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Zn∶In∶Fe∶LiNbO_3晶体的生长及其二波耦合效应的研究
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作者 徐悟生 石绍君 朱质彬 《人工晶体学报》 EI CAS CSCD 北大核心 2000年第S1期60-,共1页
ZnO(4mol%),In 2O 3(1mol%)and Fe 2O 3(0.05mol%)were doped in LiNbO 3 and Czochralski method was used to grow Zn∶In∶Fe∶LiNbO 3 crystal.The diameter of the crystal we grew is 30mm.The technology parameter we took is t... ZnO(4mol%),In 2O 3(1mol%)and Fe 2O 3(0.05mol%)were doped in LiNbO 3 and Czochralski method was used to grow Zn∶In∶Fe∶LiNbO 3 crystal.The diameter of the crystal we grew is 30mm.The technology parameter we took is that the axial temperature gradient is 40℃/cm,the growth rate is 1mm/h, the rotation rate is 15-25r/min,the temperature of polarization is 1220℃ and the current density of polarization is 5mA/cm 2.The wafer dimension is 10mm×10mm×3mm and was covered in Li 2CO 3 powder to reduce.The reduction temperature is 500℃ and reduction time is 30 hours. OH - stretch vibration transmission spectra were measured by Fourier infrared spectrophotometer. There are two absorption peaks in OH - spectra of Zn∶In∶Fe∶LiNbO 3,in which one is at 3534cm -1 (2.83μm) and the other is at 3505cm -1 (2.85μm).The peak at 2.85μm is far lower than that at 2.83μm. Because of the threshold effect of Zn 2+ and In 3+ ,the peak at 2.83μm is generated and the peak at 2.85μm is related with Fe 3+ .In LiNbO 3 only doped with Fe,Li + site is taken place by Fe 3+ .When doping Zn 2+ and In 3+ in high concentration,these two ions take place Nb that is at Li site and Fe 3+ substitutes for Nb 5+ at the same time.The interaction between Fe 3+ and OH - make the OH - peak shift to 2.85μm. 展开更多
关键词 Zn∶ln∶Fe∶LiNbO 3 crystal photorefractive effect response time crystal pulling
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Study on Method of Comprehensive Evaluating for Information System Projects 被引量:2
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作者 Xu, Weixiang Zhang, Quanshou 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2000年第2期17-24,共8页
In this paper, a new method of evaluation for information system project is proposed on the basis of the meta-synthesis methodology from qualitative analysis to quantitative analysis. DHGF is an integrated method of i... In this paper, a new method of evaluation for information system project is proposed on the basis of the meta-synthesis methodology from qualitative analysis to quantitative analysis. DHGF is an integrated method of improved Delphi, analytic hierarchy process, grey interconnect degree and fuzzy comprehensive evaluating. It gives full play to their advantages and controls theirs disadvantages. The feasibility and effectiveness of DHGF are shown in the practical example. 展开更多
关键词 Computer systems programming Fuzzy sets Mathematical models response time (computer systems)
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Analysis and Study of Parallel Processing Mode inVLDB Decision Support System
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作者 Zhang, Liming Feng, Qiujie 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2000年第2期66-72,共7页
Nowadays, many kinds of computer network data management systems have been built widely in China. People have realized widely that management information system (MIS) has brought a revolution to the management mechani... Nowadays, many kinds of computer network data management systems have been built widely in China. People have realized widely that management information system (MIS) has brought a revolution to the management mechanism. Moreover, the managers of company need wide-range and comprehensive decision information more and more urgently which is the character of information explosion era. The needs of users become harsher and harsher in the design of MIS, and these needs have brought new problems to the general designers of MIS. Furthermore, the current method of traditional database development can't solve so big and complex problems of wide-range and comprehensive information processing. This paper proposes the adoption of parallel processing mode, the built of new decision support system (DSS) is to discuss and analyze the problems of information collection, processing and the acquirement of full-merit information with cross-domain and cross-VLDB (very-large database). 展开更多
关键词 Computer systems programming Data acquisition Data reduction Database systems Decision support systems response time (computer systems)
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