Tuesday, July 14, 2026

 

Scientists uncover molecular mechanism linking water-saving irrigation to cadmium accumulation in rice



Chinese Academy of Sciences Headquarters
A proposed working model illustrating how ABA signaling links water status to Cd accumulation via theOsSAPK2-OsNAC4-OsNRAMP1 module in rice 

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A proposed working model illustrating how ABA signaling links water status to Cd accumulation via theOsSAPK2-OsNAC4-OsNRAMP1 module in rice

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Credit: SHEN Renfang's team





Water-saving irrigation practices, including intermittent irrigation, are essential for sustainable rice cultivation amid growing freshwater shortages. However, periodic drainage creates aerobic soil conditions that drastically boost cadmium (Cd) bioavailability, leading to severe grain Cd enrichment. Disentangling the relationship between water conservation and high grain Cd has been a critical challenge for rice breeders and soil scientists worldwide.

Now, a research team led by Profs. SHEN Renfang and ZHU Xiaofang from the Institute of Soil Science of the Chinese Academy of Sciences has identified a conserved molecular cascade that explains this phenomenon. Published online in Current Biology on July 8, the study demonstrates that drought and abscisic acid (ABA) signaling actively trigger excessive Cd uptake in rice under water-saving regimes.

Using CRISPR-Cas9 mutant screening, biochemical assays, and multi-location field trials, the researchers identified the transcription factor OsNAC4 as a key regulator of grain Cd accumulation. Phenotypic assays across multiple genetic backgrounds validated that the functional knockout of OsNAC4 reduces grain Cd concentrations by 30%–50% under intermittent irrigation, without any negative impacts on grain yield or key agronomic traits.

The researchers also identified the OsSAPK2–OsNAC4–OsNRAMP1 regulatory pathway as the mechanism by which OsNAC4 controls grain Cd accumulation. Under aerobic or drought conditions, activated endogenous ABA signaling stimulates the SnRK2-type kinase OsSAPK2, which then physically interacts with and phosphorylates OsNAC4 at four conserved serine residues. This process stabilizes OsNAC4 and enhances its DNA-binding affinity, thereby upregulating expression of OsNRAMP1. The OsNRAMP1 protein is a major plasma membrane transporter mediating root Cd uptake. This pathway is the molecular basis of the elevated levels of grain Cd that appear when rice plants face drought stress as part of water-saving irrigation practices.

Importantly, rice plants lacking OsNAC4 preserve the basal transport of essential metals like manganese and iron required for normal development even as stress-triggered excess Cd uptake is suppressed. In contrast, rice plants carrying direct mutations in genes encoding OsNRAMP family transporters often exhibit disrupted nutrient homeostasis and severe growth defects.

"Our work demonstrates that elevated grain Cd under drainage is not merely a passive consequence of soil redox shifts; rather, plants actively amplify Cd absorption via endogenous ABA signaling cascades in response to aerobic environments," said Prof. ZHU, one of the lead authors.

By characterizing the OsSAPK2–OsNAC4–OsNRAMP1 pathway, this study provides a precise theoretical framework to decouple water stress signaling from heavy metal accumulation, offering an effective breeding target to develop climate-resilient, low-Cd rice varieties compatible with water-limited agriculture.

Nanostructures offer new pathways to boost safety in aquaculture, review shows






Higher Education Press

Schematic for the sources, distributions, and migration routes of hazardous species in aquaculture products and matrices. 

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Schematic for the sources, distributions, and migration routes of hazardous species in aquaculture products and matrices.

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Credit: Qingsong Zhang, Xilong Wang et al.






A new review published in Engineering has summarized recent progress in using nanostructures to detect and eliminate hazards in aquaculture, providing technical support for safer aquatic products and more sustainable farming systems.

 

Aquatic products serve as a key protein and omega‑3 fatty acid source for global populations, yet rapid aquaculture expansion has brought persistent food safety risks, including marine toxins, heavy metals, microplastics and pathogenic bacteria. Conventional detection approaches often rely on bulky instruments, long assay times and complex operations, while traditional removal methods face limitations in efficiency, cost or secondary pollution. Benefiting from large surface areas and tunable physicochemical properties, nanostructures can be functionalized with antibodies, aptamers and ligands to act as sensing indicators, signal amplifiers, photocatalysts and separation materials.

