In recent years,the use of deep learning to replace traditional numerical methods for electromagnetic propagation has shown tremendous potential in the rapid design of photonic devices.However,most research on deep le...In recent years,the use of deep learning to replace traditional numerical methods for electromagnetic propagation has shown tremendous potential in the rapid design of photonic devices.However,most research on deep learning has focused on single-layer grating couplers,and the accuracy of multi-layer grating couplers has not yet reached a high level.This paper proposes and demonstrates a novel deep learning network-assisted strategy for inverse design.The network model is based on a multi-layer perceptron(MLP)and incorporates convolutional neural networks(CNNs)and transformers.Through the stacking of multiple layers,it achieves a high-precision design for both multi-layer and single-layer raster couplers with various functionalities.The deep learning network exhibits exceptionally high predictive accuracy,with an average absolute error across the full wavelength range of 1300–1700 nm being only 0.17%,and an even lower predictive absolute error below 0.09%at the specific wavelength of 1550 nm.By combining the deep learning network with the genetic algorithm,we can efficiently design grating couplers that perform different functions.Simulation results indicate that the designed single-wavelength grating couplers achieve coupling efficiencies exceeding 80%at central wavelengths of 1550 nm and 1310 nm.The performance of designed dual-wavelength and broadband grating couplers also reaches high industry standards.Furthermore,the network structure and inverse design method are highly scalable and can be applied not only to multi-layer grating couplers but also directly to the prediction and design of single-layer grating couplers,providing a new perspective for the innovative development of photonic devices.展开更多
With digital coding technology,reconfigurable intelligent surfaces(RISs)become powerful real-time sys-tems for manipulating electromagnetic(EM)waves.However,most automatic RIS designs involve exten-sive numerical simu...With digital coding technology,reconfigurable intelligent surfaces(RISs)become powerful real-time sys-tems for manipulating electromagnetic(EM)waves.However,most automatic RIS designs involve exten-sive numerical simulations of the unit,including the passive pattern and active devices,requiring high data acquisition and training costs.In addition,for passive patterns,the widely employed random pixe-lated method presents design efficiency and effectiveness challenges due to the massive pixel combina-tions and blocked excitation current flow in discrete patterns.To overcome these two critical problems,we propose a versatile RIS design paradigm with efficient topology representation and a separate design architecture.First,a non-uniform rational B-spline(NURBS)is introduced to represent continuous pat-terns and solve excitation current flow issues.This representation makes it possible to finely tune con-tinuous patterns with several control points,greatly reducing the pattern solution space by 20-fold and facilitating RIS optimization.Then,employing multiport network theory to separate the passive pat-tern and active device from the unit,the separate design architecture significantly reduces the dataset acquisition cost by 62.5%.Through multistep multiport calculation,the multistate EM responses of the RIS under different structural combinations can be quickly obtained with only one prediction of pattern response,thereby achieving dataset and model reuse for different RIS designs.With a hybrid continuous-discrete optimization algorithm,three examples—including two typical high-performance RISs and an ultra-wideband multilayer RIS—are provided to validate the superiority of our paradigm.Our work offers an efficient solution for RIS automatic design,and the resulting structure is expected to boost RIS appli-cations in the fields of wireless communication and sensing.展开更多
Materials that are difficult to cut,such as titanium alloys,are widely used in large load-bearing integral components of aircraft,leading to great challenges for manufacturing.Electrochemical milling is a way for mach...Materials that are difficult to cut,such as titanium alloys,are widely used in large load-bearing integral components of aircraft,leading to great challenges for manufacturing.Electrochemical milling is a way for machining difficult-to-cut materials through Computer Numerical Control(CNC)trajectory motion.Using a tilted large cathode machining surface and the cut-in feed mode,an efficient and low-cost method is obtained for machining the large integral components.A novel crossed and inclined structure of the flow mode is designed to realize electrochemical milling with a large tilted cathode surface.Compared to the vertical flow mode with one inlet,the proposed flow mode has two inlets that independently supply electrolytes,and the inclined channels make the flow field more stable.Flow field simulations are performed for both the vertical and proposed flow modes.The results show that the proposed flow mode avoids the random diversion of electrolytes and the ultralow flow velocity at both ends of the nozzle area,improving the velocity,uniformity,and stability of the electrolytes.The inclination angle of the crossed and inclined flow field is optimized.Finally,limit feed rate experiments are conducted in two modes,and the limit feed rate is 70 mm/min in the proposed mode.A sector workpiece of a large circular surface with approximately 8.77 mm thickness is machined 9 times by the cut-in electrochemical milling,the material removal rate is 4872 mm^(3)/min,and the surface roughness is superior to 1.15μm.展开更多
Light-to-thermal conversion materials(LTCMs)have been of great interest to researchers due to their impressive energy conversion capacity and wide range of applications in biomedical,desalination,and synergistic catal...Light-to-thermal conversion materials(LTCMs)have been of great interest to researchers due to their impressive energy conversion capacity and wide range of applications in biomedical,desalination,and synergistic catalysis.Given the limited advances in existing materials(metals,semiconductors,π-conjugates),researchers generally adopt the method of constructing complex systems and hybrid structures to optimize performance and achieve multifunctional integration.However,the development of LTCMs is still in its infancy as the physical mechanism of light-to-thermal conversion is unclear.In this review,we proposed design strategies for efficient LTCMs by analyzing the physical process of light-tothermal conversion.First,we analyze the nature of light absorption and heat generation to reveal the physical processes of light-to-thermal conversion.Then,we explain the light-to-thermal conversion mechanisms of metallic,semiconducting andπ-conjugated LCTMs,and propose new material design strategies and performance improvement methods.Finally,we summarize the challenges and prospects of LTCMs in emerging applications such as solar water evaporation and photothermal catalysis.展开更多
