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Impact of ocean data assimilation on the seasonal forecast of the 2014/15 marine heatwave in the Northeast Pacific Ocean

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Atmospheric and Oceanic Science Letters 2025年第1期18卷 24-31页

作者： Tiantian Tang Jiaying He Huihang Sun Jingjia Luo institute for Climate and application Research(ICAR)/Key Laboratory of Meteorological Disaster Nanjing University of Information Science and TechnologyNanjingChina

A remarkable marine heatwave,known as the“Blob”,occurred in the Northeast Pacific Ocean from late 2013 to early 2016,which displayed strong warm anomalies extending from the surface to a depth of 300 *** study employed two assimilation schemes based on the global Climate Forecast System of Nanjing University of Information Science(NUIST-CFS 1.0)to investigate the impact of ocean data assimilation on the seasonal prediction of this extreme marine *** sea surface temperature(SST)nudging scheme assimilates SST only,while the deterministic ensemble Kalman filter(EnKF)scheme assimilates observations from the surface to the deep *** latter notably improves the forecasting skill for subsurface temperature anomalies,especially at the depth of 100-300 m(the lower layer),outperforming the SST nudging *** excels in predicting both horizontal and vertical heat transport in the lower layer,contributing to improved forecasts of the lower-layer warming during the *** improvements stem from the assimilation of subsurface observational data,which are important in predicting the upper-ocean *** results suggest that assimilating ocean data with the EnKF scheme significantly enhances the accuracy in predicting subsurface temperature anomalies during the Blob and offers better understanding of its underlying mechanisms.

关键词： Seasonal forecast Ocean data assimilation Marine heatwave Subsurface temperature

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Modulated waveforms for harmonic minimization of far-field signals in amplitude-modulated heating of the ionosphere

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Earth and Planetary Physics 2025年第02期9卷 387-399页

作者： ZhiJian Lu Yong Li Hui Li Jian Wu JingFeng Yao XingBao Lyu ChengXun Yuan ZhongXiang Zhou Ying Wang School of Physics Harbin Institute of Technology China Research institute of Radio Waves Propagation Heilongjiang Provincial Key Laboratory of Plasma Physics and application technology Heilongjiang Provincial Innovation Research Center for Plasma Physics and application technology (International Cooperation)

This paper establishes an amplitude modulation heating model, simulating the far-field radiation of ELF/VLF signals generated by modulation heating, as well as the specific location and longitudinal extent of the radiation source. We consider various modulation waveforms and find that square-wave modulation has the highest excitation efficiency for ELF/VLF signals, and that square-wave modulation with a smaller duty cycle(<50%) exhibits higher excitation efficiency for ELF/VLF signals, while the sin2t waveform modulation yields the lowest proportion of harmonic energy in the generated signals. The amplitude of the second harmonic generated by the sin2t waveform is less than one-tenth that of the fundamental frequency, and the energy of higher-frequency harmonics can be negligibly small compared with those of the fundamental wave. It is a challenging task to achieve a balance between enhancing the excitation efficiency of ELF/VLF signals and also suppressing harmonics generated by the modulated heating process. This is because the harmonics are correspondingly enhanced as the excitation efficiency of the signals is increased. However, we find that under conditions of varying effective radiant power and modulation frequency, as long as the modulation waveform is unchanged, the energy ratio between the fundamental frequency signal generated by modulated heating and each harmonic is relatively fixed, with changes only in signal intensity and the location of the radiation source zone. This implies that one can first select modulation waveforms that make the signal less prone to distortion, then increase the effective radiated power to enhance the signal strength, without concern for harmonic interference of the fundamental signal.

关键词： ELF/VLF harmonic amplitude-modulated heating modulated waveforms

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Spatial-temporal distribution and emission of urban scale air pollutants in Hefei based on Mobile-DOAS

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Journal of Environmental Sciences 2025年第5期151卷 238-251页

作者： Zhidong Zhang Pinhua Xie Ang Li Min Qin Jin Xu Zhaokun Hu Xin Tian Feng Hu Yinsheng Lv Jiangyi Zheng Youtao Li School of Environmental Science and Optoelectronic technology University of Science and Technology of ChinaHefei 230026China Key Laboratory of Environmental optics and technology Anhui Institute of Optics and Fine MechanicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Chinese Academy of Sciences Beijing 100049China Information Materials and Intelligent Sensing Laboratory of Anhui Province Institutes of Physical Science and Information TechnologyAnhui UniversityHefei 230601China

