This article reports a new generation of Q460 multi-functional construction structural steel,which has high strength(yield strength larger than 460 MPa),excellent toughness(higher than 110 J/cm^(2) at-60 ℃),lower yie...This article reports a new generation of Q460 multi-functional construction structural steel,which has high strength(yield strength larger than 460 MPa),excellent toughness(higher than 110 J/cm^(2) at-60 ℃),lower yield ratio(lower than 0.8),good fire resistance(yield strength at 600 ℃ larger than two-thirds of its room-temperature yield strength)and better corrosion resistance.The eff ects of finish cooling temperature(FCT)on the microstructure and properties were studied by scanning electron microscopy(SEM),transmission electron microscopy(TEM),emission electron probe micro-analysis(EPMA),electron backscattering diff raction(EBSD),tensile tester,impact tester,periodic immersion cycle acceleration test and electrochemical experiment.The results show that the strength and toughness are simultaneously improved by decreasing the FCT due to more lath-like bainite with large number of dislocations,refined martensite/austenite(M/A)with higher carbon concentration and increased high angle boundaries.In addition,the fire resistance of the newly developed Q460 steel is obviously better than the conventional one,which is mainly due to non-recrystallized lath-like bainite with high dislocation density at elevated temperature.The corrosion resistance of the new Q460 steel is also improved due to the addition of Cu and Cr.展开更多
The effects of concrete's time-variant elastic modulus,casting structural components,assembling temporary shoring framework system,and shock by operating construction equipment on dynamic behavior of the reinforce...The effects of concrete's time-variant elastic modulus,casting structural components,assembling temporary shoring framework system,and shock by operating construction equipment on dynamic behavior of the reinforced concrete frame structure during construction were investigated. The dynamic tests of an eight-storey reinforced concrete frame structure during full-scaled stages of the sixth storey construction cycle were carried out by ambient vibration. Natural frequencies,corresponding mode shapes and damping ratio were determined by power spectrum processing the tested signal data in frequency domain. The changes of frequencies,mode shapes and damping ratios at different construction stages were given. The results show that natural frequencies and modal damping ratios reach the maximum at stage of casting fresh concrete,especially for higher modes. Modal damping ratios at each construction stage are less than 5% of those during usage.展开更多
The design quality of construction drawing of building structure is an important basis of engineering construction quality, which can fully reflect the design concept. Any problems existing in the design of constructi...The design quality of construction drawing of building structure is an important basis of engineering construction quality, which can fully reflect the design concept. Any problems existing in the design of construction drawing will affect the safety of building. At the same time, the design of construction drawing has certain technical content, which reflects the architects grasp of the scheme and the ability to apply technology. Therefore, in order to conscientiously implement the relevant regulations of national architectural design and improve the design quality of structural construction drawings, this paper analyzes the problems existing in the design of structural construction drawings of architectural engineering, and puts forward some improvement suggestions for reference by structural construction drawing designers.展开更多
The inherent teaching approach can no longer meet the demands of society.In this paper,current issues within the teaching landscape of architectural engineering technology in higher vocational colleges as well as the ...The inherent teaching approach can no longer meet the demands of society.In this paper,current issues within the teaching landscape of architectural engineering technology in higher vocational colleges as well as the policies and teaching demands that formed the basis of this model were analyzed.The study shows the importance of the implementation of the teaching model“promoting teaching and learning through competitions.”This model puts emphasis on the curriculum and teaching resources,while also integrating the teaching process and evaluation with competition.These efforts aim to drive education reform in order to better align with the objectives of vocational education personnel training,while also acting as a reference for similar courses.展开更多
As blockchain technology rapidly evolves,smart contracts have seen widespread adoption in financial transactions and beyond.However,the growing prevalence of malicious Ponzi scheme contracts presents serious security ...As blockchain technology rapidly evolves,smart contracts have seen widespread adoption in financial transactions and beyond.However,the growing prevalence of malicious Ponzi scheme contracts presents serious security threats to blockchain ecosystems.Although numerous detection techniques have been proposed,existing methods suffer from significant limitations,such as class imbalance and insufficient modeling of transaction-related semantic features.To address these challenges,this paper proposes an oversampling-based detection framework for Ponzi smart contracts.We enhance the Adaptive Synthetic Sampling(ADASYN)algorithm by incorporating sample proximity to decision boundaries and ensuring realistic sample distributions.This enhancement facilitates the generation of high-quality minority class samples and effectively mitigates class imbalance.In addition,we design a Contract Transaction Graph(CTG)construction algorithm to preserve key transactional semantics through feature extraction from contract code.A graph neural network(GNN)is then applied for classification.This study employs a publicly available dataset from the XBlock platform,consisting of 318 verified Ponzi contracts and 6498 benign contracts.Sourced from real Ethereum deployments,the dataset reflects diverse application scenarios and captures the varied characteristics of Ponzi schemes.Experimental results demonstrate that our approach achieves an accuracy of 96%,a recall of 92%,and an F1-score of 94%in detecting Ponzi contracts,outperforming state-of-the-art methods.展开更多
