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31.
The development of Pt‐free catalysts for the alkaline hydrogen evolution reaction (HER), which is widely used in industrial scale water‐alkali electrolyzers, remains a contemporary and pressing challenge. Ruthenium (Ru) has excellent water‐dissociation abilities and could be an alternative water splitting catalyst. However, its large hydrogen binding energy limits HER activity. Here, a new approach is proposed to boost the HER activity of Ru through uniform loading of Ru nanoparticles on triazine‐ring (C3N3)‐doped carbon (triNC). The composite (Ru/triNC) exhibits outstanding HER activity with an ultralow overpotential of ≈2 mV at 10 mA cm?2; thereby making it the best performing electrocatalyst hitherto reported for alkaline HER. The calculated metal mass activity of Ru/triNC is >10 and 15 times higher than that of Pt/C and Pt/triNC. Both theoretical and experimental studies reveal that the triazine‐ring is a good match for Ru to weaken the hydrogen binding on Ru through interfacial charge transfer via increased contact electrification. Therefore, Ru/triNC can provide the optimal hydrogen adsorption free energy (approaching zero), while maintaining the strong water‐dissociation activity. This study provides a new avenue for designing highly efficient and stable electrocatalysts for water splitting.  相似文献   
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芍药是乙烯敏感型花卉,乙烯受体感知并传导乙烯信号,在乙烯信号转导途径中发挥重要作用。芍药PlETR1基因cDNA全长序列已分离,为了鉴定芍药PlETR1基因的功能,本研究基于PlETR1基因和表达载体序列,应用Primer Premier 5.0软件设计了一对特异性PCR引物,采用RT-PCR技术扩增出了PlETR1编码区片段,进一步构建了芍药PlETR1基因过表达载体。基于优化的模式植物烟草的组培体系和筛选出的潮霉素抗性浓度,应用农杆菌介导的叶盘法开展了芍药PlETR1基因转化烟草的研究,对转基因抗性烟草植株进行了PCR检测,结果表明HPT基因和芍药PlETR1基因已导入到烟草基因组中,且芍药PlETR1基因转录表达成功,为下一步鉴定芍药PlETR1基因的功能提供科学依据。  相似文献   
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基于组合评价法的湖南省农业可持续发展区域分异   总被引:1,自引:0,他引:1  
谭洁  董俐  周卫军  谭雪兰  刘沛 《生态科学》2020,39(1):110-117
从农业资源与环境、农业生产与经济、农业人口与社会3个评价维度构建了区域农业可持续发展指标体系, 运用主成分分析法、熵值法、模糊Borda法、因子分析法及聚类分析法和GIS技术, 通过组合评价方法定量研究湖南省农业可持续发展区域分异现状。结果表明: 湖南省农业可持续发展在区域上总体呈现出不平衡的发展状态, 农业可持续发展综合水平以长株潭城市群为核心, 由东至西递减; 农业人口与社会可持续发展水平南北低中部高, 东部强西部弱; 农业生产与经济可持续发展水平围绕湘北洞庭湖农业区和湘南农业综合区向外围递减; 农业资源与环境可持续发展水平表现为一横两纵优势带和南北两个落后圈。  相似文献   
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Wilms' tumor, also known as nephroblastoma, is a kind of pediatric renal cancer. Previous studies have indicated that microRNAs (miRNAs) regulate various cancers progression. However, whether miR‐200 family regulated Wilms' tumor progression remains to be elucidated. In our study, miR‐200b/c/429 expression was downregulated in Wilms' tumor tissue samples from 25 patients. And data from three independent analyses of quantitative real‐time polymerase chain reaction revealed that the expression of miR‐200b/c/429 was downregulated in Wilms' tumor cell lines. Functionally, Cell counting kit‐8 assay revealed that cell viability was reduced by overexpressing miR‐200b/c/429. Transwell assay manifested that cell migration and invasion was hindered by miR‐200b/c/429 overexpression. Sphere‐forming and western blot assays demonstrated that miR‐200b/c/429 overexpression suppressed the sphere formation ability. Mechanically, nuclear factor‐κB (NF‐κB) pathway was confirmed to be associated with Wilms' tumor progression; miR‐200b/c/429 overexpression inactivated NF‐κB pathway as miR‐200b/c/429 was identified to target IκB kinase β (IKK‐β), an NF‐κB pathway‐related gene. Moreover, miR‐200b/c/429 was sponged by LINC00667 in Wilms' tumor cells. LINC00667 competitively bound with miR‐200b/c/429 to regulate IKK‐β expression and then activated NF‐κB pathway in Wilms' tumor. Subsequently, rescue assays illustrated that silencing of IKK‐β could reverse the effect of miR‐200b/c/429 inhibition on the progression of sh‐LINC00667‐transfected Wilms' tumor cells. In summary, LINC00667 promoted Wilms' tumor progression by sponging miR‐200b/c/429 family to regulate IKK‐β.  相似文献   
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Chimonanthus salicifolius, a member of the Calycanthaceae of magnoliids, is one of the most famous medicinal plants in Eastern China. Here, we report a chromosome‐level genome assembly of Csalicifolius, comprising 820.1 Mb of genomic sequence with a contig N50 of 2.3 Mb and containing 36 651 annotated protein‐coding genes. Phylogenetic analyses revealed that magnoliids were sister to the eudicots. Two rounds of ancient whole‐genome duplication were inferred in the Csalicifolious genome. One is shared by Calycanthaceae after its divergence with Lauraceae, and the other is in the ancestry of Magnoliales and Laurales. Notably, long genes with > 20 kb in length were much more prevalent in the magnoliid genomes compared with other angiosperms, which could be caused by the length expansion of introns inserted by transposon elements. Homologous genes within the flavonoid pathway for Csalicifolius were identified, and correlation of the gene expression and the contents of flavonoid metabolites revealed potential critical genes involved in flavonoids biosynthesis. This study not only provides an additional whole‐genome sequence from the magnoliids, but also opens the door to functional genomic research and molecular breeding of Csalicifolius.  相似文献   
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