As a significant city in the Yangtze River Delta regions,Hefei has experienced rapid changes in the sources of air pollution due to its high-speed economic development and urban ***,there has been limited research in recent years on the spatial-temporal distribution and emission of its atmospheric *** address this,this study conducted mobile observations of urban roads using the Mobile-DOAS instrument from June 2021 to May *** monitoring results exhibit a favourable consistent with TROPOMI satellite data and ground monitoring station ***,there were pronounced seasonal variations in air ***,high concentration of HCHO and NO_(2)were closely associated with traffic congestion on roadways,while heightened SO_(2)levels were attributed to winter heating and industrial *** study also revealed that with the implementation of road policies,the average vehicle speed increased by 95.4%,while the NO concentration decreased by 54.4%.In the estimation of urban NO_(x)emission flux,it was observed that in temporal terms,compared with inventory data,the emissions calculated viamobile measurements exhibitedmore distinct seasonal patterns,with the highest emission rate of 349 g/sec in winter and the lowest of 142 g/sec in *** spatial terms,the significant difference in emissions between the inner and outer ring roads also suggests the presence of the city’s primary NO_(x)emission sources in the area between these two *** study offers data support for formulating the next phase of air pollution control measures in urban areas.

关键词： Mobile-DOAS HCHO NO_(2) SO_(2) Spatial-temporal distribution NOx emission

Optimization of transverse unidirectional scattering by morphology modification of irregular V-shaped silicon nanoantennas

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Optoelectronics Letters 2025年第3期21卷 129-135页

作者： ZENG Ming ZHAO Feng WANG Xianghui School of Electrical and Information Engineering Tianjin University institute of Modern optics Tianjin Key Laboratory of Micro-scale Optical Information Science and TechnologyNankai University

A scheme based on irregular V-shaped silicon nanoantennas is proposed to optimize transverse unidirectional scattering under plane wave irradiation. Traditional methods of designing regular shapes offer fewer parameters and higher search efficiency. However, due to the limitations of regular shapes, it is challenging to meet high-precision design requirements. Irregular shape design allows for a broader range of adjustments, but the complexity of shape parameters leads to lower search efficiency and a higher likelihood of converging to local optima.

关键词： A

Development of a net ozone production rate detection system based on dual-channel cavity ring-down spectroscopy

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Journal of Environmental Sciences 2025年第3期149卷 419-430页

作者： Jinzhao Tong Renzhi Hu Changjin Hu Xiaoyan Liu Haotian Cai Chuan Lin Liujun Zhong JiaweiWang Pinhua Xie School of Environmental Science and Optoelectronic technology University of Science and Technology of ChinaHefei 230026China Anhui institute of optics and Fine Mechanics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China School of Pharmacy Anhui Medical UniversityHefei 230032China

A novel system for measuring net photochemical ozone production rates in the atmosphere based on cavity ring-down spectroscopy(OPR-CRDS)was *** system consists of two chambers(a reaction chamber and a reference chamber)and a dual-channel O_(x)-CRDS *** minimize the wall loss of O_(x)in the chambers,the inner surfaces of both chambers are coated with Teflon *** performance of the OPR-CRDS system was *** was found that even though the photolysis frequency(J value)decreased by 10%,the decrease in the P(O_(3))caused by the ultraviolet-blocking film coating was less than 3%.The two chambers had a good consistency in the mean residence time and the measurement of NO_(2)and O_(x)under the condition of no *** detection limit of the OPR-CRDS was determined to be 0.20 ppbv/*** further verify the accuracy of the system,the direct measurement values of the OPR-CRDS systemwere comparedwith the calculation results based on radical(OH,HO_(2),and RO_(2))reactions,and a good correlation was obtained between the measured and calculated ***,the developed instrument was applied to obtain the comprehensive field observations at an urban site in the Yangtze River Delta(China)for 40 days,the time series and change characteristics of the P(O_(3))were obtained directly,and the good environmental adaptability and stability of the OPR-CRDS system were *** is expected that the new instrument will be beneficial to investigations of the relationship between P(O_(3))and its precursors.

关键词： Ozone Net photochemical production rate CRDS Atmospheric chemistry

MAX-DOAS observations of pollutant distribution and transboundary transport in typical regions of China

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Journal of Environmental Sciences 2025年第5期151卷 652-666页

作者： Hongmei Ren Ang Li Zhaokun Hu Hairong Zhang Jiangman Xu Xinyan Yang Jinji Ma Shuai Wang School of Physics and Electronic Information Anhui Normal UniversityWuhu 241000China Key Laboratory of Environmental optics and technology Anhui Institute of Optics and Fine MechanicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and technology of China Hefei 230026China School of Geography and Tourism Anhui Normal UniversityWuhu 241000China China National Environmental Monitoring Centre Beijing 100012China

