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Identification of QTL for kernel number-related traits in a rice chromosome segment substitution line and fine mapping of qSP1 被引量:3
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作者 Fuying Ma Xiaoyan Zhu +8 位作者 Hui Wang Shiming Wang Guoqing Cui Ting Zhang Zhenglin Yang Guanghua He Yinghua Ling Nan Wang Fangming Zhao 《The Crop Journal》 SCIE CAS CSCD 2019年第4期494-503,共10页
A chromosome segment substitution line (CSSL) is a powerful tool for combining quantitative trait locus (QTL) mapping with the pyramiding of desirable alleles. The rice CSSL Z1364 with increased kernel number was iden... A chromosome segment substitution line (CSSL) is a powerful tool for combining quantitative trait locus (QTL) mapping with the pyramiding of desirable alleles. The rice CSSL Z1364 with increased kernel number was identified in a BC3F8 population derived from a cross of Nipponbare as the recipient with Xihui 18 as the donor parent. Z1364 carried three substitution segments distributed on chromosomes 1, 6, and 8. The mean substitution length was 1.19 Mb. Of 17 QTL identified on the substitution segments, qSP1 for spikelets per panicle, qSSD1 for seed-set density, and qNSB1 for number of secondary branches explained respectively 57.34%, 87.7%, and 49.44% of the corresponding phenotypic variance and were all linked to RM6777. Chi-square analysis showed that the increased kernel number in Z1364 was inherited recessively by a single gene. By fine mapping, qSP1 was delimited to a 50-kb region on the short arm of chromosome 1. Based on DNA sequence, a previously uncharacterized rice homolog of Arabidopsis thaliana AT4G32551 was identified as a candidate gene for qSP1 in which mutation increases the number of spikelets and kernels in Z1364. qSP1 was expressed in all tissues, but particularly in 1-cm panicles. The expression levels of OsMADS22, GN1A, and DST were upregulated and those of LAX2, GNP1, and GHD7 were downregulated in Nipponbare. These results provide a foundation for functional research on qSP1. 展开更多
关键词 RICE CHROMOSOME SEGMENT substitution line Increased number of KERNELS qSP1 QTL mapping for yield traits
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Determination of the Number of SSR Alleles Necessary for the Analysis of Genetic Relationships Between Maize Inbred Lines 被引量:2
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作者 WU Cheng-lai, LI Sheng-fu, DONG Bing-xue, ZHANG Qian-qian and ZHANG Chun-qing State Key Laboratory of Crop Biology/College of Agriculture, Shandong Agricultural University, Tai’an 271018, P.R.China 《Agricultural Sciences in China》 CSCD 2010年第12期1713-1725,共13页
The amount of molecular marker information has considerable impact on the results of studies of crop germplasm genetic relationships in crop. The number of alleles required to reveal genetic relationship in maize inbr... The amount of molecular marker information has considerable impact on the results of studies of crop germplasm genetic relationships in crop. The number of alleles required to reveal genetic relationship in maize inbred lines is a theoretical issue that needs to be addressed. In this study, 112 pairs of SSR (simple sequence