Search Results (12,402)

Indoor air temperature influences heat exchange between sleeping infants and indoor environments, yet its effects on convective and radiative dry heat transfer in ordinary ventilated rooms remain unclear. Using a previously validated three-dimensional CFD model of a realistic 9-month-old nude infant thermal manikin, this study simulated body-surface heat transfer at 18, 21, 23, 25, and 28 °C. A low-Re k-epsilon turbulence model was coupled with a surface-to-surface radiation model to calculate convective and radiative heat fluxes and heat transfer coefficients. Results showed that chamber airflow displaced the infant thermal plume toward the feet, exposing the head to cooler air and creating warmer microclimates around the lower limbs. At 18 °C, whole-body convective and radiative heat fluxes were 76.65 and 68.16 W/m², respectively; each 1 °C temperature increase reduced them by 5.24 and 3.74 W/m². Convection dominated at ≤21 °C, while radiation became dominant above 23 °C. The head showed the greatest temperature sensitivity, with convective and radiative heat fluxes decreasing by 61.08 and 41.66 W/m² from 18 to 28 °C. Empirical equations based on skin-to-environment temperature differences fitted most heat transfer coefficients well (R² > 0.93), providing boundary condition data for infant thermoregulation modeling and room thermal control. Full article

The economically important species Phyllanthus emblica L. has received increasing attention, yet its climate-driven distributional shifts across China remain unexplored. Using 446 occurrence records and a parameter-optimized MaxEnt model (RM = 0.1, FC = LQ), we forecasted habitat changes under three SSP scenarios (126, 370, 585) across the 2050s, 2070s, and 2090s. Three temperature variables, namely temperature seasonality (Bio4), temperature annual range (Bio7), and mean temperature of the driest quarter (Bio9), collectively contributed 90.2% to the model, confirming that thermal conditions, particularly during dry seasons, dominate habitat suitability. Current suitable habitat covers 86.43 × 10⁴ km², largely confined to South China’s tropical and southern subtropical belts. Future projections indicate non-linear range responses, with a general northwestward centroid shift, although intermediate periods exhibit oscillatory northeastward and southwestward fluctuations. Under the high-emission SSP585 scenario, modest expansion occurs in high-elevation areas of southeastern Tibet, while contraction affects less than 1% of current suitable low-elevation zones. Based on these findings, we recommend designating long-term core conservation areas (southern Yunnan, southern Guangxi, and Hainan), conducting adaptive introduction trials in expansion zones (e.g., Panzhihua, Sichuan), and implementing planting controls in contraction zones (e.g., northern Guizhou). These insights provide a scientific basis for climate-adaptive management of P. emblica in China. Full article

Accurate estimation of SOC for lithium-ion batteries is a very important job in battery management systems, but under complex dynamic operating conditions, model misalignment often happens, and filtering algorithms usually do not make enough use of historical data, so the estimation accuracy is lowered. This paper puts forward a lithium-ion battery SOC estimation method that is based on weighted multi-innovation unscented Kalman filtering (WMIUKF); a hybrid parameter identification strategy that combines FFRLS and PSO is introduced to supply initial values for the global optimization of the model and to track dynamic drifts. To deal with the problems that the unscented Kalman Filter (UKF) does not make effective use of historical information and lacks an adaptive correction mechanism, multi-innovation theory and exponentially decaying weighting factors are incorporated into it; then, by fusing current and historical multi-step prediction residuals, a weighted freshness matrix can be constructed, and through this the method, we can improve the utilization efficiency of historical data and the system’s ability to resist interference. The performance of the proposed algorithm was validated through comparative experiments under various typical dynamic operating conditions, as well as at different temperatures (0 °C–45 °C) and discharge rates (0.5 C–2 C). The results indicate that the PSO-FFRLS hybrid parameter identification effectively improves model accuracy; compared to the UKF, MIUKF, and PSO-MIUKF algorithms, the WMIUKF achieved optimal SOC tracking under all types of dynamic operating conditions, with a root mean square error (RMSE) of no more than 0.58%. Even under extreme temperatures and high-rate discharge conditions, the error remained stable at a low level, demonstrating good environmental adaptability and robustness. Full article

