Nitrogen Atmosphere Research Articles

Exploring Sustainable Agriculture with Nitrogen-Fixing Cyanobacteria and Nanotechnology.

The symbiotic relationship between nitrogen-fixing cyanobacteria and plants offers a promising avenue for sustainable agricultural practices and environmental remediation. This review paper explores the molecular interactions between nitrogen-fixing cyanobacteria and nanoparticles, shedding light on their potential synergies in agricultural nanotechnology. Delving into the evolutionary history and specialized adaptations of cyanobacteria, this paper highlights their pivotal role in fixing atmospheric nitrogen, which is crucial for ecosystem productivity. The review discusses the unique characteristics of metal nanoparticles and their emerging applications in agriculture, including improved nutrient delivery, stress tolerance, and disease resistance. It delves into the complex mechanisms of nanoparticle entry into plant cells, intracellular transport, and localization, uncovering the impact on root-shoot translocation and systemic distribution. Furthermore, the paper elucidates cellular responses to nanoparticle exposure, emphasizing oxidative stress, signaling pathways, and enhanced nutrient uptake. The potential of metal nanoparticles as carriers of essential nutrients and their implications for nutrient-use efficiency and crop yield are also explored. Insights into the modulation of plant stress responses, disease resistance, and phytoremediation strategies demonstrate the multifaceted benefits of nanoparticles in agriculture. Current trends, prospects, and challenges in agricultural nanotechnology are discussed, underscoring the need for responsible and safe nanoparticle utilization. By harnessing the power of nitrogen-fixing cyanobacteria and leveraging the unique attributes of nanoparticles, this review paves the way for innovative, sustainable, and efficient agricultural practices.

Silicon nitride stoichiometry tuning for visible photonic integrated components

In integrated photonics, silicon nitride-based devices operating in the visible range of light may experience auto-fluorescence, an undesired effect that can interfere with the propagating signal. In this article, a reduction in auto-fluorescence has been obtained by studying stoichiometric and silicon-rich silicon nitride, subjected to different post-thermal annealings in different atmospheres. Stoichiometric silicon nitride treated with rapid thermal annealing at 1100 °C in an argon atmosphere reduces the photoluminescence intensity of the material by 95%. Silicon-rich nitride shows a more stable photoluminescence response to different annealings and atmospheres than the stoichiometric. Compared to the stoichiometric material, the emission peaks experienced by the silicon-rich silicon nitride are red shifted between 140 and 190 nm, and the refractive index value is increased by 7% at 633 nm. Also, the interface effects have been studied, showing a remarkable contribution when the annealing is performed in an argon atmosphere, while no contribution from these effects is observed in a nitrogen atmosphere. Finally, taking advantage of the refractive index variation between nitrides, a vertical directional coupler using two asymmetric waveguides, one of each type of silicon nitride, has been designed and simulated, obtaining a coupling length of 9.8 μm with a coupling power of 95.8%, demonstrating the 3D integration capabilities of combining silicon nitride layers of variable composition.

Multicomponent Nanoparticles Decorating a Lignin-Derived Biochar Composite for 2-Nitrophenol Sensing

Lignin, which contains aromatic phenols, is the second most abundant renewable biomass material in the world. It is the main byproduct of the paper industry and is characterized by abundant sources, renewability, and low cost. The present study focused on the extraction of lignin from poplar wood through a straightforward papermaking approach, thereafter utilizing the resultant black liquor containing lignin for synthesizing lignin-based phenolic resins. During the polymerization process, cobalt (Co) and nickel (Ni) species were introduced and, subsequently, a CoNi/biochar catalyst was obtained through pyrolysis in a nitrogen atmosphere. The prepared catalyst possessed rough spherical structures. The incorporation of Co and Ni enhanced charge redistribution, thereby imparting the catalyst with strong electron acceptance capabilities. The prepared lignin-based phenolic-resin-derived carbon was used for the electrochemical sensing of 2-nitrophenol. The limit of detection (LOD) for 2-nitrophenol was calculated to be 0.0132 µM, with good repeatability, stability, and selectivity.

