Two-dimensional(2D) barcode technology is an electronic tagging technology based on combination of computer and optical technology. It is an important way of information collection and input. 2D barcode technology has...Two-dimensional(2D) barcode technology is an electronic tagging technology based on combination of computer and optical technology. It is an important way of information collection and input. 2D barcode technology has been widely used in various fields of logistics,production automation,and e-commerce,but it also has brought about a series of safety problems. Based on evolutionary encryption technology,this paper improved algorithm of traditional 2D barcode generation,to improve forgery- proof performance of 2D barcode. This algorithm is applied to agricultural products quality and safety traceability system and the results show that it is effective.展开更多
China possesses abundant heavy oil resources,yet faces challenges such as high viscosity,underdeveloped production technologies,and elevated development cost.Although the in-situ catalytic viscosity-reduction technolo...China possesses abundant heavy oil resources,yet faces challenges such as high viscosity,underdeveloped production technologies,and elevated development cost.Although the in-situ catalytic viscosity-reduction technology can address certain technical,environmental,and cost problems during the extraction process,the catalysts often suffer from poor stability and low catalytic efficiency.In this study,a green and simple room-temperature stirring method was employed to synthesize a class of highly efficient and stable 2D MOF catalysts,which possess the capability to conduct in-situ catalytic pyrolysis of heavy oil and reduce the viscosity.Under the condition of 160℃,a catalyst concentration of 0.5 wt%,and a hydrogen donor(tetralin)concentration of 2 wt%,the viscosity-reduction rate of Fe-MOF is as high as 89.09%,and it can decrease the asphaltene content by 8.42%.In addition,through the structural identification and analysis of crude oil asphaltenes,the causes for the high viscosity of heavy oil are explained at the molecular level.Through the analysis of catalytic products and molecular dynamics simulation,the catalytic mechanism is studied.It is discovered that Fe-MOF can interact with heavy oil macromolecules via coordination and pore-channel effects,facilitating their cracking and dispersal.Furthermore,synergistic interactions between Fe-MOF and the hydrogen donor facilitates hydrogenation reactions and enhances the viscosity-reducing effect.This study provides a novel strategy for boosting heavy oil recovery and underscores the potential of 2D MOFs in catalytic pyrolysis applications.展开更多
Drilling and blasting,characterized by their efficiency,ubiquity,and cost-effectiveness,have emerged as predominant techniques in rock excavation;however,they are accompanied by enormous destructive power.Accurately c...Drilling and blasting,characterized by their efficiency,ubiquity,and cost-effectiveness,have emerged as predominant techniques in rock excavation;however,they are accompanied by enormous destructive power.Accurately controlling the blasting energy and achieving the directional fracture of a rock mass have become common problems in the field.A two-dimensional blasting(2D blasting)technique was proposed that utilizes the characteristic that the tensile strength of a rock mass is significantly lower than its compressive strength.After blasting,only a 2D crack surface is generated along the predetermined direction,eliminating the damage to the reserved rock mass caused by conventional blasting.However,the interior of a natural rock mass is a"black box",and the process of crack propagation is difficult to capture,resulting in an unclear 2D blasting mechanism.To this end,a single-hole polymethyl methacrylate(PMMA)test piece was used to conduct a 2D blasting experiment with the help of a high-speed camera to capture the dynamic crack propagation process and the digital image correlation(DIC)method to analyze the evolution law of surface strain on the test piece.On this basis,a three-dimensional(3D)finite element model was established based on the progressive failure theory to simulate the stress,strain,damage,and displacement evolution process of the model under 2D blasting.The simulation results were consistent with the experimental results.The research results reveal the 2D blasting mechanism and provide theoretical support for the application of 2D blasting technology in the field of rock excavation.展开更多
The device-to-device(D2D)technology performs explicit communication between the terminal and the base station(BS)terminal,so there is no need to transmit data through the BS system.The establishment of a short-distanc...The device-to-device(D2D)technology performs explicit communication between the terminal and the base station(BS)terminal,so there is no need to transmit data through the BS system.The establishment of a short-distance D2D communication link can greatly reduce the burden on the BS server.At present,D2D is one of the key technologies in 5G technology and has been studied in depth.D2D communication reuses the resources of cellular users to improve system key parameters like utilization and throughput.However,repeated use of the spectrum and coexistence of cellular users can cause co-channel interference.Aiming at the interference problem under the constraint of fair resource allocation and improving the system throughput,this paper proposes an effective resource optimization scheme based on the firework method.The main idea is to expand the weighted sum rate and convert the allocated resource expression into fireworks to determine the correlation matrix.The simulation results show that,compared with the existing scheme,this scheme improves system performance by reducing interference.展开更多
