Variations In Carbon Content Research Articles

Fracture resistance of the deposited metal under dynamic and cyclic loading

Analyses of experimental data are presented that enable the fracture resistance assessment of dynamically and cyclically loaded materials used for the manufacture and surfacing of rollers in continuous casting machines for beam blanks and crimping mill rollers. It has been noted that steels for manufacturing and surfacing of crimping rolls with different carbon content and alloying elements, differ in the determination fraction of the crack nucleation work in the integral value of the impact strength. The value of that fraction is much higher for corrosion-resistant steels of the Cr13 type which are also distinguished by high fracture resistance to cyclic loading. It is shown that the properties of these steels make it possible, along with the use of CCM rollers for surfacing, to recommend them for hardening the rollers in crimping mills. The possibility of an additional increase in the efficiency of the crimping rolls by eliminating uneven wear along the length of the barrel by surfacing a layer of Cr13 steel with a variable carbon content (0.10-0.25 %) is considered.

Characteristics and Drivers of Soil Carbon, Nitrogen, and Phosphorus Ecological Stoichiometry at the Heavy Degradation Stage of the Alpine Meadow

An in-depth understanding of the soil nutrient status and balance relationship can help the effective recovery and management of alpine degraded meadows. In order to study the balance relationship among soil carbon, nitrogen, and phosphorus nutrients during the heavy degradation stage of meadows, field sampling and investigation, indoor analysis, and mathematical statistics were used to explore the characteristics and driving factors of changes in soil carbon, nitrogen, and phosphorus content, storage, and ecological stoichiometry during the heavy degradation stage of alpine meadows in the Sanjiangyuan region. The results showed that in the heavy degradation stage, miscellaneous grass plants occupied absolute dominance, soil C∶N∶P was approximately 32.83∶3.87∶0.67, and there was certain nitrogen limitation. The coefficients of variation of soil carbon, nitrogen, and phosphorus content were in the following order： organic carbon （1.09） > total nitrogen （0.63） > total phosphorus （0.29）. The organic carbon content and the carbon and nitrogen ratio showed a significant linear decreasing trend with the increase in the grassland degradation index （GDI）, while the total phosphorus content and organic carbon storage showed a significant non-linear change, in which the total phosphorus content showed a significant gentle U-shaped distribution, and the organic carbon storage decreased more gently at the beginning of the heavy degradation stage and then decreased sharply when the GDI was 57.9. The results of Mantel correlation analysis showed that the soil carbon to nitrogen ratio, carbon to phosphorus ratio, and nitrogen to phosphorus ratio showed significant correlation with organic carbon content and storage and total nitrogen storage. The results of structural equation modeling indicated that soil water content had direct effects as well as indirect through vegetation factors, soil carbon, nitrogen, and phosphorus ecological stoichiometry ratios, and soil water content and vegetation factors （height, cover, and biomass） were key environmental factors affecting soil ecological stoichiometry. The research results can provide scientific basis and practical guidance for the restoration of heavily degraded grassland in alpine meadows.

Precipitation changes during the last glacial period in the Ili Basin, northern Central Asia, as inferred from the records of loess dolomite

