Carbon Ratios Research Articles

Carbon persistence of soils with long‐term biosolids amendments in California agroecosystems

AbstractBiosolids can build soil organic matter, but their ability to increase carbon and nitrogen in persistent fractions in deep soil is not well understood. We aimed to assess the mechanisms that influence soil carbon and nitrogen dynamics at three sites—Sacramento (irrigated, grazed grassland), Solano (rainfed, grazed grassland), and Merced (feed cropping system with alfalfa–corn rotation)—where soils were amended with biosolids for 20 years using density fractionations, organomineral extractions, and correlations between calcium and soil organic carbon at three depths (0–10, 30–50, and 75–100 cm). We found that amended soils had higher carbon and nitrogen content in the free‐ and occluded‐light fractions at all depths relative to the control in the Sacramento and Solano sites; however, the Merced site had a greater relative increase of carbon and nitrogen associated with the heavy fraction. Effect sizes show that biosolids increase carbon and nitrogen content in free‐ and occluded‐light fractions in the surface soil (0–10 cm), and in both light and heavy fractions in the deep soil layer (75–100 cm). Ratios of carbon to iron and aluminum show that chelation is an important mechanism of carbon stabilization in Sacramento and Solano sites throughout the soil profile. No (0–10 cm) to negative (75–100 cm) correlations were observed between calcium and soil carbon in the amended soils in the Merced site. Our results indicate that, while biosolids are typically incorporated at shallow depths, long‐term application of biosolids can increase the amount of free‐ and occluded‐light carbon fractions in deep soil.

Soil temperature and moisture as key controls of phosphorus export in mountain watersheds

Oligotrophic mountain lakes act as sensitive indicators of landscape-scale changes in mountain regions due to their low nutrient concentration and remote, relatively undisturbed watersheds. Recent research shows that phosphorus (P) concentrations are increasing in mountain lakes around the world, creating more mesotrophic states and altering lake ecosystem structure and function. The relative importance of atmospheric deposition and climate-driven changes to local biogeochemistry in driving these shifts is not well established. In this study, we test whether increasing temperatures in watershed soils may be contributing to the observed increases in mountain lake P loading. Specifically, we test whether higher soil temperatures increase P mobilization from mountain soils by accelerating the rate of geochemical weathering and soil organic matter decomposition. We used paired soil incubation (lab) and soil transplant (field) experiments with mountain soils from around the western United States to test the effects of warming on rain-leachable P concentration, soil P mobilization, and soil respiration. Our results show that while higher temperature can increase soil P mobilization, low soil moisture can limit the effects of warming in some situations. Soils with lower bulk densities, higher pH, lower aluminum oxide contents, and lower ratios of carbon to nitrogen had much higher rain-leachable P concentration across all sites and experimental treatments. Together, these results suggest that mountain watersheds with high-P soils and relatively high soil moisture could have the largest increases in P mobilization with warming. Consequently, lakes and streams in such watersheds could become especially susceptible to soil-driven eutrophication as temperatures rise.

Effects of lipid extraction on stable isotope ratios of carbon and nitrogen in muscles of freshwater fish

ABSTRACT The extraction of lipids by the Folch method from the muscles of all the fish studied led to statistically significant differences in the values of δ 15N. At the same time, lipid extraction led to a statistically significant increase in δ 13C in pike and roach, and to a statistically insignificant decrease in δ 13C in perch and bream. Thus, lipid extraction cannot serve as a universal method of sample preparation for the analysis of the isotopic composition of carbon (13C/12C) and nitrogen (15N/14N) in fish muscles. The differences between the δ 13C values in the samples before and after lipid extraction were statistically investigated by different models. It is shown that mathematical correction method models can be used, but the results are depending on the fish types.

