Resourceful food waste treatment is essential for promoting the sustainable development of anaerobic digestion and realizing a circular economy.In this study,biogas residue(BR)was used as a feedstock to produce highva...Resourceful food waste treatment is essential for promoting the sustainable development of anaerobic digestion and realizing a circular economy.In this study,biogas residue(BR)was used as a feedstock to produce highvalue-added products(gas,tar,and char-derived high-performance adsorbents)using pyrolysis technology(at 400–800℃).CaCO_(3),the major component of ash,significantly improved the quality of the pyrolysis product by decomposing into CO_(2) and CaO.The gasification reaction of CO_(2) with coke generated substantial CO and facilitated the formation of a rich pore structure in the char.CaO improved tar quality by contributing to secondary cracking reactions and reducing water content.The composite material formed exhibited excellent performance in wastewater treatment,with a maximum methylene blue adsorption capacity of 969.30 mg/g.The maximum adsorption of heavy metals Cu^(2+),Pb^(2+),and Cd^(2+)was 175.44,244.93,and 199.50 mg/g,respectively.The ash fraction on the ash-biochar composite material adsorbent surface enhanced pollutant removal by providing an alkaline adsorption environment and more oxygen-based n-π interaction sites.The economic analysis showed that the high value-added products obtained from the pyrolysis of BR make this process more productive than land use.展开更多
The electromagnetic wave absorption of silicon carbide nanowires is improved by their uniform and diverse cross-structures.This study introduces a sustainable and high value-added method for synthesizing silicon carbi...The electromagnetic wave absorption of silicon carbide nanowires is improved by their uniform and diverse cross-structures.This study introduces a sustainable and high value-added method for synthesizing silicon carbide nanowires using lignite and waste silicon powder as raw materials through carbothermal reduction.The staggered structure of nanowires promotes the creation of interfacial polarization,impedance matching,and multiple loss mechanisms,leading to enhanced electromagnetic absorption performance.The silicon carbide nanowires demonstrate outstanding electromagnetic absorption capabilities with the minimum reflection loss of-48.09 d B at10.08 GHz and an effective absorption bandwidth(the reflection loss less than-10 d B)ranging from 8.54 to 16.68 GHz with a thickness of 2.17 mm.This research presents an innovative approach for utilizing solid waste in an environmentally friendly manner to produce broadband silicon carbide composite absorbers.展开更多
The electrocatalytic oxidation of ethylene glycol(EG)into high-value chemicals like glycolic acid(GA)is a crucial step for upcycling waste plastics.However,catalyst deactivation and low selectivity pose significant ch...The electrocatalytic oxidation of ethylene glycol(EG)into high-value chemicals like glycolic acid(GA)is a crucial step for upcycling waste plastics.However,catalyst deactivation and low selectivity pose significant challenges.This work presents the low-coordination PtBi nanosheets(LC-PtBi NSs),featuring a unique amorphous-crystalline heterostructure with a low coordination number of 2.3-2.5.They can exhibit exceptional mass activity(8.3 A mg_(Pt)^(-1))and stability(maintaining 88.7%of initial activity after running for 3600 s)of the EG oxidation reaction(EGOR).They also achieve over 90%apparent selectivity for EG-to-GA conversion at low potentials(<0.7 V vs.RHE)and even more than 100-h continuous electrolysis.Density fu nctional theory(DFT)calculations reveal that the low-coordination PtBi heterogeneous interface is responsible for the high coverage of OH_(ad) species and weakened adsorption of carbonaceous intermediates on LC-PtBi NSs,thereby promoting the direct oxidation of C_(2) intermediates to GA.This work demonstrates a strategy of doping-mediated catalytic interface regulation and electron density rearrangement,offering insights for designing efficient Pt-based electrocatalysts toward selective oxidation of small molecules.展开更多
In this review,the synthesis,functions,and applications of the polymers containing germanium and tin,which are heavy group 14 elements,in their polymer frameworks are summarized.Germanium and tin can form similar skel...In this review,the synthesis,functions,and applications of the polymers containing germanium and tin,which are heavy group 14 elements,in their polymer frameworks are summarized.Germanium and tin can form similar skeletal structures with their homologues carbon and silicon,whereas the polymers containing germanium and tin show unique properties derived from their large atomic radii and weak binding energies.For example,polygermane and polystannane exhibited light absorption in the UV–visible region and conductivity because of theσ-conjugation through the polymer main-chain constructed byσ-bonds between heavy elements.Theσ-conjugation was affected by the conformational change of the polymer main-chain,and thermochromic properties can be induced.Furthermore,the weak bonds were able to be cleaved homolytically upon photoirradiation,and radicals were subsequently generated.By incorporating hypervalent heavy elements into theπ-conjugated system,it was possible to modulate the electronic structures of theπ-conjugated system throughσ*–π*conjugation with highly coordinated elements.Finally,applications for organic solar cells,organic lightemitting materials,and chemical sensors have been achieved.Herein,representative synthetic methods and unique properties for creating smart materials with germanium and tin will be explained.展开更多
The Martian core mainly contains iron,nickel and some light elements.However,controversies remain about the structure and chemical composition of the Martian core due to a lack of samples and marsquake data.Recently,t...The Martian core mainly contains iron,nickel and some light elements.However,controversies remain about the structure and chemical composition of the Martian core due to a lack of samples and marsquake data.Recently,the InSight lander collected long-term marsquake data,which improved the Martian interior structure model.B ased on the preliminary analysis of marsquake data,Mars has a molten liquid core with a radius of around 1700 km.As the Martian core has a smaller density and lower temperature than pure iron at corresponding pressure and temperature conditions,some light elements are introduced to reduce the density and liquidus temperature.With various methods for seismic analysis,in-situ high-pressure and high-temperature experiments,and first-principal calculations,the Martian core composition and evolution models have been updated in the past few years.Here,we review those studies on the light elements in the Martian core from four aspects including(1)high-temperature and high-pressure experiments,(2)marsquake data,(3)mineral physics model with molecular dynamics simulations and(4)cosmochemistry investigation.We discussed the effect of different light elements on the Martian core s density,sound velocity and liquidus temperature.Moreover,the review examines the varieties,abundances and forms of light elements in the Martian core.展开更多
