The existing 2D settlement monitoring systems for utility tunnels are heavily reliant on manual interpretation of deformation data and empirical predictionmodels.Consequently,early anomalies(e.g.,minor cracks)are ofte...The existing 2D settlement monitoring systems for utility tunnels are heavily reliant on manual interpretation of deformation data and empirical predictionmodels.Consequently,early anomalies(e.g.,minor cracks)are often misjudged,and warnings lag by about 24 h without automated spatial localization.This study establishes a technical framework for requirements analysis,architectural design,and data-integration protocols.Revit parametric modelling is used to build a 3D tunnel model with structural elements,pipelines and 18 monitoring points(for displacement and joint width).Custom Revit API code integrated real-time sensor data into the BIM platform via an automated pipeline.The system achieved a spatial accuracy of±1 mm in locating deformation hotspots.Notifications are triggered within 10 s of anomaly detection,and the system renders 3D risk propagation paths in real-time.Realtime 3D visualization of risk propagation paths is also facilitated.The efficacy of the solution was validated in a Ningbo utility tunnel project,where it was demonstrated that it eliminates human-dependent judgment errors and reduces warning latency by 99.9%compared to conventional methods.The BIM-IoT integrated approach,which enables millimetre-level precision in risk identification and near-instantaneous response,establishes a new paradigm for intelligent infrastructure safety management.展开更多
Grain boundary diffusion technology is pivotal in the preparation of high-performance NdFeB magnets.This study investigates the factors that affect the efficiency of grain boundary diffusion,starting from the properti...Grain boundary diffusion technology is pivotal in the preparation of high-performance NdFeB magnets.This study investigates the factors that affect the efficiency of grain boundary diffusion,starting from the properties of the diffusion matrix.Through the adjustment of the sintering process,we effectively prepared magnets with varied densities that serve as the matrix for grain boundary diffusion with TbH,diffusion.The mobility characteristics of the Nd-rich phase during the densification stage are leveraged to ensure a more extensive distribution of heavy rare earth elements within the magnets.According to the experimental results,the increase in coercivity of low-density magnets after diffusion is significantly greater than that of relatively high-density magnets.The coercivity values measured are 805.32 kA/m for low-density magnets and 470.3 kA/m for high-density magnets.Additionally,grain boundary diffusion notably enhances the density of initial low-density magnets,addressing the issue of low density during the sintering stage.Before the diffusion treatment,the Nd-rich phases primarily concentrate at the triangular grain boundaries,resulting in an increased number of cavity defects in the magnets.These cavity defects contain atoms in a higher energy state,making them more prone to transition.Consequently,the diffusion activation energy at the void defects is lower than the intracrystalline diffusion activation energy,accelerating atom diffusion.The presence of larger cavities also provides more space for atom migration,thereby promoting the diffusion process.After the diffusion treatment,the proportion of bulk Nd-rich phases significantly decreases,and they infiltrate between the grains to fill the cavity defects,forming continuous fine grain boundaries.Based on these observations,the study aims to explore how to utilize this information to develop an efficient technique for grain boundary diffusion.展开更多
As an essential part of the urban infrastructure,underground utility tunnels have a long service life,complex structural performance evolution and dynamic changes both inside and outside the tunnel.These combined fact...As an essential part of the urban infrastructure,underground utility tunnels have a long service life,complex structural performance evolution and dynamic changes both inside and outside the tunnel.These combined factors result in a wide variety of disaster risks during the operation and maintenance phase,which make risk management and control particularly challenging.This work first reviews three common representative disaster factors during the operation and maintenance period:settlement,earthquakes,and explosions.It summarizes the causes of disasters,key technologies,and research methods.Then,it delves into the research on the intelligent operation and maintenance architecture for utility tunnels.Additionally,it explores the data challenges,monitoring technologies,and management platform architectures faced during the operation and maintenance process.This work provides new research perspectives for the long-term,healthy,and sustainable development of utility tunnels,which serve as the underground arteries of cities.展开更多
Efficient edge caching is essential for maximizing utility in video streaming systems,especially under constraints such as limited storage capacity and dynamically fluctuating content popularity.Utility,defined as the...Efficient edge caching is essential for maximizing utility in video streaming systems,especially under constraints such as limited storage capacity and dynamically fluctuating content popularity.Utility,defined as the benefit obtained per unit of cache bandwidth usage,degrades when static or greedy caching strategies fail to adapt to changing demand patterns.To address this,we propose a deep reinforcement learning(DRL)-based caching framework built upon the proximal policy optimization(PPO)algorithm.Our approach formulates edge caching as a sequential decision-making problem and introduces a reward model that balances cache hit performance and utility by prioritizing high-demand,high-quality content while penalizing degraded quality delivery.We construct a realistic synthetic dataset that captures both temporal variations and shifting content popularity to validate our model.Experimental results demonstrate that our proposed method improves utility by up to 135.9%and achieves an average improvement of 22.6%compared to traditional greedy algorithms and long short-term memory(LSTM)-based prediction models.Moreover,our method consistently performs well across a variety of utility functions,workload distributions,and storage limitations,underscoring its adaptability and robustness in dynamic video caching environments.展开更多
This study introduces a fund recommendation system based on the ε-greedy algorithm and an incremental learning framework.This model simulates the interaction process when customers browse the web-pages of fund produc...This study introduces a fund recommendation system based on the ε-greedy algorithm and an incremental learning framework.This model simulates the interaction process when customers browse the web-pages of fund products.Customers click on their preferred fund products when visiting a fund recommendation web-page.The system collects customer click sequences to continually estimate and update their utility function.The system generates product lists using the ε-greedy algorithm,where each product on the list has the probability of 1-ε of being selected as an exploitation strategy,and the probability of ε is chosen as the exploration strategy.We perform a series of numerical tests to evaluate the estimation performance with different values of ε.展开更多
