排序方式: 共有142条查询结果,搜索用时 250 毫秒
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We propose a novel kind of compound permanent magnet synchronous machine (CPMSM), which is applicable in low-speed and high-torque situations. We first explain the structure of the CPMSM. Based on theoretically deducing the calculation formulae of the CPMSM electromagnetic parameters, we analyze the operating characteristics of the CPMSM, and obtain the power-angle curves and working curves. The no-load magnetic field distribution and the cogging torque are analyzed by applying the finite element method of three-dimensional (3D) magnetic fields, to determine the no-load leakage coefficient and the wave0form of the cogging torque. Furthermore, the optimal parameters of the permanent magnet for reducing the cogging torque are determined. An important application target of the CPMSM is in direct-drive pumping units. We have installed and tested a directdrive pumping unit in an existing oil well. Test results show that the power consumption of the direct-drive pumping unit driven by CPMSM is 6 1. 1% of that of the beam-pumping unit, and that the floor space and weight are only 50% of those of a beam-pumping unit. The noise output does not exceed 58 dB in a range of 1 m around the machine when the machine is 1.5 m from the ground. 相似文献
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试论"V+N"式合成词中V的语义呈现特征 总被引:1,自引:0,他引:1
张超 《贵州教育学院学报》2006,22(1):73-75
V N式合成词中,V的语义呈现决定于词素N,当N符合V的指代义的两个预设要求时,V就呈现指代义,整个词是动宾结构;当N不符合V的指代义的两个预设,反而意义上是V从属于N,那么,V就呈现指称义,整个词是偏正结构。 相似文献
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论智慧图书馆的三大特点 总被引:11,自引:2,他引:9
智慧图书馆作为未来图书馆的新模式,将成为图书馆创新发展、转型发展和可持续发展的新理念和新实践。本文论述智慧图书馆的三大特点:①互联的图书馆,具体细分为全面感知的图书馆、立体互联的图书馆、共享协同的图书馆;②高效的图书馆,具体细分为节能低碳的图书馆、灵敏便捷的图书馆、整合集群的图书馆;③便利的图书馆,具体细分为无线泛在的图书馆、就近一体的图书馆、个性互动的图书馆。智慧图书馆与数字图书馆、复合图书馆既有联系又有区别。 相似文献
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晁拥军 《温州职业技术学院学报》2001,1(2):38-39
本通过对渗硼层显微组织和性能的分析及渗硼后试件耐磨性的试验,研究了自保护膏剂渗硼及复合热处理工艺对工件耐磨性的影响。结论是:自保护膏剂渗硼后,进行不同温度复合热处理,表面高硬度的硼化组织与不同种类的基体组织结合,所表现出的耐磨性是不同的。 相似文献
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利用Packard的形类描写法对彝语复合词构词的结构和形类进行描写。还借鉴了其语素的四分法:功能词(自由的、功能的),根词(自由的、实义的),粘着词(粘着的、实义的),词缀(粘着的、功能的)。彝语复合词构词法类型丰富,其中名词有5种;形容词有4种;动词构词法比较单一,主要有2种;还存在一定量的多音节复合词。从构词语素的自由程度来看,无论哪种词类,主要呈根词+根词、根词语素+粘着词根语素、粘着词根语素+根词的形式。 相似文献
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李可 《山东教育学院学报》2010,25(2):90-92
通过研究复摆的运动,提出定轴转动刚体固有属性的一种表达关系。这一固有属性反映了定轴转动刚体所特有的转动惯量与质量分布有关的几何特性。解释了复摆振动中心、打击中心、能量不变点三者重合的内在原因。并进一步分析刚体定轴转动的动量与对定轴动量矩的关系,并将结论应用到实际中。 相似文献
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Compound noun segmentation is a key first step in language processing for Korean. Thus far, most approaches require some form of human supervision, such as pre-existing dictionaries, segmented compound nouns, or heuristic rules. As a result, they suffer from the unknown word problem, which can be overcome by unsupervised approaches. However, previous unsupervised methods normally do not consider all possible segmentation candidates, and/or rely on character-based segmentation clues such as bi-grams or all-length n-grams. So, they are prone to falling into a local solution. To overcome the problem, this paper proposes an unsupervised segmentation algorithm that searches the most likely segmentation result from all possible segmentation candidates using a word-based segmentation context. As word-based segmentation clues, a dictionary is automatically generated from a corpus. Experiments using three test collections show that our segmentation algorithm is successfully applied to Korean information retrieval, improving a dictionary-based longest-matching algorithm.
相似文献
Jong-Hyeok LeeEmail: |
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《中文科技期刊数据库》检索技巧探讨 总被引:1,自引:0,他引:1
通过对《中文科技期刊数据库》培训内容的整理,结合培训中使用者提出的一些问题和自己对这个数据库的使用经验及理解,比较客观地介绍了《中文科技期刊数据库》及其变化内容,讨论了字段组配检索、同义词检索和我的数据库等特殊检索功能,以帮助使用者更加熟悉这个数据库,更好地利用这个国内知名的检索工具。 相似文献