Against the backdrop of profound restructuring in the global industrial and supply chains,data elements have emerged as a critical force driving the transformation of enterprises'new quality productive forces.To a...Against the backdrop of profound restructuring in the global industrial and supply chains,data elements have emerged as a critical force driving the transformation of enterprises'new quality productive forces.To address the ambiguity surrounding its micro-level empowerment mechanism,this paper empirically examines the impact of data elements on enterprises'new quality productive forces and its transmission channels using panel data of Chinese A-share listed firms from 2014 to 2023.The results show that data elements significantly improve the level of enterprises'new quality productive forces.Heterogeneity analysis indicates that this promotional effect is more pronounced in non-state-owned enterprises,large-scale enterprises,and low-leverage enterprises.Mechanism tests confirm that data elements empower new quality productive forces through three paths:enhancing enterprise innovation capability,improving internal operational efficiency,and promoting inter-firm collaboration efficiency.This study provides empirical evidence for understanding the micro-level empowerment logic of data elements and offers theoretical references and practical implications for advancing the deep integration of the digital economy and the real economy.展开更多
The influence of varying levels of impurity elements on the hot corrosion resistance of the DD98M alloy in Na_(2)SO_(4)+NaCl salt at 950℃ was investigated.The results indicate that the corrosion resistance of the DD9...The influence of varying levels of impurity elements on the hot corrosion resistance of the DD98M alloy in Na_(2)SO_(4)+NaCl salt at 950℃ was investigated.The results indicate that the corrosion resistance of the DD98M alloy significantly decreases with an increase in impurity content,and the presence of nitrogen leads to an increase in alloy porosity.These porosities promote the rapid diffusion of molten salt and oxygen into the alloy,resulting in a bilateral diffusion of oxygen and sulfur,which leads to an accumulation of these elements at the oxide−matrix interface.This process contributes to the formation and propagation of interfacial cracks.A growth model was developed for hot corrosion products in alloys with varying impurity elements.展开更多
The buoyancy-induced flow constitutes a core scientific issue for thermal management of electronic devices and thermal design of energy systems,where accurate characterization of flow and heat transfer is essential to...The buoyancy-induced flow constitutes a core scientific issue for thermal management of electronic devices and thermal design of energy systems,where accurate characterization of flow and heat transfer is essential to improve thermal efficiency.In this work,buoyancy-induced flow above two heating elements flush-mounted at the bottom of a square enclosure containing air is numerically investigated over a range of Rayleigh numbers(0<Ra≤1.5×10^(8)),with a focus on equal and unequal heat flux conditions under a constraint of constant total thermal energy input.Distinct flow transitions are observed in both cases,leading to the identification of three flow regimes:Steady,periodic unsteady,and chaotic unsteady.Two types of periodic flows are distinguished,in which the first is a periodic flow dominated by a fundamental frequency(FF)and its integer-multiple frequencies(INTMF),while the second is a more complex periodic flow featuring FF,INTMF,and their sub-harmonics.The transitions between these regimes are affected by the relative heat flux of the two heaters.When the heat flux of the two heaters is unequal,the range of Rayleigh numbers corresponding to periodic flow is suppressed.It is also found that the time-averaged maximum temperature of the strong heater increases more rapidly with Ra,while that of the weak heater increases more slowly,reflecting the interaction between buoyancy-driven flow dynamics and asymmetric heat input.Analysis of the time-averaged Nusselt number demonstrates that heat dissipation from the isothermal walls remains roughly equivalent,even when the heat flux of the two heaters differs by a factor of two.These findings highlight the critical roles of Rayleigh number,the number of heaters,and the heat flux ratio of the heaters in determining heat transfer and flow characteristics for buoyancy-driven convection systems,providing important theoretical support and design references for engineering scenarios such as electronic devices and design of new energy systems.展开更多
Effects of alloying elements Ni,Co,Mn,Cr,and H on the stacking fault energy(SFE)ofγ-Fe and its microscopic mechanisms were systematically investigated.Generalized SFE calculations show that individual alloying elemen...Effects of alloying elements Ni,Co,Mn,Cr,and H on the stacking fault energy(SFE)ofγ-Fe and its microscopic mechanisms were systematically investigated.Generalized SFE calculations show that individual alloying elements Ni,Co,and H increase SFE ofγ-Fe,whereas Mn and Cr decrease SFE.The influence of alloying elements on SFE exhibits short-range characteristics.The effect of synergistic interaction of alloying elements and H on SFE was further investigated.Results show that the co-alloying of Ni/Co with H exacerbates the effect of H on the increase in SFE.In contrast,the synergistic effect of Mn/Cr with H tends to inhibit H from the increasing SFE.Finally,the electronic structure analysis elucidated the microscopic mechanism of the change in SFE.Alloying elements modulate SFE by changing the interatomic charge density at the stacking fault plane and the density of states of the stacking fault structure at the Fermi level.The present results add to the knowledge of alloying related influence on the mechanical property and hydrogen embrittlement ofγ-Fe.展开更多
On the stone-paved lanes of Songyang County that date back to ancient times,morning mist lingered as a faint fragrance of tea wafted from a century-old house.Inside,Yang Junjie,a tea maker born in the 1980s,worked def...On the stone-paved lanes of Songyang County that date back to ancient times,morning mist lingered as a faint fragrance of tea wafted from a century-old house.Inside,Yang Junjie,a tea maker born in the 1980s,worked deftly at the stove,his hands moving swiftly over the scorching iron wok as tender green tea leaves dance between his fingers.展开更多
Fig.3.(a)α-particle energy spectra,and(b)decay-time distributions on a logarithmic scale for the observed 288Mc and its descendant nuclei.In the panel(a),the red histograms show the observed full-energy events,while ...Fig.3.(a)α-particle energy spectra,and(b)decay-time distributions on a logarithmic scale for the observed 288Mc and its descendant nuclei.In the panel(a),the red histograms show the observed full-energy events,while the corresponding blue histograms show the reconstructed events.The red smooth curves in panel(b)are the expected time distributions according to the corresponding half-lives extracted from this work.展开更多
