A novel fluorimetric method for determination of laccase activity in organic solvents is proposed, based on the oxidation ofo-phenylenediamine (1,2-diaminobenzene, OPDA) catalyzed by laccase yielding 2,3-diaminophenaz...A novel fluorimetric method for determination of laccase activity in organic solvents is proposed, based on the oxidation ofo-phenylenediamine (1,2-diaminobenzene, OPDA) catalyzed by laccase yielding 2,3-diaminophenazine. The optimal conditions for laccase in organic media areT=55°C, pH=6.5, 1.0×10?2mol/L OPDA, 1.25 mL ethanol, 1.25 mL 1,4-dioxane and 1.25 mL acetone. The linear range of the method proposed in ethanol, 1,4-dioxane and acetone media were 0.44–19.33, 0.11–20.85, 0.38–21.05 U with the detection limit of 0.088, 0.022, 0.076 U, respectively. The proposed method has been applied to the analysis of laccase activity of real samples with more accurate and sensitive than that of the previous method reported.展开更多
The present study applies ＂Textual Patterns＂ like ＂general-specific＂ and ＂claim-counterclaim＂ to explore discourse coherence in Chinese students＇ English writing. The study confirms the function of the textual ...The present study applies ＂Textual Patterns＂ like ＂general-specific＂ and ＂claim-counterclaim＂ to explore discourse coherence in Chinese students＇ English writing. The study confirms the function of the textual patterns as macro-structures for discourse interpretation and production, and proves textual patterns as effective tools in identifying and solving problems with discourse coherence in Chinese EFL （English as a Foreign Language） learners＇ writing.展开更多
文摘A novel fluorimetric method for determination of laccase activity in organic solvents is proposed, based on the oxidation ofo-phenylenediamine (1,2-diaminobenzene, OPDA) catalyzed by laccase yielding 2,3-diaminophenazine. The optimal conditions for laccase in organic media areT=55°C, pH=6.5, 1.0×10?2mol/L OPDA, 1.25 mL ethanol, 1.25 mL 1,4-dioxane and 1.25 mL acetone. The linear range of the method proposed in ethanol, 1,4-dioxane and acetone media were 0.44–19.33, 0.11–20.85, 0.38–21.05 U with the detection limit of 0.088, 0.022, 0.076 U, respectively. The proposed method has been applied to the analysis of laccase activity of real samples with more accurate and sensitive than that of the previous method reported.
文摘The present study applies ＂Textual Patterns＂ like ＂general-specific＂ and ＂claim-counterclaim＂ to explore discourse coherence in Chinese students＇ English writing. The study confirms the function of the textual patterns as macro-structures for discourse interpretation and production, and proves textual patterns as effective tools in identifying and solving problems with discourse coherence in Chinese EFL （English as a Foreign Language） learners＇ writing.
