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储纬器定长方法的研究 被引量:1
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作者 徐山青 施亚贤 《棉纺织技术》 CAS CSCD 北大核心 2003年第2期20-22,共3页
分析了IWF 84 0 7型和ROJ Elf型两种储纬器的定长方法 ,比较了各自的优缺点 ,提出在不改变储纱鼓直径条件下提高引纬定长精度的三种方法 :增加电磁针数量、废边纱右侧增设探纬器、测量纬纱引入速度。
关键词 IWF8407型 ROJ-Elf型 储纬器 定长方法 测量 精度
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储纬器定长方法的探讨 被引量:2
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作者 徐山青 《南通工学院学报(自然科学版)》 2002年第3期7-9,共3页
文章分析了IWF8407和ROJ—Elf两种储纬器的定长方法 ,提出了在不改变储纬鼓直径条件下提高引纬定长精度的三种方法 ,可供开发设计新型储纬器时参考。
关键词 定长方法 无梭织机 储纬器 储纬鼓 定长精度 纬纱消耗 纺织
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按c-分层不定长CAT的研究 被引量:11
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作者 王茜娟 丁树良 谭渊 《江西师范大学学报(自然科学版)》 CAS 北大核心 2005年第3期227-230,238,共5页
有文献研究按c-分层定长CAT,该文研究按c-分层不定长CAT.通过实验对比,得出按c-分层不定长CAT具有以下优越性:(1)能有效控制题目曝光度,考试具有较高的安全性;(2)考生测试项目的内容覆盖符合预设的内容域比例;(3)不定长方法比定长的方... 有文献研究按c-分层定长CAT,该文研究按c-分层不定长CAT.通过实验对比,得出按c-分层不定长CAT具有以下优越性:(1)能有效控制题目曝光度,考试具有较高的安全性;(2)考生测试项目的内容覆盖符合预设的内容域比例;(3)不定长方法比定长的方法具有更高的效率.另外,我们给出了一个综合评价指标. 展开更多
关键词 CAT 分层 综合评价指标 文献研究 实验对比 有效控制 测试项目 定长方法 曝光度 安全性
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相对体积损耗比对微细电火花加工的影响及其测量方法 被引量:1
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作者 许加利 李建功 +1 位作者 裴景玉 胡德金 《上海交通大学学报》 EI CAS CSCD 北大核心 2009年第9期1508-1511,共4页
利用定长补偿方法的仿真模型分析了相对体积损耗比(ν)的误差对微细电火花加工结果的影响,在仿真分析的基础上推导出实际相对体积损耗比(ν*)的计算公式,通过单槽微细电火花定长补偿加工实验,验证了ν*计算公式的正确性,并得到加工后底... 利用定长补偿方法的仿真模型分析了相对体积损耗比(ν)的误差对微细电火花加工结果的影响,在仿真分析的基础上推导出实际相对体积损耗比(ν*)的计算公式,通过单槽微细电火花定长补偿加工实验,验证了ν*计算公式的正确性,并得到加工后底面轮廓及其稳定深度.结果表明:当补偿所采用的ν>ν*或ν<ν*时,定长补偿加工中会出现过切或欠切现象,经过一段加工距离后,均出现了稳定的锯齿状加工轮廓,且稳定部分的深度仅与ν*值的大小有关,而与初始分层厚度误差无关;所推导出的ν*计算公式结合了预加工结果,可以得到精确的ν值;其底面轮廓与仿真结果的变化趋势一致,计算所得ν值与通过精确测量所得实际值吻合. 展开更多
关键词 微细电火花 定长补偿方法 相对体积损耗比
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改进的谱分析法定量估算T波电交替的研究 被引量:8
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作者 余辉 李恒达 +1 位作者 张力新 杜非 《中国生物医学工程学报》 CAS CSCD 北大核心 2011年第2期213-219,共7页
T波交替现象已成为医生用于评估心脏病人的指标之一。但TWA检测中的定量问题尚未解决。本研究在传统谱分析方法的基础上进行了改进,采用定长积分平均的方式替代原有的单参照点模式,数据结果表明改进后算法的时域抗干扰能力有了显著的提... T波交替现象已成为医生用于评估心脏病人的指标之一。但TWA检测中的定量问题尚未解决。本研究在传统谱分析方法的基础上进行了改进,采用定长积分平均的方式替代原有的单参照点模式,数据结果表明改进后算法的时域抗干扰能力有了显著的提高。采用线性模型人工合成TWA信号进行仿真研究,针对非理想状态下的TWA信号,基于实际情况中生理信号的多变性和不均匀性,修正了David S.Rosenbaum等人的估算式,提出了一种新的TWA定量分析方法,测试结果表明在信噪比大于10 dB时,估算的TWA幅值的绝对误差控制在±5μV以内。 展开更多
关键词 心电图 T波交替 改进的谱分析法 人工合成模拟心电信号 定长积分平均方法
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Accurate quantification of astaxanthin from Haematococcus crude extract spectrophotometrically 被引量:4
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作者 李夜光 苗凤萍 +3 位作者 耿亚洪 卢大炎 张成武 曾明涛 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第4期627-637,共11页
The influence of alkali on astaxanthin and the optimal working wave length for measurement of astaxanthin from Haematocoecus crude extract were investigated, and a spectrophotometric method for precise quantification ... The influence of alkali on astaxanthin and the optimal working wave length for measurement of astaxanthin from Haematocoecus crude extract were investigated, and a spectrophotometric method for precise quantification of the astaxanthin based on the method of Boussiba et al. was established. According to Boussiba's method, alkali treatment destroys chlorophyll. However, we found that: 1) carotenoid content declined for about 25% in Haematococcus fresh cysts and up to 30% in dry powder of Haematococcus broken cysts after alkali treatment; and 2) dimethyl sulfoxide (DMSO)-extracted chlorophyll of green Haematococeus bares little absorption at 520-550 nm. Interestingly, a good linear relationship existed