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Direct vegetation response to CO2 rise is critical in projecting seasonal soil moisture droughts in mainland China

Journal of Hydrology 2025年 661卷

作者： Chen, Sisi Yuan, Xing Ji, Peng Yuan, Shanshui Lu, Chunhui The National Key Laboratory of Water Disaster Prevention Hohai University Nanjing China Key Laboratory of Hydrometeorological Disaster Mechanism and Warning of Ministry of Water Resources Nanjing University of Information Science and Technology Nanjing China State Key Laboratory of Earth System Numerical Modeling and Application Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China College of Hydrology and Water Resources Hohai University Nanjing China Yangtze Institute for Conservation and Development Hohai University Nanjing China

China is a hotspot of vegetation change, accounting for one fourth of the global total vegetation growth. Yet the influence of vegetation change on the future changes of soil moisture drought is two-fold as the response of vegetation physiology (e.g., physiological effects of CO2) and structure (e.g., leaf area index (LAI)) to CO2 rise can either mitigate or exacerbate soil moisture droughts. Here we investigate the net impact of these two factors and their relative importance against the climate change, based on a series of high-resolution land surface simulations. It is found that the direct vegetation response to CO2 rise—encompassing both physiological effects and changes in LAI—will reduce the drought frequency by 15 % in South China but exacerbate the drought severity by 47 % in North China at the 3.0 °C warming level, compared to the reference period (1971–2000). Such an inverse north–south spatial pattern is closely related to the spatial varying impact of vegetation greening, which enhances evapotranspiration and intensifies drought in the water-limited regions (e.g., North China) but has limited effect on evapotranspiration in the energy-limited regions (e.g., South China). Meanwhile, the physiological effects of CO2 mainly mitigate the drought and show small spatial variations. The national mean contribution of climate change, LAI change and CO2 physiological effects to future drought changes are 49 ∼ 54 %, 19 ∼ 27 % and 22 ∼ 28 %, respectively. And the relative importance of ecological factors would increase to >50 % when focusing on the difference among different warming levels. This study highlights the importance of direct vegetation response to CO2 rise in drought projections. © 2025 Elsevier B.V.

关键词： Soil moisture

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Development of Climate and Earth System Models in China: Past Achievements and New CMIP6 Results

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Journal of Meteorological Research 2020年第1期34卷 1-19页

作者： Tianjun ZHOU Ziming CHEN Liwei ZOU Xiaolong CHEN Yongqiang YU Bin WANG Qing BAO Ying BAO Jian CAO Bian HE Shuai HU Lijuan LI Jian LI Yanluan LIN Libin MA Fangli QIAO Xinyao RONG Zhenya SONG Yanli TANG Bo WU Tongwen WU Xiaoge XIN He ZHANG Minghua ZHANG State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029 College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049 First Institute of Oceanography Ministry of Natural ResourcesQingdao 266061 School of Atmospheric Science Nanjing University of Information Science&TechnologyNanjing 210044 Chinese Academy of Meteorological Sciences China Meteorological AdministrationBeijing 100081 Tsinghua University Beijing 100084 National Climate Center China Meteorological AdministrationBeijing 100081 International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029

The Earth–Climate System Model(ECSM)is an important platform for multi-disciplinary and multi-sphere integration research,and its development is at the frontier of international geosciences,especially in the field of global *** research and development(R&D)of ECSM in China began in the 1980 s and have achieved great *** China,ECSMs are now mainly developed at the Chinese Academy of sciences,ministries,and *** a brief review of the development history of Chinese ECSMs,this paper summarized the technical characteristics of nine Chinese ECSMs participating in the Coupled Model Intercomparison Project Phase 6 and preliminarily assessed the basic performances of four Chinese models in simulating the global climate and the climate in East *** projected changes of global precipitation and surface air temperature and the associated relationship with the equilibrium climate sensitivity under four shared socioeconomic path scenarios were also ***,combined with the international situation,from the perspective of further improvement,eight directions were proposed for the future development of Chinese ECSMs.

关键词： Earth–Climate System Model(ECSM) Chinese models Coupled Model Intercomparison Project Phase 6(CMIP6) model performance climate prediction and projection outlook

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Performance analysis of one-step prediction-based cognitive jamming in jammer-radar countermeasure model

Performance analysis of one-step prediction-based cognitive ...