repeat) primers and 97 maize inbred lines were selected to study the relationship between the number of inbred lines and the number of SSR primers and alleles required for a stable cluster. The results showed that the number of SSR primers is not tightly associated with the stability of the cluster analysis results, while an increase in the number of alleles can significantly improve the stability of cluster analysis results. The number of inbred lines (X) is significantly associated with the number of alleles required for stable cluster analysis (Y), and the regression equation is Y- 600.8xe(-15.9/x). This equation can be used to calculate the number of SSR alleles required for a genetic relationship study of maize inbred lines. These results provide a reference for determining of SSR alleles number in genetic relationship analysis of maize inbred line and other crop germplasm. 展开更多
关键词 MAIZE inbred line SSR number of alleles genetic relationship
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Studies on the Developmental Genetics of Tiller Number in Three-line Indica Hybrid Rice 被引量:1
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作者 LIANG Kang-jing, LIN Wen-xiong, WANG Xue-ren, CHEN Zhi-xiong, GUO Yu-chun, LIANG Yi-yuan, CHEN Fang-yu and LI Ya-juan( College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou 350002, P. R . China ) 《Agricultural Sciences in China》 CAS CSCD 2002年第8期837-844,共8页
Following NCI design, the developmental genetic behavior of tiller number (TN) in three-line indica hybrid rice was studied using additive-dominance developmental genetic models and the corresponding statistical metho... Following NCI design, the developmental genetic behavior of tiller number (TN) in three-line indica hybrid rice was studied using additive-dominance developmental genetic models and the corresponding statistical methods. The results showed that dominance effects were predominant for TN. The expression of those additive effects were affected by environment and genotype interaction, but the expression of dominance effects were not affected. Heterosis was the strongest in the middle developmental periods of TN. Additive effects and dominance effects were selectively expressed throughout in the entire tillering developmental stage. Analysis of genetic correlation between TN at different stages and the productive panicles indicated that a close correlation appeared earlier in the populations with higher heterosis than in those with less heterosis. Utilization of heterosis at the middle tillering stage might enhance the final biomass but reduce the percentage of productive panicles. 展开更多
关键词 Three-line indica hybrid rice Tiller number Developmental genetics Genetic variance HETEROSIS
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Characterization of a new hexaploid triticale 6D(6A) substitution line with increased grain weight and decreased spikelet number
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作者 Zhiyu Feng Zhongqi Qi +8 位作者 Dejie Du Mingyi Zhang Aiju Zhao Zhaorong Hu Mingming Xin Yingyin Yao Huiru Peng Qixin Sun Zhongfu Ni 《The Crop Journal》 SCIE CAS CSCD 2019年第5期598-607,共10页
