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Sandy cropland ecosystems are major terrestrial ecosystems in semi-arid regions of northern China's Horqin Sandy Land, where they play an important role in the regional carbon balance. Continuous observation of the CO2 flux was conducted from 2014 to 2018 using the eddy covariance technique in a sandy maize cropland ecosystem in the Horqin Sandy Land. We analyzed carbon fluxes (the net ecosystem exchange (NEE) of CO2, ecosystem respiration (Reco), and the gross primary productivity (GPP) and their responses to environmental factors at different temporal scales using Random Forest models and correlation analysis. We found that the sandy cropland was a carbon sink, with an annual mean NEE of –124.4 g C m−2 yr−1. However, after accounting for carbon exports and imports, the cropland became a net carbon source, with net biome production ranging from –501.1 to –266.7 g C m−2 yr−1. At a daily scale, the Random Forest algorithm revealed that photosynthetic photon flux density, soil temperature, and soil moisture were the main drivers for variation of GPP, Reco, and NEE at different integration periods. At a monthly scale, GPP and Reco increased with increasing leaf area index (LAI), so the maize ecosystem's carbon sequestration capacity increased with increasing LAI. At an annual scale, water availability (precipitation and irrigation) played a dominant role in explaining inter-annual variability of GPP and Reco. Affected by climate (e.g., precipitation) and field management (e.g., cultivation, irrigation), carbon fluxes differed greatly between years in the maize system. [ABSTRACT FROM AUTHOR]

In order to suppress the overpressure and flame damage caused by the explosion of premixed methane-air, a self-built duct with a 10 × 10 × 100 cm was used to conduct an experimental study on the explosive characteristics and propagation rules of 9.5% methane under the effect of different porous materials at a fixed position. The methods of suppressing methane-air explosion in confined space are optimized. By analyzing the effect of porosity and distance of the porous material on the explosion, the overpressure and flame propagation characteristics after the methane-air explosion and under the influence of the dual factors are studied. It provides data support to explain the mechanism of blocking and suppressing premixed methane-air explosion when porous materials with different porosity and different positions. Studies have shown that the different porosity of porous materials and the position from the explosion source have significant and different effects on the propagation of overpressure and flame. The 10 PPI porous material has a strong promoting effect on the overpressure and flame propagation after the explosion, it accelerates the overpressure rising rate and increases the overpressure peak, and enhances the turbulence intensity of the explosion flame and accelerates the flame propagation rate. The 20 PPI porous material failed to suppress the explosion during the acceleration phase, but had certain suppression on the explosion flame in other phases. The effect of 30 PPI porous material to suppress explosion overpressure and flame depends on where it is placed. Both 20 PPI and 30 PPI porous materials can quench the flame and block the propagation of high-temperature carbonaceous products. This research results have theoretical value and guiding significance for the prevention and emergency treatment of methane explosion accidents. [ABSTRACT FROM AUTHOR]

Spontaneous electricity generator using moisture in ambient air has been developed rapidly in recent years for its great potential in self-sustained systems. However, due to the lack of efficient and continuous ion transport, the power-generation ability and stability from existing materials are unsatisfactory (ultra-low current, intermittent voltage and strong dependence on moisture) for practical applications. Here we report a generator made of ionic wood processed from natural wood using a simple and effective strategy to form continuous nanostructures with LiCl salts like spider webs around the inner walls of wood microchannels (i.e., fiber lumina). A single generator spontaneously produced a sustainable voltage of around 750 mV with a useful current of around 712 μA in ambient environment. And it also exhibited outstanding stability even when ambient humidity suddenly decreased to below 10% and stayed for 10 h. Besides, a connected system consisting of only six components outputted a voltage up to 4.40 V and current up to 4.16 mA, which can power LED lights. Our ionic wood shows promise for ambient moisture-energy conversion to develop the next self-sustained power system, with low-cost, sustainability and easily larger-scale productions. We investigate herein a hydroelectric device made of ionic wood that can spontaneously produce a useful stable electricity (e.g. 712 μA current) from ambient humidity. The ionic wood processed directly from natural wood by a simple effective strategy to form unique nanostructures like spiderwebs on the inner walls of microchannels. The generator exhibited exceptional stability even under harsh ambient humidity compared to the exiting materials. [Display omitted] • High strength aerogel wood was made directly from natural wood by a simple strategy. • Ionic wood has unique ionic nanostructure like spiderwebs on inner walls of channels. • A generator made of ionic wood outputs a useful power with charge-discharge behaviors. • Electrical output shows exceptional stability even in an extreme humidity environment. [ABSTRACT FROM AUTHOR]

