High-temperature Treatment Research Articles

Atomistic insights into formaldehyde (HCHO) high-temperature treatment and syngas production via ReaxFF MD simulations

Formaldehyde (HCHO), typically known as an industrial waste gas, can be recycled to generate syngas. Our study focuses on the high-temperature and high-pressure treatment of formaldehyde, including pyrolysis, oxidation, and supercritical H2O/CO2 (scH2O/scCO2) co-pyrolysis via reactive molecular dynamics. Results showed that in the pyrolysis, the primary final products are H2 and CO. The formation of CO occurs through the double dehydrogenation of HCHO, and H-abstraction reaction leads to the formation of H2. In the oxidation, scH2O and scCO2 co-pyrolysis systems, the corresponding global reactions vary. HCHO can be oxidized to HCOOH, ultimately producing CO2. Another pathway for CO2 generation involves the formation of the COOH radical from CO. Oxidative treatment is more powerful in handling formaldehyde pollutants, while the supercritical condition is more effective in producing syngas. The order of carbon emission is oxidation>scH2O>pyrolysis. In the scCO2 system, scCO2 participates in the reaction, increasing CO production. Moreover, reaction kinetics models are proposed and agree well with experimental results. Under high-temperature conditions, the reaction rate in the oxidation system is the highest. Based on the activation energy for formaldehyde consumption and the energy barriers of the sub-reactions, the pyrolysis process is the easiest, whereas the oxidation process is the most difficult.

Effects of fasting on the interplay between temperature and Trypanosoma cruzi infection on the life cycle of the Chagas disease vector Rhodnius prolixus.

Rhodnius prolixus, a triatomine insect, is one of the most important vectors of Chagas disease in South America. Its interaction with the parasite Trypanosoma cruzi, the causative agent of this disease, is known to be deeply affected by ambient temperature and the nutritional status of the insect vector. In this study, we investigated how starvation affects the life cycle of R. prolixus and the population dynamics of the parasite inside the intestine of the vector at four temperatures ranging from 24°C to 30°C. The weights and molting times of chronically infected and uninfected insects were monitored through repeated 30-day fasting periods from first instar to adult stage, assessing their capacity to retain blood meal weight between developmental stages and tracking parasite concentrations in their urine. Our results demonstrate that ambient temperature is a crucial factor affecting the resistance of R. prolixus to starvation, as survival, body weight, and weight retention greatly decreased in high temperature treatments. Furthermore, we showed that temperature significantly influenced whether T. cruzi established an infection in early instars, with few insects developing infections at the lowest and highest temperature treatments. Additionally, we discovered that a fasting period of 30 days induces a steady decrease in parasite populations in the vector over its lifetime. Infection by T. cruzi had no effect on the survival, molting time, and nutritional factors monitored in our protocol. Our results highlight the importance of nutrition as a determining factor for the development of the vector and the parasite, providing valuable insights for elucidating the complex interplay between temperature and nutrition in shaping the epidemiology of Chagas disease in a changing climate.

Enhancing quality and strength of recycled coarse and fine aggregates through high-temperature and ball milling treatments: mechanisms and cost-effective solutions

Enhancing quality and strength of recycled coarse and fine aggregates through high-temperature and ball milling treatments: mechanisms and cost-effective solutions

Study on Low-Temperature Deposition of Diamond-like Carbon Film on the Surface of Bionic Joint Thread and Its Properties

The double-connection structure of bionic joints of mining drill pipes has solved the problem of drill drop caused by fatigue cracks. However, with low-melting-point elastic–ductile alloy filling in the bionic joint, the thread on the joint cannot be hardened by high-temperature surface hardening treatments such as quenching and nitriding, making it prone to thread gluing or excessive wear. In this paper, the feasibility of diamond-like film deposition on the surface of a bionic drill pipe thread was studied. A tungsten transition film was used to improve the thickness of the film and the interfacial bond strength between the film and the substrate. The test results show that the total thickness of the DLC film is about 3~5 μm, the roughness is less than 2 μm, the hardness of the film reaches 24.4 GPa, the friction coefficient is 0.04, and the critical load is 56 N. SEM and EDS analyses show that the tungsten film and the bionic joint thread form a metallurgical structure. The morphology of the diamond-like carbon film is uniform and dense, and there is no obvious stratification between the substrate material. The joint with a diamond-like coating treatment has a longer service life than joints receiving conventional high-temperature nitriding treatment.