Hexaploid triticale(×Triticosecale,AABBRR)is an important forage crop and a promising energy plant.Transferring D-genome chromosomes or segments from common wheat(Triticum aestivum)into hexaploid triticale is att... Hexaploid triticale(×Triticosecale,AABBRR)is an important forage crop and a promising energy plant.Transferring D-genome chromosomes or segments from common wheat(Triticum aestivum)into hexaploid triticale is attractive in improving its economically important traits.Here,a hexaploid triticale 6D(6A)substitution line Lin 456 derived from the cross between the octoploid triticale line H400 and the hexaploid wheat Lin 56 was identified and analyzed by genomic in situ hybridization(GISH),fluorescence in situ hybridization(FISH),and molecular markers.The GISH analysis showed that Lin 456 is a hexaploid triticalewith 14 rye(Secale cereale)chromosomes and 28 wheat chromosomes,whereas non-denaturing fluorescence in situ hybridization(ND-FISH)and molecular marker analysis revealed that it is a 6D(6A)substitution line.In contrast to previous studies,the signal of Oligo-pSc119.2 was observed at the distal end of 6DL in Lin 456.The wheat chromosome 6D was associatedwith increased grain weight and decreased spikelet number using the genotypic data combined with the phenotypes of the F2 population in the three environments.The thousand-grain weight and grain width in the substitution individuals were significantly higher than those in the non-substitution individuals in the F2 population across the three environments.We propose that the hexaploid triticale 6D(6A)substitution line Lin 456 can be a valuable and promising donor stock for genetic improvement during triticale breeding. 展开更多
关键词 In SITU HYBRIDIZATION SPIKELET number SUBSTITUTION line Thousand-grain weight TRITICALE
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Unconditional and Conditional QTL Mapping for Tiller Numbers at Various Stages with Single Segment Substitution Lines in Rice(Oryza sativa L.) 被引量:6
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作者 ZHAO Fang-ming LIU Gui-fu ZHU Hai-tao DING Xiao-hua ZENG Rui-zhen ZHANG Ze-min LI Wen-tao ZHANG Gui-quan 《Agricultural Sciences in China》 CAS CSCD 2008年第3期257-265,共9页
Tiller is one of the most important agronomic traits which influences quantity and quality of effective panicles and finally influences yield in rice. It is important to understand "static" and "dynamic" informati... Tiller is one of the most important agronomic traits which influences quantity and quality of effective panicles and finally influences yield in rice. It is important to understand "static" and "dynamic" information of the QTLs for tillers in rice. This work was the first time to simultaneously map unconditional and conditional QTLs for tiller numbers at various stages by using single segment substitution lines in rice. Fourteen QTLs for tiller number, distributing on the corresponding substitution segments of chromosomes 1, 2, 3, 4, 6, 7 and 8 were detected. Both the number and the effect of the QTLs for tiller number were various at different stages, from 6 to 9 in the number and from 1.49 to 3.49 in the effect, respectively. Tiller number QTLs expressed in a time order, mainly detected at three stages of 0-7 d, 14-21 d and 