Search

The tribological behavior and microscopic morphology of Cr2O3-TiO2 thin films produced by magnetron sputtering are thoroughly examined in this work. A thorough analysis was conducted to determine how various Ar: O2 flow ratios (80:20, 85:15, 90:10 and 95:5) affected the films microstructure, mechanical characteristics and tribological performance. Various characterization techniques, including scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and ball-on-disk wear testing, were employed to examine the microstructural features that contributed to the films' mechanical durability. The results indicated a clear correlation between the gas flow ratio and tribological properties. Specifically, the thin films deposited at an Ar: O2 ratio of 85:15 exhibited the best tribological performance, with a notably lower friction coefficient (0.41) and superior wear resistance (wear rate 4.3 × 10− 6 mm³/N·m), making this ratio the optimal choice for achieving enhanced tribological behavior. The superior performance at this ratio is attributed to the formation of a denser and more refined microstructure, as observed in the cross-sectional and surface morphology analyses. These findings highlight the capability of magnetron sputtering to produce high-performance thin films through precise control of the Ar: O2 flow ratio. [ABSTRACT FROM AUTHOR]

Simple Summary: Largemouth bass (LMB) is economically important but highly sensitive to heat stress. Breeding heat-resistant LMB is of big significance in the face of global warming. However, there still lacks an applicable method to efficiently assess the heat resistance of LMB individuals. In this study, we developed a tiered exposure method where the temperature was increased step-wise and the heat resistance of fish was quantified as the lethal cumulative temperature (LCT). Largemouth bass juveniles could be classified as sensitive or resistant to heat stress based on the LCT measurements. Higher degrees of tissue damage and cell apoptosis were found in the livers of the heat-sensitive individuals. Differential expressions of genes involved in the endoplasmic reticulum stress response and apoptosis were also detected in the livers of sensitive and resistant fish. Additionally, LMB juveniles were found to be more resistant than adults and extremely heat-resistant individuals were successfully selected using the tiered heat exposure method. Our method and data are valuable for understanding the thermal biology of LMB and breeding heat-resistant LMB varieties. Largemouth bass (LMB, Micropterus salmoides), a commercially important farmed fish, is vulnerable to heat stress. Breeding heat-resistant LMB is highly desirable in the face of global warming. However, we still lack an efficient method to assess the heat resistance of LMB. In this study, the critical thermal maximum (CTmax) and static exposure methods were first performed to assess the heat resistance of LMB juveniles. The CTmax values of the experimental fish (average body weight 9.87 ± 3.14 g) ranged from 39 to 40 °C but were too close together to differentiate the individual heat resistance. Static exposure experiments with varying temperatures and fish groups also did not provide a clear method for determining the heat resistance. To address these limitations, we developed a tiered exposure method, where the temperature was increased step-wise, starting from 28 to 34 °C at 2 °C increments and then at 0.5 °C increments above 34 °C, with each step lasting one day. The heat resistance of the fish was quantified as the lethal cumulative temperature (LCT), allowing for the classification of fish as sensitive or resistant to heat stress based on their LCT values. To correlate the changes in tissue structure and gene expression with the heat resistance, a new batch of LMB juveniles (average body weight 23.66 ± 6.98 g) were subjected to tiered heat exposure. Brain and liver tissues were collected from the control (without heat exposure), resistant and sensitive (still alive but demonstrated abnormal symptoms) individuals when the temperature was maintained at 35.5 °C for 24 h. The liver tissues of the heat-sensitive individuals showed significant damage and increased cell apoptosis (p < 0.05) relative to those of the resistant ones. The ddit3/chop, bax and casp3 genes demonstrated differential expressions in the liver of the sensitive and resistant fish. Additionally, the LMB juveniles (average body weight 84.06 ± 20.95 g) were found to be more heat resistant than the adults from different sources (average body weight 364.29 ± 84.43 g and 545.71 ± 184.56 g). Through the tiered exposure method, extremely heat-resistant individuals were successfully selected from the population (average body weight 22.69 ± 6.89 g). These findings provide valuable insights into the thermal biology of LMB and the potential for breeding heat-resistant LMB varieties. [ABSTRACT FROM AUTHOR]

This article conducted on-site experiments on improving river sediment to produce planting soil, using aerobic composting technology. The main composting parameters include carbon nitrogen ratio, moisture content, pH value, and temperature. In order to adjust the carbon nitrogen ratio of the sediment, auxiliary materials such as chicken manure, pig manure, rice straw, and wheat straw can be added according to the carbon nitrogen ratio of the sediment itself and relevant specifications. In this article, rice straw and rice husk are added. In the on-site test, a group of piles were maintained above 60 ℃for 3 days, achieving harmless treatment of the sediment. However, when the carbon nitrogen ratio of the pile is less than 20, it is difficult for the sediment temperature to reach 60 ℃, and it cannot be guaranteed that the sediment can achieve harmless treatment. After the improvement, the obstacle factors of the sediment have been reduced, meeting the standard requirements. Nutrients increased, and among the 36 indicators after sediment improvement, only nitrogen was below the standard limit, while potassium and magnesium exceeded the standard limit. All other indicators met the standard requirements.