The feasibility of using an ANN method to predict the mercury emission and speciation in the flue gas of a power station under un-tested combustion/operational conditions is evaluated. Based on existing field testing ...The feasibility of using an ANN method to predict the mercury emission and speciation in the flue gas of a power station under un-tested combustion/operational conditions is evaluated. Based on existing field testing datasets for the emissions of three utility boilers, a 3-layer back-propagation network is applied to predict the mercury speciation at the stack. The whole prediction procedure includes： collection of data, structuring an artificial neural network （ANN） model, training process and error evaluation. A total of 59 parameters of coal and ash analyses and power plant operating conditions are treated as input variables, and the actual mercury emissions and their speciation data are used to supervise the training process and verify the performance of prediction modeling. The precision of model prediction （ root- mean-square error is 0. 8 μg/Nm3 for elemental mercury and 0. 9 μg/Nm3 for total mercury） is acceptable since the spikes of semi- mercury continuous emission monitor （SCEM） with wet conversion modules are taken into consideration.展开更多
In the base of utility and marginal utility,the article put forwardthe concept of utility and marginal utilityof educational outlay and the theory of them,and analyzed the actuality of educational resource deployment ...In the base of utility and marginal utility,the article put forwardthe concept of utility and marginal utilityof educational outlay and the theory of them,and analyzed the actuality of educational resource deployment in ourcountry,gave some advice about howtoi mprove our educational resource deployment of compulsory education.展开更多
CO_(2) capture and utilization(CCU)technologies have been recognized as crucial strategies for mitigating global warming,reducing carbon emission,and promoting resource circularity.As such,the design and development o...CO_(2) capture and utilization(CCU)technologies have been recognized as crucial strategies for mitigating global warming,reducing carbon emission,and promoting resource circularity.As such,the design and development of related materials have attracted considerable research attention.Carbon-based materials,characterized by tunable pore structures,abundant active sites,high specific surface area,and excellent chemical stability,demonstrate significant potential for applications in CO_(2) capture and utilization.This review systematically analyzes the adsorption behaviors and performance variations of typical carbon materials,including activated carbon,porous carbon,graphene,and carbon nanotubes during CO_(2) capture processes.Concerning CO_(2) utilization,emphasis is placed on recent advances in the catalytic applications of carbon-based materials in key reactions such as methanation,reverse water-gas shift,dry reforming of methane,and alcohol synthesis.Moreover,the benefits and drawbacks of carbon materials in terms of CO_(2) adsorption capacity,catalytic activity,and stability are thoroughly evaluated,and their potential applications in integrated CO_(2) capture and utilization technologies are discussed.Finally,key strategies for enhancing the performance of carbonaceous materials through structural modulation and surface modification are elucidated.This review aims to provide theoretical guidance for the future development and large-scale implementation of carbon-based materials in CCU technologies.展开更多
The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically in...The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically investigated.The structural characteristics and nickel anchoring capacity were analyzed using XRD,BET,FT-IR,H2-TPR,and ICP-OES.The results demonstrated that the crystallization temperature significantly affected the framework order of SBA-15 and the surface anchoring efficiency of Ni ions.The nickel utilization efficiency increased from 8.4%at 80℃ to 60.49%at 140℃,but then decreased to 47.25%at 160℃,indicating an optimal crystallization temperature window.This provides crucial guidance for tailoring high-performance metal-doped molecular sieves.The optimal catalyst exhibited excellent performance in the hydrogenation of 1,4-butynediol(BYD):the BYD conversion reached 97.25%with 88.99%selectivity of 1,4-butenediol(BED)within 5 h,and reached 99.73%with 87.34%selectivity of 1,4-butanediol(BDO)after 20 h reaction.These results revealed the critical role of crystallization temperature in metal utilization and provided theoretical support for designing highly active molecular sieve catalysts.展开更多
Citrus is the world's most produced fruit.With the rapid growth of citrus cultivation and processing industries globally,the volume of by-products,including dropped fruits,defective fruits,and waste generated duri...Citrus is the world's most produced fruit.With the rapid growth of citrus cultivation and processing industries globally,the volume of by-products,including dropped fruits,defective fruits,and waste generated during processing,has surged.Consequently,resource wastage and environmental pollution due to the low utilization rate of these by-products have become increasingly prominent issues.Currently,citrus by-products are directly utilized as seasonings,tea,and traditional Chinese medicine,or for the extraction of pectin,flavonoids,carotenoids,limonoids,essential oils,synephrine,and other functional ingredients.They are also processed into ethanol,citric acid,feed,and organic fertilizer through biomass fermentation.Despite these applications,the overall utilization rate of citrus by-products remains low.Additionally,there is a lack of key technologies and core equipment,and the production of high value-added functional products is limited.The future direction for citrus by-product utilization lies in green,low-carbon,high-efficiency,and high-value comprehensive recycling.To address the serious environmental pollution and recycling challenges posed by citrus rotting,it is proposed for the first time to develop new products and mold prevention strategies throughout the entire citrus supply chain-"Planting-field management-harvesting-transportation-storage"-to achieve a circular economy approach.This strategy aims to"Take from citrus and give back to citrus"effectively preventing and reducing citrus rotting.Furthermore,it can mitigate the significant economic losses caused by fruit decay and provide insights into the high-quality development of comprehensive citrus by-product utilization.展开更多
