Elevated Areas Research Articles

Interaction law between mining stress and fault activation and the effect of fault dip angle in longwall working face

Study of the interaction between fault activation and mining stress evolution in the longwall working face is helpful to provide a targeted area for fault type heavy mine pressure disaster control. Combining theoretical analysis, physical and numerical simulation, the mechanical mechanism of fault activation is analyzed, the interaction law between mining stress and fault activation is studied, and the influence of fault dip angle on the evolution of fault activation and mining stress is discussed. The minimum critical dip angles α of normal and reverse fault activation are π/4 + φ/2 and π/4-φ/2, respectively. During the mining process, the activation position of the fault surface, the peak values of stress and displacement gradually increase and transfer from the high position of the fault to the low position, and the peak value of the advance abutment pressure reaches the maximum at the fault. The advancing distance of the working face required for fault activation gradually decreases with the decrease of the fault dip angle, and the peak elevation area of the working face gradually increases with the decrease of the fault dip angle. Combined with the on-site microseismic monitoring results, it can be seen that when the working face is about 20 m away from the fault, the stress and energy increase sharply, which is the main control area of the impact disaster.

Air‐Pyrolysis Precision Synthesis of Functional Porous Carbon Materials

AbstractCarbon materials play a pivo tal role across various advanced applications, yet their synthesis traditionally necessitates inert atmospheres to avert oxidation at high temperatures, thus inflating production costs and resource utilization. Achieving precision synthesis of functional porous carbon materials via air‐pyrolysis remains a formidable challenge. Herein, a streamlined, one‐step lava‐like carbonization approach is introduced enabling the fabrication of porous carbons boasting tailored morphologies (0‐3D), elevated specific surface areas (540.7–1047.6 m2g⁻¹), heteroatom doping, and commendable carbon yields (20‐39.1%) through direct pyrolysis within an air environment. Leveraging recyclable boric acid as a reaction medium, a lava‐like flowing protective barrier above 170 °C is engendered that spontaneously creates an oxygen‐free‐like milieu devoid of high pressure or intricate procedures. This boron‐containing lava serves dually as a template and chemical activator, facilitating pore formation and catalyzing porous carbon production. Notably, the method accommodates a spectrum of carbon sources, encompassing sugars, proteins, graphene oxide, and their metal mixtures. The resultant morphologically customizable carbons exhibit excellent performance in areas as diverse as microwave absorption and electrocatalysis. This work pioneers a novel pathway for large‐scale precision synthesis of high‐quality carbon materials via air‐pyrolysis under mild conditions.

Exploring Topography Downscaling Methods for Hyper‐Resolution Land Surface Modeling

AbstractHyper‐resolution land surface modeling provides an unprecedented opportunity to simulate locally relevant water and energy cycles. However, the available meteorological forcing data is often insufficient to fulfill the requirements of hyper‐resolution modeling. Here, we developed a comprehensive downscaling framework based on topography‐adjusted methods and automated machine learning (AutoML). With this framework, a 90 m and hourly atmospheric forcing data set was developed from ERA5 data at a 0.25° resolution, and the Common Land Model (CoLM) was then forced with the developed forcing data over two complex terrain regions (the Heihe River Basin and Upper Colorado River Basin). We systematically evaluated the downscaled forcing and the CoLM outputs against both in situ observations and gridded data. The ground‐based validation results suggested consistent improvements for all downscaled forcing variables with mean RMSE improved by 6.362%–95.86%. The downscaled forcings, which incorporated detailed topographic features, offered improved magnitude estimates, achieving a comparable level of performance to that of regional reanalysis forcing data. The downscaled forcing driving the CoLM model showed comparable or better skills in simulating water and energy fluxes, as verified by in situ validations. The hyper‐resolution simulations provided a detailed and more reasonable description of land surface processes and attained similar spatial patterns and magnitudes with high‐resolution land surface data, especially over highly elevated areas. Additionally, this study highlighted the benefits of using mountain radiation theory‐based shortwave radiation downscaling models and AutoML‐assisted precipitation downscaling models. These findings emphasized the significance of integrating topography‐based downscaling methods for hillslope‐scale simulations.

