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Effectiveness of Precursor Emission Reductions for the control of Summertime Ozone and PM2.5 in the Beijing–Tianjin–Hebei Region under Different Meteorological Conditions

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Advances in Atmospheric sciences 2025年第4期42卷 653-669页

作者： Jing QIAN Hong LIAO Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science&TechnologyNanjing 210044JiangsuChina

We used observed concentrations of air pollutants,reanalyzed meteorological parameters,and results from the Goddard Earth Observing System Chemical Transport Model to examine the relationships between concentrations of maximum daily 8-h average ozone(MDA8 O_(3)),PM_(2.5)(particulate matter with diameter of 2.5μm or less),and PM_(2.5)components and 2-m temperature(T2)or relative humidity(RH),as well as the effectiveness of precursor emission reductions on the control of O_(3) and PM_(2.5) in Beijing–Tianjin–Hebei(BTH)under different summertime temperature and humidity *** observed(simulated)MDA8 O_(3) and PM_(2.5) concentrations increased as T2 went up,with linear trends of 4.8(3.2)ppb℃^(−1) and 1.9(1.5)μg m^(−3)℃^(−1),*** results showed that the decreases in MDA8 O_(3) from precursor emission reductions were more sensitive to T2 than to *** a larger proportion of volatile organic compound(VOC)emissions at higher T2 was more effective for the control of summertime O_(3) in *** the control of summertime PM_(2.5) in BTH,reducing nitrogen oxides(NOx)combined with a small proportion of VOCs was the best *** magnitude of reduction in PM_(2.5) from reducing precursor emissions was more sensitive to RH than to T2,with the best efficiency at high *** from this study are helpful for formulating effective policies to tackle O_(3) and PM_(2.5) pollution in BTH.

关键词： ozone PM_(2.5) emission reductions meteorological conditions

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Covert Rate Characterization under Multi-Antenna Detection:A Study on Warden’s CSI Availability and Noise Uncertainty

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China Communications 2025年第2期22卷 143-159页

作者： Zhang Yuchen Xiao Sa Wang Jianquan Ning Boyu Yuan Xiaojun TangWanbin National Key Laboratory of Wireless Communications University of Electronic Science and Technology of ChinaChengdu 611731China Kash Institute of Electronics and Information Industry Kash844000 China

In this paper,we investigate covert communications under multi-antenna detection,and explore the impacts of the warden’s channel state information(CSI)availability and the noise uncertainty on system covert *** detection performance at warden is analyzed in two cases under the perfect and statistical CSI at warden,*** particular,for the former one,the warden utilizes the likelihood ratio(LR)detector,while for the latter one,the generalized likelihood ratio(GLR)detector is *** first consider the scenario where the blocklength is finite,and demonstrate that the covert rate under both cases asymptotically goes to zero as the blocklength goes to ***,we take the noise uncertainty at the warden into account which leads to positive covert rate,and characterize the covert rate for infinite ***,we derive the optimal transmit power for the legitimate transmitter that maximizes the covert ***,the rate gap under two cases,with different CSI availability at the warden,can be presented in closed ***,numerical results validate the effectiveness of our theoretical analysis and also demonstrate the impacts of the factors studied on the system covertness.

关键词： channel state information covert communications multiple antenna noise uncertainty

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Effect of industrial alkene ozonolysis on atmospheric H_(2)SO_(4)formation

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Journal of Environmental sciences 2025年第4期150卷 466-476页

作者： Xing Wang Xiaowen Shi Youling Jiang Yan Ma Jun Zheng School of Environmental Science and Engineering Nanjing University of Information Science and TechnologyNanjing 210044China Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Nanjing 210044China Jiangsu Provincial Academy of Environmental Sciences Nanjing 210036China

This study has employed the master chemical mechanism(MCM)to investigate the influence of the ozone oxidation pathways in the atmospheric formation of H_(2)SO_(4)from shortchain olefins in industrialized ***-situ H_(2)SO_(4)formation data were obtained using a high-resolution chemical ionization time-of-flight mass spectrometer,and the simulated H_(2)SO_(4)concentrations calculated using updated parameters for the MCM model exhibited good agreementwith *** the simulation analysis of different reaction pathways involved in H_(2)SO_(4)formation,hydroxyl radicals were found to dominate H_(2)SO_(4)production during the daytime,while olefin ozone oxidation contributed up to 65%of total H_(2)SO_(4)production during the night-time.A sensitivity analysis of the H_(2)SO_(4)production parameters has revealed a high sensitivity to changes in sulfur dioxide,and a relatively high sensitivity to olefins with fast ozonolysis reaction rates and bimolecular reaction rates of resulting stabilized Criegee Intermediates.A high relative humidity promotes daytime H_(2)SO_(4)formation,but has an inhibiting effect during the night-time due to the different dominant reaction pathways.

