Oxygen-deficient Environment Research Articles

The Corrosion Behavior of Carbon Steel Materials Used at Nuclear Power Plants During Deactivation and Decommissioning Processes

This study is focused on the corrosion behavior of carbon steel A106 B in a static water environment, which simulated the decommissioning transition phase of BWR power plants. When the autoclave was filled with stagnant water, the corrosion rates of carbon steel pipe for the cold-drawn and hot-rolled samples were 23 μm/year and 19 μm/year, respectively. When the autoclave was not completely filled with water, leaving the samples fully submerged, the corrosion rate for the hot-rolled sample increased to 88 μm/year. In an autoclave with periodic water flow, the corrosion rate for the cold-drawn sample decreased to 11 μm/year. When the autoclave was not completely filled with water, the sample positioned at the air–water interface exhibited the highest corrosion rate of approximately 102 μm/year. These results indicate that the influence of ion concentration on the corrosion rate outweighed that of dissolved oxygen. Sufficient oxygen concentration facilitated the formation of FeOOH or Fe2O3, while an oxygen-deficient environment favored the formation of Fe3O4.

Morphological characteristics of low-asphalt RAP and influence of its reaction product during combustion heating on regenerated asphalt

To provide reference for regeneration of the finely separated low-asphalt reclaimed asphalt pavement (RAP), the macroscopic and microscopic laboratory testing and quantum chemical simulation were combined. The morphological characteristics of the basalt and limestone low-asphalt RAP were analyzed. The low-asphalt RAP needs to be dried before regeneration, so the reaction mechanism and product of the asphalt film on its surface during drying were clarified. The product influence on the temperature resistance and fatigue performance of the virgin asphalt was studied, so as to consider their mixing during the subsequent regeneration process. Result shows that the gradation of limestone low-asphalt RAP is coarser and particles are slenderer than basalt with the same particle size grade. The 5–10 mm low-asphalt RAP particles are slenderer than those in the 10–20 mm grade. In the drying cylinder, asphalt basically generate no new functional groups below 200℃, while the asphalt film on the low-asphalt RAP surface undergoes pyrolysis to produce carbon black with the particle size around 100μm in the combustion heating area. The most easily oxidation or pyrolysis site in asphalt molecule is the carbon atom connected to the benzene ring. The pyrolysis of asphalt molecules to generate free radicals in the local oxygen deficient environment is the prerequisite for the carbon black formation, and pyrolysis requires higher temperature than oxidation because of its higher energy barrier. As the carbon black content increases, the penetration and ductility of asphalt decrease, the softening point increases, the high-temperature performance is enhanced, the low-temperature performance is weakened, and the fatigue performance is not significantly affected. As the particle size of carbon black increases, the decrease range in penetration, ductility and low-temperature performance of asphalt declines, the increase or improvement range of softening point and high-temperature performance enhanced, while the fatigue performance still shows no significant and regular change.

Air infiltration characteristics in oxygen-enhanced and heated chambers on the Qinghai-Xizang Plateau

The Qinghai-Xizang Plateau is characterized by a low-pressure and oxygen-deficient environment due to its high altitude, causing discomfort and major safety problems for the inhabitants. To address this, oxygen-enriched chambers can be used to alleviate the plateau reaction. However, little consideration has been given to air infiltration in these chambers, with a lack of information on the corresponding infiltration heat loss phenomenon. This paper addresses this by investigating the phenomenon of air flow in an oxygen-enriched chamber using experiments and simulations. The results highlight that when there is a difference in oxygen concentration between the interior and exterior of the chamber, mass transfer occurs due to both the molecular diffusion in addition to a flow due to the air density difference caused by the variation in concentration. Also, the simultaneous stack effect is roughly equivalent to 10 times the oxygen pressure, and the two pressure effects act in opposite directions. It is also noted that both the oxygen pressure and the stack effect decrease as the atmospheric pressure decreases. Overall, the oxygen-enriched chambers exhibit less infiltration in plateau areas with a low atmospheric pressure compared to plains areas with a relatively high atmospheric pressure. Finally, this study establishes formulas that can be used to calculate air infiltration rates in oxygen-enriched chambers. This study fills a gap in the existing literature regarding the air infiltration mechanism in oxygen-enriched chambers at high altitudes and low pressures, providing a theoretical foundation for improving indoor environments in the Qinghai-Xizang Plateau and other high-altitude regions.