The immense prospects of two-dimensional(2D)materials in the field of high-performance sensing stem from their unique layered structures and superior properties.Constructing heterostructures and refining sensor archit...The immense prospects of two-dimensional(2D)materials in the field of high-performance sensing stem from their unique layered structures and superior properties.Constructing heterostructures and refining sensor architectures are at the forefront of innovative research to enhance sensor performance.This review synthesizes the current literature,discussing the photovoltaic attributes,fabrication methods,analytical techniques and integration strategies pertinent to 2D materials.This comprehensive review of the operating principles of various sensors investigates the recent progress and deployment of these materials within diverse sensing devices,including chemical sensors,biosensors and optical sensors.Conclusively,this review serves as a valuable reference for understanding the applications and progress of 2D materials in high-performance sensors and explores their potential in interdisciplinary research.展开更多
Two-dimensional(2D)semiconductors,especially transition metal dichalcogenides,are the most competitive channel materials for post-silicon electronics due to their great miniaturization potential and advantages of high...Two-dimensional(2D)semiconductors,especially transition metal dichalcogenides,are the most competitive channel materials for post-silicon electronics due to their great miniaturization potential and advantages of high performance and low power consumption.The atomically thick structural advantage of 2D semiconductors also makes their strain tolerance far greater than that of silicon,making them an ideal platform for implementing and expanding strain technology in post-silicon electronics.The strain technology of 2D semiconductors can not only improve the mobility and on-current of a single device but also be more conveniently applied to the integration of 3D gate-all-around and complementary field-effect transistors.In recent years,a series of strain technologies with different characteristics have been developed for 2D semiconductors and transistor devices,including lattice mismatch,thermal expansion coefficient mismatch,substrate-induced stress technology,and process-induced stress.At present,it is necessary to sort out the existing technical foundation and propose strain strategies for 2D semiconductors that better suit industrialization and future 3D integration to meet the needs of high-performance post-silicon electronics.This review takes the mature strained silicon technology as a benchmark,systematically reviews the current strain technology of 2D semiconductors and devices,deeply analyzes the limitations of existing technologies,and proposes the development direction of strain technology for 2D semiconductors suitable for industrial applications and future 3D integration.展开更多
Nuclear magnetic resonance (NMR) has many advantages, such as little testing time, no harm to rock specimen, and is widely used in the measurement of reservoir pore structure. 3D printing also has many advantages, suc...Nuclear magnetic resonance (NMR) has many advantages, such as little testing time, no harm to rock specimen, and is widely used in the measurement of reservoir pore structure. 3D printing also has many advantages, such as repeating the printing the same attributes samples, forming sample by known rock pore structure, adding different pores or fractures to sample. For the study of fractured reservoir provides a new train of thought by combining NMR and 3D printing. Nuclear magnetic core analysis is an important work in the study of core, using a T2 spectrum at a certain echo time can also be found in the core fractures. The study, by CT scans to establish reservoir pore structure, based on the basic of adding different attitude fracture forming four fracture characteristics of rock sample, using 3D printing for solid sample, through the analysis of the nuclear magnetic resonance (NMR) of these sample, get the response characteristics of fracture characteristics on the T2 curve, the quantitative calculation of fracture porosity of rock sample, the result accord with to establish the model of fracture porosity is very good. For the study of fractured oil and gas reservoir development the new field.展开更多
