Search Results (3,988)

As a critically important global food crop, wheat has been increasingly threatened by the frequent occurrence of extreme high-temperature events, which impairs its growth and development, resulting in reduced seed-setting rate, compromised grain quality and diminished yield. Therefore, identifying heat-tolerant genes and enhancing thermotolerance through molecular breeding are essential strategies for wheat improvement. In this study, we retrieved spatial transcriptomic data from the public database PRJNA427246, which captured gene expression profiles in flag leaves and grains of the heat-sensitive wheat cultivar Chinese Spring (CS) under 37 °C heat stress at time points of 0 min, 5 min, 10 min, 30 min, 1 h, and 4 h. Weighted Gene Co-expression Network Analysis (WGCNA) was used to construct co-expression networks for flag leaf and grain transcriptomes. One highly significant module was identified in each tissue, along with 35 hub genes that showed a strong temporal association with heat stress progression. Notably, both modules contained the previously characterized thermotolerance gene TaMBF1c, suggesting that additional heat-responsive genes may be present within these modules. Simultaneous analysis of the expression data from four groups (encompassing different tissues and high-temperature treatments) for the 35 core genes revealed that genes from the TaHSP20 family, TaMBF1c family, and other related genes exhibit coordinated expression patterns in terms of the temporal dynamics and tissue distribution of stress responses. Additionally, 27 genes of the small heat shock protein (HSP20) family are predicted to be involved in the endoplasmic reticulum-associated degradation (ERAD) pathway. They assist in clearing misfolded proteins induced by stress, thereby helping to maintain endoplasmic reticulum homeostasis and cellular functions under stress conditions. Finally, the expression levels of three core genes, TaHSP20-1, TaPCDP4, and TaMBF1c-D, were validated by qRT-PCR in two wheat cultivars with distinct thermotolerance: S116 (Zhehuamai 2008) and S128 (Yangmai 33). These findings provide new insights into the molecular mechanisms underlying heat tolerance in wheat and offer valuable genetic resources for breeding thermotolerant varieties. Full article

To address the susceptibility of traditional concrete to explosive spalling and the lack of in situ damage-monitoring methods at high temperatures, in this study, a novel self-sensing, high-temperature-resistant Engineered Cementitious Composite (ECC) was developed. The matrix contains eco-friendly glass sand reinforced with a hybrid system of polypropylene fibers (PPFs) and carbon fibers (CFs). The evolution of mechanical properties and the multimodal self-sensing characteristics of the ECC were systematically investigated following thermal treatment from 20 °C to 800 °C. The results indicate that the hybrid system exhibits a significant synergistic effect: through PFFs’ pore-forming mechanism, internal vapor pressure is effectively released to mitigate spalling, while CFs provide residual strength compensation. Mechanically, the compressive strength increased by 51.32% (0.9% CF + 1.0% PPF) at 400 °C compared to ambient temperature, attributed to high-temperature-activated secondary hydration. Regarding self-sensing, the composite containing 1.1% CF and 1.5% PPF displayed superior thermosensitivity during heating (resistivity reduction of 49.1%), indicating potential for early fire warnings. Notably, pressure sensitivity was enhanced after high-temperature exposure, with the 0.7% CF + 0.5% PPF group achieving a Fractional Change in Resistivity of 31.1% at 600 °C. Conversely, flexural sensitivity presented a “thermally induced attenuation effect” primarily attributed to high-temperature-induced interfacial weakening. This study confirms that the “pore-formation” mechanism, combined with the reconstruction of the conductive network, governs the material’s macroscopic properties, providing a theoretical basis for green, intelligent, and fire-safe infrastructure. Full article

