中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories 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25条,第1-10条 帮助

条数/页: 排序方式:
Introducing a special collection of papers in the Journal of High Energy Astrophysics on the Early Results of China's 1st X-ray Astronomy Satellite: Insight-HXMT 期刊论文  OAI收割
Journal of High Energy Astrophysics, 2020, 卷号: 27, 页码: 51-52
作者:  
HXMT
  |  收藏  |  浏览/下载:51/0  |  提交时间:2022/02/08
Astrophysics - High Energy Astrophysical Phenomena  Abstract: Insight-HXMT is the first Chinese X-ray astronomical mission, launched successfully on June 15, 2017, from China's Jiuquan Satellite Launch Center. Insight-HXMT was designed to have a broad energy coverage in X-rays, from 1-250 keV, with excellent timing and adequate energy resolution at soft X-rays, and the largest effective area at hard X-rays. This allows, in particular, to observe bright sources like X-ray binaries (XRBs) in their bright/outburst states with high cadence and high statistics at hard and soft X-rays at once. It was then expected that the Insight-HXMT mission will bring us new insights regarding the characteristics of several source classes. Examples include characterizing High-Mass X-ray Binaries (HMXBs) and the outburst evolution of Low-Mass X-ray Binaries (LMXBs). For instance, in HMXB systems, the region around their Alfven radius that is responsible to determine whether accretion or propeller occurs, or the region around the NS magnetic pole where the intense X-rays are supposed to be produced are specially appealing targets of study. For the LMXBs, the evolution the outburst and the properties of the compact objects themselves are obvious priority targets for Insight-HXMT. Due to the broad coverage in energy, Insight-HXMT is specially well suited to study the influence of thermonuclear (type-I) X-ray bursts upon the surrounding environment.  
Parameter optimization of passive dynamic walking biped with knees (EI CONFERENCE) 会议论文  OAI收割
2012 2nd International Conference on Materials Science and Information Technology, MSIT 2012, August 24, 2012 - August 26, 2012, Xi'an, Shaan, China
作者:  
Zhang P.
收藏  |  浏览/下载:21/0  |  提交时间:2013/03/25
A method to find the optimized parameter values of passive dynamic walking biped is presented. The effects of biped physical parameters on the stability property of passive gaits are studied by simulation experiments. The chosen parameters include the mass distribution  length of leg and slope angle. The stability property of passive walking limit cycles is used as criterion of optimization calculation  including the orbital stability described by eigen-values of linearized Poincare map and the global property described by size of attraction region. The simulation results show how the stability of limit cycle varies when physical parameters of the passive biped change. The work is useful to explore the inherent property of passive dynamic walking and can be used as an important instruction in the mechanical design of biped robots based on principle of passive dynamic walking. (2012) Trans Tech Publications  Switzerland.  
The design of the data communication and display system based on GeoCOM technology (EI CONFERENCE) 会议论文  OAI收割
2012 5th International Symposium on Computational Intelligence and Design, ISCID 2012, October 28, 2012 - October 29, 2012, Hangzhou, China
Geng T.-W.; Wang Z.-Q.; Li D.-N.; Shen C.-W.
收藏  |  浏览/下载:20/0  |  提交时间:2013/03/25
A new triple porosity seepage model in coalbed 会议论文  OAI收割
23rd International Congress of Theoretical and Applied Mechanics, 中国北京/Beijing, China, 2012-08-19
作者:  
Liu YW(刘曰武);  Niu CC(牛丛丛);  Cai Q;  Li HS;  Men XY
收藏  |  浏览/下载:12/0  |  提交时间:2014/04/02
Linear auto disturbance rejection controller for vector-controlled PMSM drive system (EI CONFERENCE) 会议论文  OAI收割
2011 International Conference on Transportation, Mechanical, and Electrical Engineering, TMEE 2011, December 16, 2011 - December 18, 2011, Changchun, China
作者:  
Zhang K.;  Zhang K.;  Zhang K.;  Zhang K.
收藏  |  浏览/下载:35/0  |  提交时间:2013/03/25
A high-performance robust controller of permanent-magnet synchronous motor (PMSM) drive with cascade linear auto disturbance rejection controller (LADRC) is proposed. The robust controller combines the simplicity of linear controller and the merit of the auto disturbance rejection controller (ADRC). First  a systematic mathematical model is derived according to the required specifications for the PMSM drive system. Then  for the model  this paper designs the controller that includes three first-order LADRCs. The controller does not rely on the accurate mathematical model of motor. The controller can estimate and compensate the disturbances that include load disturbance and systematic parameters changes by the linear extended state observer (LESO). Simulation results show that compared with conventional PI controller  the proposed approach has strong robustness. In the same load disturbance  the speed fluctuation of the LADRCs accounts for 30% of PI controller. 2011 IEEE.  
Analysis of measuring errors for the visible light phase-shifting point diffraction interferometer (EI CONFERENCE) 会议论文  OAI收割
2010 OSA-IEEE-COS Advances in Optoelectronics and Micro/Nano-Optics, AOM 2010, December 3, 2010 - December 6, 2010, Guangzhou, China
作者:  
收藏  |  浏览/下载:13/0  |  提交时间:2013/03/25
In order to improve the measuring accuracy of the visible light phase-shifting point diffraction interferometer (PS/PDI) for the extreme ultraviolet lithography (EUVL) aspheric mirrors  the main measuring errors will be discussed in this paper. At first  the elementary configuration and measuring principle of the visible light phase-shifting point diffraction interferometer are introduced briefly  then the different errors which are possible to affect the measuring result are summed up  the errors include PZT phase-shifting error  detector nonlinearity error  detector quantization error  wavelength instability error and intensity instability error of the laser source  vibration error  air refractivity instability error and so on. Through detailed analysis and simulation  the magnitude of these errors can be obtained. By analysing the reasons which cause these errors and the relationship between these errors and interferometer configuration parameters  some methods are put forward to avoid or restrain these errors accordingly.  