Shifts in evolutionary lability underlie independent gains and losses of root-nodule symbiosis in a single clade of plants

Root nodule symbiosis (RNS) is a complex trait that enables plants to access atmospheric nitrogen converted into usable forms through a mutualistic relationship with soil bacteria. Pinpointing the evolutionary origins of RNS is critical for understanding its genetic basis, but building this evolutionary context is complicated by data limitations and the intermittent presence of RNS in a single clade of ca. 30,000 species of flowering plants, i.e., the nitrogen-fixing clade (NFC). We developed the most extensive de novo phylogeny for the NFC and an RNS trait database to reconstruct the evolution of RNS. Our analysis identifies evolutionary rate heterogeneity associated with a two-step process: An ancestral precursor state transitioned to a more labile state from which RNS was rapidly gained at multiple points in the NFC. We illustrate how a two-step process could explain multiple independent gains and losses of RNS, contrary to recent hypotheses suggesting one gain and numerous losses, and suggest a broader phylogenetic and genetic scope may be required for genome-phenome mapping.

Decomposition of HCN during Experimental Impacts in Dry and Wet Planetary Atmospheres.

Hydrogen cyanide (HCN), a key molecule of significant importance in contemporary perspectives on prebiotic chemistry, originates in planetary atmospheres from various processes, such as photochemistry, thermochemistry, and impact chemistry, as well as from delivery by impacts. The resilience of HCN during periods of heavy bombardment, a phenomenon caused by an influx of material on unstable trajectories after accretion, remains relatively understudied. This study extensively investigates the stability of HCN under impact conditions simulated using a laboratory Nd:YAG laser in the ELISE experimental setup. High-resolution infrared spectroscopy was employed to monitor the gas phase composition during these simulations. Impact chemistry was simulated in bulk nitrogen atmospheres with varying mixing ratios of HCN and water vapor. The probed range of compositions spans from ∼0 to 1.8% of HCN and 0 to 2.7% of H2O in a ∼1 bar nitrogen atmosphere. The primary decomposition products of HCN are CO and CO2 in the presence of water and unidentified solid phase products in dry conditions. Our experiments revealed a range of initial HCN decomposition rates between 2.43 × 1015 and 5.17 × 1017 molec J-1 of input energy depending on the initial composition. Notably, it is shown that the decomposition process induced by the laser spark simulating the impact plasma is nonlinear, with the duration of the irradiation markedly affecting the decomposition rate. These findings underscore the necessity for careful consideration and allowance for margins when applying these rates to chemical models of molecular synthesis and decomposition in planetary atmospheres.

Comprehensive analysis on the combined effects of reaction kinetics and heat transfer on biomass pyrolysis

The current study links the heat transport phenomena and reaction kinetics when the pyrolysis was occurring of sugarcane bagasse (SCB) biomass. A thermogravimetric analyzer was used to conduct a kinetic research on the pyrolysis of biomass in a nitrogen atmosphere, covering a heating rate range of 10–40 °C/min. The thermogravimetric studies (TGA) allowed for the differentiation of three stages associated with the breakdown of hemicellulose, cellulose, and lignin. Using three first-order processes and the Arrhenius theory, the activation energy and pre-exponential factor were determined.Three important components of biomass—lignin, hemicellulose, and cellulose—were assumed to respond independently and in parallel in the kinetics model. Additionally, the transport characteristics of each component were assessed using their respective kinetic values and other thermo-physical characteristics. The regulating mechanism was then anticipated by the heat transfer map for three elements with different particle sizes. The transfer qualities were mainly influenced by particle size, at a crucial dimension dictating the shift in the system for several parts.

