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新型定子分区式磁通切换电机的电磁性能分析 被引量:1
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作者 杨琳琳 全力 +2 位作者 朱孝勇 杜怿 项子旋 《电机与控制应用》 北大核心 2016年第5期33-37,58,共6页
提出了一种永磁体与电枢绕组分离的新型定子分区式磁通切换永磁电机。该电机包含两个定子,即带有电枢绕组的内分区定子和带有永磁体的外分区定子。基于有限元分析法分析了电机的性能,并与体积相同的传统磁通切换电机相比,该电机的电磁... 提出了一种永磁体与电枢绕组分离的新型定子分区式磁通切换永磁电机。该电机包含两个定子,即带有电枢绕组的内分区定子和带有永磁体的外分区定子。基于有限元分析法分析了电机的性能,并与体积相同的传统磁通切换电机相比,该电机的电磁转矩提高了33%。结果表明该电机采用的定子分区结构,解决了传统磁通切换电机永磁体和电枢绕组用量的冲突,使得转矩密度得到大幅度提升。 展开更多
关键词 定子分区 磁通切换 永磁电机 有限元分析
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一种新型定子分区式混合励磁电机的设计与分析(英文) 被引量:8
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作者 吴中泽 诸自强 《中国电机工程学报》 EI CSCD 北大核心 2017年第22期6543-6556,共14页
由于永磁体、励磁绕组和电枢绕组均置于唯一的定子上,传统定子励磁型混合励磁电机的转矩密度受到了限制。提出一种具有更高转矩密度的新型定子分区式混合励磁电机。在该电机中,励磁源(永磁体、励磁绕组)和电枢绕组被分别置于两个定子区... 由于永磁体、励磁绕组和电枢绕组均置于唯一的定子上,传统定子励磁型混合励磁电机的转矩密度受到了限制。提出一种具有更高转矩密度的新型定子分区式混合励磁电机。在该电机中,励磁源(永磁体、励磁绕组)和电枢绕组被分别置于两个定子区域,而转子由调制块组成。从弱磁能力、转矩提升能力和纯永磁转矩三方面综合考虑,设计了电机的尺寸参数,并分析了电机的电磁性能。通过在内区定子上引入磁桥,所提出的定子分区式混合励磁电机的弱磁能力可从12.8%增强到79.4%,而转矩提升能力可从12.1%增强到79.1%。制作了一台样机,在样机上测试了空载反电势和静态转矩,实验结果与有限元分析结果吻合。 展开更多
关键词 磁通调节能力 弱磁能力 混合励磁 定子分区 转子调制块 转矩提升能力
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Screening of the Gene for Chlorella Identification and Identification of oil-producing Microalgae 被引量:2
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作者 何茹 刘君寒 +1 位作者 王士安 李福利 《Agricultural Science & Technology》 CAS 2011年第6期795-798,共4页
[Objective] The aim was to select suitable gene for Chlorella identification and to identify the oil-producing microalgae.[Method] Four candidate gene sequences,the nuclear genomic rDNA of the 18S rRNA gene,internal t... [Objective] The aim was to select suitable gene for Chlorella identification and to identify the oil-producing microalgae.[Method] Four candidate gene sequences,the nuclear genomic rDNA of the 18S rRNA gene,internal transcribed spacer(ITS),internal transcribed spacer Ⅱ(ITS Ⅱ)and the chloroplast rbcL gene,were selected for Chlorella molecular identification.Through these four candidate genes,the genetic variability and distinguish ability between intra-species and inter-species was analyzed to choose the right genes for identification of the high oil-content Chlorella.On this basis,application of these gene segments were classified and identified for five fresh-water isolated Chlorella,which oil-content is more than 30%.[Result] ITS gene was a suitable gene because of its high variation and short fragment length,meanwhile its genetic distance intra-species(0.439 6±0.135 9)was larger than inter-species(0.045 7±0.084 3).Its sequence length varied between different species whereas highly conserved in the same species.By the application of ITS sequences,respectively,five high oil-content stains were identified as one C.vulgaris,two strains of C.sorokiniana and two strains of algae Chlorella sp.[Conclusion] This study had provided reference for the establishment of identification gene pool of Chlorella. 展开更多
关键词 Oil-producing microalgae Molecular identification Internal transcribed spacers 18S rRNA gene Genetic distance
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Molecular Characterization of Viral G Gene in Emerging and Re-emerging Areas of Rabies in China, 2007 to 2011 被引量:20
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作者 Shu-LinLang Xiao—YanTao +5 位作者 Zhen-YangGuo QingTang HaoLi Cui.PingYin YingLi Guo—DongLiang 《Virologica Sinica》 SCIE CAS CSCD 2012年第3期194-203,共10页