Graphene,owing to its exceptional electronic,optical,thermal,and mechanical properties,has emerged as a highly promising material.Currently,the synthesis of large-area graphene films on metal substrates via chemical v...Graphene,owing to its exceptional electronic,optical,thermal,and mechanical properties,has emerged as a highly promising material.Currently,the synthesis of large-area graphene films on metal substrates via chemical vapor deposition remains the predominant approach for producing high-quality graphene.To realize the potential applications of graphene,it is essential to transfer graphene films to target substrates in a manner that is non-destructive,clean,and efficient,as this significantly affects the performance of graphene devices.This review examines the current methods for graphene transfer from three perspectives:non-destructive transfer,clean transfer,and high-efficiency transfer.It analyzes and compares the advancements and limitations of various transfer techniques.Finally,the review identifies the key challenges faced by current graphene transfer methods and anticipates future developmental prospects.展开更多
Through literature analysis and case study, the introduction history, variety selection (high bush, half high bush, low bush) and regional cultivation techniques of blueberry in China were summarized, and the practica...Through literature analysis and case study, the introduction history, variety selection (high bush, half high bush, low bush) and regional cultivation techniques of blueberry in China were summarized, and the practical effects of precision cultivation (water and fertilizer integration, wild planting) and under-forest economic model (forest-blueberry-fungus system, ecological tourism) were evaluated. It provided a technical reference for expanding the planting scale of blueberry and improving the fruit quality.展开更多
The addition of cold flow improvers(CFIs)is considered as the optimum strategy to improve the cold flow properties(CFPs)of diesel fuels,but this strategy is always limited by the required large dosage.To obtain low-do...The addition of cold flow improvers(CFIs)is considered as the optimum strategy to improve the cold flow properties(CFPs)of diesel fuels,but this strategy is always limited by the required large dosage.To obtain low-dosage and high-efficiency CFIs for diesel,1,2,3,6-tetrahydrophthalic anhydride(THPA)was introduced as a third and polar monomer to enhance the depressive effects of alkyl methacrylatetrans anethole copolymers(C_(14)MC-TA).The terpolymers of alkyl methacrylate-trans anethole-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-TA-THPA)were synthesized and compared with the binary copolymers of C_(14)MC-TA and alkyl methacrylate-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-THPA).Results showed that C_(14)MC-THPA achieved the best depressive effects on the cold filter plugging point(CFPP)and solid point(SP)by 11℃and 16℃at a dosage of 1250 mg/L and monomer ratio of 6:1,while 1500mg/L C_(14)MC-TA(1:1)reached the optimal depressive effects on the CFPP and SP by 12℃and 18℃.THPA introduction significantly improved the depressive effects of C_(14)MC-TA.Lower dosages of C_(14)MCTA-THPA in diesel exerted better improvement effects on the CFPP and SP than that of C_(14)MC-TA and C_(14)MC-THPA.When the monomer ratio and dosage were 6:0.6:0.4 and 1000 mg/L,the improvement effect of C_(14)MC-TA-THPA on diesel reached the optimum level,and the CFPP and SP were reduced by 13℃and 19℃,respectively.A 3D nonlinear surface diagram fitted by a mathematical model was also used for the first time to better understand the relationships of monomer ratios,dosages,and depressive effects of CFIs in diesel.Surface analysis results showed that C_(14)MC-TA-THPA achieved the optimum depressive effects at a monomer ratio of 6:0.66:0.34 and dosage of 1000 mg/L,and the CFPP and SP decreased by 14℃ and 19℃,respectively.The predicted results were consistent with the actual ones.Additionally,the improvement mechanism of these copolymers in diesel was also explored.展开更多
In this study,an inverse design framework was established to find lightweight honeycomb structures(HCSs)with high impact resistance.The hybrid HCS,composed of re-entrant(RE)and elliptical annular re-entrant(EARE)honey...In this study,an inverse design framework was established to find lightweight honeycomb structures(HCSs)with high impact resistance.The hybrid HCS,composed of re-entrant(RE)and elliptical annular re-entrant(EARE)honeycomb cells,was created by constructing arrangement matrices to achieve structural lightweight.The machine learning(ML)framework consisted of a neural network(NN)forward regression model for predicting impact resistance and a multi-objective optimization algorithm for generating high-performance designs.The surrogate of the local design space was initially realized by establishing the NN in the small sample dataset,and the active learning strategy was used to continuously extended the local optimal design until the model converged in the global space.The results indicated that the active learning strategy significantly improved the inference capability of the NN model in unknown design domains.By guiding the iteration direction of the optimization algorithm,lightweight designs with high impact resistance were identified.The energy absorption capacity of the optimal design reached 94.98%of the EARE honeycomb,while the initial peak stress and mass decreased by 28.85%and 19.91%,respectively.Furthermore,Shapley Additive Explanations(SHAP)for global explanation of the NN indicated a strong correlation between the arrangement mode of HCS and its impact resistance.By reducing the stiffness of the cells at the top boundary of the structure,the initial impact damage sustained by the structure can be significantly improved.Overall,this study proposed a general lightweight design method for array structures under impact loads,which is beneficial for the widespread application of honeycomb-based protective structures.展开更多
