N-1 contingency computations.

关键词： Graph database Graph description Matrix Parallel computing Power flow

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The Research for Surface Properties of Steel Slag Powder and High-Temperature Rheological Properties of Asphalt Mortar

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Journal of Wuhan University of Technology(Materials Science) 2023年第5期38卷 1096-1104页

作者： wang Yefei YUAN Yan YANG Lihong LIU yong chen Yiwen College of Civil Engineering Fuzhou UniversityFuzhou 350108China Fujian Road&Bridge Construction Co. LtdFuzhou 350108China

In order to evaluate the feasibility of steel slag powder as filler,the coating properties of steel slag and limestone aggregate were compared by water boiling test,the micro morphology difierences between steel slag powder and mineral powder(limestone powder)were compared by scanning electron microscope(SEM),and the high-temperature rheological properties of asphalt mortar with difierent ratio of filler quality to asphalt quality(F/A)and difierent substitution rates of mineral powder(S/F)were studied by dynamic shear rheological test.The results show that the surface microstructure of steel slag powder is more abundant than that of mineral powder,and the adhesion of steel slag to asphalt is better than that of limestone.At the same temperature,the lower the ratio of S/F is,the greater the rutting factor and complex modulus will be.In addition,the complex modulus and rutting factor of the asphalt mortar increase with the increase of F/A,and the filler type and F/A have a negligible efiect on the phase angle.

关键词： steel slag powder asphalt mortar microcosmic adhesion high-temperature rheological properties

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A new genus and species of disc-bearing Labeoninae(Teleostei:Cypriniformes)from Guangxi,China

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Zoological Research 2022年第3期43卷 409-412页

作者： Zhi-Bang wang Xiao-yong chen Lan-Ping Zheng School of Chinese Materia Medica Yunnan University of Chinese MedicineKunmingYunnan 650500China Southeast Asia Biodiversity Research Institute Chinese Academy of SciencesYezinNay Pyi Taw 05282Myanmar Kunming Institute of Zoology Chinese Academy of SciencesKunmingYunnan 650223China University of Chinese Academy of Sciences Beijing 100049China

DEAR EDITOR,Guigarra cailaoensis sp.nov.,a new genus and species of Labeoninae,was collected from Guangxi Zhuang Autonomous Region,China.It differs from all other genera within Labeoninae by a unique combination of the following characters:(1)rostral cap smooth with posterior margin slightly serrated;(2)upper lip well developed and covering most of upper jaw;(3)gular disc present with crescentic torus.

关键词： slightly China. torus

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A 124 dB dynamic range sigma-delta modulator applied to non-invasive EEG acquisition using chopper-modulated input-scaling-down technique

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Science China(Information Sciences) 2022年第4期65卷 23-37页

作者： Kaiquan chen Mingyi chen Longlong chenG Liang QI Guoxing wang yong LIAN Department of Micro/Nano Electronics Shanghai Jiao Tong University China Electronic Cloud Brain (Tianjin) Technology Co. Ltd.

With the advancement of brain science in recent years, the non-invasive brain-computer interfaces（BCIs） based on electroencephalogram（EEG） acquisition have been widely adopted in various brain-inspired applications. The acquisition of multi-channel microvolts EEG signals corrupted by the motion artifacts（MAs） of up to several volts poses enormous challenges to the design of analog front-end（AFE）, especially the analog-to-digital converter（ADC）, which is necessary to achieve low noise, wide dynamic range（DR）,high accuracy as well as low power. In this paper, a wide DR Σ△ modulator with chopper-modulated inputscaling-down（CM-ISD） technique has been proposed to deal with large input offset while extending dynamic range. Fabricated in 180 nm CMOS technology, the prototype occupies a core area of 0.32 mm;. With a 40 Hz input signal and 125 Hz Nyquist bandwidth, the measured signal-to-noise ratio（SNR） and signalto-noise and distortion ratio（SNDR） are 117 and 110 dB, respectively. Thanks to the proposed CM-ISD technique, the modulator is capable of withstanding a full-scale(4.5 V;) input whereas the measured DR has been extended from 99 to 124 dB. The power consumption is 2.75 mW under 5 V supply voltage,corresponding to 170.6 dB Schreier figure-of-merit（FoMS）. The multi-channel EEG acquisition has been demonstrated based on the proposed modulator, showing its potential in advanced non-invasive BCI systems.