In recent years (2007 to 2011), although the overall number of rabies cases in China has decreased, there is evidence of emerging or re-emerging cases in regions without previous rabies cases or with low incidence of ... In recent years (2007 to 2011), although the overall number of rabies cases in China has decreased, there is evidence of emerging or re-emerging cases in regions without previous rabies cases or with low incidence of rabies. To investigate the origin and the factors affecting the spread of rabies in China, specimens were collected from 2007 to 2011 from provinces with emerging and re-emerging cases and tested for the presence of the rabies virus. Positive specimens were combined with sequences from GenBank to perform comparisons of homology and functional sites, and to carry out phylogenetic analyses. Out of these regions, five provinces had 9 positive specimens from canine and cattle, and 34 canine or human specimens were obtained from previously high-incidence provinces. Complete sequences of G gene were obtained for these samples. Homology of the sequences of these 43 specimens was 87%-100% at the nucleotide level and 93.7% -100% at the amino acid level. These G gene sequences were combined with reference sequence from GenBank and used to construct a phylogenetic tree. The results showed that 43 specimens were all assigned to China clade I and clade II, with all specimens from emerging and re-emerging areas placed within clade I. Specimens isolated from Shanxi and Inner Mongolia in 2011 were distinct from previously-isolated local strains and had closer homology to strains from Hebei, Beijing and Tianjin whereas new isolates from Shanghai were tightly clustered with strains isolated in the 1990s. Finally, Shaanxi isolates were clustered with strains from adjacent Sichuan. Our results suggest that the rabies cases in emerging and re-emerging areas in China in the last 5 years are a consequence of the epidemic spreading from of neighboring provinces and regions experiencing a serious epidemic of rabies. 展开更多
关键词 Rabies virus G gene Genetic variation Molecular characteristics
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Morphology and Molecular Identification of Ulva Forming Green Tides in Qingdao,China
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作者 KONG Fanna MAO Yunxiang +2 位作者 CUI Fujun ZHANG Xingkui GAO Zhen 《Journal of Ocean University of China》 SCIE CAS 2011年第1期73-79,共7页
Green tides are caused by the proliferation of chlorophytes under suitable hydrographic conditions.These blooms lead to environmental degradation and negatively impact the waters and seagrass beds,as well as fishing a... Green tides are caused by the proliferation of chlorophytes under suitable hydrographic conditions.These blooms lead to environmental degradation and negatively impact the waters and seagrass beds,as well as fishing and other recreational activities in the bay.A comprehensive ecological understanding of the bloom dynamics,including the origin and persistence,is needed to foster management decisions.The algae in the great majority of green tide blooms usually belong to two genera of Ulvophyceae,Ulva and Enteromorpha.Ulva has been observed more often in recent years.In China,green tides occurred for the first time in the middle area of the Yellow Sea in 2007,and a large-scale algae blooming broke out in the middle and southern areas of the Yellow Sea in late May 2008.We identified them as Ulva prolifera by comparative analysis of the rDNA internal transcribed spacer 1 (ITS1),5.8S and ITS2 sequences in combination with microscopic observation.Morphological differences were found between the free-floating algae and the attached thalli.Various reproduction patterns of the free-floating algae include sexual,asexual and vegetative propagations,which played important roles in the long-term green tide persistence in China.The ITS sequences of the blooming algae were identical to those of the samples from the Lianyungang sea area but were different from the attached samples from the Qingdao sea area.The results infer that the blooms are originated from other sea areas rather than from the local attached populations. 展开更多
关键词 Ulva prolifera green tides ITS sequences monostromatic phylogenetic analysis
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