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IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP)

作者： Kai Wang Hailiang Zhu Ganyu Liu Jinchao Mou Pei Zheng Gao Wei Northwestern Polytechnical University School of Electronics and Information Xi'an Shaanxi CN Beijing Research Institute of Telemetry Beijing CN The National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing CN

In this paper, a wideband terahertz meta-surface absorber with ultra-thin thickness is proposed. The meta-surface unit cell is composed of four-square unit cells in two different sizes. The the absorption higher than 90% from 3.24 to 3.98THz is achieved which can be regarded as a perfect terahertz absorber. Due to the symmetrical layout of meta-surface unit cell, the absorption spectrum can be maintained for any linear polarized terahertz wave, and the absorptance can be kept higher than 80% while the incident angle increases before 45°. Furthermore, the thermal response is calculated to be 0.23 $\mathbf{K} \cdot{\mathbf{m}\mathbf{m}^{2}/ \upmu \mathbf{W}}$ that well suited the requirements of FPA detectors.

关键词： Sensitivity Absorption Layout Detectors Stability analysis Compounds Thermal stability

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Design of Non-uniform Flexible Meta-surface for Antenna Beam-steering 3

Design of Non-uniform Flexible Meta-surface for Antenna Beam...

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3rd IEEE International Conference on Electronic Information and Communication technology, ICEICT 2020

作者： Qiu, Yuwei Jiang, Zhiye Zheng, Pei School of Electronic Information Northwestern Polytechnical University Xi'an China National Key Laboratory of Science and Technology on Test Physics Numerical Mathematics Beijing China

ISBN: (纸本)9781728190457

Design of non-uniform flexible meta-surface for antenna beam-steering is presented in this paper. By properly tuning the dimensions of quasi-I-shaped unit cells on meta-surface, we propose a bi-layer meta-surface that can achieve beam deflection of up to 34°. Horn antenna is adopted as the feed antenna to illuminate the meta-surface which is printed on flexible plastic sheet. The meta-surface is fixed on the outside surface of horn antenna with an electric motor, making it possible to slide relative to the aperture of feed antenna. The horn antenna together with the meta-surface will work like a projector when operating, the main-beam of the horn antenna can be steered when different frames of the meta-surface cover the horn aperture and the steering range is ±34°•Radiation reconfigurable is thus achieved through a simple structure. Prototype will be fabricated in the following research. © 2020 IEEE.

关键词： Horn antennas

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Seamless Prediction in China: A Review

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Advances in Atmospheric sciences 2023年第8期40卷 1501-1520页

作者： Hong-Li REN Qing BAO Chenguang ZHOU Jie WU Li GAO Lin WANG Jieru MA Yao TANG Yangke LIU Yujun WANG Zuosen ZHAO State Key Laboratory of Severe Weather and Institute of Tibetan Plateau MeteorologyChinese Academy of Meteorological SciencesBeijing 100081China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD) Nanjing University of Information Science and TechnologyNanjing 210044China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Department of Atmospheric Science School of Environmental StudiesChina University of GeosciencesWuhan 430074China China Meteorological Administration Key Laboratory for Climate Prediction Studies National Climate CenterChina Meteorological AdministrationBeijing 100081China Ensemble Forecasting Division CMA Earth System Modeling and Prediction Center(CEMC)Beijing 100081China School of Atmospheric Sciences Chengdu University of Information TechnologyChengdu 610225China

Seamless prediction is a weather-climate integrated prediction covering multiple time scales that include days,weeks,months,seasons,years,and *** prediction can provide different industries with information such as weather conditions and climate variations from the next few days to years,which have important impacts on economic and social development and important reference value for short-,medium-and long-term decision-making and planning of the ***,seamless prediction has received widespread attention from the international scientific community *** Chinese scientists have also carried out relevant research,this paper reviews the research in China on developments and applications of seamless prediction methods and prediction systems in recent *** them,the main progress of seamless prediction methods studies is reviewed from four aspects:short-and medium-range weather forecasting,subseasonal-to-seasonal,seasonal-to-interannual,and decadal climate *** terms of development and application of seamless prediction systems,the main achievements made by meteorological operational departments,scientific institutes,and universities in China in recent years are ***,some of the issues in seamless prediction that need further study are discussed.