Purpose-Interface management is the process of managing communications,responsibilities and coordination of project parties,phases or physical entities which are dependent on one another.Interface management is a cruc...Purpose-Interface management is the process of managing communications,responsibilities and coordination of project parties,phases or physical entities which are dependent on one another.Interface management is a crucial part of managing any construction project-but particularly important for high-speed railway projects that often have several contractual parties and stakeholders,very long project timelines and huge upfront cost overlays.This paper discusses how various project interfaces were managed during the design and construction of the civil engineering infrastructure for the High Speed Two(HS2)project in the United Kingdom.Design/methodology/approach-The paper uses the case study methodology.Key interfaces on the HS2 project are grouped into various categories and the paper discusses how they were managed within the Area North Integrated Project Team(IPT)of the HS2 project made up of contractor Balfour Beatty VINCI(BBV),the Mott MacDonald SYSTRA Design Joint Venture(DJV)and client HS2 Ltd.3 different case studies drawn from across the IPT are used,each of them highlighting different interfaces and how these interfaces were managed.Findings-The paper shows how innovative technical designs and modern methods of construction were used to address some of the unique and peculiar challenges of designing a brand-new railway in the United Kingdom.Addressing the contrasting and often competing requirements of different stakeholders,coupled with challenging physical constraints of the very limited land available for the project and the use of a rarely used Act of Parliament in the delivery of the project required different approach to interface management.Collaboration and proactive stakeholder engagement are necessary for successful interface management on megaprojects.The authors posit that adopting an integrated approach to engineering and construction management is an essential ingredient for the successful delivery of high-speed railway projects.Originality/value-With many high-speed railway projects around the world coming up in the next few years,understanding the context and challenges for each country will help engineering and design managers adopt appropriate approaches for their projects.The lessons learned on the HS2 project are also transferable to other mega infrastructure projects with complex project interfaces.展开更多
Against the backdrop of escalating global climate change and energy crises,the resource utilization of carbon dioxide(CO_(2)),a major greenhouse gas,has become a crucial pathway for achieving carbon peaking and carbon...Against the backdrop of escalating global climate change and energy crises,the resource utilization of carbon dioxide(CO_(2)),a major greenhouse gas,has become a crucial pathway for achieving carbon peaking and carbon neutrality goals.The hydrogenation of CO_(2)to methanol not only enables carbon sequestration and recycling,but also provides a route to produce high value-added fuels and basic chemical feedstocks,holding significant environmental and economic potential.However,this conversion process is thermodynamically and kinetically limited,and traditional catalyst systems(e.g.,Cu/ZnO/Al_(2)O_(3))exhibit inadequate activity,selectivity,and stability under mild conditions.Therefore,the development of novel high-performance catalysts with precisely tunable structures and functionalities is imperative.Metal-organic frameworks(MOFs),as crystalline porous materials with high surface area,tunable pore structures,and diverse metal-ligand compositions,have the great potential in CO_(2)hydrogenation catalysis.Their structural design flexibility allows for the construction of well-dispersed active sites,tailored electronic environments,and enhanced metal-support interactions.This review systematically summarizes the recent advances in MOF-based and MOF-derived catalysts for CO_(2)hydrogenation to methanol,focusing on four design strategies:(1)spatial confinement and in situ construction,(2)defect engineering and ion-exchange,(3)bimetallic synergy and hybrid structure design,and(4)MOF-derived nanomaterial synthesis.These approaches significantly improve CO_(2)conversion and methanol selectivity by optimizing metal dispersion,interfacial structures,and reaction pathways.The reaction mechanism is further explored by focusing on the three main reaction pathways:the formate pathway(HCOO*),the RWGS(Reverse Water Gas Shift reaction)+CO*hydrogenation pathway,and the trans-COOH pathway.In situ spectroscopic studies and density functional theory(DFT)calculations elucidate the formation and transformation of key intermediates,as well as the roles of active sites,metal-support interfaces,oxygen vacancies,and promoters.Additionally,representative catalytic performance data for MOFbased systems are compiled and compared,demonstrating their advantages over traditional catalysts in terms of CO_(2)conversion,methanol selectivity,and space-time yield.Future perspectives for MOF-based CO_(2)hydrogenation catalysts will prioritize two main directions:structural design and mechanistic understanding.The precise construction of active sites through multi-metallic synergy,defect engineering,and interfacial electronic modulation should be made to enhance catalyst selectivity and stability.In addition,advanced in situ characterization techniques combined with theoretical modeling are essential to unravel the detailed reaction mechanisms and intermediate behaviors,thereby guiding rational catalyst design.Moreover,to enable industrial application,challenges related to thermal/hydrothermal stability,catalyst recyclability,and cost-effective large-scale synthesis must be addressed.The development of green,scalable preparation methods and the integration of MOF catalysts into practical reaction systems(e.g.,flow reactors)will be crucial for bridging the gap between laboratory research and commercial deployment.Ultimately,multi-scale structure-performance optimization and catalytic system integration will be vital for accelerating the industrialization of MOF-based CO_(2)-to-methanol technologies.展开更多
The electrochemical oxidation of biomass-derived platform molecule 5-hydroxymethylfurfural(HMF)represents a crucial pathway for green transformation into high-value chemicals,yet its reaction pathway selectivity,effic...The electrochemical oxidation of biomass-derived platform molecule 5-hydroxymethylfurfural(HMF)represents a crucial pathway for green transformation into high-value chemicals,yet its reaction pathway selectivity,efficiency,and catalyst stability are strongly dependent on the electrolyte pH environment.Under alkaline conditions,high OH−concentration facilitates preferential aldehyde group oxidation and efficient deprotonation,enabling highly efficient synthesis of 2,5-furandicarboxylic acid,but simultaneously induces HMF self-degradation and complicates product separation.As pH decreases,the reaction mechanism shifts toward enhanced hydroxymethyl oxidation,leading to intermediate accumulation(such as 5-hydroxymethyl-2-furancarboxylic acid,2,5-diformylfuran,and 5-formyl-2-furancarboxylic acid)with challenging selectivity control and significantly slowed reaction kinetics.This review comprehensively examines the systematic differences in HMF oxidation pathways and surface catalytic mechanisms across the full pH range from alkaline to acidic conditions.Addressing the distinct reaction characteristics and core challenges in alkaline,near-neutral,and acidic media,we systematically evaluate design strategies for high-efficiency electrocatalysts and explore reactor design aspects.Future research should focus on process integration(with tailored reactor design)for energy consumption reduction in alkaline systems,targeted synthesis of diverse oxidation products in near-neutral systems,and innovative catalyst development for acidic systems,thereby advancing the efficiency,selectivity,and practical application of HMF electrooxidation technologies across the entire pH spectrum through synergistic optimization of catalyst,reactor,and process.展开更多
