31 research outputs found

    中国極乾燥地帯における土壌水分に対するPopulus euphratica Oliv.の根の分布応答

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    Generally root systems of tree are divided into coarse root system and fine root system. As well as fine root system, coarse root system is important to well growth of tree too. Based on the data observed at Ejina Banner Inner Mongolia Autonomous Region, China from May to July of 2006, using fractal theory and statistical method, the relationship between coarse root system distribution of Populus euphratica Oliv. and soil moisture in root zone was analyzed. Root system of tree has a typical fractal characteristic. For a fractal system, its exterior form is complex, while the fractal dimension (D) is a constant. So we computed D of coarse root system and mean soil moisture (E) in root zone of each sample tree, got a function between D and E. This function shows how does the coarse root system of Populus euphratica Oliv. change in different soil moisture in root zone. So we can judge coarse root distribution of Populus euphratica Oliv. by the function. If E is less than 11.02%, then root fractal dimensions increase with E; if E is more than 11.02%, root fractal dimensions decrease with E. Based on the function, we got an interval of E, (5%, 24.5%), in which Populus euphratica Oliv. grows more well.特集 : 「資源、新エネルギー、環境、防災研究国際セミナー

    Pd/NiMoO4/NF electrocatalysts for the efficient and ultra-stable synthesis and electrolyte-assisted extraction of glycolate

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    Abstract Electrocatalytic conversion of organic small molecules is a promising technique for value-added chemical productions but suffers from high precious metal consumption, poor stability of electrocatalysts and tedious product separation. Here, a Pd/NiMoO4/NF electrocatalyst with much lowered Pd loading amount (3.5 wt.%) has been developed for efficient, economic, and ultra-stable glycolate synthesis, which shows high Faradaic efficiency (98.9%), yield (98.8%), and ultrahigh stability (1500 h) towards electrocatalytic ethylene glycol oxidation. Moreover, the obtained glycolic acid has been converted to value-added sodium glycolate by in-situ acid-base reaction in the NaOH electrolyte, which is atomic efficient and needs no additional acid addition for product separation. Moreover, the weak adsorption of sodium glycolate on the catalyst surface plays a significant role in avoiding excessive oxidation and achieving high selectivity. This work may provide instructions for the electrocatalyst design as well as product separation for the electrocatalytic conversions of alcohols

    Whole genome re-sequencing reveals adaptation prior to the divergence of buffalo subspecies

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    The application of high-throughput genotyping or sequencing data helps us to understand the genomic response to natural and artificial selection. In this study, we scanned the genomes of five indigenous buffalo populations belong to three recognized breeds, adapted to different geographical and agro-ecological zones in Iran, to unravel the extent of genomic diversity and to localize genomic regions and genes underwent past selection. A total of 46 river buffalo whole genomes, from West and East Azerbaijan, Gilan, Mazandaran, and Khuzestan provinces, were resequenced. Our sequencing data reached to a coverage above 99% of the river buffalo reference genome and an average read depth around 9.2× per sample. We identified 20.55 million SNPs, including 63,097 missense, 707 stop-gain, and 159 stop-loss mutations that might have functional consequences. Genomic diversity analyses showed modest structuring among Iranian buffalo populations following frequent gene flow or admixture in the recent past. Evidence of positive selection was investigated using both differentiation (Fst) and fixation (Pi) metrics. Analysis of fixation revealed three genomic regions in all three breeds with aberrant polymorphism contents on BBU2, 20, and 21. Fixation signal on BBU2 overlapped with the OCA2-HERC2 genes, suggestive of adaptation to UV exposure through pigmentation mechanism. Further validation using resequencing data from other five bovine species as well as the Axiom Buffalo Genotyping Array 90K data of river and swamp buffaloes indicated that these fixation signals persisted across river and swamp buffaloes and extended to taurine cattle, implying an ancient evolutionary event occurred before the speciation of buffalo and taurine cattle. These results contributed to our understanding of major genetic switches that took place during the evolution of modern buffaloes

    A Decadal Change in Atmospheric Nitrogen Deposition at a Rural Site in Southern China

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    Elevated atmospheric reactive nitrogen (Nr) emissions and the subsequent nitrogen (N) deposition have negatively impacted the global environment, particularly in China. In order to assess the long-term trends in atmospheric N deposition in the south of China, Taojiang County in Hunan Province was selected as a representative rural area for study. We analyzed interannual variation in atmospheric Nr, including gaseous ammonia (NH3), nitrogen dioxide (NO2), nitrate acid (HNO3) vapor, particulate ammonium (NH4+), and nitrate (NO3−) in air and NH4+-N and NO3−-N in precipitation from 2011 to 2020. The 10-year average atmospheric wet-plus-dry N deposition was 41.9 kg N ha−1 yr−1, which decreased by approximately 24% after 2012, indicating that NH3 and NOx emissions were effectively reduced by emission controls introduced in 2013. Wet deposition accounted for approximately 74% of the total N deposition and was significantly influenced by annual precipitation amount. Reduced N (NH3, pNH4+, and NH4+ in rainwater) was the dominant form, comprising approximately 58% of the total N deposition, while oxidized N (pNO3−, NO2, HNO3, and NO3− in rainwater) accounted for 42% of the total N deposition. Atmospheric HNO3, NO2, and NH3 concentrations and deposition declined by 30–80% over the decade, while particulate NH4+ and NO3− concentrations and deposition remained at relatively stable levels, which suggests that ongoing research and policy should focus on rural particulate pollution. Future strategies must concentrate on the integrated control of NH3 and NOx emissions to mitigate air pollution and protect human health, particularly in rural areas because current abatement efforts are primarily directed toward urban areas and the industrial sector, whereas non-point source NH3 pollution, influenced mainly by agricultural activities, dominates in rural regions
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