Understanding the climatic evolution in Central Asia (CA) and its drivers is crucial for informed decision-making and predicting global changes due to its significant contribution as a global dust source. Unfortunately, our current understanding of the pre-Holocene precipitation patterns in CA is lacking due to the limited availability of reliable proxy indicators, and our knowledge of future precipitation projections in the region, based on paleoclimatic dynamics, is also quite limited. In this study, we analyzed variations in carbonate and dolomite contents of a loess section in the Ili Basin, northern CA, to reveal precipitation changes during the last glacial period. The results showed that changes in carbonate minerals were mainly influenced by the source material supply, driven by reduced precipitation and eluviation during glacial period. We thereby established a precipitation index by removing the influence of provenance signals from the dolomite records. The index indicated lower precipitation during mid-marine isotope stage (MIS) 3 compared to MIS2, likely due to meridional shifts and intensity changes of the westerlies caused by changes in precession and obliquity, with precession playing a major role. Through the comparison of the precipitation index with the δ18O records of the Greenland ice core on a millennial timescale, it was observed that the precipitation in northern CA exhibited a positive correlation with the North Atlantic Oscillation (NAO) mode due to migration of the westerlies. By leveraging our understanding of orbital- and millennial-scale precipitation patterns, we utilized the random forest (RF) regression model and the autoregressive integrated moving average model to forecast precipitation changes for the upcoming 5000–10,000 years. The results indicated a variable pattern marked by a general upward trend, suggesting the possibility of favorable development of agricultural-based economies in the Ili River Valley. People should realize that some integrated measures are designed to improve resilience of agricultural sector in the region and enhance its capacity to adapt to challenges posed by climate change. However, more extensive research is necessary to verify these results through thorough examination and comparisons of loess sections in our research location.

Effect of varying carbon content on microstructure and mechanical properties of (Ti,Ta,Nb,Zr,Mo)C-Co high-entropy ceramic based cermets

The effects of carbon content on microstructure and mechanical properties of the (TiTaNbZrMo)C-Co cermets were investigated in details. Uniform high-entropy carbide powders with different carbon contents were obtained through carbothermal reduction and mixed with a Co binder phase via ball milling for fabricating cermets at the elevated temperature. The increased carbon content makes the hardness of cermets initially rose and then decreased, while the fracture toughness demonstrates an overall decline. Among all high-entropy ceramic based cermets, (TiTaNbZrMo)C0.9-Co cermet (C1) exhibited the optimal combination of hardness and fracture toughness properties, with a Vickers hardness (HV30) of 15.83 GPa and a fracture toughness of 7.74 MPa m1/2. Furthermore, the presence of graphite phases accompanied by the excess carbon content could enhance the wear resistance of cermets. (Ti,Ta,Nb,Zr,Mo)C-Co high-entropy ceramic based cermets have potential applications in the fields of cutting tools and wear-resistant components.

More sensitive microbial responses to the interactive effects of warming and altered precipitation in subsoil than topsoil of an alpine grassland ecosystem.

Subsoil is a large organic carbon reservoir, storing more than half of the total soil organic carbon (SOC) globally. Conventionally, subsoil is assumed to not be susceptible to climate change, but recent studies document that climate change could significantly alter subsoil carbon cycling. However, little is known about subsoil microbial responses to the interactive effects of climate warming and altered precipitation. Here, we investigated carbon cycling and associated microbial responses in both subsoil (30-40 cm) and topsoil (0-10 cm) in a Tibetan alpine grassland over 4 years of warming and altered precipitation. Compared to the unchanged topsoil carbon (β = .55, p = .587), subsoil carbon exhibited a stronger response to the interactive effect of warming and altered precipitation (β = 2.04, p = .021), that is, warming decreased subsoil carbon content by 28.20% under decreased precipitation while warming increased subsoil carbon content by 18.02% under increased precipitation.Furthermore, 512 metagenome-assembled genomes (MAGs) were recovered, including representatives of phyla with poor genomic representation. Compared to only one changed topsoil MAG, 16 subsoil MAGs were significantly affected by altered precipitation, and 5 subsoil MAGs were significantly affected by the interactive effect of warming and precipitation. More than twice as many populations whose MAG abundances correlated significantly with the variations of carbon content, components and fluxes were observed in the subsoil than topsoil, suggesting their potential contribution in mediating subsoil carbon cycling. Collectively, our findings highlight the more sensitive responses of specific microbial lineages to the interactive effects of warming and altered precipitation in the subsoil than topsoil, and provide key information for predicting subsoil carbon cycling under future climate change scenarios.

