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Effect of Y_2Ba_4CuNbO_y on the Properties of Single Domain YBCO Superconductor by TSIG Process

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稀有金属材料与工程 2011年第S3期40卷 365-367页

作者： Song Fang, Yang Wanmin, Wang Miao, Li guozheng, Wan feng, Gao Ping, Liang Wei Shaanxi Normal University, Xi’an 710062, China Shaanxi Normal Univ Dept Phys Xian 710062 Peoples R China

The top-seeded infiltration and growth process (TSIG) is an important method to fabricate YBCO bulk superconductors. In this paper, single domain YBCO superconductors with different Gd2Ba4CuWOx (GdW2411) additions have been fabricated by TSIG process, the amount of GdW2411 added to Y2BaCuO5 (Y211) is in the range from 0wt% to 8 wt%, but there is no other additions to the liquid source. The growth morphology, microstructure and levitation force of the YBCO bulks have been investigated, it is found that the levitation force is increasing from 14 to 25 N with the increasing of GdW2411 addition from 0 to 4 wt%, and decreasing from 25 to 7 N with the increasing of GdW2411 addition from 4 to 8 wt%, the largest levitation force is obtained when the GdW2411 content is about 4 wt%. This is helpful for the fabrication of high quality YBCO bulk superconductors.

关键词： infiltration and growth YBCO single-domain Gd2Ba4CuWOx

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溶出液中碳酸钠浓度的控制与分析

轻金属 2000年第8期 10-13页

作者：潘海娥冯国政中国长城铝业公司河南郑州450041

在熟料溶出过程中控制适当的碳酸钠浓度能够有效地控制二次反应的发生 ,改善溶出赤泥的沉降性能 ,有利于Al2 ***2 O溶出率的提高。本文根据实验室及试生产结果 ,阐述了碳酸钠在流程中的作用 ,并提出了较为合适的控制浓度范围。

关键词：碳酸钠浓度控制氧化铝溶出液熟料溶出

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基于上下文模糊C均值聚类的图像分割算法

电子与信息学报 2021年第7期43卷 2079-2086页

作者：徐金东赵甜雨冯国政欧世峰烟台大学计算机与控制工程学院烟台264005 烟台大学光电信息科学与技术学院烟台264005

像素间的上下文相关信息对图像分割算法的抗噪性和准确性具有重要意义,现有的模糊C均值(FCM)聚类算法对此缺乏充分考虑。该文基于对空间上下文的可靠性度量,提出一种模糊C均值聚类算法(RSFCM)应用于图像分割:通过对空间上下文有效建模... 详细信息

像素间的上下文相关信息对图像分割算法的抗噪性和准确性具有重要意义,现有的模糊C均值(FCM)聚类算法对此缺乏充分考虑。该文基于对空间上下文的可靠性度量,提出一种模糊C均值聚类算法(RSFCM)应用于图像分割:通过对空间上下文有效建模来提高聚类算法的抗噪声干扰性能,并研究了一种新的可靠性模糊度量指标,使聚类算法能更好地平衡细节保留和去噪,从而获得更加准确的分割结果。实验选取人工合成图像、交通标志图像和遥感图像3类数据测试聚类算法性能,结果表明,RSFCM在图像分割过程中能有效地抑制椒盐噪声和高斯噪声引起的类内异构及类间同构问题,能提高图像的像素可分性,并有效地保留了图像的边缘细节。

关键词：图像分割聚类模糊C均值空间上下文

Solving the input data in error correc-tion of optical fabrication by finite Fourier coefficient algorithm

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Science China(Technological Sciences) 2006年第1期49卷 50-60页

作者： CHENG Haobo1,2, SUN guozheng3 & feng Zhijing2 1. Department of Optical Engineering, Beijing Institute of Technology, Beijing 100081, China 2. Department of Precision Instruments and Mechanology, Tsinghua University, Beijing 100084, China 3. China North Industries Group Corporation, Beijing 100089, China Department of Optical Engineering Beijing Institute of Technology Beijing China Department of Precision Instruments and Mechanology Tsinghua University Beijing China China North Industries Group Corporation Beijing China

A free-form lens (FFL) is a special surface that is difficult to be fabricated. FFL are usually fabricated by computer-controlled optical surfacing (CCOS) technique. During CCOS, the material removal amount is determined by the unit removal function (URF) convoluting with the input data――the dwell time. When the removal amount and the URF are known, how to solve the input data involves the special algorithm――deconvolution. Usually, the input data are solved by virtue of low pass filter or iterative methods. However, an approximation solution would destroy the machining stability nec-essary to perform precisely CCOS. In this paper, to solve the input data, a new method that is based on the finite Fourier coefficient is put forward. It can give a continuous and accurate solution for fabricating choice. Several parameters are simulated, which influ-ence the process of CCOS, and evaluating on the effect of the method is also carried out. Experimental results verify that this method is suitable for guiding the manufacturing of high precision FFL.

关键词： optical fabrication, computer controlled optical surfacing, free-form lens, finite Fourier coefficient, error correction.

基于ESI的教育部直属师范大学学科竞争力计量分析

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情报探索 2017年第8期 50-56页

作者：丰国政华南师范大学图书馆广东广州510631

[目的/意义]分析教育部直属师范大学ESI学科竞争力,为促进高校"双一流"建设提供参考。[方法/过程]以北京师范大学、华东师范大学等6所教育部直属师范大学为研究对象,选取ESI学科排名、论文数、被引频次、热点论文等指标构建高校学科竞... 详细信息

[目的/意义]分析教育部直属师范大学ESI学科竞争力,为促进高校"双一流"建设提供参考。[方法/过程]以北京师范大学、华东师范大学等6所教育部直属师范大学为研究对象,选取ESI学科排名、论文数、被引频次、热点论文等指标构建高校学科竞争力评价体系,计量分析各师范大学的学科竞争力。[结果/结论]教育部直属师范大学ESI学科竞争力呈稳步提升态势,但与世界一流大学相比还存在较大差距,ESI学科生产力总体偏低、影响力相对薄弱、发展力有待提升、创新力亟需加强。各师范大学要结合实际,优化学科结构,挖掘潜力,提高论文数量和质量,加强国际学术交流,提升学科影响力。

关键词：学科竞争力科学指标计量分析师范大学