Experimental study on combustion and thermoacoustic instability characteristics of ethanol/methane Co-firing flames

This paper investigates the combustion and thermoacoustic instability characteristics of ethanol/methane co-firing flames. Methane was introduced into the combustion chamber in three different mixing methods: the premixing method, single-tube injection, and dual-tube injection. The effects of mixing ratio, equivalence ratio, jet pipe diameter and position on combustion performance are also considered. The results show that under the premixed combustion mode, as the methane ratio increases, combustion instability shows a trend of first enhancement and then weakening, reaching a maximum pressure pulsation of 228.8 Pa at a 30 % mixing ratio. When methane is injected transversely into the combustion chamber using a single-tube or dual-tube, the inner diameter of the injection tube, injection height, and injection distance are essential factors affecting combustion instability, all of which will change the inhibitory effect of the transverse jet on instability. In addition, when the methane mixing ratio reaches 50 %, the co-firing flames will be in a relatively stable combustion state under all conditions. But at this time, the increase in flame temperature and the oxygen-deficient environment in the combustion chamber will cause simultaneous increases in CO and NOx emissions, which are not conducive to clean and efficient fuel combustion.

Unveiling the impact of Fe-doping concentration on the local structure and morphological evolution of Cr2O3 nanoparticles

A series of Cr2−xFexO3 (0.0 ≤ x ≤ 0.3) nanoparticles were successfully synthesized using a sol-gel-based method. Analysis through XRD and SAED of both pure and Fe-doped Cr2O3 nanoparticles revealed a rhombohedral structure belonging to the R3‾cD3d6 space group, without the formation of secondary phases or Fe clusters. Fe ions were well integrated, as indicated by fluctuations in lattice parameters, and lattice strain. The crystallite size decreased from 38.42 to 27.54 nm with increasing doping concentration. HRTEM images depicted evenly distributed nanoparticles. At lower dopant concentrations (x = 0.1), smaller and more heterogeneous nanorod-like structures emerged, with average sizes and lengths of 36.56 and 39 nm, respectively. Increasing the doping content to x = 0.2 resulted in a morphological shift towards semi-spherical and ellipsoidal shapes, with average dimensions of 22.84 and 31 nm, respectively. At higher doping levels (x = 0.3), nanoparticles grew to 66.5 nm in size and exhibited a spherical morphology. Raman and Fourier transform infrared spectra showed red-shifting of absorption bands with increasing Fe content, attributed to variations in bond length and Cr/Fe–O–Cr/Fe structural perturbation. XPS and Mössbauer spectroscopy analyses confirmed the oxidation states of Fe3+ and ionized oxygen vacancies in the crystal lattice of Cr2O3 nanoparticles. Higher values of quadrupolar splitting Δ indicated greater structural disorder induced by Fe3+ in octahedral positions and in an oxygen-deficient environment. Atomistic simulations confirmed that Fe3+ dopants can induce the presence of vacancy-complexes, forming a stable double-defect configuration with vacant Cr sites along the c-axis, proximal to oxygen vacancies with a single positive charge. These findings offer both experimental and theoretical insights into the dynamics of structural defects in trivalent transition metal doping of Cr2O3 nanoparticles, which holds significant implications for spintronics research.