Archaeological textiles preserved by copper mineralization

The mineralization mechanism responsible for the fossilization of archaeological textiles in close proximity to metal artifacts presents a sophisticated preservation process at both macro and micro levels. This study examines archaeological textiles dating from 2200 BC to AD 1900, sourced from three distinct archaeological sites. The focus is on understanding the microstructural degradation of fibers within a specific burial environment and the preservation achieved through mineralization. These archaeological fibers of archaeological textiles exhibit morphological preservation in the immediate vicinity of copper-based objects. Utilizing tools such as a digital camera, scanning electron microscopy with energy dispersive spectroscopy (SEM–EDS), high-resolution synchrotron-based microtomography (μCT), and enzyme-linked immunosorbent assay (ELISA), we examined fiber morphology, conducted elemental analysis, identified fiber types, and analyzed fiber characteristics. Our findings reveal the presence of smooth-surfaced wools and silks, fibers covered with calculi, and fiber impressions—all subjected to mineralization. These mineralized fibers can be categorized into three distinct stages of mineralization, each exhibiting varying carbon content. We inferred a correlation between mineralization rate and carbon content while also identifying mineralization density distribution on these textiles. Lastly, this study provides insights into the preservation states of textiles across three different mineralization stages, enriching our understanding of the deterioration of organic archaeological material.

Evaluation of sustainability of fabrication process and characterization studies of activated carbon nanocatalyst from waste chestnut peels

This study uses waste chestnut peels to synthesize low-cost activated carbon-based catalysts through pyrolysis and calcination, investing distinct structural and compositional variations for sustianble application in manufacturing innovation and allied industries. The X-ray diffraction (XRD) analysis indicated sharp crystalline peaks in the calcinated product, contrasting with the amorphous nature of carbon material with some partially crystalline and distorted graphitic phases of the pyrolyzed product. Fourier-transform Infrared spectroscopy (FT-IR) analysis shows the presence of various functional groups such as O–H, C–O, C–H, CO, and CC. The analysis made through the scanning electron microscope (SEM) and transmission electron microscope (TEM) depicted a packed and agglomerated structure with different irregular particle shapes in the calcined carbon, while the sample prepared through pyrolysis exhibited a network-like structure with some interconnected voids. Energy dispersive X-ray (EDX) analysis showed varying carbon content which is found to be 47.41 % in the case of the calcinated sample and 99.7 % in the product prepared through pyrolysis. The calcined carbon exhibited a band gap of 4 eV, while the pyrolyzed carbon showed a higher band gap of 4.8 eV. In addition, the catalyst prepared through the calcination process exhibited significantly higher luminance intensity than that produced through pyrolysis, while both samples showed an excitation-dependent emission property. This work presents two simple methods for synthesizing nanocarbon-based catalysts using waste lignocellulosic biomass. In addition, the optical properties of the resulting nanocarbons suggest that they can be further explored for their applications as catalysts or biosensing agents.

Investigation of the growth kinetics of Streptococcus mutans bacteria on Zr-C coating surfaces deposited on 316L stainless steel substrates

The conducted research aims to describe the kinetics of Streptococcus mutans bacteria growth on the surface of Zr-C coatings with varying carbon content deposited on 316L medical-grade stainless steel substrates.The coatings were deposited using the MS PVD (Magnetron Sputtering Physical Vapour Deposition) technique at a constant temperature of 400C. Varying carbon contents in the coatings were achieved by changing the flow rate of acetylene during the process. The dynamics of bacteria growth cultivated at 37C were examined on the surface of the coatings for incubation times ranging from 0 to 72 hours. Generalised logistic functions were utilised for the mathematical description of the obtained results.The produced coatings exhibited varying carbon content, determining the structural composition ranging from a mixture of metallic Zr and ZrC through stoichiometric zirconium carbide to nanocrystalline grains of ZrC in an amorphous carbon matrix. The obtained results unequivocally demonstrate that in the case of ZrC coatings, the carbon content influences both the bacterial growth rate during the proliferation phase and the final population of bacteria.In the conducted research on bacterial population dynamics, only a single strain of Streptococcus mutans was considered, and the mathematical description was limited to reaching a pseudo-steady state by the population.The proposed model can successfully be adapted to describe the dynamics of other individual strains of bacteria dwelling on metallic surfaces as well as coatings.The proposed model can serve as a tool for studying, among other things, inflexion points of logistic curves, which are considered as the boundary between the dominance of anabolic and catabolic processes in the bacterial population.