ТЕРМОСТОЙКОСТЬ ЗАЛИВОЧНЫХ ПЕНОПОЛИИЗОЦИАНУРАТОВ

In the modern construction industry for increasing the thermal resistance of structures and reducing heat losses, casting foams based on reactive oligomers with high performance characteristics are widely used. At the same time, special attention is paid to the use of polyisocyanurate foams (PIR). However, in the scientific and technical literature there are practically no data on the influence of the composition of polyisocyanurate foams on their thermal properties. The purpose of this work is to determine the influence of isocyanate/polyol ratio, modifier content (trichloropropyl phosphate) and apparent density of foams on thermal properties of casting PIRs. The thermal properties of PIRs, when heated in the temperature range of 30-800 ⁰C in nitrogen atmosphere and in air, were investigated using a multimodal thermal analytical complex DuPont-9900 (heating rate 20°C/min). It is revealed that thermo-oxidative decomposition of polyisocyanurate foams is a pronounced, two-stage process, and the destruction of PIR in inert medium (nitrogen) is a one-stage process, which indicates different mechanisms of decomposition of foams in air and nitrogen. As a result of experimental studies, it was revealed that the investigated PIRs are more resistant to thermo-oxidative degradation than to thermal degradation. The thermal properties of the above foams depend on the isocyanate/polyol ratio and TCPP content. The density of polyisocyanurate foams insignificantly affects their thermal stability. At the optimal content of initial components PIRs have higher thermal resistance compared to rigid polyurethane foams (FPU).

Unlocking the diversity and plant‐growth promoting potential of the bulk soil bacteria associated with the Saharan tree Vachellia tortilis subsp. raddiana

AbstractIn this study, we investigated the bacterial diversity and plant growth‐promoting (PGP) properties of bulk soil bacteria of Vachellia tortilis subsp. raddiana collected from the Taidalt and Amazloug nature preserves area in southern Morocco. Using repetitive extragenic palindromic polymerase chain reaction fingerprinting and 16S rDNA sequencing, 93 strains were identified. They belonged mainly to the genera Bacillus and Peribacillus. In vitro tests for PGP traits showed high levels of activity for strains belonging to the genera Bacillus and Pseudomonas. It was relevant that several Bacillus strains produced auxin (maximum amount 262.61 µg mL−1 for Bacillus sp. LMR1097), solubilized phosphate (maximum amount 22.10 µg mL−1), or produced siderophores, while three strains were able to fix atmospheric nitrogen (LMR1145, LMR1013, and LMR1015). Inoculation of V. tortilis subsp. raddiana plants with selected bacterial strains (LMR881 and LMR1097) increased shoot and root growth parameters. The strain Pantoea sp. LMR881 had the highest mean values for shoot and root length (24.60–14.80 cm) and shoot dry weight (1.31 g), whereas Bacillus sp. LMR1097 showed the lowest mean shoot dry weight. Overall, these results highlight the potential of using selected native bacterial inoculants for improving growth of candidate tree plants to be used in restoration programs of arid degraded areas.

Comparison of the Erosive Wear Resistance of Ductile Cast Iron Following Laser Surface Melting and Alloying

This article presents research results on the influence of the laser surface melting and alloying processes on the erosive wear resistance of ductile cast iron. For the research, an EN-GJS 350-22 ductile cast iron surface was laser-melted and laser-alloyed with titanium powder in an argon and nitrogen atmosphere. Solid-particle erosion tests were carried out on the laser-melted and -alloyed surface layers and the base material according to the ASTM G76-04 standard with 30° and 90° impingement angles. The erosive wear resistance results were correlated with Vickers hardness and microstructural test results with the use of SEM (scanning electron microscopy), TEM (transmission electron microscopy), EDS (energy dispersive spectroscopy), and XRD (X-ray diffraction). The mechanisms of erosive wear were also analyzed for the laser-treated surface layers and the base material. The research showed that the laser melting and alloying processes with titanium powder had a positive effect on the hardness and erosive wear resistance of the ductile cast iron surface due to microstructure modification. Moreover, despite the lower hardness of the laser-alloyed surface layers, their composite microstructure had a positive impact on the erosive wear resistance in comparison to the laser-melted surface layers.

