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Self-sustained combustion of CO with transient changes and reaction mechanism over CuCe0.75Zr0.25O delta powder for honeycomb ceramic catalyst 期刊论文  OAI收割
FUEL, 2020, 卷号: 263, 页码: 9
作者:  
Kang RN(康润宁);  Wei XL(魏小林);  Ma PD(马盼东);  Bin F(宾峰);  He JY
  |  收藏  |  浏览/下载:53/0  |  提交时间:2020/04/07
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:60/0  |  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.
  
Changes of Slip Rate and Slip-Plane Orientation by Fault Geometrical Complexities During Fluid Injection 期刊论文  OAI收割
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 2019, 卷号: 124, 期号: 8, 页码: 9226-9246
作者:  
Zhang, Xi;  Wu, Bisheng;  Jeffrey, Robert G.;  Yang, Diansen;  Chen, Weizhong
  |  收藏  |  浏览/下载:32/0  |  提交时间:2020/04/08
Performance test of steel tube enclosed thermistors in air temperature measurements (EI CONFERENCE) 会议论文  OAI收割
3rd International Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2011, January 6, 2011 - January 7, 2011, Shanghai, China
作者:  
Yang H.;  Yan F.;  Yan F.;  Peng J.
收藏  |  浏览/下载:32/0  |  提交时间:2013/03/25
The performances of two steel tube enclosed precision thermistors are tested in a well controlled air environment to determine if the thermistors have enough accuracy for 0.01C levels of air temperature gradient measurement. Three Fluke's 5641 and three 5610 thermistors were tested for 24 hours in Fluke's 7008 calibration bath in the first step. In the second step  the performances of these two thermistors in steady state and transient state air temperature environments were tested for 8 hours separately. The results illustrate that  two of the 5641s were airproofed in a temperature well controlled tube  when steel tube enclosed precision thermistors are used in air temperature measurement  there are unstable departures from each other with a maximum 8.8 mC in constant air medium and 27 mC in temperature changing air medium. The transient-time errors are too large to show the true amounts of temperature changes for air temperature measurement. 2011 IEEE.  
The aircraft autopilot design of parameters changing in a wide range (EI CONFERENCE) 会议论文  OAI收割
2011 International Conference on Electric Information and Control Engineering, ICEICE 2011, April 15, 2011 - April 17, 2011, Wuhan, China
Zhen D.; Yue Z.
收藏  |  浏览/下载:28/0  |  提交时间:2013/03/25
Autopilot is an important part of aircraft  Under the action of the disturbance torque  for the flight parameters of aircraft Changing in a wide range  the range was about 16km  on the basic of analyzing the typical trajectory  the max height was about 5100m  the trajectory of feature points were selected  the deviation of lateral was about 12m  taking pitch control loop for example  the maximum angle of attack was about 3.6  a sub- PID autopilot was designed using classical control theory  the maximum elevator deflection was less than 5  using single-mode Transient suppression method  the maximum aileron deflection was less than 2  the overload due to control surface transition deflection was avoided when control parameters changing  the maximum roll was less than 5  the verification was done by non-linear simulation. The result showed that: the phase margin of autopilot was greater than 30  the response of overload can accurately track the given overload instruction. An autopilot design method of aircraft of parameter changes in a wide range was provided. 2011 IEEE.  the bandwidth was more than 14rad / s  the settling time was less than 0.7s  the maximum overshoot was 23.3%