CRISPR-Cas (clustered regularly interspaced short palindromic repeats—CRISPR associated proteins) is a RNA-guided defense immune system that prevents some genetic elements such as plasmids and virus from getting into...CRISPR-Cas (clustered regularly interspaced short palindromic repeats—CRISPR associated proteins) is a RNA-guided defense immune system that prevents some genetic elements such as plasmids and virus from getting into the bacterial cells. Zymomonas mobilis is an ethanologenic bacterium, which encodes a subtype I-F CRISPR-Cas system containing three CRISPR loci and a far distant cas gene cluster. Reverse transcription (RT)-PCR analysis revealed that the CRISPR loci were transcribed on both strands. The Cas proteins were suggested to be expressed based on the previous transcriptomic analysis. Challenging with the invader plasmids containing the artificial protospacer with the protospacer adjacent motif (PAM) of NGG or GG exhibited immune interference activity. However, PAM motif of GG seems more effective than NGG in interference activity. Further, the artificial CRISPR arrays with the spacer sequences targeting to the specific genome sites could also lead to strong immune activity, resulting in almost no transformant grown on the agar plates. It was suggested that bacteria like Z. mobilis ZM4 are lack of the rejoining function to heal the double breakage of genomic DNA made by the CRISPR system. Conclusively, the Type I-F CRISPR-Cas system in Z. mobilis ZM4 is active to functionally defense the invading DNA elements.展开更多
为了获取日光温室条件下葡萄植株的高精度绿色分数,利用高通量植物表型监测平台获取葡萄植株全生育期不同生长部位的RGB图像,分别比较迭代法、大津法和直方图双峰法得到其阈值的提取精度,从而筛选确定RGB图像最佳阈值分割方法,并利用差...为了获取日光温室条件下葡萄植株的高精度绿色分数,利用高通量植物表型监测平台获取葡萄植株全生育期不同生长部位的RGB图像,分别比较迭代法、大津法和直方图双峰法得到其阈值的提取精度,从而筛选确定RGB图像最佳阈值分割方法,并利用差异植被指数(visible-band difference vegetation index,VDVI)、过绿指数(excess green,EXG)和植被颜色提取指数(color index of vegetation,CIVE)共3种植被指数分别结合半径为5像素的圆盘形结构元得到的先闭后开形态学滤波方法,对不同生育期及不同生长部位的绿色分数信息进行提取,并对其提取精度进行分析。结果表明:利用大津法进行阈值分割误差率最小(6.5%),匹配率最高(97.78%),且提取精度高于其他两种方法;通过对葡萄底部冠层图像的绿色分数进行精度比较,发现在萌芽期和抽蔓期,CIVE指数提取精度最高,相对提取误差仅为8.45%和5.27%,而在开花坐果期、浆果膨大期和着色成熟期则采用EXG指数提取效果最佳,提取误差在0.56%~6.39%;在葡萄的不同生长部位,采用CIVE和EXG结合的分段提取法,提取效果均优于单一方法确定的绿色分数,并且在不同部位绿色分数提取精度存在差异,其中冠层中下部、底部精度较高(d>0.944),中上部和顶部稍差,但模型的一次性指数均≥0.940。研究结果可为衡量温室内植株冠层分布提供一种有效途径。展开更多
近年来,伴随着人工智能的发展及法院裁判文书的公开化,"智慧司法"、案例推荐成为热点问题.针对案例推荐中存在的推荐准确性差、传统知识图谱向量化表示精度不高等问题,提出基于知识图谱的案件推荐(Knowledge Graph based Case...近年来,伴随着人工智能的发展及法院裁判文书的公开化,"智慧司法"、案例推荐成为热点问题.针对案例推荐中存在的推荐准确性差、传统知识图谱向量化表示精度不高等问题,提出基于知识图谱的案件推荐(Knowledge Graph based Case Recommendation,KGCR)模型.该模型以知识图谱为辅助信息,利用文本分类和信息抽取技术构建面向刑事案例的知识图谱,针对当事人的陈词供述,利用知识表示学习求解相似的案件,进一步实现法条推荐.针对TransH算法的负采样问题进行改进,提出FU-TransH算法模型.以公开的刑事判决书为数据集进行实验,实验结果表明,与相关的具有代表性的算法相比,该算法的推荐准确率更高.展开更多