Surface acoustic wave spectroscopy for non‐destructive coating and bulk characterization at temperatures up to 600°C enabled by piezoelectric aluminum nitride coated sensor

Surface acoustic wave spectroscopy has been established as non‐destructive and fast method for characterization of mechanical properties of surfaces and bulk materials in both research and industry. The present work shows that by application of a novel and robust aluminum nitride (AlN) coated piezoelectric contact sensor the advantages of the method can be extended from room temperature to at least 600°C. An overview of sensor concepts and applications of the method is discussed first, followed by theoretical and practical considerations for design and coating of a novel temperature stable contact sensor. After fabrication of such a sensor using magnetron sputtering, it was tested in a modified surface acoustic wave spectroscopy setup with an incorporated heating table concerning signal amplitude and frequency range. The AlN coated sensor was found to perform well up to 600°C, with temperature limited by the specification of the heating table. At room temperature, performance was acceptable when compared with a conventional contact sensor using a PVDF piezoelectric foil. Application of the high temperature capabilities of the setup was demonstrated by measuring temperature stability of hydrogen‐free amorphous carbon coatings (a‐C and ta‐C) depending on their sp3 carbon ratio. In another example, high precision temperature dependent measurement of Young's modulus for ultrasonic fatigue test specimen was taken, achieving an accuracy better than 1%. Use of the developed sensor opens up new possibilities in material science for in situ study of temperature depending mechanical properties for coatings and surfaces.

Strontium isotope proxy of sedimentological records reveals uplift and erosion in the Southeastern Neo-Tethys ocean during the late Cretaceous

The mutual interplays between plate tectonic processes, orogenesis and continental uplift, high-flux magmatism, and high sedimentation rates can affect the geochemical signatures and composition of marine sediments. Here, we examine two major disconformities, the Cenomanian–Turonian boundary (CT-ES) and the middle Turonian (mT-ES) exposure surfaces, from the Upper Cretaceous sedimentary successions of the southeastern Neo-Tethys Ocean in the Zagros Basin (Iran). The disconformities are expressed as distinct positive peaks in rubidium (Rb) contents and 87Sr/86Sr isotopic ratios of carbonates. The 87Sr/86Sr values of samples bracketing the disconformities in seven well cores give average age ranges of 94.4–93.6 Ma for the CT-ES and 91–86 Ma for the mT-ES. These ages fall in the timespan of forearc/ophiolite formation through subduction initiation in the Neo-Tethys realm (southern margin of Eurasia), high convergence velocities between Arabia and Eurasia, and blueschist exhumation. All these processes involved buckling of the Neo-Tethyan lithosphere, initiating the Neo-Tethys closure and a high erosion rate on the Eurasian margin. The first two mechanisms exerted considerable compressional forces on the adjacent carbonate platforms, reactivated basement faults, and led to the uplift and erosion of the Arabian Plate, which provided the high contents of Rb and the high 87Sr/86Sr ratios in the carbonates.

Physical Properties, Chemical Components, and Transport Mechanisms of Atmospheric Aerosols Over a Remote Area on the South Slope of the Tibetan Plateau

AbstractThe physicochemical properties and origins of atmospheric aerosols in the Tibetan Plateau (TP) region are a research topic of great interest, but an in‐depth understanding of this topic is challenging, partially due to a lack of intensive in situ observations. Thus, a field campaign was conducted over Yadong, a remote area on the south slope of the TP from June 11 to 31 August 2021. The aerosol loading was low, with a black carbon mass concentration of 147.4 ± 98.4 ng·m−3. Aerosol single‐scattering albedo was low (0.73 ± 0.11 at 550 nm) and increased from 450 to 700 nm wavelength. Organic matter (OM) accounting for 69.6% of the total aerosol mass and relatively high secondary organic carbon ratios, highlighting the importance of secondary formation. An interesting phenomenon observed was that the evolution of aerosols was mainly characterized by diurnal variation, which could not be explained by large‐scale atmospheric processes such as Indian summer monsoon. Instead, it was found that regional mountain‐valley winds between the Himalayas and South Asia transported polluted air masses toward the TP, especially in the afternoon when regional valley wind are expected to be the strongest and the boundary layer in South Asia is deepest. Additionally, daytime local valley wind further elevated these aerosols to higher altitudes on the TP. This paper provides insights into the transport mechanisms of aerosols from South Asia to the TP. These findings are of great importance since aerosols exhibit significant diurnal variations in the TP region.

