Temperature Stability Research Articles

Transforming sludge into energy: impact of blend percentage on energy recovery potential and environmental benefits of co-combustion of wastewater sludge and coal in Brazil.

Proper waste management and sustainable energy production are crucial for human development. For this purpose, this study evaluates the impact of blending percentage on energy recovery potential and environmental benefits of co-combustion of wastewater sludge and Brazilian low-rank coal. The sludge and coal were characterised in terms of their potential as fuel and co-combustion tests were carried out in a pilot-scale bubbling fluidised bed focused on the influence of the percentage of sludge mixture on the behaviour of co-combustion with coal in terms of flue gas composition and fluidised bed temperature stability. Sludge has a higher heating value (16.276MJ/kg) than coal (15.486MJ/kg) and a higher fuel ratio (8.48 vs. 0.21). The O2 and CO2 levels found in the co-combustion tests, together with a very low CO concentration, indicate good combustion. However, the NOx emission was considerable, varying from 825.2±94.5 to 1,320.5±33.8mg/m3 (O2ref=7%), pointing to the need for actions to reduce atmospheric pollution. Coal had higher ash content (52.64% vs. 25.00% d.b.). The temperatures in the bed region and in the combustion region showed similar behaviour for all the fuels. The addition of sewage sludge to mineral coal reduced the ash content without increasing the ash fusibility risk in the combustion temperature range evaluated. These findings suggest that sludge addition in co-combustion with coal offers promising results for both energy production and environmental sustainability.

Molybdenum disulfide nanosheets hybridized with lysine molecules for highly efficient near-infrared photothermal energy conversion

The paper reports a facile way for noncovalent functionalization of 1T-MoS2 with L-lysine (Lys) monolayers. The structure of the resultant hybrid compound was revealed by the powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, absorption spectroscopy and density functional theory (DFT) calculations study. A significant strength of the in-layer organic and organic-inorganic hydrogen bonding amounting to 24.6 and 29.9 kcal per mole of Lys, respectively, was found to hold the hydrated Lys molecules arranged in 2D chains and keep these chains tightly bound to the MoS2 sheets. The MoS2 hybridization with Lys significantly rises the upper temperature stability limit of 1T-MoS2 polymorph, which possesses the remarkable photothermal properties in near infra-red (NIR) region. The hybrid structure demonstrates excellent photothermal light-to-heat conversion efficiency reaching 49.5% upon 808 nm laser irradiation and higher thermal durability than unmodified 1T-MoS2.

Identical Fe-N4 Sites with Different Reactivity: Elucidating the Effect of Support Curvature.

Detailed atomic-scale understanding is a crucial prerequisite for rational design of next-generation single-atom catalysts (SACs). However, the sub-ångström precision needed for systematic studies is challenging to achieve on common SACs. Here, we present a two-dimensional (2D) metal-organic system featuring Fe-N4 single-atom sites, where the metal-organic structure is modulated by 0.4 Å corrugation of an inert graphene/Ir(111) support. Using scanning tunneling microscopy and density functional theory, we show that the support corrugation significantly affects the reactivity of the system, as the sites above the support "valleys" bind TCNQ (tetracyanoquinodimethane) significantly stronger than the sites above the "hills". The experimental temperature stability of TCNQ varies by more than 60 °C, while computations indicate more than 0.3 eV variation of TCNQ adsorption energy across the Fe-N4 sites placed atop different regions of the corrugated graphene unit cell. The origin of this effect is steric hindrance, which plays a role whenever large molecules interact with neighboring single-atom catalyst sites or when multiple reactants coadsorb on such sites. Our work demonstrates that such effects can be quantitatively studied using model SAC systems supported on chemically inert and physically corrugated supports.

