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NiCoAl layered double hydroxide nanosheets (NiCoAl-LDHNs) were prepared by a one-step solvothermal method. The shape and size of the obtained nanosheets are optimized by adjusting the solvothermal time and the molar concentration ratio of Ni2+/Co2+ to obtain the electrode material with the best performance. When the solvothermal time is 9 h and the molar concentration ratio of Ni2+/Co2+ is 1:1, NiCoAl-LDHNs has the best morphology and electrochemical performance. When assembled into a supercapacitor, NiCoAl-LDHN-9 has a high specific capacitance of 1228.5 F g−1 at 1 A g−1. As the current density is increased to 20 A g−1, the specific capacitance is 1001.8 F g−1, which still has a high capacitance retention of 81.6%. When NiCoAl-LDHN-9 was assembled into an asymmetric supercapacitor, NiCoAl-LDHN-9//AC has a specific capacitance of 102.1 F g−1 at 0.5 A g−1. The asymmetric supercapacitor devices also show excellent electrochemical performance in terms of energy density (35.9 Wh kg−1 at 225.8 W kg−1), power density (4.8 kW kg−1 at 22.2 Wh kg−1) and cycle life (capacitance retention rate after 10,000 cycles is 87.1%). Those results indicate that NiCoAl-LDHN have the potential to be promising electrode materials for high performance supercapacitors.

A compact evanescent wave detection platform (EWDP) is developed for the detection of fluorescence gold nanoclusters. The EWDP employs a simple optical system and a Si-based photodetector SOP-1000 assembly to improve the optical efficiency and detection sensitivity. A microfluidic sample cell is also used to decrease the amount of analyte to 200 μL (The volume of sample cell is really about 30 μL). On this basis, we design a strategy for detecting dopamine (DA) based on the photoinduced electron transfer (PET) quenching mechanism. By introduction of tyrosinase (TYR) during the detection, the testing time is shortened to 1 min. The fluorescence emission signal decreased dramatically and the quenching ratio (F0–F)/F0 is linearly related to the concentration of DA in the range of 0.03–60 μM with a detection limit of 0.03 μM. Additionally, this detection platform has potential applications for DA fast detection in the microsamples.

We have prepared nitrogen and oxygen enriched hierarchically porous carbon (NOHPC) based on a concept of neutralization reaction. The reactant of KOH and the reaction product of KCl mixed in soybean flour acts as chemical activators and porogens during carbonization, which play different roles to produce the hierarchical porous structure containing macropores, mesopores and micropores. After the investigation of the effect of the reaction pH and carbonization temperature on the structure, the optimized NOHPC with reaction pH at 11.5 and carbonization temperature at 900 °C has a large area (2404.3 m2 g−1), with a high pore volume of 1.31 cm3 g−1, a nitrogen content (0.42%) and an oxygen content (32.1%). When assembling supercapacitors, NOHPC has a extremely large specific capacitance (381 F g−1 at 1 A g−1) and large energy density (20.78–15.42 Wh kg−1), and possesses good rate performance. Particularly, the symmetric supercapacitor assembled based on NOHPC-900-11.5 has a good cycle stability in the voltage range of 0–1.8 V in a two-electrode system with 1 M Na2SO4 as the electrolyte. It is worth noting that when Tetraethylazanium tetrafluoroborate (TEATFB) in propylene carbonate and 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide (EMIMNTF2) are selected as electrolyte, high energy densities of 31.4 Wh kg−1 and 71.6 Wh kg−1 are achieved. The above results indicate that NOHPC prepared based on neutralization reaction is superior energy storage materials. This work has universal significance in producing high performance porous carbons from biomass.

Traditional Chinese Medicine (TCM) is becoming much more international and widely accepted. More and more foreign students come to mainland China to study this great yet mysterious discipline. However, the current teaching methods are far from satisfaction. This paper analyzes some existing problems and contradictions present in the teaching practices and suggests some measures for improvement.