Nano-scale corrosion mechanism of T91 steel in static lead-bismuth eutectic: A combined APT, EBSD, and STEM investigation

T91 steel is a candidate material for structural components in lead-bismuth-eutectic (LBE) cooled systems, for example fast reactors and solar power plants [1]. However, the corrosion mechanisms of T91 in LBE remain poorly understood. In this study, we have analysed the static corrosion of T91 in liquid LBE using a range of characterisation techniques at increasingly smaller scales. A unique pattern of liquid metal intrusion was observed that does not appear to correlate with the grain boundary network. Upon closer inspection, electron backscatter diffraction (EBSD) reveals a change in the morphology of grains at the LBE-exposed surface, suggesting a local phase transition. Energy dispersive X-ray (EDX) maps show that Cr is depleted in the T91 material near the LBE interface. Furthermore, we observed the dissolution of all Cr-enriched precipitates in this region. Although the corrosion is conducted in an oxygen deficient environment, both scanning transmission electron microscopy (STEM) and atom probe tomography (APT) reveal a thin surface oxide layer (presumably wüstite) at the LBE-steel interface. Using electron energy loss spectroscopy (EELS) in the STEM, as well as APT, the atomic scale elemental redistribution and 3D morphology of the corrosion interface is investigated. By combining results from these different techniques, several types of oxide phases and structures can be identified. Based on this detailed nano-scale information, we propose potential mechanisms of T91 corrosion in LBE.

Cold plasma treatment boosts barley germination and seedling vigor: Insights into soluble sugar, starch, and protein modifications

This study investigates the impact of three cold plasma treatments on barley seed germination: direct treatment of dry seeds (DDS), direct treatment of water-soaked seeds (DWS), and indirect treatment of seeds using plasma-activated water (IPAW). Our findings reveal that while DDS maintained the seed's imbibition structures, DWS significantly reduced water uptake. Notably, DWS-treated seeds exhibited a substantial increase in moisture content, potentially leading to an oxygen-deficient environment within the seed. This condition appeared to hinder germination, contrasting with the beneficial effects observed in DDS-treated seeds. Analyses of surface hydrophilicity, phenolic compounds, carbohydrate composition, protein storage and seedling growth were conducted. Interestingly, cold plasma treatment enhanced seed surface hydrophilicity, as evidenced by a decrease in water contact angles, particularly for DWS. We observed specific reductions in flavonoids and total phenolics, alongside shifts in carbohydrate composition, including increased sugar content up to 15.1% (DDS) and 13.5% (DWS), accompanied by a decrease in starch content to 189.00 ± 7.86 mg/g FM for DWS. Protein storage assessments revealed declines in albumin, globulin and prolamin fractions post-CP exposure. Finally, DDS and IPAW treatments markedly improved seedling shoot growth (from two to three-fold), underscoring the potential of these treatments in enhancing barley germination.

Petrophysical Insights Into Lunar Mafic Extrusive Basalts Over Reiner Gamma Formation

The enigmatic swirls of Reiner Gamma Formation (RGF) have been found to be associated with localized magnetic surges and high albedo markings. The intriguing diversity within deep-seated lithologies unravels the compositional evolution of the RGF soil, thereby providing new insights into the geological formation of lunar swirls. The present work contributes to the petrophysical significance of possible mafic units by utilizing the multisensor data from recent lunar missions. The compositional characterization of mafic-rich regolith facilitates an improved high-resolution eigenvector-based pyroxene spectroscopy. This provides evidence of endogenic magmatic water in the spectra of high Mg orthopyroxene with pronounced olivine content. Some regions in the western part contribute to the presence of chromium with the possible emplacement of mafic-rich basalts in the oxygen-deficient environment. The sensitivity of the radar echo to the petrographic units has been utilized to derive the physical characteristics of the regolith grains. The regions with enhanced hydration attribute to an increased dielectric permittivity with an associated surge in bulk density and circular polarization ratio. This is in concordance with the degree of maturity in the regolith due to space weathering. Moreover, a relatively compact confinement of the soil pattern has been observed in the immature mafic-rich patches, emphasizing the mechanical stability of the regolith. The regional geomorphology indicates the emanation of wrinkled ridges, wherein higher mafic abundance zone attributes to the primitive source of extruded magma. In essence, this study proposes the inclusion of local charged dust variant in the global formation perspective of the RGF.

