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The detection, extraction and parameter estimation of extreme-mass-ratio inspirals with deep learning

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 86-96页

作者： Qianyun Yun Wen-Biao Han Yi-yang guo He Wang Minghui Du Hangzhou Institute for Advanced Study University of Chinese Academy of Sciences Shanghai Astronomical Observatory Chinese Academy of Sciences School of Physics and Astronomy Shanghai Jiao Tong University School of Astronomy and Space Science University of Chinese Academy of Sciences Taiji Laboratory for Gravitational Wave Universe (Beijing/Hangzhou) University of Chinese Academy of Sciences Lanzhou Center for Theoretical Physics Key Laboratory of Theoretical Physics of Gansu Province Key Laboratory of Quantum Theory and Applications of MoE Lanzhou University Institute of Theoretical Physics & Research Center of Gravitation Lanzhou University International Centre for Theoretical Physics Asia-Pacific (ICTP-AP) University of Chinese Academy of Sciences (UCAS) Center for Gravitational Wave Experiment National Microgravity Laboratory Institute of Mechanics Chinese Academy of Sciences

One of the primary goals of space-borne gravitational wave detectors is to detect and analyze extreme-mass-ratio inspirals(EMRIs). This task is particularly challenging because EMRI signals are complex, lengthy, and faint. In this work, we introduce a2-layer convolutional neural network(CNN) approach to detect EMRI signals for space-borne detectors, achieving a true positive rate(TPR) of 96.9% at a 1% false positive rate(FPR) for signal-to-noise ratio(SNR) from 50 to 100. Especially, the key intrinsic parameters of EMRIs such as the mass, spin of the supermassive black hole(SMBH) and the initial eccentricity of the orbit can also be inferred directly by employing a neural network. The mass and spin of the SMBH can be determined at 99% and 92% respectively. This will greatly reduce the parameter spaces and computing cost for the following Bayesian parameter *** model also has a low dependency on the accuracy of the waveform model. This study underscores the potential of deep learning methods in EMRI data analysis, enabling the rapid detection of EMRI signals and efficient parameter estimation.

关键词： gravitational wave EMRIs deep-learing

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LPI radar signal detection based on the combination of FFT and segmented autocorrelation plus PAHT

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Journal of Systems Engineering and Electronics 2017年第5期28卷 890-899页

作者： Chengzhi yang Zhiwei Xiong yang guo Bolin Zhang Department of Information Countermeasures Aviation University of Air Force College of Communication Engineering Jilin University Unit 94691 of PLA Unit 94810 of PLA

This paper proposes a desirable method to detect different kinds of low probability of intercept (LPI) radar signals, targeted at the main intra-pulse modulation method of LPI radar signals including the signals of linear frequency modulation, phase code, and frequency code. Firstly, it improves the coherent integration of LPI radar signals by adding the periodicity of the ambiguity function. Then, it develops a frequency domain detection method based on fast Fourier transform (FFT) and segmented autocorrelation function to detect signals without features of linear frequency modulation by virtue of the distribution characteristics of noise signals in the frequency domain. Finally, this paper gives a verification of the performance of the method for different signal-to-noise ratios by conducting simulation experiments, and compares the method with existing ones. Additionally, this method is characterized by the straightforward calculation and high real-time performance, which is conducive to better detecting all kinds of LPI radar signals.

关键词： low probability of intercept (LPI) signal detection period ambiguity function segmented autocorrelation channelization

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Quantum Discord Behavior about Two-Qubit Heisenberg XYZ Model with Decoherence

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Chinese Physics Letters 2014年第3期31卷 18-22页

作者： SONG Le yang guo-Hui School of Physics and Information Engineering Shanxi Normal University Linfen 041004

We investigate the properties of quantum discord dynamics of a two-qubit Heisenberg XYZ system which is influenced by the environmental decoherence under an external nonuniform magnetic field. It shows that the influence of the parameters on the system heavily rely on the selection of the initial states. One point shows that the environmental decoherence cannot entirely destroy the quantum correlation, and properly controlling the parameters can inhibit the decoherence. Moreover, it presents that the inhomogeneous magnetic field cannot affect the steady quantum discord （QD）, while the uniform magnetic field and the anisotropy coupling constant will change the steady QD. These investigations imply that one can obtain larger steady QD values by reasonably adjusting parameters on quantum correlation in solid state systems.