The Effect of the Ratio of C45 Carbon to Graphene on the Si/C Composite Materials Used as Anode for Lithium-ion Batteries

<p>Due to its high theoretical capacity, Silicon (Si) has shown great potential as an anode material for lithium-ion batteries (LIBs). However, the large volume change of Si during cycling leads to poor cycling stability and low Coulombic efficiency. In this study, we synthesized Si/Carbon C45:Graphene composites using a ball-milling method with a fixed Si content (20%) and investigated the influence of the C45/Gr ratio on the electrochemical performance of the composites. The results showed that carbon C45 networks can provide good conductivity, but tend to break at Si locations, resulting in poor conductivity. However, the addition of graphene helps to reconnect the broken C45 networks, improving the conductivity of the composite. Moreover, the C45 can also act as a protective coating around Si particles, reducing the volume expansion of Si during charging/discharging cycles. The Si/C45:Gr (70:10 wt%) composite exhibits improved electrochemical performance with high capacity (~1660 mAh g<sup>−1</sup> at 0.1 C) and cycling stability (~1370 mAh g<sup>−1</sup> after 100 cycles). This work highlights the effective role of carbon C45 and graphene in Si/C composites for enhancing the performance of Si-based anode materials for LIBs.</p>

Carbon‐cycle perturbations and intensified continental chemical weathering linked to volcanism during the Jenkyns Event in the Ordos Basin

The Jenkyns Event (~183 Ma) represents an exceptional warming period in the Jurassic, which is characterized by intense environmental and climate perturbation. The eruption of the Karoo‐Ferrar Large Igneous Province (K‐F LIP) triggered pronounced carbon isotope negative excursion (N‐CIE) in exogenic carbon reservoirs, global widespread organic carbon burial and extensive ocean anoxia. However, the synchronic coupling relationship between the carbon release, volcanic activity, and intense weathering induced by the K‐F LIP during this period remains poorly understood. In this study, detailed sedimentologic and geochemical studies were conducted on the terrestrial stratigraphy of the Lower Jurassic Fuxian Formation in the Ordos Basin. Three spore‐pollen assemblages have been identified, with the Cyathidites‐Deltoidospora‐Chasmatosporites assemblage suggesting a Pliensbachian age, the Classopollis‐Cycadopites‐Chasmatosporites assemblage indicating an early to middle Toarcian age, and the Cyathidites‐Cycadopites‐Psophosphaera assemblage indicating a late Toarcian age. The lower part of the Classopollis‐Cycadopites‐Chasmatosporites assemblage shows a negative CIE with a magnitude of 2.7‰, accompanied by organic carbon enrichment. Mercury concentrations and Hg/total organic carbon ratios also show peaks during the initial stage of the carbon isotope negative shift, implying a synchrony between volcanic activities and carbon perturbation. Furthermore, the Chemical Index of Alteration value has reached its maximum and the kaolinite content shows a sharp increase at the same position as the carbon isotope negative shift initiation, indicating a simultaneous enhancement of continental weathering during volcanic activity. The changing patterns of the continental weathering intensity encompassing the Jenkyns Event also indicate that continental weathering may have functioned as a significant approach to counteract the greenhouse effect caused by substantial volcanic CO2 emissions.

Optimization of operating parameters and microbiological mechanism of a low C/N wastewater treatment system dominated by iron-dependent autotrophic denitrification

Ferrous iron (Fe2+) reduces the amount of external carbon source used for the denitrification of low-C/N wastewater. The effects of key operating parameters on the efficiency of ferrous-dependent autotrophic denitrification (FDAD) and the functioning mechanism of the microbiome can provide a regulatory strategy for improving the denitrification efficiency of low C/N wastewater. In this study, the response surface method (RSM) was used to explore the influence of four important parameters–the molar ratio of Fe2+ to NO3−-N (Fe/N), total organic carbon (TOC), the molar ratio of inorganic carbon to NO3−-N (IC/N) and sludge volume (SV, %)–on the FDAD efficiency. Functional prediction and molecular ecological networks based on high-throughputs sequencing techniques were used to explore changes in the structure, function, and biomarkers of the sludge microbial community. The results showed that Fe/N and TOC were the main parameters affecting FDAD efficiency. Higher concentrations of TOC and high Fe/N ratios provided more electron donors and improved denitrification efficiency, but weakened the importance of biomarkers (Rhodanobacter, Thermomonas, Comamonas, Thauera, Geothrix and unclassified genus of family Gallionellaceae) in the sludge ecological network. When Fe/N > 4, the denitrification efficiency fluctuated significantly. Functional prediction results indicated that genes that dominated N2O and NO reduction and the genes that dominated Fe2+ transport showed a slight decrease in abundance at high Fe/N levels. In light of these findings, we recommend the following optimization ranges of parameters: Fe/N (3.5–4); TOC/N (0.36–0.42); IC/N (3.5–4); and SV (approximately 35%).