OBTAINING OF GARNET CERAMIC MATERIALS BY UTILIZATION OF RICE HUSK ASH AS SILICA SOURCE

The current research aims at the obtaining of new type pigments from the garnet mineral group by utilizationof rice husk ash as silica source (RHA). At the beginning, the mixtures prepared from the starting raw materials areground in a ball mill and then subjected to high temperature treatment. Green pigments were synthesized at twotemperatures: 1000°C and 1100°C. Using the tintometer RT 100 Lovibond the colour characteristics were measuredspectrophotometrically. The rice husk ash was investigated using scanning electron microscopy. The conducted hot-stage microscopic studies show that the pigments remain thermally stable when heated. The highest fire resistance - upto temperatures of 1380°C - 1400°C show the uvarovite pigments with main phase 3CaO.Cr2O3.3SiO2 or by a generalformula Ca3Cr2[SiO4 ]3. They are suitable for inserting into ceramic glazes without danger of decomposition or reaction.Keywords: ceramic pigments, SEM, colour determination, Hot-stage microscopy.

Luminescence Patterns on Multimillimeter Single-Crystal MAPbBr3 Microplatelets via Thermal Ablation Effects.

The single crystal distinguishes itself as the most outstanding representative of excellent optoelectronic performance among perovskite semiconductors due to its exceptional charge carrier properties, extraordinary optophysics, precise structural geometries, and superior material stabilities. However, it exhibits mediocre performance in light emission, which can be attributed to its excessive carrier diffusion lengths and extremely low recombination rates. To address this challenge, this study puts forward a controllable high-temperature annealing treatment strategy concentrating on multimillimeter-scale MAPbBr3 micrometer-thick platelet single crystals (MPSCs). Through the utilization of thermal ablation effects to convert the surface monocrystalline lattices into polycrystalline perovskite nanocrystals (PNCs) with a remarkably increased specific surface area, the fluorescence intensity arising from the rapid recombination of free carriers on the PNC surface is enhanced by 320 times compared to the pristine MPSC surface. These PNCs produced through surface annealing, with the characteristic of loose adhesion to surfaces, can be mechanically wiped away and regenerated in situ via reannealing the residual MAPbBr3 MPSCs, guaranteeing high intensity, durability, and standard geometric fluorescence. Moreover, by regulating the surface distributions of thermal ablation effects and carrying out embossing annealing treatment or laser direct writing, we can design and fabricate relatively complex, high-contrast (255×), and clearly resolved fluorescence patterns on MPSC surfaces.

Study of the effect of CdCl2 introduction on the high temperature activation treatment of CdTe:As polycrystalline thin films

V-doped CdTe polycrystalline films can achieve both doping activation and defect passivation by high-temperature CdCl2 heat treatment, but this requires simultaneous modulation of the amount of CdCl2 introduced to obtain high-quality films. It is found that increasing the CdCl2 introduction does not change the physical phase structure and lattice constant of CdTe:As thin films, but promotes grain recrystallisation, and can promote the formation of A-center, and inhibit the formation of Cd vacancy (VCd) defects, as well as the formation of deep energy level defects. The results provide guidance for the improvement of high-temperature CdCl2 heat treatment of V-doped CdTe polycrystalline thin films.

Effect of temperature on the radon release characteristics of red clay

Bricks and tiles crafted from fired red clay are extensively utilized in everyday construction activities. However, red clay inherently contains radon gas, a radioactive substance that could potentially endanger human health. Hence, investigating the radon emission patterns of red clay post high-temperature treatment holds significant importance. This study examines the pore structure of red clay following high-temperature treatment through nitrogen adsorption and analyzes the radon release patterns. Findings reveal that the radon release rate from red clay initially rises, then declines with increasing temperature, peaking at 200 °C, registering at 0.0127 Bq/(m2 s). The pore structure significantly influences radon exhalation, with connectivity and micropore volume demonstrating linear correlations with radon exhalation rate, with correlation coefficients of 0.96 and 0.78, respectively. This research offers valuable insights into radon radiation in structures made of red clay.

Establishment of a novel prime editing system by introducing the reverse transcriptase Tf1 combined with high-temperature treatment in rice

Establishment of a novel prime editing system by introducing the reverse transcriptase Tf1 combined with high-temperature treatment in rice

Hierarchical Assembly of Ternary MOF-Derived Sandwich Composites for High-Efficiency Tunable Electromagnetic Wave Absorption.