A novel Mn2+ doped ScTaO4 phosphor was synthesized through a high temperature solid state method and its photoluminescence properties were systematically investigated. The ScTaO4:Mn2+ phosphor exhibited two emission bands centered at 478 nm and 661 nm under UV excitation, attributed to the self-activated emission of the host and the 4T1 → 6A1 transition emission from doped Mn2+ ions, respectively. Through optimizing the concentration of doped Mn2+ ions, white light emission was achieved. Meanwhile, the temperature-dependent luminescence spectra of the ScTaO4:Mn2+ phosphor (in the range from 298 K to 523 K) revealed significantly different thermal quenching behaviors between the host and Mn2+ ions, which cause a notable change in the fluorescence intensity ratio of the host versus Mn2+ ions and enable high absolute and relative sensitivities, with maximum values of 0.0172 K−1 and 2.1% K−1 at 523 K, respectively. The results indicated that the as-prepared STO:Mn2+ phosphor can be a potential candidate material for high temperature optical thermometry. [ABSTRACT FROM AUTHOR]

Safety concerns associated with lithium batteries suggest the development of solid-state batteries as a promising variant. In this work, we doped a lithium boracite (Li4B7O12Cl) with Mg2+ to modify the Li+ sites and observed significant improvement in ionic conductivity by two orders of magnitude (from 3.03 × 10−7 S cm−1 to 2.81 × 10−5 S cm−1 at room temperature). We attribute the enhanced ion conductivity to the artificially induced Li vacancies resulting from Mg doping. The as-fabricated symmetrical battery (Li‖Li3.6Mg0.2B7O12Cl‖Li) exhibited good cycling performance with a stable voltage output even after 60 hours of cycling. The battery showed a coulombic efficiency retention of ∼99.7% after the cycling test. Our work demonstrates that Li4B7O12Cl is a superior solid electrolyte for solid-state batteries and the introduction of Li vacancies can be an efficient approach to greatly improve the ionic conductivity of other electrolytes. [ABSTRACT FROM AUTHOR]

Current industrial use of methane depends mainly on high-temperature conversion, resulting in high energy consumption and catalyst sintering inactivation. In this paper, metal oxide catalysts with different Ni/Cr ratios were obtained by the sol-gel method for the methane activation reaction. The structure-property relationships of the catalysts were investigated by XRD, XPS, H 2 -TPR, TG, N 2 adsorption-desorption, and CV, focusing on the interaction between Ni–Cr in the composite oxide catalysts. The results showed that Ni0–NiCrO 3 /Cr 2 O 3 structure was formed after the Ni–Cr oxides underwent the reduction and calcination process, which provided a structural support for electron transfer between the two metals. The least prone to sintering nickel metal particles and the highest content of high-valent chromium ions were present in Ni 1 Cr 2. XPS confirmed that this counterpart acts as the donor and acceptor for electron transfer in the catalysts, accelerating oxidation-reduction reaction over the catalyst. The catalyst exhibited the most excellent conversion and product selectivity in the methane activation reaction. • The Ni0–NiCrO 3 /Cr 2 O 3 structured catalysts were synthesized. • Ni0 electron rich, easily gives electrons, activation of methane with NiCrO 3. • Highly valent Cr ions are electronegative, attracting electrons from Ni0. • The electron transfer between Ni and Cr accelerated the redox reaction. [ABSTRACT FROM AUTHOR]

Controllably regulating the electrostatic bilayer of nanogold colloids is a significant premise for synthesizing spherical nucleic acid (SNA) and building ordered plasmonic architectures. We develop a facile acoustic levitation reactor to universally synthesize SNAs with an ultra‐high density of DNA strands, which is even higher than those of various state‐of‐the‐art methods. Results reveal a new mechanism of DNA grafting via acoustic wave that can reconfigure the ligands on colloidal surfaces. The acoustic levitation reactor enables substrate‐free three‐dimentional (3D) spatial assembly of SNAs with controllable interparticle nanogaps through regulating DNA lengths. This kind of architecture may overcome the plasmonic enhancement limits by blocking electron tunneling and breaking electrostatic shielding in dried aggregations. Finite element simulations support the architecture with 3D spatial plasmonic hotspot matrix, and its ultrahigh surface‐enhanced Raman scattering (SERS) capability is evidenced by in situ untargeted tracking of biomolecular events during photothermal stimulation (PTS)‐induced cell death process. For biomarker diagnosis, the conjugation of adenosine triphosphate (ATP) aptamer onto SNAs enables in situ targeted tracking of ATP during PTS‐induced cell death process. Particularly, the CD71 receptor and integrin α3β1 protein on PL45 cell membrance could be well distinguished by label‐free SERS fingerprints when using specific XQ‐2d and DML‐7 aptamers, respectively, to synthesize SNA architectures. Our current acoustic levitation reactor offers a new method for synthesizing SNAs and enables both targeted and untargeted SERS analysis for tracking molecular events in living systems. It promises great potentials in biochemical synthesis and sensing in future. [ABSTRACT FROM AUTHOR]

The medicinal halophyte plant Apocynum venetum L. can tolerate high salt levels in the soil, which significantly affects its growth and development. To study the molecular mechanisms underlying its environmental adaptations, omics tools were employed. Apocynum venetum L. plants were subjected to varying levels of salt stress. The corresponding RNA of Apocyni Veneti Folium (AVF), the leaf of Apocynum venetum L., was sequenced using a de novo approach. Functional annotation and expression analysis were utilised to identify differentially expressed transcription factors (TFs). The classification of these TFs was further divided into different families, including AP2/ERF, bHLH, WRKY, and HSF. Under conditions of modest saline stress, the majority of TF genes exhibited a predilection for up-regulation, particularly bHLHs, which were discovered to be consistent with the build-up of flavonoid glycosides. In conjunction with previous proteomics and metabolomics findings, we have discovered that the gene bHLH35 is a potential candidate. This gene has shown changes at both the transcript and protein levels, indicating that it may play a crucial role in the biosynthesis of flavonoids under salt-induced environments. These findings provide invaluable information on the identification of key genes involved in elucidating flavonoid biosynthesis mechanisms and serve as a basis for the improvement of the halophyte AVF's quality. [ABSTRACT FROM AUTHOR]