35-42 d after transplanting with 6 positive, 9 random and 6 negative expressing QTLs, respectively. Each of the QTLs expressed one time at least during the whole duration of rice. The tiller number at a specific stage was determined by sum of QTL effects estimated by the unconditional method, while the increasing or decreasing number in a given time interval was controlled by the total of QTL effects estimated by the conditional method. These results demonstrated that it is highly effective and accurate for mapping of the QTLs by using single segment substitution lines and the conditional analysis methodology. 展开更多
关键词 single segment substitution line unconditional QTL mapping conditional QTL mapping tiller number RICE
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The Difference of the Copy Number Variation and Loss of Heterozygosity of Human Lung Large Cell Cancer Cell Line with Different Metastatic Potential
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作者 Bin HU Xiaoming QIU Ting WANG Yu FAN Li MA Jun CHEN Sen WEI Zhigang LI Hongyu LIU Haisu WAN Zhihao WU Qinghua ZHOU 《中国肺癌杂志》 CAS 2009年第6期512-514,共3页
Background and Objective It has been proven that copy number gain/or loss (copy number variation CNV) in uences gene expression and result in phenotypic variation by
关键词 肺癌 癌细胞 CNV 治疗 疗效
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考虑Pareto最优的列车运行图与维修天窗协调优化
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作者 张哲铭 何世伟 +3 位作者 李光晔 赵子琪 王攸妙 周汉 《铁道科学与工程学报》 EI CAS CSCD 北大核心 2024年第3期949-958,共10页
列车运行图与维修天窗之间的冲突始终无法避免,且维修天窗开设时间的长短显著影响列车总运行时间。针对此问题,综合考虑维修天窗对列车运行造成的限速约束、车站到发线数量约束等,建立列车总运行时间最小,以及维修天窗实际开设时长与理... 列车运行图与维修天窗之间的冲突始终无法避免,且维修天窗开设时间的长短显著影响列车总运行时间。针对此问题,综合考虑维修天窗对列车运行造成的限速约束、车站到发线数量约束等,建立列车总运行时间最小,以及维修天窗实际开设时长与理想时长总偏差最小的双目标混合整数规划模型;对困难约束设置中间辅助变量将模型线性化以提高求解效率,并设计约束转换算法求解双目标模型的Pareto最优;微观化处理铁路线,将站内资源和站间资源细化为一系列行车资源单元,得到更加符合实际旅客运输需求的运行图。以某地区铁路线夜间开行列车及维修天窗开设计划为研究背景,调用商业软件求解双目标函数模型的Pareto最优,并对双目标模型的最小支配解和最优支配解进行对比分析;针对最优支配解下的列车进入、离开行车资源单元的时间、停站作业时间及维修天窗的开始时间及开设时长,绘制列车运行图。求解结果表明:模型在满足维修天窗最小开设时长的同时,能够兼顾列车运行总时间最小和维修天窗开设时长更充裕。基于最优支配解绘制的列车运行图表明:微观路网下的列车运行时刻表优化结果更符合实际旅客运输生产作业需要。研究结果可为铁路运营管理部门进一步优化列车运行图编制与维修天窗开设提供参考。 展开更多
关键词 铁路运输 列车运行图 维修天窗 到发线数量 约束转换算法 PARETO最优
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工位数固定的U型拆卸线部分拆卸平衡问题
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作者 吴秀丽 张兴宇 《控制理论与应用》 EI CAS CSCD 北大核心 2024年第6期1079-1088,共10页
为提高工位数固定的U型拆卸线拆卸效率,减少有害部件对操作人员的潜在威胁,针对高价值零部件和有害零部件的拆卸需求,本文提出了工位数固定的U型拆卸线部分拆卸平衡问题,建立了以最小化节拍时间、高危工位数目和负载均衡为目标的优化模... 为提高工位数固定的U型拆卸线拆卸效率,减少有害部件对操作人员的潜在威胁,针对高价值零部件和有害零部件的拆卸需求,本文提出了工位数固定的U型拆卸线部分拆卸平衡问题,建立了以最小化节拍时间、高危工位数目和负载均衡为目标的优化模型,并设计了改进的变邻域搜索算法进行求解.在编码过程中提出一种基于零部件释放位置的选择策略,以减少前继零部件拆卸顺序对编码的影响;提出最小偏差二分法,有效减少解码的迭代次数;提出瓶颈挤压局部搜索策略,用以优化节拍时间和均衡负载指标.通过与其他算法对比,结果表明改进的变邻域搜索算法求解具有优越性,并且可实现对工位数固定的U型拆卸线部分拆卸平衡问题的高效求解. 展开更多
关键词 拆卸线平衡 U型拆卸线 变邻域搜索算法 工位数固定 瓶颈挤压局部搜索策略
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数字线估计的模型与策略:有界和无界的相似与分离
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作者 李敏 孙晓辉 +1 位作者 李文杰 李梦霞 《心理研究》 2024年第4期301-307,共7页
Cohen于2011年提出了无界数字线估计任务,诸多研究表明该任务克服了传统有界数字线估计任务的局限,能够反映更加纯粹的数字表征本质。然而,无界数字线估计的模型与策略与有界数字线估计的异同,还有待检验。文章分别对有界和无界数字线... Cohen于2011年提出了无界数字线估计任务,诸多研究表明该任务克服了传统有界数字线估计任务的局限,能够反映更加纯粹的数字表征本质。然而,无界数字线估计的模型与策略与有界数字线估计的异同,还有待检验。文章分别对有界和无界数字线估计任务中的数字表征模型和估计策略进行梳理,分析两种任务中数字线表征模型以及估计策略发展与转变的相似与分离,并进一步推测估计策略与表征模型之间的关系,以期为数字认知的相关研究提供参考。 展开更多