Inhibition of electromagnetic interference in control system based on DSP of high-power TEA CO2 laser (EI CONFERENCE) 会议论文  OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
作者:  
Meng F.-J.;  Guo L.-H.;  Wang H.-Q.
收藏  |  浏览/下载:40/0  |  提交时间:2013/03/25
The strong electromagnetic interference (EMI) generated in high-power TEA C02 laser system mainly comes from main discharge circuit  pulse spark switch and power supply. Such strong EMI causes great damage and interference to the control system based on DSP. In this paper  we present the interference sources and their distribution and propose the methods of anti-interference. Measures for hardware design include weakening transient ground potential difference by using equipotential lines between devices  using signal isolation interface to inhibit the transient ground potential interference  and rational layout  shielding and filtering to the control system. And methods for software design include range-limited filter  self-diagnosis and self-repair for the critical data and anti-interference during abnormal reset. The EMI has been inhibited effectively by the anti-interference method proposed above. The result shows that: the software anti-interference method is as important as the hardware anti-interference method for the control system in a complex environment of strong EMI. 2010 IEEE.  
Manufacture of 1.2m reaction bonded silicon carbide mirror blank CFID (EI CONFERENCE) 会议论文  OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes, April 26, 2010 - April 29, 2010, Dalian, China
作者:  
Zhang G.;  Zhang G.;  Zhang G.
收藏  |  浏览/下载:29/0  |  提交时间:2013/03/25
Silicon carbide (SiC) is a new type candidate material for large-scale lightweight space mirror. Its low thermal distortion  high stiffness  fine optical quality and dimensional stability  make SiC an ideal material for large space born telescope. Since ten years Changchun institute optics  fine mechanics and physics (CIOMP) has developed reaction bonded SiC (RB-SiC) technology for space application  and can fabricate RB-SiC mirror with scale less than 1.0 meter for telescope. The green body is prepared with gel-casting method which is an attractive new ceramic forming process for making high-quality  complex-shaped ceramic parts. And then unmolding  drying  binder burning out  reacting bonded  the RB-SiC can be obtained. But with the development of space-born or ground telescope  the scale of primary mirror has exceeded 1.0 meter. So CIOMP has developed an assembly technique which called novel reaction-formed joint technology for larger RB-SiC mirror blank. The steps include joining of green bodies with mixture comprised of SiC particles and phenolic resin etc  firing  machining and sintering. Joining the 1.2 meter RB-SiC mirror blank by the novel reaction-formed joint technology. And testing the welding layer's performance  the results show that the thickness of 54-77m  the microstructure and thermal property can be comparable to the substrate and the mechanical property are excellent in bending strength of 307MPa. 2010 Copyright SPIE - The International Society for Optical Engineering.  
A design of beam shaping unit for 193nm lithography illumination system using angular spectrum theory (EI CONFERENCE) 会议论文  OAI收割
6th International Symposium on Precision Engineering Measurements and Instrumentation, August 8, 2010 - August 11, 2010, Hangzhou, China
作者:  
Zhao Y.;  Zhang W.;  Zhang W.;  Li S.;  Gong Y.
收藏  |  浏览/下载:17/0  |  提交时间:2013/03/25
Off-axis illumination (OAI) technology is widely used to enhance resolution for deep ultraviolet lithography. The realizing methods of OAI include geometrical optics method and physical optics method. However  the former has the disadvantage of weak intensity distribution controlling ability  and the latter introduces simulation errors evidently when dealing with near field diffraction propagation. A diffractive optical element (DOE) designing method using plane wave angular spectrum theory is presented in this paper. Several kinds of OAI modes at near field away from DOE can be realized  and simulation errors and the size of illuminator are also reduced. According to studying the relationships of the sampling point distance of DOE  light beam propagation distance  and the structure of the beam shaping unit  a method of determining the designing parameters is discussed. Using this method  several illumination modes are realized  and simulation results show that all diffraction efficiencies reach up to 84%. The method of DOE manufacturing is analyzed at last  and it is proven to be feasible. 2010 SPIE.  
Ground-based measurement of the space object temperature (EI CONFERENCE) 会议论文  OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes, April 26, 2010 - April 29, 2010, Dalian, China
作者:  
Wu Y.-H.
收藏  |  浏览/下载:68/0  |  提交时间:2013/03/25
Multi-band IR data of the space object can be used in the fields of object identification and space surveillance. The radiation characteristics of the object can be obtained by analyzing these data. These characteristics include temperature  area  emissivity  absorptivity  reflectivity  and temporal trends. The infrared radiation temperature of the space object is an important characteristic from which the object's working state in orbit can be judged. We apply the method of measuring the spectral distribution of the object and fit the data to the Planck formula to determine the temperature. In order to improve the precision of measuring temperature on the space object  we optimize the centric wavelength and the bandwidth effectively. Also  we use a simple program to implement temperature measurement. 2010 Copyright SPIE - The International Society for Optical Engineering.