2-acetylfuran is a product of the Maillard reaction and is widely found, especially in heat-processed foods such as grain products, baked goods, and dairy products. Although 2-acetylfuran contributes to flavor, high concentrations may be toxic. Its target organs and dose–response relationships remain poorly characterized. In this study, transgenic zebrafish with fluorescently labeled immune and neural systems were used to assess the effects of 2-acetylfuran on immune and neural development. Wild-type zebrafish were employed to assess the toxicity of 2-acetylfuran on locomotor ability, gastrointestinal development, and liver function. The maximum non-lethal concentration (MNLC) and the 10% lethal concentration (LC₁₀) for zebrafish embryos were 0.844 and 0.889 μL/mL, respectively. Regarding immunotoxicity, at concentrations of 0.281, 0.844, and 0.889 μL/mL, 2-acetylfuran significantly reduced the numbers of neutrophils, T cells, and macrophages. Regarding locomotor and neurotoxicity, motor speed and total locomotor distance were significantly reduced at 0.844 and 0.889 μL/mL. These findings were consistent with neurodevelopmental assessments, in which 0.844 μL/mL 2-acetylfuran resulted in a significant increase in apoptotic cells in the central nervous system and markedly shortened peripheral motor nerve lengths. Regarding gastrointestinal toxicity, 0.844 and 0.889 μL/mL 2-acetylfuran significantly reduced the gastrointestinal area, while neutrophil counts showed no significant changes, suggesting a relatively mild effect on the gastrointestinal tract. Regarding hepatic toxicity, all tested concentrations of 2-acetylfuran primarily increased the delayed yolk sac absorption area. Furthermore, at 0.844 μL/mL, histological examination revealed hepatic pathological changes characterized by hepatocyte nuclear swelling, vacuolar degeneration, and hepatocyte necrosis. In summary, this study reveals the multi-organ toxicity profile of 2-acetylfuran in the zebrafish model, with particularly high sensitivity in the immune system and liver. This research provides theoretical support for risk assessment and process control of 2-acetylfuran in foods. Full article

Rural self-constructed homes in China’s cold-temperate regions often exhibit poor energy performance due to limited budgets and substandard construction, leading to a high reliance on active systems and low climate resilience. This study assesses four passive cooling strategies, nighttime natural ventilation (NNV), envelope retrofitting (ER), window shading (WS), and window-to-wall ratio adjustment (WWR), under 2040–2080 representative future climate conditions using energy simulation, multi-objective optimization, sensitivity analysis, and life-cycle cost assessment. Combined measures (COM) cut annual cooling demand by ~43% and representative peak cooling loads by ~50%. NNV alone delivers ~37% cooling reduction with rapid payback, while ER primarily mitigates heating demand. WS provides moderate cooling but slightly increases winter energy use, and WWR has minimal impact. Economic and sensitivity analyses indicate that COM and NNV are robust and cost-effective, making them the most suitable strategies for low-energy, climate-resilient retrofits in cold-climate rural residences. Since statistically extreme heat events are not explicitly modeled, the findings reflect relative performance under representative climatic conditions rather than guaranteed resilience under extreme heatwaves. Full article

As a natural refrigerant, CO₂ shows significant potential in sustainable thermal engineering due to its environmental safety and economic viability. While the transcritical CO₂ cycle demonstrates strong performance in heating, low-temperature applications, and integration with renewable energy sources, its widespread adoption is hindered by key challenges at the application level. These include: high sensitivity of system efficiency to operating conditions, which creates an “efficiency hump” and narrows the optimal operating window; increased component costs and technical challenges for key devices such as multi-channel valves due to high-pressure requirements; and complex system control with limited intelligent solutions currently integrated. Despite these challenges, the transcritical CO₂ cycle holds unique value in enabling synergistic energy conversion. Its ability to efficiently match and cascade different energy grades makes it particularly suitable for data center cooling, industrial combined cooling and heating, and solar–thermal hybrid systems, positioning it as an indispensable technology in future low-carbon energy systems. To fully realize its potential, development efforts must focus on high-value applications and key technological breakthroughs. Priority should be given to demonstrating its use in fields where it holds a distinct advantage, such as low-temperature refrigeration and high-temperature industrial heat pumps, to establish commercially viable models. Concurrently, core technologies—including adaptive intelligent control algorithms, high-efficiency expanders, and cost-effective pressure-resistant components—must be advanced. Supportive policies, encompassing energy efficiency standards, safety regulations, and fiscal incentives, will be essential to facilitate the transition from demonstration projects to widespread industrial adoption. Full article