关键词 有界数字线估计 无界数字线估计 数字表征模型 估计策略
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在线激光打孔参数对中支卷烟理化指标的影响
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作者 孙明铭 刘宏 +7 位作者 许嘉欣 卢彦华 孙强 张广喜 张新龙 李洪涛 李军 杨明峰 《安徽农业科学》 CAS 2024年第4期165-169,共5页
[目的]明确在线激光打孔参数对中支卷烟理化指标的影响,为中支卷烟激光打孔参数的设置提供借鉴。[方法]以物理指标、常规烟气成分释放量和感官质量为衡量指标,分析不同在线激光打孔参数对中支卷烟质量的影响。[结果]激光打孔数量与中支... [目的]明确在线激光打孔参数对中支卷烟理化指标的影响,为中支卷烟激光打孔参数的设置提供借鉴。[方法]以物理指标、常规烟气成分释放量和感官质量为衡量指标,分析不同在线激光打孔参数对中支卷烟质量的影响。[结果]激光打孔数量与中支卷烟吸阻呈现负相关关系(P<0.01),与滤嘴通风率、总通风率呈现正相关关系(P<0.01),与TPM、水分、焦油释放量均呈现二次回归关系。激光脉冲时间与中支卷烟吸阻、滤嘴通风率、总通风率均呈现二次回归关系,但其对常规烟气成分释放量无显著影响。激光打孔数量对中支卷烟理化指标的影响程度大于激光脉冲时间,在线激光打孔参数主要影响中支卷烟的香气量、刺激性和协调性。[结论]得到一套在线激光打孔参数和中支卷烟理化指标关系的数学模型,可应用于中支卷烟开发和产品维护中激光打孔参数的设置。 展开更多
关键词 中支卷烟 在线激光打孔参数 激光打孔数量 激光脉冲时间
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LKJ控制车站多个高速道岔限速隐患分析及对策
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作者 王树新 《铁道通信信号》 2024年第6期80-84,共5页
因早期设计的局限性,LKJ在车站区域只能调用预先编制的唯一高速道岔股道数据(126股道数据)控制列车运行。当存在多条径路有高速道岔接车时,会出现LKJ调用的高速道岔股道数据限制速度、进出岔距离与列车实际运行状况不一致的问题,存在安... 因早期设计的局限性,LKJ在车站区域只能调用预先编制的唯一高速道岔股道数据(126股道数据)控制列车运行。当存在多条径路有高速道岔接车时,会出现LKJ调用的高速道岔股道数据限制速度、进出岔距离与列车实际运行状况不一致的问题,存在安全风险。为此,结合LKJ程序控制及LKJ基础数据源文件编制原则,在排查沈阳局管内所有接入高速道岔车站走行径路的基础上,归纳出5种典型场景,结合图例针对性地分析可能存在的安全风险,采取统一高速道岔限速值、提供特殊地点说明等解决措施,并提出改变行车方式和高速股道可输入股道号的可行性方案。现场应用效果表明:该方案能够解决现有车站具备多条径路接入高速道岔的安全隐患,具有一定推广价值。 展开更多
关键词 列车运行监控装置 高速道岔 股道数据 支线号 分歧径路
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考虑最少线路切换数量的电压稳定性增强优化方法
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作者 刘建涛 王蕾 +1 位作者 邓晓帆 焦提操 《电力自动化设备》 EI CSCD 北大核心 2024年第5期217-224,共8页
为提升电力系统的电压稳定性,提出一种基于输电线路切换的电压稳定性增强控制模型,该模型以最少的切换输电线路数量为目标来满足电力系统负荷裕度的提升需求。为灵活构建线路切换数学模型,提出基于支路追加法将线路切换融入原问题模型... 为提升电力系统的电压稳定性,提出一种基于输电线路切换的电压稳定性增强控制模型,该模型以最少的切换输电线路数量为目标来满足电力系统负荷裕度的提升需求。为灵活构建线路切换数学模型,提出基于支路追加法将线路切换融入原问题模型中。为降低模型求解难度,提出一种阶段式求解策略:基于负荷裕度对线路参数的灵敏度快速预筛选出可以提高系统负荷裕度的候选切换集,降低0-1整数变量的搜索范围;基于外逼近和松弛策略将原问题分解为2个子问题进行迭代求解,进一步提高模型的求解速度和精度。IEEE118节点和IEEE662节点系统仿真结果验证了所提模型与方法的有效性。 展开更多
关键词 输电线路切换 电压稳定性 最少切换数量 支路追加法 阶段式求解策略
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晚期非小细胞肺癌患者接受盐酸安罗替尼一线和二线治疗的近期疗效观察
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作者 王敏 常宁 +1 位作者 张勇 张艰 《空军军医大学学报》 CAS 2024年第1期80-84,共5页
目的探讨无法接受化疗或靶向治疗的晚期非小细胞肺癌(NSCLC)患者在应用安罗替尼作为一线和二线治疗时的近期疗效和安全性评价,分析治疗线数与预后的潜在相关性。方法收集接受化疗或靶向治疗并接受安罗替尼单药治疗的Ⅲ/Ⅳ期NSCLC患者临... 目的探讨无法接受化疗或靶向治疗的晚期非小细胞肺癌(NSCLC)患者在应用安罗替尼作为一线和二线治疗时的近期疗效和安全性评价,分析治疗线数与预后的潜在相关性。方法收集接受化疗或靶向治疗并接受安罗替尼单药治疗的Ⅲ/Ⅳ期NSCLC患者临床信息并进行回顾性分析,共纳入69例符合入组要求的Ⅲ/Ⅳ期NSCLC患者,其中26例从未接受过抗肿瘤治疗的患者使用安罗替尼一线治疗(一线治疗组),43例化疗不耐受或靶向治疗耐药的患者接受安罗替尼二线治疗(二线治疗组)。上述患者无进展生存期(PFS)为主要评价指标,次要观察指标包括客观缓解率(ORR)、疾病控制率(DCR)以及安罗替尼的安全性等。结果69例患者的中位PFS为4.6个月(95%CI:4.21~5.00),ORR和DCR分别为15.9%和84.1%。其中,26例接受安罗替尼一线治疗患者的ORR和DCR分别为26.9%和84.6%,43例接受安罗替尼二线治疗患者的ORR和DCR分别为9.3%和83.7%。在本研究中,安罗替尼常见的毒副反应是可控的,如高血压、手足综合征和口腔黏膜炎等。结论安罗替尼对未接受过化疗或靶向治疗的Ⅲ/Ⅳ期NSCLC患者显示出初步的疗效和可耐受的安全性,安罗替尼的治疗线数可以作为PFS的独立影响因素。 展开更多
关键词 非小细胞肺癌 抗血管生成治疗 安罗替尼 治疗线数 毒副反应
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固定污染源在线监测现状与对策
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作者 马先慧 《化工管理》 2024年第16期60-63,共4页
