Comparative analysis of physiological responses to environmental stress in Hedysarum scoparium and Caragana korshinskii seedlings due to roots exposure.

Hedysarum scoparium and Caragana korshinskii seedlings were used as the test materials to carry out the roots exposure stress model test. By comparing the physiological growth indexes in the leaves of the tested plants, the stress resistance ability was evaluated. The results showed (1) root exposure resulted in excessive oxygen free radicals, which resulted in membrane lipid peroxidation and increased MDA content in two plants. The increase of MDA content in H. scoparium was greater than that in C. korshinskii. (2) H. scoparium mainly regulate their own adaptation to the stress by regulating carotenoids. C. korshinskii adjusts itself to adapt to the stress by regulating chlorophyll. (3) H. scoparium resist this stress mainly by regulating their respiration rate. (4) H. scoparium mainly through the mobilization of proline, by adjusting the proline concentration to reduce their water potential; C. korshinskii reduced its water potential mainly by regulating the concentration of soluble sugar to adapt to the stress. (5) H. scoparium and C. korshinskii activated peroxidase (H. scoparium) and catalase (C. korshinskii) to clean up intracellular peroxides, respectively. To sum up, under the same root exposure ratio, there were significant differences in physiological regulation and morphological indexes between H. and C. korshinskii, but their stress resistance mechanisms were quite different.

Dimethylglyoxime Clathrate as Ligand Derived Nitrogen-Doped Carbon-Supported Nano-Metal Particles as Catalysts for Oxygen Reduction Reaction.

Nitrogen-doped carbon-supported metal nano-particles show great promise as high-performance catalysts for novel energies, organic synthesis, environmental protection, and other fields. The synergistic effect between nitrogen-doped carbon and metal nano-particles enhances the catalytic properties. Thus, how to effectively combine nitrogen-doped carbon with metal nano-particles is a crucial factor for the synthesis of novel catalysts. In this paper, we report on a facile method to prepare nitrogen-doped carbon-supported metal nano-particles by using dimethylgly-oxime as ligand. The nano-particles of Pd, Ni, Cu, and Fe were successfully prepared by the pyrolysis of the corresponding clathrate of ions and dimethylglyoxime. The ligand of dimethylglyoxime is adopted as the source for the nitrogen-doped carbon. The nano-structure of the prepared Pd, Ni, Cu, and Fe particles are confirmed by X-ray diffraction, scanning electron microscopy, and trans-mission electron microscopy tests. The catalytic performances of the obtained metal nano-particles for oxygen reduction reaction (ORR) are investigated by cyclic voltammetry, Tafel, linear sweeping voltammetry, rotating disc electrode, rotating ring disc electrode, and other technologies. Results show that the nitrogen-doped carbon-supported metal nano-particles can be highly efficient catalysts for ORR. The results of the paper exhibit a facile methodology to prepare nitrogen-doped carbon-supported metal nano-particles.