Optimization of Erbium-Doped Fiber to Improve Temperature Stability and Efficiency of ASE Sources

The ASE (Amplified Spontaneous Emission) light source, based on erbium-doped fiber (EDF), is a broadband light source with advantages such as high power, excellent temperature stability, and low coherent light generation. It is widely used in the field of fiber optic sensing. However, traditional ASE sources suffer from temperature sensitivity and low efficiency, which can compromise the accuracy and stability of the output light’s average wavelength. This study focuses on optimizing the erbium-doped fiber (EDF) to improve the temperature stability and efficiency of the ASE light source. Through simulations, we found that the appropriate doping concentration and length of the EDF are key factors in enhancing the stability and efficiency of the ASE source. Inorganic metal chloride vapor-phase doping combined with an improved chemical vapor deposition process was used to fabricate the erbium-doped fiber, ensuring low background loss, minimal OH− absorption, and uniform distribution of the erbium ions in the core of the fiber. The optimized EDFs were integrated into the ASE source, achieving a power conversion efficiency of 53.6% and a temperature stability of 0.118 ppm/°C within the temperature range of −50 °C to 70 °C. This study offers a practical approach for improving the performance of ASE light sources and advancing the development of high-precision fiber optic sensing technologies.

ХАРАКТЕРИСТИКА ПРОЦЕССА ТЕПЛОВОЙ СТЕРИЛИЗАЦИИ ГЕТЕРОФАЗНОЙ ПИЩЕВОЙ СИСТЕМЫ НА ПРИМЕРЕ ЯБЛОЧНОГО СОКА С МЯКОТЬЮ

The paper presents the results of a study of the influence of thermostating regimes of a heterophase food system on cumulative lethality and rheological properties. Heterophase system FS – apple juice with pulp (RSV content – 11 %). The choice of FS is due to the maximum approximation of its properties to the properties of real FS from heterophase raw materials. To test the sterilization modes, FS was packed in glass jars with a capacity of 190 ml. The thermocouple was placed along the central axis of the jar at a geometric height of 18 mm. FS heating was carried out in a water thermostat of the WCH-16 type under isothermal conditions with a temperature stabilization error of no more than ±0.1 °C and subsequent cooling in water. Thermostat temperature range is 75, 80, 85, 90 and 95 °C. The processed experimental data of studies of heterophase FS are distinguished by a large variability in the nature of heating at the initial stage, which lasts about 10 minutes. The resulting character of the accumulation of lethality F(τ) for the entire temperature range tst 75–95 °C on the graphs is similar and differs in the obtained values. The average lethality of the F cycle was 10.3–223.72 minutes. High variability of heating dynamics FS from t0 to t ≈ tst largely depends on pomological varieties and the region where apples are grown, the ratio of puree and juice with pulp and processing equipment (crushers, mashers, homogenizers). The results of studies of the rheological properties of heterophase FS showed that within the heating range from 30 to 60 °C, it has the properties of a non-Newtonian fluid – a medium with a pronounced nonlinear change in dynamic viscosity with increasing shear rate

Microfluidic-Enabled Self-Directed Hydrogel Microspheres for Multiplexed MicroRNA Assays.

Multiplexed microRNA (miRNA) detection has proven valuable in disease diagnosis; yet, the development of advanced tools for their analysis remains a subject of broad interest. Here, we propose a novel single-particle method for multiplexed miRNA detection using self-directed hydrogel microspheres, which feature supersegmented compartments for loading analyte probes and an air-encapsulated region that grants the microsphere a unique preferred posture in aqueous solutions. By exploiting microfluidic technology, we can widely adjust the size of the microspheres and the number of compartments can be widely adjusted. The air-encapsulated region is located at the edge of the microsphere's symmetry axis, resulting in a spontaneous orientation that facilitates efficient multitarget signal readout in a standard manner without requiring active energy input. The microspheres exhibit excellent temperature stability, ensuring consistent performance under varying thermal conditions. Additionally, signal amplification strategies, such as hybridization chain reaction, are compatible with microspheres, enabling sensitive miRNA quantification. As a concept of proof, precise miRNA detection was demonstrated using these features. We hope that the proposed biocompatible microsphere tools will find broader application prospects in various clinical diagnostic settings.

Isolation, characterization and liposome-loaded encapsulation of a novel virulent Salmonella phage vB-SeS-01

