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南宋陈长方《步里客谈》辑佚与校勘
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作者 张诗曼 《四川图书馆学报》 2024年第1期94-100,共7页
南宋学者陈长方所撰《步里客谈》,存陈长方对历史人物之品评、诗文评等,对宋史研究有参考价值。今通行本《步里客谈》为四库馆臣从《永乐大典》辑出,并《说郛》本佚文,共58条汇编而成。然而,陈长方之学说流布甚广,在《古今源流至论》《... 南宋学者陈长方所撰《步里客谈》,存陈长方对历史人物之品评、诗文评等,对宋史研究有参考价值。今通行本《步里客谈》为四库馆臣从《永乐大典》辑出,并《说郛》本佚文,共58条汇编而成。然而,陈长方之学说流布甚广,在《古今源流至论》《戒子通录》《馀师录》《野客丛书》《永乐大典》等古籍中仍存散佚之文,未被四库馆臣注意。又《步里客谈》辑本较多文字讹误,亦指出一二。 展开更多
关键词 步里客谈》 陈长方 辑佚 校勘
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《甲种敦煌算书》的考校和释补 被引量:4
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作者 郭正忠 《自然科学史研究》 CSSCI CSCD 北大核心 2002年第1期1-11,共11页
半个多世纪以前,李俨先生曾多次介绍和研究《甲种敦煌算书》,将其断为唐代作品而详加释补。该文在校读原件后,认为该写本残卷当属于北朝敦煌算书,并在充分肯定和全面评价前人释补工作的基础上,就原卷各题内容、运算细节和字体风格等方... 半个多世纪以前,李俨先生曾多次介绍和研究《甲种敦煌算书》,将其断为唐代作品而详加释补。该文在校读原件后,认为该写本残卷当属于北朝敦煌算书,并在充分肯定和全面评价前人释补工作的基础上,就原卷各题内容、运算细节和字体风格等方面加以辨析,重新校释,力求使这部一千四五百年前的珍贵文献展现原貌。 展开更多
关键词 北朝敦煌算书写本 《甲种敦煌算书》 步里古法 黄男 (百升)
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Joint Timing and Frequency Synchronization for OFDM based on Fractional Fourier Transform 被引量:5
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作者 Tang Xun Sha Xuejun 《China Communications》 SCIE CSCD 2010年第5期93-102,共10页
In this paper a joint timing and frequency synchronization method based on Fractional Fourier Transform (FIFT) is proposed for Orthogonal Frequency-Division Multiplexing (OFDM) system. The combination of two chirp... In this paper a joint timing and frequency synchronization method based on Fractional Fourier Transform (FIFT) is proposed for Orthogonal Frequency-Division Multiplexing (OFDM) system. The combination of two chirp signals with opposite chirp rates are used as the training signal, the received training signal with timing and frequency offset is transformed by FrFT and the two peaks representing two chirps in FrFT domain are detected, then the position coordinates of the two peaks are precisely corrected and substituted into an equation group to calculate timing and frequency offset simultaneously. This method only needs one FrFT calculation to implement synchronization, the computational complexity is equal to that of FFT and less than that of correlation or maximum likelihood calculation of existing methods, and estimation range of frequency offset is Large, greater than half the signal bandwidth, while the simulation results show that even at low SNR it can accurately estimate timing and frequency offset and the estimation error is less than that of existing methods. 展开更多
关键词 SYNCHRONIZATION Fractional Fourier transform chirp signal OFDM
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Fourier and wavelet transformations application to fault detection of induction motor with stator current 被引量:6
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作者 LEE Sang-hyuk 王一奇 SONG Jung-il 《Journal of Central South University》 SCIE EI CAS 2010年第1期93-101,共9页
Fault detection of an induction motor was carried out using the information of the stator current. After synchronizing the actual data, Fourier and wavelet transformations were adopted in order to obtain the sideband ... Fault detection of an induction motor was carried out using the information of the stator current. After synchronizing the actual data, Fourier and wavelet transformations were adopted in order to obtain the sideband or detail value characteristics under healthy and various faulty operating conditions. The most reliable phase current among the three phase currents was selected using an approach that employs the fuzzy entropy measure. Data were trained with a neural network system, and the fault detection algorithm was verified using the unknown data. Results of the proposed approach based on Fourier and wavelet transformations indicate that the faults can be properly classified into six categories. The training error is 5.3×10-7, and the average test error is 0.103. 展开更多
关键词 Fourier transformation wavelet transformation induction motor fault detection
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A Study on the Structure of Linear Synchronous Motor for 600 km/h Very High Speed Train
