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Timing analysis of Swift J1658.2-4242's outburst in 2018 with Insight-HXMT, NICER and AstroSat 期刊论文  OAI收割
Journal of High Energy Astrophysics, 2019, 卷号: 24, 页码: 30-40
作者:  
HXMT
  |  收藏  |  浏览/下载:57/0  |  提交时间:2022/02/08
Accretion  accretion disks  Black hole physics  X-rays: binaries:  Swift J1658.2-4242  Astrophysics - High Energy Astrophysical Phenomena  Abstract: We present the observational results from a detailed timing analysis of the black hole candidate Swift J1658.2-4242 during its 2018 outburst with the observations of Hard X-ray Modulation Telescope (Insight-HXMT), Neutron Star Interior Composition Explorer (NICER) and AstroSat in 0.1-250 keV. The evolution of intensity, hardness and integrated fractional root mean square (rms) observed by Insight-HXMT and NICER are presented in this paper. Type-C quasi-periodic oscillations (QPOs) observed by NICER (0.8-3.5 Hz) and Insight-HXMT (1-1.6 Hz) are also reported in this work. The features of the QPOs are analyzed with an energy range of 0.5-50 keV. The relations between QPO frequency and other characteristics such as intensity, hardness and QPO rms are carefully studied. The timing and spectral properties indicate that Swift J1658.2-4242 is a black hole binary system. Besides, the rms spectra of the source calculated from the simultaneous observation of Insight-HXMT, NICER and AstroSat support the Lense-Thirring origin of the QPOs. The relation between QPO phase lag and the centroid frequency of Swift J1658.2-4242 reveals a near zero constant when < 4Hz and a soft phase lag at 6.68 Hz. This independence follows the same trend as the high inclination galactic black hole binaries such as MAXI J1659-152.  
Carbon content and climate variability drive global soil bacterial diversity patterns 期刊论文  OAI收割
ECOLOGICAL MONOGRAPHS, 2016, 卷号: 86, 期号: 3, 页码: 373-390
作者:  
Osanai, Yui;  Liu, Yu-Rong;  Hamonts, Kelly;  Jeffries, Thomas C.;  Singh, Brajesh K.
  |  收藏  |  浏览/下载:32/0  |  提交时间:2017/04/05
Classification of small-scale eucalyptus plantations based on NDVI time series obtained from multiple high-resolution datasets 期刊论文  OAI收割
Remote Sensing, 2016, 卷号: 8, 期号: 2
作者:  
Qiao, Hailang;  Wu, Mingquan;  Shakir, Muhammad;  Wang, Li;  Kang, Jun
收藏  |  浏览/下载:32/0  |  提交时间:2017/04/24
Effects of Pore-Size Range and Composition of Polysaccharide Gels on Flow Behaviors and Selective Sorting of Single-Walled Carbon Nanotubes 期刊论文  OAI收割
ACTA PHYSICO-CHIMICA SINICA, 2014, 卷号: 30, 期号: 9, 页码: 1764-1770
作者:  
Jin HH(金赫华)
收藏  |  浏览/下载:25/0  |  提交时间:2014/12/01
Gradient Structure-Induced Temperature Responsiveness in Styrene/Methyl Methacrylate Gradient Copolymers Micelles 期刊论文  OAI收割
macromolecular rapid communications, 2014, 卷号: 35, 期号: 3, 页码: 309-316
Zheng,Chao; Huang,Haiying; He,Tianbai
收藏  |  浏览/下载:24/0  |  提交时间:2015/10/15
In this work  micelles are formed by gradient copolymer of styrene and methyl methacrylate in acetone-water mixture and their temperature responsiveness is investigated in a narrow range near room temperature. Three different kinds of structural transitions could be induced by temperature: unimers to micelle transition  shrinkage/stretching of micelles  and morphological transition from spherical micelles to vesicles. In addition  a model analysis on the interface of gradient copolymer micelle is made to better understand these phenomena. It is found that both position and composition of the interface could alter in response to the change in temperature. According to the experiments and model analysis  it is proposed that temperature responsiveness might be an intrinsic and universal property of gradient copolymer micelles  which only originates from the gradient structure.  