Mapping cellular coverage suitability: a GIS-Based approach to identifying poor service areas

Cellular coverage is a critical component of modern telecommunications, providing essential services for communication, commerce, and emergency response. Despite its importance, many regions, particularly those with challenging terrain or low population density, experience inadequate cellular service. This study focuses on the commune of Laghouat, Algeria, employing a GIS-based Multi-Criteria Analysis (MCA) to assess cellular coverage suitability. Using ArcGIS Pro, four key factors were integrated: cell tower locations, terrain elevation, population distribution, and restricted areas. The methodology includes performing a Viewshed analysis to identify dead zones, converting population data into raster format to map demand, and digitizing restricted areas where telecommunication infrastructure development is prohibited. All factors were standardized to a common scale to ensure comparability and a weighted overlay analysis was conducted to generate a comprehensive suitability map. The map highlights areas of poor cellular coverage, guiding the placement of new infrastructure. Additionally, the research considers regulatory restrictions on land use, ensuring compliance with governmental policies. The resulting suitability map provides valuable insights for telecommunications providers and policymakers, enabling them to target underserved regions for infrastructure improvements while adhering to legal constraints. This study offers a robust, scalable framework for identifying and addressing cellular coverage gaps, applicable to other regions with similar geographic and demographic challenges.

MODELLING GBM RECURRENCE: THE INflUENCE OF PERI-LESIONAL OEDEMA AND THE DISCONNECTOME

Abstract AIMS Residual tumour burden after surgery in GBM patients is a prognostic imaging biomarker, often involving the area of T2 signal elevation surrounding the tumour core, histopathologically representing infiltrative oedema with tumour cells. We present the first stage of a model to improve the prediction GBM recurrence by specifically investigating the peri-lesional oedema compartment. METHOD UK-wide sample of histologically proven IDHwt GBMs with MRIs at the time of diagnosis underwent state-of- the-art in-house tumour segmentation pipeline and radiomic feature extraction of whole-tumour, enhancing, non-enhancing and oedema components, and masked disconnectome map components. Of these, early GBM recurrence, within 6 months after completion of radiotherapy, was curated and distribution mapped across the brain. RESULTS 1464 patients were identified: male = 901, median age 63 years, average overall survival 597 days. The radiomic features: Compactness 1 and 2, Surface Area, Spherical Disproportion, Sphericity, and Maximum 2D Diameter column of the disconnectome-related perilesional oedema compartment were most predictive of survival outcome (p value <0.01). Of these, 47 patients with average overall survival 357 days and average time from end of radiotherapy to progression of 131 days were identified. CONCLUSION Our early results reveal the relationship between perilesional oedema MRI features and survival, with disconnectome-related perilesional oedema features most predictive. This suggests that extended brain network aberrations caused by gliomas may also influence tumour recurrence. Further work will focus on the development of more robust predictive models of tumour recurrence that have potential for significant impact on surgical and radiotherapy planning.

Geologic Evolution of Imdr Regio, Venus: Insight Into the Origin of a Possible Young/Active Hot Spot

AbstractLarge topographic rises on Venus are regions thought to be formed in response to the presence of a mantle plume or mantle upwelling, equivalent to hot spots on Earth. In this work, we study the geology and evolution of one of these large topographic rises, Imdr Regio, based on geologic mapping and analysis of geophysical data of the area. Imdr Regio presents a complex structure with two very different areas: (a) an elevated southeast area that is dominated by volcanism associated with Idunn Mons, a large volcano that has been proposed as a site of recent or even active volcanism; (b) another elevated area in the northwest area that also has a large volcano (Arasy Mons), but that is dominated by volcanism and tectonic activity associated with the formation of the Olapa Chasma rift system. These two very differentiated topographically elevated areas also exhibit differences in their geology, volcanic and tectonic style, and geophysical characteristics, which leads us to suggest that more than the classic volcano‐dominated rise classification attributed to Imdr Regio the area could rather be considered as an intermediate or hybrid volcano‐rift dominated large topographic rise. The evaluation of the different genetic scenarios and its correspondence with the observed geology in the area suggests that the complex geology of Imdr Regio could be better explained if we consider models of hot spot evolution that involve the presence of several mantle plumes or secondary upwellings derived from a mantle plume emplaced at a deeper rheological boundary.