We report the results of the experiment on synthesizing ^(287,288)Mc isotopes (Z=115) using the fusionevaporation reaction ^(243)Am(^(48)Ca,4n,3n)^(287,288)Mc at the Spectrometer for Heavy Atoms and Nuclear Structure-...We report the results of the experiment on synthesizing ^(287,288)Mc isotopes (Z=115) using the fusionevaporation reaction ^(243)Am(^(48)Ca,4n,3n)^(287,288)Mc at the Spectrometer for Heavy Atoms and Nuclear Structure-2(SHANS2),a gas-filled recoil separator located at the China Accelerator Facility for Superheavy Elements(CAFE2).In total,20 decay chains are attributed to ^(288)Mc and 1 decay chain is assigned to ^(287)Mc.The measured oa-decay properties of ^(287,288)Mc as well as its descendants are consistent with the known data.No additional decay chains originating from the 2n or 5n reaction channels were detected.The excitation function of the ^(243)Am(^(48)Ca,3n)^(288)Mc reaction was measured at the cross-section level of picobarn,which indicates the promising capability for the study of heavy and superheavy nuclei at the facility.展开更多
Neurodegenerative diseases cause great medical and economic burdens for both patients and society;however, the complex molecular mechanisms thereof are not yet well understood. With the development of high-coverage se...Neurodegenerative diseases cause great medical and economic burdens for both patients and society;however, the complex molecular mechanisms thereof are not yet well understood. With the development of high-coverage sequencing technology, researchers have started to notice that genomic repeat regions, previously neglected in search of disease culprits, are active contributors to multiple neurodegenerative diseases. In this review, we describe the association between repeat element variants and multiple degenerative diseases through genome-wide association studies and targeted sequencing. We discuss the identification of disease-relevant repeat element variants, further powered by the advancement of long-read sequencing technologies and their related tools, and summarize recent findings in the molecular mechanisms of repeat element variants in brain degeneration, such as those causing transcriptional silencing or RNA-mediated gain of toxic function. Furthermore, we describe how in silico predictions using innovative computational models, such as deep learning language models, could enhance and accelerate our understanding of the functional impact of repeat element variants. Finally, we discuss future directions to advance current findings for a better understanding of neurodegenerative diseases and the clinical applications of genomic repeat elements.展开更多
Value-added evaluation focuses on individual student growth by tracking changes in academic performance,skills,literacy,etc.,at different time points.It weakens horizontal comparisons and emphasizes vertical progress ...Value-added evaluation focuses on individual student growth by tracking changes in academic performance,skills,literacy,etc.,at different time points.It weakens horizontal comparisons and emphasizes vertical progress to more fairly reflect educational effectiveness.This evaluation method is particularly suitable for vocational education,effectively motivating students’learning enthusiasm and enhancing their self-confidence.Foreign research is represented by the Tennessee Value-Added Assessment System(TVAAS),widely used in evaluating school quality and teacher performance.Domestic research currently focuses on the theoretical construction,model establishment,optimization,and practical application of value-added evaluation,still facing significant challenges in data collection comprehensiveness and model adaptability.Aiming at current issues,this study focuses on exploring the application of artificial intelligence large models in student value-added evaluation from an evidence-based perspective,committed to constructing an innovative evidence-based value-added evaluation system.It aims to achieve precise assessment of students’learning effect“net value-added”through multi-source data collection,intelligent analysis,and personalized feedback.The system integrates outcome evaluation,process evaluation,value-added evaluation,and comprehensive evaluation to form a“four-in-one”dynamic evaluation framework,considering students’starting points,process performance,and final achievements.In the future,value-added evaluation needs to further expand the assessment of non-academic dimensions(such as professional literacy and social-emotional skills)and explore the application of non-linear models to promote the deepening and innovation of educational evaluation reform.展开更多
Producing steel requires large amounts of energy to convert iron ores into steel,which often comes from fossil fuels,leading to carbon emissions and other pollutants.Increasing scrap usage emerges as one of the most e...Producing steel requires large amounts of energy to convert iron ores into steel,which often comes from fossil fuels,leading to carbon emissions and other pollutants.Increasing scrap usage emerges as one of the most effective strategies for addressing these issues.However,typical residual elements(Cu,As,Sn,Sb,Bi,etc.)inherited from scrap could significantly influence the mechanical properties of steel.In this work,we investigate the effects of residual elements on the microstructure evolution and mechanical properties of a quenching and partitioning(Q&P)steel by comparing a commercial QP1180 steel(referred to as QP)to the one containing typical residual elements(Cu+As+Sn+Sb+Bi<0.3wt%)(referred to as QP-R).The results demonstrate that in comparison with the QP steel,the residual elements significantly refine the prior austenite grain(9.7μm vs.14.6μm)due to their strong solute drag effect,leading to a higher volume fraction(13.0%vs.11.8%),a smaller size(473 nm vs.790 nm)and a higher average carbon content(1.26 wt%vs.0.99 wt%)of retained austenite in the QP-R steel.As a result,the QP-R steel exhibits a sustained transformation-induced plasticity(TRIP)effect,leading to an enhanced strain hardening effect and a simultaneous improvement of strength and ductility.Grain boundary segregation of residual elements was not observed at prior austenite grain boundaries in the QP-R steel,primarily due to continuous interface migration during austenitization.This study demonstrates that the residual elements with concentrations comparable to that in scrap result in significant microstructural refinement,causing retained austenite with relatively higher stability and thus offering promising mechanical properties and potential applications.展开更多