 

The review covers applications across four major hazard categories. For marine toxins including saxitoxin, okadaic acid, brevetoxin and tetrodotoxin, nanostructure‑integrated sensors based on colorimetry, fluorescence, surface‑enhanced Raman scattering and electrochemistry have enabled rapid and sensitive detection. In heavy metal monitoring, nanomaterial platforms support colorimetric, SERS and smartphone‑assisted fluorescence detection, while magnetic and high‑surface‑area nanostructures provide effective adsorption toward mercury, lead, cadmium and copper ions in aquatic environments. For microplastics and nanoplastics, nanostructure‑assisted techniques including single‑particle ICP‑MS and SERS improve identification of tiny particles, and functional nanocomposites support adsorption and catalytic degradation. In terms of pathogenic bacteria such as Vibrio parahaemolyticus, Aeromonas hydrophila and Edwardsiella tarda, nanostructure‑based biosensors support rapid on‑site testing, and green nanostructured antimicrobials help control pathogens while reducing antibiotic reliance.

 

The review also discusses integration of nanostructures into existing aquaculture workflows and points to future directions, including improving stability in complex saline environments, enhancing detection sensitivity, developing multifunctional nanosystems, promoting sustainable and biodegradable nanomaterials, establishing standardized testing protocols and incorporating artificial intelligence in material design and data analysis. It also notes the need for corresponding standards and regulations to ensure environmental and food safety during large‑scale applications.

 

By offering sensitive, rapid and sustainable tools for hazard management, nanostructure technologies are expected to support the healthy development of aquaculture and contribute to global food security.

 

The paper “Enhancing Safety in Aquaculture with Nanostructures: Hazard Detection and Elimination,” is authored by Qingsong Zhang, Xilong Wang, Li Lian Wong, Shikai Liu, Ming Li, Guoqing Wang. Full text of the open access paper: https://doi.org/10.1016/j.eng.2025.07.044. For more information about Engineering, visit the website at https://www.sciencedirect.com/journal/engineering.

 

Probabilistic study assesses China’s energy-related carbon emission peak target





Higher Education Press

The research diagram for this study. 

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The research diagram for this study.

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Credit: Zheng Li, Chenpeng Li et al.






A new study published in Engineering provides a probabilistic evaluation of China’s ability to reach its energy-related carbon emission peak and related climate targets by 2030, accounting for uncertainties in total energy consumption and non-fossil energy development. Conducted by researchers from Tsinghua University, the analysis uses maximum likelihood estimation, Monte Carlo simulation, and random sampling to quantify the likelihood of goal achievement across different policy scenarios, without overstatement of outcomes.

 

The research notes that China has seen rapid growth in both primary energy consumption and renewable energy installed capacity, which jointly shape national carbon emission trends. Future pathways in these two areas carry substantial uncertainty, directly affecting the delivery of climate pledges including peaking carbon emissions before 2030, cutting CO₂ emissions per unit of GDP by more than 65% from 2005 levels by 2030, and raising the share of non-fossil fuels in primary energy consumption to around 25%. The study models uncertainties in economic growth, energy intensity reduction, and the deployment of wind, solar, nuclear, hydropower, and offshore wind power, treating solar and onshore wind as high-uncertainty variables while setting deterministic projections for other low-uncertainty non-fossil sources.

 

Under the baseline energy intensity scenario, China needs to either exceed 4000 GW of installed non-fossil energy capacity before 2030 or keep total energy consumption below 6500 million tons of coal equivalent (Mtce) to meet its climate commitments. The analysis covers four renewable energy policy scenarios, showing that stronger policy support for wind and solar raises the probability of peaking emissions on time, with diminishing marginal returns in probability gains beyond moderate ambition levels. The study also finds that achieving the GDP-linked carbon intensity target is more stringent than meeting the non-fossil energy share target, and that success in the former typically ensures fulfillment of the latter.

 

A slowdown in energy intensity reduction poses notable risks. If total energy consumption exceeds 8250 Mtce before 2030 due to weaker efficiency gains, it will become difficult for China to achieve all its climate goals within the studied uncertainty ranges. The framework calculates millions of sub-scenarios to map the combined effects of energy demand and non-fossil energy expansion, offering targeted policy suggestions including phased non-fossil capacity planning, region-specific technological innovation, and coordinated governance linking energy management and socioeconomic development to stabilize progress toward climate targets.

 

The findings offer a data-driven reference for balancing energy security, economic development, and decarbonization as China advances its dual-carbon objectives amid global energy transition challenges.

 

The paper “A Probabilistic Evaluation of China’s Energy-Related Carbon Emission Peak Target,” is authored by Zheng Li, Chenpeng Li, Yujuan Fang, Pei Liu, Ershun Du, Linwei Ma, Xiu Yang. Full text of the open access paper: https://doi.org/10.1016/j.eng.2025.07.018. For more information about Engineering, visit the website at https://www.sciencedirect.com/journal/engineering.

  

New coal purification-combustion method shows stable low-load performance and ultra-low NOâ‚“ emissions





Higher Education Press

Graphical abstract 

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Graphical abstract

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Credit: Shaobo Yang, Shaobo Han et al.