In mixture experiments,the observed response is determined by the relative proportions of the components,consequently rendering the experimental region a simplex.This paper focuses primarily on the optimal designs of ...In mixture experiments,the observed response is determined by the relative proportions of the components,consequently rendering the experimental region a simplex.This paper focuses primarily on the optimal designs of mixture experiments that involve process variables.Prior research has extensively delved into optimal orthogonal block designs for some classic mixture models with process variables.Based on the framework of general blending models,this paper proposes a class of symmetric linear mixture models,which can be regarded as a generalization of many existing ones.Under the orthogonal blocking conditions,orthogonal block designs are devised through Latin squares in the presence of process variables.TheD-,A-,and E-optimality criteria are utilized to obtain optimal designs at the boundary of the simplex in the case of 3 components.As the values of the exponents change,numerically derived optimal design points are presented to illustrate the pattern of their variations,and to verify the consistency of the results with previous research on some specific symmetric general blending models.展开更多
In this paper,we provide a comprehensive examination of the evolution of graphics Application Programming Interfaces(APIs).We begin by exploring traditional graphics APIs,elucidating their distinct features and inhere...In this paper,we provide a comprehensive examination of the evolution of graphics Application Programming Interfaces(APIs).We begin by exploring traditional graphics APIs,elucidating their distinct features and inherent challenges.This sets the stage for a detailed exploration of modern graphics APIs,with a focus on four critical design principles.These principles are further analyzed through specific case studies and categorical examinations.The paper then introduces MoerEngine,a bespoke rendering engine,as a practical case to demonstrate the real-world application of these modern principles in software engineering.In conclusion,the study offers insights into the potential future trajectory of graphics APIs,spotlighting emerging design patterns and technological innovations.It also ventures to predict the development trends and capabilities of next-generation graphics APIs.展开更多
Memristors have emerged as a transformative technology in the realm of electronic devices,offering unique advantages such as fast switching speeds,low power consumption,and the ability to sensor-memory-compute.The app...Memristors have emerged as a transformative technology in the realm of electronic devices,offering unique advantages such as fast switching speeds,low power consumption,and the ability to sensor-memory-compute.The applications span across non-volatile memory,neuromorphic computing,hardware security,and beyond,prompting memristors to become a versatile solution for next-generation computing and data storage systems.Despite enormous potential of memristors,the transition from laboratory prototypes to large-scale applications is challenging in terms of material stability,device reproducibility,and array scalability.This review systematically explores recent advancements in high-performance memristor technologies,focusing on performance enhancement strategies through material engineering,structural design,pulse protocol optimization,and algorithm control.We provide an in-depth analysis of key performance metrics tailored to specific applications,including non-volatile memory,neuromorphic computing,and hardware security.Furthermore,we propose a co-design framework that integrates device-level optimizations with operational-level improvements,aiming to bridge the gap between theoretical models and practical implementations.展开更多
Compact size,high brightness,and wide field of view(FOV)are key requirements for long-wave infrared imagers used in military surveillance or night navigation.However,to meet the imaging requirements of high resolution...Compact size,high brightness,and wide field of view(FOV)are key requirements for long-wave infrared imagers used in military surveillance or night navigation.However,to meet the imaging requirements of high resolution and wide FOV,infrared optical systems often adopt complex optical lens groups,which will increase the size and weight of the optical system.In this paper,a strategy based on wavefront coding(WFC)is proposed to design a compact wide-FOV infrared imager.A cubic phase mask is inserted into the pupil plane of the infrared imager to correct the aberration.The simulated results show that,the WFC infrared imager has good imaging quality in a wide FOV of±16°.In addition,the WFC infrared imager achieves compactness with its 40 mm×40 mm×40 mm size.A fast focal ratio of 1 combined with an entrance pupil diameter of 25 mm ensures brightness.This work is of significance for designing a compact wide-FOV infrared imager.展开更多
Both large-scale prospective randomized controlled trials(RCTs)and smaller investigator-initiated trials are essential for evaluating the efficacy and safety of medical interventions.Robust protocols and statistical d...Both large-scale prospective randomized controlled trials(RCTs)and smaller investigator-initiated trials are essential for evaluating the efficacy and safety of medical interventions.Robust protocols and statistical designs ensure the reliability of trial outcomes and improve the credibility of research findings.By reviewing the statistical approaches used in the TORCHLIGHT,NCC2167,and NeoTENNIS trials,this article illustrates the principles underlying large-sample confirmatory RCTs,small-sample exploratory adaptive designs,and single-arm two-stage designs.This discussion is aimed at helping researchers apply these design methods more effectively,to increase the likelihood of success in clinical studies.展开更多
基金sponsored by the National Key Scientific Instrument and Equipment Development Projects of China(Grant No.62027823)the National Natural Science Foun-dation of China(Grant No.61775048).