Based on the educational evaluation reform,this study explores the construction of an evidence-based value-added evaluation system based on data-driven,aiming to solve the limitations of traditional evaluation methods...Based on the educational evaluation reform,this study explores the construction of an evidence-based value-added evaluation system based on data-driven,aiming to solve the limitations of traditional evaluation methods.The research adopts the method of combining theoretical analysis and practical application,and designs the evidence-based value-added evaluation framework,which includes the core elements of a multi-source heterogeneous data acquisition and processing system,a value-added evaluation agent based on a large model,and an evaluation implementation and application mechanism.Through empirical research verification,the evaluation system has remarkable effects in improving learning participation,promoting ability development,and supporting teaching decision-making,and provides a theoretical reference and practical path for educational evaluation reform in the new era.The research shows that the evidence-based value-added evaluation system based on data-driven can reflect students’actual progress more fairly and objectively by accurately measuring the difference in starting point and development range of students,and provide strong support for the realization of high-quality education development.展开更多
Liquid crystal Pacharatnam-Berry phase optical elements(PBOEs)have found promising applications in augmented reality and virtual reality because of their slim formfactor,lightweight,and high optical efficiency.However...Liquid crystal Pacharatnam-Berry phase optical elements(PBOEs)have found promising applications in augmented reality and virtual reality because of their slim formfactor,lightweight,and high optical efficiency.However,chromatic aberration remains a serious longstanding problem for diffractive optics,hindering their broader adoption.To overcome the chromatic aberrations for red,green and blue(RGB)light sources,in this paper,we propose a counterintuitive multi-twist structure to achieve narrowband PBOEs without crosstalk,which plays a vital role to eliminate the chromatic aberration.The performance of our designed and fabricated narrowband Pacharatnam-Berry lenses(PBLs)aligns well with our simulation results.Furthermore,in a feasibility demonstration experiment using a laser projector,our proposed PBL system indeed exhibits a diminished chromatic aberration as compared to a broadband PBL.Additionally,polarization raytracing is implemented to demonstrate the versatility of the multi-twist structure for designing any RGB wavelengths with high contrast ratios.This analysis explores the feasibility of using RGB laser lines and quantum dot light-emitting diodes.Overall,our approach enables high optical efficiency,low fabrication complexity,and high degree of design freedom to accommodate any liquid crystal material and RGB light sources,holding immense potential for widespread applications of achromatic PBOEs.展开更多
The data production elements are driving profound transformations in the real economy across production objects,methods,and tools,generating significant economic effects such as industrial structure upgrading.This pap...The data production elements are driving profound transformations in the real economy across production objects,methods,and tools,generating significant economic effects such as industrial structure upgrading.This paper aims to reveal the impact mechanism of the data elements on the“three transformations”(high-end,intelligent,and green)in the manufacturing sector,theoretically elucidating the intrinsic mechanisms by which the data elements influence these transformations.The study finds that the data elements significantly enhance the high-end,intelligent,and green levels of China's manufacturing industry.In terms of the pathways of impact,the data elements primarily influence the development of high-tech industries and overall green technological innovation,thereby affecting the high-end,intelligent,and green transformation of the industry.展开更多
Rare earth elements(REEs),with their unique magnetic,optical,and electrical properties,have become indispensable strategic resources.Widely applied in critical fields such as aviation,telecommunications,electronics,en...Rare earth elements(REEs),with their unique magnetic,optical,and electrical properties,have become indispensable strategic resources.Widely applied in critical fields such as aviation,telecommunications,electronics,energy,transportation,and medicine,REEs play a vital role in advancing technology and driving social and economic development.However,the REE industry faces numerous challenges,including unbalanced resource distribution,supply and demand imbalances,international competition,technological limitations,and associated environmental pollution.This paper,incorporating both the historical evolution and current state of the REE industry,provides a comprehensive examination of the chemistry,applications,resources,technologies,challenges,and prospects of REEs.Specifically,it analyzes China's REE industry,which holds the largest global reserves and production capacity.As a key feature,this paper introduces the Tai Chi model for sustainable development in the REE industry,offering an in-depth analysis of two primary approaches—mining and recycling;the four critical participants—governments,enterprises,researchers,and consumers;and the eight essential influencing factors—resources,energy,environment,policy,applications,technology,supply and demand,and economy.The Tai Chi model not only clarifies the responsibilities and significance of each individual but also highlights their interconnectedness,providing a compelling framework for envisioning the sustainable development of the REE industry.Moreover,the paper identifies the major challenges currently facing the industry and offers insights into the future development of REEs.As such,this work contributes to a deeper understanding of the multifaceted REE landscape and underscores the importance of sustainable practices to ensure REEs'lasting positive impact on the global industry.展开更多
As a new type of production factor in healthcare,healthcare data elements have been rapidly integrated into various health production processes,such as clinical assistance,health management,biological testing,and oper...As a new type of production factor in healthcare,healthcare data elements have been rapidly integrated into various health production processes,such as clinical assistance,health management,biological testing,and operation and supervision[1,2].Healthcare data elements include biolog.ical and clinical data that are related to disease,environ-mental health data that are associated with life,and operational and healthcare management data that are related to healthcare activities(Figure 1).Activities such as the construction of a data value assessment system,the devel-opment of a data circulation and sharing platform,and the authorization of data compliance and operation products support the strong growth momentum of the market for health care data elements in China[3].展开更多
基金supported by the National Natural Science Foundation of China(Nos.52192684,52270136,and U2340214).