A batch of important national standards for CCUS released.Recently,State Administration for Market Regulation(SAMR)and National Standardization Administration of China(SAC)released 12 national standards for carbon cap...A batch of important national standards for CCUS released.Recently,State Administration for Market Regulation(SAMR)and National Standardization Administration of China(SAC)released 12 national standards for carbon capture,utilization and storage(CCUS),which will come into effect on July 1,2026.展开更多
BACKGROUND Drug utilization research has an important role in assisting the healthcare administration to know,compute,and refine the prescription whose principal objective is to enable the rational use of drugs.Resear...BACKGROUND Drug utilization research has an important role in assisting the healthcare administration to know,compute,and refine the prescription whose principal objective is to enable the rational use of drugs.Research in developing nations relating to the cost of treatment is scarce when compared with developed countries.Thus,the drug utilization research studies from developing nations are most needed,and their number has been growing.AIM To evaluate patterns of utilization of antipsychotic drugs and direct medical cost analysis in patients newly diagnosed with schizophrenia.METHODS The present study was observational in type and based on a retrospective cohort to evaluate patterns of utilization of antipsychotic drugs using World Health Organization(WHO)core prescribing indicators and anatomical therapeutic chemical/defined daily dose indicators.We also calculated direct medical costs for a period of 6 months.RESULTS This study has found that atypical antipsychotics are the mainstay of treatment for schizophrenia in every age group and subcategories of schizophrenia.The evaluation based on WHO prescribing indicators showed a low average number of drugs per prescription and low prescribing frequency of antipsychotics from the National List of Essential Medicines 2015 and the WHO Essential Medicines List 2019.The total mean drug cost of our study was 1396 Indian rupees.The total mean cost due to the investigation in our study was 1017.34 Indian rupees.Therefore,the total mean direct medical cost incurred on patients in our study was 4337.28 Indian rupees.CONCLUSION The information from the present study can be used for reviewing and updating treatment policy at the institutional level.展开更多
Space exploration and manufacturing are of critical importance for scientific advancement,technological innovation,national security,and the acquisition of extraterrestrial resources.In view of this,chemical and biolo...Space exploration and manufacturing are of critical importance for scientific advancement,technological innovation,national security,and the acquisition of extraterrestrial resources.In view of this,chemical and biological nano-/micro-/meso-scale manufacturing provide complementary approaches to overcome key space exploration challenges by enabling the in-situ production of essential life-support materials,propellants,and other resources.This review examines the origin and historical evolution of space manufacturing and the latest advances across different environments—from orbital space stations and the lunar surface to Mars and asteroids.It is structured to present the current state of research,outline key manufacturing strategies and technologies,assess the technical and environmental challenges,and discuss emerging trends and future directions.Besides,the potential applications of emerging technologies such as synthetic biology and artificial intelligence in overcoming the limitations of microgravity,limited resources,and extreme conditions are discussed.Ultimately,this integrative review could serve to guide future development,from advancing space science and disruptive manufacturing to enabling interdisciplinary and application-level innovations.展开更多
Biodiversity constitutes the fundamental cornerstone of ecosystem stability and resilience,furnishing indispensable services that encompass food production,the provision of clean water,climate regulation and the contr...Biodiversity constitutes the fundamental cornerstone of ecosystem stability and resilience,furnishing indispensable services that encompass food production,the provision of clean water,climate regulation and the control of disease.Nonetheless,the planet is currently experiencing an unprecedented biodiversity crisis.展开更多
Among the “three data rights,” the data utilization right has been persistently overlooked, and is similar to a neglected “middle child” in the context of the data rights family. However, it is precisely during th...Among the “three data rights,” the data utilization right has been persistently overlooked, and is similar to a neglected “middle child” in the context of the data rights family. However, it is precisely during the stages of processing and utilization that data undergoes its transformations and where its economic value is ultimately created. A series of recent policy documents on treating data as a factor of production have emphasized that the building of a scientific data property rights system requires a fair and efficient mechanism for benefit distribution, which provides reasonable preference for creators of data value and use value in terms of the income generated by data elements. Constrained by the inertial thinking of property right logic, the data utilization right is often regarded as a “transitional fulcrum” wherein the holders of data resources have to authorize the operators of data products to realize data value thereby. In the future structural design and implementation of the coordination mechanism for the property right system against the backdrop of the data factor-oriented reform, the establishment of data processing and utilization as an independent right will require the implementation of two core initiatives: first, attaching importance to the independent protection of the benefit distribution;second, implementing risk regulation for data security through optimization of governance. These two initiatives will serve as the key for optimizing the data factor governance system and accelerating the release of data value.展开更多
Targeting Chang'E-8 mission'in-situ resource utilization(ISRU)for sustainable lunar habitats,laser powder bed fusion(LPBF)provides a viable pathway for in-situ additive manufacturing of lunar regolith.To eluci...Targeting Chang'E-8 mission'in-situ resource utilization(ISRU)for sustainable lunar habitats,laser powder bed fusion(LPBF)provides a viable pathway for in-situ additive manufacturing of lunar regolith.To elucidate mission relevant mechanical behavior and failure mechanisms of LPBF fabricated lunar regolith simulants,mare type and highland type simulant specimens were produced.Microstructural characterization,mechanical test coupled with three-dimensional digital image correlation(3D-DIC),and an energy-dissipation framework were employed for comprehensive analysis.The pristine highland specimens achieved 5.79 MPa and a peak strain of 0.13(50 mm×50 mm×30 mm),significantly outperforming their mare counterparts.Wire-cutting to 20 mm×20 mm×20 mm lowered strength by~20%and peak strain to 0.04,indicating cutting-induced defects reduce ductility.All specimens displayed multipeaked stress–strain curves.3D-DIC revealed band-type strain localization in pristine highland samples,diffuse strain patterns in cut highland samples,and highly tortuous,network-type bands in mare samples;the anisotropy index was also quantified.Fragmented particles exhibited fractal dimensions ranging from 1.6 to 2.0(size 1.25–9 mm).Energy evolution progressed through three distinct stages:elastic energy storage,progressive energy dissipation delaying crack propagation,and final unstable collapse.An energy-based damage model was established and validated.The data and methods developed support Chang'E-8 missions'ISRU demonstrations and establish a transferable framework toward sustainable lunar habitats.展开更多