文摘In recent years,the use of deep learning to replace traditional numerical methods for electromagnetic propagation has shown tremendous potential in the rapid design of photonic devices.However,most research on deep learning has focused on single-layer grating couplers,and the accuracy of multi-layer grating couplers has not yet reached a high level.This paper proposes and demonstrates a novel deep learning network-assisted strategy for inverse design.The network model is based on a multi-layer perceptron(MLP)and incorporates convolutional neural networks(CNNs)and transformers.Through the stacking of multiple layers,it achieves a high-precision design for both multi-layer and single-layer raster couplers with various functionalities.The deep learning network exhibits exceptionally high predictive accuracy,with an average absolute error across the full wavelength range of 1300–1700 nm being only 0.17%,and an even lower predictive absolute error below 0.09%at the specific wavelength of 1550 nm.By combining the deep learning network with the genetic algorithm,we can efficiently design grating couplers that perform different functions.Simulation results indicate that the designed single-wavelength grating couplers achieve coupling efficiencies exceeding 80%at central wavelengths of 1550 nm and 1310 nm.The performance of designed dual-wavelength and broadband grating couplers also reaches high industry standards.Furthermore,the network structure and inverse design method are highly scalable and can be applied not only to multi-layer grating couplers but also directly to the prediction and design of single-layer grating couplers,providing a new perspective for the innovative development of photonic devices.
基金supported by the National Key Research and Development Program of China(2023YFB3811502)the National Science Foundation of China(62225108)+5 种基金the Fundamental Research Funds for the Central Universities(2242022k60003)the National Natural Science Foundation of China(62288101 and 62201139)the Jiangsu Province Frontier Leading Technology Basic Research Project(BK20212002)the Jiangsu Provincial Scientific Research Center of Applied Mathematics(BK20233002)the Fundamental Research Funds for the Central Universities(2242024RCB0005 and 2242024K30009)the 111 Project(111-2-05).
文摘With digital coding technology,reconfigurable intelligent surfaces(RISs)become powerful real-time sys-tems for manipulating electromagnetic(EM)waves.However,most automatic RIS designs involve exten-sive numerical simulations of the unit,including the passive pattern and active devices,requiring high data acquisition and training costs.In addition,for passive patterns,the widely employed random pixe-lated method presents design efficiency and effectiveness challenges due to the massive pixel combina-tions and blocked excitation current flow in discrete patterns.To overcome these two critical problems,we propose a versatile RIS design paradigm with efficient topology representation and a separate design architecture.First,a non-uniform rational B-spline(NURBS)is introduced to represent continuous pat-terns and solve excitation current flow issues.This representation makes it possible to finely tune con-tinuous patterns with several control points,greatly reducing the pattern solution space by 20-fold and facilitating RIS optimization.Then,employing multiport network theory to separate the passive pat-tern and active device from the unit,the separate design architecture significantly reduces the dataset acquisition cost by 62.5%.Through multistep multiport calculation,the multistate EM responses of the RIS under different structural combinations can be quickly obtained with only one prediction of pattern response,thereby achieving dataset and model reuse for different RIS designs.With a hybrid continuous-discrete optimization algorithm,three examples—including two typical high-performance RISs and an ultra-wideband multilayer RIS—are provided to validate the superiority of our paradigm.Our work offers an efficient solution for RIS automatic design,and the resulting structure is expected to boost RIS appli-cations in the fields of wireless communication and sensing.
基金co-supported by National Natural Science Foundation of China(No.52075253)National Natural Science Foundation of China for Creative Research Groups(No.51921003).
文摘Materials that are difficult to cut,such as titanium alloys,are widely used in large load-bearing integral components of aircraft,leading to great challenges for manufacturing.Electrochemical milling is a way for machining difficult-to-cut materials through Computer Numerical Control(CNC)trajectory motion.Using a tilted large cathode machining surface and the cut-in feed mode,an efficient and low-cost method is obtained for machining the large integral components.A novel crossed and inclined structure of the flow mode is designed to realize electrochemical milling with a large tilted cathode surface.Compared to the vertical flow mode with one inlet,the proposed flow mode has two inlets that independently supply electrolytes,and the inclined channels make the flow field more stable.Flow field simulations are performed for both the vertical and proposed flow modes.The results show that the proposed flow mode avoids the random diversion of electrolytes and the ultralow flow velocity at both ends of the nozzle area,improving the velocity,uniformity,and stability of the electrolytes.The inclination angle of the crossed and inclined flow field is optimized.Finally,limit feed rate experiments are conducted in two modes,and the limit feed rate is 70 mm/min in the proposed mode.A sector workpiece of a large circular surface with approximately 8.77 mm thickness is machined 9 times by the cut-in electrochemical milling,the material removal rate is 4872 mm^(3)/min,and the surface roughness is superior to 1.15μm.
基金the financial support from the National Natural Science Foundation of China(Grant Nos.52272153,52032004)the KLOMT Key Laboratory Open Project(2022KLOMT02-05)。
文摘Light-to-thermal conversion materials(LTCMs)have been of great interest to researchers due to their impressive energy conversion capacity and wide range of applications in biomedical,desalination,and synergistic catalysis.Given the limited advances in existing materials(metals,semiconductors,π-conjugates),researchers generally adopt the method of constructing complex systems and hybrid structures to optimize performance and achieve multifunctional integration.However,the development of LTCMs is still in its infancy as the physical mechanism of light-to-thermal conversion is unclear.In this review,we proposed design strategies for efficient LTCMs by analyzing the physical process of light-tothermal conversion.First,we analyze the nature of light absorption and heat generation to reveal the physical processes of light-to-thermal conversion.Then,we explain the light-to-thermal conversion mechanisms of metallic,semiconducting andπ-conjugated LCTMs,and propose new material design strategies and performance improvement methods.Finally,we summarize the challenges and prospects of LTCMs in emerging applications such as solar water evaporation and photothermal catalysis.