Physical processing can modify the structural, textural, and dispersion characteristics of nanostructured oxide materials, thereby altering their functional state under suspension conditions. Here, poorly crystalline, sol–gel-derived porous MnO_x materials were used to establish how post-synthetic physical processing affects the relationship between nanoscale structure, accessible mesoporosity, powder-to-suspension transfer, and chromogenic response in 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation. Two compositionally distinct processing series were examined: an ultrasonic processing/recovery route for Sr- and Fe-containing MnO_x and vibratory milling followed by identical ultrasonic dispersion for Sr-free Fe-containing MnO_x. The recovered SrFeMn-US-S solid showed higher N₂-accessible surface area and pore volume, stronger hydration signatures, and a larger low-temperature H₂ temperature-programmed reduction (H₂-TPR) contribution than SrFeMn-S. In contrast, vibratory milling of FeMn-S preserved the bulk Fe/Mn ratio but decreased S_BET from 305.9 to 127.1 m² g⁻¹, V_tot from 0.533 to 0.215 cm³ g⁻¹, total H₂ uptake from 0.38 to 0.34 mmol g⁻¹, and the Mn concentration in the operationally defined stable suspension fraction from 50.5 to 17.3 mg L⁻¹. At an identical assay concentration of 500 ng Mn mL⁻¹, milled FeMn-S5 also exhibited a lower time-summed ΣA₆₅₂ response than FeMn-S. Thus, milling affected both the efficiency of powder-to-suspension transfer and the Mn-normalized functional response of the dispersed material. The contrasting outcomes show that the functional state of nanostructured, powder-derived MnO_x is route-dependent and cannot be predicted from a single solid-state descriptor. Full article

Blueberry juice is valued for its distinctive flavor and health-promoting bioactive compounds, but thermal processing and subsequent storage can alter its quality and aroma. While previous studies have focused on total volatile profiles, the behavior of chiral aroma compounds—particularly linalool enantiomers—during processing and storage remains poorly understood. This study aimed to investigate the effects of pasteurization (PT, 90 °C for 30 s) and ultra-high temperature processing (UHT, 135 °C for 6 s) on the physicochemical properties, bioactive compounds, antioxidant activity, volatile profiles, and sensory characteristics of blueberry juice during storage at 4, 25, and 35 °C for 4 weeks, with a special emphasis on the enantiomeric changes in linalool. A chiral column-based GC-MS method was established to quantify (R)- and (S)-linalool enantiomers, given their distinct odor thresholds and sensory contributions. The results showed that both thermal treatments ensured microbial safety, but UHT caused greater color deterioration, loss of phenolics and anthocyanins, and formation of off-flavor compounds. PT better preserved color, bioactive components, and natural fruity aroma. Storage temperature was the dominant factor driving quality decline, with 4 °C significantly retarding deterioration. Notably, the two thermal processes exhibited distinct mechanisms affecting chiral linalool stability: PT primarily induced isomerization of (R)-linalool to the (S)-form, leading to a gradual decrease in the R/S ratio, whereas UHT led to direct degradation of (R)-linalool, resulting in a more rapid shift in the R/S ratio under the same conditions. These findings highlight the importance of monitoring enantiomeric composition rather than total linalool content for flavor quality assessment. The combination of PT and refrigerated storage (4 °C) is recommended to maximize overall quality retention, as PT better preserves the natural chiral balance of linalool. This study demonstrates that appropriate thermal processing and low-temperature storage are effective strategies to maintain the quality and chiral flavor stability of blueberry juice, providing new insights into the role of enantiomer-specific changes in processed fruit products. Full article