Patterns and drivers of organic carbon in hydromorphic soils across inland aquatic-terrestrial ecotones at the global scale

The aquatic-terrestrial ecotones of inland waters, including rivers, lakes, and reservoirs, are subject to occasional, recurrent, or even permanent flooding and play a vital role in the carbon cycles of aquatic ecosystems. However, the patterns and drivers of soil organic carbon in aquatic-terrestrial ecosystems have not been clearly documented on a global scale. To address this knowledge gap, we constructed a database of organic carbon content of 1970 globally distributed aquatic-terrestrial ecotone soils and utilized a random forest model to measure the primary drivers at global scale. We found that the average soil organic carbon content was 26, 33, and 18 g kg−1, and the mean soil organic carbon stock was 24.95, 22.38, and 30.66 t ha−1 for the aquatic-terrestrial ecotones of rivers, lakes, and reservoirs, respectively. Notably, the soil organic carbon content in lake ecotones was significantly higher than in river and reservoir ecotones. However, reservoir ecotones stored the highest soil organic carbon compared to lake and river ecotones. The random forest model explained 52 %, 49 %, 58 %, and 28 % variations of soil organic carbon content across all sites, river, lake, and reservoir ecotones, respectively. Soil physiochemical properties exert more pronounced effects across all ecotone types than climate factors when predicting soil organic carbon in global aquatic-terrestrial ecotones. However, it is noteworthy that the primary drivers of soil organic carbon content vary according to ecotone type. For river and lake ecotones, nitrogen content emerges as the dominant factor regulating organic carbon content. Conversely, in reservoir ecotones, pH stands out as the primary driver for soil organic carbon content. Beyond nitrogen content and pH, the composition of silt and clay also proves pivotal in predicting soil organic carbon in aquatic-terrestrial ecotones. These findings underscore the critical determinants of soil organic carbon accumulation in global inland aquatic-terrestrial ecotones.

Ensemble learning algorithms to elucidate the core microbiome's impact on carbon content and degradation properties at the soil aggregate level

Soil aggregates are crucial for soil organic carbon (OC) accumulation. This study, utilizing a 32-year fertilization experiment, investigates whether the core microbiome can elucidate variations in carbon content and decomposition across different aggregate sizes more effectively than broader bacterial and fungal community analyses. Employing ensemble learning algorithms that integrate machine learning with network inference, we found that the core microbiome accounts for an average increase of 26 % and 20 % in the explained variance of PCoA and Adonis analyses, respectively, in response to fertilization. Compared to the control, inorganic and organic fertilizers decreased the decomposition index (DDI) by 31 % and 38 %, respectively. The fungal core microbiome predominantly influenced OC content and DDI in larger macroaggregates (>2000 μm), explaining over 35 % of the variance, while the bacterial core microbiome had a lesser impact, explaining <30 %. Conversely, in smaller aggregates (<2000 μm), the bacterial core microbiome significantly influenced DDI (R2 > 0.2), and the fungal core microbiome more strongly affected OC content (R2 > 0.3). Mantel tests showed that pH is the most significant environmental factor affecting core microbiome composition across all aggregate sizes (Mantel's r > 0.8, P < 0.01). Linear correlation analysis further confirmed that the core microbiome's community structure could accurately predict OC content and DDI in aggregates (R2 > 0.8, P < 0.05). Overall, our findings suggested that the core microbiome provides deeper insights into the variability of aggregate organic carbon content and decomposition, with the bacterial core microbiome playing a particularly pivotal role within the soil aggregates.

