中国科学院机构知识库网格系统: 检索

Superplastic behavior of a Ni-Co-base superalloy with high gamma '-phase content 期刊论文 OAI收割
MATERIALS LETTERS, 2023, 卷号: 348, 页码: 4
作者: Al-Hammadi, Rashad A.; Zhang, Rui; Cui, Chuanyong; Zhou, Zijian; Zhou, Yizhou

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收藏 | 浏览/下载：10/0 | 提交时间：2024/01/08

Superplasticity Metal and alloys Difficult-to-deform superalloy Microstructure gamma '-phase

No pulsed radio emission during a bursting phase of a Galactic magnetar 期刊论文 OAI收割
Nature, 2020, 卷号: 587, 页码: 63-65
作者: HXMT

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收藏 | 浏览/下载：44/0 | 提交时间：2022/02/08

Astrophysics - High Energy Astrophysical Phenomena Abstract: Fast radio bursts (FRBs) are millisecond-duration radio transients of unknown physical origin observed at extragalactic distances^1-3. It has long been speculated that magnetars are the engine powering repeating bursts from FRB sources^4-13, but no convincing evidence has been collected so far¹⁴. Recently, the Galactic magnetar SRG 1935+2154 entered an active phase by emitting intense soft íray bursts¹⁵. One FRB-like event with two peaks (FRB 200428) and a luminosity slightly lower than the faintest extragalactic FRBs was detected from the source, in association with a soft íray/hard-X-ray flare^18-21. Here we report an eight-hour targeted radio observational campaign comprising four sessions and assisted by multi-wavelength (optical and hard-X-ray) data. During the third session, 29 soft-íray repeater (SGR) bursts were detected in íray energies. Throughout the observing period, we detected no single dispersed pulsed emission coincident with the arrivals of SGR bursts, but unfortunately we were not observing when the FRB was detected. The non-detection places a fluence upper limit that is eight orders of magnitude lower than the fluence of FRB 200428. Our results suggest that FRB-SGR burst associations are rare. FRBs may be highly relativistic and geometrically beamed, or FRB-like events associated with SGR bursts may have narrow spectra and characteristic frequencies outside the observed band. It is also possible that the physical conditions required to achieve coherent radiation in SGR bursts are difficult to satisfy, and that only under extreme conditions could an FRB be associated with an SGR burst.

Granites: Leading study issue for continental evolution 期刊论文 OAI收割
ACTA PETROLOGICA SINICA, 2017, 卷号: 33, 期号: 5, 页码: 1369-1380
作者: Zhai MingGuo

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收藏 | 浏览/下载：24/0 | 提交时间：2017/11/16

Granite Continental evolution Question and difficult points New issues

Design of the real-time autofocusing system for collimator with long focus length and large aperture (EI CONFERENCE) 会议论文 OAI收割
2011 International Academic Conference on Numbers, Intelligence, Manufacturing Technology and Machinery Automation, MAMT 2011, December 24, 2011 - December 25, 2011, Wuhan, China
作者: Zhang X.; Zhang X.; Zhang X.

收藏 | 浏览/下载：42/0 | 提交时间：2013/03/25

Large aperture collimator which has been widely used for calibrating and testing various optical devices plays an essential role in correlative laboratories. As being the basic testing and calibration equipment the large aperture collimator's accuracy should be much higher than the device under testing in order to ensure the accuracy of the measurement. However the process of adjusting the collimator is extremely complicated due to the collimator's large aperture and long focal length. So it is difficult to ensure the measurement's quality and easy to cause the system being vulnerable to the surrounding environment. One of the most common problems is defocus. In order to solve the problem above this issue presents a new type of autocollimator autofocusing system which uses pentaprism instead of using large-aperture plane mirror semiconductor lasers as light source and CCD sensor as receiver. The system is smaller lighter and more convenient when using. The computer simulation shows that the autofocusing system's resolution could reach the accuracy of 40m. If we use the relevant algorithms to execute the sub-pixel scanning the resolution could reach the accuracy of 10m. It shows that the system could satisfy the required testing precision of testing large aperture optical device.

A new low-bandwidth and wireless transmission scheme for CCd image (EI CONFERENCE) 会议论文 OAI收割
2012 International Symposium on Photonics and Optoelectronics, SOPO 2012, May 21, 2012 - May 23, 2012, Shanghai, China
作者: Zhang Y.

收藏 | 浏览/下载：35/0 | 提交时间：2013/03/25

The CCD (Charge-coupled Device) image sensor with its high resolution is capable of providing high definition image. However transmission requires high bandwidth which makes it very difficult to process and transmit in a long distance. The purpose of this paper is to propose a new method to process and transmit CCD image which can guarantee a low-bandwidth and long-distance data transmission. The innovation is that the transmission content of CCD image data can be flexibly selected and compressed firstly which will reduce the transmission data. Then it is processed on the base of communication protocol so that it can be fit for wireless transmission. At last it is transformed into wireless signal and transmitted using 3G technology. As a result the paper presents a wireless transmission scheme with the rate of 1.5Mbps for CCD image. 2012 IEEE.

