To solve the problem of insufficient ability when detecting the high-speed moving target with passive millimeter wave technology, a direct-detection passive millimeter wave detecting system using the monolithic microw...To solve the problem of insufficient ability when detecting the high-speed moving target with passive millimeter wave technology, a direct-detection passive millimeter wave detecting system using the monolithic microwave integrated cir- cuit （MMIC） millimeter wave radiometer is built, and the measured data are obtained by experiment under different condi- tions. Based on feature analysis of testing signals, it points out that the peak of the first pulse and interval of two peak pulses are valid features which can reflect the motion characteristic of target. A method to calculate the moving speed of target is put forward. The calculating results indicate that the proposed method has enough accuracy and is feasible to determine the parameters of the moving target using for passive millimeter wave system.展开更多
Gravitational wave detection has ushered in a new era of observing the universe, providing humanity with a novel window for cosmic cognition. This theoretical study systematically traces the developmental trajectory o...Gravitational wave detection has ushered in a new era of observing the universe, providing humanity with a novel window for cosmic cognition. This theoretical study systematically traces the developmental trajectory of gravitational wave detection technology and delves into its profound impact on cosmological research. From Einstein’s prediction in general relativity to LIGO’s groundbreaking discovery, the article meticulously delineates the key theoretical and technological milestones in gravitational wave detection, with particular emphasis on elucidating the principles and evolution of core detection technologies such as laser interferometers. The research thoroughly explores the theoretical application value of gravitational waves in verifying general relativity, studying the physics of compact celestial bodies like black holes and neutron stars, and precisely measuring cosmological parameters. The article postulates that gravitational wave observations may offer new research perspectives for addressing cosmological conundrums such as dark matter, dark energy, and early universe evolution. The study also discusses the scientific prospects of combining gravitational wave observations with electromagnetic waves, neutrinos, and other multi-messenger observations, analyzing the potential value of this multi-messenger astronomy in deepening cosmic cognition. Looking ahead, the article examines cutting-edge concepts such as space-based gravitational wave detectors and predicts potential developmental directions for gravitational wave astronomy. This research not only elucidates the theoretical foundations of gravitational wave detection technology but also provides a comprehensive theoretical framework for understanding the far-reaching impact of gravitational waves on modern cosmology.展开更多
To evaluate the quality and damage condition of the electrolyzer,wave velocity detection technology and impact echo technology were used to detect the cathode part of the electrolyzer.The experimental results show tha...To evaluate the quality and damage condition of the electrolyzer,wave velocity detection technology and impact echo technology were used to detect the cathode part of the electrolyzer.The experimental results show that wave velocity is linearly related to the porosity,and there is also a linear relationship between wave velocity and the square root of reciprocal density in cathode carbon blocks(CCBs)before installation into electrolyzer.Combined with detection results of wave velocity and voltage drop,the large-size CCBs with relatively good quality can be found.Through the impact echo technology on cathode steel rods(CSRs),the results of the on-site detection show that the damage condition of CSRs can be effectively evaluated,and the damage location of CSRs can be determined.This study proposes a novel and quantifiable method for the evaluation of cathode quality and damage,which provides a reference for prolonging the service life of the electrolyzer.展开更多
文摘To solve the problem of insufficient ability when detecting the high-speed moving target with passive millimeter wave technology, a direct-detection passive millimeter wave detecting system using the monolithic microwave integrated cir- cuit （MMIC） millimeter wave radiometer is built, and the measured data are obtained by experiment under different condi- tions. Based on feature analysis of testing signals, it points out that the peak of the first pulse and interval of two peak pulses are valid features which can reflect the motion characteristic of target. A method to calculate the moving speed of target is put forward. The calculating results indicate that the proposed method has enough accuracy and is feasible to determine the parameters of the moving target using for passive millimeter wave system.
文摘Gravitational wave detection has ushered in a new era of observing the universe, providing humanity with a novel window for cosmic cognition. This theoretical study systematically traces the developmental trajectory of gravitational wave detection technology and delves into its profound impact on cosmological research. From Einstein’s prediction in general relativity to LIGO’s groundbreaking discovery, the article meticulously delineates the key theoretical and technological milestones in gravitational wave detection, with particular emphasis on elucidating the principles and evolution of core detection technologies such as laser interferometers. The research thoroughly explores the theoretical application value of gravitational waves in verifying general relativity, studying the physics of compact celestial bodies like black holes and neutron stars, and precisely measuring cosmological parameters. The article postulates that gravitational wave observations may offer new research perspectives for addressing cosmological conundrums such as dark matter, dark energy, and early universe evolution. The study also discusses the scientific prospects of combining gravitational wave observations with electromagnetic waves, neutrinos, and other multi-messenger observations, analyzing the potential value of this multi-messenger astronomy in deepening cosmic cognition. Looking ahead, the article examines cutting-edge concepts such as space-based gravitational wave detectors and predicts potential developmental directions for gravitational wave astronomy. This research not only elucidates the theoretical foundations of gravitational wave detection technology but also provides a comprehensive theoretical framework for understanding the far-reaching impact of gravitational waves on modern cosmology.
基金The authors are grateful for the financial supports from the National Natural Science Foundation of China(No.42172316)the Natural Science Foundation of Hunan Province,China(No.2021JJ30810)the Research Fund of the State Key Laboratory of Coal Resources and Safe Mining,China(No.CUMT SKLCRSM21KF005).
文摘To evaluate the quality and damage condition of the electrolyzer,wave velocity detection technology and impact echo technology were used to detect the cathode part of the electrolyzer.The experimental results show that wave velocity is linearly related to the porosity,and there is also a linear relationship between wave velocity and the square root of reciprocal density in cathode carbon blocks(CCBs)before installation into electrolyzer.Combined with detection results of wave velocity and voltage drop,the large-size CCBs with relatively good quality can be found.Through the impact echo technology on cathode steel rods(CSRs),the results of the on-site detection show that the damage condition of CSRs can be effectively evaluated,and the damage location of CSRs can be determined.This study proposes a novel and quantifiable method for the evaluation of cathode quality and damage,which provides a reference for prolonging the service life of the electrolyzer.
