Synergistic effect of size-dependent PtZn nanoparticles and zinc single-atom sites for electrochemical ozone production in neutral media

Electrochemical ozone production(EOP) via water electrolysis represents an attractive method for the generation of high-purity O3. Herein, the X-PtZn/Zn-N-C electrocatalysts show a strong structural sensitive behavior depends on the size of the PtZn nanoparticles and their EOP activity exhibits a volcano-type dependence for the O3 performance in neutral media. The 7.7-PtZn/Zn-N-C exhibits EOP current efficiency of 4.2%, and shows the prominent performance in the production of gaseous O3 with a value of 1647 ppb at 30 min, which is almost 4-fold compared to 2.2-Pt Zn/Zn-N-C. Based on the experiments and theoretical calculations, the performance of the EOP process was determined by the nanoparticle size-effect and the synergistic effect between the PtZn nanoparticles and atomically dispersed Zn-N-C. Furthermore, the fivemembered cyclic structure of O3 can be stabilized between the PtZn nanoparticle and the Zn-N-C support,indicating that O3 is produced at the interface.

Genetic variation in GmCRP contributes to nodulation in soybean(Glycine max Merr.)

Symbiosis between soybean and rhizobia contributes to soybean yield and quality. Although secreted rhizobial type Ⅲ effectors are known to regulate infection and promote nitrogen fixation, much about them remains unknown. Mutation of NopC, a type Ⅲ effector from Sinorhizobium fredii HH103, reduced nodule numbers and dry weights in 310 soybean accessions, and expression of NopC in soybean hairy roots promoted symbiosis. Based on observed differences in nodule traits between Suinong 14 and Zyd 00,006inoculated with HH103 and the NopC mutant, 11 QTL associated with rhizobia were identified in chromosome segment substitution lines(CSSLs) derived from Suinong 14 and Zyd 00006. Using chromosome fragment insertion, whole-genome sequencing of Suinong 14 and Zyd 00006, and qRT-PCR,Glyma.19G176300(GmCRP) was identified as a candidate gene associated with NopC, and GmCRP was found to be induced by NopC to positively regulate nodulation. SNPs located in the regulatory regions of GmCRP influenced its expression response to NopC, with SNPs contributing to nodulation having been selected during domestication. Our findings reveal the function of a soybean gene encoding a rhizobial type Ⅲ effector that contributes to symbiosis, and will facilitate the practical application of symbiotic nitrogen fixation in molecular breeding.

Laser mass spectrometry for high sensitive and multi-component analysis of exhaust gas from vehicles

Laser mass spectrometry is a newly developed method for pollutant detection. It combines resonance-enhanced multiphoton ionization (REMPI) and time-of-flight mass spectro- metry (TOF-MS). It may detect pollutants with high sensitivity, high selectivity and in a multi-component way. In this note, laser mass spectrometry was used to detect the pollutants in exhaust gases from vehicles. With one-color REMPI (at 266 nm), several aromatic hydrocarbons, including benzene, toluene, xylene, C3-benzene, etc., were detected. These substances were selectively ionized by (1+1) REMPI and their mass resolution was detected by a TOF mass spectrometer. And a quantitative analysis was achieved.