CO_(2)utilization powered by sustainable energy offers a promising route to mitigate carbon emissions while producing value-added chemicals[1].Among these pathways,CO_(2)hydrogenation is especially attractive because ...CO_(2)utilization powered by sustainable energy offers a promising route to mitigate carbon emissions while producing value-added chemicals[1].Among these pathways,CO_(2)hydrogenation is especially attractive because it integrates renewable H 2 with carbon resources,which have achieved notable success in producing methanol,CO,etc.[2,3].展开更多
The construction of lunar bases represents a crucial goal for long-term human residence on the Moon and future deep-space exploration. Vacuum sintering of lunar regolith for in-situ resource utilization(ISRU) is consi...The construction of lunar bases represents a crucial goal for long-term human residence on the Moon and future deep-space exploration. Vacuum sintering of lunar regolith for in-situ resource utilization(ISRU) is considered one of the most feasible strategies for early lunar infrastructure development. However, the extreme temperature fluctuations on the lunar surface pose potential threats to the structural stability of sintered regolith materials. To investigate the mechanical deterioration and damage mechanism of vacuum-sintered lunar regolith under extreme cryogenic-thermal cycling, lunar regolith simulants are used to fabricate specimens through vacuum sintering. A series of cryogenic-thermal cycling tests is designed, combined with uniaxial compression and X-ray CT scanning, to systematically analyze their macro-micro responses. The results show that with increasing extreme cryogenic-thermal cycles, the stress-strain curves evolve from typical brittle failure to quasiductile behavior, with uniaxial compressive strength and elastic modulus decreasing by approximately 33.86% and 61.98%, respectively. CT analyses reveal that the pore structure transforms from isolated pores to connected networks, with the pore volume fraction increasing from 13.33% to 22.64%, and the fractal dimension increases from 2.465 to 2.544, and stabilizes after multiple cycles. A significant negative correlation(R^(2)> 0.96) exists between pore structural complexity and mechanical performance. Based on these findings, a thermal fatigue damage mechanism dominated by thermal stress concentration due to mismatched thermal expansion coefficients among mineral phases is proposed. This study provides scientific insights for the design, durability evaluation, and ISRU-based construction of lunar surface infrastructure.展开更多
Carbon dioxide(CO_(2))is the main greenhouse gas(GHG)released by human activities.The substitution of fossil resources by biomass as a bio-renewable resource,has significant potential to reduce GHG emissions.The appro...Carbon dioxide(CO_(2))is the main greenhouse gas(GHG)released by human activities.The substitution of fossil resources by biomass as a bio-renewable resource,has significant potential to reduce GHG emissions.The approach to biomass,as the only true full-scale alternative to fossil resources,is progressing rapidly.Converting biomass into furanic compounds,as versatile platform chemicals for synthesizing a wide range of bio-based products is the cornerstone of sustainable technologies.The extensive body of this review combines the biomass valorization to furanic compounds by CO_(2)utilization and furanic compounds conversion by CO_(2)fixation.These processes can be strategically applied through both‘thermochemical’and‘electrochemical’pathways,by utilizing CO_(2)from the atmosphere or industrial emission point and returning it to the natural carbon cycle.In the thermochemical pathway CO_(2)acts as a carbon source(carboxylation and polymerization)or active reaction assistant in the biomass conversion(CO_(2)-assisted conversion),without altering its oxidation state,facilitating the synthesis of valuable products and polymers.Conversely,in the electrochemical pathway,CO_(2)can be used as a carbon source(electrocarboxylation)to give the corresponding carboxylic acid,or it can undergo reduction,yielding methanol,carbon monoxide(CO),formic acid,and analogous compounds,while on the other side,furanic compounds undergo oxidation yielding high-value-added chemicals.Finally,potential future research directions are suggested to promote CO_(2)utilization and fixation in the valorization of biomass-derived furanic compounds,and challenges facing further research are highlighted.展开更多
Understanding the interaction of Martian rocks and the environment is conducive to Mars in situ resource utilization(ISRU) and the search for natural H_(2) reservoirs. Here, we report an interesting finding: using a r...Understanding the interaction of Martian rocks and the environment is conducive to Mars in situ resource utilization(ISRU) and the search for natural H_(2) reservoirs. Here, we report an interesting finding: using a real Martian meteorite(NWA13190) and within Mars' temperature range(25℃), we confirmed spontaneous hydrogen generation from the reaction of water, CO_(2), and Martian rock—no external energy or catalysts required. The reaction produced hydrogen at ~4 ppm/day, stabilizing after 9 days, alongside newly formed carbonate and sulfate minerals absent in the original meteorite. Mechanistic analyses using XPS(X-ray photoelectron spectroscopy), M??ssbauer spectroscopy, and FTIR(Fourier transform infrared spectroscopy) revealed that Fe^(2+) in Fe TiO_(3) and FeS_(2)(not pyroxene) oxidized to Fe^(3+), driving water reduction to hydrogen. The buffer effect of CO_(2) sustained acidic conditions, enhancing Fe^(2+) release and H_(2) production. These results align with in situ Mars detections(e.g., Ca-sulfate veins by Curiosity). Compared with energy-intensive electrolysis-based ISRU, this geological process offers a more efficient H_(2) production pathway. It also provides theoretical support for natural hydrogen reservoirs on Mars and simultaneously advances understanding of Mars' early atmospheric evolution and potential life-supporting environments.展开更多
基金supported by the Scientific Research Projects of the Education Department of Zhejiang Province(Grant No.Y202454744)the Ningbo Public Welfare Science and Technology Project(Grant No.2024S077)+1 种基金International Sci-tech Cooperation Projects under the“Innovation Yongjiang 2035”Key R&D Programme(No.2024H019)the Ningbo Key R&D Program(Grant No.2024Z287).