关键词： seamless prediction weather-climate integrated prediction prediction system

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Influence of the NAO on Wintertime Surface Air Temperature over East Asia:Multidecadal Variability and Decadal Prediction

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Advances in Atmospheric sciences 2022年第4期39卷 625-642页

作者： Jianping LI Tiejun XIE Xinxin TANG Hao WANG Cheng SUN Juan FENG Fei ZHENG Ruiqiang DING Frontiers Science Center for Deep Ocean Multispheres and Earth System-Key Laboratory of Physical Oceanography-Institute for Advanced Ocean Studies-Academy of the Future Ocean Ocean University of ChinaQingdao 266100China Laboratory for Ocean Dynamics and Climate Pilot Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China College of Global Change and Earth System Sciences Beijing Normal UniversityBeijing 100875China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China

In this paper,we investigate the influence of the winter NAO on the multidecadal variability of winter East Asian surface air temperature(EASAT)and EASAT decadal *** observational analysis shows that the winter EASAT and East Asian minimum SAT(EAmSAT)display strong in-phase fluctuations and a significant 60-80-year multidecadal variability,apart from a long-term warming *** winter EASAT experienced a decreasing trend in the last two decades,which is consistent with the occurrence of extremely cold events in East Asia winters in recent *** winter NAO leads the detrended winter EASAT by 12-18 years with the greatest significant positive correlation at the lead time of 15 *** analysis shows that ENSO may affect winter EASAT interannual variability,but does not affect the robust lead relationship between the winter NAO and *** present the coupled oceanic-atmospheric bridge(COAB)mechanism of the NAO influences on winter EASAT multidecadal variability through its accumulated delayed effect of~15 years on the Atlantic Multidecadal Oscillation(AMO)and Africa-Asia multidecadal teleconnection(AAMT)*** NAO-based linear model for predicting winter decadal EASAT is constructed on the principle of the COAB mechanism,with good hindcast *** winter EASAT for 2020-34 is predicted to keep on fluctuating downward until~2025,implying a high probability of occurrence of extremely cold events in coming winters in East Asia,followed by a sudden turn towards sharp *** predicted 2020/21 winter EASAT is almost the same as the 2019/20 winter.

关键词： winter East Asian surface air temperature North Atlantic Oscillation Atlantic Multidecadal Oscillation Africa-Asia multidecadal teleconnection pattern coupled oceanic-atmospheric bridge multidecadal variability

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Rapid increase in warm-wet compound extreme events with high health risks in southern China:Joint influence of ENSO and the Indian Ocean

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Advances in Climate Change Research 2023年第6期14卷 856-865页

作者： Cai-Meng LIANG Liang ZHAO Shun-Wu ZHOU Xin-Yong SHEN Cun-Rui HUANG Yi-Hui DING Yan-Ju LIU Hao-Xin YAO Kai-Xing ZHOU Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersNanjing University of Information Science and TechnologyNanjing 210044China State Key Laboratory of Numerical Modeling for Atmosphere Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academyof SciencesBeijing100029China Key Laboratory of South China Sea Meteorological Disaster Prevention and Mitigation of Hainan Province Haikou 570203China Vanke School of Public Health Tsinghua UniversityBejing 100084China Institute of Healthy China Tsinghua UniversityBeijing 100084China National Climate Center China Meteorological AdministrationBejing 100081China Beijing Institute of Electronic System Engineering Bejing 100854China