Basement Depth Map Estimation and Linear Features Detection Depending on Interpretation of Magnetic Data at Qarun Oil Field and Surrounding Areas, North Western Desert, Egypt

This investigation primarily targets a specific area situated in the northeastern Western Desert and northwest Beni-Suef, covering Wadi Al Rayan area, Gindi basin, Kattaniya inversion, and El-Fayum depression. It extends to the east of the river Nile. This study aims to Evaluate the depth of the basement complex in the area under investigation. The total aeromagnetic intensity data was reduced to the north pole (RTP) for clarity. 2D modeling of this RTP data was then used to evaluate the basement depth. The analysis of basement depth maps revealed significant variations in the subsurface structure of the study area, showing both elevated features (horsts) and depressed areas (grabens). The elevated basement (horsts) was found to be at a depth of approximately 813 meters, while the deepest depression (grabens) reached down to 7600 meters. Based on magnetic data combined with eight wells drilled into the basement complex, a basement lineament map of the area is delineated as a result of the investigation. This map shows a series of large alternating highs and valleys in ENE-WSW, NE-SW and E-W trending bands. Together with other minor trends, these major trends have shaped the basement surface into several tilted fault blocks, creating anticlinal and syncline zones of different depths and directions to form the Qattrani-El Gindi low trends. Whereas the high trend is located in El Fayum, El-Sagha, and Abu Rawash areas. The study helped to re-evaluate the subsurface structures affecting the Qarun oil field's hydrocarbon accumulation.

Toward the reliable use of reanalysis data as a reference for bias correction in climate models: A multivariate perspective

General circulation models are vital tools in climate change research, profoundly influencing numerous hydroclimatological studies, but often exhibit systematic biases due to limitations in parameterization. To correct these biases, bias correction (BC) methods, which are heavily dependent on the quality of historical reference data, are employed. Ideally, accurate data comes from a dense network of gauges, but due to their limited availability, reanalysis data is frequently used instead. Although reanalysis data provides consistent global and temporal coverage, its assimilated nature can introduce additional biases, potentially increasing error propagation particularly in the multivariate perspective. Thus, this study investigates the reliability of reanalysis data as a reference for multivariate bias correction (MBC) and utilizes a two-stage bias correction approach that integrates both gauge and reanalysis data to leverage their respective strengths. Conducting a case study in South Korea, we utilized gauge data, ERA5 reanalysis data, and outputs from 10 CMIP6 General Circulation Models. We implemented three-nested experiments to test the robustness of this two-stage approach across various dimensions. Results show that using reanalysis data as a reference can lead to bias propagation, especially misrepresenting precipitation and wind dependencies in high elevation areas. However, the two-stage approach has shown an enhancement in mitigating these limitations, even when gauge data is temporally sparse, and across different combinations of MBC methods. Finally, we highlight the current limitations and potential for future research to focus on effectively combining gauge and reanalysis data to compensate for each other’s weaknesses, thereby enhancing the accuracy and reliability in future climate realizations.

Spatial distribution of available phosphorus in surface road and trackway surface materials on a sheep farm in Ireland

Farm roadway runoff is a high-risk source of pollution when connectivity with waters occurs. Nutrients in this runoff are dominated by fresh animal deposits, but recent dairy and beef farm studies showed that available phosphorus (P) accumulates in roadway surface material and can be lost in runoff. A current knowledge gap is to examine available P concentrations in unsealed roadway and trackway (non-maintained) network of a lowland sheep farm. The present study focused on a 45 ha farm stocked with 544 sheep in south-east Ireland. Ten locations were sampled along with the adjacent fields for available P (i.e., Morgan’s P) and ancillary parameters (e.g., pH, total P and heavy metals) in December 2022. The first sampling location was on an aggregate roadway and the other nine were on trackways representing an older aggregate roadway network used by the flock but now covered with soil and grass. Results showed a distinct difference in surface material pH between roadway and trackway locations. Trackways had a pH that mimicked adjacent fields around the agronomic optimum for grassland of ∼6.2. All sampling locations had elevated available P concentrations, ranging from 26.3 to 111.0 mg L−1 (mean 62.8 mg L−1), similar to the spatial distribution for dairy farms but above those found at beef farms previously studied. The highest available P concentrations were found in roadway and trackway sections adjacent to the farmyard. Other elevated sampling areas were on trackways (87.3 or 97.7 mg P L−1) away from the farmyard where sheep are funnelled to pasture, stop to seek shade, urinate and defecate but do not graze. By contrast the average available P concentration for the surrounding fields was 8.4 mg L−1 with a range of 2.7–15.9 mg L−1. Two sampling areas combine to create a critical source area where a high available P source becomes visibly mobilised as runoff during rainfall, discharges into an open drainage ditch, which is then connected to a local stream. Breaking the pathway before runoff enters the open ditch could be a cheap and effective way of mitigating nutrient losses at these two locations.

