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The grass carp Ctenopharyngodon idella is a commercially relevant carp species with a long-term artificial release history in China. To date, several genetic diversity studies have been performed on the Yangtze River C. idella populations, but similar reports were sparse for the Pearl River populations. Here, our study explored the genetic diversity patterns and population structure of the Pearl River C. idella populations after human intervention using two mitochondrial loci. Phylogenetic analyses demonstrated that grass carp populations in the Pearl River exhibited two maternal genetic lineages. Haplotype networks demonstrated that most main Pearl River haplotypes were shared with those of the Yangtze River samples. No genetic structure was detected among the Pearl populations and low level of population differentiation was observed between individual Yangtze River populations and the Pearl River populations. These findings might be attributed to the high dispersal ability of grass carp, as well as anthropogenic release. Moreover, the nucleotide diversity of the Pearl River populations was higher than that of the Yangtze River, indicating that artificial release programs might have significant effects on the genetic diversity of the Pearl River populations. Taken together, our findings demonstrated artificial release programs may have influenced the Pearl River grass carp populations and provide important knowledge that may guide the future management of grass carp in the Pearl River.

Electrochemical conversion from nitrate to ammonia is a key step in sustainable ammonia production. However, it suffers from low productive efficiency or high energy consumption due to a lack of desired electrocatalysts. Here we report nickel cobalt phosphide (NiCoP) catalysts for nitrate‐to‐ammonia electrocatalysis that display a record‐high catalytic current density of −702±7 mA cm−2, ammonia production rate of 5415±26 mmol gcat−1 h−1 and Faraday efficiency of 99.7±0.2 % at −0.3 V vs. RHE, affording the estimated energy consumption as low as 22.7 kWh kgammonia−1. Theoretical and experimental results reveal that these catalysts benefit from hydrogen poisoning effects, which leave behind catalytically inert adsorbed hydrogen species (HI*) at Co‐hollow sites and thereupon enable ideally reactive HII* at secondary Co−P sites. The dimerization between HI* and HII* for H2 evolution is blocked due to the catalytic inertia of HI* thereby the HII* drives nitrate hydrogenation timely. With these catalysts, the continuous ammonia production is further shown in an electrolyser with a real energy consumption of 18.9 kWh kgammonia−1. [ABSTRACT FROM AUTHOR]

Hydrogen spillover in metal‐supported catalysts can largely enhance electrocatalytic hydrogenation performance and reduce energy consumption. However, its fundamental mechanism, especially at the metal–metal interface, remains further explored, impeding relevant catalyst design. Here, we theoretically profile that a large free energy difference in hydrogen adsorption on two different metals (|ΔGH‐metal(i)−ΔGH‐metal(ii)|) induces a high kinetic barrier to hydrogen spillover between the metals. Minimizing the difference in their d‐band centers (Δϵd) should reduce |ΔGH‐metal(i)−ΔGH‐metal(ii)|, lowering the kinetic barrier to hydrogen spillover for improved electrocatalytic hydrogenation. We demonstrated this concept using copper‐supported ruthenium–platinum alloys with the smallest Δϵd, which delivered record high electrocatalytic nitrate hydrogenation performance, with ammonia production rate of 3.45±0.12 mmol h−1 cm−2 and Faraday efficiency of 99.8±0.2 %, at low energy consumption of 21.4 kWh kgamm−1. Using these catalysts, we further achieve continuous ammonia and formic acid production with a record high‐profit space. [ABSTRACT FROM AUTHOR]

The fish gut microbiome is well known for its role in degrading nutrients to improve the host's digestion and absorption efficiency. In this study, we focused on the core physiological adaptability during the various reproductive stages of the black Amur bream (Megalobrama terminalis) to explore the interaction mechanisms among the fish host gut mucosal structure, gut enzyme activity, and gut microbial metabolism in the course of the host's reproductive cycle. Our findings showed that M. terminalis exhibited locomotion metabolic type (aids in sporting) in the reproductive stage, and a change to visceral metabolic type (aids in digestion) during non-reproductive and post-reproductive stage phases. The impact of metabolic type selection and energy demand during various reproductive stages on fish nutrition strategy and digestive function was substantial. Our resulted showed that mitochondria in intestinal epithelial cells of reproductive M. terminalis appeared autophagy phenomenon, and the digestive enzyme activities in the intestines of reproductive M. terminalis were lower than those in the non-reproductive and post-reproductive individuals. Moreover, these differences in nutrition strategy have a prominent impact on the gut microbiome of reproductive M. terminalis, compared to non-reproductive and post-reproductive samples. Our findings showed that reproductive females had lower levels of alpha diversity compared to non-reproductive and post-reproductive females. Our results also showed a greater functional variety and an increase in functional genes related to carbohydrate, lipid, amino acid, cofactors, and vitamin metabolic pathways in the NRS and PRS group. It is noteworthy that an enrichment of genes encoding putative enzymes implicated in the metabolism of taurine and hypotaurine was observed in the RS samples. Our findings illustrated that the stability and resilience of the gut bacterial community could be shaped in the wild fish host–microbiome interactions during reproductive life history. [ABSTRACT FROM AUTHOR]

In this study, phosphogypsum (PG) is simulated by doping fluorine and phosphorus ions in an analytically pure reagent of gypsum dihydrate. The influence of fluorine and phosphorus impurity and content on the dehydration reaction process of phosphogypsum and its crystalline micromorphology is assessed during the preparation of α‐type gypsum hemihydrate in the reversed‐phase microemulsion system and its mechanism. The results show that when the fluorine content increases from 0 to 1.0 mol L−1 (ωNaF = 1.0 mol L−1), the dehydration process of dihydrate gypsum will be greatly slowed down. Scanning electron microscopy (SEM) analysis showed that even a small amount of F− (ωNaF = 0.2 mol L−1) can significantly inhibit the formation of α‐type hemi‐hydrated gypsum. When ωH3PO4 = 0.10 mol L−1, the water of crystallization content in the solid phase of the sample decreased to 5.24% after 90 min, which is significantly lower than during the same period of the benchmark group. However, there is a threshold value for the effect of phosphorus on the microscopic morphology of the α‐type gypsum hemihydrate crystals, when ωH3PO4 ≤ 0.04 mol L−1, the crystal morphology is basically unaffected. Moreover, when ωH3PO4 continued to increase, the defects on the crystal surface increased. [ABSTRACT FROM AUTHOR]