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NASTCNN: a spatio-temporal convolutional neural network with non-local attention mechanism for image-induced brain activity pattern recognition

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Optoelectronics Letters 2025年

作者： TAN Xiangxin SHAO Mingxiong ZENG Ke GU Yue School of Computer Science and Engineering， Tianjin University of Technology Engineering research center of Learning-Based Intelligent system (Ministry of Education)， Tianjin University of Technology Krembil research Institute， University Health Network

Deciphering the brain’s visual processing mechanisms has always been a hot topic. Using neural signal patterns to predict the corresponding external visual stimuli is crucial in understanding the interaction of real visual scenes. There are some challenges in the study of image-induced brain activity pattern recognition based on electroencephalogram (EEG)， e.g. how to fully utilize the effective features of EEG signals to improve the classification， and how the frequency and the length of EEG effect the model performance. We design an experimental paradigm that minimizes the interaction between visual stimuli， and propose a spatio-temporal convolutional neural network with non-local attention mechanism (NASTCNN) for image-induced brain activity pattern recognition. The framework utilizes non-local feature extraction operations to realize global information interaction between EEG signals over long distances and enhance the feature expression of some important information. Our model achieves the best performance on both MNIST-EEG and ImageNet-EEG datasets. The classification results are 24.00% and 50.10% respectively， higher than the random probability. We also analyze the effects of different EEG frequency bands and time subsequences of different lengths on the classification performance and which brain regions are activated over time. The results show that when full frequency band and entire length sequence are selected， the classification result is optimal. The occipital region is essential for processing visual tasks， and the temporal region and some frontal regions also play important role in the later stage of visual decoding. This research can help us better understand the visual processing mechanism of the brain.

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Effect of the westward-propagating zonal wind anomaly on the initial development of quasi-biweekly oscillation over the South China Sea during early summer

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Atmospheric and Oceanic Science Letters 2017年第1期10卷 89-95页

作者： CHEN Guang-Hua WANG Xu center for monsoon system research Institute of Atmospheric PhysicsChinese Academy of Science

The characteristics of quasi-biweekly oscillation（QBWO） over the South China Sea during early summer are *** results demonstrate that QBWO convection and the meridional wind anomaly exhibit local variation,while the zonal wind anomaly displays zonal ***,emergence of the zonal wind anomaly precedes the enhancement of QBWO convection,suggesting the zonally propagating zonal wind anomaly may play a key role in initiating the development of QBWO *** of the convergence of moisture flux and divergence tendency indicate that QBWO convection is primarily modulated by eddy *** the contributing factors in the divergence tendency,the β effect associated with the zonally-propagating zonal wind anomaly makes an appropriate phase difference with the eddy divergence,which can contribute to the convergence tendency in the initial stage of *** a result,QBWO convection and the meridional wind anomaly are enhanced,thus facilitating the initial development of QBWO convection over the SCS during early summer.

关键词： Westward-propagating zonal wind quasi-biweekly oscillation South China Sea early summer

A primary study of the correlation between the net air-sea heat flux and the interannual variation of western North Pacific tropical cyclone track and intensity

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Acta Oceanologica Sinica 2011年第6期30卷 27-35页

作者： WU Liang WEN Zhiping HUANG Ronghui center for monsoon and Environment research/Department of Atmospheric Sciences Sun Yat-sen University Guangzhou 510275 China center for monsoon system research Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

A singular value decomposition （SVD） analysis is carried out to reveal the relationship between the interannual variation of track and intensity of the western North Pacific tropical cyclones （WNPTCs） in the tropical cyclone （TC） active season （July–November） and the global net air-sea heat flux （Q net ） in the preceding season （April–June）. For this purpose, a tropical cyclone track and intensity function （TIF） is defined by a combination of accumulated cyclone energy （ACE） index and a cyclone track density function. The SVD analysis reveals that the first mode is responsible for the positive correlation between the upward heat flux in the tropical central Pacific and the increased activity of western North Pacific （WNP） TIF, the second mode for the positive correlation between the upward heat flux in the North Indian Ocean and the northeastward track shift of WNPTCs and the third mode for the negative correlation between the upward heat flux in mid-latitude central Pacific and the northwest displacement of the WNP TC-active center. This suggests that Q net anomalies in some key regions have a substantial remote impact on the WNP TC activity.