between absorbance at 530 nm and astaxanthin content, while an unknown interference at 540-550 nm was detected in our study. Therefore, with 530 nm as working wavelength, the alkali treatment to destroy chlorophyll was not necessary and the influence of chlorophyll, other carotenoids, and the unknown interference could be avoided. The astaxanthin contents of two samples were measured at 492 nm and 530 nm; the measured values at 530 nm were 2.617 g/100 g and 1.811 g/100 g. When compared with the measured values at 492 nm, the measured values at 530 nm decreased by 6.93% and 11.96%, respectively. The measured values at 530 nm are closer to the true astaxanthin contents in the samples. The data show that 530 nm is the most suitable wave length for spectrophotometric determination to the astaxanthin in Haematococcus crude extract. 展开更多
关键词 Haematococcus pluvialis astaxanthin quantification SPECTROPHOTOMETRY
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Long Distance GIL PD Fault Localization Method Based on Amplitude Difference and Time Difference Calculation of UHF Coupling Signal
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作者 Zhang Hui Hu Po Tao Ke 《Journal of Mechanics Engineering and Automation》 2016年第1期39-46,共8页
In the long distance GIL under certain conditions, this paper researches and realizes detection of PD characters and accurate fault localization through UHF coupling sensors at different positions of the GIL pipeline.... In the long distance GIL under certain conditions, this paper researches and realizes detection of PD characters and accurate fault localization through UHF coupling sensors at different positions of the GIL pipeline. The main methods for the detection are UHF signal amplitude difference (DOA) and time difference (TOF). We analyze the localization error by using TE and TEM component and high order TE mode component in electromagnetic coaxial wave guide theory. Research and field test prove the DOA detection error can meet the requirements of real-time online diagnosis and for history tracking analysis. The error of TOF detection method can be controlled within 3% and can be applied to the site. 展开更多
关键词 GIL partial discharge UHF EM-wave amplitude difference time difference fault localization.
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The Constitution and Working Mechanism of the Fast Fashion Enterprise Financial Competitiveness
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作者 YANG Guang 《International English Education Research》 2015年第10期81-83,共3页
With the Pearson Correlation Coefficient measurement method, this paper studies the correlation between the various elements influencing the financial competitiveness of the fast fashion enterprieses and the long-term... With the Pearson Correlation Coefficient measurement method, this paper studies the correlation between the various elements influencing the financial competitiveness of the fast fashion enterprieses and the long-term financial stability, which shows that the financial resilience has the biggest correlation with the long-term financial stability, which is followed in sequence by financial management capacity, financial resources capacity, financial performance capacity, and financial activity capacity. This is due to the fact that such factors as financial solvency, financial operations, profitability, growth capacity and the ability to generate cash exert effect upon the long-term stability of the financial competitiveness. 展开更多
关键词 fast fashion financial competitiveness financial resilience
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