The construction of core-shell structure is an effective strategy for promoting the emission efficiency of upconversion nanocrystals(UCNCs). In this work, the UCNCs based on Nd-doping with a multilayer coreshell nanos...The construction of core-shell structure is an effective strategy for promoting the emission efficiency of upconversion nanocrystals(UCNCs). In this work, the UCNCs based on Nd-doping with a multilayer coreshell nanostructure are fabricated toward achieving efficient upconversion for 808 nm excitation, which have great potential for optical applications, especially photobiological applications.展开更多
During the construction of prefabricated building engineering, the quality of prefabricated building engineering is often affected by various internal and external factors which affect the sustainable development of t...During the construction of prefabricated building engineering, the quality of prefabricated building engineering is often affected by various internal and external factors which affect the sustainable development of the construction industry. With the advancement of Science and technology, the perfection of industrial chain and the improvement and innovation of architectural design concept, combined with the advantages of steel structure " light, convenient, smart and fast ", the development of fabricated steel structure in residential area is worth popularizing. Therefore, we should make great efforts to popularize the assembled steel structure housing in the urban construction level and promote the housing industrialization development, so as to realize the common development of our countrys housing industrys economic and social benefits.展开更多
To compensate for the imperfection of traditional bi-directional evolutionary structural optimization, material interpolation scheme and sensitivity filter functions are introduced. A suitable filter can overcome the ...To compensate for the imperfection of traditional bi-directional evolutionary structural optimization, material interpolation scheme and sensitivity filter functions are introduced. A suitable filter can overcome the checkerboard and mesh-dependency. And the historical information on accurate elemental sensitivity numbers are used to keep the objective function converging steadily. Apart from rational intervals of the relevant important parameters, the concept of distinguishing between active and non-active elements design is proposed, which can be widely used for improving the function and artistry of structures directly, especially for a one whose accurate size is not given. Furthermore, user-friendly software packages are developed to enhance its accessibility for practicing engineers and architects. And to reduce the time cost for large timeconsuming complex structure optimization, parallel computing is built-in in the MATLAB codes. The program is easy to use for engineers who may not be familiar with either FEA or structure optimization. And developers can make a deep research on the algorithm by changing the MATLAB codes. Several classical examples are given to show that the improved BESO method is superior for its handy and utility computer program software.展开更多
Ammonia plays an essential role in human production and life as a raw material for chemical fertilizers.The nitrate electroreduction to ammonia reaction(NO_(3)RR)has garnered attention due to its advantages over the H...Ammonia plays an essential role in human production and life as a raw material for chemical fertilizers.The nitrate electroreduction to ammonia reaction(NO_(3)RR)has garnered attention due to its advantages over the Haber-Bosch process and electrochemical nitrogen reduction reaction.Therefore,it represents a promising approach to safeguard the ecological environment by enabling the cycling of nitrogen species.This review begins by discussing the theoretical insights of the NO_(3)RR.It then summarizes recent advances in catalyst design and construction strategies,including alloying,structure engineering,surface engineering,and heterostructure engineering.Finally,the challenges and prospects in this field are presented.This review aims to guide for enhancing the efficiency of electrocatalysts in the NO_(3)RR,and offers insights for converting NO_(3)-to NH_(3).展开更多
The spiral assembly steel structure, a newly developed retaining wall for the rapid excavation of small-sized foundation pits in unsaturated soil, is presented. This new type of retaining structure is prefabricated in...The spiral assembly steel structure, a newly developed retaining wall for the rapid excavation of small-sized foundation pits in unsaturated soil, is presented. This new type of retaining structure is prefabricated in the factory and is assembled on site in the excavation of a pit. This retaining structure is composed of several prefabricated steel structural units, in which the adjacent steel structural units are joined with connectors. Each steel structural unit has one steel pipe in the radial direction and is welded to a single piece of steel plate. After full installation in situ, the retaining structure becomes a cylindrical steel structure. With the protection afforded by this new type of retaining structure, excavation work can be completed within 24 h to a depth up to 5 m. In order to verify the reliability and effectiveness of this new retaining structure, field construction tests were conducted in Beijing, China. The test construction was monitored. The monitoring program included measuring stress in the structure, lateral earth pressure, and lateral deformation of the surrounding soil. The monitoring data from the field test were compared with the theoretical results. The results show that the proposed new structure is reliable and effective.展开更多
Exploiting advanced nanocomposites isochronally integrating outstanding thermal conductivity(TC)and electromagnetic interference shielding effectiveness(EMI SE)can boost the cutting-edge application of phase change ma...Exploiting advanced nanocomposites isochronally integrating outstanding thermal conductivity(TC)and electromagnetic interference shielding effectiveness(EMI SE)can boost the cutting-edge application of phase change materials.Here,we report a tiramisu-like composite(GMP),where the typical“crust-and-cheese”hierarchical structure is replicated by an innovative two-step bidirectional freezing assembly(BFA)and compressive densification.Hierarchical-aligned graphene array(G-GA)with ultralow thermal resistance is fabricated through 1st BFA and graphitization.During the 2nd BFA,the MXene-CNF crosslinking network with hydrogen-bond actions is used for encapsulating polyethylene glycol(PEG)onto the microlayers of the G-GA skeleton.Remarkably,the microlaminated GMP4 achieves a recorded TC of 34.05 W m^(-1) K^(-1),unprecedented EMI SE of 87.4 dB,and preferable enthalpy density of 179.4 J cm^(-3),along with leakage-free function,and eminent thermal durability.Furthermore,the GMP-loaded equipment is demonstrated for efficient microelectronics cooling and sustainable solar energy utilization.This work opens new avenues for multiscale designing multifunctional macro-composites,broadening the application prospects in advanced electronics and solar energy utilization systems.展开更多