关键词： Analog-to-digital converter (ADC) ΣΔ modulator brain computer interface electroencephalogram dynamic range motion artifacts

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Global Energy Interconnection 2023年第1期6卷 15-25页

作者： Kai Xiao Daoxing Li Pengtian Guo Xiaohui wang yong chen China Electric Power Research Institute Co.Ltd. Beijing 100192P.R.China

Operation control of power systems has become challenging with an increase in the scale and complexity of power distribution systems and extensive access to renewable energy.Therefore,improvement of the ability of data-driven operation management,intelligent analysis,and mining is urgently required.To investigate and explore similar regularities of the historical operating section of the power distribution system and assist the power grid in obtaining high-value historical operation,maintenance experience,and knowledge by rule and line,a neural information retrieval model with an attention mechanism is proposed based on graph data computing technology.Based on the processing flow of the operating data of the power distribution system,a technical framework of neural information retrieval is established.Combined with the natural graph characteristics of the power distribution system,a unified graph data structure and a data fusion method of data access,data complement,and multi-source data are constructed.Further,a graph node feature-embedding representation learning algorithm and a neural information retrieval algorithm model are constructed.The neural information retrieval algorithm model is trained and tested using the generated graph node feature representation vector set.The model is verified on the operating section of the power distribution system of a provincial grid area.The results show that the proposed method demonstrates high accuracy in the similarity matching of historical operation characteristics and effectively supports intelligent fault diagnosis and elimination in power distribution systems.

关键词： Neural information retrieval Power distribution Graph data Operating section Similarity matching

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The Gray Mold Spore Detection of Cucumber Based on Microscopic Image and Deep Learning

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Plant Phenomics 2023年第1期5卷 47-59页

作者： Kaiyu Li Xinyi Zhu chen Qiao Lingxian Zhang Wei Gao yong wang China Agricultural University Beijing100083China Key Laboratory of Agricultural Informationization Standardization Ministry of Agriculture and Rural AffairsBeijing100083China Tianjin Academy of Agricultural Sciences Institute of Plant ProtectionTianjin300384China

Rapid and accurate detection of pathogen spores is an important step to achieve early diagnosis of diseases in precision agriculture.Traditional detection methods are time-consuming,laborious,and subjective,and image processing methods mainly rely on manually designed features that are difficult to cope with pathogen spore detection in complex scenes.Therefore,an MG-YOLO detection algorithm(Multi-head self-attention and Ghost-optimized YOLO)is proposed to detect gray mold spores rapidly.Firstly,Multi-head self-attention is introduced in the backbone to capture the global information of the pathogen spores.Secondly,we combine weighted Bidirectional Feature Pyramid Network(BiFPN)to fuse multiscale features of different layers.Then,a lightweight network is used to construct GhostCSP to optimize the neck part.Cucumber gray mold spores are used as the study object.The experimental results show that the improved MG-YOLO model achieves an accuracy of 0.983 for detecting gray mold spores and takes 0.009 s per image,which is significantly better than the state-of-the-art model.The visualization of the detection results shows that MG-YOLO effectively solves the detection of spores in blurred,small targets,multimorphology,and high-density scenes.Meanwhile,compared with the YOLOv5 model,the detection accuracy of the improved model is improved by 6.8%.It can meet the demand for high-precision detection of spores and provides a novel method to enhance the objectivity of pathogen spore detection.

关键词： Ghost Deep image

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Numerical simulation of effect of various parameters on atomization in an annular slit atomizer

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Journal of Iron and Steel Research(International) 2023年第6期30卷 1128-1141页

作者： Yi wang Yi-chen Dang Xiao-qing chen Bao wang Zhong-qiu Liu Jian-an Zhou Chang-yong chen The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina

As the width-thickness ratio of the discrete nozzle atomizer’s discrete hole greatly influences the loss of atomizing gas flow rate,the discrete nozzle atomizer was transformed into an annular slit atomizer with the same total nozzle outlet area.A numerical simulation study on the effect of various parameters on the atomization in the annular slit atomizer was carried out by coupling both the large eddy simulation(LES)and volume of fluid(VOF)model,which is based on the applicability of LES in capturing the breakup behavior of transient liquid droplets and the advantage of VOF method in directly capturing the phase interface.The simulation results showed that the increase in the atomization pressure makes the gas gain higher momentum,while the increase in the nozzle intersection angle decreases the distance between the nozzle exit and the computational domain axis.The increase in these two variables results in enhancing the gas-liquid interaction in the primary atomization zone and the formation of more aluminum droplets simultaneously.It is considered that the atomization effect becomes better when atomization pressure is 2.5 MPa,and the nozzle intersection angle is 60°.Industrial tests showed that the aluminum powder prepared by the optimized annular slit atomizer has a finer mean particle size and a higher yield of fine powder.The numerical simulation results agree well with the industrial test data of the powder particle size.

关键词： Annular slit atomizer Volume of fluid model Atomization process Atomization pressure Nozzle intersection angle Atomization effect

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