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The notion of teacher identity has gained momentum in second language (L2) teacher education in the past decade. However, the research into Chinese as a Foreign Language (CFL) teacher identity has yet to receive more attention. The study employed a narrative inquiry to explore a native Chinese CFL in-service teacher’s identity negotiation and transformation within an international teacher education program. Self-reported narrative accounts, including multiple in-depth interviews and once-a-term reflective journals, were complemented by field notes and program documents. This data captured how the participant teacher negotiated internally with self and externally with the new environment to pursue professional growth. Mezirow’s transformative learning theory was used to reveal the cognitive trajectory of the participant’s teacher identity transformation with critical reflection as the central stage. Further, guided by Eteläpelto et al.’s framework of professional agency, the study also unraveled multiple external and internal influences on the transformational trajectory. The findings confirmed the value of integrating these two theoretical perspectives to explore language teacher identity development and offer insights into L2 teacher education practices focusing on teacher identity development.

A highly sensitive and selective electrochemical sensor modified with poly-(L-cysteine)/CuO nanoneedles/N-doped reduced graphene oxide (L-Cys/NN-CuO/N-rGO) has been prepared for the testing of trace Pb2+. The electrochemical performance of this proposed sensor was investigated using electrochemical impedance spectroscopy (EIS). Based on the excellent electrochemical properties of NN-CuO/N-rGO as well as the specific complexation of natural substance L-cysteine with Pb2+, the L-Cys/NN-CuO/N-rGO was applied as a voltammetric biosensor for the determination of trace Pb2+ at pH 5.0. Under the optimum experimental conditions, the voltammetric peak current was linear with the Pb2+ concentration over the range from 0.001 to 5.0 nM and 5.0 to 1000 nM, respectively, with a low detection limit for Pb2+ concentration on the biosensor of 8.0 × 10−5 nM (S/N = 3). The significant sensitivity, selectivity, and electron conductivity of this L-Cys/NN-CuO/N-rGO modified electrode have also been studied. The specific detection of Pb2+ in water samples was also carried out.

A zeolitic imidazolate framework-8 (ZIF-8)/reduced graphene oxide (rGO) nanocomposite was formed by using an efficient synthetic method. The morphology and structure of the ZIF-8/rGO nanocomposite were characterized by scanning electron spectroscopy (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) mapping. The ZIF-8/rGO nanocomposites were immobilized on a carbon paste electrode (CPE) to construct a high-performance nonenzymatic electrochemical H2O2 sensor. A cyclic voltammetry (CV) study showed that the ZIF-8/rGO nanocomposites displayed better electrocatalytic activity toward H2O2 reduction compared to that of ZIF-8. An amperometric study indicated that the H2O2 sensor displayed high performance, which offered a low detection limit (0.05 μM) (S/N = 3), a high sensitivity (4.01 μA mM−1 cm−2), and a wide linear range (from 1.0 to 625 μM). An electrochemical reaction mechanism was proposed for H2O2 reduction on the ZIF-8/rGO/CPE. Importantly, the as-fabricated H2O2 sensor exhibited good reproducibility and excellent selectivity. Furthermore, the constructed high-performance sensor was utilized to monitor the H2O2 levels in real samples, and satisfactory results were obtained. These results demonstrated that the ZIF-8/rGO nanocomposite can be used as a good electrochemical sensor material in practical applications.

Many endophytic bacterial strains are now successfully used for plant-growth promotion (PGP) and as biocontrol agents (BCA) against plant diseases. This is a promising strategy for the improvement of crop productivity, thereby reducing the use of chemical pesticides and fertilizers. The objectives of this study were to isolate endophytic bacteria from the medicinal plant Dendrobium candidum Wall ex Lindl in China, and evaluate the biological control and PGP characteristics of these bacteria. Antagonistic tests were performed against fungal pathogens. Twenty-two of the 83 bacterial isolates showed antagonistic activities. These antagonistic isolates were screened in vitro for PGP traits, such as the production of indoleacetic acid (IAA), siderophores, proteases, and phosphate solubilization. Based on the tested PGP traits, strain YW was selected for further study. Strain YW was identified as Pseudomonas saponiphila based on its 16S rRNA and gyrB gene sequences. We detected the antifungal metabolite-encoding genes phlD, and hcnBC genes encoding 2,4-diacetylphloroglucinol (2,4-DAPG) and hydrogen cyanide (HCN) from strain YW. We measured the effect of strain YW on the growth of pepper seedlings under greenhouse conditions. Our results showed that its antifungal potential may be attributed to 2,4-DAPG and HCN antibiotics, as well as protease and siderophore production, and growth promotion may be related to the ability of isolate YW to synthesize IAA and solubilize phosphate. The PGP and antifungal activities of strain YW suggest that it may be exploited as a potential bioinoculant agent. This is the first report of a P. saponiphila strain with PGP attributes.