关键词： Gaseous sulfuric acid Alkene ozonation reaction MCM model Sensitivity analysis

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Combining Local Electromagnetic Scattering and Global Structure Features for SAR Open Set Recognition

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IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing 2025年 18卷 12572-12587页

作者： Lin, Qinjie Sun, Hao Xu, Yanjie Wang, Junyu Ji, Kefeng Kuang, Gangyao National University of Defense Technology State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System College of Electronic Science and Technology Changsha410073 China

Automatic target recognition (ATR) is crucial for synthetic aperture radar (SAR) image interpretation. However, existing SAR ATR primarily rely on algorithms from the field of computer vision, many methods have not adequately considered the imaging sensitivity of SAR images. Moreover, SAR ATR typically follows the closed set assumption, but in dynamic and open real-world environments, SAR systems may encounter target classes that have not been seen during training. To address these issues, this paper proposes a SAR open set recognition (OSR) method that combines local electromagnetic scattering and global structure features. The global structural features focus on the overall relationship between target and background, while the local electromagnetic scattering features can effectively capture the scattering characteristics of target. Hence, we construct a global and local feature guidance (GLGE) network, fuses these complementary features as prior knowledge to guide deep features. Then, a class-anchor-based loss function is constructed by Anchor loss and Tuple loss, which cluster the features of known classes targets around predefined class anchors. Finally, the distance ratio is calculated to identify known classes targets and reject unknown classes targets. The experimental results on the MSTAR and SAR-ACD datasets show that our method outperforms other OSR methods in recall, precision, F1, and accuracy, demonstrating a superior performance in OSR. © 2008-2012 IEEE.

关键词： Automatic target recognition

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Flexible Inverse Design of Microwave Filter Customized on Demand With Wavelet Transform Deep Learning

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IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems 2025年第3期44卷 806-817页

作者： Xu, Kuiwen Wang, Jianguo Cai, Jialin Ma, Xuetiao Lv, Qinyi Chen, Shichang Liu, Jie Liu, Jun Hangzhou Dianzi University Innovation Center for Electronic Design Automation Technology The Key Laboratory of RF Circuits and Systems Ministry of Education Hangzhou310018 China Chang'an Campus Northwestern Polytechnical University School of Electronic Information Xi'an710060 China University of Electronic Science and Technology of China School of Electronic Science and Engineering Chengdu610054 China Information Science Academy China Electronics Technology Group Corporation Beijing100846 China

Artificial intelligence (AI) techniques are increasingly being used for the inverse design of microwave devices. However, several challenges, including intensive computation costs for training samples, high-dimensional data, nonuniformity, and low-quality samples in the design space, can negatively impact the final modeling performance. To alleviate these issues, a high-quality sampling inverse design scheme incorporating wavelet transform deep learning (HQS-WTDL) is proposed to achieve customized, automated microwave filter design. In the forward simulation-based sampling, particle swarm optimization (PSO) is used to tentatively select rule-defined samples. Multilabel synthetic minority over-sampling technique (MLSMOTE) is then applied to enlarge the training samples and improve their uniformity in the design space. An inverse modeling approach using neural networks to map the nonlinear relationship between a given set of S-parameters and required filter structural parameters is presented. Given that the dimension of the S-parameters is much higher than that of the structure parameters, the corresponding neural network used in this approach is deep and complex, with multiple layers and neurons. To reduce the number of input variables, the S-parameters are subjected to wavelet transformation, allowing for more efficient representation by the neural network. The proposed method is validated using a band-pass microstrip hairpin filter as an example. Results demonstrate that the proposed approach achieves better modeling effectiveness and inverse design efficiency than conventional methods. In addition, the proposed method allows for fast customization of device parameters, such as center frequencies and bandwidths with good prediction accuracy. © 1982-2012 IEEE.

