期刊文献+
共找到7篇文章
< 1 >
每页显示 20 50 100
Research of Dynamic Material Handling in an Automobile General Assembly Line Based on Real-time Information
1
作者 WANG Nan LI Shi-qi WANG Jun-feng ZHANG Zhen-li 《International Journal of Plant Engineering and Management》 2012年第1期34-43,共10页
The status of material delivery of an automobile general assembly line is analyzed, and the technique to achieve the real-time tracking of assembly status information is proposed based on RFID( Radio Frequency Identi... The status of material delivery of an automobile general assembly line is analyzed, and the technique to achieve the real-time tracking of assembly status information is proposed based on RFID( Radio Frequency Identification). Thus the consumption of line-side buffer is obtained dynamically, then the type and quantity of needed material are fed back to the subsystem of material handling; the algorithm for determining the best time departure time of delivery driver based on minimizing of total time penalty function is proposed. This approach makes the material amount of a single delivery trip maximized and improves the efficiency of delivery drivers significantly in the case of does not affect the assembly line normal throughput. Additionally, although this dynamic material handling method is developed for the automobile assembly plant, it should be pointed out that this method is also applicable to other mixed model assembly plants such as electronics, semiconductor and aerospace industry. 展开更多
关键词 automobile general assembly line material handling best departure time
下载PDF
External calibrator in global signal experiment for detection of the epoch of reionization
2
作者 Yan Huang Xiang-Ping Wu +5 位作者 Quan Guo Qian Zheng Bi-Ying Li Huan-Yuan Shan Ke-Jia Lee Hai-Guang Xu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2021年第10期17-26,共10页
We present a conceptual design study of external calibrators in the 21 cm experiment towards detecting the globally averaged radiation of the epoch of reionization(EoR).Employment of external calibrator instead of int... We present a conceptual design study of external calibrators in the 21 cm experiment towards detecting the globally averaged radiation of the epoch of reionization(EoR).Employment of external calibrator instead of internal calibrator commonly used in current EoR experiments allows removing instrumental effects such as beam pattern,receiver gain and instability of the system if the conventional three-position switch measurements are implemented in a short time interval.Furthermore,in the new design the antenna system is placed in an underground anechoic chamber with an open/closing ceiling to maximally reduce the environmental effect such as RFI and ground radiation/reflection.It appears that three of the four external calibrators proposed in this paper,including two indoor artificial transmitters and one outdoor celestial radiation(the Galactic polarization),fail to meet our purpose.Diurnal motion of the Galactic diffuse emission turns out to be the most probable source as an external calibrator,for which we have discussed the observational strategy and the algorithm of extracting the EoR signal. 展开更多
关键词 cosmology:observations dark ages REIONIZATION radio lines:general methods:observational
下载PDF
A small electron beam ion trap/source facility for electron/neutral-ion collisional spectroscopy in astrophysical plasmas
3
作者 Gui-Yun Liang Hui-Gang Wei +8 位作者 Da-Wei Yuan Fei-Lu Wang Ji-Min Peng Jia-Yong Zhong Xiao-Long Zhu Mike Schmidt Günter Zschornack Xin-Wen Ma Gang Zhao 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2018年第1期1-10,共10页
Spectra are fundamental observation data used for astronomical research,but understanding them strongly depends on theoretical models with many fundamental parameters from theoretical calculations.Different models giv... Spectra are fundamental observation data used for astronomical research,but understanding them strongly depends on theoretical models with many fundamental parameters from theoretical calculations.Different models give different insights for understanding a specific object.Hence,laboratory benchmarks for these theoretical models become necessary.An electron beam ion trap is an ideal facility for spectroscopic benchmarks due to its similar conditions of electron density and temperature compared to astrophysical plasmas in stellar coronae,supernova remnants and so on.In this paper,we will describe the performance of a small electron beam ion trap/source facility installed at National Astronomical Observatories,Chinese Academy of Sciences.We present some preliminary experimental results on X-ray emission,ion production,the ionization process of trapped ions as well as the effects of charge exchange on the ionization. 展开更多
关键词 X-ray:general atomic processes line:formation method:laboratory:atomic
下载PDF
The LAMOST survey of background quasars in the vicinity of M31 and M33–Ⅲ.results from the 2013 regular survey
4
作者 Zhi-Ying Huo Xiao-Wei Liu +7 位作者 Mao-Sheng Xiang Jian-Rong Shi Hai-Bo Yuan Yang Huang Yong Zhang Yong-Hui Hou Yue-Fei Wang Ming Yang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2015年第8期1438-1448,共11页