随着国家对环境保护的日益重视,固定污染源在线监测系统作为环保管理工作中的一项关键技术,发挥着越来越重要的作用。文章对上海市某化工园区固定污染源在线监测系统开展调查及分类,按行业统计了解固定污染源在线监测现状,对其建设、运... 随着国家对环境保护的日益重视,固定污染源在线监测系统作为环保管理工作中的一项关键技术,发挥着越来越重要的作用。文章对上海市某化工园区固定污染源在线监测系统开展调查及分类,按行业统计了解固定污染源在线监测现状,对其建设、运行、联网中存在的问题进行了剖析,从采样单元、监测站房、分析及数据采集单元和运维管理情况提出可供借鉴的经验和做法。最后,建议从加强顶层设计、强化数智化监管、规范运维制度进一步规范企业在线监测运维,为持续推进固定污染源在线监测的标准化建设、规范化运行和科学化管理奠定基础。 展开更多
关键词 固定污染源 在线监测 现状 规范化 数智化
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农村低压配电网剩余电流保护及中性线断线保护的运检管理
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作者 盛平安 陈兴 《农村电气化》 2024年第4期82-85,共4页
为了保障农村客户用电安全,减小停电频次,缩小停电范围,提升农村配电网低压供电可靠性,笔者结合农村低压配电网运维管理工作经验,从实际出发总结低压配电网剩余电流保护装置及低压中性线断线保护装置运维管理等方面的经验,以供参考。
关键词 农村配电网 剩余电流保护 中性线断线保护
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基于小波包的电缆混合线路接地故障诊断方法研究
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作者 黄毅标 胡韵婷 +1 位作者 陈雄 许文宣 《电子设计工程》 2024年第13期122-125,130,共5页
发生接地故障时负载电压数值会出现明显增大的情况,根据负载电压数值变化行为,提出基于小波包的电缆混合线路接地故障诊断方法。根据小波包分解与重构原则,对故障数据实施预处理,通过求解功率预测指标的方式,完成对电缆混合线路的短期... 发生接地故障时负载电压数值会出现明显增大的情况,根据负载电压数值变化行为,提出基于小波包的电缆混合线路接地故障诊断方法。根据小波包分解与重构原则,对故障数据实施预处理,通过求解功率预测指标的方式,完成对电缆混合线路的短期故障功率预测。在故障属性集合中,判定故障行为表现特征,联合三角模糊数的计算结果,完成基于小波包的电缆混合线路接地故障诊断。对比实验结果表明,在小波包理论作用下,发生接地故障时负载电压数值达到了485 V,与非故障电压之间的差值超过100 V,电缆主机可以根据负载电压变化行为实现对混合线路接地故障行为的准确诊断。 展开更多
关键词 小波包 电缆混合线路 故障诊断 分解与重构 故障属性 三角模糊数
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Topological Aspect and Bifurcation of Disclination Lines in Two—Dimensional Liquid Crystals 被引量:2
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作者 YANGGuo-Hong ZHANGHui 《Communications in Theoretical Physics》 SCIE CAS CSCD 2002年第5期513-518,共6页
Using φ-mapping method and topological current theory, the topological structure and bifurcation ofdisclination lines in two-dimensional liquid crystals are studied. By introducing the strength density and the topolo... Using φ-mapping method and topological current theory, the topological structure and bifurcation ofdisclination lines in two-dimensional liquid crystals are studied. By introducing the strength density and the topologicalcurrent of many disclination lines, the total disclination strength is topologically quantized by the Hopf indices andBrouwer degrees at the singularities of the director field when the Jacobian determinant of director field does not vanish.When the Jacobian determinant vanishes, the origin, annihilation and bifurcation processes of disclination lines arestudied in the neighborhoods of the limit points and bifurcation points, respectively. The branch solutions at the limitpoint and the different directions of all branch curves at the bifurcation point are calculated with the conservation lawof the topological quantum numbers. It is pointed out that a disclination line with a higher strength is unstable and itwill evolve to the lower strength state through the bifurcation process. 展开更多
关键词 拓扑流 绕数 二维液体晶体 双斜线分叉
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Topological Structure of Disclination Lines in 2-Dimensional Liquid Crystals 被引量:1
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作者 张慧 杨国宏 《Journal of Shanghai University(English Edition)》 CAS 2002年第3期207-210,共4页