Enhanced tribological behavior and corrosion resistance in AlSiC-based coatings through varied carbon content

A series of AlSiC-based nanocomposite coatings with varying carbon concentrations were fabricated by filtered cathodic vacuum arc (FCVA) technology. These coatings featured an amorphous matrix with embedded Al4Si3C6 nanocrystals. With the increase in carbon content, the proportion of amorphous structure within the structure grew, which was accompanied by a rise in sp3 hybridized carbon bonds. This compositional change led to a significant enhancement in hardness and toughness. Notably, the AlSiC coating deposited at a flow rate of 50 sccm displayed exceptional mechanical properties, including a high hardness of approximately 23.2 GPa, toughness indices of H/E = 0.096 and H3/E2 = 0.216 GPa, a low friction coefficient around 0.18, a wear rate as low as ∼1.09 × 10−5 mm3 N−1 m−1, and a corrosion current density of approximately 1.08 × 10−9 A/cm2. The coating's superior tribological characteristics and corrosion resistance can be attributed to two main factors. The enhanced hardness and toughness indices (H/E and H3/E2) contributed to its improved deformability, which is essential for wear resistance. Secondly, the presence of a graphite layer formed during friction provided self-lubrication, further reducing wear. Additionally, the chemical inertness of both the amorphous SiC and the amorphous carbon phases within the nanocomposite structure significantly bolstered the coating's resistance to corrosion. The AlSiC nanocomposite coatings deposited by FCVA exhibit outstanding mechanical properties, tribological performance, and corrosion resistance, making them highly suitable for applications in environments where wear and corrosion are significant concerns.

Enhanced mechanical properties of dispersed carbide-strengthened CrFeNi-based medium entropy alloys prepared via powder metallurgy

In this study, a set of CrFeNi -based medium-entropy alloys (MEAs) with varying carbon contents were prepared by spark plasm sintering (SPS) using atomized alloy powders as raw material. The microstructures of powders and as-sintered alloys were characterized using ECCI and EBSD. The mechanical properties of as-sintered alloys were tested and the strengthening mechanical were discussed. The results showed that the microstructures of the CrFeNi gas atomized powder and sintered alloy were both single FCC phase in an equiaxed state. However, the matrix grains of powder with carbon addition were mostly dendritic, and few eutectic carbides could be observed between matrix grains. Compared with the CrFeNi MEA, the addition of 8 at. % C led to an increase in the yield strength and tensile strength from 395 MPa to 630 MPa–590 MPa and 990 MPa, respectively. Orowan strengthening and grain refinement resulting micro/nano carbides are responsible for the improvement in mechanical properties.

Effect of carbon content on microstructure, mechanical properties and tribological behavior of HfZrC coating

The HfZrC coatings containing varying carbon contents were fabricated by magnetron sputtering method. The relationship between coating composition and mechanical properties as well as tribological behavior was studied. The coatings containing lower carbon are mainly composed of (Hf,Zr)C carbide, less metal and amorphous graphite-like carbon (GLC). The increasing carbon contents significantly favored the formation of (Hf,Zr)C carbide, leading to the enhanced hardness and elastic modulus. Excessive carbon increased the GLC content, thus degrading the two aforementioned performances. During the friction process, the low-carbon coating fractured in a short friction duration due to the remarkable shear stress. The abrasive wear dominated the following friction process, resulting in severe wear loss of TC4 substrate. Comparatively, the lubricant GLC in high-carbon coating alleviated the coating fracture. Hence, the wear rate of high-carbon coatings was decreased significantly by inhibiting the abrasive wear.