The changing geography of wine climates and its implications on adaptation in the Italian Alps

AbstractWine production and quality both strongly depend on suitable climatic conditions. Increasing the climate resilience of wine regions is therefore of critical importance but requires instruments to evaluate shifts in climatic conditions and growing suitability. This evaluation is particularly challenging in mountain viticultural areas due to their complex topoclimatic patterns, yet they offer the possibility to analyze climate change impacts and adaptation strategies across various climatic conditions and cultivated varieties. Here, we assessed historical and future bioclimatic conditions and identified effective adaptation strategies toward more sustainable and climate‐resilient wine production in the mountain winegrowing regions within South Tyrol in the Italian Alps. We found significant changes in climatic conditions under future scenarios, such as an increase in the Huglin index (HI) and cool night index (CNI) as well as a decreased dryness index (DI), causing an expansion of suitable areas for viticulture as well as a spread of unprecedented climatic conditions in traditional vineyards. Impacts and suitable adaptation options varied depending on climate type and grape variety, highlighting the need for targeted solutions that balance the need for high‐quality wine production with environmental protection and sustainability. Higher elevated areas over 1000 m a.s.l. will experience an increased suitability raising the need for restrictions regarding the expansion of vineyards to avoid degradation of natural ecosystems and biodiversity declines. In contrast, many traditional winegrowing areas will need to implement a combination of short‐ and long‐term adaptation measures to maintain traditional wine styles. Our findings provide a framework for the assessment of viticultural suitability and the formulation of appropriate adaptation strategies for the sustainable cultivation of wine grapes in a changing climate that applies to a variety of climates and grape varieties.

Psoriasis treatment and biologic switching: The association with clinical characteristics and laboratory biomarkers over a 13-year retrospective study.

The advent of biologics has greatly improved patient outcomes, yet some patients are compelled to switch therapies. Predicting these therapeutic failures is important; however, the factors associated with switching biologics have not been fully explored. This study examined patterns and determinants of biologics switching in psoriasis treatment retrospectively over 13 years. We focused on the association between clinical characteristics, basal laboratory data, and frequency of biologics switching. The findings revealed that elevated Psoriasis Area Severity Index scores and the presence of arthritis were observed in patients who experienced two or more treatment switches compared with those without treatment switches. Moreover, neutrophil to lymphocyte ratio was associated with higher biologics switching rates, indicating that systemic inflammation significantly impacts treatment adherence. A treatment approach, taking into account both the clinical presentation and inflammatory biomarkers, may be important for optimizing patient management in psoriasis.

Thermal modeling of the lunar South Pole: Application to the PROSPECT landing site

Water ice is distributed on the surface and in the subsurface of the Moon, as confirmed by observational data, and predicted by several numerical models. In this respect, the direct search for lunar water is the main objective of the ESA’s PROSPECT package, that aims to analyze a region of interest at the lunar South Pole. PROSPECT, originally on the Russian Luna 27, is now on the CLPS (Commercial Lunar Provider Service) “CP” 22 mission. In this work, we applied our 3-D FEM thermophysical model to investigate the landing site selected for the CP 22 mission, which is centred at −84.496°S, 31.588°E, and located on the Leibnitz Plateau and within an area of high elevation. The purpose of our model is to investigate regions of interest (ROI) on the lunar surface by working with the real topography at the scale of 5 m, by using the DEM (Digital Elevation Model) of the region. Since the lunar surface is characterized by topographic variations such as craters or boulders, a 3-D model is preferable over a 1-D numerical model. We produced temperature maps of the surface and 1-D temperature vs depth, as well as we produced illumination maps, computing also the indirect contribution. These simulations will provide a complete thermophysical vision of the landing site, offering a theoretical support to the researchers and engineers of the CP 22 mission, and of future lunar missions. In addition, this model can be applied to every site of the Moon surface and subsurface and, in general, to any airless body of the Solar System.