Semiconductors have performed remarkably since the advent of two-dimensional(2D)materials with excellent electrical,optical,and thermal characteristics.This review summarizes the recent progress made in the 2D materia...Semiconductors have performed remarkably since the advent of two-dimensional(2D)materials with excellent electrical,optical,and thermal characteristics.This review summarizes the recent progress made in the 2D materials field,i.e.,graphene,transition metal dichalcogenides(TMDCs),and black phosphorus,focusing on their distinct thickness-dependent band structures,charge carrier mobilities,and mechanical properties.This has become a short but powerful interface for mobile devices with fast variations in our speaking circuits,and the power reaches from transistors,photodetectors,and solar cells together with digital electronics,radio-frequency devices,optoelectronics,and sensing technologies.This paper seeks to provide a clear perspective on fabrication,stability,and scale-up challenges by discussing theoretical and experimental approaches and highlighting challenges and innovative methods,including ultrasound-assisted strategies and heterostructure engineering.The present article performed and analysed a systematic literature review on key publications on the fundamental mechanisms and emerging applications of 2D materials in semiconductor technology.The review highlights the role these materials play in improving device performance,energy efficiency,and environmental friendliness.The paper concludes with a perspective on future directions,highlighting new research opportunities through advanced doping techniques and defect engineering to address current limitations and propel the broader adoption of 2D materials.This work sets another milestone for next-generation semiconductors.Another unique aspect of the study is its ability to bridge the gap between the fundamental characteristics of 2D semiconductors and real device-level integration.It draws attention to scalability,stability,and complementary metal oxide semiconductors(CMOS)compatibility difficulties that were not adequately considered in previous studies.The study discusses sophisticated tactics,including interface optimization and heterostructure engineering.A comparative analysis of 2D materials and their possible real-world semiconductor applications is also included in this chapter.展开更多
Microwave radiance data assimilation(DA)enhances initial conditions for numerical weather prediction(NWP)and shows great potential for improving forecasts in tropical regions like East Africa,where observational data ...Microwave radiance data assimilation(DA)enhances initial conditions for numerical weather prediction(NWP)and shows great potential for improving forecasts in tropical regions like East Africa,where observational data scarcity and complex tropical dynamics present significant challenges.Effectiveness of radiance assimilation is a function of variations in channel sensitivity to local atmospheric conditions and region-specific bias characteristics.However,microwave radiance assimilation in Limited-Area Models(LAMs)over East Africa remains largely unexplored.This study investigates the impact of assimilating microwave radiance channels with weighting functions peaking in the troposphere and lower stratosphere on rainfall forecasts over East Africa from a five-satellite constellation:the Microwave Temperature Sounder-2(MWTS-2)onboard Fengyun-3D(FY-3D),the Advanced Technology Microwave Sounder(ATMS)onboard JPSS,and the Advanced Microwave Sounding Unit-A(AMSU-A)onboard NOAA-15/18/19 satellites.The 6-h cycling DA experiments over a convectively active 15-day period show that assimilation of ATMS and AMSU-A radiances enhances representation of initial conditions,thereby reducing analysis and forecast errors.Assimilation of MWTS-2 radiances improves the analysis and forecasts further,especially for the tropospheric thermodynamic fields.The joint multi-microwave assimilation fills critical observation gaps over East Africa,allowing realistic simulations of diurnal precipitation trends,and capturing rainfall intensities exceeding 50 mm in 24 h,especially for T+12-h to T+24-h lead times.These findings are validated by a high-intensity rainfall case over Mandera,where spatio-temporal consistency is observed in instability and convection triggering.Forecast evaluation metrics have confirmed enhanced rainfall forecast skill for deep and rapidly developing convective systems.The study provides valuable insights into the gains of assimilating microwave radiance data over tropical regions,particularly in East Africa.展开更多
基金Supported by National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2012BAD35B04)
文摘Two-dimensional(2D) barcode technology is an electronic tagging technology based on combination of computer and optical technology. It is an important way of information collection and input. 2D barcode technology has been widely used in various fields of logistics,production automation,and e-commerce,but it also has brought about a series of safety problems. Based on evolutionary encryption technology,this paper improved algorithm of traditional 2D barcode generation,to improve forgery- proof performance of 2D barcode. This algorithm is applied to agricultural products quality and safety traceability system and the results show that it is effective.