High temperature and high humidity pose notable threats to the health and survival of humans,and the impact of compound extreme events involving multiple meteorological elements is usually greater than the sum of the impacts of individual extreme ***,there is limited research on the compound extreme meteorological events,defined based on the extreme of health risks rather than just the extreme of meteoro-logical elements,necessitating further investigation into their characteristics and underlying driving *** daily records of emergency ambulance dispatches from selected Chinese cities,together with daily average temperature and relative humidity data,this study identified and quantified warm-wet compound extreme events with high health risks(HRWWs)that occurred in southern China during *** revealed that HRWWs were most prevalent in the coastal region of southern *** annual frequency of HRWWs across China underwent a marked shift in 2014,with the rapid increase in recent years primarily contributed by the increase in summer HRWWs and advance and extension of the period of occurrence of HRWWs in *** analysis indicated that the changes in HRWWs in southern China during summer were primarily regulated by the EIl Nino-Southern Oscillation(ENSO)of the preceding winter and the springtime Indian Ocean basin-wide(IOBW)*** Nino and Indian Ocean warming force a reverse Walker circulation in the tropical Indian Ocean-western Pacific,strengthening the Philippine anticyclone(PAC)in *** weakens convection in the northwestern Pacific and enables the western Pacific subtropical high to extend westward over coastal areas of southern *** resulting abnormal atmospheric circulation causes prevailing subsidence over southern China,which is unfavorable for precipitation but conducive to maintaining high surface *** reduced precipitation,water vapor flux is increased owing to strengthened southwesterlies

关键词： Health risk Warm-wet compound events ENSO IOBW

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Application of improved genetic ant colony optimization in radar resource interference allocation 5

Application of improved genetic ant colony optimization in r...

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IET International Radar Conference 2020, IET IRC 2020

作者： Liao, Yanping Guo, Wenyuan Hu, Li Guo, Wenyuan Information and Communication Engineering Department Harbin Engineering University Harbin China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China

ISBN: (纸本)9781839535635

Under the condition of limited interference resources, how to maximize the benefits of multiple jammers interfering with multiple radars has become a research hotspot. This paper has designed a reasonable interference evaluation method. Aiming at the disadvantages of genetic algorithm and ant colony optimization, made some improvements, and combined genetic methods and ant colony optimization, besides, a new crossover and mutation method based on constraints is proposed, which overcomes the shortcomings of invalid iteration of genetic algorithm and easy to fall into local optimal solution of ant colony optimization. Through simulation analysis, the fused algorithm can reach the optimal value within a short number of iterations, improving the utilization efficiency of the jammer. © 2020 Institution of Engineering and technology. All rights reserved.

关键词： Ant colony optimization

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Mechanically Beam-steering of Horn Antenna Using Non-uniform Flexible Meta-Surface 6

Mechanically Beam-steering of Horn Antenna Using Non-uniform...

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6th IEEE International Conference on Computer and Communications, ICCC 2020

作者： Jiang, Zhiye Zheng, Pei Qiu, Yuwei Zhu, Hailiang Ding, Chenyu Wei, Gao National Key Laboratory of Science and Technology on Test Physics Numerical Mathematics Beijing China School of Electronics and Information Northwestern Polytechnical University Xi'an Shaanxi China

ISBN: (纸本)9781728186351

Research on mechanically beam-steering of horn antenna using non-uniform meta-surface is presented in this paper. After optimizing the layout of quasi-I-shaped unit cell, we designed a flexible bi-layer meta-surface that can bring a main beam deflection of 40°. When the meta-surface is sliding along the long side of horn antenna, the main beam can be steered accordingly in a range of ±40°. A mechanically radiation reconfigurable antenna is thus achieved by a simple structure. Sliding of the meta-surface relative to the horn can be realized by a motor-driven conveyor belt when the prototype is fabricated in the following research. © 2020 IEEE.

关键词： Horn antennas

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Prediction of ENSO using multivariable deep learning

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Atmospheric and Oceanic science Letters 2023年第4期16卷 51-56页

作者： Yue Chen Xiaomeng Huang Jing-Jia Luo Yanluan Lin Jonathon S.Wright Youyu Lu Xingrong Chen Hua Jiang Pengfei Lin Ministry of Education Key Laboratory for Earth System Modeling and Department for Earth System Science Tsinghua UniversityBeijingChina Institute for Climate and Application Research(ICAR)/CICFEM/KLME/ILCEC Nanjing University of Information Science and TechnologyNanjingChina Ocean and Ecosystem Sciences Division Fisheries and Oceans CanadaBedford Institute of OceanographyDartmouthNova ScotiaCanada National Marine Environmental Forecasting Center State Oceanic AdministrationBeijingChina State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina

本文基于残差神经网络和观测数据构建了一套深度学习多因子预报测模型,以改进厄尔尼诺-南方涛动(ENSO)的预报.该模型基于最大信息系数进行因子时空特征提取,并根据泰勒图的评估标准可自动确定关键预报因子进行预报.该模型在超前8个月以... 详细信息