Assessing the Impacts of Climate Change on Geographical Distribution of Tea (Camellia sinensis L.) in Kenya with Maximum Entropy Model

Climate change has been disturbing the present species distribution ranges, resulting in the shifting of cultivation areas and decreases in production and quality. Tea (Camellia sinensis L.), which seeks optimum climatic resources, is a key cash crop economically in Kenya. In this study, the shifting of tea suitability was projected with the MaxEnt model under the SSP (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) climate scenarios for the 2050s and 2090s relative to the 1970–2000 distribution. Analysis under the current climatic condition showed that the proportions of optimal and medium- and marginal-suitable areas were 2%, 3%, and 24% of the total area, respectively, and located in south-western (SW), central, and north-eastern (NE) Kenya and, to some extent, in the Rift Valley. It was projected that the potential suitable tea-growing areas would migrate from the western areas to the central, eastern, and north-eastern highlands in Kenya. It was detected that the precipitation of the driest period (July), precipitation of the wettest quarter (April, May, and June), and annual temperature range could be the main climatic factors determining the shift in tea distribution. Compared to the current distribution (29%), the climatically suitable areas for tea production could reach 32.58% of Kenya’s land area under the SSP1-2.6 scenarios in the 2050s and 35.08% in the 2090s under the SSP5-8.5 scenario. On the contrary, it was found that the optimal climate-suitable habitats were projected to shrink by 2% and 1% in the 2050s and 2090s under all scenarios on the west side of the Great Rift Valley compared to the current distribution. In comparison, the sizes of medium- and marginal-suitable habitats would increase by 1% and 3%, respectively. The findings indicated that unless adaptive climate actions are taken, climate change could reduce the tea planting areas in western Kenya. Meanwhile, climate suitability was projected to expand upward on the east side of the Rift Valley, enhancing the potential distribution of tea. The developed climate information could be used to design and implement adaptation interventions in the lower elevation areas. Finally, we highlight that the available scientific literature on the climate suitability of tea in Kenya should be broadened by adding non-climatic factors.

Exogenous Melatonin Alleviates Osmotic Stress by Enhancing Antioxidant Metabolism, Photosynthetic Maintenance, and Hormone Homeostasis in Forage Oat (Avena sativa) Seedlings

Melatonin (MT) is a multifunctional hormone that enhances crop resilience against various abiotic stresses. However, its regulatory mechanism of osmotic tolerance in forage oats (Avena sativa) plants under water-limited scenarios is still unclear. This study aimed to delineate the impact of MT pretreatment on the morphological, physiological, and biochemical functions of oat seedlings under osmotic stress. Our findings demonstrated that exogenous treatment of MT noticeably elevated leaf area while decreasing the root/shoot ratio of oat seedlings subjected to osmotic stress. Osmotic-induced 38.22% or 48.37% decrease in relative water content could be significantly alleviated by MT pretreatment on day 7 or day 14, respectively. MT treatment also significantly mitigated osmotic-induced decreases in photosynthetic parameters including net photosynthetic rate, stomatic conductance, and intercellular CO2 concentration as well as various chlorophyll fluorescence parameters, which could contribute to enhanced accumulations of free proline and soluble sugars in seedlings after being subjected to a prolonged duration of osmotic stress. Furthermore, MT markedly improved antioxidant enzyme activities including superoxide dismutase, ascorbate peroxidase, catalase, and peroxidase along with the accumulation of ascorbic acid contributing to a significant reduction in reactive oxygen species under osmotic stress. In addition, the MT application induced a 978.12%, 33.54%, or 30.59% increase in endogenous MT, indole acetic acid, or gibberellic acid content under osmotic stress but did not affect the accumulation of abscisic acid. These findings suggest that an optimal concentration of MT (100 μmol·L−1) could relieve osmotic stress via improvement in osmotic adjustment, the enzymatic antioxidant defense system, and endogenous hormonal balance, thereby contributing to enhanced photosynthetic functions and growth of oat seedlings under water-limited conditions.