Numerical investigation of different biomass feedstock on syngas production using steam gasification and thermodynamic analysis

Abstract Extensive research has been done to provide energy from renewable sources due to climate change, global warming and limited fossil resources. Due to its low energy density, biomass is one of the renewable energy sources that is not used directly. Biomass is a clean, renewable energy source with a zero carbon dioxide release rate. Gasification is a chemical process that converts carbonaceous materials like biomass into gaseous fuels or useful chemical raw materials for gasification to occur in an oxygen-deficient environment with a requirement for heat which needs mediators for the reaction, like air, oxygen, superheated steam, or a combination of these. This study has been conducted to investigate the impact of the type of biomass feed on the production of syngas using the steam gasification method. Therefore, rice husk, wood chip, wood residue, coffee bean and green waste are considered, and the impact of gasification temperature and steam to biomass ratio (S/B) is investigated. According to the results, wood residue produces the most hydrogen compared to other feeds. With the increase of gasification temperature, an increase-decrease trend in the mass flow rate of hydrogen and an increase trend in the mass flow rate of carbon monoxide can be seen. The hydrogen produced in wood residue is 855 kg/h at S/B of 0.2 as well as a gasification temperature of 1200 °C. The lowest mass flow rate of hydrogen and carbon monoxide is related to green waste feed.

Effect of Carrier Gas on the Gas Sensing Performance of Co1−2xNixMnxFe2−yCeyO4 Double-Substitution Spinel in Flammable Gases and Volatile Organic Compounds

The presence of high concentrations of flammable gases and volatile organic compounds in the atmosphere has been widely reported to be detrimental to human survival. A lot of research effort has been put toward finding an efficient means of quick detection of these gases below their ‘immediately dangerous to life or health’ concentrations. Detecting these gases in an oxygen-deficient environment is a crucial task to consider and has been overlooked. In this research, double-substitution spinel with the chemical formula Co1−2xNixMnxFe2−yCeyO4, where 0 ≤ x = y ≤ 0.3, was prepared via the glycol-thermal technique. The final products, following appropriate substitution, were CoFe2O4 (dried naturally), CoFe2O4 (dried with infrared lamp), Co0.8Ni0.1Mn0.1Fe1.9Ce0.1O4, Co0.6Ni0.2Mn0.2Fe1.8Ce0.2O4 and Co0.4Ni0.3Mn0.3Fe1.7Ce0.3O4 spinel ferrites. The X-ray diffractometry (XRD), high-resolution transmission electron micrographs (HRTEM) and X-ray photoelectron spectroscopy (XPS) of the samples confirmed the formation of the spinel. The gas sensing performance of these samples was tested at the operating temperature of 225 °C toward liquefied petroleum gas (LPG), ammonia, ethanol and propanol. The Co0.8Ni0.1Mn0.1Fe1.9Ce0.1O4-based sensor was selective to LPG, with a high response of 116.43 toward 6000 ppm of LPG when helium was used as the carrier gas, 3.35 when dry air was the carrier gas, 4.4 when nitrogen was the carrier gas, but it was not sensitive when argon was used as the carrier gas.

CDCA8 promotes bladder cancer survival by stabilizing HIF1α expression under hypoxia

Hypoxia is an essential hallmark of solid tumors and HIF1α is a central regulator of tumor cell adaptation and survival in the hypoxic environment. In this study, we explored the biological functions of cell cycle division-related gene 8 (CDCA8) in bladder cancer (BCa) cells in the hypoxic settings. Specifically, we found that CDCA8 was significantly upregulated in BCa cell lines and clinical samples and its expression was positively correlated with advanced BCa stage, grade, and poor overall survival (OS). The expression of CDCA8 proteins was required for BCa cells to survive in the hypoxic condition. Mechanistically, CDCA8 stabilizes HIF1α by competing with PTEN for AKT binding, consequently leading to PTEN displacement and activation of the AKT/GSK3β signaling cascade that stimulates HIF1α protein stability. Significantly, HIF1α proteins bind to CDCA8 promoter for transcriptional activation, forming a positive-feedback loop to sustain BCa tumor cells under oxygen-deficient environment. Together, we defined CDCA8 as a key regulator for BCa cells to sense and prevail oxygen deprivation and as a novel BCa therapeutic target.