Using mapping method and topological current theory, the topological structure of disclination lines in 2 dimensional liquid crystals is studied. By introducing the strength density and the topological current of m... Using mapping method and topological current theory, the topological structure of disclination lines in 2 dimensional liquid crystals is studied. By introducing the strength density and the topological current of many disclination lines, it is pointed out that the disclination lines are determined by the singulaities of the director field, and topologically quantized by the Hopf indices and Brouwer degrees. Due to the equivalence in physics of the director fields n (x) and n (x) , the Hopf indices can be integers or half integers, representing a generalization of our previous studies of integer Hopf indices. 展开更多
关键词 topological current winding number director field disclination line.
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Modeling Density and Anisotropy of Energetic Electrons Along Magnetic Field Lines 被引量:3
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作者 肖伏良 冯学尚 《Plasma Science and Technology》 SCIE EI CAS CSCD 2006年第3期279-284,共6页
The electromagnetic wave growth or damping depends basically on the number density and anisotropy of energetic particles as the resonant interaction takes place between the particles and waves in the magnetosphere. Th... The electromagnetic wave growth or damping depends basically on the number density and anisotropy of energetic particles as the resonant interaction takes place between the particles and waves in the magnetosphere. The variance of both the number density and anisotropy along the magnetic field line is evaluated systematically by modeling four typically prescribed distribution functions. It is shown that in the case of "the positive anisotropy" (namely, the perpendicular temperature T⊥ exceeds the parallel temperature T||), the number density of energetic electrons always decreases with the magnetic latitude for a regular increasing magnetic field and the maximum wave growth is therefore generally confined to the equator where the resonant energy is minimum, and the number density is the largest. However, the "loss-cone" anisotropy of the electrons with a "pancake" distribution or kappa distribution keeps invariant or nearly invariant, whereas the "temperature" anisotropy with a pure bi-Maxwellian distribution or Ashour-Abdalla and Kennel's distributions decreases with the magnetic latitude. The results may provide a useful approach to evaluating the number density and anisotropy of the energetic electrons at latitudes where the observation information is not available. 展开更多
关键词 number density ANISOTROPY distribution function magnetic field line
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Comparison of QTL for Grain Number per Panicle in Three Populations Sharing 3 Parents and Fine Mapping of Gn1c
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作者 T.M. Liu  D.H. Mao  X.F. Bai  C.G. Xu Q.F. Zhang  Y.Z. Xing 《分子植物育种》 CAS CSCD 2007年第2期221-222,共2页
Complex traits, such as yield components, are inherited in a quantitative manner and typically controlled by quantitative trait loci (QTL). Grain number per panicle (GN) is an important component of yield in rice and
关键词 圆锥花序 重组体 稻子 灯基因
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