Solar-driven photocatalytic nitrogen fixation on transition metal-doped covalent organic frameworks: First-principles study

Designing highly efficient single-atom catalysts for converting nitrogen into ammonia under ambient temperature conditions holds significant importance. Current research predominantly focuses on electrocatalytic nitrogen fixation, but compared to that, photocatalytic nitrogen fixation requires only sunlight as an energy source, making it more environmentally friendly and cost-effective. Developing efficient nitrogen reduction reaction (NRR) photocatalysts presents a promising yet highly challenging task. Two-dimensional (2D) covalent organic frameworks (COFs) have garnered interest because of their elevated surface area and regular pore structure. This study employs density functional theory calculations to investigate the potential of NRR photocatalysts using the 2D COF TMT-TFPT-COF (TT-COF) supported with 18 different transition metal atoms (TM = Rh, Nb, Os, Mo, Ru, Pt, Ni, Co, V, Cu, Fe, Re, W, Cr, Ta, Mn, Pd, Ti). Through a four-step selection process, the most promising photocatalyst is identified. The results indicate that a single Re atom loaded onto TT-COF (Re@TT-COF) displays the optimal nitrogen fixation performance, demonstrating excellent catalytic activity and selectivity with a limiting potential of only −0.30 V. Furthermore, its good light absorption efficiency, suitable band edge position, and significant photo-generated electron potential enable spontaneous nitrogen fixation. Our study provides useful guidance for the rational design of COF-based NRR photocatalysts with high activity, stability, and selectivity.

Carbon Dots for Anti‐Corrosion

AbstractCarbon dots (CDs) have garnered extensive attention owing to their excellent biocompatibility, elevated specific surface area, and facile functionalization, as well as their diverse methods of preparation. In recent times, CDs have been applied for anti‐corrosion and obtained some significant results. In this work, the preparation methods of CDs are first briefly introduced, and the relative merits of different approaches are highlighted. Subsequently, the application of CDs in the realm of corrosion inhibitors is discussed, and the corrosion inhibition effects and mechanism of nitrogen‐doped CDs, nitrogen and sulfur‐co‐doped CDs, as well as CDs functionalized with other elements and nitrogen‐co‐doped are summarized. Finally, the application of CDs and functionalized CD‐modified coatings for anti‐corrosion and their protective mechanism is analyzed in detail. This review summarizes recent progress in research related to CDs and heteroatom‐doped CDs in anti‐corrosion applications and anticipates the prospects and applications of CDs in corrosion protection. With their unique properties and versatile applications, CDs are expected to assume a progressively pivotal role in the advancement of cutting‐edge corrosion protection technologies.

Interconnectivity can be as important as habitat type in explaining carbon stocks in the coastal lagoons of arid regions

Coastal blue carbon ecosystems, typically comprising interconnected habitat mosaics, are globally important pathways of carbon sequestration and play a significant role in climate change regulation and mitigation. Current coastal management strategies often rely on simplified regional carbon stock estimates, that overlook the geographical variability and intricate ecological dynamics within these ecosystems. This study adopts a seascape ecology approach to evaluate the role of multiple seascape characteristics on carbon storage in two arid region coastal lagoons. We show that seascape location is the most influential driver of carbon stocks. Additionally, carbon isotopic variability, a proxy for connectivity, can be as influential as habitat type, particularly in the UAQ lagoon. This challenges the conventional reliance on data from individual habitat types (e.g., seagrass, mangrove, or tidal marsh) and highlights the context-dependency of carbon stocks. Moreover, the specific characteristics driving carbon stocks vary between seascapes: in Khor Faridah, connectivity to seagrass and mangrove habitats is crucial, while in the UAQ lagoon, sheltered and elevated areas are more influential. Our findings suggest that the interconnectivity between different habitat types, such as mangroves and saltmarshes, significantly enhances carbon storage. This is especially pronounced in large, sheltered mangrove habitat types within upper intertidal zones. Notably, small patches of mangroves, up to 10 ha, are associated with an approximate 10 % increase in carbon stocks. These results underscore the need for a more holistic, context-specific approach to designing nature-based solutions for coastal management and ecosystem restoration. By considering the specific characteristics and connectivity of seascape mosaics, we can more effectively enhance carbon stock potential in coastal ecosystems. This study contributes to a deeper spatially explicit understanding of the complex factors influencing carbon stocks in blue carbon ecosystems, highlighting the importance of tailored management strategies that reflect the unique ecological patterns of each seascape.

