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The Divergent Changes in Surface Water Area after the South-to-North Water Diversion Project in China 期刊论文  OAI收割
REMOTE SENSING, 2024, 卷号: 16, 期号: 2, 页码: 27
作者:  
Guo, Tongze;  Li, Runkui;  Xiao, Zhen;  Cai, Panli;  Guo, Jingxian
  |  收藏  |  浏览/下载:27/0  |  提交时间:2024/03/01
Evapotranspiration as a response to climate variability and ecosystem changes in southwest, China 期刊论文  OAI收割
ENVIRONMENTAL EARTH SCIENCES, 2020, 卷号: 79, 期号: 12, 页码: 21
作者:  
Mokhtar, Ali;  He, Hongming;  Alsafadi, Karam;  Li, Yu;  Zhao, Hongfei
  |  收藏  |  浏览/下载:49/0  |  提交时间:2021/07/09
An underlying clock in the extreme flip-flop state transitions of the black hole transient Swift J1658.2-4242 期刊论文  OAI收割
Astronomy and Astrophysics, 2020, 卷号: 641, 页码: A101
作者:  
HXMT
  |  收藏  |  浏览/下载:65/0  |  提交时间:2022/02/08
accretion  accretion disks  black hole physics  X-rays: binaries  time  Astrophysics - High Energy Astrophysical Phenomena  Abstract:
Aims: Flip-flops are top-hat-like X-ray flux variations, which have been observed in some transient accreting black hole binary systems, and feature simultaneous changes in the spectral hardness and the power density spectrum (PDS). They occur at a crucial time in the evolution of these systems, when the accretion disc emission starts to dominate over coronal emission. Flip-flops remain a poorly understood phenomenon, so we aim to thoroughly investigate them in a system featuring several such transitions.
Methods: Within the multitude of observations of Swift J1658.2-4242 during its outburst in early 2018, we detected 15 flip-flops, enabling a detailed analysis of their individual properties and the differences between them. We present observations by XMM-Newton, NuSTAR, Astrosat, Swift, Insight-HXMT, INTEGRAL, and ATCA. We analysed their light curves, searched for periodicities, computed their PDSs, and fitted their X-ray spectra, to investigate the source behaviour during flip-flop transitions and how the interval featuring flip-flops differs from the rest of the outburst.
Results: The flip-flops of Swift J1658.2-4242 are of an extreme variety, exhibiting flux differences of up to 77% within 100 s, which is much larger than what has been seen previously. We observed radical changes in the PDS simultaneous with the sharp flux variations, featuring transitions between the quasi-periodic oscillation types C and A, which have never been observed before. Changes in the PDS are delayed, but more rapid than changes in the light curve. Flip-flops occur in two intervals within the outburst, separated by about two weeks in which these phenomena were not seen. Transitions between the two flip-flop states occurred at random integer multiples of a fundamental period of 2.761 ks in the first interval and 2.61 ks in the second. Spectral analysis reveals the high and low flux flip-flop states to be very similar, but distinct from intervals lacking flip-flops. A change of the inner temperature of the accretion disc is responsible for most of the flux difference in the flip-flops. We also highlight the importance of correcting for the influence of the dust scattering halo on the X-ray spectra.
  
Warming Effects on Ecosystem Carbon Fluxes Are Modulated by Plant Functional Types 期刊论文  OAI收割
ECOSYSTEMS, 2017, 卷号: 20, 期号: 3, 页码: 515-526
作者:  
Huang, Rujin;  Estera, Katerina Y.;  Niu, Shuli;  Jiang, Lifen;  Zhou, Xuhui
  |  收藏  |  浏览/下载:124/0  |  提交时间:2018/10/16
Combined effects of climate, restoration measures and slope position in change in soil chemical properties and nutrient loss across lands affected by the Wenchuan Earthquake in China 期刊论文  OAI收割
Science of the Total Environment, 2017, 卷号: 596-597, 页码: 274-283
作者:  
Lin, Yongming;  Deng, Haojun;  Du, Kun;  Rafay, Loretta;  Zhang, Guang-shuai
收藏  |  浏览/下载:37/0  |  提交时间:2017/05/08
Spatiotemporal Variation of Driving Forces for Settlement Expansion in Different Types of Counties SCI/SSCI论文  OAI收割
2016
作者:  
Dong G. L.;  Xu, E. Q.;  Zhang, H. Q.
  |  收藏  |  浏览/下载:34/0  |  提交时间:2017/11/09
Spatiotemporal Variation of Driving Forces for Settlement Expansion in Different Types of Counties SCI/SSCI论文  OAI收割
2016
作者:  
Dong G. L.;  Xu, E. Q.;  Zhang, H. Q.
收藏  |  浏览/下载:28/0  |  提交时间:2016/12/16
From plant functional types to plant functional traits: A new paradigm in modelling global vegetation dynamics 期刊论文  OAI收割
PROGRESS IN PHYSICAL GEOGRAPHY, 2015, 卷号: 39, 期号: 4, 页码: 514-535
作者:  
Yang, Yanzheng;  Zhu, Qiuan;  Peng, Changhui;  Wang, Han;  Chen, Huai
  |  收藏  |  浏览/下载:23/0  |  提交时间:2020/03/25
Mapping dynamic cover types in a large seasonally flooded wetland using extended principal component analysis and object-based classification 期刊论文  OAI收割
REMOTE SENSING OF ENVIRONMENT, 2015, 卷号: 158, 页码: 270-283
作者:  
Dronova, Iryna;  Gong, Peng;  Wang, Lin;  Zhong, Liheng
收藏  |  浏览/下载:48/0  |  提交时间:2016/04/20