With the rapid development of China's economy and society, the development speed of industry is also accelerating. Before 1949, China was still an agricultural country, with little progress in industry. In just a ...With the rapid development of China's economy and society, the development speed of industry is also accelerating. Before 1949, China was still an agricultural country, with little progress in industry. In just a few decades, China's industry has made a qualitative leap, promoting China from an economically backward agricultural country into the world's largest industrial producer, and made remarkable achievements. The most direct manifestation of the development of industry is the establishment of a large number of factories, the factory will inevitably discharge a large amount of sewage, wastewater in the production process, resulting in water quality deterioration. These industrial wastewater contains a lot of lead, mercury and other harmful chemicals, and its emissions have also caused a certain degree of pollution to people's domestic water. If measures are not taken to purify water resources, it will harm people's health, especially for children, which can not be underestimated.展开更多
With the construction improvement of prefabricated building standards, the progress brought to society and the continuous improvement brought to industry, the technical level is constantly standardized, and the modeli...With the construction improvement of prefabricated building standards, the progress brought to society and the continuous improvement brought to industry, the technical level is constantly standardized, and the modeling and integration also meet the national requirements. In this way, the improvement of accuracy and quality will be more and more widely used in China, and prefabricated buildings will have a new world. In this process, enterprises need to pay more attention to prefabricated buildings, and combine with the current modern construction technology to fully grasp the technical points and control details, so as to effectively reduce the construction cost, reduce unnecessary waste of resources and shorten the construction period, improve the safety and reliability of buildings, and create a greener and diversified living environment. This paper makes an analysis.展开更多
An isospectral problem with four potentials is discussed. The corresponding hierarchy of nonlinearevolution equations is derived. It is shown that the AKNS, Levi, D-AKNS hierarchies and a new oneare reductions of the ...An isospectral problem with four potentials is discussed. The corresponding hierarchy of nonlinearevolution equations is derived. It is shown that the AKNS, Levi, D-AKNS hierarchies and a new oneare reductions of the above hierarchy. In each case the relevant Hamiltonian form is established bymaking use of the trase identity.展开更多
Constructing composite structures with intimate interfaces and favorable charge transfer routes is an effective way to obtain highly efficient photocatalysts.Herein,novel Z-scheme two-dimensional(2D)/2D WO_(3)/ZnIn_(2...Constructing composite structures with intimate interfaces and favorable charge transfer routes is an effective way to obtain highly efficient photocatalysts.Herein,novel Z-scheme two-dimensional(2D)/2D WO_(3)/ZnIn_(2)S_(4) nanocomposites were successfully designed,fabricated and characterized.Driven by the strong electrostatic interactions between the positively-charged 2D WO_(3) nanosheets and the negativelycharged 2D ZnIn_(2)S_(4) nanosheets,intimate contact interfaces were formed,which promoted the separation and transportation of electron–hole pairs in composites.The as-prepared WO_(3)/ZnIn_(2)S_(4) catalysts exhibited significantly enhanced photocatalytic H_(2) evolution activities under visible light irradiation in comparison to the single ZnIn_(2)S_(4) component.Moreover,cyclic tests revealed the high stability of the catalyst over four cycles of repeated use.These superior performances are ascribed to remarkably accelerated transfer and separation of charge carriers in the composites,which was verified by the results of photocurrent response,electrochemical impedance spectroscopy and photoluminescence.Electron spin resonance analyses proved the photocatalytic mechanism over 2D/2D WO_(3)/ZnIn_(2)S_(4) hybrids follows the special Z-scheme mode instead of the traditional double-transfer mode.This study is anticipated to offer fresh insight into the design and preparation of highly-efficient 2D ZnIn_(2)S_(4)-based Z-scheme catalysts for water splitting.展开更多
Constructing a befitting structure for efficient charge separation and transport is highly required for photocatalytic water splitting reactions to generate hydrogen (H_(2)).Herein,we successfully integrated a defecti...Constructing a befitting structure for efficient charge separation and transport is highly required for photocatalytic water splitting reactions to generate hydrogen (H_(2)).Herein,we successfully integrated a defective TiO_(2)/MoP heterojunction with highly conductive carbon cloth (CC),for constructing a panel reactor with charge transfer channels to boost H_(2) evolution.As expected,the behavior of photogenerated charge carriers is effectively steered,resulting in high-efficiency charge migration and separation,and consequently improving photocatalytic activity.The optimal TiO_(2)/MoP/CC exhibits a H_(2) generation rate of 14.7 μmol h^(−1) cm^(−2),up to 19 times higher than that of TiO_(2)/CC.Our work can open up ways to optimize the photocatalytic performance by developing novel non-powder-based photocatalyst systems with good stability and recyclability.展开更多
