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Investigation of formaldehyde sources and its relative emission intensity in shipping channel environment

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Journal of Environmental Sciences 2024年第8期142卷 142-154页

作者： Jiaqi Liu Shanshan Wang Yan Zhang Yuhao Yan Jian Zhu Sanbao Zhang Tianyu Wang Yibing Tan Bin Zhou Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention(LAP3) Department of Environmental Science and EngineeringFudan UniversityShanghai 200433China institute of Eco-Chongming(IEC) No.20 Cuiniao RoadShanghai 202162China institute of Atmospheric Sciences Fudan UniversityShanghai 200433China National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary Fudan UniversityShanghai 200438China institute of Digitalized Sustainable Transformation Big Data InstituteFudan UniversityShanghai 200433China

Formaldehyde(HCHO)is considered one of the most abundant gas-phase carbonyl compounds in the atmosphere,which can be directly emitted through transportation ***-Path Differential Optical Absorption Spectroscopy(LP-DOAS)was used to observe HCHO in the river channel of Wusong Wharf in Shanghai,China for the whole year of *** to the impact of ship activity,the annual average HCHO level in the channel is about2.5 times higher than that in the nearby campus *** explain the sources of HCHO under different meteorological conditions,the tracer-pair of CO and O_(x)(NO_(2)+O_(3))was used on the clustered air *** results of the source appointment show that primary,secondary and background account for 24.14%(3.34±1.19 ppbv),44.78%(6.20±2.04ppbv)and 31.09%(4.31±2.33 ppbv)of the HCHO in the channel when the air masses were from the mixed direction of the city and channel,*** performing background station subtraction at times of high primary HCHO values and resolving the plume peaks,directly emitted HCHO/NO_(2)in the channel environment and plume were determined to be mainly distributed between 0.2 and *** cargo ships with higher sailing speeds or main engine powers tend to have higher HCHO/NO_(2)*** the knowledge of NO_(2)(or NO_(x))emission levels from ships,this study may provide data support for the establishment of HCHO emission factors.

关键词： HCHO LP-DOAS Channel environment Ship emissions

Variational Neural Inference Enhanced Text Semantic Communication System

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China Communications 2024年第7期21卷 50-64页

作者： Zhang Xi Zhang Yiqian Li Congduan Ma Xiao School of Electronics and Communication Engineering Sun Yat-Sen UniversityShenzhen 518107China Guizhou University State Key Laboratory of public big data Guiyang 550025China Shenzhen Key Laboratory of Navigation and Communication Integration Shenzhen 518107China School of Computer Science and Engineering Sun Yat-Sen UniversityGuangzhou 510006China

Recently,deep learning-based semantic communication has garnered widespread attention,with numerous systems designed for transmitting diverse data sources,including text,image,and speech,*** efforts have been directed toward improving system performance,many studies have concentrated on enhancing the structure of the encoder and ***,this often overlooks the resulting increase in model complexity,imposing additional storage and computational burdens on smart ***,existing work tends to prioritize explicit semantics,neglecting the potential of implicit *** paper aims to easily and effectively enhance the receiver's decoding capability without modifying the encoder and decoder *** propose a novel semantic communication system with variational neural inference for text ***,we introduce a simple but effective variational neural inferer at the receiver to infer the latent semantic information within the received *** information is then utilized to assist in the decoding *** simulation results show a significant enhancement in system performance and improved robustness.