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IET International Radar Conference 2018, IRC 2018

作者： Gao, Lu Liu, Li Cao, Yang Wang, Shangyue You, Shixun National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China DFH Satellite Co. Ltd Beijing China Harbin Engineering University 145 Nantong Street Nangang District Harbin China

Strong adaptive radar, such as cognitive radar (CNR), can perform various missions while ensuring its own security in electronic warfare, via detecting environments and changing the radar parameters in real time. Unfortunately, most of the current military countermeasures, such as jamming-based electronic countermeasures, have rarely been related to jamming for CNR. Since the behaviours of radar in the traditional design of the jammer-radar scenario are always static, it is easy to create a subjective or local optimal jamming effect. In order to dynamically analyse the execution process of a complete jamming radar mission, this work establishes an equivalent attack-defence game in which the radar is regarded as a defence decision agent, and the jammer is an attack decision agent. The attributes of the game's players, the rules of the game, and the conditions for the end of the game are set clearly by setting reasonable parameters. After searching for antagonism strategies by exhaustive method, it can be found that the survivability of the predictive cognitive jamming is much stronger than that of the normal jamming based on real-time sampling data of radars. This conclusion is demonstrated through a 1 ms simulation of the game process. © This is an open access article published by the IET under the Creative Commons Attribution License (http://***/licenses/by/3.0/)

关键词： Jamming

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Deformed relativistic Hartree-Bogoliubov theory in continuum with a point-coupling functional. II. Examples of odd Nd isotopes

arXiv

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arXiv 2022年

作者： Pan, Cong Cheoun, Myung-Ki Choi, Yong-Beom Dong, Jianmin Du, Xiaokai Fan, Xiao-Hua Gao, Wei Geng, Lisheng Ha, Eunja He, Xiao-Tao Huang, Jinke Huang, Kun Kim, Seonghyun Kim, Youngman Lee, Chang-Hwan Lee, Jenny Li, Zhipan Liu, Zhi-Rui Ma, Yiming Meng, Jie Mun, Myeong-Hwan Niu, Zhongming Papakonstantinou, Panagiota Shang, Xinle Shen, Caiwan Shen, Guofang Sun, Wei Sun, Xiang-Xiang Wu, Jiawei Wu, Xinhui Xia, Xuewei Yan, Yijun Yiu, To Chung Zhang, Kaiyuan Zhang, Shuangquan Zhang, Wei Zhang, Xiaoyan Zhao, Qiang Zheng, Ruyou Zhou, Shan-Gui State Key Laboratory of Nuclear Physics and Technology School of Physics Peking University Beijing100871 China Institute Soongsil University Seoul156-743 Korea Republic of Department of Physics Pusan National University Busan46241 Korea Republic of Institute of Modern Physics Chinese Academy of Sciences Lanzhou730000 China School of Physics University of Chinese Academy of Sciences Beijing100049 China School of Physical Science and Technology Southwest University Chongqing400715 China School of Physics and Microelectronics Zhengzhou University Zhengzhou450001 China School of Physics Beihang University Beijing102206 China Department of Physics Hanyang University Seoul04763 Korea Republic of College of Materials Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing210016 China Rare Isotope Science Project Institute for Basic Science Daejeon34000 Korea Republic of Department of Physics The University of Hong Kong Pokfulam999077 Hong Kong School of Mathematical Sciences Peking University Beijing100871 China Korea Institute of Science and Technology Information Daejeon34141 Korea Republic of School of Physics and Optoelectronics Engineering Anhui University Hefei230601 China School of Science Huzhou University Huzhou313000 China School of Nuclear Science and Technology University of Chinese Academy of Sciences Beijing100049 China CAS Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences Beijing100190 China School of Physics and Electronic Engineering Center for Computational Sciences Sichuan Normal University Chengdu610068 China Center for Exotic Nuclei Studies Institute for Basic Science Daejeon34126 Korea Republic of School of Physical Sciences University of Chinese Academy of Sciences Beijing100049 China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator Lanzhou730000 China Synergetic Innovation Center for Quantum Eff