文摘Resourceful food waste treatment is essential for promoting the sustainable development of anaerobic digestion and realizing a circular economy.In this study,biogas residue(BR)was used as a feedstock to produce highvalue-added products(gas,tar,and char-derived high-performance adsorbents)using pyrolysis technology(at 400–800℃).CaCO_(3),the major component of ash,significantly improved the quality of the pyrolysis product by decomposing into CO_(2) and CaO.The gasification reaction of CO_(2) with coke generated substantial CO and facilitated the formation of a rich pore structure in the char.CaO improved tar quality by contributing to secondary cracking reactions and reducing water content.The composite material formed exhibited excellent performance in wastewater treatment,with a maximum methylene blue adsorption capacity of 969.30 mg/g.The maximum adsorption of heavy metals Cu^(2+),Pb^(2+),and Cd^(2+)was 175.44,244.93,and 199.50 mg/g,respectively.The ash fraction on the ash-biochar composite material adsorbent surface enhanced pollutant removal by providing an alkaline adsorption environment and more oxygen-based n-π interaction sites.The economic analysis showed that the high value-added products obtained from the pyrolysis of BR make this process more productive than land use.
基金supported by the National Natural Science Foundation of China(No.52436008)the Inner Mongolia Science and Technology Projects,China(Nos.JMRHZX20210003 and 2023YFCY0009)+3 种基金the Huaneng Group Co Ltd.,China(No.HNKJ23-H50)the National Natural Science Foundation of China(No.22408044)the China Postdoctoral Science Foundation(No.2024M761877)the National Key R&D Program of China(No.SQ2024YFD2200039)。
文摘The electromagnetic wave absorption of silicon carbide nanowires is improved by their uniform and diverse cross-structures.This study introduces a sustainable and high value-added method for synthesizing silicon carbide nanowires using lignite and waste silicon powder as raw materials through carbothermal reduction.The staggered structure of nanowires promotes the creation of interfacial polarization,impedance matching,and multiple loss mechanisms,leading to enhanced electromagnetic absorption performance.The silicon carbide nanowires demonstrate outstanding electromagnetic absorption capabilities with the minimum reflection loss of-48.09 d B at10.08 GHz and an effective absorption bandwidth(the reflection loss less than-10 d B)ranging from 8.54 to 16.68 GHz with a thickness of 2.17 mm.This research presents an innovative approach for utilizing solid waste in an environmentally friendly manner to produce broadband silicon carbide composite absorbers.
基金supported by the National Natural Science Foundation of China(NSFC,No.22172121)the Fundamental Research Funds for the Central Universities(No.ZYN2025267)Southwest Minzu University。
文摘The electrocatalytic oxidation of ethylene glycol(EG)into high-value chemicals like glycolic acid(GA)is a crucial step for upcycling waste plastics.However,catalyst deactivation and low selectivity pose significant challenges.This work presents the low-coordination PtBi nanosheets(LC-PtBi NSs),featuring a unique amorphous-crystalline heterostructure with a low coordination number of 2.3-2.5.They can exhibit exceptional mass activity(8.3 A mg_(Pt)^(-1))and stability(maintaining 88.7%of initial activity after running for 3600 s)of the EG oxidation reaction(EGOR).They also achieve over 90%apparent selectivity for EG-to-GA conversion at low potentials(<0.7 V vs.RHE)and even more than 100-h continuous electrolysis.Density fu nctional theory(DFT)calculations reveal that the low-coordination PtBi heterogeneous interface is responsible for the high coverage of OH_(ad) species and weakened adsorption of carbonaceous intermediates on LC-PtBi NSs,thereby promoting the direct oxidation of C_(2) intermediates to GA.This work demonstrates a strategy of doping-mediated catalytic interface regulation and electron density rearrangement,offering insights for designing efficient Pt-based electrocatalysts toward selective oxidation of small molecules.
基金supported by Japan Society for the Promotion of Science(JSPS),a Grant-in-Aid for Scientific Research(B)(JP23K23398)(for M.G.)and(JP24K01570)(for K.T.).
文摘In this review,the synthesis,functions,and applications of the polymers containing germanium and tin,which are heavy group 14 elements,in their polymer frameworks are summarized.Germanium and tin can form similar skeletal structures with their homologues carbon and silicon,whereas the polymers containing germanium and tin show unique properties derived from their large atomic radii and weak binding energies.For example,polygermane and polystannane exhibited light absorption in the UV–visible region and conductivity because of theσ-conjugation through the polymer main-chain constructed byσ-bonds between heavy elements.Theσ-conjugation was affected by the conformational change of the polymer main-chain,and thermochromic properties can be induced.Furthermore,the weak bonds were able to be cleaved homolytically upon photoirradiation,and radicals were subsequently generated.By incorporating hypervalent heavy elements into theπ-conjugated system,it was possible to modulate the electronic structures of theπ-conjugated system throughσ*–π*conjugation with highly coordinated elements.Finally,applications for organic solar cells,organic lightemitting materials,and chemical sensors have been achieved.Herein,representative synthetic methods and unique properties for creating smart materials with germanium and tin will be explained.
基金financially supported by the National Natural Science Foundation of China(grant no.42120104005)Guizhou Provincial 2021 Science and Technology Subsidies(grant no.GZ2021SIG)+1 种基金Guizhou Provincial Science and Technology Projects(grant nos.ZK[2024]087GCC[2023]060)。
文摘The Martian core mainly contains iron,nickel and some light elements.However,controversies remain about the structure and chemical composition of the Martian core due to a lack of samples and marsquake data.Recently,the InSight lander collected long-term marsquake data,which improved the Martian interior structure model.B ased on the preliminary analysis of marsquake data,Mars has a molten liquid core with a radius of around 1700 km.As the Martian core has a smaller density and lower temperature than pure iron at corresponding pressure and temperature conditions,some light elements are introduced to reduce the density and liquidus temperature.With various methods for seismic analysis,in-situ high-pressure and high-temperature experiments,and first-principal calculations,the Martian core composition and evolution models have been updated in the past few years.Here,we review those studies on the light elements in the Martian core from four aspects including(1)high-temperature and high-pressure experiments,(2)marsquake data,(3)mineral physics model with molecular dynamics simulations and(4)cosmochemistry investigation.We discussed the effect of different light elements on the Martian core s density,sound velocity and liquidus temperature.Moreover,the review examines the varieties,abundances and forms of light elements in the Martian core.