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作者 Chan-Bae Park Byung-Song Lee 《Journal of Energy and Power Engineering》 2014年第2期374-378,共5页
Recently, an interest in a hybrid system combining only the merits of the conventional wheel-rail system and Maglev propulsion system is growing as an alternative to high-speed maglev train. This hybrid-type system is... Recently, an interest in a hybrid system combining only the merits of the conventional wheel-rail system and Maglev propulsion system is growing as an alternative to high-speed maglev train. This hybrid-type system is based on wheel-rail method, but it enables to overcome the speed limitation by adhesion because it is operated through a non-contact method using a linear motor as a propulsion system and reduce the overall construction costs by its compatibility with the conventional railway systems. Therefore, a comparative analysis on electromagnetic characteristics according to the structural combinations on the stator-mover of LSM (linear synchronous motor) for VHST (very high speed train) maintaining the conventional wheel-rail method is conducted, and the structure of coreless superconducting LSM suitable for 600 km/h VHST is finally proposed in this paper. 展开更多
关键词 Very high speed train linear synchronous motor CORELESS SUPERCONDUCTIVITY wheel-rail.
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Abbe Guinot: Teaching Logic during the 18th Century to Increase Scientific Abilities
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作者 Olivier Perru 《Journal of Philosophy Study》 2015年第6期297-301,共5页
In 1778, Abbe Guinot, a priest native of Lorraine and professor in the seminary of Toul, published in Nancy the two volumes of his philosophical lectures, whose subtitle is "On Logic." This concerns a general philos... In 1778, Abbe Guinot, a priest native of Lorraine and professor in the seminary of Toul, published in Nancy the two volumes of his philosophical lectures, whose subtitle is "On Logic." This concerns a general philosophy of knowledge and a critic of philosophical systems. Guinot is interested in science and natural discoveries. He describes the organization of institutional science and appreciates the progress of sciences but he makes a distinction between scientific progress and philosophers' sophisms that he criticizes. In order to favor science and avoid philosophical errors, logic is essential in students' training. According to Guinot, logic allows us to extend our intellectual abilities, upliR our ideas, help our thought processes, and mature our reflection. However, this logic refers to the great book of nature written in mathematical language. Guinot thinks that scientific experiment is of the highest importance for accuracy of mind. This logic lecture is inspired by Aristotle but above all by Port-Royal Logic. It gives a place to Locke empiricism and it favors development of sciences. Abbe Guinot was a chaplain in the cathedral of Nancy; he emigrated in 1791. He came back in France during the Consulate and he died a few time later. 展开更多
关键词 LOGIC 18th century education Port-Royal Logic
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On the Gibbs Phenomenon of Fourier Series of a Classical Function 被引量:1
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作者 XIANG Xue Yan HE Qian 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2008年第2期347-352,共6页
In this paper,we point out that the Fourier series of a classical function∑^∞k=1 sin kx/k has the Gibbs phenomenon in the neighborhood of zero.Furthermore,we estimate the upper bound of its partial sum and get:sup ... In this paper,we point out that the Fourier series of a classical function∑^∞k=1 sin kx/k has the Gibbs phenomenon in the neighborhood of zero.Furthermore,we estimate the upper bound of its partial sum and get:sup n≥1||∑^n k=1sin kx/k||=∫^x 0sin x/x dx=1.85194, which is better than that in[1]. 展开更多
关键词 Fourier series partial sum upper bound.
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