Investigation of the migration of natural organic matter-iron-antimony nano-colloids in acid mine drainage

Colloids can potentially affect the efficacy of traditional acid mine drainage (AMD) treatment methods such as precipitation and filtration. However, it is unclear how colloids affect antimony (Sb) migration in AMD, especially when natural organic matter (NOM) is present. To conduct an in-depth investigation on the formation and migration behavior of NOM, iron (Fe), Sb and NOM-Fe-Sb colloids in AMD, experiments were performed under simulated AMD conditions. The results demonstrate significant variations in the formation of NOM-Fe-Sb colloids (1–3–450 nm) as the molar ratio of carbon to iron (C/Fe) increases within acidic conditions (pH = 3). Increasing the C/Fe molar ratio from 0.1 to 1.2 resulted in a decrease in colloid formation but an increase in particulate fraction. The distribution of colloidal Sb, Sb(III), and Fe(III) within the NOM-Fe-Sb colloids decreased from 68 % to 55 %, 72 % to 57 %, and 68 % to 55 %, respectively. Their distribution in the particulate fraction increased from 28 % to 42 %, 21 % to 34 %, and 8 % to 27 %. XRD, FTIR, and SEM-EDS analyses demonstrated that NOM facilitates the formation and crystallization of Fe3O4 and FeSbO4 crystalline phases. The formation of the colloids depended on pH. Our results indicate that NOM-Fe-Sb colloids can form when the pH ≤ 4, and the proportion of colloidal Sb fraction within the NOM-Fe-Sb colloids increased from 9 % to a maximum of 73 %. Column experiments show that the concentration of NOM-Fe-Sb colloids reaches its peak and remains stable at approximately 3.5 pore volumes (PVs), facilitating the migration of Sb in the porous media. At pH ≥ 5, stable NOM-Fe-Sb colloids do not form, and the proportion of colloidal Sb fraction decreases from 7 % to 0 %. This implies that as pH increases, the electrostatic repulsion between colloidal particles weakens, resulting in a reduction in the colloidal fraction and an increase in the particulate fraction. At higher pH values (pH ≥ 5), the repulsive forces between colloidal particles nearly disappear, promoting particle aggregation. The findings of this study provide important scientific evidence for understanding the migration behavior of NOM-Fe-Sb colloids in AMD. As the pH gradually shifts from acidic to near-neutral pH during the remediation process of AMD, these results could be applied to develop new strategies for this purpose.

Niche overlap between native Cirrhinus molitorella and potential invasive competitors

Biological invasion is one of the important reasons for the decline of freshwater biodiversity in China and even in the world. The Pearl river basin is one of the most threatened areas in China by biological invasion. Over the past four decades, mrigal carp Cirrhinus mrigala and rohu Labeo rohita have invaded the Pearl river. They potentially pose a huge threat to a well-known economic species, native mud carp Cirrhinus molitorella. However, little is known about the likely habitat distributions of these two invasive species, which limits our management of them. In this study, we detected the stable isotope ratios of nitrogen and carbon for fish and quantified their niche overlap with nicheROVER in R. The result showed that the individuals of two invasive species had a higher probability to be found in niche region of native C. molitorella (i.e., 65 % for C. mrigala and 74 % for L. rohita). Moreover, to increase understanding of their habitat distributions and potential range of spread, the existing habitats data of these three fish species obtained from previous literatures and the high-resolution bioclimatic parameters from WorldClim were analyzed via Maxent model. The results stressed that niche overlap was high among species, which could have an impact on local biodiversity in future. Furthermore, the visualization of habitat distributions could help show the dynamic habitat changes of invasive and native species over time, while also provide new insights into the subsequent prevention and control for invasive species in other river regions around the world.