Green Manure for Sustainable Crop Production: A Review

Green manuring is an economical and eco-friendly scientific approach to achieve more resilient and sustainable food production for agricultural systems. Incorporation of green manure improves soil condition by increasing soil physical, chemical and biological properties such as organic matter, availability of nitrogen, phosphorus and potassium and also improves soil structure by preventing soil erosion, increasing water holding capacity etc. Green manure acts as a natural fertilizer, releasing nutrients into the soil as it decomposes and increases the nutrient content in the soil and shows positive effect on plant growth and development. Addition of green manure crops contribute to greater fixation of atmospheric nitrogen, and when decomposed, makes the nitrogen availability in the soil, reducing the need for synthetic nitrogen fertilizers in crops. Furthermore, it has a significant impact on several plant growth and yield parameters, resulting in increased agricultural productivity and ecosystem health.

Quantification and kinetics of nitrogen mass gain during high temperature oxidation of titanium in air

Improving the high-temperature oxidation resistance of titanium alloys in air is a prerequisite for extending their use in turbojet engines. A better understanding of the role of atmospheric nitrogen is required for this purpose. Here, we studied the insertion kinetics of nitrogen in titanium at 650 °C in air up to 100 h. Moreover, the nitrogen mass gain, and its ratio over the total mass gain, were quantified as a function of the oxidation duration by using Nuclear Reaction Analysis. It was found that nitrogen inserts into titanium with a parabolic kinetics and a rate constant about 1500 times smaller than oxygen.

Prevalence, diversity and applications potential of nodules endophytic bacteria: a systematic review.

Legumes are renowned for their distinctive biological characteristic of forming symbiotic associations with soil bacteria, mostly belonging to the Rhizobiaceae familiy, leading to the establishment of symbiotic root nodules. Within these nodules, rhizobia play a pivotal role in converting atmospheric nitrogen into a plant-assimilable form. However, it has been discerned that root nodules of legumes are not exclusively inhabited by rhizobia; non-rhizobial endophytic bacteria also reside within them, yet their functions remain incompletely elucidated. This comprehensive review synthesizes available data, revealing that Bacillus and Pseudomonas are the most prevalent genera of nodule endophytic bacteria, succeeded by Paenibacillus, Enterobacter, Pantoea, Agrobacterium, and Microbacterium. To date, the bibliographic data available show that Glycine max followed by Vigna radiata, Phaseolus vulgaris and Lens culinaris are the main hosts for nodule endophytic bacteria. Clustering analysis consistently supports the prevalence of Bacillus and Pseudomonas as the most abundant nodule endophytic bacteria, alongside Paenibacillus, Agrobacterium, and Enterobacter. Although non-rhizobial populations within nodules do not induce nodule formation, their presence is associated with various plant growth-promoting properties (PGPs). These properties are known to mediate important mechanisms such as phytostimulation, biofertilization, biocontrol, and stress tolerance, emphasizing the multifaceted roles of nodule endophytes. Importantly, interactions between non-rhizobia and rhizobia within nodules may exert influence on their leguminous host plants. This is particularly shown by co-inoculation of legumes with both types of bacteria, in which synergistic effects on plant growth, yield, and nodulation are often measured. Moreover these effects are pronounced under both stress and non-stress conditions, surpassing the impact of single inoculations with rhizobia alone.

Enhanced electrochemical performance of Ba0.5Sr0.5Co0.8Fe0.2O3-δ cathode by Zr4+, Sm3+ and Yb3+ tri-doped BaCeO3 compositing for intermediate-temperature thin-film fuel cells