In pond-based shrimp culture, seawater exchange may introduce white spot syndrome virus (WSSV) from coastal waters, but infection risk at a given seawater viral concentration may vary with temperature, stocking density, and exposure duration. This study evaluated waterborne WSSV susceptibility in whiteleg shrimp (Penaeus vannamei) under these conditions. Shrimp were reared at 25 or 30 °C and at low (70), medium (140), or high (210 shrimp/m²) stocking densities; physiological responses were assessed, followed by short-term and continuous immersion challenges and a cohabitation challenge. Higher stocking-density conditions were associated with stress-related physiological changes and greater WSSV susceptibility. Under short-term exposure, 10⁷ WSSV genome copies/L caused infection only in the high-density group at 25 °C. Under continuous exposure, the minimum infective dose (MID) values were 10⁵ and 10⁴ WSSV genome copies/L at low and high stocking densities at 25 °C, and 10⁶ and 10⁵ WSSV genome copies/L, respectively, at 30 °C. Cohabitation transmission occurred at seawater viral loads below those associated with short-term immersion infection. By linking seawater viral concentrations with experimentally defined MID values and cohabitation-transmission outcomes, these results indicate that waterborne WSSV transmission risk should be assessed in relation to viral concentration, exposure duration, water temperature, and stocking-density conditions. Full article

Species-specific hematological reference intervals and reliable blood biomarkers are essential for physiological health assessment and disease diagnosis in aquaculture, yet such information remains unavailable for cultured starry flounder (Platichthys stellatus). This study aimed to establish hematological and plasma biochemical reference intervals for cultured starry flounder under optimal culture conditions and to identify diagnostic biomarkers associated with high-temperature stress. A total of 124 clinically healthy sub-adult starry flounder (mean total length, 28.9 ± 0.3 cm; mean body weight, 402.2 ± 13.7 g) were investigated under low—(4.1–5.7 °C, n = 30), optimal—(16–19 °C, n = 62), and high-temperature (26–28 °C, n = 32) conditions. Thirteen hematological and plasma biochemical variables, including osmolality, calcium, magnesium, cortisol, heat shock protein 70 (HSP70), glucose, total cholesterol, total protein, immunoglobulin M (IgM), aspartate aminotransferase (AST), alkaline phosphatase (ALP), hemoglobin, and hematocrit, were analyzed. Reference intervals were established for fish maintained under optimal temperature following ASVCP recommendations. Significant differences were observed among temperature groups in most blood variables (p < 0.05). Plasma cortisol exhibited the highest diagnostic performance for discriminating high-temperature fish (AUC = 0.870), followed by osmolality (AUC = 0.812). Principal component analysis demonstrated distinct physiological responses among temperature groups, while Random Forest analysis identified cortisol and osmolality as the most influential variables, with ALP, total protein, and AST also contributing to discrimination between optimal- and high-temperature fish. HSP70 concentrations tended to increase under high-temperature conditions, although the difference among temperature groups was not statistically significant. These findings provide the first hematological reference intervals for cultured starry flounder and identify plasma cortisol as the biomarker with the highest diagnostic performance for detecting high-temperature stress under the conditions examined. The proposed reference intervals and diagnostic biomarkers provide a practical framework for physiological health assessment and early thermal stress monitoring in starry flounder aquaculture. Full article