特高压并联电抗器隔声装置的研制有助于特高压交流变电站的噪声治理。为此分析了特高压并联电抗器的噪声特性,通过结构设计、声学设计及密封设计研制了1台高性能隔声装置,该装置采用多层隔/吸声复合结构,显著提升了声学性能。通过试验...特高压并联电抗器隔声装置的研制有助于特高压交流变电站的噪声治理。为此分析了特高压并联电抗器的噪声特性,通过结构设计、声学设计及密封设计研制了1台高性能隔声装置,该装置采用多层隔/吸声复合结构,显著提升了声学性能。通过试验验证了该隔声装置的声学性能,结果表明所得插入损失为31.8 d B,可有效地抑制中低频噪声;多物理场耦合仿真结果也表明该高性能隔声装置的插入损失可达32.1 d B,进一步验证了该隔声装置达到了预期设计目标。展开更多
文摘CRISPR-Cas (clustered regularly interspaced short palindromic repeats—CRISPR associated proteins) is a RNA-guided defense immune system that prevents some genetic elements such as plasmids and virus from getting into the bacterial cells. Zymomonas mobilis is an ethanologenic bacterium, which encodes a subtype I-F CRISPR-Cas system containing three CRISPR loci and a far distant cas gene cluster. Reverse transcription (RT)-PCR analysis revealed that the CRISPR loci were transcribed on both strands. The Cas proteins were suggested to be expressed based on the previous transcriptomic analysis. Challenging with the invader plasmids containing the artificial protospacer with the protospacer adjacent motif (PAM) of NGG or GG exhibited immune interference activity. However, PAM motif of GG seems more effective than NGG in interference activity. Further, the artificial CRISPR arrays with the spacer sequences targeting to the specific genome sites could also lead to strong immune activity, resulting in almost no transformant grown on the agar plates. It was suggested that bacteria like Z. mobilis ZM4 are lack of the rejoining function to heal the double breakage of genomic DNA made by the CRISPR system. Conclusively, the Type I-F CRISPR-Cas system in Z. mobilis ZM4 is active to functionally defense the invading DNA elements.
文摘为了获取日光温室条件下葡萄植株的高精度绿色分数,利用高通量植物表型监测平台获取葡萄植株全生育期不同生长部位的RGB图像,分别比较迭代法、大津法和直方图双峰法得到其阈值的提取精度,从而筛选确定RGB图像最佳阈值分割方法,并利用差异植被指数(visible-band difference vegetation index,VDVI)、过绿指数(excess green,EXG)和植被颜色提取指数(color index of vegetation,CIVE)共3种植被指数分别结合半径为5像素的圆盘形结构元得到的先闭后开形态学滤波方法,对不同生育期及不同生长部位的绿色分数信息进行提取,并对其提取精度进行分析。结果表明:利用大津法进行阈值分割误差率最小(6.5%),匹配率最高(97.78%),且提取精度高于其他两种方法;通过对葡萄底部冠层图像的绿色分数进行精度比较,发现在萌芽期和抽蔓期,CIVE指数提取精度最高,相对提取误差仅为8.45%和5.27%,而在开花坐果期、浆果膨大期和着色成熟期则采用EXG指数提取效果最佳,提取误差在0.56%~6.39%;在葡萄的不同生长部位,采用CIVE和EXG结合的分段提取法,提取效果均优于单一方法确定的绿色分数,并且在不同部位绿色分数提取精度存在差异,其中冠层中下部、底部精度较高(d>0.944),中上部和顶部稍差,但模型的一次性指数均≥0.940。研究结果可为衡量温室内植株冠层分布提供一种有效途径。
文摘近年来,伴随着人工智能的发展及法院裁判文书的公开化,"智慧司法"、案例推荐成为热点问题.针对案例推荐中存在的推荐准确性差、传统知识图谱向量化表示精度不高等问题,提出基于知识图谱的案件推荐(Knowledge Graph based Case Recommendation,KGCR)模型.该模型以知识图谱为辅助信息,利用文本分类和信息抽取技术构建面向刑事案例的知识图谱,针对当事人的陈词供述,利用知识表示学习求解相似的案件,进一步实现法条推荐.针对TransH算法的负采样问题进行改进,提出FU-TransH算法模型.以公开的刑事判决书为数据集进行实验,实验结果表明,与相关的具有代表性的算法相比,该算法的推荐准确率更高.
文摘特高压并联电抗器隔声装置的研制有助于特高压交流变电站的噪声治理。为此分析了特高压并联电抗器的噪声特性,通过结构设计、声学设计及密封设计研制了1台高性能隔声装置,该装置采用多层隔/吸声复合结构,显著提升了声学性能。通过试验验证了该隔声装置的声学性能,结果表明所得插入损失为31.8 d B,可有效地抑制中低频噪声;多物理场耦合仿真结果也表明该高性能隔声装置的插入损失可达32.1 d B,进一步验证了该隔声装置达到了预期设计目标。