关键词： deep learning semantic communication variational neural inference

Machine Learning for Signal Demodulation in Underwater Wireless Optical Communications

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China Communications 2024年第5期21卷 297-313页

作者： Ma Shuai Yang Lei Ding Wanying Li Hang Zhang Zhongdan Xu Jing Li Zongyan Xu Gang Li Shiyin Department of Strategic and Advanced Interdisciplinary Research Peng Cheng LaboratoryShenzhen 518055China School of Information and Control Engineering China University of Mining and TechnologyXuzhou 221116China data-driven Intelligent Information System Laboratory Shenzhen Research Institute of Big DataShenzhen 518172China Ocean College Zhejiang UniversityZhoushan 316021China State Key Laboratory of Millimeter Waves Southeast UniversityNanjing 210096China

The underwater wireless optical communication(UWOC)system has gradually become essential to underwater wireless communication *** other existing works on UWOC systems,this paper evaluates the proposed machine learningbased signal demodulation methods through the selfbuilt experimental *** on such a platform,we first construct a real signal dataset with ten modulation ***,we propose a deep belief network(DBN)-based demodulator for feature extraction and multi-class feature *** also design an adaptive boosting(Ada Boost)demodulator as an alternative scheme without feature filtering for multiple modulated ***,it is demonstrated by extensive experimental results that the Ada Boost demodulator significantly outperforms the other *** also reveals that the demodulator accuracy decreases as the modulation order increases for a fixed received optical power.A higher-order modulation may achieve a higher effective transmission rate when the signal-to-noise ratio(SNR)is higher.

关键词： AdaBoost DBN machine learning signal demodulation

SDGSAT-1: Capabilities for Monitoring and Evaluating SDG Indicators

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空间科学学报 2024年第4期44卷 677-686页

作者： GUO Huadong DOU Changyong LIANG Dong JIANG Nijun TANG Yunwei MA Wenyong International Research Center for big data for Sustainable Development Beijing 100094 Key Laboratory of Digital Earth Science Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100094 University of Chinese Academy of Sciences Beijing 100049

SDGSAT-1,the world's first science satellite dedicated to assisting the United Nations 2030 Sustainable Development Agenda,has been operational for over two and a half *** provides valuable data to aid in implementing the Sustainable Development Goals *** its Open Science Program,the satellite has maintained consistent operations and delivered free data to scientific and technological users from 88 *** program has produced a wealth of scientific output,with 72 papers,including 28 on data processing methods and 44 on applications for monitoring progress toward SDGs related to sustainable cities,clean energy,life underwater,climate action,and clean water and ***-1 is equipped with three key instruments:a multispectral imager,a thermal infrared spectrometer,and a glimmer imager,which have enabled ground-breaking research in a variety of domains such as water quality analysis,identification of industrial heat sources,assessment of environmental disaster impacts,and detection of forest *** precise measurements and ongoing monitoring made possible by this invaluable data significantly advance our understanding of various environmental *** are essential for making well-informed decisions on a local and global *** its application to academic research,SDGSAT-1 promotes global cooperation and strengthens developing countries'capacity to accomplish their sustainable development *** the satellite continues to gather and distribute data,it plays a pivotal role in developing strategies for environmental protection,disaster management and relief,and resource *** initiatives highlight the satellite's vital role in fostering international collaboration and technical innovation to advance scientific knowledge and promote a sustainable future.

关键词： SDGSAT-1 Earth observation Remote sensing SDGs

DynIcedata:a gridded ice-water classification dataset at short-time intervals based on observations from multiple satellites over the marginal ice zone

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big Earth data 2024年第2期8卷 249-273页

作者： Lin Huang Yubao Qiu Yang Li Shuwen Yu Wanyang Zhong Changyong Dou Key Laboratory of Digital Earth Science Aerospace Information Research InstituteChinese Academy of SciencesBeijingChina International Research Center of big data for Sustainable Development Goals BeijingChina University of Chinese Academy of Sciences BeijingChina School of Resources and Geosciences China University of Mining and TechnologyXuzhouChina