Early Diagenetic Controls on Sedimentary Iodine Release and Iodine‐To‐Organic Carbon Ratios in the Paleo‐Record

AbstractIodine cycling in the ocean is closely linked to productivity, organic carbon export, and oxygenation. However, iodine sources and sinks at the seafloor are poorly constrained, which limits the applicability of iodine as a biogeochemical tracer. We present pore water and solid phase iodine data for sediment cores from the Peruvian continental margin, which cover a range of bottom water oxygen concentrations, organic carbon rain rates and sedimentation rates. By applying a numerical reaction‐transport model, we evaluate how these parameters determine benthic iodine fluxes and sedimentary iodine‐to‐organic carbon ratios (I:Corg) in the paleo‐record. Iodine is delivered to the sediment with organic material and released into the pore water as iodide (I−) during early diagenesis. Under anoxic conditions in the bottom water, most of the iodine delivered is recycled, which can explain the presence of excess dissolved iodine in near‐shore anoxic seawater. According to our model, the benthic I− efflux in anoxic areas is mainly determined by the organic carbon rain rate. Under oxic conditions, pore water dissolved I− is oxidized and precipitated at the sediment surface. Much of the precipitated iodine re‐dissolves during early diagenesis and only a fraction is buried. Particulate iodine burial efficiency and I:Corg burial ratios do increase with bottom water oxygen. However, multiple combinations of bottom water oxygen, organic carbon rain rate and sedimentation rate can lead to identical I:Corg, which limits the utility of I:Corg as a quantitative oxygenation proxy. Our findings may help to better constrain the ocean's iodine mass balance, both today and in the geological past.

Deciphering the carbon and nitrogen component conversion in humification process mediated by distinct microbial mechanisms in composting from different domestic organic wastes.

This study aimed to compare the process of maturity and humus fraction evolution as well as bacterial community dynamics in composting from different domestic organic wastes (food waste (FW), and vegetable waste (VW)) and decipher the key biotic influencing factors of humic acid formation through correlation analysis and ecological network. The results showed that organic carbon components in FW with high ratio of soluble organic carbon and hemicellulose were more easily to be degraded in composting compared to VW. After 30days of composting, the content of HA-C generated by VW was 35.41%, higher than 29.01% of FW, and the growth rate of HA-C generated was 38.42% and 28.34%, respectively. PARAFAC analysis showed that the structure of HA generated in VW was more complex, and the proportion of humic acid-like components (C3 + C4) was 60.32%, while FW only accounted for 43.86%. However, the evolution growth rate of aromatic components in HA in FW was 26.88% in 30days of compost, which was higher than 15.17% in VW. High-throughput sequencing indicated that Lactobacillus was the initial dominated genera in composting from different domestic wastes. Thermobifida, Thermovum, and Pusillimas as well as Aeribacillus were core bacterial genera that promoted the humification process in FW and VW, respectively. Network analysis showed that there was higher bacterial interacted connection degree and complexity in FW compared to VW. This study was of great significance for optimizing organics conversion and humification efficiency of household waste composting.

Assessment of the Seasonal Potential of Macroalgae and Grass in the Sea of Azov for Methanogenesis and Optimization of the Digestate’s Carbon/Nitrogen Ratio

Large amounts of macroalgae and grass are dumped on the shores of the Sea of Azov in different seasons. Aquatic plant biomass management could contribute to sustainable development. By mixing them with co-substrates in an anaerobic bioreactor, not only can biogas be extracted, but suitable fertilizers can also be obtained. This study discusses the possibility of using methanogenesis waste from Azov Sea algae and sea grass as a fertilizer for agriculture. The main criterion is the presence of carbon (C) and nitrogen (N) in the waste products of methanogenesis. The influence of climatic and seasonal factors in the Azov region on the quality and quantity of storm emissions, on the productivity of methanogenesis, and changes in the ratio of carbon (C) and nitrogen (N) during methanogenesis and in the fermented substrate has been established. The influence of the ratio of the components of the mixture in various proportions, before methanogenesis, on the productivity of methanogenesis and the change in the ratio of carbon (C) and nitrogen (N) during the process of methanogenesis, and in the fermented substrate were studied. The biomass of the Sea of Azov, cattle manure and wastewater waste in various proportions, were used as components of the mixture. Recommendations are given for the selection of mixture components for methanogenesis, with predicted indicators of the ratio of carbon (C) and nitrogen (N) in the fermented substrate.