Trees are known to modify radiation on building façades via shading effects. However, the combined influence of tree morphological traits and street canyon geometry on façade solar exposure remains inadequately quantified. This paper will fill this gap by using an integrated field measurement, ENVI-met simulations and theoretical analysis of an east–west street canyon in Hangzhou, China. We present the stratified cumulative shortwave radiation disturbance (SRD) and the mean value (MSRD) of R as indices for assessing the influence of the tree height (TH), canopy diameter (D_C), leaf area density (LAD), and under-canopy height (UH) on the shortwave radiation profile of the south façade. Using 54 parametrized simulation scenarios, it was found that tree height is the most sensitive parameter to affect MSRD in the 1114 m range, with under-canopy height defining the building layers below. An LAD of 2 m²/m³ will be an optimal shading and daylighting. When discussed in terms of space, a canopy diameter of 5 m and a wall-to-canopy distance of 1 m (D_W-T) provides better shading in asymmetric canyons where the buildings in the south are lower. Further, canyon building height on either side of the canyon is found to be a decisive factor that mediates tree impacts on radiation, which allows specific approaches to greening canyons of diverse kinds. Through this work, there is a theoretical basis for understanding how trees and canyons interact, and this work gives scientific principles for a tree-planting initiative to reduce urban heat islands. Full article

This paper presents a closed-loop price–dispatch framework for park-scale virtual power plants (VPPs) with coupled electric–thermal processes under high penetrations of photovoltaics (PVs) and electric vehicles (EVs). The outer layer clears time-varying prices for operator electricity, operator heat, and user feed-in using an improved particle swarm optimizer with adaptive coefficients and velocity clamping. Given these prices, the inner layer executes a lightweight linear source decomposition with feasibility projection that enforces transformer limits, combined heat-and-power (CHP) and boiler constraints, ramping, energy balances, and EV state-of-charge requirements. PV uncertainty is represented by a small set of scenarios and a conditional value-at-risk (CVaR) term augments the welfare objective to control tail risk. On a typical winter day case, the coordinated setting aligns EV charging with solar hours, reduces evening grid imports, and improves a social welfare proxy while maintaining interpretable price signals. Measured outcomes include 99.17% PV utilization (95.14% self-consumption and 4.03% routed to EV charging) and a reduction in EV charging cost from CNY 304.18 to CNY 249.87 (−17.9%) compared with an all-from-operator benchmark; all transformer, CHP/boiler, and EV constraints are satisfied. The price loop converges within several dozen iterations without oscillation. Sensitivity studies show that increasing risk weight lowers CVaR with modest welfare trade-offs, while wider price bounds and higher EV availability raise welfare until physical limits bind. The results demonstrate an effective, interpretable, and reproducible pathway to integrate market signals with engineering constraints in park VPP operations. Full article

This paper presents a pressure-driven liquid transfer system for laboratory automation, along with a physics-based model and calibration method. The device maintains near-isothermal transport by storing reagents at a prescribed temperature and routing the flow through a single PTFE tube enclosed within a heated jacket. The pressure-drop model accounts for temperature-dependent viscosity and the thermal expansion of PTFE. Residual deviations from the no-slip prediction in submillimeter tubing are represented by an effective slip length, which is identified through linear regression. This parameter is subsequently used to calculate the pressure required to achieve a target flow rate. Experimental results compare unheated and heated operating conditions and characterize the dependence of slip length on temperature and flow rate. Under heated operation with slip-compensated pressure commands, the system achieved dispensing accuracy within $\pm 4\%$ over the tested range, whereas unheated operation exhibited larger errors due to axial temperature gradients. These results demonstrate that effective thermal management and slip compensation are critical for accurate pressure-based metering under temperature-sensitive conditions, as validated using water-based tests. Full article