基金supported by the National Key R&D Program of China(2020YFB2009002).
文摘Graphene,owing to its exceptional electronic,optical,thermal,and mechanical properties,has emerged as a highly promising material.Currently,the synthesis of large-area graphene films on metal substrates via chemical vapor deposition remains the predominant approach for producing high-quality graphene.To realize the potential applications of graphene,it is essential to transfer graphene films to target substrates in a manner that is non-destructive,clean,and efficient,as this significantly affects the performance of graphene devices.This review examines the current methods for graphene transfer from three perspectives:non-destructive transfer,clean transfer,and high-efficiency transfer.It analyzes and compares the advancements and limitations of various transfer techniques.Finally,the review identifies the key challenges faced by current graphene transfer methods and anticipates future developmental prospects.
文摘Through literature analysis and case study, the introduction history, variety selection (high bush, half high bush, low bush) and regional cultivation techniques of blueberry in China were summarized, and the practical effects of precision cultivation (water and fertilizer integration, wild planting) and under-forest economic model (forest-blueberry-fungus system, ecological tourism) were evaluated. It provided a technical reference for expanding the planting scale of blueberry and improving the fruit quality.
基金supported from the Natural Science Foundation Project of Shanghai(Nos.23ZR1425300 and 22ZR1426100)Experimental Technical Team Construction Project of Shanghai Education Commission(No.10110N230080)+1 种基金National Natural Science Foundation of China(No.22075183)Research and Innovation Project of Shanghai Municipal Education Commission(No.2023ZKZD54).
文摘The addition of cold flow improvers(CFIs)is considered as the optimum strategy to improve the cold flow properties(CFPs)of diesel fuels,but this strategy is always limited by the required large dosage.To obtain low-dosage and high-efficiency CFIs for diesel,1,2,3,6-tetrahydrophthalic anhydride(THPA)was introduced as a third and polar monomer to enhance the depressive effects of alkyl methacrylatetrans anethole copolymers(C_(14)MC-TA).The terpolymers of alkyl methacrylate-trans anethole-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-TA-THPA)were synthesized and compared with the binary copolymers of C_(14)MC-TA and alkyl methacrylate-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-THPA).Results showed that C_(14)MC-THPA achieved the best depressive effects on the cold filter plugging point(CFPP)and solid point(SP)by 11℃and 16℃at a dosage of 1250 mg/L and monomer ratio of 6:1,while 1500mg/L C_(14)MC-TA(1:1)reached the optimal depressive effects on the CFPP and SP by 12℃and 18℃.THPA introduction significantly improved the depressive effects of C_(14)MC-TA.Lower dosages of C_(14)MCTA-THPA in diesel exerted better improvement effects on the CFPP and SP than that of C_(14)MC-TA and C_(14)MC-THPA.When the monomer ratio and dosage were 6:0.6:0.4 and 1000 mg/L,the improvement effect of C_(14)MC-TA-THPA on diesel reached the optimum level,and the CFPP and SP were reduced by 13℃and 19℃,respectively.A 3D nonlinear surface diagram fitted by a mathematical model was also used for the first time to better understand the relationships of monomer ratios,dosages,and depressive effects of CFIs in diesel.Surface analysis results showed that C_(14)MC-TA-THPA achieved the optimum depressive effects at a monomer ratio of 6:0.66:0.34 and dosage of 1000 mg/L,and the CFPP and SP decreased by 14℃ and 19℃,respectively.The predicted results were consistent with the actual ones.Additionally,the improvement mechanism of these copolymers in diesel was also explored.
基金the financial supports from National Key R&D Program for Young Scientists of China(Grant No.2022YFC3080900)National Natural Science Foundation of China(Grant No.52374181)+1 种基金BIT Research and Innovation Promoting Project(Grant No.2024YCXZ017)supported by Science and Technology Innovation Program of Beijing institute of technology under Grant No.2022CX01025。
文摘In this study,an inverse design framework was established to find lightweight honeycomb structures(HCSs)with high impact resistance.The hybrid HCS,composed of re-entrant(RE)and elliptical annular re-entrant(EARE)honeycomb cells,was created by constructing arrangement matrices to achieve structural lightweight.The machine learning(ML)framework consisted of a neural network(NN)forward regression model for predicting impact resistance and a multi-objective optimization algorithm for generating high-performance designs.The surrogate of the local design space was initially realized by establishing the NN in the small sample dataset,and the active learning strategy was used to continuously extended the local optimal design until the model converged in the global space.The results indicated that the active learning strategy significantly improved the inference capability of the NN model in unknown design domains.By guiding the iteration direction of the optimization algorithm,lightweight designs with high impact resistance were identified.The energy absorption capacity of the optimal design reached 94.98%of the EARE honeycomb,while the initial peak stress and mass decreased by 28.85%and 19.91%,respectively.Furthermore,Shapley Additive Explanations(SHAP)for global explanation of the NN indicated a strong correlation between the arrangement mode of HCS and its impact resistance.By reducing the stiffness of the cells at the top boundary of the structure,the initial impact damage sustained by the structure can be significantly improved.Overall,this study proposed a general lightweight design method for array structures under impact loads,which is beneficial for the widespread application of honeycomb-based protective structures.