Background: Annual herbs are crucial components of sandy ecosystems and their community assembly in arid sandy dunes is an intuitive indicator of a degraded ecosystem's successful restoration. In sandy areas, biocrust and sand burial often co-occur, given the higher diversity and biomass of annual herbs where both factors co-occur than where either does alone. Yet our knowledge of the underlying mechanism is limited. Methods: A field survey was conducted to verify that the presence of biocrust and sand burial jointly promoted the assembly of herbs. And then controlled simulating experiments were conducted to investigate the individual and collective effects of three biocrusts (bare sand (control), cyanobacterial crust, and moss crust) and three depths (0 (control), 2.5, and 5 mm) of sand burial upon germination, growth of three annual herbs as well as the soil water and nutrition status in a revegetated area of the Tengger Desert. Results: Biocrust inhibited seed germination of the three annual herbs, but promoted their seedling growth. However, sand burial disrupted the inhibitory influence upon seed germination and strengthened the positive effects of biocrust on seedling growth of all species, by improving the availability of water and nutrients in upper soil. Conclusion: Mutual complementary effects of biocrust and sand burial promote the establishment, and overall recruitment success of annual herbs. This finding emphasizes the importance of buried disturbance of biocrust in plant community assembly processes, providing an approach to disentangle relationships between biocrust and vascular plants, and a new technique suggestion for ecological restoration in arid sandy areas. [ABSTRACT FROM AUTHOR]

[Display omitted] • 1784 soil samples were collected from 330 soil profiles throughout the QTP desert. • The percentage of SOC in the topsoil was the highest reported to date at 54%. • Vertical distributions of SOC and nutrients can be fitted with functional models. • Topsoil stoichiometry was primarily influenced by vegetation and precipitation. • Subsoil stoichiometry was influenced primarily by soil silt and precipitation. The ecological stoichiometric properties of desert soils determine nutrient availability and contribute to biodiversity and ecosystem stability. We obtained 1784 soil samples from 330 soil profiles distributed across the desert area of the Qinghai–Tibet Plateau (QTP). We measured the content of soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), alkali-hydrolyzed nitrogen (AN), available phosphorus (AP), and available potassium (AK) to elucidate the vertical patterns of soil stoichiometric characteristics and their driving factors. We found a unique vertical distribution of SOC and soil nutrients in the QTP desert ecosystem: the proportions of SOC and nutrient storage in the topsoil (0–20 cm) were the highest that have been reported to date, especially for the proportion of SOC , which reached 54 %. The vertical distributions of SOC and AN fit an exponential function (r = 0.247 and 0.249), TN fit a linear function (r = 0.115), and TP , AP , and AK fit a curvilinear function (r = 0.127, 0.175, and 0.103), indicating that soil components exhibited a depth-dependent distribution in the alpine desert ecosystem. With increasing soil depth, C:N and C:P decreased significantly, AN:AP first increased and then decreased, and AP:AK first decreased and then increased. The factors that influenced soil nutrients and stoichiometry differed between the topsoil (0–20 cm) and deep soil (20–100 cm) layers. In the topsoil (0–20 cm), vegetation and precipitation were the dominant factors for soil nutrients and stoichiometry, while topography and climate affected soil nutrients and stoichiometry indirectly by influencing vegetation growth. In the deep soil (20–100 cm), silt particles and precipitation were the dominant factors for soil nutrients and stoichiometry, but climate affected soil nutrients and stoichiometry indirectly, mainly by influencing soil texture. The inconsistencies of nutrient stoichiometric driving mechanisms in surface and deep soils contributed to a comprehensive understanding of soil stoichiometric properties at the profile scale of desert ecosystems. [ABSTRACT FROM AUTHOR]

