Search

Global biodiversity loss has generated great interest in the role of plant communities in driving ecosystem functions. There is limited understanding of how soil properties, plant richness and plant community composition interact to affect ecosystem multifunctionality.We conducted a constructed ecosystem experiment by simultaneously manipulating soil origin (i.e. fertile farmland soil and relatively infertile bare land soil), plant richness and community composition (one‐species monoculture, and all possible two‐, three‐ and four‐species combinations of five plants) to evaluate their influence on ecosystem multifunctionality related to the accumulation of biomass, carbon (C) and nitrogen (N) in plants, greenhouse gas emissions, soil nutrients, soil N fixation and mineralization of N and phosphorus (P).We found that ecosystem multifunctionality was significantly affected by soil origin, plant community composition and the community‐weighted mean (CWM) of plant biomass, but not by plant richness.We grouped the community composition into the N‐fixing group (including N‐fixing plants) and the non‐N‐fixing group (excluding N‐fixing plants). The N‐fixing plant group exhibited significantly higher multifunctionality than the non‐N‐fixing species group in both soil origins. For bare land soil, multifunctionality increased with the increasing relative abundance and biomass ratio of Albizia julibrissin (N‐fixing species) in communities, but decreased with the biomass ratio of Platycladus orientalis (non‐N‐fixing species). For farmland soil, multifunctionality increased with the abundance of Toona sinensis (non‐N‐fixing species) and the biomass ratio of Albizia julibrissin, but decreased with the abundance and biomass ratio of Morus alba (non‐N‐fixing species). These results indicate that the key species determining ecosystem multifunctionality vary under different soil conditions.Synthesis and applications: We propose that plant community composition and the relative abundance and biomass ratio of key species drive ecosystem multifunctionality. We suggest that selecting the appropriate plant combination under different soil conditions should be emphasized in ecological restoration projects. Our study highlights the differentiated roles of key species on ecosystem functions under different resource conditions. The N fixation in general plays a crucial role in driving ecosystem multifunctionality and the N‐fixing plants can serve as restoration tools in nutrient‐poor degraded lands. [ABSTRACT FROM AUTHOR]

Water–sand mixture inrush generally poses a significant threat to the safe operation of the quarry of coal mines. Therefore, proactive management initiatives are essential to enhance the impact resulting from mining operations. A novel approach involving grouting into the unconsolidated sand aquifer and the weathered zone was initially executed in the 1010-1 panel of the Wugou coal mine in Anhui Province, China. Considering the hydrogeological conditions of the study area, over 70 thousand tons of cement and fly ash were injected through 42 boreholes. Sampling, laboratory tests, similar materials model simulations, and numerical simulations of the trending and dipping profiles were all employed to elucidate the evolution and characteristics during the progression of the No. 10 coal seam. The outcomes illustrated that the grouting execution had transformed the structure of the porous media, weakened the watery media, and intensified the mechanical strength of the No. 4 aquifer and the weathering zone. This transformation proved beneficial in reducing the heights of the caving zone and water-conductive fracture zone, leaving more coal–rock pillars for safety. Twenty-seven underground detection drill holes and whole-space 3D resistivity exploration were adopted to verify its transformed property of low water content. During the mining process, the height of the caving zone at 19.70 m was measured through inter-hole parallel electrical detection. The pressure of hydraulic supports in the grouted area did not exceed the rated working pressure during mining. All of these findings highlight the significant impact of grouting in this study area. The successive safe mining of the 1010-1 panel demonstrates that grouting can be used to prevent water–sand mixture inrush during mining operations. [ABSTRACT FROM AUTHOR]

The alkylation of toluene catalyzed by modified HZSM-5 was an economical and efficient way to produce para-xylene (PX) due to the full utilization of toluene and fewer by-products. It has attracted significant attention in optimizing the modification method for both high activity and PX selectivity. In this study, we employed SiO2 and MgO to co-modify HZSM-5 for the alkylation of toluene with dimethyl carbonate. The catalysts in which SiO2 was deposited first with trimethoxysilane (TMOS) as the precursor, showed significantly higher activity and PX selectivity than that of depositing MgO first. When the content of SiO2 and MgO was both 5%, the conversion of toluene was 12%, with the selectivity of PX up to 85% (400 °C) for the 5Si-5Mg/ZSM-5 catalyst (depositing SiO2 first). However, the conversion and selectivity were only 5% and 56% for the 5Mg-5Si/ZSM-5 catalyst (depositing MgO first). The analysis of structure and acid properties indicated that the pre-deposition of SiO2 can regulate the location of MgO, leading to the suppression of the external acid sites and the inhibition of the pore blockage by MgO. Owing to the pore size of ZSM-5 being slightly smaller than the molecular size of TMOS, TMOS molecules would be embedded in the pore entrance, making SiO2 tend to prevent MgO from entering the micropore of ZSM-5. [ABSTRACT FROM AUTHOR]