关键词： Magnetic fields

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Expression of Nogo-A mRNA after injury of the rat central nervous system

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Neural Regeneration Research 2008年第12期3卷 1368-1371页

作者： Xigao guo yang guo Tao Huang Department of Neurosurgery the First People＇s Hospital of Shunde Foshan 528300 Guangdong Province China

BACKGROUND： Nogo protein has been identified as an inhibitor of axonal growth, which was highly expressed in central nervous system; however, there are only a few studies on changes of Nogo-A expression following central nervous system injury. OBJECTIVE： To investigate the dynamic expression of Nogo-A mRNA after rat central nervous system injury. DESIGN： Randomized controlled animal study. MATERIALS： Thirty-five rats were randomly divided into two groups, normal animal group （n = 5） and model group （n = 30）. The model group was then divided into six subgroups at six time points： 12, 24 hours and 3, 9, 15, and 21 days post-injury, with five rats in each subgroup. METHODS： The left parietal lobe of rats was contused by free-fall strike, and total RNA was extracted from the entire brain tissue. Semi-quantitative RT-PCR was used to detect Nogo-A mRNA expression, and the ratio between expression of the target gene and glyceraldehyde phosphate dehydrogenase was used to determine the relative expression level. MAIN OUTCOME MEASURES： To determine whether Nogo-A mRNA expression was higher than usual following brain injury. RESULTS： The level of Nogo-A mRNA started to increase 12 hours after injury （P 〈 0.05） and decreased slightly by 24 hours post-injury. Expression increased again on day 3 and reached a peak on day 9. Nogo-A mRNA expression started to decrease on day 15, and then decreased to normal levels at days 21 （P 〉 0.05）. CONCLUSION： After injury of the central nervous system, Nogo-A may play a pivotal role in obstructing regeneration of the nerve.

关键词： central nervous system neural regeneration Nogo-A

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Origin and structures of solar eruptions Ⅰ: Magnetic flux rope

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Science China Earth Sciences 2017年第8期60卷 1383-1407页

作者： CHENG Xin guo yang DING MingDe School of Astronomy and Space Science Nanjing University Key Laboratory for Modern Astronomy and Astrophysics (Nanjing University) Ministry of Education

Coronal mass ejections(CMEs) and solar flares are the large-scale and most energetic eruptive phenomena in our solar system and able to release a large quantity of plasma and magnetic flux from the solar atmosphere into the solar wind. When these high-speed magnetized plasmas along with the energetic particles arrive at the Earth, they may interact with the magnetosphere and ionosphere, and seriously affect the safety of human high-tech activities in outer space. The travel time of a CME to 1 AU is about 1–3 days, while energetic particles from the eruptions arrive even earlier. An efficient forecast of these phenomena therefore requires a clear detection of CMEs/flares at the stage as early as possible. To estimate the possibility of an eruption leading to a CME/flare, we need to elucidate some fundamental but elusive processes including in particular the origin and structures of CMEs/flares. Understanding these processes can not only improve the prediction of the occurrence of CMEs/flares and their effects on geospace and the heliosphere but also help understand the mass ejections and flares on other solar-type stars. The main purpose of this review is to address the origin and early structures of CMEs/flares, from multi-wavelength observational perspective. First of all, we start with the ongoing debate of whether the pre-eruptive configuration, i.e., a helical magnetic flux rope(MFR), of CMEs/flares exists before the eruption and then emphatically introduce observational manifestations of the MFR. Secondly, we elaborate on the possible formation mechanisms of the MFR through distinct ways. Thirdly, we discuss the initiation of the MFR and associated dynamics during its evolution toward the CME/flare. Finally, we come to some conclusions and put forward some prospects in the future.