• CF 3 CHFCF 3 has an enhancing and inhibiting effect on premixed methane-hydrogen deflagration. • The chain transfer reactions R333 and R343 had a non-negligible impact on inhibiting hydrogen-methane-air deflagration. • The deflagration inhibition mechanism of CF 3 CHFCF 3 on hydrogen-methane-air can be divided into three phases. To establish the suppression mechanism of CF 3 CHFCF 3 on a premixed hydrogen-methane deflagration, the process was systematically explored by experimental and chemical kinetics simulation. The results show that CF 3 CHFCF 3 has a beneficial suppression effect on the hydrogen-methane deflagration with 20 % H 2 addition at the equivalence ratios of 0.8, 1.0, and 1.2 of premixed fuel. This suppression process is divided into three phases. First, there is the physical inhibition phase. The addition of CF 3 CHFCF 3 acts as dilution and cooling. Then, there was the chemical thermal promotion phase. The fluorides produced by the pyrolysis of CF 3 CHFCF 3 , such as C 3 F 7 , CF 3 CHF, C 3 F 7 O, and CF 3 , release an enormous amount of heat while participating in the reaction of the combustion system, which promotes the forward chain reaction of the combustion system. Finally, there is the chemical inhibition phase. Fluorides consume an immense number of active radicals and generate unreactive radicals to inhibit hydrogen-methane-air deflagration. Furthermore, the accumulated unreactive gases, such as HF and CO 2 , become a new third-body dilution reactant concentration. This study provides insight into the process of CF 3 CHFCF 3 inhibition and renders theoretical guidance for the explosion protection of hythane. [ABSTRACT FROM AUTHOR]

• Soil microbial community compositions were affected by fertilizers. • Fertilizer had greater impact on soil bacterial than on fungal community. • The fungal community was more stable than the bacterial community. • Main driving indicator of microbiota was soil pH. • Chemical fertilizer plus manure was best in structuring bacterial communities. Soil microorganisms play an important role in the energy flow and nutrient cycling between soil and plants, but the impact of fertilizers on soil bacterial and fungal communities in sandy agroecosystems remains uncertain. We hypothesized that fertilizers affect soil microbial communities through soil properties and plant leaf C:N:P stoichiometry. To test this hypothesis in a sandy farmland ecosystem on the Mongolian Plateau, soil microbial diversity and composition, soil properties and plant leaf C:N:P stoichiometry were examined following 4 years of one of six fertilizer treatments (no fertilizer; returning straw; chemical fertilizer; manure; half quantity of chemical fertilizer and manure; and half quantity of chemical fertilizer). The soil bacterial Shannon index was lowest with chemical fertilizer and half quantity of chemical fertilizer, while fungal Chao richness and phylogenetic diversity (PD) index were lowest with chemical fertilizer. However, chemical fertilizer combined with manure increased the soil bacterial Shannon and PD indices, while manure alone improved fungal Chao richness and the PD index. Fertilizers had a greater impact on the soil bacterial community than on the fungal community and the fungal community was more stable than the bacterial community. Based on redundancy analysis (RDA), total soil carbon, soil nitrogen, leaf carbon, leaf N:P, pH and 16S rRNA gene copy numbers affected the soil microbial community. Structural equation models (SEM) demonstrated that soil pH was a strong driving indicator of soil microbial community under fertilization in a sandy farmland ecosystem. Chemical fertilizer combined with manure out-performed other fertilizers in structuring soil bacterial communities, while chemical fertilizer alone was the worst in maintaining soil microbial communities. Results from this study provide a basis for fertilization management strategies in maintaining below-ground microbial diversity and in ensuring sustainable land development of sandy agroecosystems. [ABSTRACT FROM AUTHOR]