In this paper,porous BiVO_(4) nanorod arrays were encapsulated with FeOOH and ZnFe layered double hydroxide(ZnFe LDH)for the construction of hierarchical structures to achieve excellent transfer and separation of phot...In this paper,porous BiVO_(4) nanorod arrays were encapsulated with FeOOH and ZnFe layered double hydroxide(ZnFe LDH)for the construction of hierarchical structures to achieve excellent transfer and separation of photogenerated electron–hole pairs.With the decoration of FeOOH and ZnFe LDH,the as-prepared BVO/FeOOH/ZnFe LDH ternary photoanode exhibits enhanced visible light absorption,increased carrier density,lower charge transfer resistance,boosted charge injection,bulk separation efficiency,and enhanced PEC performance,as compared with that of bare BiVO_(4).The experimental results suggest improved electron transport and matched energy bands,along with the accelerated hole capture and improved water oxidation kinetics from cocatalysts.In addition,with the decoration of FeOOH and ZnFe LDH,the as-prepared BVO/FeOOH/ZnFe LDH ternary photoanode exhibited outstanding structural stability during the application process.This work could give a perspective for investigating photoelectrochemical water splitting in a BiVO_(4) heterostructural photoanode for an enhanced visible light response and boosted PEC performance.展开更多
The construction of highly conductive structures with excellent adsorption–catalytic properties to accelerate electron transfer and suppress polysulfide shuttle is considered as an effective strategy to achieve well-...The construction of highly conductive structures with excellent adsorption–catalytic properties to accelerate electron transfer and suppress polysulfide shuttle is considered as an effective strategy to achieve well-performing sodium–sulfur batteries.Herein,a self-supported tessellated N-doped carbon/CoSe_(2)(NCCS)is developed as a sulfur host for sodium–sulfur batteries by a simple deposition–selenization of lyophilized bacterial cellulose(BC),where NC acts as a conductive network to ensure the rapid initiation of efficient catalytic reactions at the tessellated CoSe_(2)interface and maintain good structural stability.展开更多
Supramolecular tessellation represents a newly emerging powerful tool for constructing crystalline and quasicrystalline structural aesthetics with molecular polygons/planigons.In turn,expanding such 2-periodic tessell...Supramolecular tessellation represents a newly emerging powerful tool for constructing crystalline and quasicrystalline structural aesthetics with molecular polygons/planigons.In turn,expanding such 2-periodic tessellation as tectonic layer to 3-periodic architecture of frameworks,promises the sublimation from visual beauty for pure appreciation to sophisticated performance of porous materials for real application,enabling us to build macroscopic behavior at the molecular scale.With the above foresight,we introduce herein a new discovery that integrating supramolecular tessellation and pillared-layer strategy assembles supramolecular frameworks(SFs).The tectonic layers are based on rhombille tessellation of hydrogen-bondings between FeII molecular building blocks and interstitial water molecules,showing a rare kagomédual(kgd)net.Under this strategy,we first observed that a new zlg 3D topology was born by pillaring with kgd layer.These SFs offer potential channel/voids for vips’respiration,inducing a reversible allosteric transformation from ligand substitution.The transformation alters significantly the spin state which was quantified by 57Fe Mössbauer spectroscopy,NMR,magnetic dilution and DFT calculations.These compounds show magnetic and chromatic bistability(see TOC),providing a broad scope towards multifuctional frameworks via multifarious supramolecular tessellation.展开更多
Lignocellulose is an ideal precursor for supercapacitor electrodes due to its diverse structures and abundant availability.For supercapacitors,particularly electric double-layer capacitors(EDLCs),pore structure is cri...Lignocellulose is an ideal precursor for supercapacitor electrodes due to its diverse structures and abundant availability.For supercapacitors,particularly electric double-layer capacitors(EDLCs),pore structure is critical.This review summarizes advances in lignocellulose-derived hierarchical porous carbon(LHPC)for supercapacitors,focusing on pore structure and future research directions.We discuss how pore structure influences supercapacitor performance,the activation methods for creating pores in LHPC,and review studies on optimizing pore structure for high-performance supercapacitors.Hierarchical porous carbon should feature a sufficient micropore surface area along with suitable mesoporous and macroporous surfaces to enhance rate performance while maintaining capacitance.This review is expected to actively advance the selection of lignocellulosic precursors and the development of optimized pore structure models,with the ultimate goal of enabling efficient production of lignocellulose-derived hierarchical porous carbon electrodes with superior properties.展开更多
基金financially supported by the Key Research and Development Program of Hebei Province of China(Grant No.18211019D)the"333 Talent Project"of Hebei(Grant No.A201803007)the Technical Development Program between HBIS Company Limited and NEU(Contract No.2019040200044)。
文摘This article reports a new generation of Q460 multi-functional construction structural steel,which has high strength(yield strength larger than 460 MPa),excellent toughness(higher than 110 J/cm^(2) at-60 ℃),lower yield ratio(lower than 0.8),good fire resistance(yield strength at 600 ℃ larger than two-thirds of its room-temperature yield strength)and better corrosion resistance.The eff ects of finish cooling temperature(FCT)on the microstructure and properties were studied by scanning electron microscopy(SEM),transmission electron microscopy(TEM),emission electron probe micro-analysis(EPMA),electron backscattering diff raction(EBSD),tensile tester,impact tester,periodic immersion cycle acceleration test and electrochemical experiment.The results show that the strength and toughness are simultaneously improved by decreasing the FCT due to more lath-like bainite with large number of dislocations,refined martensite/austenite(M/A)with higher carbon concentration and increased high angle boundaries.In addition,the fire resistance of the newly developed Q460 steel is obviously better than the conventional one,which is mainly due to non-recrystallized lath-like bainite with high dislocation density at elevated temperature.The corrosion resistance of the new Q460 steel is also improved due to the addition of Cu and Cr.
