Chiral tetraphenylethylene(TPE) dicycle tetraaldehyde and TPE dicycle tetraacids bearing optically pure groups on the cycles were designed and synthesized. Due to the propeller-like conformation immobilization of TPE ...Chiral tetraphenylethylene(TPE) dicycle tetraaldehyde and TPE dicycle tetraacids bearing optically pure groups on the cycles were designed and synthesized. Due to the propeller-like conformation immobilization of TPE unit, this new class of TPE dicycle was resolved into M-and P-enantiomers, which could emit strong circular polarized luminescence(CPL). Interestingly,these TPE helicates displayed exceptional ability of molecule recognition. While the TPE dicycle tetraaldehyde could detect the microscale water in anhydrous tetrahydrofuran, the chiral TPE dicycle tetraacid could display different fluorescent color after interacting with two enantiomers of a wide variety of chiral amines including monoamines, diamines, and aminols, which could be applied to chiral recognition of these chiral amines. Furthermore, the emission wavelength of TPE dicycle tetraacid was found to change linearly with the enantiomer purity of chiral amine from enantiomer excess(ee) percent-100% to +100%, for the first time showing the potential for quantitative chiral analysis of chiral amines based on emission wavelength change. The emission wavelength was affected less by environmental factors than fluorescence intensity, which would enable the chiral analysis based on wavelength change with higher accuracy and repeatability.展开更多
Greenhouse gas emissions （GHGs） from swine production systems are relatively well researched with the exception of emissions from land application of manure. GttGs inventories are needed for process- based modeling ...Greenhouse gas emissions （GHGs） from swine production systems are relatively well researched with the exception of emissions from land application of manure. GttGs inventories are needed for process- based modeling and science-based regulations. Thus, the objective of this observational study was to measure GHG fluxes from land application of swine manure on a typical corn field. Assessment of GHG emissions from deep injected land-applied swine manure, Phil and reapplication in the spring, on a typical US Midwestern corn-on-corn farm was completed. Static chambers were used Ibr flux measurement along with gas analysis on a GC-FID-ECD＋ Measured gas concentrations were used to estimate GHGs flux using four different models： linear regression, nonlinear regression, first order linear regression and the revised Hutchinson and Mosier （HMR） model, respectively for comparisons.Cumulative flux esmnates after manure apphcatmn of 5.85×10 g·ha^-1（1 ha = 0.01 km） of CO2 6.60×10^1g·ha^-1 of CH4 and3.48 ×10^3g·ha^-1 N2O for the fall trial and 3.11×10^6g·ha^-1 of CO2,2.95×10^3g·ha^-1 of OH4, and 1.47×10^4g·ha^-1 N2O after the spnng reapphcation trial were observed. The N2O net cumulative flux represents 0.595% of nitrogen applied in swine manure for the fall trial.展开更多
基金the National Natural Science Foundation of China (22072050 and 22372066) for financial support。
文摘Chiral tetraphenylethylene(TPE) dicycle tetraaldehyde and TPE dicycle tetraacids bearing optically pure groups on the cycles were designed and synthesized. Due to the propeller-like conformation immobilization of TPE unit, this new class of TPE dicycle was resolved into M-and P-enantiomers, which could emit strong circular polarized luminescence(CPL). Interestingly,these TPE helicates displayed exceptional ability of molecule recognition. While the TPE dicycle tetraaldehyde could detect the microscale water in anhydrous tetrahydrofuran, the chiral TPE dicycle tetraacid could display different fluorescent color after interacting with two enantiomers of a wide variety of chiral amines including monoamines, diamines, and aminols, which could be applied to chiral recognition of these chiral amines. Furthermore, the emission wavelength of TPE dicycle tetraacid was found to change linearly with the enantiomer purity of chiral amine from enantiomer excess(ee) percent-100% to +100%, for the first time showing the potential for quantitative chiral analysis of chiral amines based on emission wavelength change. The emission wavelength was affected less by environmental factors than fluorescence intensity, which would enable the chiral analysis based on wavelength change with higher accuracy and repeatability.
文摘Greenhouse gas emissions （GHGs） from swine production systems are relatively well researched with the exception of emissions from land application of manure. GttGs inventories are needed for process- based modeling and science-based regulations. Thus, the objective of this observational study was to measure GHG fluxes from land application of swine manure on a typical corn field. Assessment of GHG emissions from deep injected land-applied swine manure, Phil and reapplication in the spring, on a typical US Midwestern corn-on-corn farm was completed. Static chambers were used Ibr flux measurement along with gas analysis on a GC-FID-ECD＋ Measured gas concentrations were used to estimate GHGs flux using four different models： linear regression, nonlinear regression, first order linear regression and the revised Hutchinson and Mosier （HMR） model, respectively for comparisons.Cumulative flux esmnates after manure apphcatmn of 5.85×10 g·ha^-1（1 ha = 0.01 km） of CO2 6.60×10^1g·ha^-1 of CH4 and3.48 ×10^3g·ha^-1 N2O for the fall trial and 3.11×10^6g·ha^-1 of CO2,2.95×10^3g·ha^-1 of OH4, and 1.47×10^4g·ha^-1 N2O after the spnng reapphcation trial were observed. The N2O net cumulative flux represents 0.595% of nitrogen applied in swine manure for the fall trial.