Temperature stress is a major constraint on the productivity of microalgae used in aquaculture. γ-Aminobutyric acid (GABA) is well-established as a key player in the stress tolerance of higher plants, yet its role in microalgae remains largely unexplored. Here, we examined the effects of low (15 °C), optimal (25 °C), and high (35 °C) temperatures on the GABA shunt in Isochrysis zhanjiangensis during the initial and mid-exponential growth phases. The results demonstrated that temperature stress significantly inhibited cell growth and photosynthetic efficiency (assessed by Fv/Fm and Fv’/Fm’), with soluble protein decreasing and soluble sugar accumulating. During the initial exponential phase, both low and high temperature stress triggered marked GABA accumulation, accompanied by coordinated increases in glutamate decarboxylase (GAD) and diamine oxidase (DAO) activities. Interestingly, the transcript levels of IzGAD and IzDAO decreased under these conditions, suggesting that GABA accumulation at this stage is predominantly governed by post-translational activation rather than transcriptional upregulation. Upon entry into the mid-exponential phase, a distinct phase-dependent shift in GABA biosynthetic regulation emerged. Under low temperature stress, GAD activity and IzGAD expression were both suppressed, whereas DAO activity and IzDAO transcripts increased significantly, indicating the transition to DAO-mediated GABA production as the dominant route. Under high temperature stress, both GAD and DAO activities increased, yet their corresponding gene transcription remained repressed, revealing a persistent asynchrony between enzyme activities and gene expression across both phases. Meanwhile, the expression of catabolic genes (IzGABA-T, IzSSADH1, and IzSSADH2) was consistently downregulated, further facilitating the net accumulation of GABA. Promoter analysis revealed multiple stress- and hormone-responsive cis-elements in these genes, implying a complex regulatory network. Collectively, our findings uncover a growth-phase-dependent reconfiguration of GABA biosynthetic pathways in I. zhanjiangensis under temperature stress. These insights provide a mechanistic basis for strain-specific temperature management in aquaculture applications. Full article

Protective coverings are an effective means of preventing direct fire exposure and delaying the charring of cross-laminated timber (CLT). This study evaluated the effects of practical covering configurations on the fire behavior and charring characteristics of four Korean larch CLT wall assemblies through 120-min fire resistance tests. The specimens varied in fire-resistant gypsum board thickness, joint arrangement, fastening details, and insulation conditions. Fire-induced damage, internal temperatures, and post-fire charring characteristics were evaluated. Specimens with non-staggered gypsum board joints exhibited cracking and detachment of the protective covering, resulting in localized flame penetration, with a maximum measured localized charring depth of 80 mm in CW-WS-G-1 and a measured localized charring depth of 73 mm in CW-WS-G-2. In contrast, specimens with staggered joints and improved fastening details largely maintained covering integrity. Only minor surface charring was observed in CW-WS-G-3, while no distinct charring occurred in CW-WS-W-1. The highest temperature recorded by the installed thermocouples was 225.2 °C in CW-WS-G-1, whereas the highest recorded temperatures in all other specimens remained below 100 °C. Nevertheless, localized charring occurred in CW-WS-G-2 despite its low internal temperature, indicating that temperature measurements alone may not adequately capture localized fire damage. These results indicate that, within the tested configurations, covering integrity associated with the combined joint arrangement and fastening details played an important role in limiting localized flame penetration and charring. Full article

Although traditional machine learning models demonstrate high accuracy in agricultural prediction scenarios, their “black box” nature prevents them from transparently presenting decision-making mechanisms and limits their reliability in integrated pest management (IPM) processes. In this study, the Cherry Fruit Fly (Rhagoletis cerasi) was investigated. A rule-based, explainable artificial intelligence (XAI) framework is proposed for characterizing bio-edaphic profiles associated with observed Cherry Fruit Fly Pupal Count (CfPC) density levels and classifying microclimatic aspects (Aspects) using measurable edaphic and biological parameters. The developed hierarchical rule inference engine parses the decision trees of the LightGBM classifier, which achieved the highest performance when benchmarked against 10 baseline machine learning algorithms (11 models in total), and extracts human-interpretable results that can be directly interpreted by experts. In Experiment 1, the analysis characterized the combinations of observed CfPC and edaphic conditions associated with Low, Medium, and High pupal-density profiles, whereas Experiment 2 evaluated the classification of canopy aspect from the measured bio-edaphic variables. According to the derived rules, continuous biological counts (CfPC) serve as the primary biological reference, while edaphic parameters such as soil temperature, pH, lime content, and water saturation percentage characterize additional soil conditions associated with the observed pupal-density profiles. These synthesized rules provide an interpretable representation of the bio-edaphic patterns observed within the studied orchards and may support the development of future precision crop-protection strategies following independent validation. Full article