基金supported by the National Natural Science Foundation of China(52174047)Sinopec Project(No.P23138).
文摘China possesses abundant heavy oil resources,yet faces challenges such as high viscosity,underdeveloped production technologies,and elevated development cost.Although the in-situ catalytic viscosity-reduction technology can address certain technical,environmental,and cost problems during the extraction process,the catalysts often suffer from poor stability and low catalytic efficiency.In this study,a green and simple room-temperature stirring method was employed to synthesize a class of highly efficient and stable 2D MOF catalysts,which possess the capability to conduct in-situ catalytic pyrolysis of heavy oil and reduce the viscosity.Under the condition of 160℃,a catalyst concentration of 0.5 wt%,and a hydrogen donor(tetralin)concentration of 2 wt%,the viscosity-reduction rate of Fe-MOF is as high as 89.09%,and it can decrease the asphaltene content by 8.42%.In addition,through the structural identification and analysis of crude oil asphaltenes,the causes for the high viscosity of heavy oil are explained at the molecular level.Through the analysis of catalytic products and molecular dynamics simulation,the catalytic mechanism is studied.It is discovered that Fe-MOF can interact with heavy oil macromolecules via coordination and pore-channel effects,facilitating their cracking and dispersal.Furthermore,synergistic interactions between Fe-MOF and the hydrogen donor facilitates hydrogenation reactions and enhances the viscosity-reducing effect.This study provides a novel strategy for boosting heavy oil recovery and underscores the potential of 2D MOFs in catalytic pyrolysis applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.52404155 and 52304111)State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining&Technology,Beijing(Grant No.XD2024006).
文摘Drilling and blasting,characterized by their efficiency,ubiquity,and cost-effectiveness,have emerged as predominant techniques in rock excavation;however,they are accompanied by enormous destructive power.Accurately controlling the blasting energy and achieving the directional fracture of a rock mass have become common problems in the field.A two-dimensional blasting(2D blasting)technique was proposed that utilizes the characteristic that the tensile strength of a rock mass is significantly lower than its compressive strength.After blasting,only a 2D crack surface is generated along the predetermined direction,eliminating the damage to the reserved rock mass caused by conventional blasting.However,the interior of a natural rock mass is a"black box",and the process of crack propagation is difficult to capture,resulting in an unclear 2D blasting mechanism.To this end,a single-hole polymethyl methacrylate(PMMA)test piece was used to conduct a 2D blasting experiment with the help of a high-speed camera to capture the dynamic crack propagation process and the digital image correlation(DIC)method to analyze the evolution law of surface strain on the test piece.On this basis,a three-dimensional(3D)finite element model was established based on the progressive failure theory to simulate the stress,strain,damage,and displacement evolution process of the model under 2D blasting.The simulation results were consistent with the experimental results.The research results reveal the 2D blasting mechanism and provide theoretical support for the application of 2D blasting technology in the field of rock excavation.
基金This work was supported by the King Saud University(in Riyadh,Saudi Arabia)through the Researcher Supporting Project Number(RSP-2021/387).