Inflammation-related signaling pathways in tendinopathy.

Tendon is a connective tissue that produces movement by transmitting the force produced by muscle contraction to the bones. Most tendinopathy is caused by prolonged overloading of the tendon, leading to degenerative disease of the tendon. When overloaded, the oxygen demand of tenocytes increases, and the tendon structure is special and lacks blood supply, which makes it easier to form an oxygen-deficient environment in tenocytes. The production of reactive oxygen species due to hypoxia causes elevation of inflammatory markers in the tendon, including PGE2, IL-1β, and TNF-α. In the process of tendon healing, inflammation is also a necessary stage. The inflammatory environment formed by cytokines and various immune cells play an important role in the clearance of necrotic material, the proliferation of tenocytes, and the production of collagen fibers. However, excessive inflammation can lead to tendon adhesions and hinder tendon healing. Some important and diverse biological functions of the body originate from intercellular signal transduction, among which cytokine mediation is an important way of signal transduction. In particular, NF-κB, NLRP3, p38/MAPK, and signal transducer and activator of transcription 3, four common signaling pathways in tendinopathy inflammatory response, play a crucial role in the regulation and transcription of inflammatory factors. Therefore, summarizing the specific mechanisms of inflammatory signaling pathways in tendinopathy is of great significance for an in-depth understanding of the inflammatory response process and exploring how to inhibit the harmful part of the inflammatory response and promote the beneficial part to improve the healing effect of the tendon.

SiC/YAG composite coatings by a novel liquid fuelled high velocity oxy-fuel suspension thermal spray

Despite recent advances in suspension-based thermal spray techniques, there is still a need to widen the capability of available thermal spray setups to handle suspension to explore new compositions and improve the properties and performance of existing ones. In this work, a novel setup for injecting liquid-based feedstock in a liquid-fuelled high velocity oxy-fuel (HVOLF) thermal spray torch is proposed, involving a new hardware (“Hybrid Nozzle”) capable of injecting suspension radially and protecting the thermal spray flame from the environmental oxygen by inert gas shrouding. The new setup was used to deposit SiC/YAG composite coatings with 85 wt% SiC content, and their wear performance was evaluated. An oxygen deficient environment was provided to the HVOLF flame, ensuring that no or minimal (<2 wt%) SiO2 was formed in the coating during the spray, as confirmed by XRD. A good wear performance was observed at low load below 20 N, with a specific wear rate < 5 × 10−5 mm3/Nm, with the onset of wear mechanisms characteristic of ceramic wear in the brittle regime between 20 and 30 N. The future applicability of this novel setup to a range of oxidation- and heat-sensitive materials and composites offers the opportunity for new coating materials to be explored with suspension and solution precursor-based HVOLF thermal spray.

Biochar Application Increases the Amount of Nitrogen, Phosphorus and Potassium in the Soil: a Review

Biostimulants can be given to seeds, plants, and soil to encourage growth. Improved tolerance to abiotic stressors and higher seed and grain yields and quality results from these components altering critical and biochemical processes throughout plant development. The need for fertilizers can also be minimized because of biostimulants. Biochar is a biostimulant, a porous material with a high sorption capacity, which can be put directly into the soil with fertilizers. Biostimulants can be either naturally occurring or synthetically produced compounds that stimulate and activate the plant to resist stressful situations. When biomass is pyrolyzed in an oxygen-deficient environment, biochar is produced as a byproduct. It has a carbonaceous structure and several functional groups, making it permeable. Its molecular structure also demonstrates remarkable resistance to chemicals and microbes. The chemical and physical properties of biochar are very sensitive to the pyrolysis temperature and other process parameters, including residence time and furnace temperature.