基金Project(50678064) supported by the National Natural Science Foundation of China
文摘The effects of concrete's time-variant elastic modulus,casting structural components,assembling temporary shoring framework system,and shock by operating construction equipment on dynamic behavior of the reinforced concrete frame structure during construction were investigated. The dynamic tests of an eight-storey reinforced concrete frame structure during full-scaled stages of the sixth storey construction cycle were carried out by ambient vibration. Natural frequencies,corresponding mode shapes and damping ratio were determined by power spectrum processing the tested signal data in frequency domain. The changes of frequencies,mode shapes and damping ratios at different construction stages were given. The results show that natural frequencies and modal damping ratios reach the maximum at stage of casting fresh concrete,especially for higher modes. Modal damping ratios at each construction stage are less than 5% of those during usage.
文摘The design quality of construction drawing of building structure is an important basis of engineering construction quality, which can fully reflect the design concept. Any problems existing in the design of construction drawing will affect the safety of building. At the same time, the design of construction drawing has certain technical content, which reflects the architects grasp of the scheme and the ability to apply technology. Therefore, in order to conscientiously implement the relevant regulations of national architectural design and improve the design quality of structural construction drawings, this paper analyzes the problems existing in the design of structural construction drawings of architectural engineering, and puts forward some improvement suggestions for reference by structural construction drawing designers.
文摘The inherent teaching approach can no longer meet the demands of society.In this paper,current issues within the teaching landscape of architectural engineering technology in higher vocational colleges as well as the policies and teaching demands that formed the basis of this model were analyzed.The study shows the importance of the implementation of the teaching model“promoting teaching and learning through competitions.”This model puts emphasis on the curriculum and teaching resources,while also integrating the teaching process and evaluation with competition.These efforts aim to drive education reform in order to better align with the objectives of vocational education personnel training,while also acting as a reference for similar courses.
基金supported by the Key Project of Joint Fund of the National Natural Science Foundation of China“Research on Key Technologies and Demonstration Applications for Trusted and Secure Data Circulation and Trading”(U24A20241)the National Natural Science Foundation of China“Research on Trusted Theories and Key Technologies of Data Security Trading Based on Blockchain”(62202118)+4 种基金the Major Scientific and Technological Special Project of Guizhou Province([2024]014)Scientific and Technological Research Projects from the Guizhou Education Department(Qian jiao ji[2023]003)the Hundred-Level Innovative Talent Project of the Guizhou Provincial Science and Technology Department(Qiankehe Platform Talent-GCC[2023]018)the Major Project of Guizhou Province“Research and Application of Key Technologies for Trusted Large Models Oriented to Public Big Data”(Qiankehe Major Project[2024]003)the Guizhou Province Computational Power Network Security Protection Science and Technology Innovation Talent Team(Qiankehe Talent CXTD[2025]029).
文摘As blockchain technology rapidly evolves,smart contracts have seen widespread adoption in financial transactions and beyond.However,the growing prevalence of malicious Ponzi scheme contracts presents serious security threats to blockchain ecosystems.Although numerous detection techniques have been proposed,existing methods suffer from significant limitations,such as class imbalance and insufficient modeling of transaction-related semantic features.To address these challenges,this paper proposes an oversampling-based detection framework for Ponzi smart contracts.We enhance the Adaptive Synthetic Sampling(ADASYN)algorithm by incorporating sample proximity to decision boundaries and ensuring realistic sample distributions.This enhancement facilitates the generation of high-quality minority class samples and effectively mitigates class imbalance.In addition,we design a Contract Transaction Graph(CTG)construction algorithm to preserve key transactional semantics through feature extraction from contract code.A graph neural network(GNN)is then applied for classification.This study employs a publicly available dataset from the XBlock platform,consisting of 318 verified Ponzi contracts and 6498 benign contracts.Sourced from real Ethereum deployments,the dataset reflects diverse application scenarios and captures the varied characteristics of Ponzi schemes.Experimental results demonstrate that our approach achieves an accuracy of 96%,a recall of 92%,and an F1-score of 94%in detecting Ponzi contracts,outperforming state-of-the-art methods.