In this study, Zr4+, Sm3+ and Yb3+ tri-doped BaCeO3 (BaCe0.7Zr0.1Sm0.1Yb0.1O3-α) was prepared using a citric acid-EDTA combined complexing sol-gel method. The influence of sintering aid (CuO) content on structure, sinter-ability and conductivity of BaCe0.7Zr0.1Sm0.1Yb0.1O3-α (BCZSY) was studied using XRD, SEM and AC impedance. XRD patterns of different sintering aid contents and temperatures showed that all samples formed a pure BaCeO3 orthorhombic phase without any impurities. The conductivity of 1500-BCZSY reached 1.8 × 10−2 S cm−1 and 1.9 × 10−2 S cm−1 in dry nitrogen and hydrogen atmospheres at 700 °C, respectively. The anode-supported membrane fuel cells of NiO-BCZSY | BCZSY (13 μm) | Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) and NiO-BCZSY | BCZSY (15 μm) | BCZSY-BSCF were fabricated, respectively. SEM results showed that the cathode, anode-support and electrolyte had good adhesion. The polarization resistance (Rp) of BCZSY-BSCF was significantly reduced by 34 %, 44 % and 55 % compared to BSCF at 500 °C, 550 °C and 600 °C, respectively. The maximum power density (Pmax) using BCZSY-BSCF as the cathode increased by 18 %, 17 % and 22 % compared to BSCF at 500 °C, 550 °C and 600 °C under the condition of slightly higher electrolyte film thickness, correspondingly.

Mechanics manipulation in large-area organic solar modules achieving over 16.5 % efficiency

High-efficiency organic solar cells (OSCs) are typically produced through spin-coating, restricting their application to small areas. Blade-coating, however, emerging as a promising method for large-scale production, yet faces challenges in film morphology optimization, which often leads to reduced power conversion efficiency (PCE). This study delves into the influence of both liquid and solid additives on the morphology of active layer in blade-coated OSCs, comparing them with spin-coated counterparts, using the high-efficiency PM6:D18:BTP-eC9 active layer. For the first time, we discovered the distinct impacts of solid versus liquid additives on the film uniformity, phase separation and crystalline regulation in blade-coating technique. Our findings reveal that liquid additives in blade-coating trigger outward Marangoni flow, causing undesirable material aggregation and phase separation, thereby impairing device performances. Conversely, switching to solid additives, like 1,4-Diiodobenzene (DIB), prevents these detrimental changes in fluid mechanics and preserves the desired additive effects. We demonstrate that solid additives can significantly change these inferior behaviors introduced by liquid additives in blade-coating, regulate phase separation, enhance π-π accumulation and delay crystallization, and ultimately boost OSC efficiency. Using DIB solid additive, we achieved a PCE of 18.81 % in blade-coated devices. Scaling up by 252 times, the PCE of large-area OSC module (15.64 cm²) sustained at 16.70 % (certified 16.66 %), ranking among the highest efficiency for OSC modules reported so far. These modules also exhibited exceptional storage stability, retaining 98 % efficiency after 5880 h in a nitrogen atmosphere. This research also provides a comprehensive understanding from various film characterizations and the perspective of fluid mechanics normally lack in the research. This research not only establishes a new framework for high-performance and large-area OSC modules but also extends its findings to other OSC systems with different additives, demonstrating a roll-to-roll compatible technique.

Stable Organic Solar Cells Enabled by Simultaneous Hole and Electron Interlayer Engineering

The development of high‐performance organic solar cells (OSCs) with high operational stability is essential to accelerate their commercialization. Unfortunately, our understanding of the origin of instabilities in state‐of‐the‐art OSCs based on bulk heterojunction (BHJ) featuring non‐fullerene acceptors (NFAs) remains limited. Herein, we developed NFA‐based OSCs using different charge extraction interlayer materials and studied their storage, thermal, and operational stabilities. Despite the high power conversion efficiency (PCE) of the OSCs (17.54%), we found that cells featuring self‐assembled monolayers (SAMs) as hole‐extraction interlayers exhibited poor stability. The time required for these OSCs to reach 80% of their initial performance (T80) was only 6 h under continuous thermal stress at 85 °C in a nitrogen atmosphere and 1 h under maximum power point tracking (MPPT) in a vacuum. Inserting MoOx between ITO and SAM enhanced the T80 to 50 and ~15 h after the thermal and operational stability tests, respectively, while maintaining a PCE of 16.9%. Replacing the organic PDINN electron transport layer with ZnO NPs further enhances the cells' thermal and operational stability, boosting the T80 to 1000 and 170 h, respectively. Our work reveals the synergistic roles of charge‐selective interlayers and device architecture in developing efficient and stable OSCs.