关键词： Coronal mass ejections Flares Magnetic flux ropes Magnetic field EUV/UV emissions Photosphere Corona Particle acceleration

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Origin and structures of solar eruptions Ⅱ: Magnetic modeling

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Science China Earth Sciences 2017年第8期60卷 1408-1439页

作者： guo yang CHENG Xin DING MingDe School of Astronomy and Space Science Nanjing University Key Laboratory for Modern Astronomy and Astrophysics (Nanjing University) Ministry of Education

The topology and dynamics of the three-dimensional magnetic field in the solar atmosphere govern various solar eruptive phenomena and activities, such as flares, coronal mass ejections, and filaments/prominences. We have to observe and model the vector magnetic field to understand the structures and physical mechanisms of these solar activities. Vector magnetic fields on the photosphere are routinely observed via the polarized light, and inferred with the inversion of Stokes profiles. To analyze these vector magnetic fields, we need first to remove the 180° ambiguity of the transverse components and correct the projection effect. Then, the vector magnetic field can be served as the boundary conditions for a force-free field modeling after a proper preprocessing. The photospheric velocity field can also be derived from a time sequence of vector magnetic ***-dimensional magnetic field could be derived and studied with theoretical force-free field models, numerical nonlinear force-free field models, magnetohydrostatic models, and magnetohydrodynamic models. Magnetic energy can be computed with three-dimensional magnetic field models or a time series of vector magnetic field. The magnetic topology is analyzed by pinpointing the positions of magnetic null points, bald patches, and quasi-separatrix layers. As a well conserved physical quantity,magnetic helicity can be computed with various methods, such as the finite volume method, discrete flux tube method, and helicity flux integration method. This quantity serves as a promising parameter characterizing the activity level of solar active regions.

关键词： Solar activity Solar corona Coronal Mass Ejections(CMEs) Solar flares Magnetic fields Solar photosphere

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A Self-Biased Low-Jitter Process-Insensitive Phase-Locked Loop for 1.25Gb/s-6.25Gb/s SerDes

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Chinese Journal of Electronics 2018年第5期27卷 1009-1014页

作者： YUAN Hengzhou guo yang LIU Yao LIANG Bin guo Qiancheng College of Computer Science National University of Defense Technology

The paper presents a fully integrated multiphase output low-jitter CMOS phase-locked loop for1.25 Gb/s to 6.25 Gb/s wireline Ser Des transmitter clocking. The self-biased bandwidth technology with simplified structure is applied to reduce the sensitivity to process variations. A differential Charge pump(CP) which is suitable for low power supply and process migration is proposed. An accelerator is built to avoid the disadvantage of great damping factor. Self-adaptive frequency dividers are used to improve power efficiency. The simulation results under 65 nm and 55 nm process almost maintain almost the same jitter performance and show the high process insensitivity and good jitter performance.

关键词： Phase-locked loop(PLL) Self-biased Low-jitter Process-insensitive Serializer-deserializer

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Adaptive-surrogate-based robust optimization of transonic natural laminar flow nacelle

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Chinese Journal of Aeronautics 2021年第10期34卷 36-52页

作者： Yuan YAO Dongli MA Muqing yang Liang ZHANG yang guo School of Aeronautic Science and Engineering Beihang UniversityBeijing 100083China