Biocrusts enhance soil structural stability during freeze-thaw cycles and improve soil erosion resistance in cold-winter drylands

Seasonally frozen soils are extensively distributed in drylands at middle- and high-latitude regions across the earth and experience intensive freeze-thaw cycles during cold winters. Cyanobacterial and moss biocrusts are critical living skins that cover a large portion of cold-winter drylands and, thus, have potential to regulate soil structure and function within frozen periods. Yet, the biocrust effect on soil structural stability during freezing and thawing and its underlying influencing factors have remained unanswered. Here, we conducted freezing and thawing simulations to elucidate the responses of soil structural stability to cyanobacteria- and moss-biocrust cover under different cycles of freeze-thaw (0–40 cycles) and initial water contents (0.03–0.20 cm3 cm−3). Our findings unveiled that the structural stability of bare soil, cyanobacterial biocrusts, and moss biocrusts decreased by 38.4%, 28.9%, and 24.1%, respectively, as a result of increasing freeze-thaw cycles and initial water content. However, as compared with bare soil, biocrust cover significantly mitigated the adverse impacts of freezing and thawing on soil structural stability. Specifically, biocrusts reduced the relative variation of soil particle-size distribution, porosity, and organic carbon content by 68.9%, 41.1%, and 32.1%, respectively, during increasing freeze-thaw cycles. Meanwhile, the relative variation of these properties caused by increasing initial water content during freezing and thawing was reduced by 39.4% due to the biocrust cover. As the consequences of such changes, biocrusts ultimately reduced the relative degradation of structural distance, aggregate stability, and erodibility by 39.4% in increasing freeze-thaw cycles and by 43.6% in increasing initial water content. This clearly demonstrated the biocrust contributions to enhancing soil structural stability and improving soil erosion resistance during freezing and thawing. Our study highlights the fundamental role of biocrusts in intervening soil structural degradations, caused by freeze-thaw cycles, and in serving as an imperative consideration during frozen periods in cold-winter drylands.

Response of carbon, nitrogen, and phosphorus in leaves of different life forms to altitude and soil factors in Tianshan wild fruit forest

IntroductionThe ecological stoichiometric ratio of carbon, nitrogen, and phosphorus is an important index to understand the utilization and distribution of plant nutrients.MethodTo explore how leaf carbon, nitrogen, and phosphorus contents, along with the stoichiometric ratio of different life forms of plants, respond to variations in altitude and soil physical and chemical properties, leaves and soil samples were collected from different life forms of plants at different altitudes (1,100~1,700 m) within the Guozigou region of the forest. Subsequently, the contents and ratios of carbon, nitrogen, and phosphorus in the leaves, as well as the physicochemical properties of the soil, were determined.ResultsThe results showed the following: (1) The three life forms of plants in the study area showed that the coefficient of variation of leaf carbon content was the smallest and the distribution was the most stable, while the coefficient of variation of carbon–nitrogen ratio was the largest. (2) Altitude had a significant effect on the carbon, nitrogen, and phosphorus contents of different life form of plants, among which the leaf nitrogen content of trees, shrubs, and herbs increased significantly with altitude (p &amp;lt; 0.01), the leaf phosphorus content of trees increased significantly with altitude (p &amp;lt; 0.01), and the leaf C:N of the three life form of plants decreased significantly with altitude (p &amp;lt; 0.01). The C:P of the arbor decreased significantly with altitude (p &amp;lt; 0.05), and the N:P of shrub and herb leaves increased significantly with altitude (p &amp;lt; 0.01). (3) Soil organic carbon and soil moisture content were the main environmental factors affecting the changes of carbon, nitrogen, and phosphorus in leaves of arbors, and nitrate nitrogen was the main environmental factor affecting the changes of carbon, nitrogen, and phosphorus in leaves of shrubs. Available phosphorus affected the changes of carbon, nitrogen, and phosphorus in the leaves of herbaceous plants.DiscussionThe results provide new insights into community-level biogeographical patterns and potential factors of leaf stoichiometry among plant life forms.

Variation of carbon, nitrogen and phosphorus content in fungi reflects their ecology and phylogeny.