基金financially supported in part by National Key R&D Program of China (Nos.2020YFA0406103,2017YFA0207301),NSFC (Nos.21725102,91961106,U1832156,22075267)Science and Technological Fund of Anhui Province for Outstanding Youth (No.2008085J05)+3 种基金Youth Innovation Promotion Association of CAS (No.2019444)Young Elite Scientist Sponsorship Program by CAST,China Postdoctoral Science Foundation (Nos.BH2340000099,BH2340000138)Users with Excellence Program of Hefei Science Center CAS (No.2020HSC-UE003)support from USTC Center for Micro- and Nanoscale Research and Fabrication。
文摘The construction of core-shell structure is an effective strategy for promoting the emission efficiency of upconversion nanocrystals(UCNCs). In this work, the UCNCs based on Nd-doping with a multilayer coreshell nanostructure are fabricated toward achieving efficient upconversion for 808 nm excitation, which have great potential for optical applications, especially photobiological applications.
文摘During the construction of prefabricated building engineering, the quality of prefabricated building engineering is often affected by various internal and external factors which affect the sustainable development of the construction industry. With the advancement of Science and technology, the perfection of industrial chain and the improvement and innovation of architectural design concept, combined with the advantages of steel structure " light, convenient, smart and fast ", the development of fabricated steel structure in residential area is worth popularizing. Therefore, we should make great efforts to popularize the assembled steel structure housing in the urban construction level and promote the housing industrialization development, so as to realize the common development of our countrys housing industrys economic and social benefits.
基金supported by the National Natural Science Foundation of China(No.51078311)
文摘To compensate for the imperfection of traditional bi-directional evolutionary structural optimization, material interpolation scheme and sensitivity filter functions are introduced. A suitable filter can overcome the checkerboard and mesh-dependency. And the historical information on accurate elemental sensitivity numbers are used to keep the objective function converging steadily. Apart from rational intervals of the relevant important parameters, the concept of distinguishing between active and non-active elements design is proposed, which can be widely used for improving the function and artistry of structures directly, especially for a one whose accurate size is not given. Furthermore, user-friendly software packages are developed to enhance its accessibility for practicing engineers and architects. And to reduce the time cost for large timeconsuming complex structure optimization, parallel computing is built-in in the MATLAB codes. The program is easy to use for engineers who may not be familiar with either FEA or structure optimization. And developers can make a deep research on the algorithm by changing the MATLAB codes. Several classical examples are given to show that the improved BESO method is superior for its handy and utility computer program software.
基金supported by the National Natural Science Foundation of China(22202151)Fundamental Research Program of Shanxi Province(202203021212243)。
文摘Ammonia plays an essential role in human production and life as a raw material for chemical fertilizers.The nitrate electroreduction to ammonia reaction(NO_(3)RR)has garnered attention due to its advantages over the Haber-Bosch process and electrochemical nitrogen reduction reaction.Therefore,it represents a promising approach to safeguard the ecological environment by enabling the cycling of nitrogen species.This review begins by discussing the theoretical insights of the NO_(3)RR.It then summarizes recent advances in catalyst design and construction strategies,including alloying,structure engineering,surface engineering,and heterostructure engineering.Finally,the challenges and prospects in this field are presented.This review aims to guide for enhancing the efficiency of electrocatalysts in the NO_(3)RR,and offers insights for converting NO_(3)-to NH_(3).
基金Project(41202220)supported by the National Natural Science Foundation of ChinaProject(20120022120003)supported by the Research Fund for the Doctoral Program of Higher Education,China+1 种基金Project(2652012065)supported by the Fundamental Research Funds for the Central Universities of ChinaProject(2013006)supported by the Research Fund for Key Laboratory on Deep Geo Drilling Technology,Ministry of Land and Resources,China
文摘The spiral assembly steel structure, a newly developed retaining wall for the rapid excavation of small-sized foundation pits in unsaturated soil, is presented. This new type of retaining structure is prefabricated in the factory and is assembled on site in the excavation of a pit. This retaining structure is composed of several prefabricated steel structural units, in which the adjacent steel structural units are joined with connectors. Each steel structural unit has one steel pipe in the radial direction and is welded to a single piece of steel plate. After full installation in situ, the retaining structure becomes a cylindrical steel structure. With the protection afforded by this new type of retaining structure, excavation work can be completed within 24 h to a depth up to 5 m. In order to verify the reliability and effectiveness of this new retaining structure, field construction tests were conducted in Beijing, China. The test construction was monitored. The monitoring program included measuring stress in the structure, lateral earth pressure, and lateral deformation of the surrounding soil. The monitoring data from the field test were compared with the theoretical results. The results show that the proposed new structure is reliable and effective.