Natural Laminar Flow(NLF)technology is very effective for reducing the skin friction drag of aircraft engine nacelle,but the aerodynamic performance of NLF nacelle is highly sensitive to uncertain working ***,it’s imperative to incorporate uncertainties into the design of NLF *** this study,for a robust optimization of NLF nacelle and for improving its efficiency,an adaptive-surrogate-based robust optimization strategy is established,which is an iterative optimization process where the surrogate model is updated to obtain the real Pareto front of multi-objective optimization problem.A case study is carried out to validate its feasibility and *** results show that the optimization increases the favorable pressure gradient region and the volume ratio of the nacelle by increasing its lip radius and reducing its maximum *** the aerodynamic robustness of the NLF nacelle is mainly determined by the lip radius,maximum diameter of nacelle and location of the maximum *** to the initial nacelle,the optimized nacelle maintains a wide range of low drag and high laminar flow ratio in the disturbance space,which extends the average laminar flow region to 21.6%and facilitates a decrease of 1.98 counts in the average drag coefficient.

关键词： Adaptive surrogate model Aerodynamic robustness Multi-objective optimization Natural laminar flow nacelle Uncertain working conditions

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Preparation of a PTE simulacrum based on surface molecular imprinting

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Chinese Chemical Letters 2011年第4期22卷 493-496页

作者： Yong guo Ying yang Tian Ying guo Key Laboratory of Functional Polymer Materials Ministry of Education Institute of Polymer Chemistry Nankai University Tianjin 300071 China

Firstly,we synthesized N-methacryloyl-histidine monomer and N-methacryloyl-histidine-Cu^2＋ complex（MAH-Cu^2＋）.Then the molecular imprinting polymers（MIP） has been prepared by surface grafting on uniform polystyrene（PS） core using reversible addition-fragmentation transfer polymerization（RAFT） with MAH-Cu^2＋ as the functional monomer,methyl paraoxon as the template to simulate phosphodiesterase（PTE）.Finally,we have investigated the catalytic hydrolytic activities of MIP and non-imprinting polymers（NIP） to the template methyl paraoxon and the template analogue ethyl paraoxon respectively by UV *** results showed that the catalytic hydrolytic activity of MIP to the template methyl paraoxon was highest and the value of k is 8.67×10^-5 mmol L^-1 min^-1,3.89-fold higher than MIP to the template analogue ethyl paraoxon,2.79-fold higher than NIP to the template methyl *** KM,rm of MSP are also determined,and KM = 3.95×10^-4）mol/L,rm = 2.12μmol/ *** MIP can be reused with only lose 7%of catalytic activity for four cycles.

关键词： Molecular imprinting Surface grafting Catalytic hydrolysis Paraoxon

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Synthesis and Crystal Structure of 3-(2-Hydroxybenzly)-4-(4-Hydroxybenzylideneamino)-(1H) -1,2,4-Triazole-5-Thione and Its Antibacterial Activities

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Chinese Journal of Structural Chemistry 2005年第12期24卷 1403-1407页

作者： yang Jian-guo PAN Fu-You Office of Assets Administration Taizhou University Zhejiang 317000 China Department of Chemistry Taizhou University Zhejiang 317000 China

The title compound C15H12N4O2S was synthesized by the reaction of 3-（2-hydroxybenzyl）-4-amino-（1H）-1,2,4-triazole-5-thione with 4-hydroxybenzaldehyde in ethanol and characterized by IR, ^1H NMR spectra and elemental analysis. Its structure has been determined by X-ray diffraction analysis. The crystal belongs to monoclinic, space group C2/c with a = 27.990（3）, b = 13.1326（14）, c = 7.9770（8） A, β= 105.787（2）°, V = 2821.6（5）A^3, Z = 8, Mr= 312.35,μ= 0.243 mm^-1, Dc = 1.471 g/cm^3 and F（000） = 1296. The structure was solved by direct *** refined to a Rint value of 0.0388. The crystal structure involving in intermolecular N-H…S and O-H…S hydrogen bonds is observed, meanwhile intramolecular O-H…N hydrogen bond is also found. Their biological activities have been measured. The results show that this type of compound has certain antibacterial activity for Staphylococous aureus and Bacillus subtilis.

关键词： 1,2,4-triazole-5-thione X-ray diffraction crystal structure,synthesis antibacterial activities

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