Hydrogen-based energy systems require large amounts of high-purity water, motivating thermally driven desalination that can recover low-grade heat. This study evaluates a silica gel–water adsorption chiller–desalination unit as a coupled source of cooling and pre-treated water for electrolysers. A laboratory two-bed system was tested on saline feed using 300 s valve-switching periods at an 80 °C driving temperature and 20–30 °C cooling water. Dynamic vapour sorption measurements provided Dubinin–Astakhov equilibrium and linear driving force kinetic parameters, implemented in a CFD porous bed model via user-defined source terms. Experiments yielded COP values of 0.29–0.41, an SCP of 165 W·kg⁻¹ of adsorbent, and an average distillate production of 1.68–1.82 kg·h⁻¹, while distillate conductivity remained ≈2.3 μS·cm⁻¹. The model reproduced the mean condensate production with a ≈6% underprediction. It was then used to compare six alternative fin geometries with a constant heat-transfer area. Fin-shape modifications changed inter-fin heating by <2 K and cumulative desorbed mass by <0.05%, indicating limited sensitivity to subtle local refinements. Performance gains are more likely to arise from operating conditions and exchanger-scale architecture than from minor fin-shape changes. Full article

In this study, a three-dimensional Inverse Conjugate Heat Transfer Problem (ICHTP) is numerically and experimentally investigated to estimate the heat-source strength of multiple chips mounted on a printed circuit board (PCB) using the Conjugate Gradient Method (CGM) and infrared thermography. The interfaces between the PCB and the surrounding air domain are assumed to exhibit perfect thermal contact, establishing a fully coupled conjugate heat transfer framework for the inverse analysis. Unlike the conventional Inverse Heat Conduction Problem (IHCP), which typically only accounts for conduction within solid domains, the present ICHTP formulation requires the simultaneous solution of the governing continuity, momentum, and energy equations in the air domain, along with the heat conduction equation in the chips and PCB. This coupling introduces substantial computational complexity due to the nonlinear interaction between convective and conductive heat transfer mechanisms, as well as the sensitivity of the inverse solution to measurement uncertainties. The numerical simulations are conducted first with error-free measurement data and an inlet velocity of u_in = 4 m/s; the recovered heat-sources exhibit excellent agreement with the true values. The computed average errors for the estimated temperatures ERR1 and estimated heat sources ERR2 are as low as 0.0031% and 1.87%, respectively. The accuracy of the estimated heat sources is then experimentally validated under various prescribed inlet air velocities. During experimental verification at an inlet velocity of 4 m/s, the corresponding ERR1 and ERR2 values are obtained as 0.91% and 3.34%, while at 6 m/s, the values are 0.86% and 2.81%, respectively. Compared with the numerical results, the accuracy of the experimental estimations decreases noticeably. This discrepancy arises because the numerical simulations are free from measurement noise, whereas experimental data inherently include uncertainties due to thermal picture resolutions, environmental fluctuations, and other uncontrollable factors. These results highlight the inherent challenges associated with inverse problems and underscore the critical importance of obtaining precise and reliable temperature measurements to ensure accurate heat source estimation. Full article

In recent years, diagnostic technologies that utilize noninvasively collected sweat have garnered significant interest. However, the concentration of components in sweat is lower than that in blood, making the introduction of a concentration step as a sample pretreatment crucial for achieving highly sensitive detection. In this study, we developed a PDMS-based microchannel filled with silica gel, a desiccant particle, to concentrate liquid samples at room temperature without requiring an external power source or heating. The evaluation of the basic characteristics of the fabricated microchannel confirmed that filling it with silica gel efficiently removed the solvent vapor from the liquid samples. In concentration tests using the fluorescent dye uranine as a model for sweat sugar, a maximum 1.4-fold concentration was achieved in DPBS solution and a 1.2-fold concentration in artificial sweat at room temperature. In contrast, no similar concentration effect was observed in microchannels without silica gel packing. The proposed silica-gel-packed PDMS microchannel features a simple structure and requires no external equipment, making it easily integrable with existing microfluidic devices as a sample pretreatment module. This method is considered useful as a passive and simple sample concentration technique for the analysis of low-molecular-weight components in sweat. Full article