In the investigation of stratigraphic reservoirs, a significant discrepancy frequently exists between the delineation of the formation pinch-out line as traced using the characteristics of seismic wave reflections and the actual location of the formation pinch-out line. This has been the main problem restricting further hydrocarbon exploration and development. In this study, Hala'alate Mountain on the northwestern margin of the Junggar Basin is taken as an example for carrying out the study of stratigraphic reservoirs by integrating logging, drilling, and 3D seismic data. On the one hand, in studies based on the identification of formation pinch-out points using seismic data, the identification error of reservoir pinch-out lines is reduced by the improved included angle extrapolation method by utilizing the half energy attribute. On the other hand, the Poisson's ratio curve is reconstructed using acoustic curves and oil-gas sensitive logging, then the reservoir oil-bearing facies zone is predicted using Poisson's ratio post-stack genetic inversion to comprehensively analyze the controlling factors of stratigraphic reservoirs. The study area mainly features structural lithologic reservoirs, structural stratigraphic reservoirs and stratigraphic overlaps that pinch out reservoirs. The boundary of a stratigraphic reservoir is affected by the dip angle of the unconformity surface, the formation dip angle, and other factors. The improved included angle extrapolation method improves the identification accuracy of stratigraphic overlap pinch-out reservoirs. The reservoir distribution then is calculated according to Poisson's ratio inversion, improving the prediction accuracy for the reservoir. This method improves the predictive effect for stratigraphic reservoirs and provides a new idea for the exploration and development of similar reservoirs. [ABSTRACT FROM AUTHOR]

Carbon (C) allocation plays an important role in plant adaptation to water and nutrient stresses. However, the effects of drought and nutrient deficiencies on the allocation of recently fixed C in the plant–soil–microbe system remain largely unknown. Herein, we studied the response of C allocation of Sophora moorcroftiana (an indigenous pioneer shrub in Tibet) to drought, nitrogen (N) deficiency and phosphorus (P) deficiency using a microcosm experiment. The 13CO2 continuous labeling was used to trace C allocation in the plant–soil–microbe system. We found that drought significantly reduced plant 13C, but it increased 13C accumulation in soil. The decreased plant 13C under drought was attributed to the decrease of 13C in stem and root rather than that in leaf. The excess 13C fraction in the microbial biomass (MB13C) was reduced by N deficiency, but it was not affected by the combination of drought and N deficiency, indicating that drought weakened the effects of N deficiency on MB13C. By contrast, MB13C increased under the combination of drought and P deficiency, suggesting that drought enhanced the effects of P deficiency on MB13C. Drought and nutrient deficiencies regulated the belowground 13C allocation. Specifically, drought and P deficiency increased the allocation of 13C to root and N deficiency regulated the allocation of 13C to microbial biomass C and dissolved organic C in soil. Notably, soil 13C decreased with increasing plant 13C, while MB13C first decreased and then increased with increasing plant 13C. Overall, our study demonstrated that drought and nutrient deficiencies interactively affected C allocation in a plant–soil–microbe system and provided insights into C allocation strategies in response to multiple resource (water and nutrient) stresses under environmental changes. [ABSTRACT FROM AUTHOR]

To date, four species of porcine circoviruses (PCVs), including PCV1‐4, have been reported to exist in the clinical cases. Fast and effective differential detection is critical to monitor the infection and co‐infection status of PCVs for adopting reliable control strategies. However, currently available methods cannot simultaneously differentiate the four species of PCV strains. In this study, a quadruplex real‐time PCR assay based on TaqMan probes was developed for differential detection of PCV1‐4. The new quadruplex real‐time PCR assay exhibited satisfied specificity, sensitivity, repeatability and reproducibility. In addition, the new assay was applied to the detection of 120 clinical samples collected from 2016 to 2020 in Jiangsu province of China and compared with previously reported PCV1‐4 singleplex conventional PCR assays. Based on the clinical performance, the results from the quadruplex real‐time PCR and conventional PCR assays showed 100% agreement. A total of 47 samples were detected as PCV positive by the quadruplex real‐time PCR assay, including 1, 2, 1 samples were co‐infected with PCV1 and PCV4, PCV2 and PCV3, PCV2 and PCV4, respectively. Full‐length ORF2 sequencing and phylogenetic analysis supported the real‐time PCR results that 5, 34, 8 and 4 of the 51 PCV sequences were PCV1, PCV2, PCV3 and PCV4, respectively. This study provides a promising alternative tool for rapid differential detection of PCVs and confirms the coexistence of all species of PCV1‐4 strains in Jiangsu province in recent years. [ABSTRACT FROM AUTHOR]