Publications by authors named "Junjian Xu"

l-Theanine, as an active component of the leaves of the tea plant, possesses many health benefits and broad applications. Chemical synthesis of l-theanine is possible; however, this method generates chiral compounds and needs further isolation of the pure l-isoform. Heterologous biosynthesis is an alternative strategy, but one main limitation is the toxicity of the substrate ethylamine on microbial host cells.

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As potent allelochemicals, phenolic acids are believed to be associated with replanting disease and cause microflora shift and structural disorder in the rhizosphere soil of continuously monocultured . The transcriptome sequencing was used to reveal the mechanisms underlying the differential response of pathogenic bacterium and beneficial bacterium on their interactions with phenolic acids, the main allelochemicals in root exudates of in the monoculture system. The microbes were inoculated in the pots containing soil and the medicinal plant in this study.

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The pi-pi interaction between pyrene molecules and single-walled carbon nanotubes (SWNTs) or multi-walled carbon nanotubes (MWNTs) was studied by fluorescence, FTIR, Raman spectroscopy and molecular simulation. The carbon nanotubes were incubated in pyrene solution and dried for characterization. A broadband fluorescence emission at 463 nm of the incubated samples was observed, which is similar to that of pyrene excimers but shifts to shorter wavelength.

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The preferential growth of single-walled carbon nanotubes (SWNTs) on silica spheres with various diameters was realized for the first time by chemical vapor deposition (CVD) of methane. SWNTs tend to wrap the silica spheres to form a new superstructure of uniform SWNT nanoclaws when the diameters of the silica spheres are larger than 400 nm. The SWNTs obtained on silica spheres have highly graphitic tubular walls as characterized by Raman spectroscopy and HRTEM.

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