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7条，第1-7条 帮助

条数/页： 排序方式：
Extracting Cycle-aware Feature Curve Networks from 3D Models 期刊论文  OAI收割
COMPUTER-AIDED DESIGN, 2021, 卷号: 131, 页码: 11
作者:  Lu, Zhengda;  Guo, Jianwei;  Xiao, Jun;  Wang, Ying;  Zhang, Xiaopeng
  |  收藏  |  浏览/下载：16/0  |  提交时间：2021/03/08
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：58/0  |  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.  
Feature-Related Searching Control Model for Curve Detection 期刊论文  OAI收割
IEEE Transactions on Cybernetics, 2019, 卷号: 49, 期号: 2, 页码: 580-591
作者:  Zhang MY(张茗奕);  Xilong Liu;  De Xu;  Zhiqiang Cao
  |  收藏  |  浏览/下载：52/0  |  提交时间：2019/05/08
Modeling 3D human body with a smart vest 期刊论文  OAI收割
COMPUTERS & GRAPHICS-UK, 2018, 卷号: 75, 页码: 44-58
作者:  Xu, Haocan;  Li, Jituo;  Lu, Guodong;  Deng, Haijin;  Zhang, Dongliang
  |  收藏  |  浏览/下载：40/0  |  提交时间：2019/12/16
Optimal sensors deployment for tracking level curve based on posterior Cramer-Rao lower bound in scalar field 会议论文  OAI收割
The 7th International Conference on Intelligent Robotics and Application (ICIRA2014), Guangzhou, China, December 17-20, 2014.
作者:  Zhao WT(赵文涛);  Yu JC(俞建成);  Zhang AQ(张艾群);  Li Y(李岩)
收藏  |  浏览/下载：55/0  |  提交时间：2014/12/29
Space optics remote sensor focusing components mechanics characteristic analysis based on FEM (EI CONFERENCE) 会议论文  OAI收割
International Symposium on Photoelectronic Detection and Imaging 2009: Material and Device Technology for Sensors, June 17, 2009 - June 19, 2009, Beijing, China
作者:  Wang B.;  Ren J.-Y.;  Wang B.
收藏  |  浏览/下载：147/0  |  提交时间：2013/03/25
Space optical remote sensor is very important in many fields of science and military significance. It is widely applied. Space optical remote sensor design and manufacturing require precision and stability. Focusing mechanics is an important component of remote sensors. Focusing mechanics can guarantee the stability of the entire mechanics focusing accuracy  therefore the stability of research focusing mechanics is very important. In order to guarantee the space optics remote sensor focusing mechanics the stability  takes steps the space optics remote sensor focusing organization mechanics characteristic analysis from the classics contact theory. This article uses international general non-linear finite element analysis software ABAQUS to carry on mechanics characteristic analysis to the space optics remote sensor focusing mechanics. First acts according to the focusing mechanics unique feature  carries on the finite element to the structural model the grid division  the material attribute disposition and the boundary condition indeed grades. Then establishment contact non-linear finite element model  and to focusing organization finite element model infliction unit action. Like this contacts the result and the equivalent static analysis result which the nonlinear analysis obtains carries on the contrast and the analysis. This article last count result modality is 90HZ  satisfies the space optics remote sensor structure overall modality to request to be bigger than 50HZ.This article when carries on the dynamic analysis  extracts the structure kinetic energy and the acceleration curve. In the dynamic analysis obtained transient response analysis modality 70.5Hz  this also is bigger than 50HZ. The dynamic analysis indicated the structure dynamic stability has the distinct enhancement  has provided certain foundation for the space optics remote sensor following development work  reduced the overall system development cycle. 2009 SPIE.  
图像特征检测与匹配研究 学位论文  OAI收割
工学博士, 中国科学院自动化研究所: 中国科学院研究生院, 2008
作者:  王志衡
收藏  |  浏览/下载：79/0  |  提交时间：2015/09/02