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反射定律的三种表达形式 被引量:9
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作者 欧家鸣 王瑞丽 +2 位作者 尚鹤岑 白凤翔 张书练 《云南师范大学学报(自然科学版)》 2000年第1期57-61,共5页
本文从现代光学角度,对比分析了反射定律的标量表达、矢量表达和矩阵表达,并以角锥棱镜的反射特性研究为例,进一步阐述了矩阵表达在现代几何光学中的突出优势。该研究在激光动镜谐振腔的应用中有极为重要的意义。借此对比,意在说明,现... 本文从现代光学角度,对比分析了反射定律的标量表达、矢量表达和矩阵表达,并以角锥棱镜的反射特性研究为例,进一步阐述了矩阵表达在现代几何光学中的突出优势。该研究在激光动镜谐振腔的应用中有极为重要的意义。借此对比,意在说明,现代光学的发展,要求加大光学基础课程改革的力度。 展开更多
关键词 反射定律 标量表达 矢量表达 矩阵表达
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Comparative mapping of QTLs for Al tolerance in rice and identification of positional Al-induced genes 被引量:7
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作者 毛传澡 杨玲 +4 位作者 郑炳松 吴运荣 刘非燕 易可可 吴平 《Journal of Zhejiang University Science》 EI CSCD 2004年第6期634-643,共10页
Aluminum (Al) toxicity is the major factor limiting crop productivity in acid soils. In this study, a recombinant inbreed line (RIL) population derived from a cross between an Al sensitive lowland indica rice variety... Aluminum (Al) toxicity is the major factor limiting crop productivity in acid soils. In this study, a recombinant inbreed line (RIL) population derived from a cross between an Al sensitive lowland indica rice variety IR1552 and an Al tolerant upland japonica rice variety Azucena, was used for mapping quantitative trait loci (QTLs) for Al tolerance. Three QTLs for relative root length (RRL) were detected on chromosome 1, 9, 12, respectively, and 1 QTL for root length under Al stress is identical on chromosome 1 after one week and two weeks stress. Comparison of QTLs on chromosome 1 from different studies indicated an identical interval between C86 and RZ801 with gene(s) for Al tolerance. This interval provides an important start point for isolating genes responsible for Al tolerance and understanding the genetic nature of Al tolerance in rice. Four Al induced ESTs located in this interval were screened by reverse Northern analysis and confirmed by Northern analysis. They would be candidate genes for the QTL. 展开更多
关键词 Aluminum tolerance Quantitative trait loci (QTL) Expressed sequence tag (EST) Gene Rice (Oryza sativa L.)
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关于线速度、角速度和向心加速度的讨论
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作者 周复忠 《湖南中学物理》 2020年第4期74-75,共2页
本文通过对线速度定义、角速度和向心加速度意义、速度变化量的影响因素等问题的讨论帮助学生解决学习过程中的困惑,纠正师生相关问题认识上的偏差,进而引发教师对日常教学的思考。
关键词 线速度 角速度 向心加速度 矢量表达 标量表达 矢量变化量
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High-throughput sequencing-based genome-wide identification of micro RNAs expressed in developing cotton seeds 被引量:7
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作者 WANG YanMei DING Yan +2 位作者 YU DingWei XUE Wei LIU JinYuan 《Science China(Life Sciences)》 SCIE CAS CSCD 2015年第8期778-786,共9页
Micro RNAs(mi RNAs) have been shown to play critical regulatory roles in gene expression in cotton. Although a large number of mi RNAs have been identified in cotton fibers, the functions of mi RNAs in seed developmen... Micro RNAs(mi RNAs) have been shown to play critical regulatory roles in gene expression in cotton. Although a large number of mi RNAs have been identified in cotton fibers, the functions of mi RNAs in seed development remain unexplored. In this study, a small RNA library was constructed from cotton seeds sampled at 15 days post-anthesis(DPA) and was subjected to high-throughput sequencing. A total of 95 known mi RNAs were detected to be expressed in cotton seeds. The expression pattern of these identified mi RNAs was profiled and 48 known mi RNAs were differentially expressed between cotton seeds and fibers at 15 DPA. In addition, 23 novel mi RNA candidates were identified in 15-DPA seeds. Putative targets for 21 novel and 87 known mi RNAs were successfully predicted and 900 expressed sequence tag(EST) sequences were proposed to be candidate target genes, which are involved in various metabolic and biological processes, suggesting a complex regulatory network in developing cotton seeds. Furthermore, mi RNA-mediated cleavage of three important transcripts in vivo was validated by RLM-5′ RACE. This study is the first to show the regulatory network of mi RNAs that are involved in developing cotton seeds and provides a foundation for future studies on the specific functions of these mi RNAs in seed development. 展开更多
关键词 Gossypium hirsutum seed development microRNA (miRNA) target gene GO annotation high-throughput sequencing
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