Fungi are an integral part of the nitrogen and phosphorus cycling in trophic networks, as they participate in biomass decomposition and facilitate plant nutrition through root symbioses. Nutrient content varies considerably between the main fungal habitats, such as soil, plant litter or decomposing dead wood, but there are also large differences within habitats. While some soils are heavily loaded with N, others are limited by N or P. One way in which nutrient availability can be reflected in fungi is their content in biomass. In this study, we determined the C, N, and P content (in dry mass) of fruiting bodies of 214 fungal species to inspect how phylogeny and membership in ecological guilds (soil saprotrophs, wood saprotrophs, and ectomycorrhizal fungi) affect the nutrient content of fungal biomass. The C content of fruiting bodies (415 ± 25 mg g-1) showed little variation (324-494 mg g-1), while the range of N (46 ± 20 mg g-1) and P (5.5 ± 3.0 mg g-1) contents was within one order of magnitude (8-103 mg g-1 and 1.0-18.9 mg g-1, respectively). Importantly, the N and P contents were significantly higher in the biomass of soil saprotrophic fungi compared to wood saprotrophic and ectomycorrhizal fungi. While the average C/N ratio in fungal biomass was 11.2, values exceeding 40 were recorded for some fungi living on dead wood, typically characterized by low N content. The N and P content of fungal mycelium also showed a significant phylogenetic signal, with differences in nutrient content being relatively low within species and genera of fungi. A strong correlation was found between N and P content in fungal biomass, while the correlation of N content and the N-containing fungal cell wall biopolymer-chitin showed only weak significance. The content of macronutrients in fungal biomass is influenced by the fungal life style and nutrient availability and is also limited by phylogeny.

Study on Leaf Morphological and Stoichiometric Traits of Cunninghamia lanceolata Based on Different Provenances

The purpose of this study is to look into the differences in leaf functional traits between Cunninghamia lanceolata from different provenances, as well as to expose the response characteristics of leaf morphological and stoichiometric traits of Cunninghamia lanceolata from different provenances to diverse the environment of provenances. In this study, we chose 30 Cunninghamia lanceolata from different provenances as the research object and analyze the differences in leaf morphological and stoichiometric traits of Cunninghamia lanceolata from different provenances, the relationships among leaf functional traits, and the relationships between leaf functional traits and environmental factors of provenances. The results showed that the coefficient of variation of leaf morphological traits was 15.31% to 22.86%，and the coefficient of variation of stoichiometry provenances was 3.19% to 26.05%. The coefficient of variation of leaf carbon content was relatively small，indicating that carbon is the most stable element in the Cunninghamia lanceolata. And significant correlations are observed among different leaf functional traits. Using redundancy analysis to explore the relationship between leaf functional traits and environmental factors of provenances, it was found that the genetic effects of environmental factors explained 43.19% of the heterogeneity in leaf functional traits of Cunninghamia lanceolata. As a result, studying the variation of leaf functional traits of Cunninghamia lanceolata from different provenances, as well as how they correlate with environmental factors in provenances, is critical for understanding and predicting the responses and adaptations of Cunninghamia lanceolata from different provenances in the backdrop of global changes in the environment, and it additionally serves as a scientific basis for the sustainable development of Cunninghamia lanceolata and the selection of excellent Cunninghamia lanceolata provenances. Meanwhile, it makes scientific recommendations for China to do research on the sustainable development and productivity enhancement of cedar plantation forests.