文摘Purpose-Interface management is the process of managing communications,responsibilities and coordination of project parties,phases or physical entities which are dependent on one another.Interface management is a crucial part of managing any construction project-but particularly important for high-speed railway projects that often have several contractual parties and stakeholders,very long project timelines and huge upfront cost overlays.This paper discusses how various project interfaces were managed during the design and construction of the civil engineering infrastructure for the High Speed Two(HS2)project in the United Kingdom.Design/methodology/approach-The paper uses the case study methodology.Key interfaces on the HS2 project are grouped into various categories and the paper discusses how they were managed within the Area North Integrated Project Team(IPT)of the HS2 project made up of contractor Balfour Beatty VINCI(BBV),the Mott MacDonald SYSTRA Design Joint Venture(DJV)and client HS2 Ltd.3 different case studies drawn from across the IPT are used,each of them highlighting different interfaces and how these interfaces were managed.Findings-The paper shows how innovative technical designs and modern methods of construction were used to address some of the unique and peculiar challenges of designing a brand-new railway in the United Kingdom.Addressing the contrasting and often competing requirements of different stakeholders,coupled with challenging physical constraints of the very limited land available for the project and the use of a rarely used Act of Parliament in the delivery of the project required different approach to interface management.Collaboration and proactive stakeholder engagement are necessary for successful interface management on megaprojects.The authors posit that adopting an integrated approach to engineering and construction management is an essential ingredient for the successful delivery of high-speed railway projects.Originality/value-With many high-speed railway projects around the world coming up in the next few years,understanding the context and challenges for each country will help engineering and design managers adopt appropriate approaches for their projects.The lessons learned on the HS2 project are also transferable to other mega infrastructure projects with complex project interfaces.
基金Supported by the National Key Research and Development Program of China(2023YFB4104500,2023YFB4104502)the National Natural Science Foundation of China(22138013)the Taishan Scholar Project(ts201712020).
文摘Against the backdrop of escalating global climate change and energy crises,the resource utilization of carbon dioxide(CO_(2)),a major greenhouse gas,has become a crucial pathway for achieving carbon peaking and carbon neutrality goals.The hydrogenation of CO_(2)to methanol not only enables carbon sequestration and recycling,but also provides a route to produce high value-added fuels and basic chemical feedstocks,holding significant environmental and economic potential.However,this conversion process is thermodynamically and kinetically limited,and traditional catalyst systems(e.g.,Cu/ZnO/Al_(2)O_(3))exhibit inadequate activity,selectivity,and stability under mild conditions.Therefore,the development of novel high-performance catalysts with precisely tunable structures and functionalities is imperative.Metal-organic frameworks(MOFs),as crystalline porous materials with high surface area,tunable pore structures,and diverse metal-ligand compositions,have the great potential in CO_(2)hydrogenation catalysis.Their structural design flexibility allows for the construction of well-dispersed active sites,tailored electronic environments,and enhanced metal-support interactions.This review systematically summarizes the recent advances in MOF-based and MOF-derived catalysts for CO_(2)hydrogenation to methanol,focusing on four design strategies:(1)spatial confinement and in situ construction,(2)defect engineering and ion-exchange,(3)bimetallic synergy and hybrid structure design,and(4)MOF-derived nanomaterial synthesis.These approaches significantly improve CO_(2)conversion and methanol selectivity by optimizing metal dispersion,interfacial structures,and reaction pathways.The reaction mechanism is further explored by focusing on the three main reaction pathways:the formate pathway(HCOO*),the RWGS(Reverse Water Gas Shift reaction)+CO*hydrogenation pathway,and the trans-COOH pathway.In situ spectroscopic studies and density functional theory(DFT)calculations elucidate the formation and transformation of key intermediates,as well as the roles of active sites,metal-support interfaces,oxygen vacancies,and promoters.Additionally,representative catalytic performance data for MOFbased systems are compiled and compared,demonstrating their advantages over traditional catalysts in terms of CO_(2)conversion,methanol selectivity,and space-time yield.Future perspectives for MOF-based CO_(2)hydrogenation catalysts will prioritize two main directions:structural design and mechanistic understanding.The precise construction of active sites through multi-metallic synergy,defect engineering,and interfacial electronic modulation should be made to enhance catalyst selectivity and stability.In addition,advanced in situ characterization techniques combined with theoretical modeling are essential to unravel the detailed reaction mechanisms and intermediate behaviors,thereby guiding rational catalyst design.Moreover,to enable industrial application,challenges related to thermal/hydrothermal stability,catalyst recyclability,and cost-effective large-scale synthesis must be addressed.The development of green,scalable preparation methods and the integration of MOF catalysts into practical reaction systems(e.g.,flow reactors)will be crucial for bridging the gap between laboratory research and commercial deployment.Ultimately,multi-scale structure-performance optimization and catalytic system integration will be vital for accelerating the industrialization of MOF-based CO_(2)-to-methanol technologies.
基金supported by the National Key R&D Program of China(2023YFA1507400)the National Natural Science Foundation of China(Grant No.22325805,22441010,22408203)+2 种基金Beijing Natural Science Foundation(Grant No.JQ22003)the Haihe Laboratory of Sustainable Chemical Transformations(24HHWCSS00007)Tsinghua University Dushi Program,and Sinopec Group(PR20232572).