IntroductionSalmonella is a common foodborne pathogenic bacterium, displaying facultative intracellular parasitic behavior, which can help the escape against antibiotics treatment. Bacteriophages have the potential to control both intracellular and facultative intracellular bacteria and can be developed as antibiotic alternatives.MethodsThis study isolated and characterized vB-SeS-01, a novel Guernseyvirinae phage preying on Salmonella enterica, whose genome is closely related to those of phages SHWT1 and vB-SenS-EnJE1. Furthermore, nine phage-carrying liposome formulations were developed by film hydration method and via liposome extruder.Results and DiscussionPhage vB-SeS-01 displays strong lysis ability against 9 out of 24 tested S. enterica strains (including the pathogenic “Sendai” and “Enteritidis” serovars), high replicability with a burst size of 111 ± 15 PFU/ cell and a titre up to 2.1 × 1011 PFU/mL, and broad pH (4.0 ~ 13.0) and temperature (4 ~ 80°C) stabilities. Among the nine vB-SeS-01 liposome-carrying formulations, the one encapsulated with PC:Chol:T80:SA = 9:1:2:0.5 without sonication displayed the optimal features. This formulation carried up to 1011 PFU/mL, with an encapsulation rate of 80%, an average size of 172.8 nm, and a polydispersity index (PDI) of 0.087. It remained stable at 4°C and 23°C for at least 21 days and at 37°C for 7 days. Both vB-SeS-01 and vB-SeS-01-loaded liposomes displayed intracellular antimicrobial effects and could reduce the transcription level of some tested intracellular inflammatory factors caused by the infected S. enterica sv. Sendai 16,226 and Enteritidis 50041CMCC.

Simulation Analysis of Temperature Field and Stress Field of Mass Concrete Under Different Construction Temperatures

In this study, the finite element analysis software MIDAS FEA NX was used to simulate and analyze the concrete, and the temperature regulation effect of phase change materials in concrete and its influence on crack resistance was discussed. A 1/8 concrete specimen model was constructed, and different ambient temperatures (5 °C to 35 °C) and concrete material parameters were set. Through simulation, it is found that phase change materials can effectively absorb environmental heat, maintain the temperature stability of concrete structures, and reduce the internal temperature peak. In addition, the addition of phase change materials can also reduce the temperature difference between the inside and outside of concrete, relieve the internal stress and improve the crack resistance of concrete. The results show that under different construction temperatures, the phase change concrete can quickly achieve the consistency of internal and external temperature and stress, reduce the cracking problem, and show good temperature regulation and crack resistance.

Erbium: key to simultaneously achieving superior temperature-stability and high magnetic properties in 2 : 17-type permanent magnets.

To address the demands of rapidly advancing precision instruments requiring higher efficiency and miniaturization, permanent magnets must exhibit exceptional energy density, temperature stability, high magnetic energy product [(BH)max], and adequate coercivity (Hcj). Herein, we design rare earth Er-based magnets (2 : 17-type Er-magnets) with a composition of (Er, Sm)(Co, Fe, Cu, Zr)7.6. Erbium-based compounds (Er2Co17) offer a unique combination of temperature compensation and high saturation magnetization compared to other heavy rare earth elements, resulting in 2 : 17-type Er-magnets with superior temperature stability in Br and (BH)max. Partially substituting Sm reduces the energy barrier for the 2 : 17H-to-2 : 17R phase transition, promoting the development of a complete cellular structure and achieving enhanced coercivity. Notably, the optimal performance is obtained with Er constituting 60% of the total rare earth content, delivering a near-zero temperature-coefficient for Br and (BH)max within 20-150 °C while maintaining Br at 8.92 kG, Hcj at 29.83 kOe, and (BH)max at 18.5 MGOe. These 2 : 17-type Er-magnets provide valuable insights for developing permanent magnets with exceptional comprehensive properties.

High-Temperature Polymer Composite Dielectrics: Energy Storage Performance, Large-Scale Preparation, and Device Design.

Film capacitors are widely used in advanced electrical and electronic systems. The temperature stability of polymer dielectrics plays a critical role in supporting their performance operation at elevated temperatures. For the last decade, the investigations for new polymer dielectrics with high energy storage performance at higher temperatures (>200 °C) have attracted much attention and numerous strategies have been employed. However, there is currently still a large gap between lab research and large-scale production. In this review, the main effects of high temperature on the dielectric properties are analyzed and core modification strategies are summarized. The scientific and technological reasons for the performance difference between lab research and practical application are also discussed. Further, several processes for large-scale film preparation and typical device structure design are reviewed. The current research and product launches pertaining of high-temperature film capacitors are also summarized. Conclusive insights and future perspectives are delineated to offer strategic direction for the ongoing and prospective innovation in polymer dielectric materials.