Patterns and driving factors of functional traits of desert species with different elevational distributions in the Tibetan Plateau and adjacent areas

Variations in functional traits serve as measures of plants’ ability to adapt to environment. Exploring the patterns of functional traits of desert plants along elevational gradients is helpful to understand the responses and adaptation strategies of species to changing environments. However, it is unknown whether the relationship between functional traits and elevation is affected by differences in the species’ elevational distributions (elevation preference and species’ range). Importantly, most researches have concerned with differences in mean trait values and ignored intraspecific trait variation. Here, we measured functional traits of desert plants along a wide elevational gradient in the Tibetan Plateau and adjacent areas and explored functional trait patterns over elevation in species with different elevational distributions. We decomposed trait variation and further investigated characterizations of intraspecific variation. Ultimately, the main drivers of trait variation were identified using redundancy analysis. We found that species’ elevational distributions significantly influenced the relationship of functional traits such as plant height, leaf dry matter content, leaf thickness, leaf nitrogen and carbon content with elevation. Species with a lower elevational preference showed greater trait variation than species with a higher elevational preference, suggesting that species that prefer high elevation are more conservative facing environmental changes. We provide evidence that interspecific trait variation in leaf thickness and leaf carbon content decreased with increasing species’ range, indicating that increased variations in resistance traits within species make greater responsiveness to environmental changes, enabling species a wider range. Elevation, temperature and precipitation were the main drivers of trait variation in species with a low elevational preference, while the effect of precipitation on trait variation in species with a high elevational preference was not significant. This study sheds new insights on how plants with different elevational distributions regulate their ecological strategies to cope with changing environments.

In-situ online detection of carbon during combustion via laser-induced breakdown spectroscopy

The combustion of fossil fuels is primarily responsible for disrupting the carbon cycle equilibrium by releasing greenhouse gases (GHGs). Therefore, detecting GHG emissions from fossil fuels is extremely important. In this study, utilizing laser-induced breakdown spectroscopy (LIBS), a new method for real-time in-situ detection of carbon fluctuations during combustion has been developed. The combustion of fossil fuels is emulated through the controlled burning of candles within a confined area, and the elemental content of the surrounding air during this process is analyzed. Fluctuations in the intensity of CN spectral lines were tracked to reveal changes in carbon concentration. The backpropagation neural network (BPNN) is used to identify and verify local air with different carbon concentrations, and the predictions are accurate. In conclusion, the integration of BPNN and LIBS for the purpose of identifying variations in carbon content during combustion provides an effective method for environmental management.

More microscopic interfacial segregation slowers macroscopic grain growth: A case in WC-Co cemented carbides

In industrial practice, combining grain growth inhibitors (GGIs) with low carbon content effectively restrains WC grain growth in WC-Co cemented carbides. However, the intricate relationship between carbon content, WC grain microstructure, and GGI impact remains unresolved. This study investigates two WC-Co sample sets, maintaining constant VC inhibitor levels but varying carbon content near upper (HC) and lower (LC) limits. SEM analysis revealed distinct morphologies: HC displayed truncated prism shapes, exposing long basal and prismatic terraces, while LC exhibited a saw-tooth morphology with finer grains. EBSD stereology quantified anisotropic WC grain growth, revealing suppressed growth perpendicular to both basal (HC: 0.51 μm vs. LC: 0.38 μm) and prismatic planes (HC: 0.44 μm vs. LC: 0.37 μm) with decreased carbon content. Atomic-resolution EDS showed higher V solute excess in LC at WC(basal)-Co, WC(prismatic)-Co interfaces, and step corners (HC: 4.6, 0.9, and 4.4 atoms/nm2; LC: 5.5, 0.9, and 7.8 atoms/nm2). Our findings elucidate a clear physical understanding that a low carbon content enhances V atom solubility within liquid cobalt, increasing the thickness of complexions to quad-layer on WC (basal)-Co interfaces and forming V-rich nanoprecipitates at step corners. Those inhibitory effects further limited step flow, resulting in pronounced step bunching and a saw-tooth fine-grained morphology in LC sample. This study highlights that complexions housing more inhibitory solute elements exert a stronger drag effect on grain growth front migration. This approach has the potential for studying grain growth in anisotropic materials, highlighting the importance of constructing experimental complexion diagrams in engineering fine-structured ceramics and metals.