The proliferation of electronic devices drives the adoption of electromagnetic wave (EMW) absorbing materials to mitigate electromagnetic pollution. Metal-organic frameworks (MOFs) reveal great potential in EMW absorption field due to their unique pore structure and outstanding physicochemical properties. However, single MOFs are difficult to achieve both efficient absorption and wide frequency coverage owing to the limited electromagnetic properties and structural composition. Herein, a sandwich-like ternary MOF composite is successfully synthesized through a hierarchical assembly strategy. Following high-temperature treatment, the materials are converted into nitrogen-doped porous carbon with magnetic metals, non-magnetic metal oxides, and carbon nanotubes on the surface (labeled as TiO2/C@Co/N/C@CNT). The unique sandwich structure of the resulting derivatives provides a multi-level microstructure and multi-component synergistic effects, significantly enhancing electromagnetic wave absorption capabilities and broadening the effective absorption bandwidth (EAB). At 1.8 mm matching thicknesses, the material achieves a reflection loss of -56.3 dB and a 6.6 GHz EAB. Adjusting the matching thicknesses to 2.3 and 3.1 mm extends the EAB to 6.1-18 GHz, with absorption peaks of -47.6 and -47.1 dB. This work offers a novel guidance for constructing advanced MOF-derived materials with ultra-broadband EAB and strong EMW absorption through meticulous structural design and multiple components combination.

Thermally conductive, mechanically robust alumina-incorporated polyurethane films prepared by ultraviolet light curing

Abstract The development of heat dissipating composite materials for electronic systems can be expedited using alumina particles as modifiable polymer-matrix fillers. However, these composites are difficult to synthesize given the tradeoffs between thermal conductivity, insulating characteristics, and conduciveness to processing. To that end, the present study is focused on synthesizing environmentally friendly polyurethane films that could be cured by ultraviolet light within minutes, without requiring high-temperature heat treatment. Through the optimization of alumina modification, hybridization of thermally conductive fillers, filler content, and stirring time on the thermal conductivity of the polyurethane composites, this study improves the process for sustainability, low-cost, and convenient preparation. The experimental results confirmed that the use of surface modification and hybrid fillers is effective for enhancing the thermal conductivity, with the value of the polyurethane integrated with 50 wt% Al2O3 and 5 wt% Al2O3–poly (catechol/polyamine) being 76.40 wt% higher than that of pure PU (0.44 W/mK). Additionally, the use of hybrid fillers resulted in superior mechanical and thermal properties (such as tensile strain, tensile strength, thermal expansion coefficient, and temperature resistance) compared with those of pure PU and films incorporated with only a single filler.

3D printing of aligned silk fibroin microfibers covered with nitrogen-doped carbon dots for anti-counterfeiting

Counterfeiting has serious economic and social consequences, prompting researchers worldwide to develop innovative and highly secure anti-counterfeiting methods, including the use of various polymer printing techniques and the integration of functional materials to create patterns with customized designs that are easy to detect and cannot be falsified. Composite inks made of silk fibroin microfibers and polyvinyl alcohol or polyethylene glycol were developed to produce patterns with the microstructures aligned in the direction of extrusion during the 3D printing process. Fibroin microfibers were obtained via high temperature treatment and used as a precursor for carbon dot synthesis. This approach allowed the microfiber structure to be maintained and be amenable to the synthesis of carbon dots doped with N-heteroatom on its surface, resulting in a material that fluoresces bright blue when irradiated at 365 nm but remains invisible in normal lighting conditions.

Graphite Made from Coal by High-Temperature Treatment: An Insight into the Nanometric Carbon Structural Evolution

Graphite made from coal will not only widen the graphite mineral resource, but also significantly improve the value of coal utilization. In this study, anthracite coal was heated in the temperature range of 500 to 2900 °C to study the size increase of nanometric graphite crystallites from anthracite to real graphite. The carbon content rapidly increases to 99.2% when heated from room temperature to 1600 °C, and then gradually increases to 100% when the treated temperature increases to 2900 °C. The FTIR results show that methyl, methylene, and aromatic hydrocarbon, preexisting in the raw anthracite, were preserved in the JZS-500 sample, but that when the treated temperature ≥ 1000 °C, these C-H bonds almost disappear. The basic structural units (nano graphitic carbon) grow into distorted columns, and the basic structural units and micro-columns re-oriented and coalesced to form local molecular oriented domains with the temperature increase from anthracite to JZS-1500. When the temperature ≥ 1600 °C, amorphous carbon, onion-like carbon, turbostratic layers, and graphitic carbon co-occur within the graphitized coals. At the sub-micron scale, carbonization is a homogenous process, whereas graphitization is a heterogenous process. The average graphite crystalline size (La, lateral extension; Lc, stacking height) rapidly increases as the treatment temperature increases from 1600 to 2300 °C. Three coal structural transformation stages were classified according to the nanometric carbon structural evolution with temperature. This study will contribute to the efficient and value-added utilization of coal to make graphite materials.