关键词： Inverse problems

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B+-Tree-Quantization-Based Shared Secret key Extraction Scheme From Atmospheric Optical Wireless Channel

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IEEE Transactions on Communications 2025年第5期73卷 3394-3408页

作者： Pan, Gang Chen, Chunyi Changchun University of Science and Technology School of Computer Science and Technology Changchun130022 China Changchun University of Science and Technology School of Computer Science and Technology Key Laboratory of Photoelectric Measurement & Control and Optical Information Transfer Technology Changchun130022 China Chongqing Research Institute Changchun University of Science and Technology Chongqing401135 China

To reduce key disagreement rate and increase key generation rate, this paper proposes a lightweight and robust shared secret key extraction scheme from atmospheric optical wireless channel. A conception of grouping samples by using B+ tree and quantizing groups is introduced to improve the balance of distribution of channel measurement values in quantization intervals. Based on the conception, a basic B+ tree quantization algorithm (B-BPTQ) and a compensation-technology-based B+ tree quantization algorithm (C-BPTQ) are designed. A LDPC-based multi-scale information reconciliation algorithm (LDPC-MSIR) is put forward to simplify information reconciliation and reduce its computation complexity. An enhanced randomness post-processing algorithm is formulated to increase statistical randomness of initial key sequence. Finally, the performance of the proposed scheme is validated by numerical simulations and field experiments. The experimental results show that it has better performance in terms of key disagreement rate, key generation rate and key randomness compared with other schemes. © 1972-2012 IEEE.

关键词： Optical communication

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First observation results of Macao science Satellite-1 on lightning-induced electron precipitation

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science China Earth sciences 2025年第1期68卷 1-10页

作者： Yongping WANG Yixin SUN Qiugang ZONG Gaopeng LU Xudong GU Ze-Jun HU Bin LI Key Laboratory for Polar Science Ministry of Natural ResourcesPolar Research Institute of ChinaShanghai 200136China Institute of Space Physics and Applied Technology Peking UniversityBeijing 100871China State Key Laboratory of Lunar and Planetary Science Macao University of Science and TechnologyMacao 999078China School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China School of Electronic Information Wuhan UniversityWuhan 430072China

The Medium-energy Electron Spectrometers(MES)is a space-borne instrument onboard Macao science Satellite-1(MSS-1)dedicated to monitoring the typical charged particle radiation characteristics in the satellite orbit and the process of their occurrence and development,including short bursts of lightning-induced electron precipitation(LEP).This paper presents the first results of the LEP measurements by the MSS-1.47 LEP events are identified with the routine operation for 3 months since satellite launch,all within the range of 1.5

关键词： Lightning-induced electron precipitation Inner radiation belts Energetic electrons Macao science Satellite-1

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Enhanced piezoelectricity and lager strain in Bi0.5Li0.5HfO3 doped sodium potassium niobate-based ceramics with high Curie temperatures

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Ceramics International 2025年第15期51卷 20992-20998页

作者： Li, Yuxuan Peng, Zhanhui Chai, Qizhen Wang, Yuanhao Nie, Xinru Wei, Lingling Liang, Pengfei Wu, Di Chao, Xiaolian Yang, Zupei Key Laboratory for Macromolecular Science of Shaanxi Province Shaanxi Key Laboratory for Advanced Energy Devices Shaanxi Engineering Laboratory for Advanced Energy Technology School of Materials Science and Engineering Shaanxi Normal University Shaanxi Xi'an710062 China Electronic Materials Research Laboratory Key Laboratory of the Ministry of Education School of Electronic Science and Engineering Faculty of Electronic and Information Engineering Xi'an Jiaotong University Xi'an710049 China School of Physics and Information Technology Shaanxi Normal University Shaanxi Xi'an710062 China School of Chemistry and Chemical Engineering Shaanxi Normal University Shaanxi Xi'an710062 China

High-temperature electronic ceramics are indispensable in applications such as the automotive sector, aerospace, oil exploration and other fields. Potassium sodium niobate-based (KNN-based) ceramics have emerged as critical materials for the development of environmentally friendly high-temperature sensors, filters, and other electronic devices. However, achieving a combination of superior piezoelectric properties and a high Curie temperature in KNN-based ceramics remains a significant challenge. In this study, we employed a strategy of constructing an orthorhombic-tetragonal (O-T) phase boundary with the objective of enhancing the piezoelectric properties of KNN-based ceramics and introduced Li+ to optimize the Curie temperature. In (1-x)K0.48Na0.52NbO3-xBi0.5Li0.5HfO3 ceramics, we realized high piezoelectric constant ∼ 340 pC/N, large strain (∼0.21 %) and elevated Curie temperature (Tc ∼ 354 °C) simultaneously. These findings not only identify a promising candidate for high-temperature sensors and filters but also provide valuable insights for advancing the design of high Curie temperature and lead-free piezoelectric ceramics based on KNN systems. © 2025 Elsevier Ltd and Techna Group S.r.l.

