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Joint mass-and-energy test of the equivalence principle at the 10−10 level using atoms with specified mass and internal energy

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Physical Review A 2021年第2期104卷 022822-022822页

作者： Lin Zhou Chuan He Si-Tong Yan Xi Chen Dong-Feng Gao Wei-Tao Duan Yu-Hang Ji Run-Dong Xu Biao Tang Chao Zhou Sachin Barthwal Qi Wang Zhuo Hou Zong-Yuan Xiong Yuan-Zhong Zhang Min Liu Wei-Tou Ni Jin Wang Ming-Sheng Zhan State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics Innovation Academy for Precision Measurement Science and Technology Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics Wuhan 430071 China School of Physical Sciences University of Chinese Academy of Sciences Beijing 100049 China Light and Matter Physics Raman Research Institute Sadashivanagar Bangalore 560080 India Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100190 China

We use rubidium atoms with specified mass and internal energy to carry out a joint mass-energy test of the equivalence principle (EP). We improve the four-wave double-diffraction Raman transition method (4WDR) we proposed before to select atoms with a certain mass and angular momentum state, and form a dual-species atom interferometer. By using the extended 4WDR to Rb85 and Rb87 atoms with different angular momenta, we measure their differential gravitational acceleration, and we determine the value of the Eötvös parameter, η, which measures the strength of the violation of EP. The Eötvös parameters of the four paired combinations Rb85|F=2〉−Rb87|F=1〉, Rb85|F=2〉−Rb87|F=2〉, Rb85|F=3〉−Rb87|F=1〉, and Rb85|F=3〉−Rb87|F=2〉 were measured to be η1=(1.5±3.2)×10−10, η2=(−0.6±3.7)×10−10, η3=(−2.5±4.1)×10−10, and η4=(−2.7±3.6)×10−10, respectively. The violation parameter of mass is constrained to η0=(−0.8±1.4)×10−10, and that of internal energy to ηE=(0.0±0.4)×10−10 per reduced energy ratio a (a=hν0/mi85c2, and ν0=1 GHz). This work opens a door for joint tests of two attributes beyond the traditional pure mass or energy tests of EP with quantum systems.

关键词： Atom interferometry Coherent control Atoms Mach-Zehnder atom interferometry

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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 two-stage solution to quantum process tomography: error analysis and optimal design

arXiv

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arXiv 2024年

作者： Xiao, Shuixin Wang, Yuanlong Zhang, Jun Dong, Daoyi Mooney, Gary J. Petersen, Ian R. Yonezawa, Hidehiro School of Engineering and Technology University of New South Wales CanberraACT2600 Australia University of Michigan–Shanghai Jiao Tong University Joint Institute Shanghai Jiao Tong University Shanghai200240 China School of Engineering The Australian National University CanberraACT2601 Australia Key Laboratory of Systems and Control Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China CIICADA Lab School of Engineering Australian National University ACT2601 Australia School of Physics The University of Melbourne ParkvilleVIC3010 Australia School of Physics University of Melbourne ParkvilleVIC3010 Australia School of Engineering Australian National University ACT2601 Australia RIKEN Center for Quantum Computing Japan Centre for Quantum Computation and Communication Technology Australian Research Council CanberraACT2600 Australia

Quantum process tomography is a critical task for characterizing the dynamics of quantum systems and achieving precise quantum control. In this paper, we propose a two-stage solution for both trace-preserving and non-trace-preserving quantum process tomography. Utilizing a tensor structure, our algorithm exhibits a computational complexity of O(MLd2) where d is the dimension of the quantum system and M, L represent the numbers of different input states and measurement operators, respectively. We establish an analytical error upper bound and then design the optimal input states and the optimal measurement operators, which are both based on minimizing the error upper bound and maximizing the robustness characterized by the condition number. numerical examples and testing on IBM quantum devices are presented to demonstrate the performance and efficiency of our algorithm. Copyright © 2024, The Authors. All rights reserved.