Comparative Analysis of Pretreatment Methods for Fruit Waste Valorization in Euglena gracilis Cultivation: Impacts on Biomass, β-1,3-Glucan Production, and Photosynthetic Efficiency.

This study explored the sustainable valorization of fruit waste extracts from sugarcane bagasse (SB), banana peel (BP), and watermelon rind (WR) for Euglena gracilis biomass and β-1,3-glucan production. The extracts were prepared using water extraction (WE), high-temperature and pressure treatment (HTP), and dilute sulfuric acid treatment (DSA). The DSA-treated extracts consistently yielded the best results. E. gracilis cultured in SB-DSA showed the highest cell density with a 2.08-fold increase compared to the commercial HUT medium, followed by BP-DSA (1.35-fold) and WR-DSA (1.70-fold). Photosynthetic pigment production increased significantly, with chlorophyll a yield being highest in SB-DSA (1.90-fold increase). The chlorophyll a/b ratio and total carotenoid content also improved, indicating enhanced light-harvesting capacity and photoprotection. Photosynthetic efficiency, measured by chlorophyll fluorescence, notably improved. The maximum quantum yield of PSII (Fv/Fm) increased by up to 25.88% in SB-DSA, suggesting reduced stress and improved overall photosynthetic health. The potential photochemical efficiency (Fv/F0) showed even greater improvements: up to 40.53% in SB-DSA. Cell morphology analysis revealed larger cell aspect ratios, implying a more active cellular physiological state. β-1,3-glucan yield also increased by 23.99%, 12.92%, and 23.38% in SB-DSA, BP-DSA, and WR-DSA, respectively. This study demonstrates the potential of pretreated fruit waste as a cost-effective and sustainable medium for E. gracilis cultivation, offering the dual benefits of waste valorization and high-value compound production. These findings contribute to the development of more efficient biorefinery processes and align with the circular economy principles in food biotechnology.

Incorporation of SnSe2/SnO2 heterostructures in carbon nanotubes for excellent lithium storage performance

As a new type of negative electrode material, tin-based material exhibits a high theoretical capacity. However, tin-based anode materials always undergo severe volume change upon alloying reaction during lithium insertion and extraction, which leads to the pulverization of the active materials and poor electrochemical performance, seriously hampering its practical application. In this work, oxygen-containing group functionalized carbon nanotubes (FCNTs) were facilely obtained, and the three-dimensional crosslinked SnSe2-SnO2@FCNTs multiphase materials were prepared by solvothermal and high-temperature heat treatment. The formation of Sn-O-C bonds from oxygen-containing functional groups of FCNTs combined with Sn can promote the electric connection and integrity of the composites. The implanted defects in FCNTs can not only be beneficial to anchoring SnO2 and SnSe2 nanoparticles, but also helpful to the penetration of Li+ ions into the electrodes from electrolyte. In addition, the large Fermi energy difference between SnSe2 and SnO2 nanoparticles results in the formation of a built-in electric field at the interface of the multiphase materials, accelerating the diffusion of ions. The smaller size of the multiphase materials leads to significant pseudocapacitive behavior, which facilitates the highly reversible surface/interface adsorption. Under the multiple effects of FCNTs, SnSe2, and SnO2, the SnSe2-SnO2@FCNTs multiphase materials exhibited excellent electrochemical performance. At a current density of 0.1 A·g−1, a discharge specific capacity of 898.0 mA h·g−1 was achieved. When the current density was increased to 2 A·g−1, it still exhibited a discharge specific capacity of 443.9 mA h·g−1. After a long charge/discharge cycling at 1 A·g−1 over 450 cycles, it still showed a specific capacity of ∼ 400 mA h·g−1. This work significantly demonstrated the enhanced Li-storage performance of SnSe2-SnO2 heterostructures incorporated in the functionalized multi-walled CNTs. This opens a new way to synthesize advanced tin-based materials as high-performance anodes for high-energy density lithium-ion batteries.

Repeated High-Temperature Treatment Can Increase Prime Editing Efficiency in Dicot Model Species

Repeated High-Temperature Treatment Can Increase Prime Editing Efficiency in Dicot Model Species

Multiple Omics Analyses Reveal Activation of Nitrogen Metabolism and Flavonoid Glycosylation in Toxicodendron vernicifluum Under High Temperature

Lacquer trees (Toxicodendron vernicifluum), economically vital, face high-temperature stress in summer. Transcriptomic, proteomic, and metabolomic analyses were employed to investigate the mechanisms by which lacquer trees respond to high temperatures. High-temperature treatment led to notable metabolite changes with 224 upregulated and 69 downregulated. Indole-3-acetic acid remained stable while abscisic acid decreased, with increases in jasmonic acid and jasmonoyl-L-isoleucine indicating complex hormonal responses. JAR1 and ABA 8′-hydroxylase encoding genes were upregulated. The rise in JAs boosted the alkaloid content and activated nitrogen transport. High temperatures also increased specific amino acids and upregulated aminotransferase and protease-encoding genes. Metabolomic analysis showed elevated flavonoid glycosides and the upregulation of glycosyltransferase genes. WPCNA found 35 protein modules involved in secondary metabolite biosynthesis, protein phosphorylation, and signal transduction. Protein–protein interaction analysis revealed MYC6’s link with flavonoid biosynthesis, indicating its role in promoting flavonoids.