本文基于残差神经网络和观测数据构建了一套深度学习多因子预报测模型,以改进厄尔尼诺-南方涛动(ENSO)的预报.该模型基于最大信息系数进行因子时空特征提取,并根据泰勒图的评估标准可自动确定关键预报因子进行预报.该模型在超前8个月以内的预报性能要优于当前传统的业务预报模式.2011–2018年间,该模型的预报性能优于多模式集成预报的结果.在超前6个月预报时效上,模型预报相关性可达0.82,标准化后的均方根误差仅为0.58°C,多模式集成预报的相关性和标准化后的均方根误差分别为0.70和0.73°C.该模型春季预报障碍问题有所缓解,并且自动选取的关键预报因子可用于解释热带和副热带热动力过程对于ENSO变化的影响.

关键词： ENSO预报深度学习春季预报障碍多维时空预报因子

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The significant roles of anthropogenic aerosols on surface temperature under carbon neutrality

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science Bulletin 2022年第5期67卷 470-473,M0003页

作者： Xiaofan Ma Gang Huang Junji Cao State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Laboratory for Regional Oceanography and Numerical Modeling Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

为了实现碳中和、达成巴黎协定低增温目标,人为排放将会大幅减少,未来大气中二氧化碳和气溶胶浓度会共同呈现下降趋势.本研究利用通用地球系统模式进行固定气溶胶模拟实验,探究碳中和情景下人为气溶胶对地表温度的影响.结果发现,未来人... 详细信息

为了实现碳中和、达成巴黎协定低增温目标,人为排放将会大幅减少,未来大气中二氧化碳和气溶胶浓度会共同呈现下降趋势.本研究利用通用地球系统模式进行固定气溶胶模拟实验,探究碳中和情景下人为气溶胶对地表温度的影响.结果发现,未来人为气溶胶减少产生的增暖效应将叠加在二氧化碳减少引起的降冷效应之上,使地表增温幅度扩大、降温速率减慢,从而延长实现巴黎协定低增温目标所需时间;在未来人为气溶胶减少背景下,地表温度出现不均匀变化,当其他地区出现长期变暖趋势时,北大西洋副极地地区出现长期变冷趋势.这主要是由于大西洋经向翻转流持续减弱引起的海洋向北热输送减少所致.本研究表明在规划碳中和的具体跨径时,需要考虑人为气溶胶对气候系统的重要调控作用.

关键词：人为气溶胶碳中和地表温度地球系统模式二氧化碳模拟实验气候系统增温幅度

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Design and Simulation of a Planar Printed Slot Array Antenna

Design and Simulation of a Planar Printed Slot Array Antenna

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IEEE International Workshop on Electromagnetics, Applications and Student Innovation (iWEM)

作者： Shi Xiaofei Shi Jiaxin Liu Jiaqi Fang Zhongyi Wang Lei Song Lizhong Shandong Institute of Space Electronic Technology Yantai China School of Electronics and Information Engineering Harbin Institute of Technology Harbin China School of Information Science and Engineering Harbin Institute of Technology at Weihai Weihai China National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing Institute of Space Long March Vehicle Beijing China Shandong Huayu Aerospace Technology Co. Ltd Yantai China

This paper designs an array antenna with a planar printed structure. The antenna element adopts a rectangular slot antenna, and the antenna element is excited by a T-shaped feeding structure. The microstrip power distribution network is used to feed the antenna radiator array with equal power. The microstrip power distribution network and slot radiator array are located on top and bottom of dielectric substrate, and the array antenna is implemented by use of the printed circuit technology. In order to improve the gain, a metal reflector ground is placed below the dielectric substrate. A planar printed slot array antenna working in X band is designed. The coaxial line is used to feed the array antenna at the bottom. The whole antenna structure is easy to feed and suitable for fabrication. The designed array antenna was numerically calculated using full wave electromagnetic simulation software. At a working frequency of 10.1GHz, the voltage standing wave ratio (VSWR) of the antenna is about 1.35, and the gain is about 21.46dB. The design of the antenna scheme can be used as a reference for the actual application of engineering.

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