With the continuous decline in easily recoverable reserves of conventional oil and gas, the focus of oil and gas exploration and development has gradually shifted toward complex reservoirs, such as low-permeability, tight, high-temperature and high-pressure (HTHP), and strongly heterogeneous reservoirs. Such reservoirs are characterized by complex pore–throat structures, poor seepage capacity, extreme temperature and pressure conditions, and strong heterogeneity. Traditional acidizing technologies face multiple challenges, including short effective penetration distances, system instability at high temperatures, uneven stimulation, and a tendency to induce secondary formation damage, making it difficult to meet the requirements for highly efficient reservoir stimulation. This paper systematically analyzes the petrophysical properties and acidizing challenges of four typical types of complex reservoirs. It reviews the reaction mechanisms, research and development progress, and reservoir adaptability principles of six acid systems, and elaborates on the application value of molecular simulation technology in acid–rock reaction analysis, formulation optimization, and injection regulation. The review indicates that, under extreme operating conditions, existing technologies still suffer from inadequate system stability, limited deep mass transfer, and environmental concerns. Future research should deepen the understanding of multi-scale acid–rock reaction mechanisms, develop composite acid systems tolerant to extreme conditions, and drive the development of acidizing technologies toward refinement and intelligentization. Full article

The increasing depth of oil wells and associated elevated formation temperatures pose significant challenges to conventional crosslinked polymer gels used in hydraulic fracturing, as viscosity degradation severely impairs proppant transport and stimulation efficiency. In this study, a thermally stable organic boron crosslinker was developed and evaluated in combination with hydroxypropyl guar gum (HPG). The rheological performance of the crosslinked gel system was systematically investigated under high-temperature shearing conditions. At a guar gum concentration of 0.5 wt% and a crosslinker-to-gum ratio of 100:0.5, the system maintains a viscosity of 500 mPa·s at 120 °C and 170 s⁻¹, and the viscosity remains above 300 mPa·s after 60 min of continuous shearing, demonstrating outstanding thermal resistance. (For 0.3 wt% HPG, the optimal crosslinking ratio is 100:0.3; for 0.5 wt% HPG, the optimal ratio is 100:0.5). This gel formulation achieves efficient proppant transport with minimal additives. It maintains static proppant suspension for up to 48 h. After breaking, the fluid viscosity drops to approximately 5 mPa·s. With the addition of a flowback aid, surface tension can be reduced to as low as 16.29 mN/m, while the formation matrix permeability damage rate is limited to only 20.76%. Additionally, the gel features rapid breaking and low residue generation, making it highly suitable for high-temperature fracturing operations. Full article

When a thermal power unit operates under deep peak shaving and variable load conditions, the heat-resistant materials of the boiler’s heat exchange surfaces will suffer accelerated fatigue damage due to frequent thermal shocks. To grasp the evolution law of thermal shock damage in high-temperature heat-resistant steel for the key equipment of thermal power units, based on the 12Cr1MoVG heat-resistant steel, a plastic strain simulation analysis was conducted. Through numerical simulation, the coupling relationship among thermal shock duration, thermal stress evolution, equivalent plastic strain (PEEQ) accumulation, damage penetration depth, and fatigue life was investigated. The results show that extending the duration of thermal shock will increase the thermal stress of the material, causing the failure depth to increase from 2.24 mm to 2.6 mm, and the accumulation rate of PEEQ at different depths of the material to accelerate, with the theoretical life decreasing from 1.82 × 10⁵ cycles to 1.72 × 10⁵ cycles. Extending the duration of low-temperature exposure will reduce the thermal stress of the material, causing the failure depth to decrease from 2.24 mm to 2.03 mm, and the accumulation rate of PEEQ at different depths of the material to slow down, with the theoretical life increasing from 1.81 × 10⁵ cycles to 1.94 × 10⁵ cycles. The research results can provide reference for fatigue damage and life assessment of the high-temperature and high-pressure materials used in key equipment of thermal power. Full article