文摘The existing 2D settlement monitoring systems for utility tunnels are heavily reliant on manual interpretation of deformation data and empirical predictionmodels.Consequently,early anomalies(e.g.,minor cracks)are often misjudged,and warnings lag by about 24 h without automated spatial localization.This study establishes a technical framework for requirements analysis,architectural design,and data-integration protocols.Revit parametric modelling is used to build a 3D tunnel model with structural elements,pipelines and 18 monitoring points(for displacement and joint width).Custom Revit API code integrated real-time sensor data into the BIM platform via an automated pipeline.The system achieved a spatial accuracy of±1 mm in locating deformation hotspots.Notifications are triggered within 10 s of anomaly detection,and the system renders 3D risk propagation paths in real-time.Realtime 3D visualization of risk propagation paths is also facilitated.The efficacy of the solution was validated in a Ningbo utility tunnel project,where it was demonstrated that it eliminates human-dependent judgment errors and reduces warning latency by 99.9%compared to conventional methods.The BIM-IoT integrated approach,which enables millimetre-level precision in risk identification and near-instantaneous response,establishes a new paradigm for intelligent infrastructure safety management.
基金Project supported by the National Natural Science Foundation of China(52361033)National Key Research and Development Program(2022YFB3505400)+3 种基金Ministry of Industry and Information Technology Heavy Rare Earth Special Use of Sintered NdFeB Project(TC220H06J)Academic and Technical Leaders in Major Disciplines in Jiangxi Province(2022BCJ23007)Jiangxi Province Science and Technology Cooperation Key Project(20212BDH80007)Jiangxi Graduate Student Innovation Special Fund Project(YC2023-B213)。
文摘Grain boundary diffusion technology is pivotal in the preparation of high-performance NdFeB magnets.This study investigates the factors that affect the efficiency of grain boundary diffusion,starting from the properties of the diffusion matrix.Through the adjustment of the sintering process,we effectively prepared magnets with varied densities that serve as the matrix for grain boundary diffusion with TbH,diffusion.The mobility characteristics of the Nd-rich phase during the densification stage are leveraged to ensure a more extensive distribution of heavy rare earth elements within the magnets.According to the experimental results,the increase in coercivity of low-density magnets after diffusion is significantly greater than that of relatively high-density magnets.The coercivity values measured are 805.32 kA/m for low-density magnets and 470.3 kA/m for high-density magnets.Additionally,grain boundary diffusion notably enhances the density of initial low-density magnets,addressing the issue of low density during the sintering stage.Before the diffusion treatment,the Nd-rich phases primarily concentrate at the triangular grain boundaries,resulting in an increased number of cavity defects in the magnets.These cavity defects contain atoms in a higher energy state,making them more prone to transition.Consequently,the diffusion activation energy at the void defects is lower than the intracrystalline diffusion activation energy,accelerating atom diffusion.The presence of larger cavities also provides more space for atom migration,thereby promoting the diffusion process.After the diffusion treatment,the proportion of bulk Nd-rich phases significantly decreases,and they infiltrate between the grains to fill the cavity defects,forming continuous fine grain boundaries.Based on these observations,the study aims to explore how to utilize this information to develop an efficient technique for grain boundary diffusion.
基金financially supported by the Scientific Research Projects of the Education Department of Zhejiang Province(Grant No.Y202454744)the Ningbo Public Welfare Science and Technology Project(Grant Nos.2023S007 and 2023S165)the Key Research and Development Program of Zhejiang(Grant No.2023C03183).
文摘As an essential part of the urban infrastructure,underground utility tunnels have a long service life,complex structural performance evolution and dynamic changes both inside and outside the tunnel.These combined factors result in a wide variety of disaster risks during the operation and maintenance phase,which make risk management and control particularly challenging.This work first reviews three common representative disaster factors during the operation and maintenance period:settlement,earthquakes,and explosions.It summarizes the causes of disasters,key technologies,and research methods.Then,it delves into the research on the intelligent operation and maintenance architecture for utility tunnels.Additionally,it explores the data challenges,monitoring technologies,and management platform architectures faced during the operation and maintenance process.This work provides new research perspectives for the long-term,healthy,and sustainable development of utility tunnels,which serve as the underground arteries of cities.
文摘Efficient edge caching is essential for maximizing utility in video streaming systems,especially under constraints such as limited storage capacity and dynamically fluctuating content popularity.Utility,defined as the benefit obtained per unit of cache bandwidth usage,degrades when static or greedy caching strategies fail to adapt to changing demand patterns.To address this,we propose a deep reinforcement learning(DRL)-based caching framework built upon the proximal policy optimization(PPO)algorithm.Our approach formulates edge caching as a sequential decision-making problem and introduces a reward model that balances cache hit performance and utility by prioritizing high-demand,high-quality content while penalizing degraded quality delivery.We construct a realistic synthetic dataset that captures both temporal variations and shifting content popularity to validate our model.Experimental results demonstrate that our proposed method improves utility by up to 135.9%and achieves an average improvement of 22.6%compared to traditional greedy algorithms and long short-term memory(LSTM)-based prediction models.Moreover,our method consistently performs well across a variety of utility functions,workload distributions,and storage limitations,underscoring its adaptability and robustness in dynamic video caching environments.