High-resolution observations of short-term changes in sea ice are critical to understanding ice dynamics and also provide important information used in advice to shipping,especially in the *** individual satellite sensors provide periodic sea ice obser-vations with spatial resolutions of tens of meters,information regarding changes that occur over short time intervals of minutes or hours is *** this study,a gridded ice-water classification dataset with a high temporal resolution was developed based on observations acquired by multiple satellite sensors in the Marginal Ice Zone(MIZ).This dataset-DynIcedata-which combines Sentinel-1 Synthetic Aperture Radar(SAR)data with Gaofen-3(GF-3)SAR and SDGSAT-1 thermal infrared imagery was used to obtain observations of the MIZ with a range of temporal resolutions ran-ging from minutes to tens of *** areas of the Arctic covered include the Kara Sea,Beaufort Sea,and Greenland Sea during the period from August 2021 to August ***-oriented segmen-tation and thresholding were used to obtain the ice-water classifi-cation map from Sentinel-1 and GF-3 SAR image pairs and Sentinel-1 SAR and SDGSAT-1 thermal image *** time interval between the images in each pair ranged from 1 minute to 68 ***-kilometer grid sample granules with a spatial resolution of 25 m for the GF-3 SAR data and 30 m for the SDGSAT-1 thermal data were *** classification was verified as having an overall accuracy of at least 95.58%.The DynIcedata dataset consists of 7338 samples,which could be used as reference data for further research on rapid changes in sea ice patterns at different short time scales and provide support for research on thermodynamic and dynamic models of sea ice in combination with other environmen-tal data,thus potentially improving the accuracy of sea ice forecast-ing using Artificial *** dataset can be accessed at https://***/10.57760/sciencedb.j00001.00784.

关键词： Sea ice dynamics ice-water classification GF-3 SDGSAT-1 marginal ice zone

SPARSE RECOVERY BASED ON THE GENERALIZED ERROR FUNCTION

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Journal of Computational Mathematics 2024年第3期42卷 679-704页

作者： Zhiyong Zhou Department of Statistics and data Science and Institute of Digital FinanceHangzhou City UniversityHangzhou 310015China

In this paper,we offer a new sparse recovery strategy based on the generalized error *** introduced penalty function involves both the shape and the scale parameters,making it extremely *** both constrained and unconstrained models,the theoretical analysis results in terms of the null space property,the spherical section property and the restricted invertibility factor are *** practical algorithms via both the iteratively reweighted■_(1)and the difference of convex functions algorithms are *** experiments are carried out to demonstrate the benefits of the suggested approach in a variety of *** practical application in magnetic resonance imaging(MRI)reconstruction is also investigated.

关键词： Sparse recovery Generalized error function Nonconvex regularization Itera-tive reweighted Li Difference of convex functions algorithms

A study of U-isotope ground state properties with covariant energy density functional

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Chinese Physics C 2024年第6期48卷 130-135页

作者：王俊辰田源续瑞瑞崔莹陶曦孙小东张智张玥韩银录葛智刚舒能川 China Nuclear data Center China Institute of Atomic EnergyBeijing 102413China China institute of Atomic Energy Beijing 102413China

In this study,we systematically analyzed the ground state of uranium isotopes from 225 to *** our calculations,we used the covariant energy density functional of density-dependent meson exchange interaction(DDME2)with separable pairing interaction(TMR).Using the multiple deformation constraint,we calculated the potential energy surface(PES)of the uranium isotopes for both even-even and even-odd nuclei with quadrupole and octupole *** on our calculation and upon comparing the experimental data and Hartree-Fock-Bogoliubov calculations with Gogny D1S calculation data,the ground state of uranium isotopes with reflection-asymmetric deformation was found to be preferred.

关键词： relativistic mean field density functional theory octupole deformation

Epistasis-aware genome-wide association studies provide insights into the efficient breeding of high-yield and high-quality rice

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Journal of Integrative Agriculture 2024年第8期23卷 2541-2556页

作者： Xiaogang He Zirong Li Sicheng Guo Xingfei Zheng Chunhai Liu Zijie Liu Yongxin Li Zheming Yuan Lanzhi Li Hunan Engineering&Technology Research Center for Agricultural big data Analysis&Decision-making/College of Plant Protection Hunan Agricultural UniversityChangsha 410128China Hubei Key Laboratory of Food Crop Germplasm and Genetic Improvement/Food Crop institute Hubei Academy of Agricultural SciencesWuhan 430064China