关键词： tropical cyclone western North Pacific the net air-sea heat flux (Q net ) interannual variation

High-dose dexamethasone regulates microglial polarization via the GR/JAK1/STAT3 signaling pathway after traumatic brain injury

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Neural Regeneration research 2025年第9期20卷 2611-2623页

作者： Mengshi Yang Miao Bai Yuan Zhuang Shenghua Lu Qianqian Ge Hao Li Yu Deng Hongbin Wu Xiaojian Xu Fei Niu Xinlong Dong Bin Zhang Baiyun Liu Beijing Tiantan Hospital Capital Medical UniversityBeijingChina Department of Neurology The First Hospital of Tsinghua UniversityBeijingChina Department of Neurotrauma and Beijing Key Laboratory of Central Nervous system Injury Beijing Neurosurgical InstituteCapital Medical UniversityBeijingChina Department of Critical Care Medicine Beijing Tiantan HospitalCapital Medical UniversityBeijingChina center for Nerve Injury and Repair Beijing Institute of Brain DisordersChina National Clinical Research Center for Neurological DiseasesBeijingChina

Although microglial polarization and neuroinflammation are crucial cellular responses after traumatic brain injury,the fundamental regulatory and functional mechanisms remain insufficiently *** potent anti-inflammato ry agents,the use of glucoco rticoids in traumatic brain injury is still controversial,and their regulatory effects on microglial polarization are not yet *** the present study,we sought to determine whether exacerbation of traumatic brain injury caused by high-dose dexamethasone is related to its regulatory effects on microglial polarization and its mechanisms of *** vitro cultured BV2 cells and primary microglia and a controlled cortical impact mouse model were used to investigate the effects of dexamethasone on microglial ***,dexamethasone,RU486(a glucocorticoid receptor antagonist),and ruxolitinib(a Janus kinase 1 antagonist)were ***-sequencing data obtained from a C57BL/6 mouse model of traumatic brain injury were used to identify potential targets of *** Morris water maze,quantitative reverse transcription-polymerase chain reaction,western blotting,immunofluorescence and confocal microscopy analysis,and TUNEL,Nissl,and Golgi staining were performed to investigate our ***-throughput sequencing results showed that arginase 1,a marker of M2 microglia,was significantly downregulated in the dexamethasone group compared with the traumatic brain injury group at3 days post-traumatic brain *** dexamethasone inhibited M1 and M2 microglia,with a more pronounced inhibitory effect on M2microglia in vitro and in *** receptor plays an indispensable role in microglial polarization after dexamethasone treatment following traumatic brain ***,glucocorticoid receptor activation increased the number of apoptotic cells and neuronal death,and also decreased the density of dendritic spines.A possible downstream receptor signaling mechanism is th

关键词： apoptosis BV2 microglia dexamethasone glucocorticoid receptor glucocorticoids innate immune system microglial polarization neuroinflammation primary microglia traumatic brain injury

Efficient photocatalytic reduction of CO2 to formate by a molecular noble metal-free system

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Science China Chemistry 2025年第1期68卷 152-156页

作者： Lihua Zhang Lingjing Chen Huatian Shi Yue Wei Gui Chen Tai-Chu Lau School of Environment and Civil Engineering Research Center for Eco-environmental Engineering Dongguan University of Technology Department of Chemistry and Institute of Molecular Functional Materials City University of Hong Kong

Reducing CO2to carbon-neutral solar fuels can not only alleviate the energy demand but also mitigate the greenhouse *** present,developing an efficient non-noble metal photo/electrocatalytic system for converting CO2to a specific product beyond CO is still a big ***,we report a new cobalt complex bearing 2,2′-bi-1,10-phenanthroline ligand that can photocatalytically reduce CO2to formate （HCOO-）.Turnover number （TON） for HCOO-up to 677 with 99%selectivity can be achieved using organic dyes purpurin as photosensitizer and 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole （BIH） as sacrificial reductant in a CO2-saturated NMP/TEA （v/v,3:1） solution under visible light *** potential electrolysis at-1.41 V （***/Ag Cl） in the presence of 12 m M Et3NHBF4also produced HCOO-with Faradaic efficiency of 39%.Spectroscopic and electrochemical studies suggest that a[CoI-H]species is the key intermediate for CO2reduction.

关键词： photocatalysis noble metal-free CO2 reduction formate cobalt hydride

An Idealized Numerical Study of the Effects of Uniform Zonal Winds on Tropical Cyclogenesis

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Atmospheric and Oceanic Science Letters 2015年第6期8卷 345-351页

作者： CAO Xi center for monsoon system research Institute of Atmospheric Physics Chinese Academy of Sciences

The effect of uniform zonal winds on tropical cyclone(TC)genesis is examined on a beta plane using an idealized mesoscale *** simulation results show that uniform easterly and westerly flows are both favorable for TC ***,uniform easterly flows result in a faster TC genesis rate compared with uniform westerly *** is found that faster TC genesis is associated with greater surface heat fluxes and convection during the early *** superposition of uniform easterly flows and the beta effect results in greater surface heat fluxes and convection around the TC center compared with uniform westerly ***,TC genesis is closely associated with the size and intensity of a mid-level *** joint greater convection induced by the easterly flows and beta effect results in enhancement of the vertical temperature gradient,which is associated with the intensification of mid-level *** strong and compact mid-level circulation is more favorable for efficient conversion of latent heat energy to the kinetic energy of the lower-level cyclonic ***,uniform easterly flows are more favorable for TC genesis than uniform westerly flows.