关键词： Error analysis

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Shock Response in Cage-like Polynitrocubane High-Energy-Density Materials: Competition between Strain Energy and Structural Symmetry

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Energetic Materials Frontiers 2025年

作者： Qing-guan Song Li Meng Sheng-li Jiang Lei Zhang Ze-yao Mo Institute of Applied Physics and Computational Mathematics Beijing 100088 China CAEP Software Center for High Performance Numerical Simulation Beijing 100088 China Institute of Chemical Materials China Academy of Engineering Physics Mianyang 621999 China School of Materials Science & Engineering Beijing Institute of Technology Beijing 100081 China State Key Laboratory of Explosion Science and Safety Protection Beijing Institute of Technology Beijing 100081 China

The cage-like structures provide a unique combination of strain energy for enhanced energy storage and hyperstatic constraints to stabilize the system, positioning them as promising pioneers in advancing high-energy-density materials (HEDMs). However, the shock response of cage-like HEDMs is highly complex and exhibits significant variability, posing a grand challenge in the underlying mechanisms. This study reveals that the shock response of cage-like HEDMs is regulated by the interplay between strain energy and structural symmetry, and introduces a physical model to quantitatively describe how they determine shock stability. The investigated systems include a comprehensive series of cage-like polynitrocubane HEDMs, with each carbon atom in the backbone progressively functionalized with nitro groups. Ab initio molecular dynamics (AIMD) simulations were employed to simulate dynamic and kinetic responses at shock velocities ranging from 8 km·s -1 to 11 km·s -1 , with validation provided by consistent Hugoniot curves that align with reported experimental data. Nitro groups at the carbon-based cage structure, recognized as explosion functional groups, were found to substantially increase the system's strain energy. However, an increasing number of nitro groups also intensified electrostatic repulsion among oxygen lone pairs, which weakens structural integrity and renders the material more susceptible to disassembly under shock conditions. Conversely, structural symmetry—including both the cage-like molecular conformation and spatial packing within the crystal lattice—was found to mitigate these destabilizing effects, effectively balancing the trade-off between energy storage and structural stability. Based on these findings, we propose a physical model that captures the essential factors driving shock initiation in cage-like polynitrocubane HEDMs, offering new insights to inform the design and application of novel advanced HEDMs.

关键词： shock stability cage-like high-energy-density materials strain energy structural symmetry strain tensor

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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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Impact analysis of CFAR detection for false targets generated by the phase-switched screen

Impact analysis of CFAR detection for false targets generate...

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

作者： Ran Zhang Yuan S Chen Yu X Zhang Lei Guo Liang J Bai Ping L Zhang National key laboratory of science and technology on test physics and numerical mathematics Beijing institute of Space Long March Vehicle No. 1 Nanda Hongmen Road of Fengtai District Beijing China 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

The phase-switched screen (PSS) has been proved effective in the application of shielding a target or deceiving the radar system when the modulation frequency of it is set greater or smaller than the signal bandwidth. This paper analyses impacts of false targets generated by PSS (PSS-decoys) echoes on radar constant false alarm rate detection. The generation principle of PSS-decoys and the key factors that influence the signatures of PSS-decoys are introduced briefly at first. On base of it, the detection cost caused by the false alarm and false dismissal in a search period of radar is chosen as the criteria of detection performance. The detection costs of CA-CFAR, OS-CFAR, CMLD-CFAR detectors under multiple decoys jamming environment are analysed. Specially, we investigate the influence of the PSS key factors on detection costs from the perspective of simulation. The results show that detection costs will increase remarkably due to false targets existing and it is sensitive to the switching frequency, and the relationship to the duty ratio is tightly relevant to SNR. Among three detectors, the detection costs of CMLD-CFAR detector are higher than that of adopting CA-CFAR and that of adopting OS-CFAR.

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Pathways of Influence of the Northern Hemisphere Mid–high Latitudes on East Asian Climate: A Review

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Advances in Atmospheric sciences 2019年第9期36卷 902-921页

作者： Jianping LI Fei ZHENG Cheng SUN Juan FENG Jing WANG Key Laboratory of Physical Oceanography–Institute for Advanced Ocean Studies Ocean University of China and Qingdao National Laboratory for Marine Science and TechnologyQingdao 266003China College of Global Change and Earth System Science 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

This paper reviews recent progress made by Chinese scientists on the pathways of influence of the Northern Hemisphere mid-high latitudes on East Asian climate within the framework of a“coupled oceanic-atmospheric(land-atmospheric or seaice-atmospheric)bridge”and“chain coupled bridge”.Four major categories of pathways are concentrated upon,as follows:Pathway A—from North Atlantic to East Asia;Pathway B—from the North Pacific to East Asia;Pathway C—from the Arctic to East Asia;and Pathway D—the synergistic effects of the mid-high latitudes and *** addition,definitions of the terms“combined effect”,“synergistic effect”and“antagonistic effect”of two or more factors of influence or processes and their criteria are introduced,so as to objectively investigate those effects in future research.

关键词： East Asian climate Northern Hemisphere mid-high latitudes coupled oceanic-land-sea-ice-atmospheric bridge chain coupled bridge pathway synergistic effect

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