|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | The FAST Galactic Plane Pulsar Snapshot survey:I.Project design and pulsar discoveries显示文摘Discovery of pulsars is one of the main goals for large radio telescopes.The Five-hundredmeter Aperture Spherical radio Telescope(FAST),that incorporates an L-band 19-beam receiver with a system temperature of about 20 K,is the most sensitive radio telescope utilized for discovering pulsars.We designed the snapshot observation mode for a FAST key science project,the Galactic Plane Pulsar Snapshot(GPPS)survey,in which every four nearby pointings can observe a cover of a sky patch of 0.1575 square degrees through beam-switching of the L-band 19-beam receiver.The integration time for each pointing is 300 seconds so that the GPPS observations for a cover can be made in 21 minutes.The goal of the GPPS survey is to discover pulsars within the Galactic latitude of±10∘from the Galactic plane,and the highest priority is given to the inner Galaxy within±5∘.Up to now,the GPPS survey has discovered 201 pulsars,including currently the faintest pulsars which cannot be detected by other telescopes,pulsars with extremely high dispersion measures(DMs)which challenge the currently widely used models for the Galactic electron density distribution,pulsars coincident with supernova remnants,40 millisecond pulsars,16 binary pulsars,some nulling and mode-changing pulsars and rotating radio transients(RRATs).The follow-up observations for confirmation of new pulsars have polarization-signals recorded for polarization profiles of the pulsars.Re-detection of previously known pulsars in the survey data also leads to significant improvements in parameters for 64 pulsars.The GPPS survey discoveries are published and will be updated at http://zmtt.bao.ac.cn/GPPS/. | J.L.Han Chen Wang P.F.Wang Tao Wang D.J.Zhou Jing-Hai Sun Yi Yan Wei-Qi Su Wei-Cong Jing Xue Chen X.Y.Gao Li-Gang Hou Jun Xu K.J.Lee Na Wang Peng Jiang Ren-Xin Xu Jun Yan Heng-Qian Gan Xin Guan Wen-Jun Huang Jin-Chen Jiang Hui Li Yun-Peng Men Chun Sun Bo-Jun Wang H.G.Wang Shuang-Qiang Wang Jin-Tao Xie Heng Xu Rui Yao Xiao-Peng You D.J.Yu Jian-Ping Yuan Rai Yuen Chun-Feng Zhang Yan Zhu | 2021 | Research in Astronomy and Astrophysics2021，21，5： | 4 |
| 2 | Acoustic Emission Monitoring and Microscopic Investigation of Cracks in ERCuNi Cladding显示文摘A corrosion resistant CuNi cladding was deposited on SM45C (equivalent to AI5I1045) substrate by DC inverse arcwelding. During the welding process, a three channel acoustic emission (AE) monitoring system was applied to detectthe crack signals generating from both the cladding process and after cladding. Characteristics of the welding cracksignal and noise signal had been analyzed systematically. Based on the record time of the signal, the solidificationcrack and delayed crack were distinguished. By two-dimensional AE source location, the crack position was located,and then investigated by scanning electron microscopy (SEM). Results showed that the AE system could detect thewelding crack with high sensitivity and the two-dimensional source location could accurately determine the crackposition. Microstructures of the cladding and heat affected zone (HAZ) were examined. Dendrites in the claddingand coarse grains in the HAZ were found. | S.P.Lu O.Y.Kwon K.J.Lee T.B.Kim | 2003 | Journal of Materials Science & Technology2003，19，3： | 1 |
| 3 | Bipolar fuzzy subalgebras and bipolar fuzzyideals of BCK/BCI-algebras显示文摘 | K.J.LEE | | 0，，03： | 1 |
| 4 | Joint optimization for one and two-way MIMO AF multiple-relay systems显示文摘 | K.J.Lee H.Sung E.Park | | 0，，12： | 1 |
| 5 | 查看详情显示文摘 | M.H.Han S.Lee N.J.Kim K.J.Lee T.Chung G.Byun | | 0，，： | 1 |
| 6 | FAST Observations of an Extremely Active Episode of FRB 20201124A:Ⅰ.Burst Morphology显示文摘We report the properties of more than 600 bursts(including cluster-bursts)detected from the repeating fast radio burst(FRB)source FRB 20201124A with the Five-hundred-meter Aperture Spherical radio Telescope during an extremely active episode on UTC 2021 September 25–28,in a series of four papers.The observations were carried out in the band of 1.0–1.5 GHz by using the center beam of the L-band 19-beam receiver.We monitored the source in sixteen1 hr sessions and one 3 hr session spanning 23 days.All the bursts were detected during the first four days.In this first paper of the series,we perform a detailed morphological study of 624 bursts using the two-dimensional frequencytime“waterfall”plots,with a burst(or cluster-burst)defined as an emission episode during which the adjacent emission peaks have a separation shorter than 400 ms.The duration of a burst is therefore always longer than 1 ms,with the longest up to more than 120 ms.The emission spectra of the sub-bursts are typically narrow within the observing band with a characteristic width of~277 MHz.The center frequency distribution has a dominant peak at about 1091.9 MHz and a secondary weak peak around 1327.9 MHz.Most bursts show a frequencydownwarddrifting pattern.Based on the drifting patterns,we classify the bursts into five main categories:downward drifting(263)bursts,upward drifting(3)bursts,complex(203),no drifting(35)bursts,and no evidence for drifting(121)bursts.Subtypes are introduced based on the emission frequency range in the band(low,middle,high and wide)as well as the number of components in one burst(1,2,or multiple).We measured a varying scintillation bandwidth from about 0.5 MHz at 1.0 GHz to 1.4 MHz at 1.5 GHz with a spectral index of 3.0. | D.J.Zhou J.L.Han B.Zhang K.J.Lee W.W.Zhu D.Li W.C.Jing W.-Y.Wang Y.K.Zhang J.C.Jiang J.R Niu R Luo H.Xu C.F.Zhang B.J.Wang J.W.Xu P.Wang Z.L.Yang Y.Feng | 2022 | Research in Astronomy and Astrophysics2022，22，12： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员