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The utilization of lignin remains a great challenge due to its complex non-repetitive structure and the lack of efficient catalyst. Herein, a single-atom catalyst Ni@N-C was designed via a facile chelation-anchored strategy. Ni atoms were immobilized on the N-doped carbon carrier by a two-stage pyrolysis of a mixture of D-glucosamine hydrochloride, nickel acetate and melamine. D-glucosamine hydrochloride as a chelating agent prevented the aggregation of Ni2+, and melamine provided enough N to anchor Ni by forming Ni-N4 structure. Ni@N-C gave a 31.2% yield of aromatic compounds from lignin hydrogenolysis, which was twice higher than that achieved by Ni cluster catalyst. Based on the experimental and DFT calculation results, the higher activity of Ni@N-C was attributed to its lower H2 dissociation energy and the reduced energy barriers of the transition states. The strategy described opens an efficient green avenue for preparing single-atom catalyst that possesses outstanding activity in lignin depolymerization.

There is increasing evidence from molecular studies to support the role of inflammation and increased oxidative stress that produce structural and electrical atrial remodeling to produce Atrial Fbrillation (AF). Oxidative damage to cardiomyocytes yields chemical substances that are secreted in urine. These substances can serve as biomarkers that can be measured, potentially allowing clinicians to quantify oxidative damage to the heart.

According to the requirements of the fiber optic gyro with high-accuracy, the high-power and high-accuracy double-pass backward (DPB) erbium-doped fiber source was used. The optimization parameters of high-power, high-efficiency erbium-doped superfluorescent fiber source are designed. Near Gaussian-shaped spectrum of erbium-doped superfluorescent fiber source was designed. Near Gaussian-shaped spectrum of erbium-doped superfluorescent fiber source in single peak aside the constraints of double peak, single peak of fiber source more effective control of the temperature sensitivity and stability that mean wavelength. The ASE light source mathematical mode was established by the theoretical analysi, and of erbium-doped fiber was determined by the spectral shape analyzed the parameters of erbium-doped fiber and pump laser in the experiment. Then to erbium-doped fiber and a pump laser temperature characteristics and compensation for the research priorities of theoretical analysis, the length and the doping concentration of erbium-doped fiber and pump power and erbium-doped fiber matching test, finally the pump power is 170 mW at 974.6 nm, excellent performance has been obtained which power of the light source is 20 mW with 9.6 m erbium-doped fiber. The near Gaussian-shaped spectrum of erbium-doped superfluorescent fiber source with 0.5 ppm/°C mean wavelength stability was obtained, repeatability of the set point temperature better than 2 ppm.

The ultra-large, single-crystal Ag nanosheets and their assembled films can be easily one-pot prepared at room temperature via a chloroform-water interfacial reaction route with o-ethoxyaniline (OEA) in chloroform as reductant and AgNO3 in water as precursor. The as-obtained single-crystal Ag nanosheets can reach as large as 16 μm in side length and as thin as 22 nm in thickness. The results show that reagent concentrations, temperature and organic phase in current liquid-liquid reaction have significant influences on the formation of Ag sheet-like nanostructures. The possible mechanism was proposed for the growth and formation of Ag nanosheets and their assembled films. Furthermore, using p-aminothiophenol (PATP) as a model molecular probe, the Ag nanosheet-assembled films exhibit outstanding surface-enhanced Raman scattering (SERS) response and high reproducibility.