Interruption after Short-Term Nitrogen Additions Improves Ecological Stability of Larix olgensis Forest Soil by Affecting Bacterial Communities.

Atmospheric nitrogen deposition can alter soil microbial communities and further impact the structure and function of forest ecosystems. However, most studies are focused on positive or negative effects after nitrogen addition, and few studies pay attention to its interruption. In order to investigate whether interruption after different levels of short-term N additions still benefit soil health, we conducted a 2-year interruption after a 4-year short-term nitrogen addition (10 and 20 kg N·hm-2·yr-1) experiment; then, we compared soil microbial diversity and structure and analyzed soil physicochemical properties and their correlations before and after the interruption in Larix olgensis forest soil in northeast China. The results showed that soil ecological stabilization of Larix olgensis forest further improved after the interruption compared to pre-interruption. The TN, C:P, N:P, and C:N:P ratios increased significantly regardless of the previous nitrogen addition concentration, and soil nutrient cycling was further promoted. The relative abundance of the original beneficial microbial taxa Gemmatimonas, Sphingomonas, and Pseudolabrys increased; new beneficial bacteria Ellin6067, Massilia, Solirubrobacter, and Bradyrhizobium appeared, and the species of beneficial soil microorganisms were further improved. The results of this study elucidated the dynamics of the bacterial community before and after the interruption of short-term nitrogen addition and could provide data support and a reference basis for forest ecosystem restoration strategies and management under the background of global nitrogen deposition.

Synergistic co-pyrolysis of corn stover and refuse-derived fuel with microplastics: Kinetic and thermodynamic study

Biomass and refuse-derived fuel are prevalent constituents of municipal solid waste worldwide, exerting persistent pressures on environmental ecosystems. Consequently, there arises a critical necessity for their effective recycling and management. This study investigates the co-pyrolysis of corn stover (CS) and Refuse-Derived Fuel (RDF) in a 1:1 mass ratio through kinetic and thermodynamic analyses. Using a thermogravimetric analyzer and differential scanning calorimetry (DSC), the co-pyrolysis process is examined within a temperature range of 25–900 °C, under varying heating rates of 5, 10, and 20 °C/min in a nitrogen atmosphere. Kinetic analysis is conducted employing model-free methods, including Kissinger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (FWO), Starink, and Tang, with subsequent estimation of thermodynamic parameters such as enthalpy change (ΔH), entropy change (ΔS), and Gibbs free energy (ΔG). Additionally, mass and energy balances specific to the blended feedstock are calculated to evaluate future operational efficiency. The investigation reveals the higher heating values (HHV) of CS and RDF as 17.879 and 20.035 kJ/kg, respectively. Notably, the DTG and DSC curves indicate a positive interaction between CS and RDF's plastic component at temperatures exceeding 400 °C. Kinetic analysis yields average activation energies for CS, RDF, and the CS-RDF blend (1:1) as 202.26, 235.87, and 212.60 kJ/mol, respectively, suggesting a reduction in activation energy for the blend. In summary, these findings offer valuable insights into the co-pyrolysis of CS and RDF, thereby contributing to the optimization of co-pyrolysis as an effective waste-to-energy conversion process.

A Decadal Change in Atmospheric Nitrogen Deposition at a Rural Site in Southern China