Marker-assisted selection(MAS)and genomic selection(GS)breeding have greatly improved the efficiency of rice *** to the influences of epistasis and gene pleiotropy,ensuring the actual breeding effect of MAS and GS is still a difficult challenge to *** this study,113 indica rice varieties(V)and their 565 testcross hybrids(TC)were used as the materials to investigate the genetic basis of 12 quality traits and nine agronomic *** original traits and general combining ability of the parents,as well as the original traits and midparent heterosis of TC,were subjected to genome-wide association *** total,381 primary significantly associated loci(SAL)and 1,759 secondary SALs that had epistatic interactions with these primary SALs were *** these loci,322 candidate genes located within or nearby the SALs were screened,204 of which were cloned genes.A total of 39 MAS molecular modules that are beneficial for trait improvement were identified by pyramiding the superior haplotypes of candidate genes and desirable epistatic alleles of the secondary *** the SALs were used to construct genetic networks,in which 91 pleiotropic loci were ***,we estimated the accuracy of genomic prediction in the parent V and TC by incorporating either no SALs,primary SALs,secondary SALs or epistatic effect SALs as *** the prediction accuracies of the four models were generally not significantly different in the TC dataset,the incorporation of primary SALs,secondary SALs,and epistatic effect SALs significantly improved the prediction accuracies of 5(26%),3(16%),and 11(58%)traits in the V dataset,*** results suggested that SALs and epistatic effect SALs identified based on an additive genotype can provide considerable predictive power for the parental *** also provide insights into the genetic basis of complex traits and valuable information for molecular breeding in rice.

关键词： rice genome-wide association study epistasis gene pleiotropy maker-associated selection genome selection

Study on the force chain characteristics with coal dust layer and the three-body contact stiffness

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Particuology 2024年第9期92卷 288-304页

作者： Xinwei Yang Dongxuan Wu Hongyue Chen Dong Wang School of Mechanical Engineering Liaoning Technical UniversityFuxin123000China Ordos institute of Liaoning Technical University Ordos017000China School of Mining Liaoning Technical UniversityFuxin123000China China National Coal Association Dynamic Research for High-end Complete Integrated Coal Mining Equipment and Big Data Analysis CentreFuxin123000China

To explore the influence of the meso-mechanical behaviors of the wet coal dust layers on the contact stiffness of mechanical bonding surfaces,a three-body contact model incorporating an interface with wet coal dust was constructed based on breakage *** model considered the mechanical surface morphology and contact characteristics of the wet coal *** force chain evolution laws of the wet coal dust layer were elucidated under the effects of gap filling and the cover layer,and the bearing characteristics of the three-body contact bonding surfaces were revealed by quantitative analyses of the number,length,collimation coefficient,and coordination number of the force chains within the wet coal dust ***,the three-body normal contact stiffness under various preload forces was computed and experimentally *** results demonstrate that the external load transfer path of the three-body contact bonding surfaces was from mechanical surface(macroscopic stress)to wet coal dust layer(mesoscopic force chains)and then to mechanical surface(peaks and valleys).The interactions among these three elements contributed to transforming the distributions of the macroscopic stresses and mesoscopic force chains to the locations at the peaks and valleys of the mechanical *** them,the proportion of short force chains in the wet coal dust layer increased from approximately 0.8%–91%,while the proportion of long force chains exhibited an opposite changing *** force chain collimation coefficient initially increased and subsequently stabilized,reaching a maximum value of 0.93.A large number of broken,small particles in the wet coal dust layer mainly served to fill the gaps among large *** maximum relative error between the experimental and simulated values on the three-body contact stiffness is 7.26%,indicating that the simulation results can be an approximate substitute for the experimental results with a certain degree of accuracy and practic

关键词： Wet coal dust Force chain Three-body contact stiffness Gap flling effect Cover layer effect