文摘The device-to-device(D2D)technology performs explicit communication between the terminal and the base station(BS)terminal,so there is no need to transmit data through the BS system.The establishment of a short-distance D2D communication link can greatly reduce the burden on the BS server.At present,D2D is one of the key technologies in 5G technology and has been studied in depth.D2D communication reuses the resources of cellular users to improve system key parameters like utilization and throughput.However,repeated use of the spectrum and coexistence of cellular users can cause co-channel interference.Aiming at the interference problem under the constraint of fair resource allocation and improving the system throughput,this paper proposes an effective resource optimization scheme based on the firework method.The main idea is to expand the weighted sum rate and convert the allocated resource expression into fireworks to determine the correlation matrix.The simulation results show that,compared with the existing scheme,this scheme improves system performance by reducing interference.
基金supported by the National Natural Science Foundation of China(No.62205091)the China Postdoctoral Science Foundation Funded Project(No.2022M710983)+1 种基金HeiLongJiang Postdoctoral Foundation(No.LBHZ22201)the Fundamental Research Foundation for Universities of Heilongjiang Province(No.2022-KYYWF-0121).
文摘The immense prospects of two-dimensional(2D)materials in the field of high-performance sensing stem from their unique layered structures and superior properties.Constructing heterostructures and refining sensor architectures are at the forefront of innovative research to enhance sensor performance.This review synthesizes the current literature,discussing the photovoltaic attributes,fabrication methods,analytical techniques and integration strategies pertinent to 2D materials.This comprehensive review of the operating principles of various sensors investigates the recent progress and deployment of these materials within diverse sensing devices,including chemical sensors,biosensors and optical sensors.Conclusively,this review serves as a valuable reference for understanding the applications and progress of 2D materials in high-performance sensors and explores their potential in interdisciplinary research.
基金the National Natural Science Foundation of China(92163205,52225206,52188101,52303362,62322402,52350301,92463308,52250398,62204012,62304019,52302162,and 52402169)the National Key Research and Development Program of China(2022YFA1203803,2024YFA1212600,and 2023YFF1500401)+6 种基金the special support from the Postdoctoral Science Foundation(2023TQ0007)the Postdoctoral Science Foundation(2023M740031)the Beijing Nova Program(20220484145 and 20230484478)the Young Elite Scientists Sponsorship Program by CAST(2022QNRC001)the Fundamental Research Funds for the Central Universities(FRF-TP-22-004C2,FRF-06500207,and FRF-IDRY-23-038)the State Key Lab for Advanced Metals and Materials(2023-Z05)the Postdoctoral Fellowship Program of CPSF(GZC20230233)。
文摘Two-dimensional(2D)semiconductors,especially transition metal dichalcogenides,are the most competitive channel materials for post-silicon electronics due to their great miniaturization potential and advantages of high performance and low power consumption.The atomically thick structural advantage of 2D semiconductors also makes their strain tolerance far greater than that of silicon,making them an ideal platform for implementing and expanding strain technology in post-silicon electronics.The strain technology of 2D semiconductors can not only improve the mobility and on-current of a single device but also be more conveniently applied to the integration of 3D gate-all-around and complementary field-effect transistors.In recent years,a series of strain technologies with different characteristics have been developed for 2D semiconductors and transistor devices,including lattice mismatch,thermal expansion coefficient mismatch,substrate-induced stress technology,and process-induced stress.At present,it is necessary to sort out the existing technical foundation and propose strain strategies for 2D semiconductors that better suit industrialization and future 3D integration to meet the needs of high-performance post-silicon electronics.This review takes the mature strained silicon technology as a benchmark,systematically reviews the current strain technology of 2D semiconductors and devices,deeply analyzes the limitations of existing technologies,and proposes the development direction of strain technology for 2D semiconductors suitable for industrial applications and future 3D integration.