In this work, we report new quasars discovered in fields in the vicinity of the Andromeda(M31) and Triangulum(M33) galaxies with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST, also called t... In this work, we report new quasars discovered in fields in the vicinity of the Andromeda(M31) and Triangulum(M33) galaxies with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST, also called the Guo Shou Jing Telescope) during the 2013 observational season, the second year of the regular survey. In total, 1330 new quasars are discovered in an area of ~133 deg2 around M31and M33. With i magnitudes ranging from 14.79 to 20.0 and redshifts from 0.08 to4.85, the 1330 new quasars represent a significant increase in the number of identified quasars in fields in the vicinity of M31 and M33. Up to now, there have been a total of 1870 quasars discovered by LAMOST in this area. The much enlarged sample of known quasars in this area can potentially be utilized to construct a precise astrometric reference frame for the measurement of minute proper motions of M31, M33 and their associated substructures, which are vital for understanding the formation and evolution of M31, M33 and the Local Group of galaxies. Moreover, in the sample,there are a total of 45, 98 and 225 quasars with i magnitudes brighter than 17.0, 17.5and 18.0 respectively. In the aforementioned brightness bins, 15, 35 and 84 quasars are reported here for the first time, and 6, 21 and 81 are reported in our pervious work. In addition, 0, 1 and 6 are from the Sloan Digital Sky Survey and 24, 41 and 54 are from the NED database. These bright quasars provide an invaluable sample to study the kinematics and chemistry of the interstellar/intergalactic medium of the Local Group. 展开更多
关键词 galaxies: individual(M31 M33)—quasars: general—quasars: emission lines
下载PDF
AN SQP ALGORITHM WITH NONMONOTONE LINE SEARCHFOR GENERAL NONLINEAR CONSTRAINED OPTIMIZATION PROBLEM 被引量:3
5
作者 He, GP Diao, BQ Gao, ZY 《Journal of Computational Mathematics》 SCIE CSCD 1997年第2期179-192,共14页
In this paper, an SQP type algorithm with a new nonmonotone line search technique for general constrained optimization problems is presented. The new algorithm does not have to solve the second order correction subpro... In this paper, an SQP type algorithm with a new nonmonotone line search technique for general constrained optimization problems is presented. The new algorithm does not have to solve the second order correction subproblems for each iterations, but still can circumvent the so-called Maratos effect. The algorithm's global convergence and superlinear convergent rate have been proved. In addition, we can prove that, after a few iterations, correction subproblems need not be solved, so computation amount of the algorithm will be decreased much more. Numerical experiments show that the new algorithm is effective. 展开更多
关键词 SQP SI AN SQP ALGORITHM WITH NONMONOTONE line SEARCHFOR general NONlineAR CONSTRAinED OPTIMIZATION PROBLEM MATH line
原文传递
An Analysis of Average Pulsar Profiles and A Study of the ρ-P relation of Pulsars 被引量:1
6
作者 Hua-XiangWang Xin-JiWu 《Chinese Journal of Astronomy and Astrophysics》 CSCD 北大核心 2003年第5期469-477,共9页
Using the method of Gaussian Fit Separation of Average Profile (GF-SAP), we re-examine the average profiles of nine pulsars at several frequencies, ranging from 408-1642 MHz. This method enables us to obtain the numbe... Using the method of Gaussian Fit Separation of Average Profile (GF-SAP), we re-examine the average profiles of nine pulsars at several frequencies, ranging from 408-1642 MHz. This method enables us to obtain the number of components for each pulsar, and the parameters for each component, the width, position and amplitude. The ρ-P relation for the inner cone and outer cone are studied separately, and the results are, respectively, ρ = p-0.51±0.05 and ρ= p-0.42±0.06 The results can be interpreted as a confirmation of the double-cone structure of pulsar emission beams. The altitudes of emission region, and the radius-to-frequency-map (RFM) are also examined; for the outer cone, we obtained γ(v) ∝v-0.19±0.09. 展开更多
关键词 stars: pulsar: general - line: profiles
下载PDF
Discovery of six high-redshift quasars with the Lijiang 2.4 m telescope and the Multiple Mirror Telescope 被引量:1
7
作者 Xue-Bing Wu Wen-Wen Zuo +6 位作者 Qian Yang Wei-Min Yi Chen-Wei Yang Wen-Juan Liu Peng Jiang Xin-Wen Shu Hong-Yan Zhou 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2012年第9期1185-1190,共6页
Quasars with redshifts greater than 4 are rare, and can be used to probe the structure and evolution of the early universe. Here we report the discovery of six new quasars with i-band magnitudes brighter than 19.5 and... Quasars with redshifts greater than 4 are rare, and can be used to probe the structure and evolution of the early universe. Here we report the discovery of six new quasars with i-band magnitudes brighter than 19.5 and redshifts between 2.4 and 4.6 from spectroscopy with the Yunnan Faint Object Spectrograph and Camera (YFOSC) at the Lijiang 2.4 m telescope in February, 2012. These quasars are in the list of z > 3.6 quasar candidates selected by using our proposed J K/i Y criterion and the photometric redshift estimations from the SDSS optical and UKIDSS near-IR photometric data. Nine candidates were observed by YFOSC, and five among six new quasars were identified as z > 3.6 quasars. One of the other three objects was identified as a star and the other two were unidentified due to the lower signal-to-noise ratio of their spectra. This is the first time that z > 4 quasars have been discovered using a telescope in China. Thanks to the Chinese Telescope Access Program (TAP), the redshift of 4.6 for one of these quasars was confirmed by the Multiple Mirror Telescope (MMT) Red Channel spectroscopy. The continuum and emission line properties of these six quasars, as well as their central black hole masses and Eddington ratios, were obtained. 展开更多
关键词 quasars: general quasars: emission lines galaxies: active galax- ies: high-redshift
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部