In order to promote low-carbon sustainable development in the ecological environment and improve the efficiency of hydrogen and natural gas energy utilization, this project carried out research on the explosive effects of different thicknesses of ordered porous media on the hydrogen-methane gas mixture. A detailed discussion was conducted based on the critical quenching hydrogen blending ratio under the thicknesses of 50 mm and 60 mm of ordered porous media. The results indicate that the critical quenching hydrogen blending ratio is 9% for a thickness of 50 mm and 20% for a thickness of 60 mm, indicating that greater thickness enhances flame suppression capabilities. Between the critical quenching hydrogen blending ratio range for thicknesses of both 50 mm and 60 mm, the peak values of flame front velocity, reverse diffusion flame length, and explosion pressure initially decrease and then subsequently increase with an increasing hydrogen content. As the thickness of the flame retardant medium augments, there is an increase in both the flame velocity and the reverse diffusion length at the critical hydrogen concentration. However, the pressure peak observed at a thickness of 50 mm surpasses that at 60 mm. The pressure curve experiences sudden fluctuations due to the combined effects of explosion pressure and heat transfer, with the initial point of this abrupt change closely linked to the thickness of the ordered porous media. Therefore, it is imperative to maintain hydrogen content below the critical quenching hydrogen blending ratio to ensure the safe transport and utilization of hydrogen and natural gas energy., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Soil fauna is closely linked to ecological functions such as biogeochemical cycling, soil structure, ecosystem sustainability and trophic interactions. However, little consideration has been given to how desertification influences the abundance and diversity of soil fauna in arid areas. In this study, soil fauna was sampled in four desert habitats (gravel, sand, salt and mud desert) in northwest China. At the same time, the plant traits, geographic location and soil properties were investigated. We also measured contribution of environmental factors explained faunal community diversity and abundance, and by what pathways desertification controls soil fauna. The results showed that total abundance and diversity of soil fauna in the mud desert were significantly (P < 0.05) higher than salt, sand and gravel deserts. Soil fauna diversity, composition and community were more sensitive to desertification-induced changes in soil properties than to changes in plant traits and geographic locations (changes in soil properties explained 68.9 % and 73.7 % of the variation in diversity and abundance of soil fauna community, respectively). Among them, the available phosphorus, volumetric water content had a significant positive effect on community diversity and abundance, while pH had a significant negative effect (P < 0.01). The results of piecewise structural equation modeling imply that desertification may have mainly indirect impacts on soil fauna community, and that direct effects are almost zero. In summary, regardless of the type of desertification, it will affect the material cycle, energy flow and information transfer of ecosystems by destroying the soil habitats and vegetation conditions, and will affect the structure and diversity of soil fauna from the bottom up., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background and Aims: Non-structural carbohydrates (NSC), primarily sugars and starch, play a crucial role in plant metabolic processes and a plant's ability to tolerate and recover from drought stress. Despite their importance, our understanding of NSC characteristics in the leaves of plants that thrive in hyper-arid and saline environments remains