An Optimization Design of Energy Consumption for Aluminum Smelting Based on a Multi-Objective Artificial Vulture Algorithm

In the process of regenerative aluminum smelting, the temperature of the furnace needs to be maintained between 700 and 850 by adjusting the setting parameters of the smelting furnace. The setting parameters are usually adjusted by manual work, and inaccuracies in manual operation can lead to wasted energy as well as unstable temperatures. Energy consumption and temperature stability are two conflicting objectives, which are difficult to find optimal parameters for the aluminum smelting process. In this paper, an improved multi-objective artificial vulture algorithm (IMOAVOA) is developed to solve a multi-objective problem of energy consumption and temperature deviations in the regenerative aluminum smelting process. The dynamic switching–elimination mechanism based on crowding distance is proposed to maintain the archive, which enhances the diversity of solutions by dynamically switching the operation space for deleting redundant solutions in the archive and dynamically deleting the solution with the smallest crowding distance in the operation space. The multi-directional leader selection mechanism is developed to select better leaders. To improve the convergence of the algorithm, the bounce strategy is introduced in the IMOAVOA. The effectiveness of the proposed algorithm is verified by UF1-UF10, kursawe, Viennet2, Viennet3, ZDT1-ZDT6, DTLZ4, and DTLZ6 test functions with several multi-objective algorithms. The experimental results indicate that IMOAVOA outperforms the original algorithm and three other multi-objective algorithms in terms of the algorithm convergence, the Pareto front coverage, and the solution diversity. Finally, the proposed algorithm is tested in an application case of regenerative aluminum smelting process. The results show that the optimal parameters for the aluminum smelting process using the proposed algorithm can reduce the consumption while meeting the objective of furnace temperature.

Assessment of Fatigue Life and Failure Criteria in Ultrasonic Testing Through Thermal Analyses

An experimental study was conducted to analyze temperature evolution during very high cycle fatigue tests. The temperature–number of cycles (T–N) curve is typically divided into three phases: Phase I—a rapid temperature increases at the start of the test, Phase II—temperature stabilization, and Phase III—a sharp temperature rise at the test’s end, coinciding with specimen fracture. The high frequencies used in ultrasonic fatigue testing can induce self-heating in specimens, but the thermal effects are not yet fully understood. Temperature is known to influence the fatigue performance of materials. To explore this, specimens were subjected to varying stress levels and intermittent loading conditions while monitoring temperature evolution using infrared thermography. The T–N curves were obtained, and S–N curves were constructed for specimens tested at room temperature. All tests were performed under fully reversed loading conditions. The experimental data were used to evaluate models commonly applied in conventional fatigue testing. Additionally, the temperature gradient at the beginning of the ultrasonic fatigue test and the heat dissipation per cycle were estimated and analyzed as potential fatigue damage parameters. These findings indicate that parameters derived from the T–N curve have significant potential for predicting very high cycle fatigue life.

Ultra-flat electro-optic frequency comb based on a chirp-modulated lithium niobate resonator.

Chirp modulation can generate a relatively flat electro-optic frequency comb (EO comb) and offers the advantage of frequency reconfigurability, demonstrating significant potential in high-precision sensing and absorption spectroscopy measurements. However, nonresonant devices such as waveguides are susceptible to limitations in modulation efficiency and bandwidth during electro-optic modulation. In this paper, by utilizing chirp modulation resonance mode, we have realized an EO comb based on a lithium niobate resonator with small tooth spacing and high flatness. Theoretically, the chirp modulation of phase is achieved by modulating the dispersion coupling term in the resonant mode transmission equation. Compared with conventional waveguide-based EO combs, the resonant mode chirp modulation is capable of generating a multistage flat comb, and thus the bandwidth of the comb is significantly expanded. In the experiment, with a repetition rate as low as 20 kHz and a bias voltage of 1 V, the comb bandwidth extended to over 150 MHz, where the number of 3 dB flat comb teeth for a single stage exceeds 2,000. Finally, we evaluated the measurement capability of the frequency comb at different temperatures by utilizing the transmission spectrum of the germanium-doped silica waveguide cavity as the absorption spectrum, measuring a temperature sensitivity of 1505.00 MHz/K and a temperature instability of 1.13 mK/Hz1/2.