Elevated atmospheric reactive nitrogen (Nr) emissions and the subsequent nitrogen (N) deposition have negatively impacted the global environment, particularly in China. In order to assess the long-term trends in atmospheric N deposition in the south of China, Taojiang County in Hunan Province was selected as a representative rural area for study. We analyzed interannual variation in atmospheric Nr, including gaseous ammonia (NH3), nitrogen dioxide (NO2), nitrate acid (HNO3) vapor, particulate ammonium (NH4+), and nitrate (NO3−) in air and NH4+-N and NO3−-N in precipitation from 2011 to 2020. The 10-year average atmospheric wet-plus-dry N deposition was 41.9 kg N ha−1 yr−1, which decreased by approximately 24% after 2012, indicating that NH3 and NOx emissions were effectively reduced by emission controls introduced in 2013. Wet deposition accounted for approximately 74% of the total N deposition and was significantly influenced by annual precipitation amount. Reduced N (NH3, pNH4+, and NH4+ in rainwater) was the dominant form, comprising approximately 58% of the total N deposition, while oxidized N (pNO3−, NO2, HNO3, and NO3− in rainwater) accounted for 42% of the total N deposition. Atmospheric HNO3, NO2, and NH3 concentrations and deposition declined by 30–80% over the decade, while particulate NH4+ and NO3− concentrations and deposition remained at relatively stable levels, which suggests that ongoing research and policy should focus on rural particulate pollution. Future strategies must concentrate on the integrated control of NH3 and NOx emissions to mitigate air pollution and protect human health, particularly in rural areas because current abatement efforts are primarily directed toward urban areas and the industrial sector, whereas non-point source NH3 pollution, influenced mainly by agricultural activities, dominates in rural regions.

Catalytic performance of modified carbon black on methane decomposition for hydrogen production.

Carbon-based catalysts catalyze methane decomposition to produce hydrogen is a very attractive technical route. Carbon black in carbon-based catalysts has the advantages of high catalytic activity, good stability and better tolerance to toxic impurities such as sulphur in the feedstock, which has become a hot topic of research for many scientists. In this work, the effect of heat treatment on the structural and surface properties of carbon blacks and their catalytic performance in hydrogen production from methane decomposition was investigated. A commercial carbon blacks N110 was selected to heat treatment with nitrogen or carbon dioxide atmosphere at 850 °C, respectively. The Raman spectrums indicated that the graphitization degree of modified carbon under two atmospheres were promoted with the treatment time increasing. BET results revealed that the specific surface area of the carbon black treated under carbon dioxide increased, while the specific surface area was unchanged for that of the carbon black treated under nitrogen. The catalytic test of the two modified carbon blacks for methane decomposition exhibited the almost same activity, which meant that the graphitization degree of carbon black is the key factor for methane decomposition rather than the specific surface area. It was suggested that highly graphitized carbon black could be used as the potential catalysts for hydrogen production from methane decomposition.

Transcriptional and physiological analyses uncover the mineralization and uptake mechanisms of phytic acid in symbiotically grown Vicia faba plants

Legume-rhizobia symbiosis requires high phosphorus (P) in the form of ATP to convert atmospheric nitrogen (N) into ammonia. The fixed ammonia is converted to NH4+ by H+-ATPase via protonation. To the best of our knowledge, most of these research works resort to using only inorganic P (Pi) to the neglect of the organic P (Po) counterpart. As it stands, the potential regulating roles of plasma membrane (PM) H+-ATPases during legume-rhizobia symbiosis in response to phytic acid supply and how it alters and modulates the regulation of PM H+-ATPases remain obscure. To contribute to the above hypothesis, we investigate the mechanisms that coordinately facilitate the growth, uptake, and transcript expression of PM H+-ATPase gene isoforms in response to different P sources when hydroponically grown Vicia faba plants were exposed to three P treatments, viz., low- and high-Pi (2.0 and 200 μM KH2PO4; LPi and HPi), and phytic acid (200 μM; Po) and inoculated with Rhizobium leguminosarum bv. viciae 384 for 30 days. The results consistently reveal that the supply of Po improved not only the growth and biomass, but also enhanced photosynthetic parameters, P uptake and phosphatase activities in symbiotically grown Vicia faba relative to Pi. The supply of Po induced higher transcriptional expression of all PM H+-ATPase gene isoforms, with possible interactions between phosphatases and H+-ATPase genes in Vicia faba plants when exclusively reliant on N derived from nodule symbiosis. Overall, preliminary results suggest that Po could be used as an alternative nutrition in symbiotic crops to improve plant growth.