SPH simulation of free surface flows with moving objects 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:

收藏 | 浏览/下载：12/0 | 提交时间：2014/04/02

moving simulation surface rotation features simulating cylinder solid violent naturally treat model simulated difficult fluid involve inherent method obtained entry

A hybrid median filter for enhancing dim small point targets and its fast implementation (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Multimedia and Signal Processing, CMSP 2011, May 14, 2011 - May 15, 2011, Guilin, Guangxi, China
Yang Q.

收藏 | 浏览/下载：22/0 | 提交时间：2013/03/25

Weak stars and middle altitude orbit satellites or high altitude orbit satellites are presented as dim point targets in images of astronomical observation. They have low intensity and occupy few pixels in image. In most situations the background of sky is always ununiform and there exists pulse noises. Thus results in targets submerging in background noises and low signal noise ratio (SNR). Median filter is an effective method for removing pulse noise. But it can blur image after modifying gray of non-noise pixels when image has low SNR. A hybrid median filter algorithm is proposed to process low SNR dim point targets image. The newly proposed method can suppress the pulse noises also can increase target $SNR$ and does not add extra fake targets. The time complexity of median filter is O(N2)(N is the widow size) and is difficult to implement in hardware. For quasi real time application a fast implementation of our hybrid median filter is proposed to reduce the time complexity to O(N). Experimental results show that the newly proposed algorithm is superior to ordinary median filter and fast median filter by comparing visual effect and performance. 2011 IEEE.

Design and analysis of auto-focus assembly for spaceborne remote sensing camera (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electronics, Communications and Control, ICECC 2011, September 9, 2011 - September 11, 2011, Ningbo, China
作者: Chen W.; Gao X.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

Spaceborne remote sensing camera may be out of focus when the environment and photographic distance changes. In order to get higher ground sampled distance for the camera based on the experience gained from the development of a remote sensing camera working principle of auto-focus assembly control system was discussed. Time of waveform extraction was reduced. It sets force an auto-focus assembly that uses cam and line guide rail in order to move the lens group. The motion error of the auto-focus assembly was difficult to be eliminated and would affect on the focusing accuracy of the spaceborne remote sensing camera directly. So it was analyzed at both ends of the focusing structure. The CCD detector can keep stable when the remote sensing camera is imaging. The motion error was tested to verify the validity of the simulation result and it is less than 0.01mm. Its accuracy meets using demand. The focusing method of moving focal plane is suitable for spaceborne remote sensing camera. 2011 IEEE.

Application of quantitative fault tree analysis based on fuzzy synthetic evaluation to software development for space camera (EI CONFERENCE) 会议论文 OAI收割
2011 2nd International Conference on Artificial Intelligence, Management Science and Electronic Commerce, AIMSEC 2011, August 8, 2011 - August 10, 2011, Zhengzhou, China
作者: Li Y.; Li Y.; Li Y.; Li Y.

收藏 | 浏览/下载：29/0 | 提交时间：2013/03/25

Software reliability analysis is a significant measure to guide design of software reliability. Now software fault tree method to carry on software reliability analysis is used more and more. But it can only qualitative carry on the analysis because of many reasons. For example the scale of software is enlarging the software architecture is getting more and more complex the reason of software fault is very difficult to analyze the software is difference with hardware and it is very hard to obtain the expiration the quantitative data and so on. The space camera is extremely high to the reliable request. So the qualitative analysis is unable to satisfy the analysis request. In view of space camera characteristics a method of fault tree analysis based on fuzzy synthetic evaluation is proposed. The results show that the new method makes software quantitative fault tree analysis possible and optimizes. It can also solve the problem of software component which is unable to quantize precisely. 2011 IEEE.

Realization of the imaging-auto-focus on the APRC using splicing- CCD (EI CONFERENCE) 会议论文 OAI收割
International Conference on Graphic and Image Processing, ICGIP 2011, October 1, 2011 - October 2, 2011, Cairo, Egypt
Lu Z.; Guo Y.; Xue X.; Ma T.; Lv H.

收藏 | 浏览/下载：14/0 | 提交时间：2013/03/25

It is difficult to deal with the auto-focus of aerial push-broom remote sensing camera (APRC) based on image processing. First of all this paper recommended the Splicing structure of CCD in the APRC Based on this auto-focus method which is made use of the overlapping area of CCD mosaic structure was proposed combined with the characteristic of the imaging mode. After analyzing of experiments about all kinds of focus-examine functions based on image processing the gradient square function has been chosen. The experimental results show that the proposed auto-focus method for the APRC is proved to be feasible and real-time. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).