Heterogeneous environmental consciousness, carbon permit adoption, and endogenous growth: A case of China

Motivated by low participation rate in China’s pilot Emission Trading Schemes (ETS), yet there being ample empirical evidence of carbon permit activities having an impact on firms’ technological innovation choice, we develop a novel endogenous growth model with carbon accumulation where both the green behaviors of non-corporate individuals and carbon permit adoption choice of corporate owners are influenced by heterogeneous environmental consciousness. Calibrated for China based on ETS price data, we examine the impacts of both long-run policy experiments and short-run cyclicality associated with carbon permit prices. we find that long-term greater ETS trading affordability would incentivize more firms to participate and bring about a reduction in carbon ratio, though it is still largely bounded by the conventional environment-growth trade-off that it requires supplementing it with other policies. In the short run, we find that higher carbon permit trading price would be procyclical to economic expansion but at the cost of environmental degradation too. In combination, this presents a policy dilemma: while improving ETS trading affordability is a long-run policy priority in China, in the short-run, absent fundamental changes, the procyclicality between carbon permit price and economic growth would serve as counteracting forces to this.

Simultaneous fMRI and metabolic MRS of hyperpolarized [1-13C]pyruvate during nicotine stimulus in rat.

Functional MRI (fMRI) and MRS (fMRS) can be used to noninvasively map cerebral activation and metabolism. Recently, hyperpolarized 13C spectroscopy and metabolic imaging have provided an alternative approach to assess metabolism. In this study, we combined 1H fMRI and hyperpolarized [1-13C]pyruvate MRS to compare cerebral blood oxygenation level-dependent (BOLD) response and real-time cerebral metabolism, as assessed with lactate and bicarbonate labelling, during nicotine stimulation. Simultaneous 1H fMRI (multislice gradient echo echo-planar imaging) and 13C spectroscopic (single slice pulse-acquire) data were collected in urethane-anaesthetized female Sprague-Dawley rats (n= 12) at 9.4 T. Animals received an intravenous (i.v.) injection of either nicotine (stimulus; 88 μg/kg, n= 7, or 300 μg/kg, n= 5) or 0.9% saline (matching volume), followed by hyperpolarized [1-13C]pyruvate injection 60 s later. Three hours later, a second injection was administered: the animals that had previously received saline were injected with nicotine and vice versa, both followed by another hyperpolarized [1-13C]pyruvate i.v. injection 60 s later. The low-dose (88 μg/kg) nicotine injection led to a 12% ± 4% (n= 7, t-test, p~ 0.0006 (t-value -5.8, degrees of freedom 6), Wilcoxon p~ 0.0078 (test statistic 0)) increase in BOLD signal. At the same time, an increase in 13C-bicarbonate signal was seen in four out of six animals. Bicarbonate-to-total carbon ratios were 0.010 ± 0.004 and 0.018 ± 0.010 (n= 6, t-test, p~ 0.03 (t-value -2.3, degrees of freedom 5), Wilcoxon p~ 0.08 (test statistic 3)) for saline and nicotine experiments, respectively. No increase in the lactate signal was seen; lactate-to-total carbon was 0.16 ± 0.02 after both injections. The high (300 μg/kg) nicotine dose (n= 5) caused highly variable BOLD and metabolic responses, possibly due to the apparent respiratory distress. Simultaneous detection of 1H fMRI and hyperpolarized 13C-MRS is feasible. A comparison of metabolic response between control and stimulated states showed differences in bicarbonate signal, implying that the hyperpolarization technique could offer complimentary information on brain activation.

Modification of cotton yarns utilizing graphene ink to functionalized as conductivity

In this study, the oxidation and reduction method was combined with chemical and hydrothermal method to prepare graphene ink for high electrical conductivity. The prepared ink samples were subsequently analyzed using a scanning electron microscope (SEM) and an X-ray dispersion spectrometer (EDS). The resulting samples displayed a deposition of extremely thin slices and consistent geometric shapes with a thickness from 3 to 1 nm. Moreover, the weighty and atomic ratios of carbon and oxygen in the samples were 48.75 and 36.59%, respectively; the carbon ratio was higher than the oxygen ratio. Open-end, carded, and combed cotton yarn samples were coated using the surface coating technique. The tensile strength of the treated cotton yarns was tested and analyzed. On the open-end yarn sample’s surface, thin slices of graphene were densely present. Additionally, the open-end yarn’s atomic ratios of carbon and oxygen were 5.4 and 7.3%, respectively. Sample’s electrical resistance was constant even after 12 washes; the open-end yarn had the lowest electrical resistance. The suitability of the treated yarns for use in heat generation applications was studied. As a result, by increasing the applied voltage and the number of graphene ink layers, the open-end yarn temperature rises to 55 °C. The open-end yarn temperature was increased by increasing the number of applied graphene layers. This finding suggests that these yarns could be used in wearable smart textiles that generate heat.