Background: One fascinating frontier in nuclear physics is the study of exotic nuclei. The deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc), which simultaneously includes the nuclear superfluidity, deformation, and continuum effects, can provide proper descriptions for both stable and exotic nuclei. In Zhang, et al. [Phys. Rev. C 102, 024314 (2020)], the DRHBc theory based on the point-coupling density functionals was developed and the DRHBc calculation, previously accessible only for light nuclei, was extended for all even-even nuclei in the nuclear chart. The ground-state properties for the even-even nuclei with 8 ≤ Z ≤ 120 from the DRHBc calculations have been summarized in Zhang, et al. [At. Data Nucl. Data Tables 144, 101488 (2022)]. Purpose: The aim of this work is to extend the point-coupling DRHBc theory to odd-A and odd-odd nuclei and examine its applicability by taking odd-A Nd isotopes as examples. Method: In the DRHBc theory, the densities and potentials with axial deformation are expanded in terms of Legendre polynomials, and the relativistic Hartree-Bogoliubov equations are solved in a Dirac Woods-Saxon basis to include the continuum effects. For an odd-A or odd-odd nucleus, the blocking effect of unpaired nucleon(s) is taken into account with the equal filling approximation. To determine its ground state, an automatic blocking procedure is adopted, in which the orbital with the lowest quasiparticle energy is blocked during the iteration. This procedure is justified by comparing with the results from the orbital-fixed blocking calculations, in which the blocked orbital near the Fermi surface is fixed during the iteration. The ground states for both light and heavy nuclei can be provided by the automatic blocking procedure as the orbital-fixed blocking procedure, but with considerably reduced computational cost. Results: The numerical details for even-even nuclei, including the convergence on the energy cutoff, angular momentum cutof

关键词： Ground state

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Adaptive feed-forward control for seeker based on the disturbance observer

Adaptive feed-forward control for seeker based on the distur...

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IEEE Advanced Information technology, Electronic and Automation Control Conference (IAEAC)

作者： Xin Liu Zhenhong Niu Yi Shu Lian Xue Mingchao Zhu National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences

In order to improve the tracking and stabilization performance, a control method combining disturbance observer and adaptive feed-forward control using parameterization is proposed for seeker stabilized platforms. The system identification algorithm is used to identify dynamic model of the true plant. Then the discrete-time disturbance observer is designed. The feedback loop controller is designed using pole-placement techniques. The recursive least square (RLS) adaptive filter is used to build the inverse model of the feedback control loop and in this way, the feed-forward control is constructed. The adaptive filter and the feedback loop constitute a control scheme with two degrees-of-freedom (DOF). Tracking experiments conducted on velocity command inputs verify the validity of the adaptive feed-forward controller. Experimental results show that this method responses quickly to commands. For a sinusoidal signal at the frequency of 30Hz, the adaptive feed-forward controller can obtain an amplitude response without attenuation and the phase lag is reduced to 11° in contrast with the feedback control whose phase lag is 60°. This method significantly improves the transient performance and is superior to the feedback control alone.

关键词： Adaptive filters Feedback control Disturbance observers Feedforward systems Low pass filters Tracking loops Stability analysis

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A Direct Position Determination Method for Four-station TDOA Location System

A Direct Position Determination Method for Four-station TDOA...

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Signal, Information and Data Processing (ICSIDP), IEEE International Conference on

作者： Sun-Rui Qi Chen-Shun Yuan Bai-Jin Liang Gao-Lu Li-Hu Sun-Heng BEIJING INSTITUTE OF SPACE LONG MARCH VEHICLE National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China

ISBN: (数字)9781728123455

ISBN: (纸本)9781728123462

Aiming at the four-station networked TDOA (Time Difference of Arrival) localization system, a direct location method based on electronic elevation map search is proposed, the Geometric Dilution Precision (GDOP) is derived, and the factors affecting the location accuracy are analyzed. The location method under real conditions is also simulated, and its feasibility is demonstrated, which provides a new engineering method for networked TDOA location.

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An Improved Adaptive Pulse Compression Algorithm Based on Linear Frequency Modulation Signal

An Improved Adaptive Pulse Compression Algorithm Based on Li...

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Signal, Information and Data Processing (ICSIDP), IEEE International Conference on

作者： Jinliang Bai Peng Qin Hu Li Ran Zhang Xinyu Zhang National key laboratory of science and technology on test physics and numerical mathematics Beijing Institute of Space Long March Vehicle Beijing China

ISBN: (数字)9781728123455

ISBN: (纸本)9781728123462

In this paper, the radar signal is optimized based on the pulse compression repair (PCR) algorithm, which mainly reduces the computational amount to makes it more advantageous to achieve. The main idea is to implement PCR in a parallel way. The method of implementing parallelism is well known, that is, the signal is segmented, and different segmentation methods can be adopted according to different signal models. In this paper, the chirp signal is mainly processed by decimation and segmentation, and some intrinsic benefits of the performance and computational balance of the proposed method are discussed.