基金This research was supported by National Key R&D Program of China under No.2022YFA1004000National Natural Science Foundation of China under No.11991023 and 12371324.
文摘This study introduces a fund recommendation system based on the ε-greedy algorithm and an incremental learning framework.This model simulates the interaction process when customers browse the web-pages of fund products.Customers click on their preferred fund products when visiting a fund recommendation web-page.The system collects customer click sequences to continually estimate and update their utility function.The system generates product lists using the ε-greedy algorithm,where each product on the list has the probability of 1-ε of being selected as an exploitation strategy,and the probability of ε is chosen as the exploration strategy.We perform a series of numerical tests to evaluate the estimation performance with different values of ε.
基金The National Basic Research Program of China (973Program) (No.2006CB200302)the Natural Science Foundation of JiangsuProvince (No.BK2007224).
文摘The feasibility of using an ANN method to predict the mercury emission and speciation in the flue gas of a power station under un-tested combustion/operational conditions is evaluated. Based on existing field testing datasets for the emissions of three utility boilers, a 3-layer back-propagation network is applied to predict the mercury speciation at the stack. The whole prediction procedure includes： collection of data, structuring an artificial neural network （ANN） model, training process and error evaluation. A total of 59 parameters of coal and ash analyses and power plant operating conditions are treated as input variables, and the actual mercury emissions and their speciation data are used to supervise the training process and verify the performance of prediction modeling. The precision of model prediction （ root- mean-square error is 0. 8 μg/Nm3 for elemental mercury and 0. 9 μg/Nm3 for total mercury） is acceptable since the spikes of semi- mercury continuous emission monitor （SCEM） with wet conversion modules are taken into consideration.
文摘In the base of utility and marginal utility,the article put forwardthe concept of utility and marginal utilityof educational outlay and the theory of them,and analyzed the actuality of educational resource deployment in ourcountry,gave some advice about howtoi mprove our educational resource deployment of compulsory education.
基金Supported by National Key R&D Program of China(2025YFE0109700)the National Natural Science Foundation of China(52106150)。
文摘CO_(2) capture and utilization(CCU)technologies have been recognized as crucial strategies for mitigating global warming,reducing carbon emission,and promoting resource circularity.As such,the design and development of related materials have attracted considerable research attention.Carbon-based materials,characterized by tunable pore structures,abundant active sites,high specific surface area,and excellent chemical stability,demonstrate significant potential for applications in CO_(2) capture and utilization.This review systematically analyzes the adsorption behaviors and performance variations of typical carbon materials,including activated carbon,porous carbon,graphene,and carbon nanotubes during CO_(2) capture processes.Concerning CO_(2) utilization,emphasis is placed on recent advances in the catalytic applications of carbon-based materials in key reactions such as methanation,reverse water-gas shift,dry reforming of methane,and alcohol synthesis.Moreover,the benefits and drawbacks of carbon materials in terms of CO_(2) adsorption capacity,catalytic activity,and stability are thoroughly evaluated,and their potential applications in integrated CO_(2) capture and utilization technologies are discussed.Finally,key strategies for enhancing the performance of carbonaceous materials through structural modulation and surface modification are elucidated.This review aims to provide theoretical guidance for the future development and large-scale implementation of carbon-based materials in CCU technologies.
文摘The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically investigated.The structural characteristics and nickel anchoring capacity were analyzed using XRD,BET,FT-IR,H2-TPR,and ICP-OES.The results demonstrated that the crystallization temperature significantly affected the framework order of SBA-15 and the surface anchoring efficiency of Ni ions.The nickel utilization efficiency increased from 8.4%at 80℃ to 60.49%at 140℃,but then decreased to 47.25%at 160℃,indicating an optimal crystallization temperature window.This provides crucial guidance for tailoring high-performance metal-doped molecular sieves.The optimal catalyst exhibited excellent performance in the hydrogenation of 1,4-butynediol(BYD):the BYD conversion reached 97.25%with 88.99%selectivity of 1,4-butenediol(BED)within 5 h,and reached 99.73%with 87.34%selectivity of 1,4-butanediol(BDO)after 20 h reaction.These results revealed the critical role of crystallization temperature in metal utilization and provided theoretical support for designing highly active molecular sieve catalysts.
基金supported by the National Natural Science Foundation of China(82104340)。
文摘Citrus is the world's most produced fruit.With the rapid growth of citrus cultivation and processing industries globally,the volume of by-products,including dropped fruits,defective fruits,and waste generated during processing,has surged.Consequently,resource wastage and environmental pollution due to the low utilization rate of these by-products have become increasingly prominent issues.Currently,citrus by-products are directly utilized as seasonings,tea,and traditional Chinese medicine,or for the extraction of pectin,flavonoids,carotenoids,limonoids,essential oils,synephrine,and other functional ingredients.They are also processed into ethanol,citric acid,feed,and organic fertilizer through biomass fermentation.Despite these applications,the overall utilization rate of citrus by-products remains low.Additionally,there is a lack of key technologies and core equipment,and the production of high value-added functional products is limited.The future direction for citrus by-product utilization lies in green,low-carbon,high-efficiency,and high-value comprehensive recycling.To address the serious environmental pollution and recycling challenges posed by citrus rotting,it is proposed for the first time to develop new products and mold prevention strategies throughout the entire citrus supply chain-"Planting-field management-harvesting-transportation-storage"-to achieve a circular economy approach.This strategy aims to"Take from citrus and give back to citrus"effectively preventing and reducing citrus rotting.Furthermore,it can mitigate the significant economic losses caused by fruit decay and provide insights into the high-quality development of comprehensive citrus by-product utilization.