Forest Biodiversity Assessment in Peruvian Andean Montane Cloud Forest 期刊论文  OAI收割
Journal of Mountain Science, 2012, 卷号: 9, 期号: 3, 页码: 372-384
Alicia Ledo; Sonia Condés; Iciar Alberdi
收藏  |  浏览/下载:34/0  |  提交时间:2013/04/16
Design of motion compensation mechanism of satellite remote sensing camera (EI CONFERENCE) 会议论文  OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Space Exploration Technologies and Applications, May 24, 2011 - May 26, 2011, Beijing, China
Gu S.; Yan Y.; Xu K.; Jin G.
收藏  |  浏览/下载:48/0  |  提交时间:2013/03/25
With the development of aerospace remote sensing technology  the ground resolution of remote sensing camera enhances continuously. Since there is relative motion between camera and ground target when taking pictures  the target image recorded in recording media is moved and blurred. In order to enhance the imaging quality and resolution of the camera  the image motion had to be compensated. In order to abate the effect of image motion to image quality of space camera and improve the resolution of the camera  the compensation method of image motion to space camera is researched. First  the reason of producing drift angle and adjustment principle are analyzed in this paper. This paper introduce the composition and transmission principle of image motion compensation mechanism. Second  the system adopts 80C31 as controller of drift angle  and adopts stepping motor for actuators  and adopts absolute photoelectric encoder as the drift Angle measuring element. Then the control mathematical model of the image motion compensation mechanism are deduced  and it achieve the closed-loop control of the drift angle position. At the last  this paper analyses the transmission precision of the mechanism. Through the experiment  we measured the actual precision of the image motion compensation mechanism  and compared with the theoretical analysis. There are two major contributions in this paper. First  the traditional image motion compensation mechanism is big volume and quality heavy. This has not fit for the development trend of space camera miniaturization and lightweight. But if reduce the volume and quality of mechanism  it will bring adverse effects for the precision and stiffness of mechanism. For this problem  This paper designed a image motion compensation that have some advantages such as small size  light weight at the same time  high precision  stiffness and so on. This image motion compensation can be applicable to the small optics cameras with high resolution. Second  the traditional mechanism control need to corrected  fitting and iterative for the control formula of mechanism. Only in this way  we can get the optimal control mathematical model. This paper has high precision of the control formula derived. It can achieve the high precision control without fitting  It also simplify the difficulty of control mathematical model establishment. This paper designed the range of adjusting of image motion compensation mechanism between -5 +5. Based on choosing-5  -4  -3  -2  -1  0  +1  +2  +3  +4  +4 as the expectation value of the imaginary drift angle  we get ten groups of the fact data in adjusting drift angle measured. The test results show that the precision of the drift angle control system can be achieved in 1. It can meet the system requirements that the precision of the control system is less than 3'  and it can achieve the high-precision image motion compensation. 2011 SPIE.  
Dependence of critical condition in liquid chromatography on the pore size of column substrates 期刊论文  OAI收割
polymer, 2011, 卷号: 52, 期号: 14, 页码: 3219-3225
Zhu YT; Ziebarth JD; Wang YM
收藏  |  浏览/下载:22/0  |  提交时间:2012/06/11
Transport of semivolatile organic compounds to the Tibetan Plateau: Monthly resolved air concentrations at Nam Co 期刊论文  OAI收割
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2010, 卷号: 115, 期号: D16310
作者:  
Kang SC(康世昌);  Zhang QG(张强弓)
收藏  |  浏览/下载:28/0  |  提交时间:2011/04/26
Research on method of measuring the time of remote explosion point (EI CONFERENCE) 会议论文  OAI收割
27th International Congress on High-Speed Photography and Photonics, September 17, 2006 - September 22, 2006, Xi'an, China
作者:  
Zhou J.;  Fu Y.
收藏  |  浏览/下载:22/0  |  提交时间:2013/03/25