limited., Methods: To investigate the variations in leaf NSC across different species and spatial scales, and to explore their possible causes, we collected 488 leaf samples from 49 native plant species at 115 sites in the desert area of northwestern China. The contents of soluble sugars (SS), starch, and total NSC were then determined., Key Results: The average contents of SS, starch, and total NSC were 26.99, 60.28, and 87.27 mg g-1 respectively, which are much lower than those reported for Chinese forest plants and global terrestrial plants. Herbaceous and woody plants had similar NSC levels. In contrast, succulent halophytes, a key component of desert flora, showed significantly lower leaf SS and total NSC contents than non-succulent plants. We observed a strong negative correlation between leaf succulence and SS content, suggesting a role of halophytic succulence in driving multi-species NSC pools. Environmental factors explained a minor portion of the spatial variation in leaf NSC, possibly due to the narrow climatic variation in the study area, and soil properties, particularly soil salinity, emerged as more significant contributors., Conclusions: Our findings increase the understanding of plant adaptation to drought and salt stress, emphasizing the crucial role of halophytic succulence in shaping the intricate dynamics of leaf NSC across diverse plant species in arid and hyper-arid environments., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Conducting polymers can be dynamically switched between being optically metallic (negative real permittivity) and dielectric (positive real permittivity) by varying their redox state. This has enabled nanoantennas with plasmonic resonances that can be reversibly turned on/off, opening for applications in dynamic metaoptics, reflective displays, and smart windows. However, previous reports on conducting polymer plasmonics were limited to p-type polymers. Here, we show that a highly conducting n-type polymer, called poly(benzodifurandione) (PBFDO), can also provide optically metallic properties and be used to make dynamic optical nanoantennas. The doped version of the polymer becomes metallic at wavelengths above around 700 nm, leading to plasmonic extinction peaks for nanodisks made from the material. These peaks can be reversibly switched off and on electrically or chemically by varying the doping level of the polymer. The study extends the field of dynamic polymer plasmonics to n-type materials and broadens the application areas of PBFDO., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Converting hierarchical biomass structure into cutting-edge architecture of electrocatalysts can effectively relieve the extreme dependency of nonrenewable fossil-fuel-resources typically suffering from low cost-effectiveness, scarce supplies, and adverse environmental impacts. A cost-effective cobalt-coordinated nanocellulose (CNF) strategy is reported for realizing a high-performance 2e-ORR electrocatalysts through molecular engineering of hybrid ZIFs-CNF architecture. By a coordination and pyrolysis process, it generates substantial oxygen-capturing active sites within the typically oxygen-insulating cellulose, promoting O 2 mass and electron transfer efficiency along the nanostructured Co 3 O 4 anchored with CNF-based biochar. The Co-CNF electrocatalyst exhibits an exceptional H 2 O 2 electrosynthesis efficiency of ≈510.58 mg L -1  cm -2  h -1 with an exceptional superiority over the existing biochar-, or fossil-fuel-derived electrocatalysts. The combination of the electrocatalysts with stainless steel mesh serving as a dual cathode can strongly decompose regular organic pollutants (up to 99.43% removal efficiency by 30 min), showing to be a desirable approach for clean environmental remediation with sustainability, ecological safety, and high-performance., (© 2024 Wiley‐VCH GmbH.)