Experimental Studies of Enhancing Solar Collector Efficiency by using a Storage Tank Containing Water Pipes and PCM

Thermal energy storage is a crucial process for retaining heat for future use. This experimental study investigates the integration of a storage tank containing water pipes and phase change materials (PCM) with a solar collector system. By employing paraffin wax (RT-42) as the PCM and leveraging its latent heat storage properties, the enhancement of thermal efficiency and energy storage capabilities in the evacuated tube solar collector is evaluated. Experiments were conducted under varying solar radiation intensity and ambient temperatures in winter and summer conditions. A solar collector and heater were tested for efficiency during winter and summer. The collector was installed at 45.5°S and heated with 120 litres of water. The system's efficiency was enhanced with increased solar radiation and flow rates. The thermal charging of the system took place between 8:00 am and 4:00 pm. The results showed longer hot water supply times at 4 L/m. The effect of adding PCMs and water pipes to solar collector systems was investigated, revealing significant improvements in thermal performance and energy storage. The findings showed an enhancement in temperature stability, with peak temperatures reaching 60°C in winter and 75°C in summer at flow rates of 4, 6, and 8 L/m. Using a storage tank, hot water pipes and PCM, especially paraffin wax, with a latent heat of fusion of 174 kJ/kg improved energy retention and hot water supply. The experiment outcomes showed that the summer hot water supply was twice as high as the winter hot water supply. The study also highlights the importance of improving flow rates to absorb and retain heat efficiently. Overall, the combination of PCM and water pipes enhanced the system efficiency and increased the availability of thermal energy.

Study on the performance and mechanism of graphene oxide / polyurethane composite modified asphalt

In order to enhance the aging resistance, high temperature stability and low temperature crack resistance of asphalt pavement materials, 0.06% oxidized graphene (GO) and 12% polyurethane (PU) were used as composite modifiers to modify the base asphalt. The RTFOT test was conducted to evaluate the anti-aging performance of the modified asphalt. The rheological properties of GO/PU composite modified asphalt were evaluated. SEM and FTIR tests were used to analyze the microstructure of GO/PU modified asphalt. The results show that the basic performance of composite modified asphalt meets the requirements and the anti-aging performance is improved. The improvement of rutting factor and frequency scanning master curve shows its better anti-rutting deformation ability. The strain recovery R-value for the composite modified bitumen increased by 20.7% at a stress level of 0.1 kPa, and the unrecoverable creep compliance Jnr decreased by 76.0%, showing excellent viscoelastic properties. The creep stiffness S of composite modified asphalt decreased by 31.2% at−12 °C, indicating that it had good low temperature rheological properties. The surface of the modified composite asphalt is relatively smooth, exhibiting a stable network structure, thus solving the PU segregation problem in the matrix asphalt.The change of infrared spectrum absorption peak shows that reaction between isocyanate groups in polyurethane and aromatic esters in bitumen, GO oxidizes with the-CH functional group in asphalt, and the content of C = C double bond changes during the modification process, indicating that the modification of asphalt by GO and PU is a composite modification based on chemical modification and supplemented by physical modification.

Temperature stability of multilayer symmetric KNN-based ceramics with continuous phase transitions

Temperature stability of multilayer symmetric KNN-based ceramics with continuous phase transitions

Design and Application of Uniaxially Sensitive Stress Sensor.

Current stress sensors for microsystems face integration challenges and complex signal decoding. This paper proposes a real-time uniaxially sensitive stress sensor. It is obtained by simple combinations of bar resistors using their sensitivity differences in different axes. With the aid of a Wheatstone bridge, the sensor can measure the uniaxial stress magnitude by simple calibration of the stress against the output voltage and detect the bidirectional stress magnitude and direction in a micro-zone by simple rotation. The theoretical sensitivity obtained from simulation is 0.087 mV/V·MPa when the X-bridge is stressed in the X-direction under 1 V of excitation, and the test sensitivity of the X-bridge prepared in this paper is 0.1 mV/V·MPa. The design is structurally and procedurally simple, exhibits better temperature stability, and reduces interface requirements, making it suitable for the health monitoring of multi-chip microsystem chips.