基金support from the National Natural Science Foundation of China(No.21878218)the Tianjin Research Innovation Project for Postgraduate Students(No.2023KJ262)+2 种基金the State Grid Corporation of China’s Research Program(No.5419-202019385A)the Fundamental Research Funds for the Central Universities(No.92320006)the Tianjin Key Science and Technology Program(No.18ZXSZSF00030)。
文摘Exploiting advanced nanocomposites isochronally integrating outstanding thermal conductivity(TC)and electromagnetic interference shielding effectiveness(EMI SE)can boost the cutting-edge application of phase change materials.Here,we report a tiramisu-like composite(GMP),where the typical“crust-and-cheese”hierarchical structure is replicated by an innovative two-step bidirectional freezing assembly(BFA)and compressive densification.Hierarchical-aligned graphene array(G-GA)with ultralow thermal resistance is fabricated through 1st BFA and graphitization.During the 2nd BFA,the MXene-CNF crosslinking network with hydrogen-bond actions is used for encapsulating polyethylene glycol(PEG)onto the microlayers of the G-GA skeleton.Remarkably,the microlaminated GMP4 achieves a recorded TC of 34.05 W m^(-1) K^(-1),unprecedented EMI SE of 87.4 dB,and preferable enthalpy density of 179.4 J cm^(-3),along with leakage-free function,and eminent thermal durability.Furthermore,the GMP-loaded equipment is demonstrated for efficient microelectronics cooling and sustainable solar energy utilization.This work opens new avenues for multiscale designing multifunctional macro-composites,broadening the application prospects in advanced electronics and solar energy utilization systems.
文摘With the rapid development of China's economy and society, the development speed of industry is also accelerating. Before 1949, China was still an agricultural country, with little progress in industry. In just a few decades, China's industry has made a qualitative leap, promoting China from an economically backward agricultural country into the world's largest industrial producer, and made remarkable achievements. The most direct manifestation of the development of industry is the establishment of a large number of factories, the factory will inevitably discharge a large amount of sewage, wastewater in the production process, resulting in water quality deterioration. These industrial wastewater contains a lot of lead, mercury and other harmful chemicals, and its emissions have also caused a certain degree of pollution to people's domestic water. If measures are not taken to purify water resources, it will harm people's health, especially for children, which can not be underestimated.
文摘With the construction improvement of prefabricated building standards, the progress brought to society and the continuous improvement brought to industry, the technical level is constantly standardized, and the modeling and integration also meet the national requirements. In this way, the improvement of accuracy and quality will be more and more widely used in China, and prefabricated buildings will have a new world. In this process, enterprises need to pay more attention to prefabricated buildings, and combine with the current modern construction technology to fully grasp the technical points and control details, so as to effectively reduce the construction cost, reduce unnecessary waste of resources and shorten the construction period, improve the safety and reliability of buildings, and create a greener and diversified living environment. This paper makes an analysis.
基金The project supported by National Natural Science Foundation Committeethrough Nankai Institute of Mathematics
文摘An isospectral problem with four potentials is discussed. The corresponding hierarchy of nonlinearevolution equations is derived. It is shown that the AKNS, Levi, D-AKNS hierarchies and a new oneare reductions of the above hierarchy. In each case the relevant Hamiltonian form is established bymaking use of the trase identity.
基金financial supported by the National Science Foundation of China(11674398,51871250,51504106)the fund of the State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals(SKL-SPM-201808)the Fundamental Research Funds for the Central Universities of Central South University(2017zzts099).
文摘Constructing composite structures with intimate interfaces and favorable charge transfer routes is an effective way to obtain highly efficient photocatalysts.Herein,novel Z-scheme two-dimensional(2D)/2D WO_(3)/ZnIn_(2)S_(4) nanocomposites were successfully designed,fabricated and characterized.Driven by the strong electrostatic interactions between the positively-charged 2D WO_(3) nanosheets and the negativelycharged 2D ZnIn_(2)S_(4) nanosheets,intimate contact interfaces were formed,which promoted the separation and transportation of electron–hole pairs in composites.The as-prepared WO_(3)/ZnIn_(2)S_(4) catalysts exhibited significantly enhanced photocatalytic H_(2) evolution activities under visible light irradiation in comparison to the single ZnIn_(2)S_(4) component.Moreover,cyclic tests revealed the high stability of the catalyst over four cycles of repeated use.These superior performances are ascribed to remarkably accelerated transfer and separation of charge carriers in the composites,which was verified by the results of photocurrent response,electrochemical impedance spectroscopy and photoluminescence.Electron spin resonance analyses proved the photocatalytic mechanism over 2D/2D WO_(3)/ZnIn_(2)S_(4) hybrids follows the special Z-scheme mode instead of the traditional double-transfer mode.This study is anticipated to offer fresh insight into the design and preparation of highly-efficient 2D ZnIn_(2)S_(4)-based Z-scheme catalysts for water splitting.
基金supported in part by the National Natural Science Foundation of China(22002142)China Postdoctoral Science Foundation(2019M652570,2019M650172 and 2020T130605)+2 种基金Natural Science Foundation of Henan Province(202300410436)Support Plan for College Science and Technology Innovation Team of Henan Province(16IRTSTHN001)the Science&Technology Innovation Talent Plan of Henan Province(174200510018).
文摘Constructing a befitting structure for efficient charge separation and transport is highly required for photocatalytic water splitting reactions to generate hydrogen (H_(2)).Herein,we successfully integrated a defective TiO_(2)/MoP heterojunction with highly conductive carbon cloth (CC),for constructing a panel reactor with charge transfer channels to boost H_(2) evolution.As expected,the behavior of photogenerated charge carriers is effectively steered,resulting in high-efficiency charge migration and separation,and consequently improving photocatalytic activity.The optimal TiO_(2)/MoP/CC exhibits a H_(2) generation rate of 14.7 μmol h^(−1) cm^(−2),up to 19 times higher than that of TiO_(2)/CC.Our work can open up ways to optimize the photocatalytic performance by developing novel non-powder-based photocatalyst systems with good stability and recyclability.
