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Microcrystalline cellulose-supported manganese dioxide hydrogels (MCC@MnO2/SA) were prepared by chemical deposition and used to adsorb U(VI) in water. The hydrogels were characterized by SEM-EDS, FTIR and XPS, and the adsorption effect of MCC@MnO2/SA on U(VI) under different factors (pH, contact time, temperature, initial concentration of U(VI)) was investigated. The results showed that when the initial concentration of U (VI) was 10 mg/L, the pH value was 4 and the temperature was 303 K, the maximum adsorption capacity of U (VI) by MCC@MnO2/SA reached 234. 11 mg/g, which was about 11% higher than that before modification. The adsorption process conforms to the quasi-secondary kinetics, and its isothermal adsorption model is more suitable for Langmuir, mainly monolayer chemical adsorption, its adsorption is a spontaneous endothermic process. The main adsorption mechanism is chemical adsorption and valence forces generated by the combination of covalent metal ions and surface electrons, and MnO2 provides more functional groups. The removal rate of the hydrogel remained above 78% after 5 cycles, which was recyclable. [ABSTRACT FROM AUTHOR]

To comprehensively understand the effect of selenium(Se)supplementation on Codonopsis pilosula, effects of sodium selenite levels on Se accumulation, growth, physiology and quality were explored by using hydroponic experiments. The results were as follows:(1)Treatment with 0.2 mg·L-1 Se promoted leaf size, plant height and biomass of C. pilosula, while treatment with 10 mg·L-1 Se suppressed them.(2)Both increasing Se level and exposure time to C. pilosula seedlings could raise its Se contents in root and leaf, and Se was distributed in organs with an order of root>leaf>stem.(3)Treatment with 0.2 mg·L-1 Se increased photosynthetic pigment content and root activity, and reduced malondialdehyde, proline and hydrogen peroxide contents, while treatment with 10 mg·L-1 Se had opposite effects.(4)Treatment with 0.2 mg·L-1 Se had positive effects on accumulations of lobetyolin, polysaccharide, and soluble protein, while treatment with 10 mg·L-1 Se had negative effects on the accumulations of polysaccharide and soluble protein. In summary, sodium selenite has double effect on C. pilosula; application of appropriate Se is beneficial to its growth, plant physiology and quality, and 0.2 mg·L-1 Se level is the optimum. This study may improve us to understand the effect of selenite level on the biology effect of C. pilosula, which will be useful for the basic research and cultivation of Se-enriched C. pilosula. [ABSTRACT FROM AUTHOR]

There are difficulties in the transmission electron microscope (TEM) sample preparation of SiC particles reinforced Al-based composite (SiC /Al) due to the complexity of phase constitute, since it needs positional sampling and large range of observation for studying the nexus between SiC and other constituted phases. In the present work, focused ion beam( FIB)with external picking up was chosen in making simple for TEM. The samples are made into sheet with large area in the vacuum chamber and removed and placed on an attached membrane net outside the vacuum chamber. A plurality of regions can be observed in single sample injection, due to there are multi-chip samples on an attached membrane net. The method was thus proven to be applicable to study the structure of SiC /Al by TEM. The mother can be used in other materials for high-efficiency and low-cow. [ABSTRACT FROM AUTHOR]