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Broadband Dual-Polarized Antenna with Enhanced Front-To-Back Ratio Using Meta-surface

Broadband Dual-Polarized Antenna with Enhanced Front-To-Back...

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Asia-Pacific Conference on Microwave

作者： Pei Zheng Yuwei Qiu Jinliang Bai Ziwei Xu Xin Liu Jiaqi Liu Jun Li Shuo Zhang Hailiang Zhu Gao Wei National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China Northwestern Polytechnical University Xi'an Shaanxi China

ISBN: (数字)9781728135175

ISBN: (纸本)9781728135182

A novel broadband dual-polarized dipole antenna with enhanced front-to-back ratio is proposed. By placing metasurface around the radiators, the proposed dipole antenna exhibits wide impedance bandwidth (S11&S22 ≤ -12dB) of 52% from 0.675 to 1.15 GHz, covering the lower frequency band (0.69~0.96GHz) of base station antenna. Simulated results show that the front-to-back ratio can be increased by 4-5dB after adding the meta-surface, radiation pattern with enhanced frontto-back ratio (FBR) higher than 20dB were achieved over the operating frequency range. In addition, the antenna architecture is simple and easy to fabricate in base stations that can be used in modern mobile communication systems.

关键词： Dipole antennas Broadband antennas Antenna radiation patterns Probes Broadband communication Bandwidth

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Physical Layer Security of Cooperative Network with Machine Learning-based Relay Selection

Physical Layer Security of Cooperative Network with Machine ...

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IEEE International Symposium on Electromagnetic Compatibility (EMC-Beijing)

作者： Fang Liu Yajuan Wang Hu Li Beijing University of Posts and Telecommunications Beijing China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China

ISBN: (数字)9781728144160

ISBN: (纸本)9781728144177

We explore the potential of machine learning for relay selection in a cooperative multi-relay wiretap network with decode-and-forward (DF) protocol, aiming to enhance the physical layer security. Such network is divided into two scenarios according to whether the channel state information (CSI) of wiretap links is available or not for source, when it is assumed that the CSI of the main links has been known at the source. In addition, two machine learning-based schemes, namely, the convolutional neural network(CNN)-based multi-classifier and the support vector machine(SVM)-based multi-classifier, are proposed to characterize the conventional optimization problem of cooperative relay selection as a multi-classification problem in two scenarios mentioned above. In our study, we provide more insight into the spatial correlation of CSI and make the first attempt to introduce the CNN for relay selection in a cooperative multi-relay wiretap network. Finally, the simulation results indicate that two machine learning-based with relatively low selection complexity and less feedback amount achieve substantially the same secrecy performance as the conventional selection scheme.

关键词： Relays Training Machine learning Support vector machines Physical layer security Neurons Correlation

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Influences of different definitions of the winter NAO index on NAO action centers and its relationship with SST

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Atmospheric and Oceanic science Letters 2019年第5期12卷 320-328页

作者： JING Yujie LI Yangchun XU Yongfu FAN Guangzhou School of Atmospheric Sciences ζhengdu University of Information TechnologyChengduChina State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina Laboratory for Regional Oceanography and Numerical Modeling Qingdao National Laboratory for Marine Science and TechnologyQingdaoChina Department of Atmospheric Chemistry and Environmental Sciences College of Earth ScienceUniversity of Chinese Academy of SciencesBeijingChina

Winter North Atlantic Oscillation(NAO)indexes from observations based on various winter durations are *** show that there are significant differences in the interannual and decadal variations of these NAO *** the same data source,a different definition of winter duration can lead to different signs of NAO index in some years,which mainly appear to be in the period of decadal phase *** different winter durations induce different cycles of the observation-based *** longer the winter duration,the stronger the decadal *** NAO defined by different winter durations also can generate different descriptions of the NAO action centers,including the position and *** longer the winter duration,the more southerly action centers appear to *** movement of the action centers affects not only site-based NAO indexes but also those defined by other methods,such as empirical orthogonal function(EOF)*** length of time used in EOF analysis has a great influence on the spatial pattern of the NAO mode,which results in a considerable difference between the corresponding NAO *** of which NAO index is used,the NAO-related SST anomalies show the same tripole *** longer the winter duration,the more significant the relationship between the NAO and SST affected by the timescale of sea-air interaction.

关键词： NAO index winter duration period action centers sea surface temperature

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