基金financial support from the National Natural Science Foundation of China(51874050,22178031)Projects of International Cooperation and Exchanges of Changzhou(CZ20210036)+1 种基金Major Natural Science Research Projects of Universities in Jiangsu Province(21KJA480001)the 2021 Open Project of Jiangsu Key Laboratory for Carbon Based Functional Materials&Devices(KJS2153),Qinglan Project Foundation of Jiangsu Province.
文摘In this paper,porous BiVO_(4) nanorod arrays were encapsulated with FeOOH and ZnFe layered double hydroxide(ZnFe LDH)for the construction of hierarchical structures to achieve excellent transfer and separation of photogenerated electron–hole pairs.With the decoration of FeOOH and ZnFe LDH,the as-prepared BVO/FeOOH/ZnFe LDH ternary photoanode exhibits enhanced visible light absorption,increased carrier density,lower charge transfer resistance,boosted charge injection,bulk separation efficiency,and enhanced PEC performance,as compared with that of bare BiVO_(4).The experimental results suggest improved electron transport and matched energy bands,along with the accelerated hole capture and improved water oxidation kinetics from cocatalysts.In addition,with the decoration of FeOOH and ZnFe LDH,the as-prepared BVO/FeOOH/ZnFe LDH ternary photoanode exhibited outstanding structural stability during the application process.This work could give a perspective for investigating photoelectrochemical water splitting in a BiVO_(4) heterostructural photoanode for an enhanced visible light response and boosted PEC performance.
基金the National Natural Science Foundation of China(No.22005251,No.21773188,and No.21972111)the Chongqing Natural Science Foundation(cstc2021ycjh-bgzxm0164)the Central Universities Fundamental Research Funds(XDJK2019AA002).
文摘The construction of highly conductive structures with excellent adsorption–catalytic properties to accelerate electron transfer and suppress polysulfide shuttle is considered as an effective strategy to achieve well-performing sodium–sulfur batteries.Herein,a self-supported tessellated N-doped carbon/CoSe_(2)(NCCS)is developed as a sulfur host for sodium–sulfur batteries by a simple deposition–selenization of lyophilized bacterial cellulose(BC),where NC acts as a conductive network to ensure the rapid initiation of efficient catalytic reactions at the tessellated CoSe_(2)interface and maintain good structural stability.
基金supported by FNRS fellowships of chargéde Recherches(28109061 and 24918505)the initial founding of Zhejiang Sci-Tech University(11432932611902 and 11432932612014)and FNRS(CDR 33694457,PDR T.0095.21)+1 种基金the measurement of SEM and discussion.J.O.thanks the financial support of 2018-1.2.1-NKP-2018-00005the National Research,Development and Innovation Fund of Hungary,of CELSA/19/017.
文摘Supramolecular tessellation represents a newly emerging powerful tool for constructing crystalline and quasicrystalline structural aesthetics with molecular polygons/planigons.In turn,expanding such 2-periodic tessellation as tectonic layer to 3-periodic architecture of frameworks,promises the sublimation from visual beauty for pure appreciation to sophisticated performance of porous materials for real application,enabling us to build macroscopic behavior at the molecular scale.With the above foresight,we introduce herein a new discovery that integrating supramolecular tessellation and pillared-layer strategy assembles supramolecular frameworks(SFs).The tectonic layers are based on rhombille tessellation of hydrogen-bondings between FeII molecular building blocks and interstitial water molecules,showing a rare kagomédual(kgd)net.Under this strategy,we first observed that a new zlg 3D topology was born by pillaring with kgd layer.These SFs offer potential channel/voids for vips’respiration,inducing a reversible allosteric transformation from ligand substitution.The transformation alters significantly the spin state which was quantified by 57Fe Mössbauer spectroscopy,NMR,magnetic dilution and DFT calculations.These compounds show magnetic and chromatic bistability(see TOC),providing a broad scope towards multifuctional frameworks via multifarious supramolecular tessellation.
基金financial support for this research from the National Key Research Development Program of China(No.2021YFB3800300)Shanghai Pujiang Programme(No.23PJD045)the Shanghai Science and Technology Committee(No.24CL2900600).
文摘Lignocellulose is an ideal precursor for supercapacitor electrodes due to its diverse structures and abundant availability.For supercapacitors,particularly electric double-layer capacitors(EDLCs),pore structure is critical.This review summarizes advances in lignocellulose-derived hierarchical porous carbon(LHPC)for supercapacitors,focusing on pore structure and future research directions.We discuss how pore structure influences supercapacitor performance,the activation methods for creating pores in LHPC,and review studies on optimizing pore structure for high-performance supercapacitors.Hierarchical porous carbon should feature a sufficient micropore surface area along with suitable mesoporous and macroporous surfaces to enhance rate performance while maintaining capacitance.This review is expected to actively advance the selection of lignocellulosic precursors and the development of optimized pore structure models,with the ultimate goal of enabling efficient production of lignocellulose-derived hierarchical porous carbon electrodes with superior properties.