关键词： uniform zonal winds tropical cyclogenesis idealize

Modulation of Western North Pacific Tropical Cyclone Genesis by Intraseasonal Oscillation of the ITCZ:A Statistical Analysis

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Advances in Atmospheric Sciences 2012年第4期29卷 744-754页

作者：曹西黄平陈光华陈文 center for monsoon system research Institute of Atmospheric PhysicsChinese Academy of Sciences Graduate University of Chinese Academy of Sciences

The present study investigates modulation of western North Pacific （WNP） tropical cyclone （TC） genesis in relation to different phases of the intraseasonal oscillation （ISO） of ITCZ convection during May to October in the period 1979 2008. The phases of the ITCZ ISO were determined based on 30-80-day filtered OLR anomalies averaged over the region （5°20′N, 120°150′E）. The number of TCs during the active phases was nearly three times more than during the inactive phases. The active （inactive） phases of ISO were characterized by low-level cyclonic （anticyclonic） circulation anomalies, higher （lower） midlevel relative humidity anomalies, and larger （smaller） vertical gradient anomalies of relative vorticity associated with enhanced （weakened） ITCZ convection anomalies. During the active phases, TCs tended to form in the center of the ITCZ region. Barotropic conversion from the low-level mean flow is suggested to be the major energy source for TC formation. The energy conversion mainly depended on the zonal and meridional gradients of the zonal flow during the active phases. However, barotropic conversion weakened greatly during the inactive phases. The relationship between the meridional gradient of absolute vorticity and low-level zonal flow indicates that the sign of the absolute vorticity gradient tends to be reversed during the two phases, whereas the same sign between zonal flow and the absolute vortieity gradient is more easily satisfied in the active phases. Thus, the barotropie instability of low-level zonal flow might be an important mechanism for TC formation over the WNP during the active phases of ISO.

关键词： intertropical convergence zone (ITCZ) intraseasonal oscillation (ISO) tropical cyclone (TC),modulation

Learning to see speckle in the weak laser field through multimode fiber

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Optoelectronics Letters 2025年

作者： JI Yunqi SONG Binbin LI Xueqing LI Yonghui The Engineering research center of Learning-Based Intelligent system (Ministry of Education)， the Key Laboratory of Computer Vision and systems (Ministry of Education)， and the School of Computer Science and Engineering， Tianjin University of Technology

Multimode fibers (MMFs) have great potential for endoscopic imaging due to the high number of modes and a small core diameter. Deep learning based on neural networks has received increasing attention in the field of scattering image reconstruction. However， most studies focus on designing complex network architectures to improve reconstruction， but these network models struggle to reconstruct images in a weak laser field. In the paper， a lightweight generative adversarial network model combined with a histogram specification algorithm is designed to reconstruct speckles in the weak laser field through MMF. Experimental results show that the reconstruction results of our algorithm have better metrics. Moreover， the model demonstrates excellent cross-domain generalization ability with regards to the Fashion-MNIST dataset. It is worth mentioning that we found that the speckles after inactivation still retain the ability to be reconstructed， which enhances the robustness of the model

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Tropical cyclones and multiscale climate variability: The active western North Pacific typhoon season of 2018

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Science China Earth Sciences 2020年第1期63卷 1-11页

作者： Liang WU Hongjie ZHANG Tao FENG Yulian TANG center for monsoon system research Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100190China College of Oceanography Hohai UniversityNanjing 210098China

The 2018 typhoon season in the western North Pacific(WNP) was highly active, with 26 named tropical cyclones(TCs) from June to November, which exceeded the climatological mean(22) and was the second busiest season over the past twenty years. More TCs formed in the eastern region of the WNP and the northern region of the South China Sea(SCS). More TCs took the northeast quadrant in the WNP, recurving from northwestward to northward and causing heavy damages in China's Mainland(69.73 billion yuan) in 2018. Multiscale climate variability is conducive to an active season via an enhanced monsoon trough and a weakened subtropical high in the WNP. The large-scale backgrounds in 2018 showed a favorable environment for TCs established by a developing central Pacific(CP) El Ni?o and positive Pacific meridional mode(PMM)episode on interannual timescales. The tropical central Pacific(TCP) SST forcing exhibits primary control on TCs in the WNP and large-scale circulations, which are insensitive to the PMM. During CP El Ni?o years, anomalous convection associated with the TCP warming leads to significantly increased anomalous cyclonic circulation in the WNP because of a Gill-type Rossby wave response. As a result, the weakened subtropical high and enhanced monsoon trough shift eastward and northward, which favor TC genesis and development. Although such increased TC activity in 2018 might be slightly suppressed by interdecadal climate variability, it was mostly attributed to the favorable interannual background. In addition, high-frequency climate signals,such as intraseasonal oscillations(ISOs) and synoptic-scale disturbances(SSDs), interacted with the enhanced monsoon trough and strongly modulated regional TC genesis and development in 2018.

关键词： Tropical cyclone Multiscale climate variability Typhoon season of 2018 Western North Pacific