Copper single atoms decorated iridium nanoparticles for the selective hydrogenation of bromonitrobenzene

The interaction between metals is an important factor to modify the catalytic roles of metallic catalysts, and it is highly desirable to reveal the relationship between metal-metal interaction and catalytic performance. Three types of Ir-Cu catalysts including Cu single atoms modified Ir nanoparticles and Ir-Cu alloy catalysts are prepared to observe the modifying role of Cu on Ir. Under relatively high temperature treatment, Ir-Cu alloy can be produced from Cu single atoms and Ir nanoparticles. The selectivity to bromoaniline (BAN) over Cu/C-Ir catalyst can be up to 99.9 % at the 100 % conversion of bromonitrobenzene (BNB), which is higher than that over Ir/C (94.3 %) and Ir-Cu/C alloy catalyst (98.5 %). The turnover frequencies (TOFs) of Cu/C-Ir catalysts are evidently lower than that of the Ir-Cu/C alloy catalyst, though their dispersions are higher than that of Ir-Cu/C alloy catalyst. The electronic transfer from Cu single atoms to Ir nanoparticles not only weakens the hydrogen adsorption ability but reduces the number of active sites available for splitting hydrogen molecules into hydrogen atoms, leading to a decrease in the catalytic activity for the selective hydrogenation of BNB. The interaction exerted by unalloyed Cu single atoms on Ir nanoparticles differs from that of alloyed Cu on Ir, which may be the possible reason for the different catalytic performance between Cu single atoms modified Ir nanoparticles and Ir-Cu alloy.

Strong Metal-Support Interaction Triggered by Molten Salts.

Strong metal-support interaction (SMSI) plays a vital role in tuning the geometric and electronic structures of metal species. Generally, a high-temperature treatment (>500 °C) in reducing atmosphere is required for constructing SMSI, which may induce the sintering of metal species. Herein, we use molten salts as the reaction media to trigger the formation of high-intensity SMSI at reduced temperatures. The strong ionic polarization of the molten salt promotes the breakage of Ti-O bonds in the TiO2 support, and hence decreases the energy barrier for the formation of interfacial bonds. Consequently, a high-intensity SMSI state is achieved in TiO2 supported Ir nanoclusters, evidenced by a large number of Ir-Ti bonds at the interface, at a low temperature of 350 °C. Moreover, this method is applicable for triggering SMSI in various supported metal catalysts with different oxide supports including CeO2 and SnO2. This newly developed SMSI construction methodology opens a new avenue and holds significant potential for engineering advanced supported metal catalysts toward a broad range of applications.

Assessment of heat tolerance and identification of miRNAs during high-temperature response in grapevine.

With global warming, heat stress has been recognized as a significant factor limiting grapevine development and fruit quality. MicroRNAs (miRNAs) are a class of small non-coding RNAs known to play crucial regulatory roles in stress resistance. Hence, there is an immediate requirement to cultivate and identify grapevine varieties that are resistant to heat and explore miRNA-mediated heat stress defense mechanisms. In this study, we assessed the thermal resistance of 38 grape germplasm resources and identified a series of miRNAs involved in heat stress resistance. The CK (25°C) and HS (45°C) groups of "Shenyue" cuttings of grapes were used as experimental materials for next-generation sequencing and construct libraries of small RNAs. A total of 177 known and 20 novel miRNAs were detected in the libraries. Differential expression analysis identified 65 differentially expressed miRNAs (DEMs) using the DE-Seq procedure. Furthermore, RT-qPCR validation confirmed complementary expression profiles of eight DEMs and their target genes between the HS and CK groups. Heterologous transformation further identified the function of Vvi-miR3633a downregulated under heat stress in Arabidopsis. In the heterologous expression lines, the survival rate was reduced by high temperature treatment indicating the ability of Vvi-miR3633a to regulate heat resistance. Assessing the heat resistance of grape species and the expression patterns of miRNA in response to high temperatures may reveal the molecular processes of heat resistance regulation mediated by miRNA in grapes under heat stress.