A research team from the Institute of Engineering Thermophysics, Chinese Academy of Sciences has reported a novel coal purification-combustion technology that enables stable and efficient ultra-low nitrogen oxide combustion under low-load conditions, as published in Engineering. The work was carried out on a 200 kW integrated test system, with a focus on purification performance and nitrogen migration mechanisms at approximately 55% load.

 

The technology integrates medium-temperature activation, high-temperature purification, and moderate or intense low-oxygen dilution combustion into a continuous process. Pulverized coal first undergoes activation in a circulating fluidized bed at around 850 °C, during which volatile nitrogen is released and partially reduced to N₂, with coal nitrogen conversion to N₂ ranging from 43.8% to 53.1%. This step significantly increases the specific surface area and pore development of char particles, providing more active sites for subsequent high-temperature reactions.

 

In the high-temperature purification stage operated at more than 150 °C above the ash flow temperature of each coal type, inorganic components are effectively separated with removal rates between 62% and 85%. Coal is converted into high-temperature gaseous fuel dominated by CO and H₂, while char nitrogen is extensively released and reduced. The conversion of coal nitrogen to N₂ reaches 93.6%–96.6% in this section, creating favorable conditions for low-pollutant combustion.

 

The high-temperature gas–solid fuel then enters the combustion chamber and realizes MILD combustion through multi-stage staged air distribution. In the reduction zone, NH₃ is completely converted to N₂, and the remaining char nitrogen is gradually released and reduced, lifting coal nitrogen conversion to N₂ above 99.6%. The oxidation zone completes char burnout with controlled temperature and mixing intensity to limit NOâ‚“ formation.

 

Tests using three coal types show that raw NOâ‚“ emissions at the furnace outlet are 34.6 mg·m⁻³ for Shenmu bituminous coal, 42.1 mg·m⁻³ for Beishan lignite, and 28.4 mg·m⁻³ for Yihua coal. Combustion efficiency remains above 99.6% across all tested fuels under the low-load condition. The system demonstrates stable operation and consistent performance, supporting the feasibility of this approach for clean coal utilization in power systems with high renewable penetration.

 

The study clarifies the transformation pathways of fuel-nitrogen throughout activation, purification, and MILD combustion, providing a technical route for improving operational flexibility and reducing pollutant emissions in coal-fired units under low-load conditions.

 

The paper “A Novel Coal Purification-Combustion Technology: Purification Characteristics and Ultra-Low Nitrogen Combustion at Low Load,” is authored by Shaobo Yang, Shaobo Han, Ruifang Cui, Linxuan Li, Chen Liang, Shuai Guo, Neng Fang, Wei Li, Qiangqiang Ren. Full text of the open access paper: https://doi.org/10.1016/j.eng.2025.09.026. For more information about Engineering, visit the website at https://www.sciencedirect.com/journal/engineering.

MIT researchers develop MFRNet digital twin for efficient industrial combustion system optimization




Higher Education Press
The general workflow of building digital twin for multi-field reconstruction, scalar prediction and multi-objective optimization based on MFRNet. 

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The general workflow of building digital twin for multi-field reconstruction, scalar prediction and multi-objective optimization based on MFRNet.

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Credit: Linzheng Wang, Yaojun Li, Sili Deng





A research team from the Massachusetts Institute of Technology has introduced a data-driven digital twin framework named Multi-Field Reconstruction Net (MFRNet) for industrial-scale combustion systems, aiming to support low-carbon energy transition with improved data efficiency and multi-task integration. The work was published in Engineering, providing a scalable solution for 3D multi-physical field reconstruction, emission prediction, and operational optimization under limited high-fidelity data conditions.

 

Against the background of growing use of carbon-neutral fuels such as biomass in combustion facilities, researchers note that conventional digital twin approaches often separate reconstruction and optimization processes, and demand extensive high-fidelity 3D simulation data that is computationally costly to generate. The MFRNet framework integrates dimension expansion, variable extension, and dynamic feature fusion to address these limitations, unifying multi-field reconstruction and multi-objective optimization within one machine learning pipeline.

 

In the validation using an industrial biomass grate furnace, the team constructed a hybrid dataset including 288 low-fidelity 2D cases covering eight physical fields and 48 high-fidelity 3D cases covering eleven physical fields. The model is first pre-trained on low-fidelity 2D data to explore the high-dimensional condition space, then fine-tuned on a small set of 3D data through dimension expansion to capture z-direction heterogeneity and boundary effects. Variable extension modules further infer NOâ‚“-related species distributions including NO, HCN, and NH₃ by reusing latent features from core combustion variables learned during pre-training.