文摘A batch of important national standards for CCUS released.Recently,State Administration for Market Regulation(SAMR)and National Standardization Administration of China(SAC)released 12 national standards for carbon capture,utilization and storage(CCUS),which will come into effect on July 1,2026.
文摘BACKGROUND Drug utilization research has an important role in assisting the healthcare administration to know,compute,and refine the prescription whose principal objective is to enable the rational use of drugs.Research in developing nations relating to the cost of treatment is scarce when compared with developed countries.Thus,the drug utilization research studies from developing nations are most needed,and their number has been growing.AIM To evaluate patterns of utilization of antipsychotic drugs and direct medical cost analysis in patients newly diagnosed with schizophrenia.METHODS The present study was observational in type and based on a retrospective cohort to evaluate patterns of utilization of antipsychotic drugs using World Health Organization(WHO)core prescribing indicators and anatomical therapeutic chemical/defined daily dose indicators.We also calculated direct medical costs for a period of 6 months.RESULTS This study has found that atypical antipsychotics are the mainstay of treatment for schizophrenia in every age group and subcategories of schizophrenia.The evaluation based on WHO prescribing indicators showed a low average number of drugs per prescription and low prescribing frequency of antipsychotics from the National List of Essential Medicines 2015 and the WHO Essential Medicines List 2019.The total mean drug cost of our study was 1396 Indian rupees.The total mean cost due to the investigation in our study was 1017.34 Indian rupees.Therefore,the total mean direct medical cost incurred on patients in our study was 4337.28 Indian rupees.CONCLUSION The information from the present study can be used for reviewing and updating treatment policy at the institutional level.
基金supported by National Natural Science Foundation of China(22278241)a grant from the Institute Guo Qiang,Tsinghua University(2021GQG1016).
文摘Space exploration and manufacturing are of critical importance for scientific advancement,technological innovation,national security,and the acquisition of extraterrestrial resources.In view of this,chemical and biological nano-/micro-/meso-scale manufacturing provide complementary approaches to overcome key space exploration challenges by enabling the in-situ production of essential life-support materials,propellants,and other resources.This review examines the origin and historical evolution of space manufacturing and the latest advances across different environments—from orbital space stations and the lunar surface to Mars and asteroids.It is structured to present the current state of research,outline key manufacturing strategies and technologies,assess the technical and environmental challenges,and discuss emerging trends and future directions.Besides,the potential applications of emerging technologies such as synthetic biology and artificial intelligence in overcoming the limitations of microgravity,limited resources,and extreme conditions are discussed.Ultimately,this integrative review could serve to guide future development,from advancing space science and disruptive manufacturing to enabling interdisciplinary and application-level innovations.
基金supported by the Guangdong Basic and Applied Basic Research Foundation-Special Program on Biodiversity(2023B0303050001).
文摘Biodiversity constitutes the fundamental cornerstone of ecosystem stability and resilience,furnishing indispensable services that encompass food production,the provision of clean water,climate regulation and the control of disease.Nonetheless,the planet is currently experiencing an unprecedented biodiversity crisis.
文摘Among the “three data rights,” the data utilization right has been persistently overlooked, and is similar to a neglected “middle child” in the context of the data rights family. However, it is precisely during the stages of processing and utilization that data undergoes its transformations and where its economic value is ultimately created. A series of recent policy documents on treating data as a factor of production have emphasized that the building of a scientific data property rights system requires a fair and efficient mechanism for benefit distribution, which provides reasonable preference for creators of data value and use value in terms of the income generated by data elements. Constrained by the inertial thinking of property right logic, the data utilization right is often regarded as a “transitional fulcrum” wherein the holders of data resources have to authorize the operators of data products to realize data value thereby. In the future structural design and implementation of the coordination mechanism for the property right system against the backdrop of the data factor-oriented reform, the establishment of data processing and utilization as an independent right will require the implementation of two core initiatives: first, attaching importance to the independent protection of the benefit distribution;second, implementing risk regulation for data security through optimization of governance. These two initiatives will serve as the key for optimizing the data factor governance system and accelerating the release of data value.
基金supported by the Young Student Project of National Natural Science Foundation of China(No.525B2139)the National Key Research and Development Program of China(Nos.2023YFB3711300 and 2021YFF0500301)the Space Application System of China Manned Space Program(No.KJZ-YYWCL404)。
文摘Targeting Chang'E-8 mission'in-situ resource utilization(ISRU)for sustainable lunar habitats,laser powder bed fusion(LPBF)provides a viable pathway for in-situ additive manufacturing of lunar regolith.To elucidate mission relevant mechanical behavior and failure mechanisms of LPBF fabricated lunar regolith simulants,mare type and highland type simulant specimens were produced.Microstructural characterization,mechanical test coupled with three-dimensional digital image correlation(3D-DIC),and an energy-dissipation framework were employed for comprehensive analysis.The pristine highland specimens achieved 5.79 MPa and a peak strain of 0.13(50 mm×50 mm×30 mm),significantly outperforming their mare counterparts.Wire-cutting to 20 mm×20 mm×20 mm lowered strength by~20%and peak strain to 0.04,indicating cutting-induced defects reduce ductility.All specimens displayed multipeaked stress–strain curves.3D-DIC revealed band-type strain localization in pristine highland samples,diffuse strain patterns in cut highland samples,and highly tortuous,network-type bands in mare samples;the anisotropy index was also quantified.Fragmented particles exhibited fractal dimensions ranging from 1.6 to 2.0(size 1.25–9 mm).Energy evolution progressed through three distinct stages:elastic energy storage,progressive energy dissipation delaying crack propagation,and final unstable collapse.An energy-based damage model was established and validated.The data and methods developed support Chang'E-8 missions'ISRU demonstrations and establish a transferable framework toward sustainable lunar habitats.