文摘Against the backdrop of profound restructuring in the global industrial and supply chains,data elements have emerged as a critical force driving the transformation of enterprises'new quality productive forces.To address the ambiguity surrounding its micro-level empowerment mechanism,this paper empirically examines the impact of data elements on enterprises'new quality productive forces and its transmission channels using panel data of Chinese A-share listed firms from 2014 to 2023.The results show that data elements significantly improve the level of enterprises'new quality productive forces.Heterogeneity analysis indicates that this promotional effect is more pronounced in non-state-owned enterprises,large-scale enterprises,and low-leverage enterprises.Mechanism tests confirm that data elements empower new quality productive forces through three paths:enhancing enterprise innovation capability,improving internal operational efficiency,and promoting inter-firm collaboration efficiency.This study provides empirical evidence for understanding the micro-level empowerment logic of data elements and offers theoretical references and practical implications for advancing the deep integration of the digital economy and the real economy.
基金financial support from the National Key Research and Development Project of China(No.2019YFA0705300)the National Natural Science Foundation of China(No.52004051)+1 种基金the Project of Zhongyuan Critical Metals Laboratory,China(No.GJJSGFYQ202321)the Fund for Priority Support of Research Projects by Returned Overseas Scholars in Henan Province,China。
文摘The influence of varying levels of impurity elements on the hot corrosion resistance of the DD98M alloy in Na_(2)SO_(4)+NaCl salt at 950℃ was investigated.The results indicate that the corrosion resistance of the DD98M alloy significantly decreases with an increase in impurity content,and the presence of nitrogen leads to an increase in alloy porosity.These porosities promote the rapid diffusion of molten salt and oxygen into the alloy,resulting in a bilateral diffusion of oxygen and sulfur,which leads to an accumulation of these elements at the oxide−matrix interface.This process contributes to the formation and propagation of interfacial cracks.A growth model was developed for hot corrosion products in alloys with varying impurity elements.
基金supported by the Tianjin Education Commission Research Program Project(No.2024KJ105)。
文摘The buoyancy-induced flow constitutes a core scientific issue for thermal management of electronic devices and thermal design of energy systems,where accurate characterization of flow and heat transfer is essential to improve thermal efficiency.In this work,buoyancy-induced flow above two heating elements flush-mounted at the bottom of a square enclosure containing air is numerically investigated over a range of Rayleigh numbers(0<Ra≤1.5×10^(8)),with a focus on equal and unequal heat flux conditions under a constraint of constant total thermal energy input.Distinct flow transitions are observed in both cases,leading to the identification of three flow regimes:Steady,periodic unsteady,and chaotic unsteady.Two types of periodic flows are distinguished,in which the first is a periodic flow dominated by a fundamental frequency(FF)and its integer-multiple frequencies(INTMF),while the second is a more complex periodic flow featuring FF,INTMF,and their sub-harmonics.The transitions between these regimes are affected by the relative heat flux of the two heaters.When the heat flux of the two heaters is unequal,the range of Rayleigh numbers corresponding to periodic flow is suppressed.It is also found that the time-averaged maximum temperature of the strong heater increases more rapidly with Ra,while that of the weak heater increases more slowly,reflecting the interaction between buoyancy-driven flow dynamics and asymmetric heat input.Analysis of the time-averaged Nusselt number demonstrates that heat dissipation from the isothermal walls remains roughly equivalent,even when the heat flux of the two heaters differs by a factor of two.These findings highlight the critical roles of Rayleigh number,the number of heaters,and the heat flux ratio of the heaters in determining heat transfer and flow characteristics for buoyancy-driven convection systems,providing important theoretical support and design references for engineering scenarios such as electronic devices and design of new energy systems.
基金supported by National Science and Technology Major Project(2025ZD0618901)National Natural Science Foundation of China(U2241245 and 52321001)+2 种基金Aeronautical Science Foundation of China(2022Z053092001)Natural Science Foundation of Shenyang(23-503-6-05)Science and Technology Major Project of Liaoning Province(2024JH1/11700028).
文摘Effects of alloying elements Ni,Co,Mn,Cr,and H on the stacking fault energy(SFE)ofγ-Fe and its microscopic mechanisms were systematically investigated.Generalized SFE calculations show that individual alloying elements Ni,Co,and H increase SFE ofγ-Fe,whereas Mn and Cr decrease SFE.The influence of alloying elements on SFE exhibits short-range characteristics.The effect of synergistic interaction of alloying elements and H on SFE was further investigated.Results show that the co-alloying of Ni/Co with H exacerbates the effect of H on the increase in SFE.In contrast,the synergistic effect of Mn/Cr with H tends to inhibit H from the increasing SFE.Finally,the electronic structure analysis elucidated the microscopic mechanism of the change in SFE.Alloying elements modulate SFE by changing the interatomic charge density at the stacking fault plane and the density of states of the stacking fault structure at the Fermi level.The present results add to the knowledge of alloying related influence on the mechanical property and hydrogen embrittlement ofγ-Fe.
文摘On the stone-paved lanes of Songyang County that date back to ancient times,morning mist lingered as a faint fragrance of tea wafted from a century-old house.Inside,Yang Junjie,a tea maker born in the 1980s,worked deftly at the stove,his hands moving swiftly over the scorching iron wok as tender green tea leaves dance between his fingers.