Microstructure and tribological properties evolution of Ni–Mo–SrSO4 composites as a function of Mo contents at different temperatures

Ni–Mo–SrSO4 composites with different Mo amount were prepared by hot pressing in a vacuum. The oxygen-deficient environment derived from the degradation of SrSO4 during fabrication process led to the formation of SrMoO4, Sr2NiMoO6, and SrO in the sintered composites. With the increment in the contents of Mo, excessive dissolved Mo atoms accelerated the oxidation of Ni in the oxygen-deficient environment, which eradicated SrMoO4 phase. As compared to sintered material containing Sr2NiMoO6 and SrO, the appearance of SrMoO4 led to a distinct decrease in the density and microhardness. To reveal the effect of SrMoO4 on the wear mechanism, the tribological properties of the sintered composites against Al2O3 ball were investigated at different temperatures. The result indicated that the in-situ composite consisting of 80.75 wt.% Ni, 14.25 wt.% Mo, and 5 wt.% SrSO4 exhibited good friction and wear properties at room temperature (RT) and 800 °C, which was attributed to the development of the intact tribofilm with grooves consisting of SrMoO4, Sr2NiMoO6, NiO, and h-MoO3 at RT and the synergistic lubricating effect of SrMoO4, Sr2NiMoO6, and oxides (NiO, α-MoO3, SrMoO4, α-NiMoO4, and β-NiMoO4) at 800 °C.

Origin of Upper Cretaceous marine ironstones of Ayat Formation (Turgay depression, Northern Kazakhstan)

This work studies the mineralogical and geochemical features of ooidal ironstone formation of the Upper Cretaceous Ayat Formation located in the Turgay depression (Kazakhstan). The origin of ooidal ironstone deposits has been the subject of many discussions for a long time. These results present diagenetic conditions of the marine ironstone precipitation in the Ayat Formation. Various authigenic minerals, such as siderite, glauconite, goethite, pyrite, hydroxylapatite, wurtzite, and barite indicate fluctuations in the different geochemical conditions during the diagenesis of marine sediments of the Ayat Formation. The precipitation of in situ pyrite and wurtzite was controlled by an oxygen-deficient environment at the interface between water and sediment, which was accompanied by bacterial sulphate reduction under seabed conditions and, in consequence, by the concentration of sulfides. The authigenic assemblage of siderite, wurtzite, and barite indicates an integrated process of their input to site the sedimentation. The stable isotopic composition of siderite supports the microbial carbonate origin by decomposing the organic matter. However, geochemical features (the pattern Co/Zn vs (Co + Ni + Cu)) evidence the hydrogenous precipitation of iron. It involves the interaction of two central in situ processes to form Ayat ooidal ironstones. One of them is the iron precipitation from the bottom water, and the second is the microbial generation of hydrocarbons. Marine Ayat and channel Lisakovsk ironstones have similar features of bulk rock geochemistry. It reflects the exact environments of the ooidal iron ore formation, while the wall rocks have distinctive facies conditions.

Oxygen vacancy modified α-Fe2O3 nanorods provide an environment-friendly and efficient anti-corrosion passive film into polymer coating

Oxygen vacancy modified Fe2O3 (OV-Fe2O3) nanorods were fabricated and then used as epoxy coating fillers. The OV-Fe2O3 fillers passivates the steel substrate, because oxygen atoms can be stored in the vacancies to form a metastable state. Electrochemical impedance spectroscopy showed the impedance modulus of OV-Fe2O3 coatings was about 105 times higher than general α-Fe2O3 coatings after O2-high pressure and high-temperature corrosion. X-ray photoelectron spectroscopy and scanning vibrating electrode technique confirm OV-Fe2O3 can continuously transport oxygen from the oxygen-rich environment to the substrate surface (oxygen-deficient environment) before the permeation of the corrosive medium, eventually achieving efficient passivation.