Selective catalytic reduction of NOx by NH3 at low temperature over Mn0.5Zr(0.5-x)Fex catalyst with different Fe/Zr ratios

ABSTRACT Through a basic co-precipitation technique, a series of Mn0.5Zr(0.5-x)Fex ternary oxide catalysts with different Fe/Zr ratios have been prepared and applied to the selective catalytic reduction of NOx. The results of catalytic activity test show that the Mn0.5Zr0.2Fe0.3 catalyst with a molar ratio of Fe/Zr of 3:2 has the most effective denitrification activity at low temperature and displays considerable tolerance to SO2 and H2O. The Mn0.5Zr0.2Fe0.3 catalyst exhibits a combination of physical and chemical attributes, including an elevated specific surface area and a homogeneously distributed active component, which collectively furnish additional points of interaction for the reacting gases, thus improving the catalytic performance. In addition, the high Mn4+/Mnn+ and Fe2+/Fen+ ratios, strong redox capacity, and more acidic sites on the surface of the catalyst also have positive effects on its denitrification performance. Meanwhile, the reaction process on Mn0.5Zr0.2Fe0.3 catalyst is driven by the Langmuir-Hinshelwood (L-H) and Eley-Rideal (E-R) mechanisms. This study provides an important reference for the design of Mn-based catalysts with high denitration performance and excellent resistance to SO2 and H2O.

Assessing population status and influencing factors of alpine musk deer in patchy habitats: Implications for conservation strategies

Musk deer (Moschus spp.) are widely known for its musk and are globally endangered as a result of poaching, habitat loss, and fragmentation. To facilitate restoration of the alpine musk deer (M. chrysogaster) in existing areas, reliable estimates of population size and influencing factors are essential to assess effectiveness of conservation interventions, particularly for isolated musk deer populations in patches. In this paper, we used line transect and camera trap data collected from 2020 to 2022 in the Helan mountains to assess the population status and characterized the influencing factors of alpine musk deer. Our findings indicate that musk deer are patchily distributed in three areas of high elevation, with the population limited to less than 200 individuals, remaining below historic levels (compared to 1995). There was a significant positive correlation between the role of sympatric species on musk deer, with red fox (Vulpes vulpes), badger (Meles meles) and blue eared-pheasant (Crossoptilon auritum) having a significant effect on the out-modeled pathway. Variable but insignificant effects of anthropogenic activities were observed across all species categories, which could be due to mutual adaptation over time. Our results imply that the recovery of sensitive population in island-like habitats remains challenging and may be exacerbated by limited environment and resources. Our study underscores the necessity of establishing ecological corridors to enhance habitat connectivity for alpine musk deer, undertaking conservation genetics research on isolated populations, controlling stray dogs to maintain interspecific balance, and implementing electronic fencing to mitigate human disturbance and resource competition. This study provides basic information for understanding the population status of alpine musk deer and offers insights for conservation efforts.

Efficient utilization of lignin heterogeneity: Employing a simple approach to modulate the structure-effect relationship of lignin microspheres for its high-quality applications in supercapacitors

Lignin, an abundant, sustainable, and cost-effective biomass material, is recognized for its high carbon content, making it an ideal candidate for supercapacitors electrode. However, the inhomogeneity of lignin and the amorphous structure of lignin-derived carbon limit its application in energy storage. To effectively address the aforementioned issues, this study initially fractionated alkali lignin (AL) using a green γ-valerolactone/water system to obtain two fractions (L1 and L2) with distinct molecular weights and phenolic hydroxyl contents. The aim of this initiative was to reduce the heterogeneity of the lignin. Subsequently, three groups of lignin microspheres (LMS-AL, LMS-L1 and LMS-L2) with different morphologies were prepared from AL, L1, and L2 using an industrially proven spray-drying technique. This initiative significantly increased the specific surface area of lignin. Ultimately, lignin microspheres were carbonized to prepare carbon microspheres (LMSC-AL, LMSC-L1 and LMSC-L2) that could be used as supercapacitor electrodes. Notably, LMSC-L1 demonstrated superior electrochemical performance, with a specific capacitance of 200 F g−1 at a current density of 1 A g−1, and retaining 93.34 % capacitance after 15,000 charge/discharge cycles. The excellent electrochemical performance of LMSC-L1 is attributed to its elevated specific surface area (388.1 m2 g−1) and substantial porosity (0.238 cm3 g−1). This study also explored practical application, with LMSC-L1 successfully powering LED lights and calculators. Through this research, we have developed a simple method is proposed to modulate the structure of lignin microspheres by leveraging the heterogeneity of lignin itself. Furthermore, we systematically investigated the structure-effect relationship of lignin microspheres and the electrochemical properties of their carbonized microspheres. This work lays a foundational framework for the efficient utilization of lignin in energy storge applications.