This study investigates the early-age performance of large-area C30 concrete slabs under different curing regimes using a multi-scale approach combining laboratory experiments, field monitoring, and numerical simulation. The experimental results indicated that standard curing (SC7) maximized the mechanical properties. In contrast, the thermal insulation and moisture retention curing (TC) regime significantly reduced temperature gradients and stress mutation amplitudes by 42% compared to wet curing (WC) by leveraging the synergistic effect of aluminum foil and insulating cotton. This makes TC a preferred solution in situations where engineering constraints apply. Field monitoring demonstrated that WC is suitable for humidity-sensitive scenarios with low-temperature control requirements, while TC is more suitable for large-area concrete or low-temperature environments, balancing early strength development and long-term durability. This multi-field coupled model exhibits significant deviations during the early stage (0–7 days) due to complex boundary interactions, but achieves high quantitative accuracy in the long-term steady state (after 14 days), with a maximum error below 8%. The analysis revealed that the key driving factors for stress evolution are early hydration heat–humidity coupling and mid-term boundary transient switching. The study provides a novel, multi-scale validated curing optimization path for crack control in large-area concrete slabs. Full article

Polyethylene is the most used plastic in the world, and over 90% of this plastic is ultimately disposed of in landfills or released into the environment, leading to severe ecological implications. In this research, the technoeconomic feasibility of upcycling low-density polyethylene (LDPE) to produce ethylene is studied. The catalytic conversion of LDPE to ethylene is considered in microwave heating mode and Joule heating mode. Experimental data is obtained under conditions where most of the upcycled products are in the gas phase. A flowsheet is developed that produces industrial quantities of ethylene for both heating modes. A technoeconomic analysis and a life cycle analysis are conducted and compared with the traditional ethane cracking process for producing ethylene. Simulation results indicate that the upcycling system exhibits a lower capital expenditure and a comparable operating expenditure relative to conventional ethane steam cracking while generating additional valuable co-products, such as propylene and aromatic hydrocarbons, leading to a higher net present value potential. Sensitivity analyses reveal that the electricity price has the most significant impact on both the net present value and levelized cost of production, followed by the low-density polyethylene feedstock cost. Life-cycle assessment reveals a substantial reduction in greenhouse-gas emissions in the upcycled process compared to the fossil-based ethane steam-cracking route, primarily due to the use of renewable electricity, the lower reaction temperature that reduces utility demand, and the use of plastic waste as the feedstock. Overall, the proposed process demonstrates strong potential for the sustainable production of ethylene from waste LDPE. Full article

Litchi (Litchi chinensis Sonn.) is a pillar of the tropical agricultural economy in southern China, yet its production faces increasing instability due to climate change. Traditional agronomic models often fail to capture the complex, non-linear interactions between meteorological drivers and yield formation in perennial fruit trees. To address this challenge, the study constructed a yield prediction framework using an optimized Random Forest (RF) model integrated with interpretable machine learning (SHAP), based on a comprehensive dataset from 17 major production regions in Hainan Province (2000–2022). The model demonstrated robust predictive capability at the provincial scale (R² = 0.564, RMSE = 2.1 t/ha) and high consistency across regions (R² ranging from 0.51 to 0.94). Feature importance analysis revealed that heat accumulation (specifically growing degree days above 20 °C) is the dominant driver, explaining over 85% of yield variability. Crucially, scenario simulations uncovered asymmetric climate risks across phenological stages: while moderate warming generally enhances yield by promoting vegetative growth and ripening, it acts as a stressor during the Fruit Development stage, where temperatures exceeding 26 °C trigger yield decline. Furthermore, the yield penalty for drought during Flowering (−8.09%) far outweighed the marginal benefits of surplus rainfall, identifying this window as critically sensitive to water deficits. These findings underscore the necessity of phenology-aligned adaptation strategies—specifically, securing irrigation during flowering and deploying cooling interventions during fruit development—providing a data-driven basis for climate-smart management in tropical agriculture. Full article

This study presents a gradient-based topology optimisation framework for heat sinks embedded with phase-change material (PCM) that targets the mitigation of temperature oscillations under cyclic thermal loads. The approach couples transient thermal diffusion modelling in FEniCS with automatic adjoint sensitivities and GCMMA, and uses a simple analytical homogenisation to parametrise a composite of PCM and conductive material. With latent-heat buffering using PCM, the optimised layouts reduce the temperature variance by 41% when the full time history is used and by 32% when only the quasi-steady-state cycle is used. To improve physical manufacturability, explicit penalisation yields near-discrete designs with only ∼10% performance loss, preserving most oscillation reduction benefits. The results demonstrate that adjoint-driven PCM topology optimisation can systematically suppress thermal oscillations. Full article