Studying the spatiotemporal distribution and transboundary transport of aerosols,NO_(2),SO_(2),and HCHO in typical regions is crucial for understanding regional pollution *** a 2-year study using multi-axis differential optical absorption spectroscopy in Qingdao,Shanghai,Xi’an,and Kunming,we investigated pollutant distribution and transport across Eastern China-Ocean,Tibetan Plateau-Central and Eastern China,and China-Southeast Asia ***,pollutant distributionwas ***,frequently clouded and misty,exhibited consistently high aerosol optical depth throughout the *** Qingdao and Shanghai,NO_(2)and SO_(2),as well as SO_(2)in Xi’an,increased in *** HCHO in summer in Shanghai and Xi’an,especially Xi’an,suggests potential ozone pollution ***,pollutant transportation across interfaces was *** the Eastern China-Ocean interface,the gas transport flux was the largest among other interfaces,with the outflux exceeding the influx,especially in winter and *** input of pollutants from the Tibetan Plateau to central-eastern Chinawas larger than the output in winter and spring,with SO_(2)having the highest transport flux in *** pollution input from Southeast Asia to China significantly exceeded the output,with spring and winter inputs being 3.22 and 3.03 times the output,***,the transportation characteristics of a pollution event at Kunming were *** this period,pollutants were transported from west to east,with themaximum SO_(2)transport flux at an altitude of 2.87 km equaling 27.74μg/(m^(2)·s).It is speculated that this pollution was caused by the transport from Southeast Asian countries to Kunming.

关键词： Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) Pollutants Spatiotemporal distribution Transboundary transport

Improving the Seasonal Forecast of Summer Precipitation in Southeastern China Using a CycleGAN-based Deep Learning Bias Correction Method

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Advances in Atmospheric Sciences 2025年第1期42卷 26-35页

作者： Song YANG Fenghua LING Jing-Jia LUO Lei BAI institute of Climate application Research(ICAR)/School of Future technology/CIC-FEMD/KLME/ILCEC Nanjing University of Information Science and TechnologyNanjing 210044China Shanghai Artificial Intelligence Laboratory Shanghai 200232China

Accurate seasonal precipitation forecasts,especially for extreme events,are crucial to preventing meteorological hazards and their potential impacts on national development,social activity,and ***,the intensity of summer precipitation is often largely underestimated in many current dynamic *** study uses a deep learning method called Cycle-Consistent Generative Adversarial Networks(CycleGAN)to improve the seasonal forecasts for June-JulyAugust precipitation in southeastern China by the Nanjing University of Information Science and technology Climate Forecast System(NUIST-CFS 1.0).The results suggest that the CycleGAN-based model significantly improves the accuracy in predicting the spatiotemporal distribution of summer precipitation compared to the traditional quantile mapping(QM)*** the unpaired bias-correction model,we can also obtain advanced forecasts of the frequency,intensity,and duration of extreme precipitation events over the dynamic model *** study expands the potential applications of deep learning models toward improving seasonal precipitation forecasts.

关键词： bias correction CycleGAN QM NUIST-CFS 1.0 extreme precipitation

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Design and testing research of LiDAR for detecting atmospheric turbulence

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Optoelectronics Letters 2025年第3期21卷 172-176页

作者： QIU Duoyang LI Xianyang YANG Hao ZHU Xiaomeng FANG Zhiyuan XU Xiang School of Advanced Manufacturing Engineering Hefei University Anhui Provincial Engineering technology Research Center of Intelligent Vehicle Control and Integrated Design technology Hefei University Science Island Branch of Graduate School University of Science and Technology of China School of Mechanical and Energy Engineering Ningbo Tech University Key Laboratory of Atmospheric optics Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences

Atmospheric turbulence is an important parameter affecting laser atmospheric transmission. This paper reports on a self-developed atmospheric turbulence detection Li DAR system (scanning differential image motion Li DAR(DIM-Li DAR) system). By designing and simulating the optical system of atmospheric turbulence detection Li DAR,the basic optical imaging accuracy has been determined.

关键词： A

Free vibration and transient response of double curved beams connected by intermediate straight beams

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 37-62页

作者： R.A.JAFARI-TALOOKOLAEI H.GHANDVAR E.JUMAEV S.KHATIR T.CUONG-LE School of Mechanical Engineering Babol Noshirvani University of Technology Department of Mechanical Engineering Faculty of Engineering New Uzbekistan University University of Business and Science Center for Engineering application and technology Solutions Ho Chi Minh City Open University

This paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FGP) materials. The strain potential and kinetic energies of each beam along with the work done by the external force are calculated. Additionally, a higher-order beam element is introduced to derive stiffness and mass matrices, along with the force vector. The curved and straight beams are discretized, and their assembled stiffness, mass matrices, and force vectors, are *** conditions at the joints are used to derive the total matrices of the entire structure. Subsequently, the natural frequencies and transient response of the system are determined. The accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial software ANSYS, demonstrating excellent ***, a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and transient response of the considered structure.

关键词： double curved beam finite element method functionally graded porous (FGP) material intermediate straight beam O313 vibration analysis