关键词： Piezoelectricity

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Multi-parameter ultrasound imaging for musculoskeletal tissues based on a physics informed generative adversarial network

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Chinese Physics B 2025年第4期34卷 442-455页

作者： Pengxin Wang Heyu Ma Tianyu Liu Chengcheng Liu Dan Li Dean Ta Institute of Biomedical Engineering&Technology Academy for Engineering and TechnologyFudan UniversityShanghai 200433China State Key Laboratory of Integrated Chips and Systems Fudan UniversityShanghai 201203China Department of Electronic Engineering School of Information Science and TechnologyFudan UniversityShanghai 200438China Department of Biomedical Engineering School of Information Science and TechnologyFudan UniversityShanghai 200438China

Full waveform inversion(FWI)has showed great potential in the detection of musculoskeletal ***,FWI is an ill-posed inverse problem and has a high requirement on the initial model during the imaging *** inaccurate initial model may lead to local minima in the inversion and unexpected imaging results caused by cycle-skipping *** learning methods have been applied in musculoskeletal imaging,but need a large amount of data for *** by work related to generative adversarial networks with physical informed constrain,we proposed a method named as bone ultrasound imaging with physics informed generative adversarial network(BUIPIGAN)to achieve unsupervised multi-parameter imaging for musculoskeletal tissues,focusing on speed of sound(SOS)and *** the in-silico experiments using a ring array transducer,conventional FWI methods and BUIPIGAN were employed for multiparameter imaging of two musculoskeletal tissue *** results were evaluated based on visual appearance,structural similarity index measure(SSIM),signal-to-noise ratio(SNR),and relative error(RE).For SOS imaging of the tibia–fibula model,the proposed BUIPIGAN achieved accurate SOS imaging with best *** specific quantitative metrics for SOS imaging were SSIM 0.9573,SNR 28.70 dB,and RE 5.78%.For the multi-parameter imaging of the tibia–fibula and human forearm,the BUIPIGAN successfully reconstructed SOS and density distributions with SSIM above 94%,SNR above 21 dB,and RE below 10%.The BUIPIGAN also showed robustness across various noise levels(i.e.,30 dB,10 dB).The results demonstrated that the proposed BUIPIGAN can achieve high-accuracy SOS and density imaging,proving its potential for applications in musculoskeletal ultrasound imaging.

关键词： ultrasound image physics informed generative adversarial network musculoskeletal imaging

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Turbulent drag reduction by sector-shaped counter-flow dielectric barrier discharge plasma actuator

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Chinese Physics B 2025年第2期34卷 362-370页

作者： Borui Zheng Shaojie Qi Minghao Yu Jianbo Zhang Linwu Wang Dongliang Bian School of Automation and Information Engineering Xi’an University of TechnologyXi’an 710048China School of Mechanical and Precision Instrument Engineering Xi’an University of TechnologyXi’an 710048China Science and Technology on Plasma Dynamics Laboratory Air Force Engineering UniversityXi’an 710038China Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi’an 710048China Shaanxi University Key Laboratory of Photonic Power Devices and Discharge Regulation Xi’an 710048China

The primary objective in aircraft transportation is to minimize turbulent drag, thereby conserving energy and reducing emissions. We propose a sector-shaped counter-flow dielectric barrier discharge plasma actuator, which leverages jet synthesis for drag reduction. A drag control experiment was conducted in a low-speed wind tunnel with a controlled flow velocity of 9.6 m/s(Re = 1.445 × 10^(4)). This study investigated the effects of varying pulse frequencies and actuation voltages on the turbulent boundary layer. Using a hot-wire measurement system, we analyzed the pulsating and time-averaged velocity distributions within the boundary layer to evaluate the streamwise turbulent drag reduction. The results show that the local TDR decreases as the pulse frequency increases, reaching a maximum reduction of approximately 20.97% at a pulse frequency of 50 Hz. In addition, as the actuation voltage increases, the friction coefficient decreases, increasing the drag reduction rate. The maximum drag reduction of approximately 33.34% is achieved at an actuation voltage of 10 kV.

关键词： plasma flow control turbulent boundary layer turbulent drag reduction

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