 

The study shows that MFRNet supports multi-modal inputs consisting of operational parameters and sparse temperature measurements, aligned via contrastive learning to enable robust reconstruction even with partial input information. By leveraging intermediate features from the reconstruction stage, the framework enhances scalar prediction for key indicators such as CO and NO emissions at the furnace outlet. The fused features improve prediction accuracy compared with direct neural network mapping, supporting reliable response surface construction.

 

The trained digital twin is applied to multi-objective optimization using the NSGA‑II algorithm, targeting minimized CO and NO emissions under fixed capacity conditions. The optimization generates Pareto fronts that reveal trade-offs between combustion efficiency and pollutant control, supporting the identification of practical operating strategies. The framework maintains high precision in 3D multi-field reconstruction while substantially reducing dependence on computationally expensive 3D simulations, showing adaptability to diverse industrial combustion systems.

 

This integrated digital twin approach offers a data-efficient pathway for active control and real-time optimization of modern combustion facilities, supporting stable operation and low-emission performance in the shift toward low-carbon energy systems.

 

The paper “Building Digital Twin for 3D Multi-Field Reconstruction and Optimization of Industrial-Scale Combustion Systems,” is authored by Linzheng Wang, Yaojun Li, Sili Deng. Full text of the open access paper: https://doi.org/10.1016/j.eng.2025.08.020. For more information about Engineering, visit the website at https://www.sciencedirect.com/journal/engineering.

Flue gas-driven molten-salt heat exchanger boosts flexibility of coal-fired power plants





Higher Education Press

Concept of the heat storage system integrated with a coal-fired power plant. 

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Concept of the heat storage system integrated with a coal-fired power plant.

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Credit: Jinliang Xu, Hongliang Su et al.





A new study published in Engineering introduces a flue gas‑driven molten‑salt‑heat‑exchanger (MSHE) designed to enhance the operating flexibility of coal‑fired power plants, supporting grid stability amid growing renewable energy integration. This work marks the first experimental investigation into using furnace flue gas directly to drive a molten‑salt heat storage system, offering an alternative to conventional steam‑driven configurations.

 

The research addresses the need for improved load‑following capability in coal‑fired units, which traditionally face constraints in ramping speed and operational stability when balancing intermittent wind and solar generation. Unlike steam‑vapor‑driven molten‑salt systems, the flue gas‑driven approach eliminates pinch temperature limitations (PTL) associated with phase‑change heat transfer and simplifies system layout by requiring only a single heat exchanger. The MSHE employs three key design innovations: finned tubes to balance thermal resistance between flue gas and molten salt, a weak inclination angle to enable gravity‑driven drainage of molten salt during shutdown, and a modular structure to promote uniform temperature distribution at the tube bundle outlet.

 

Researchers designed, fabricated, and tested a 300 kW MSHE prototype coupled with a 10 MW furnace. Experimental results show measured overall heat transfer coefficients agree with model predictions within a deviation of less than 10%, and the unit achieved a thermal power of 320 kW, exceeding the design target. A new heat transfer correlation for molten salt was developed across a wide range of Reynolds numbers, supporting accurate performance prediction for engineering scale‑up. The modular design limited temperature deviations among different tubes to below 4 K, reducing risks of local overheating and molten salt decomposition.

 

The system supports both heat storage and heat compensation modes, using flue gas to offset heat losses from the storage system to the surroundings and lowering auxiliary electricity consumption during standby periods. Transient tests show stable transitions between operating states within 180 to 600 seconds, supporting responsive control under variable conditions. Long‑term testing over one year revealed no significant degradation in heat transfer or flow performance, confirming operational robustness.

 

Based on prototype data, a 10 MW MSHE has been designed and integrated into a 350 MWe coal‑fired power plant, helping the unit achieve a load variation rate of 6% Pe/min, comparable to gas turbine levels. Compared with steam extraction schemes, the flue gas route delivers higher round‑trip efficiency and a simpler system structure, reducing investment complexity while maintaining reliable heat storage and release. The technology provides a practical pathway to upgrade conventional coal‑fired units for more flexible grid support in low‑carbon energy systems.

 

The paper “Developing Flue Gas-Driven Molten-Salt-Heat-Exchanger for Flexible Operation of Coal-Fired Power Plant,” is authored by Jinliang Xu, Hongliang Su, Xinyu Dong, Xiongjiang Yu, Chao Liu, Yan Wang, Jian Xie, Wei Wang, Yupu Yu, Qinghua Wang, Yuguang Niu, Jizhen Liu, Ying Huang, Zhengshun Zhang, Anyou Dong, Yan Pan, Hao Wu. Full text of the open access paper: https://doi.org/10.1016/j.eng.2025.09.001. For more information about Engineering, visit the website at https://www.sciencedirect.com/journal/engineering.