Harvesting energy from air water (atmospheric moisture) promises a sustainable self-powered system without any restrictions from specific environmental requirements (e.g., solar cells, hydroelectric, or thermoelectric devices). However, the present moisture-induced power devices traditionally generate intermittent or bursts of energy, especially for much lower current outputs (generally keeping at nA or μA levels) from the ambient environment, typically suffering from inferior ionic conductivity and poor hierarchical structure design for manipulating sustained air water and ion-charge transport. Here, we demonstrate a universal strategy to design a high-performance bilayer polyelectrolyte ion paper conductor for generating continuous electric power from ambient humidity. The generator can produce a continuous voltage of up to 0.74 V and also an exceptional current of 5.63 mA across a single 1.0 mm-thick ion paper conductor. We discover that the sandwiched LiCl-nanocellulose-engineered paper promises an ion-transport junction between the negatively and positively charged bilayer polyelectrolytes for application in MEGs with both high voltage and high current outputs. Moreover, we demonstrated the universality of this bilayer sandwich nanocellulose-salt engineering strategy with other anions and cations, exhibiting similar power generation ability, indicating that it could be the next generation of sustainable MEGs with low cost, easier operation, and high performance.

Biological soil crusts (biocrusts) are considered "desert ecosystem engineers" because they play a vital role in the restoration and stability maintenance of deserts, including those cold sandy land ecosystems at high latitudes, which are especially understudied. Microorganisms participate in the formation and succession of biocrusts, contributing to soil properties' improvement and the stability of soil aggregates, and thus vegetation development. Accordingly, understanding the composition and successional characteristics of microorganisms is a prerequisite for analyzing the ecological functions of biocrusts and related applications. Here, the Hulun Buir Sandy Land region in northeastern China-lying at the highest latitude of any sandy land in the country-was selected for study. Through a field investigation and next-generation sequencing (Illumina MiSeq PE300 Platform), our goal was to assess the shifts in diversity and community composition of soil bacteria and fungi across different stages during the succession of biocrusts in this region, and to uncover the main factors involved in shaping their soil microbial community. The results revealed that the nutrient enrichment capacity of biocrusts for available nitrogen, total nitrogen, total phosphorus, total content of water-soluble salt, available potassium, soil organic matter, and available phosphorus was progressively enhanced by the succession of cyanobacterial crusts to lichen crusts and then to moss crusts. In tandem, soil bacterial diversity increased as biocrust succession proceeded but fungal diversity decreased. A total of 32 bacterial phyla and 11 fungal phyla were identified, these also known to occur in other desert ecosystems. Among those taxa, the relative abundance of Proteobacteria and Cyanobacteria significantly increased and decreased, respectively, along the cyanobacterial crust-lichen-moss crust successional gradient. However, for Actinobacteria, Chloroflexi, and Acidobacteria their changed relative abundance was significantly hump-shaped, increasing in the shift from cyanobacterial crust to lichen crust, and then decreasing as lichen crust shifted to moss crust. In this process, the improved soil properties effectively enhanced soil bacterial and fungal community composition. Altogether, these findings broaden our understanding about how soil microbial properties can change during the succession of biocrusts in high-latitude, cold sandy land ecosystems., (© 2024. The Author(s).)

Assembly ubiquitously occurs in nature and gives birth to numerous functional biomaterials and sophisticated organisms. In this work, chiral hydrogen-bonded organic-inorganic frameworks (HOIFs) are synthesized via biomimicking the self-assembly process from amino acids to proteins. Enjoying the homohelical configurations analogous to α-helix, the HOIFs exhibit remarkable chiroptical activity including the chiral fluorescence (g lum  = 1.7 × 10 -3 ) that is untouched among the previously reported hydrogen-bonded frameworks. Benefitting from the dynamic feature of hydrogen bonding, HOIFs enable enantio-discrimination of chiral aliphatic substrates with imperceivable steric discrepancy based on fluorescent change. Moreover, the disassembled HOIFs after recognition applications are capable of being facilely regenerated and self-purified via aprotic solvent-induced reassembly, leading to at least three consecutive cycles without losing the enantioselectivity. The underlying mechanism of chirality bias is decoded by the experimental isothermal titration calorimetry together with theoretic simulation., (© 2024. The Author(s).)

Background: Microbial colonization represents one of the main threats to the conservation of subterranean cultural heritage sites. Recently, the microbial colonization on murals in tombs has gradually attracted attention., Methods: In this study, a total of 33 samples, including 27 aerosol samples and 6 mural painting samples, were collected from different sites of Xu Xianxiu's Tomb and analyzed using culture-dependent methods. We compared the diversities of culturable bacteria and fungi isolated from the air and murals and explored the potential impacts of microorganisms on the biodeterioration of the murals., Results: Phylogenetic analyses revealed that the culturable bacteria belonged to Bacillus, Microbacterium, Lysobacter and Arthrobacter. And the most of fungal belonged to the Penicillium, Cladosporium and Aspergillus genera. The composition and structure of airborne bacteria and fungi outside the tomb were both significantly different from that inside the tomb. The variation trends of airborne bacterial and fungal concentrations at different sampling sites were remarkably similar. Bacillus frigoritolerans, Bacillus halotolerans, Bacillus safensis, Exiguobacterium mexicanum, Microbacterium trichothecenolyticum, and Micrococcus yunnanensis were bacterial species commonly isolated from both the mural and air environments. Fungal species commonly isolated from aerosol samples and mural painting samples were Alternaria alternata, Cladosporium cladosporioides, Penicillium brevicompactum, and Peyronellaea glomerata. The prediction of the ecological functions of the bacteria revealed that chemoheterotrophy or aerobic&#95;chemoheterotrophy accounted for substantial relative proportions in all sample types., Conclusion: These results suggest that the aerosol circulation between the inside and outside environments of the tomb was weak and that the outside environment had yet to have an impact on the air microbial community inside the tomb. Selective colonization of microorganisms, which is mediated by interaction between microorganisms and special microenvironmental factors, is an important reason for the biodeterioration of murals., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Liu, Wu, Xiang, Ma, He, Zhang, Wang, Duan, Tian and Feng.)