Oxidative catalytic steam gasification of sugarcane bagasse for hydrogen rich syngas production

Reactive Flash Volatilization (RFV) is an emerging thermochemical method to produce tar free hydrogen rich syngas from waste biomass at relatively lower temperature (<900 °C) in a single stage catalytic reactor within a millisecond residence time. Here, we show catalytic RFV of bagasse using Ru, Rh, Pd, or Re promoted Ni/Al2O3 catalysts under steam rich and oxygen deficient environment. The optimum reaction conditions were found to be 800 °C, steam to carbon ratio = 1.7 and carbon to oxygen ratio = 0.6. Rh–Ni/Al2O3 performed the best, resulting in highest hydrogen concentration in the synthesis gas at 54.8%, with a corresponding yield of 106.4 g-H2/kg bagasse. A carbon conversion efficiency of 99.96% was achieved using Rh–Ni, followed by Ru–Ni, Pd–Ni, Re–Ni and mono metallic Ni catalyst in that order. Alkali and Alkaline Earth Metal species present in the bagasse ash and char, that deposited on the catalyst, was found to enhance its activity and stability. The hydrogen yield from bagasse was higher than previously reported woody biomass and comparable to the microalgae.

Near-Infrared Emission Material with Superlong Afterglow Performance and Its Multifunctional Applications.

A new near-infrared (NIR) emission material, BaSi1.5Ge2.5O9:Cr3+, with outstanding long afterglow properties is designed and synthesized successfully. Its structure, photoluminescence, and long afterglow emission features are studied in detail. Cr3+ occupies six-coordinated Ba2+ and Ge4+ sites in this system, which can emit characteristic broadband NIR light in the range of 700-1200 nm, and it has a long afterglow emission of more than 10 h. We calculated the band gap of the host at about 4.1 eV, the energy level distribution after Cr3+ doping, and the distribution of oxygen vacancies through density functional theory simulation, which theoretically proved the characteristic transition of Cr3+ and that the oxygen vacancies are crucial to form the defect energy levels. This is corroborated with the reflectance spectra, three-dimensional thermoluminescence spectra, and electron spin resonance (ESR) spectra. The oxygen-deficient environment favors the formation of oxygen vacancy defects and prevents the oxidation of Cr3+ to Cr6+, which are the key points for the luminescence and afterglow properties. A mechanistic model of defect formation and electron trapping and transport processes is successfully established. Finally, its multifunctional applications in information anticounterfeiting encryption, biological tissue penetration, and internal nondestructive testing and imaging are demonstrated.

Metabolite profiling of leaves of three &lt;i&gt;Epilobium&lt;/i&gt; species

BACKGROUND: The ability of plants to adapt to oxygen deficiency is associated with the presence of various adaptations, many of which are mediated by significant changes of metabolism. These changes allow resistant wetland plants to grow even in oxygen-deficient environment.&#x0D; AIM: The aim of the study was to carry out metabolic profiling of the leaves of the wetland species Epilobium palustre and Epilobium hirsutum, and the mesophyte species Epilobium angustifolium in order to identify the most characteristic metabolome traits of hypoxia-resistant plants.&#x0D; MATERIALS AND METHODS: Metabolite profiling was performed by GC-MS. Statistical analysis of metabolomics data was processed using R 4.2.1 Funny-Looking Kid.&#x0D; RESULTS: The resulting profile included about 360 compounds. 70 of these were identified and 50 compounds were determined to a class. Sugars (64) were the most widely represented in the obtained profiles. 16 amino and 20 carboxylic acids, lipids and secondary compounds have been identified. Significant differences were revealed between the profiles of leaf metabolomes of mesophyte E. angustifolium and hydrophytes E. hirsutum and E. palustre. The mesophyte was characterized by high levels of sugars. The metabolomes of wetland Epilobium species practically did not differ from each other and were characterized by the accumulation of amino acids, including GABA shunt intermediates, dicarboxylic acids of the Krebs cycle, and metabolites of glycolysis and lactic acid fermentation, which reflects the stimulation of anaerobic respiration, nitrogen metabolism, and alternative pathways of NAD(P)H reoxidation in wetland plants.&#x0D; CONCLUSIONS: Traits of metabolic profiles detected in hydrophyte Epilobium species can be used to assess the degree of plant resistance to oxygen deficiency.