Dual Actuator Control Strategy for Temperature Stability in High Temperature Solar Receivers

Abstract Fluctuations in incoming solar energy adversely affect the temperature stability within solar receivers, leading to a decrease in thermal efficiency. Therefore, it is essential to design a control system with the capability to maintain quasi-steady temperatures inside the reactor consistently throughout the day. This study introduces a dual actuator control technology to regulate the temperature within a high–temperature cylindrical cavity type gas receiver. The actuating system comprises two primary components. The first component involves a variable aperture mechanism, executed through a rotary mechanism made of stainless steel. This mechanism features seven holes of fixed diameters arranged in a half-circle configuration. The rotary mechanism is powered by a stepper motor regulated by a feedback control system. The second actuator is a Mass Flow Controller (MFC) responsible for meticulous adjustment of the inlet gas flow directed towards the solar receiver. The Direct Normal Irradiance (DNI) is simulated using a 10 kW High Flux Solar Simulator (HFSS) with a variable power supply ranging from 80 to 200 A. This setup enables the simulation of different operational conditions. The dual actuator method concurrently adjusts both gas flowrate and aperture size. While utilizing each of these methods individually can achieve reasonable temperature control performance, the hybrid approach leverages the strengths of both control methods, resulting in a significant improvement in the temperature regulation performance of the solar receiver. Two control strategies, namely Proportional Integral (PI) and Model Predictive Controller (MPC), were implemented to regulate the temperature inside a cavity type gas receiver. Experimental tests indicate that the incorporating the dual actuators controller is a promising technique, and its application can be extended to include additional parameters for utilization in a multi–input multi-output (MIMO) control system.

High-Rate 4.2 V Solid-State Potassium Batteries by In Situ Polymerized Epoxide Ether Electrolyte.

Solid-state metallic potassium batteries (SSMPBs) afresh have attracted incremental attention because of their potential to supplement solid-state metallic lithium batteries. However, SSMPBs suffer poor electrochemical performances due to the low ionic conductivity of solid electrolytes and huge electrode/electrolyte interfacial resistance. Herein, high-rate SSMPBs are achieved by in situ ring-opening polymerization of 1,3-dioxolane with succinonitrile as a plasticizer and Al(OTf)3 as the catalyst, where the succinonitrile enables short-chain polyether electrolytes. The in situ polymerized electrolytes deliver a high ionic conductivity of 4.5 × 10-5 S cm-1 at room temperature and excellent stabilities at high oxidation potentials (4.2 V vs K+/K) and against metallic K anodes. All these result in SSMPBs with a discharge capacity of 69 mAh g-1 under a high rate of 100 mA g-1 and a retention of 88.8% after 100 cycles, and the rate and capacity retention are higher than those in previous work on SSMPBs.

Heat Tolerance Differences Between Hu Sheep and Hu Crossbred Sheep in Microbial Community Structure and Metabolism.

The frequent occurrence of extreme temperature events causes significant economic losses to the livestock industry. Therefore, delving into the differences in the physiological and molecular mechanisms of heat stress across different sheep breeds is crucial for developing effective management and breeding strategies. This study explores the differences in heat tolerance mechanisms between Hu sheep and Xinggao sheep by comparing their growth performance under normal and heat stress conditions, as well as examining the differences in physiological, biochemical, and antioxidant indicators related to heat tolerance, serum metabolomics, and gut microbiomics in a heat stress environment. The results indicate that with changes in the temperature-humidity index (THI), Hu sheep exhibit superior stability in respiratory rate (RR) and rectal temperature (RT) fluctuations compared to Xinggao sheep. In terms of biochemical indicators and antioxidant capacity, the levels of creatinine (Cr) and superoxide dismutase (SOD) in Hu sheep serum are significantly higher than those in Xinggao sheep. In comparison, alkaline phosphatase (ALP) and malondialdehyde (MDA) levels are significantly lower. Metabolomic results showed that, compared to Hu sheep, Xinggao sheep exhibited higher cortisol (COR) and dopamine (DA) levels under heat stress conditions, a stronger lipid mobilization capacity, and elevated levels of tricarboxylic acid (TCA) cycle-related metabolites. Furthermore, gut microbiome analysis results indicate that Hu sheep demonstrate stronger cellulose degradation capabilities, as evidenced by significantly higher abundances of microorganisms such as Ruminococcus, Fibrobacter, and Bacteroidales_RF16_group, compared to Xinggao sheep. In summary, Hu sheep exhibit stronger heat tolerance compared to Xinggao sheep. These findings provide an important theoretical basis for the breeding and selection of heat-tolerant meat sheep varieties and offer strong support for the region's livestock industry in addressing the challenges posed by global warming.