Orthogonal Experimental Study on the Ratio of Similar Materials of Coal Body

According to the coal samples collected from Zhaogu No.2 Coal Mine as raw coal samples, the similar materials of coal body were studied by using river sand, pulverized coal, Portland cement and calcium carbonate. The orthogonal test method of four factors (bone glue ratio, aggregate ratio, rubber ratio, water mixing rate) and three levels was used to obtain the physical and mechanical parameters such as density, uniaxial compressive strength, elastic modulus, cohesion, internal friction angle and tensile strength of coal similar materials. The range analysis method was used to obtain the key influencing factors and variation rules of the physical and mechanical properties of coal similar materials. Finally, the method of multiple linear regression analysis was used to obtain the similar material ratio that was most consistent with the mechanical properties index of raw coal. The ratio of calcium carbonate: cement: river sand: coal powder: water = 1: 5: 0.9: 5.9: 3.2. The density error, compressive strength error, elastic modulus error and cohesion error of coal sample and raw coal are small, which proves that the similar material is similar to the mechanical properties of raw coal, and provides guidance for subsequent research.

Late Miocene drainage reorganization on the NE Tibetan Plateau linked to growth of the Qilian Shan revealed by coupled carbonate Sr-silicate Nd isotopic tracers

The tectonically active NE Tibetan Plateau, which is located at the confluent area of the humid Asian monsoon region and dry Asian inlands, provides excellent archives of drainage pattern evolution in response to regional changes in topography and climate. However, the uplift of the NE Tibetan Plateau and formation of modern drainage patterns are still disputed. In this study, based on the SrNd isotopic distribution in modern surface water and sediments, we present integrated records of 87Sr/86Sr ratios in carbonate and 87Sr/86Sr-εNd(0) values in silicate of the Huaitoutala section in the northern Qaidam Basin to reveal the source-to-sink history of particulate and dissolved loads since ∼15 Ma. Our results show that changes in SrNd isotopes at ca. 10 Ma and ca. 5 Ma are indicative of two stages of source alteration and reorganization of the drainage system. Specifically, a remarkable increase in 87Sr/86Sr ratios in carbonate and silicate together with a decrease in εNd(0) values since ca. 10 Ma suggests a tectonic denudation event of Qilian Shan at ∼10 Ma. The subsequent declines in 87Sr/86Sr ratios in carbonate and silicate together with an increase in εNd(0) values since ca. 5 Ma, which approach the modern 87Sr/86Sr ratios near the study section site, suggest that a modern-like drainage pattern in the northern Qaidam Basin might have formed in response to tectonic uplift of Qilian Shan at ca. 5 Ma. Using coupled carbonate Sr-silicate SrNd isotopes, we provide reliable provenance tracers of drainage reorganization and the evolution of source-to-sink systems caused by tectonic deformation.

Stable isotopes in the shell organic matrix for (paleo)environmental reconstructions

Stable isotope ratios of mollusc shell carbonates have long been used to reconstruct past environmental conditions. Although shells also contain organics, they are seldom used in (paleo)climatic studies. Here, we extract the acid-soluble and insoluble fractions of the organic matrix of modern Mytilus galloprovincialis shells from three sites along a coast–to-upper-estuary environmental gradient to measure their hydrogen (δ2H) and oxygen (δ18O) isotope compositions. Both organic fractions showed isotopic signatures significantly different from those of carbonate and water at each site, indicating the involvement of different fractionation mechanisms. The soluble fraction showed gradual differences in isotope values along the gradient, while the insoluble fraction showed δ2H-δ18O correlation regressions subparallel to the Global and Local Meteoric Water Lines. These results showed the great potential of the shell organic matrix stable isotopes as possible (paleo)environmental proxies, stimulating further research to better define the fractionation mechanisms involved.