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Synchronous X-ray/Optical QPOs from the Black Hole LMXB MAXI J1820+070 期刊论文 OAI收割
Monthly Notices of the Royal Astronomical Society, 2021
作者: HXMT

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收藏 | 浏览/下载：53/0 | 提交时间：2022/02/08

black hole physics Low Mass X-ray Binaries accretion accretion discs stars: individual (MAXI J1820+070) Astrophysics - High Energy Astrophysical Phenomena Abstract: We present high-speed optical photometry from SAAO and SALT on the black hole LMXB MAXI J1820+070 (ASSASN-18ey), some of it simultaneous with NICER, Swift and Insight-HXMT X-ray coverage. We detect optical Quasi-Periodic Oscillations (QPOs) that move to higher frequencies as the outburst progresses, tracking both the frequency and evolution of similar X-ray QPOs previously reported. Correlated X-ray/optical data reveal a complex pattern of lags, including an anti-correlation and a sub-second lag that evolve over the first few weeks of outburst. They also show correlated components separated by a lag equal to the QPO period roughly centered on zero lag, implying that the inter-band variability is strongly and consistently affected by these QPOs at a constant phase lag of roughly ±Ю The synchronisation of X-ray and optical QPOs indicates that they must be produced in regions physically very close to each other we thus propose that they can be explained by a precessing jet model, based on analogies with V404 Cyg and MAXI J1348-630.

A Novel Radius Adaptive Based on Center-Optimized Hybrid Detector Generation Algorithm 期刊论文 OAI收割
IEEE/CAA Journal of Automatica Sinica, 2020, 卷号: 7, 期号: 6, 页码: 1627-1637
作者: Jinyin Chen

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收藏 | 浏览/下载：23/0 | 提交时间：2021/03/11

Artificial immunity center optimized hybrid detect negative detector negative selection algorithm (NSA) radius adaptive

Constraining the X-Ray-Infrared Spectral Index of Second-timescale Flares from SGR 1935+2154 with Palomar Gattini-IR 期刊论文 OAI收割
The Astrophysical Journal, 2020, 卷号: 901, 页码: L7
作者: HXMT

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收藏 | 浏览/下载：24/0 | 提交时间：2022/02/08

Radio transient sources Magnetars Soft gamma-ray repeaters 2008 992 1471 Astrophysics - High Energy Astrophysical Phenomena Astrophysics - Instrumentation and Methods for Astrophysics Abstract: The Galactic magnetar SGR 1935+2154 has been reported to produce the first example of a bright millisecond-duration radio burst (FRB 200428) similar to the cosmological population of fast radio bursts (FRBs). The detection of a coincident bright X-ray burst represents the first observed multiwavelength counterpart of an FRB. However, the search for similar emission at optical wavelengths has been hampered by the high inferred extinction on the line of sight. Here, we present results from the first search for second-timescale emission from the source at near-infrared (NIR) wavelengths using the Palomar Gattini-IR observing system in the J band, enabled by a novel detector readout mode that allows short exposure times of ?0.84 s with 99.9% observing efficiency. With a total observing time of ?12 hr (?47,728 images) during its 2020 outburst, we place median 3Ҡlimits on the second-timescale NIR fluence of ?18 Jy ms (13.1 AB mag). The corresponding extinction-corrected limit is ?125 Jy ms for an estimated extinction of A_J = 2.0 mag. Our observations were sensitive enough to easily detect an NIR counterpart of FRB 200428 if the NIR emission falls on the same power law as observed across its radio to X-ray spectrum. We report nondetection limits from epochs of four simultaneous X-ray bursts detected by the Insight-HXMT and NuSTAR telescopes during our observations. These limits provide the most stringent constraints to date on fluence of flares at 10¹⁴ Hz, and constrain the fluence ratio of the NIR emission to coincident X-ray bursts to R_NIR ? 0.025 (fluence index ?0.35).

Unit panel node detection by CNN on FAST reflector 期刊论文 OAI收割
RESEARCH IN ASTRONOMY AND ASTROPHYSICS, 2019, 卷号: 19, 期号: 1, 页码: 10
作者: Zhang, Zhi-Song; Zhu, Li-Chun; Tang, Wei; Li, Xin-Yi

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收藏 | 浏览/下载：16/0 | 提交时间：2020/03/10

telescopes FAST photogrammetry nodes detect convolutional neural network

Radar detection of fluctuating targets under heavy-tailed clutter using track-before-detect 期刊论文 OAI收割
Sensors (Switzerland), 2018, 卷号: 18, 期号: 7, 页码: 1-13
作者: Du JS(杜劲松); Gao J(高洁); Wang W(王伟); Zhou XF(周晓锋); Zhou XF(周晓锋)

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收藏 | 浏览/下载：43/0 | 提交时间：2018/08/08

target detection radar systems K-distributed clutter heavy-tailed Swerling target track-before-detect (TBD)

Radar detection of fluctuating targets under heavy-tailed clutter using track-before-detect 期刊论文 OAI收割
SENSORS, 2018, 卷号: 18, 期号: 7, 页码: 1-13
作者: Gao J(高洁); Du JS(杜劲松); Wang W(王伟)

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收藏 | 浏览/下载：60/0 | 提交时间：2018/08/08

Target Detection Radar Systems K-distributed Clutter Heavy-tailed Swerling Target Track-before-detect (Tbd)

Psi(2s) decay to j/psi(1s)+2 pi or j/psi(1s) plus sigma+2 pi 期刊论文 iSwitch采集
International journal of theoretical physics, 2017, 卷号: 56, 期号: 3, 页码: 942-947
作者: Kisslinger, Leonard S.; Zhou Li-juan; Ma Wei-xing; Shen, Pengnian

收藏 | 浏览/下载：30/0 | 提交时间：2019/04/23

Hybrid mesons Heavy quark state decay Detect sigma Glueball

Psi(2S) Decay to J/Psi(1S)+2 pi or J/Psi(1S) plus sigma+2 pi 期刊论文 OAI收割
INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS, 2017, 卷号: 56, 期号: 3, 页码: 942-947
作者: Zhou, LJ; Kisslinger, LS; Ma WX(马维兴); Shen, PN; Ma, WX

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收藏 | 浏览/下载：21/0 | 提交时间：2019/08/27

Hybrid mesons Heavy quark state decay Detect sigma Glueball

Psi(2S) Decay to J/Psi(1S)+2 pi or J/Psi(1S) plus sigma+2 pi 期刊论文 OAI收割
INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS, 2017, 卷号: 56, 期号: 3, 页码: 942-947
作者: Kisslinger, LS; Zhou, LJ; Ma WX(马维兴); Shen PN(沈彭年); Ma, WX

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收藏 | 浏览/下载：20/0 | 提交时间：2019/08/29

Hybrid mesons Heavy quark state decay Detect sigma Glueball

A Finite Element Model to Simulate Defect Formation during Friction Stir Welding 期刊论文 OAI收割
METALS, 2017, 卷号: 7, 期号: 7, 页码: 1-15
作者: Wu ZQ(吴振强); Wang M(王敏); Yu T(于涛); Zhang X(张骁); Zhang HJ(张会杰)

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收藏 | 浏览/下载：58/0 | 提交时间：2017/09/12

friction stir welding Al6061-T6 material flow welding detect finite element simulation coupled Eulerian Lagrangian