The sustainable management of olive pomace (OP) residues remains a major environmental challenge, requiring integrated strategies that enhance resource recovery while minimizing environmental impacts. This study evaluated the effects of OP-derived biochar (BC) produced at two pyrolysis temperatures (300 and 600 °C) and applied at two rates (5 and 10%, w/w) on composting performance and the physicochemical, biological, and nutrient characteristics of OP compost. Composting was initiated in a pilot-scale forced-aeration bioreactor to accelerate the decomposition of the composting mixture, after which the materials were transferred to indoor piles to complete the composting and maturation process. Two-way ANOVA showed that both BC pyrolysis temperature and application rate significantly affected several compost quality attributes, although their relative influence varied among the measured properties. The observed responses were consistent with differences in the physicochemical characteristics of the OP-derived BC resulting from the pyrolysis conditions. Compared with BC produced at 300 °C, BC produced at 600 °C significantly reduced moisture content (MC) from 17.81 to 11.44%, decreased bulk density (BD) from 0.69 to 0.52 g cm⁻³, increased organic matter (OM) from 70.61 to 82.78%, and raised compost pH from 7.67 to 8.43 (p < 0.001), and reduced microbial respiration from 2.00 to 1.60 CO₂ g⁻¹ OM day⁻¹ (p = 0.0270). Increasing the BC application rate from 5 to 10% significantly enhanced nitrogen (N) (1.64–1.79%), phosphorus (P) (0.57–0.67%), ammonium (NH₄⁺) (162–214 mg kg⁻¹), nitrate (NO₃⁻) (42.98–52.42 mg kg⁻¹), sulfur (S) (0.35–0.39%), and compost stability index (SI). Overall, the higher BC application rate, particularly when combined with BC produced at 600 °C, generally resulted in the most favourable compost characteristics, although several responses were statistically comparable with those obtained using BC produced at 300 °C and applied at 10%. Germination indices of 97.5–135.8% indicated that the final composts exhibited low phytotoxicity and generally mature. These findings indicate that integrating OP-derived BC into OP composting can improve the quality and stability of the resulting compost while providing an integrated strategy for the valorization of within circular bioeconomy approach. Full article

Rubber compounds intended for Mars exploration missions must remain elastic at extremely low temperatures while being manufactured in a reliable and energy-efficient manner. In this study, the effect of vulcanization temperature (100–160 °C) on the network structure and properties of butadiene/silicone rubber (BR/VMQ) blends was investigated, comparing a conventional sulfur curing system (REF) with the same system activated by fluoride anion obtained from tetra-n-butylammonium fluoride (TBAF). The fluoride anion acts as an in situ activator of elemental sulfur, through the opening of the S₈ ring, facilitating the crosslinking process at significantly lower temperatures. Fluoride enabled rapid vulcanization at 100–120 °C, shortening the optimum cure time from 129.1 min to 61.4 min at 100 °C and from 36.7 min to 16.9 min at 120 °C. Equilibrium swelling and thiol-amine analysis revealed opposite structural responses to lowered curing temperature: the crosslink density of the reference compounds increased (from 1.25 × 10⁻⁴ to 1.56 × 10⁻⁴ mol/cm³ between 160 °C and 120 °C), whereas that of the TBAF-containing compounds decreased (from 1.32 × 10⁻⁴ to 0.60 × 10⁻⁴ mol/cm³ between 160 °C and 100 °C), yielding networks dominated by elastic polysulfidic crosslinks (up to 97.2%). We attribute this to a suppressed crosslink maturation under conditions of reduced thermal energy and shortened curing time. Low-temperature curing also suppressed the crystallization of the VMQ phase (melting enthalpy decreasing from 1.23 J/g to 0.21 J/g for TBAF compounds), which we hypothesize results from insufficient energy for phase separation and regular chain packing in this strongly immiscible blend. TBAF-cured compounds exhibited lower tanδ peaks, a stable tanδ plateau between approximately −60 °C and +20 °C, a tanδ-peak shift towards lower temperatures with decreasing curing temperature, and higher elongation at break and tensile strength at −40 °C. The results show that low-temperature, fluoride-activated vulcanization is a promising route for tailoring BR/VMQ networks towards stable dynamic performance across the Martian daily temperature range. Full article