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Arbuscular mycorrhizal (AM) fungi play key roles in plant nutrition and plant productivity. AM fungal responses to either plant identity or fertilization have been investigated. However, the interactive effects of different plant species and fertilizer types on these symbiotic fungi remain poorly understood. We evaluated the effects of the factorial combinations of plant identity (grasses Avena sativa and Elymus nutans and legume Vicia sativa) and fertilization (urea and sheep manure) on AM fungi following 2-year monocultures in a sown pasture field study. AM fungal extraradical hyphal density was significantly higher in E. nutans than that in A. sativa and V. sativa in the unfertilized control and was significantly increased by urea and manure in A. sativa and by manure only in E. nutans, but not by either fertilizers in V. sativa. AM fungal spore density was not significantly affected by plant identity or fertilization. Forty-eight operational taxonomic units (OTUs) of AM fungi were obtained through 454 pyrosequencing of 18S rDNA. The OTU richness and Shannon diversity index of AM fungi were significantly higher in E. nutans than those in V. sativa and/or A. sativa, but not significantly affected by any fertilizer in all of the three plant species. AM fungal community composition was significantly structured directly by plant identity only and indirectly by both urea addition and plant identity through soil total nitrogen content. Our findings highlight that plant identity has stronger influence than fertilization on belowground AM fungal community in this converted pastureland from an alpine meadow.

The world's largest alpine pastures are found on the Tibetan Plateau, where considerable climate changes and human impacts have been experienced. Identifying their contributions to terrestrial productivity is essential if we are to adapt to, or mitigate the effects of, climate change. In this work, we begin by showing how the current warming and wetting of the climate over the last three decades has favored plant growth, as consistently captured by satellite observations and 15 models. However, the interactions between climate factors explain less of the variation in greenness observed by satellites after the 2000s, implying non-climatic influences. Next, we show that there is a significant negative impact of livestock grazing on pasture greenness, especially in peak summer. Official statistics across 72 counties verify these negative impacts, especially in poorer pastures with a higher density of grazing livestock. The variation in grazing density has a stronger negative effect on vegetation growth during the early part of the growing season after the 2000s, as compared with that before the 2000s. We found a compensatory effect of grazing and climate on alpine grassland growth, and the grazing regulates the response of vegetation greenness to climate change by modulating the dependency of vegetation growth on temperature. Thus, we suggest there is a weakening influence of climate on the greenness of alpine pastures, largely due to a strengthening influence of management, which should be considered by both the scientific community and policymakers.

Abstract Comprehensive information about the concentrations, distribution, and modes of occurrence of elements in coal are important from the environmental and economic point of view. Although a great number of previous studies have investigated the geology of coalbed methane in the Qinshui Basin, only a few studies focused on the inorganic constituents in coal. More specifically, the mode of occurrences of valuable element Li in the No. 3 Coal is still unclear, although Li was found enriched. In this study, we present mineral characteristics, as well as multi-element data on the Permian No. 3 Coal from the Sucun and Gaohe Mines, Changzhi City, southern Qinshui Basin. The studied coals are characterized by low- to medium-ash yield (Ad = 5.72%- 28.18%, 12.34% on average), low volatile matter yield (Vdaf = 8.49–15.17%, 10.96% on average), suggesting a low volatile bituminous coal to semi-anthracite. NH4-illite and kaolinite are the main minerals in the coals detected by XRD, and trace amount of minerals calcite, dolomite, quartz, pyrite and diaspore can also be found. The major elements of the studied No. 3 coals are dominated by SiO2 and Al2O3, ranging 2.49–16.45 wt% and 2.13–12.9 wt% (on a whole-coal basis), respectively. Li is enriched in the No. 3 coals (5

Abstract In this paper, silicon rich polycrystalline silicon carbide (poly-SiCx) thin films were prepared for passivating contact of silicon solar cells. The effect of different carbon doping ratios R [methane flow (sccm)/silane flow (sccm)] and the annealing temperatures on the passivation quality was investigated. The lifetime test showed that, given a lower annealing temperature, the passivation quality of poly-SiCx thin films was very poor at R over 0.2, and it can be improved by elevating the annealing temperature. The effective lifetime of over 1.8 ms can be obtained with implied open-circuit voltages (iVoc) of 715 mV and saturated dark current (J0) of 18 fA/cm2. The microstructure and optical property of poly-SiCx films was studied by Raman spectra, X-ray photoelectron spectroscopy and UV-VIS spectrophotometer. The results showed that the incorporation of carbon lowered the crystalline fraction of poly-SiCx and a higher annealing temperature was needed to achieve high crystallinity. The optical band gap of poly-SiCx was widened with increase in R, and got up to 2.3eV when R was 0.4. A proof-of-concept top/rear TOPCon solar cells, featuring a N+-poly-SiCx (R = 0.2) front contact, was fabricated to demonstrate the potential of this SiCx passivation contact. The decrease in the parasitic absorption of light at the front side resulted in higher photogenerated current. And the conversion efficiency of 20.17% was achieved.

Isolated cobalt atoms with CoN4configuration are decorated into a multichannel carbon matrix for efficient electrocatalytic oxygen reduction reaction.

Abstract Cu2BaSn(S,Se)4 (CBTSSe) solar cells are emerging photovoltaic devices due to their high theoretical efficiencies of ~31%, environment-friendly and earth-abundant composition, low density of non-recombination defects, and so on. However, the record efficiency of CBTSSe solar cell is only 5.2%, showing the importance of studying their performance via numerical analysis to further enhance their practical efficiencies. In this paper, the effect of absorber and buffer layers on performances of Cu2BaSnS4 (CBTS) solar cells are firstly systematically studied via the SCAPS-1D software to provide a platform for the study of the effect of MoS2 interlayer on the performances of CBTS solar cells. The highest PCE of CBTS solar cell with a 30 nm CdS buffer layer is 11.87%. The PCE of CBTS solar cell with a 0.8 μm CBTS absorb layer is 12.51%, indicating that the CBTS solar cell is a potential low-cost solar cell due to its large optical absorption coefficient (α > 104 cm−1). The efficiency of CBTS solar cell is improved to 16.47% when the carrier concentration of CBTS is 1016 cm−3. The relationship between the performance of solar cell and the band gap, thickness, donor concentration, acceptor concentration of MoS2 interlayer is systematically investigated on the basis of the optimized efficiency. It is found that MoS2 interlayer plays an important role in the performance of CBTS solar cell. The p-type MoS2 has a beneficial effect on the efficiency improvement while the n-type MoS2 has a negative effect on the efficiency enhancement. The highest PCE of CBTS solar cell is as high as 18.28% when the thickness and the acceptor concentration of MoS2 are 4 nm and 1019 cm−3, respectively. Our simulation result provides a promising research direction to further improve the actual efficiency of the CBTS solar cell.

Ferrocene was introduced as a solid additive in organic solar cells (OSCs). The use of ferrocene provides PM6:Y6 based device with improved performance and stability, demonstrating its great potential in the fabrication of efficient and stable OSCs.

A new small molecule acceptor, Y18, was designed and synthesized. Over 17% efficiency was obtained with single junction solar cells based on Y18.