文摘Fig.3.(a)α-particle energy spectra,and(b)decay-time distributions on a logarithmic scale for the observed 288Mc and its descendant nuclei.In the panel(a),the red histograms show the observed full-energy events,while the corresponding blue histograms show the reconstructed events.The red smooth curves in panel(b)are the expected time distributions according to the corresponding half-lives extracted from this work.
基金supported in part by the National Key R&D Program of China (Contract Nos.2023YFA1606500,2024YFE0109800,and 2024YFE0110400)Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB34010000)+5 种基金the Gansu Key Project of Science and Technology (Grant No.23ZDGA014)the Guangdong Major Project of Basic and Applied Basic Research (Grant No.2021B0301030006)the National Natural Science Foundation of China (Grant Nos.12105328,W2412040,12475126,12422507,12035011,12375118,12435008,and W2412043)the Chinese Academy of Sciences Project for Young Scientists in Basic Research(Grant No.YSBR-002)the Youth Innovation Promotion Association of the Chinese Academy of Sciences (Grant Nos.2020409 and 2023439)the Russian Science Foundation (Grant No.25-42-00003)。
文摘We report the results of the experiment on synthesizing ^(287,288)Mc isotopes (Z=115) using the fusionevaporation reaction ^(243)Am(^(48)Ca,4n,3n)^(287,288)Mc at the Spectrometer for Heavy Atoms and Nuclear Structure-2(SHANS2),a gas-filled recoil separator located at the China Accelerator Facility for Superheavy Elements(CAFE2).In total,20 decay chains are attributed to ^(288)Mc and 1 decay chain is assigned to ^(287)Mc.The measured oa-decay properties of ^(287,288)Mc as well as its descendants are consistent with the known data.No additional decay chains originating from the 2n or 5n reaction channels were detected.The excitation function of the ^(243)Am(^(48)Ca,3n)^(288)Mc reaction was measured at the cross-section level of picobarn,which indicates the promising capability for the study of heavy and superheavy nuclei at the facility.
基金supported by the National Natural Science Foundation of China, No.61932008Natural Science Foundation of Shanghai, No.21ZR1403200 (both to JC)。
文摘Neurodegenerative diseases cause great medical and economic burdens for both patients and society;however, the complex molecular mechanisms thereof are not yet well understood. With the development of high-coverage sequencing technology, researchers have started to notice that genomic repeat regions, previously neglected in search of disease culprits, are active contributors to multiple neurodegenerative diseases. In this review, we describe the association between repeat element variants and multiple degenerative diseases through genome-wide association studies and targeted sequencing. We discuss the identification of disease-relevant repeat element variants, further powered by the advancement of long-read sequencing technologies and their related tools, and summarize recent findings in the molecular mechanisms of repeat element variants in brain degeneration, such as those causing transcriptional silencing or RNA-mediated gain of toxic function. Furthermore, we describe how in silico predictions using innovative computational models, such as deep learning language models, could enhance and accelerate our understanding of the functional impact of repeat element variants. Finally, we discuss future directions to advance current findings for a better understanding of neurodegenerative diseases and the clinical applications of genomic repeat elements.
基金Artificial Intelligence Education Research Project of Shandong Provincial Audio-Visual Education Center“Exploration of the Application of Large-scale AI Models in Student Value-added Evaluation from an Evidence-based Perspective”(SDDJ202501035)。
文摘Value-added evaluation focuses on individual student growth by tracking changes in academic performance,skills,literacy,etc.,at different time points.It weakens horizontal comparisons and emphasizes vertical progress to more fairly reflect educational effectiveness.This evaluation method is particularly suitable for vocational education,effectively motivating students’learning enthusiasm and enhancing their self-confidence.Foreign research is represented by the Tennessee Value-Added Assessment System(TVAAS),widely used in evaluating school quality and teacher performance.Domestic research currently focuses on the theoretical construction,model establishment,optimization,and practical application of value-added evaluation,still facing significant challenges in data collection comprehensiveness and model adaptability.Aiming at current issues,this study focuses on exploring the application of artificial intelligence large models in student value-added evaluation from an evidence-based perspective,committed to constructing an innovative evidence-based value-added evaluation system.It aims to achieve precise assessment of students’learning effect“net value-added”through multi-source data collection,intelligent analysis,and personalized feedback.The system integrates outcome evaluation,process evaluation,value-added evaluation,and comprehensive evaluation to form a“four-in-one”dynamic evaluation framework,considering students’starting points,process performance,and final achievements.In the future,value-added evaluation needs to further expand the assessment of non-academic dimensions(such as professional literacy and social-emotional skills)and explore the application of non-linear models to promote the deepening and innovation of educational evaluation reform.
基金financially supported by the National Natural Science Foundation of China(Nos.52293395 and 52293393)the Xiongan Science and Technology Innovation Talent Project of MOST,China(No.2022XACX0500).
文摘Producing steel requires large amounts of energy to convert iron ores into steel,which often comes from fossil fuels,leading to carbon emissions and other pollutants.Increasing scrap usage emerges as one of the most effective strategies for addressing these issues.However,typical residual elements(Cu,As,Sn,Sb,Bi,etc.)inherited from scrap could significantly influence the mechanical properties of steel.In this work,we investigate the effects of residual elements on the microstructure evolution and mechanical properties of a quenching and partitioning(Q&P)steel by comparing a commercial QP1180 steel(referred to as QP)to the one containing typical residual elements(Cu+As+Sn+Sb+Bi<0.3wt%)(referred to as QP-R).The results demonstrate that in comparison with the QP steel,the residual elements significantly refine the prior austenite grain(9.7μm vs.14.6μm)due to their strong solute drag effect,leading to a higher volume fraction(13.0%vs.11.8%),a smaller size(473 nm vs.790 nm)and a higher average carbon content(1.26 wt%vs.0.99 wt%)of retained austenite in the QP-R steel.As a result,the QP-R steel exhibits a sustained transformation-induced plasticity(TRIP)effect,leading to an enhanced strain hardening effect and a simultaneous improvement of strength and ductility.Grain boundary segregation of residual elements was not observed at prior austenite grain boundaries in the QP-R steel,primarily due to continuous interface migration during austenitization.This study demonstrates that the residual elements with concentrations comparable to that in scrap result in significant microstructural refinement,causing retained austenite with relatively higher stability and thus offering promising mechanical properties and potential applications.
