中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
首页 机构 成果 学者
  
  1. CAS IR Grid
机构
采集方式
内容类型
发表日期
学科主题
筛选

浏览/检索结果: 共9条，第1-9条 帮助

条数/页： 排序方式：
An alternative numerical method for calculating C* parameter under mode I loading utilizing rate-dependent energy release rate 期刊论文  OAI收割
THEORETICAL AND APPLIED FRACTURE MECHANICS, 2020, 卷号: 109, 页码: 102737
作者:  Du XH;  Dai YW;  Han Q;  Liu YH;  Cao P
  |  收藏  |  浏览/下载：57/0  |  提交时间：2020/12/28
Estimation of C*-Integral for Central Cracked Plate Under Biaxial Loading 期刊论文  OAI收割
INTERNATIONAL JOURNAL OF APPLIED MECHANICS, 2020, 卷号: 12, 期号: 7, 页码: 2050079
作者:  Dai YW;  Qin F;  Liu YH;  Feng WZ;  Qian GA(钱桂安)
  |  收藏  |  浏览/下载：96/0  |  提交时间：2020/12/28
C(t) dominance of the mixed I/II creep crack: Part II. Extensive creep 期刊论文  OAI收割
THEORETICAL AND APPLIED FRACTURE MECHANICS, 2020, 卷号: 106, 页码: 21
作者:  Dai YW;  Liu YH;  Qin F;  Chao Y;  Qian GA(钱桂安)
  |  收藏  |  浏览/下载：35/0  |  提交时间：2020/05/18
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：59/0  |  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.  
C(t) dominance of the mixed I/II creep crack: Part I. Transient creep 期刊论文  OAI收割
THEORETICAL AND APPLIED FRACTURE MECHANICS, 2019, 卷号: 103, 页码: 18
作者:  Chao YJ;  Qian GA(钱桂安);  Qin F;  Liu YH;  Dai YW
  |  收藏  |  浏览/下载：85/0  |  提交时间：2019/11/26
Stochastic Volterra integral equations with a parameter 期刊论文  OAI收割
Advances in Difference Equations, 2017, 卷号: 2017, 期号: 1
作者:  Wang,Yanqing
  |  收藏  |  浏览/下载：44/0  |  提交时间：2018/07/30
New Procedure to Evaluate Aromaticity at the Density Functional Theory, Hartree-Fock, and Post-Self-Consistent Field Levels 期刊论文  OAI收割
JOURNAL OF COMPUTATIONAL CHEMISTRY, 2011, 卷号: 32, 期号: 2, 页码: 248-259
作者:  Bao, Peng;  Yu, Zhong-Heng
  |  收藏  |  浏览/下载：35/0  |  提交时间：2019/04/09
All-solid-stated laser controller design based on digital optical feedback (EI CONFERENCE) 会议论文  OAI收割
Lasers in Material Processing and Manufacturing II, November 10, 2004 - November 12, 2004, Beijing, China
作者:  Liu L.;  Wang J.-L.;  Wang J.-L.;  Liu L.
收藏  |  浏览/下载：28/0  |  提交时间：2013/03/25
The new design about a CW  digital all-solid-stated LD pumped Nd:YVO 4 controller is introduced. The stable output power of this digital laser controller which adopts Digital Signal Processor(TMS320C31) is approximately 20mW. The whole system is composed of constant- current source  protection circuit  pulse-width modulation circuit  Si-photo-detector and amplified circuit and Digital Signal Processor control system  etc. In terms of error deviation Based on nonlinear control curves of LD power output by Si-photo-detector  the region control can be obtained by means of the PID control algorithm in the software platform  that is  error amendment and high stability laser power output can be achieved. And the precision of temperature control can reduce from 0.2C to 0.04C. By adopted integral separated mode PID control algorithm  the LD output power instability ( %) down to 2%. By way of adopting the new digital design  the work to protect the laser diode  including the continuous adjustable output power with high accuracy and stability  is easily obtained. The internal-external modulation control of the laser power based on digital optical feedback can be accomplished with stable power output. At last  the bringing reasons of noise are analyzed and the solving methods are put forward in this paper.  
Robust integral stabilization of regular linear systems 期刊论文  OAI收割
SCIENCE IN CHINA SERIES F-INFORMATION SCIENCES, 2004, 卷号: 47, 期号: 5, 页码: 545-554
作者:  Xu, CZ;  Feng, DX
  |  收藏  |  浏览/下载：20/0  |  提交时间：2018/07/30