文摘CO_(2)utilization powered by sustainable energy offers a promising route to mitigate carbon emissions while producing value-added chemicals[1].Among these pathways,CO_(2)hydrogenation is especially attractive because it integrates renewable H 2 with carbon resources,which have achieved notable success in producing methanol,CO,etc.[2,3].
基金supported by the National Natural Science Foundation of China (Grant Nos.U23A6018,42362034)the Applied Basic Research Foundation of Yunnan Province,China (Grant No.202401AS070068)。
文摘The construction of lunar bases represents a crucial goal for long-term human residence on the Moon and future deep-space exploration. Vacuum sintering of lunar regolith for in-situ resource utilization(ISRU) is considered one of the most feasible strategies for early lunar infrastructure development. However, the extreme temperature fluctuations on the lunar surface pose potential threats to the structural stability of sintered regolith materials. To investigate the mechanical deterioration and damage mechanism of vacuum-sintered lunar regolith under extreme cryogenic-thermal cycling, lunar regolith simulants are used to fabricate specimens through vacuum sintering. A series of cryogenic-thermal cycling tests is designed, combined with uniaxial compression and X-ray CT scanning, to systematically analyze their macro-micro responses. The results show that with increasing extreme cryogenic-thermal cycles, the stress-strain curves evolve from typical brittle failure to quasiductile behavior, with uniaxial compressive strength and elastic modulus decreasing by approximately 33.86% and 61.98%, respectively. CT analyses reveal that the pore structure transforms from isolated pores to connected networks, with the pore volume fraction increasing from 13.33% to 22.64%, and the fractal dimension increases from 2.465 to 2.544, and stabilizes after multiple cycles. A significant negative correlation(R^(2)> 0.96) exists between pore structural complexity and mechanical performance. Based on these findings, a thermal fatigue damage mechanism dominated by thermal stress concentration due to mismatched thermal expansion coefficients among mineral phases is proposed. This study provides scientific insights for the design, durability evaluation, and ISRU-based construction of lunar surface infrastructure.
基金the National Key R&D Program of China(No.2021YFC2101604)National Natural Science Foundation of China(Nos.U23A20123,22278339)+1 种基金Fujian Provincial Key Science and Technology Program of China(No.2022YZ037013)Xiamen University for the financial support.
文摘Carbon dioxide(CO_(2))is the main greenhouse gas(GHG)released by human activities.The substitution of fossil resources by biomass as a bio-renewable resource,has significant potential to reduce GHG emissions.The approach to biomass,as the only true full-scale alternative to fossil resources,is progressing rapidly.Converting biomass into furanic compounds,as versatile platform chemicals for synthesizing a wide range of bio-based products is the cornerstone of sustainable technologies.The extensive body of this review combines the biomass valorization to furanic compounds by CO_(2)utilization and furanic compounds conversion by CO_(2)fixation.These processes can be strategically applied through both‘thermochemical’and‘electrochemical’pathways,by utilizing CO_(2)from the atmosphere or industrial emission point and returning it to the natural carbon cycle.In the thermochemical pathway CO_(2)acts as a carbon source(carboxylation and polymerization)or active reaction assistant in the biomass conversion(CO_(2)-assisted conversion),without altering its oxidation state,facilitating the synthesis of valuable products and polymers.Conversely,in the electrochemical pathway,CO_(2)can be used as a carbon source(electrocarboxylation)to give the corresponding carboxylic acid,or it can undergo reduction,yielding methanol,carbon monoxide(CO),formic acid,and analogous compounds,while on the other side,furanic compounds undergo oxidation yielding high-value-added chemicals.Finally,potential future research directions are suggested to promote CO_(2)utilization and fixation in the valorization of biomass-derived furanic compounds,and challenges facing further research are highlighted.
基金supported by the National Natural Science Foundation of China (Grant Nos.41807188,42402285,51978537,52270165)the Fundamental Research Funds for the Central Universities (Grant No.2042021kf0201)Start-up Fund for Distinguished Scholars,Wuhan University (Grant Nos.1403-413100041,1403-600460022)。
文摘Understanding the interaction of Martian rocks and the environment is conducive to Mars in situ resource utilization(ISRU) and the search for natural H_(2) reservoirs. Here, we report an interesting finding: using a real Martian meteorite(NWA13190) and within Mars' temperature range(25℃), we confirmed spontaneous hydrogen generation from the reaction of water, CO_(2), and Martian rock—no external energy or catalysts required. The reaction produced hydrogen at ~4 ppm/day, stabilizing after 9 days, alongside newly formed carbonate and sulfate minerals absent in the original meteorite. Mechanistic analyses using XPS(X-ray photoelectron spectroscopy), M??ssbauer spectroscopy, and FTIR(Fourier transform infrared spectroscopy) revealed that Fe^(2+) in Fe TiO_(3) and FeS_(2)(not pyroxene) oxidized to Fe^(3+), driving water reduction to hydrogen. The buffer effect of CO_(2) sustained acidic conditions, enhancing Fe^(2+) release and H_(2) production. These results align with in situ Mars detections(e.g., Ca-sulfate veins by Curiosity). Compared with energy-intensive electrolysis-based ISRU, this geological process offers a more efficient H_(2) production pathway. It also provides theoretical support for natural hydrogen reservoirs on Mars and simultaneously advances understanding of Mars' early atmospheric evolution and potential life-supporting environments.