基金This paper is the research result of“Research on Innovation of Evidence-Based Teaching Paradigm in Vocational Education under the Background of New Quality Productivity”(2024JXQ176)the Shandong Province Artificial Intelligence Education Research Project(SDDJ202501035),which explores the application of artificial intelligence big models in student value-added evaluation from an evidence-based perspective。
文摘Based on the educational evaluation reform,this study explores the construction of an evidence-based value-added evaluation system based on data-driven,aiming to solve the limitations of traditional evaluation methods.The research adopts the method of combining theoretical analysis and practical application,and designs the evidence-based value-added evaluation framework,which includes the core elements of a multi-source heterogeneous data acquisition and processing system,a value-added evaluation agent based on a large model,and an evaluation implementation and application mechanism.Through empirical research verification,the evaluation system has remarkable effects in improving learning participation,promoting ability development,and supporting teaching decision-making,and provides a theoretical reference and practical path for educational evaluation reform in the new era.The research shows that the evidence-based value-added evaluation system based on data-driven can reflect students’actual progress more fairly and objectively by accurately measuring the difference in starting point and development range of students,and provide strong support for the realization of high-quality education development.
基金supports from the National Key Research and Development Program of China(2023YFB2806803)the National Natural Science Foundation of China(62075127).
文摘Liquid crystal Pacharatnam-Berry phase optical elements(PBOEs)have found promising applications in augmented reality and virtual reality because of their slim formfactor,lightweight,and high optical efficiency.However,chromatic aberration remains a serious longstanding problem for diffractive optics,hindering their broader adoption.To overcome the chromatic aberrations for red,green and blue(RGB)light sources,in this paper,we propose a counterintuitive multi-twist structure to achieve narrowband PBOEs without crosstalk,which plays a vital role to eliminate the chromatic aberration.The performance of our designed and fabricated narrowband Pacharatnam-Berry lenses(PBLs)aligns well with our simulation results.Furthermore,in a feasibility demonstration experiment using a laser projector,our proposed PBL system indeed exhibits a diminished chromatic aberration as compared to a broadband PBL.Additionally,polarization raytracing is implemented to demonstrate the versatility of the multi-twist structure for designing any RGB wavelengths with high contrast ratios.This analysis explores the feasibility of using RGB laser lines and quantum dot light-emitting diodes.Overall,our approach enables high optical efficiency,low fabrication complexity,and high degree of design freedom to accommodate any liquid crystal material and RGB light sources,holding immense potential for widespread applications of achromatic PBOEs.
文摘The data production elements are driving profound transformations in the real economy across production objects,methods,and tools,generating significant economic effects such as industrial structure upgrading.This paper aims to reveal the impact mechanism of the data elements on the“three transformations”(high-end,intelligent,and green)in the manufacturing sector,theoretically elucidating the intrinsic mechanisms by which the data elements influence these transformations.The study finds that the data elements significantly enhance the high-end,intelligent,and green levels of China's manufacturing industry.In terms of the pathways of impact,the data elements primarily influence the development of high-tech industries and overall green technological innovation,thereby affecting the high-end,intelligent,and green transformation of the industry.
文摘Rare earth elements(REEs),with their unique magnetic,optical,and electrical properties,have become indispensable strategic resources.Widely applied in critical fields such as aviation,telecommunications,electronics,energy,transportation,and medicine,REEs play a vital role in advancing technology and driving social and economic development.However,the REE industry faces numerous challenges,including unbalanced resource distribution,supply and demand imbalances,international competition,technological limitations,and associated environmental pollution.This paper,incorporating both the historical evolution and current state of the REE industry,provides a comprehensive examination of the chemistry,applications,resources,technologies,challenges,and prospects of REEs.Specifically,it analyzes China's REE industry,which holds the largest global reserves and production capacity.As a key feature,this paper introduces the Tai Chi model for sustainable development in the REE industry,offering an in-depth analysis of two primary approaches—mining and recycling;the four critical participants—governments,enterprises,researchers,and consumers;and the eight essential influencing factors—resources,energy,environment,policy,applications,technology,supply and demand,and economy.The Tai Chi model not only clarifies the responsibilities and significance of each individual but also highlights their interconnectedness,providing a compelling framework for envisioning the sustainable development of the REE industry.Moreover,the paper identifies the major challenges currently facing the industry and offers insights into the future development of REEs.As such,this work contributes to a deeper understanding of the multifaceted REE landscape and underscores the importance of sustainable practices to ensure REEs'lasting positive impact on the global industry.
基金supported by National Natural Science Foundation of China(Grants 72474022,71974011,72174022,71972012,71874009)"BIT think tank"Promotion Plan of Science and Technology Innovation Program of Beijing Institute of Technology(Grants 2024CX14017,2023CX13029).
文摘As a new type of production factor in healthcare,healthcare data elements have been rapidly integrated into various health production processes,such as clinical assistance,health management,biological testing,and operation and supervision[1,2].Healthcare data elements include biolog.ical and clinical data that are related to disease,environ-mental health data that are associated with life,and operational and healthcare management data that are related to healthcare activities(Figure 1).Activities such as the construction of a data value assessment system,the devel-opment of a data circulation and sharing platform,and the authorization of data compliance and operation products support the strong growth momentum of the market for health care data elements in China[3].
