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Herein, a comprehensive experiment was developed based on the fabrication and characterization of highmolecular- weight silk peptide functionalized graphene nanosheets (SP-Gr) and its application in electrochemical sensing of dopamine. In this experiment, transmission electron microscope, scanning electron microscope, X-ray photoelectron spectroscopy, X-ray diffraction and UV-Vis spectroscopy were used to characterize SP-Gr nanocomposites. SP-Gr nanocomposites were coated onto a glassy carbon electrode surface to fabricate an electrochemical sensor for determining dopamine. Experimental conditions for dopamine determination were optimized. An effective method was developed for determining dopamine. [ABSTRACT FROM AUTHOR]

This paper applied 60 mesh, 80 mesh, 100 mesh quartz sands to make five kinds of sandy soil, utilized laser particle size meter and scanning electron microscope to obtain cumulative percentage of particle size and 135 SEM (scanning electron microscope) images of soil section, used volume fractal formula and PCAS to analyze particle size and SEM images, respectively. Results show that ranges of values about volume fractal dimension of sandy soil are 2. 093 77 ~2. 294 96, 1. 298 7 ~2. 194 25, 2. 014 9 ~2. 280 15 μm, respectively, at 0. 8 to 1 000 micron, 50 to 500 micron, 0. 8 to 50 micron. The pore fractal dimension and porosity of sand are 1.117 9 ~1.133 9 and 0 . 519 4 ~ 0 . 597 2, respectively. The larger the volume fractal dimension is, the better the particle gradation is. Apart from that particle size is the affected factor towards pore fractal dimension, particle size distribution also impacts pore fractal dimension of sandy soil, and the better the particle gradation is, the larger the fractal dimension of pore is. Compared with the particle size of sandy soil, particle gradation is the main factor affecting the porosity of sandy soil. The worse the particle gradation is, the greater the porosity of sandy soil is. [ABSTRACT FROM AUTHOR]

In order to improve the reusable performance of nano-silver in catalytic reduction of p-nitrophenol, polyvinyl alcohol sponge (PVA-S) loaded with nano-silver particles (PVA-S-Ag) was prepared. Scanning electron microscope (SEM), Fourier transform infrared spectra (FT-IR) and X-ray diffraction (XRD) were used to characterize the structure of PVA-S-Ag. The effect of the catalytic reduction of p-nitrophenol by PVA-S-Ag in the presence of sodium borohvdride was investigated by UV-vis. The results show that PVA-S-Ag is an excellent catalyst for the reduction of p-nitrophenol. Resides, PVA-S-Ag still maintains good catalytic reduction effect on 4-NP after several cycles. [ABSTRACT FROM AUTHOR]

Combined with scientific research, a comprehensive chemical experiment of “ Preparation and Characterization of Photo-responsive Supramolecular Gel” was designed. The photo-responsive gel was constructed by two components co-assembly of spiropyran and gelling agent, and its properties were characterized. The results show that the system exhibits good photo-responsive property under light with different wavelengths. The changes in the molecular structure of spiropyran lead to its photochromism, which has good reversibility. The corresponding changes in the UV spectra and scanning electron microscope images have taken place. Through the experiment, students’ interests in scientific research were stimulated, and students’ innovative thinking and comprehensive quality were improved. [ABSTRACT FROM AUTHOR]

A research-oriented experiment on the synthesis, characterization and photo-catalytic property of molybdenum disulfide is designed. In the process of the experiment, sodium molybdate and sulfourea are taken as main materials by adding silicotungstic acid, tetrabutylammonium bromide and oxalic acid as additive. Molybdenum disulfide nanosheet is prepared by hydrothermal method. The students conduct the experiment and us e the scanning electron microscope and X-ray diffraction (XRD) to characterize and analyze the samples independently. The effect of the preparation condition of samples on the catalytic performance is studied. The experiment integrates the knowledge on material synthesis technology, material characterization and catalytic performance test. This experimental mode can effectively help to cultivate students' innovative thinking ability and exploratory spirit [ABSTRACT FROM AUTHOR]