文摘The electrochemical oxidation of biomass-derived platform molecule 5-hydroxymethylfurfural(HMF)represents a crucial pathway for green transformation into high-value chemicals,yet its reaction pathway selectivity,efficiency,and catalyst stability are strongly dependent on the electrolyte pH environment.Under alkaline conditions,high OH−concentration facilitates preferential aldehyde group oxidation and efficient deprotonation,enabling highly efficient synthesis of 2,5-furandicarboxylic acid,but simultaneously induces HMF self-degradation and complicates product separation.As pH decreases,the reaction mechanism shifts toward enhanced hydroxymethyl oxidation,leading to intermediate accumulation(such as 5-hydroxymethyl-2-furancarboxylic acid,2,5-diformylfuran,and 5-formyl-2-furancarboxylic acid)with challenging selectivity control and significantly slowed reaction kinetics.This review comprehensively examines the systematic differences in HMF oxidation pathways and surface catalytic mechanisms across the full pH range from alkaline to acidic conditions.Addressing the distinct reaction characteristics and core challenges in alkaline,near-neutral,and acidic media,we systematically evaluate design strategies for high-efficiency electrocatalysts and explore reactor design aspects.Future research should focus on process integration(with tailored reactor design)for energy consumption reduction in alkaline systems,targeted synthesis of diverse oxidation products in near-neutral systems,and innovative catalyst development for acidic systems,thereby advancing the efficiency,selectivity,and practical application of HMF electrooxidation technologies across the entire pH spectrum through synergistic optimization of catalyst,reactor,and process.
基金supported by the National Natural Science Foundation of China[grant numbers 12071329,12471246].
文摘In mixture experiments,the observed response is determined by the relative proportions of the components,consequently rendering the experimental region a simplex.This paper focuses primarily on the optimal designs of mixture experiments that involve process variables.Prior research has extensively delved into optimal orthogonal block designs for some classic mixture models with process variables.Based on the framework of general blending models,this paper proposes a class of symmetric linear mixture models,which can be regarded as a generalization of many existing ones.Under the orthogonal blocking conditions,orthogonal block designs are devised through Latin squares in the presence of process variables.TheD-,A-,and E-optimality criteria are utilized to obtain optimal designs at the boundary of the simplex in the case of 3 components.As the values of the exponents change,numerically derived optimal design points are presented to illustrate the pattern of their variations,and to verify the consistency of the results with previous research on some specific symmetric general blending models.
基金supported by ZTE Industry-University-Institute Cooperation Funds under Grant No.IA20230921014。
文摘In this paper,we provide a comprehensive examination of the evolution of graphics Application Programming Interfaces(APIs).We begin by exploring traditional graphics APIs,elucidating their distinct features and inherent challenges.This sets the stage for a detailed exploration of modern graphics APIs,with a focus on four critical design principles.These principles are further analyzed through specific case studies and categorical examinations.The paper then introduces MoerEngine,a bespoke rendering engine,as a practical case to demonstrate the real-world application of these modern principles in software engineering.In conclusion,the study offers insights into the potential future trajectory of graphics APIs,spotlighting emerging design patterns and technological innovations.It also ventures to predict the development trends and capabilities of next-generation graphics APIs.
基金supported by the National Key R&D Project from the Minister of Science and Technology(2024YFA1211500)the National Natural Science Foundation of China(Grant Nos.62304130,62405158 and 62574123)+1 种基金the Shanghai youth science and technology star project(24QA2702800)Shanghai Key Laboratory of Chips and Systems for Intelligent Connected Vehicle。
文摘Memristors have emerged as a transformative technology in the realm of electronic devices,offering unique advantages such as fast switching speeds,low power consumption,and the ability to sensor-memory-compute.The applications span across non-volatile memory,neuromorphic computing,hardware security,and beyond,prompting memristors to become a versatile solution for next-generation computing and data storage systems.Despite enormous potential of memristors,the transition from laboratory prototypes to large-scale applications is challenging in terms of material stability,device reproducibility,and array scalability.This review systematically explores recent advancements in high-performance memristor technologies,focusing on performance enhancement strategies through material engineering,structural design,pulse protocol optimization,and algorithm control.We provide an in-depth analysis of key performance metrics tailored to specific applications,including non-volatile memory,neuromorphic computing,and hardware security.Furthermore,we propose a co-design framework that integrates device-level optimizations with operational-level improvements,aiming to bridge the gap between theoretical models and practical implementations.
文摘Compact size,high brightness,and wide field of view(FOV)are key requirements for long-wave infrared imagers used in military surveillance or night navigation.However,to meet the imaging requirements of high resolution and wide FOV,infrared optical systems often adopt complex optical lens groups,which will increase the size and weight of the optical system.In this paper,a strategy based on wavefront coding(WFC)is proposed to design a compact wide-FOV infrared imager.A cubic phase mask is inserted into the pupil plane of the infrared imager to correct the aberration.The simulated results show that,the WFC infrared imager has good imaging quality in a wide FOV of±16°.In addition,the WFC infrared imager achieves compactness with its 40 mm×40 mm×40 mm size.A fast focal ratio of 1 combined with an entrance pupil diameter of 25 mm ensures brightness.This work is of significance for designing a compact wide-FOV infrared imager.
基金supported by a grant from the National Science and Technology Major Project(Grant No.2024ZD0519800).
文摘Both large-scale prospective randomized controlled trials(RCTs)and smaller investigator-initiated trials are essential for evaluating the efficacy and safety of medical interventions.Robust protocols and statistical designs ensure the reliability of trial outcomes and improve the credibility of research findings.By reviewing the statistical approaches used in the TORCHLIGHT,NCC2167,and NeoTENNIS trials,this article illustrates the principles underlying large-sample confirmatory RCTs,small-sample exploratory adaptive designs,and single-arm two-stage designs.This discussion is aimed at helping researchers apply these design methods more effectively,to increase the likelihood of success in clinical studies.