文摘采用单因素法和响应面法相结合,对合成标题化合物的工艺条件进行优化。在单因素的实验基础上,再采用响应面法对原料配比、反应时间和反应后处理p H这3个关键因素进行优化分析,得到了标题化合物收率的计算模型,并得到优化条件:原料物质的量配比为n(2-氨基间苯二酚盐酸盐)∶n(乙基黄原酸钾)=1∶1.42,反应时间为4 h,反应后处理调节至p H 5,此条件下合成产率为65.28%。该合成工艺条件产率较高且稳定,可作为合成标题化合物的实验依据。
文摘Nuclear magnetic resonance (NMR) has many advantages, such as little testing time, no harm to rock specimen, and is widely used in the measurement of reservoir pore structure. 3D printing also has many advantages, such as repeating the printing the same attributes samples, forming sample by known rock pore structure, adding different pores or fractures to sample. For the study of fractured reservoir provides a new train of thought by combining NMR and 3D printing. Nuclear magnetic core analysis is an important work in the study of core, using a T2 spectrum at a certain echo time can also be found in the core fractures. The study, by CT scans to establish reservoir pore structure, based on the basic of adding different attitude fracture forming four fracture characteristics of rock sample, using 3D printing for solid sample, through the analysis of the nuclear magnetic resonance (NMR) of these sample, get the response characteristics of fracture characteristics on the T2 curve, the quantitative calculation of fracture porosity of rock sample, the result accord with to establish the model of fracture porosity is very good. For the study of fractured oil and gas reservoir development the new field.
文摘Semiconductors have performed remarkably since the advent of two-dimensional(2D)materials with excellent electrical,optical,and thermal characteristics.This review summarizes the recent progress made in the 2D materials field,i.e.,graphene,transition metal dichalcogenides(TMDCs),and black phosphorus,focusing on their distinct thickness-dependent band structures,charge carrier mobilities,and mechanical properties.This has become a short but powerful interface for mobile devices with fast variations in our speaking circuits,and the power reaches from transistors,photodetectors,and solar cells together with digital electronics,radio-frequency devices,optoelectronics,and sensing technologies.This paper seeks to provide a clear perspective on fabrication,stability,and scale-up challenges by discussing theoretical and experimental approaches and highlighting challenges and innovative methods,including ultrasound-assisted strategies and heterostructure engineering.The present article performed and analysed a systematic literature review on key publications on the fundamental mechanisms and emerging applications of 2D materials in semiconductor technology.The review highlights the role these materials play in improving device performance,energy efficiency,and environmental friendliness.The paper concludes with a perspective on future directions,highlighting new research opportunities through advanced doping techniques and defect engineering to address current limitations and propel the broader adoption of 2D materials.This work sets another milestone for next-generation semiconductors.Another unique aspect of the study is its ability to bridge the gap between the fundamental characteristics of 2D semiconductors and real device-level integration.It draws attention to scalability,stability,and complementary metal oxide semiconductors(CMOS)compatibility difficulties that were not adequately considered in previous studies.The study discusses sophisticated tactics,including interface optimization and heterostructure engineering.A comparative analysis of 2D materials and their possible real-world semiconductor applications is also included in this chapter.
基金Supported by the National Natural Science Foundation of China(U2442218 and U2442601)。
文摘Microwave radiance data assimilation(DA)enhances initial conditions for numerical weather prediction(NWP)and shows great potential for improving forecasts in tropical regions like East Africa,where observational data scarcity and complex tropical dynamics present significant challenges.Effectiveness of radiance assimilation is a function of variations in channel sensitivity to local atmospheric conditions and region-specific bias characteristics.However,microwave radiance assimilation in Limited-Area Models(LAMs)over East Africa remains largely unexplored.This study investigates the impact of assimilating microwave radiance channels with weighting functions peaking in the troposphere and lower stratosphere on rainfall forecasts over East Africa from a five-satellite constellation:the Microwave Temperature Sounder-2(MWTS-2)onboard Fengyun-3D(FY-3D),the Advanced Technology Microwave Sounder(ATMS)onboard JPSS,and the Advanced Microwave Sounding Unit-A(AMSU-A)onboard NOAA-15/18/19 satellites.The 6-h cycling DA experiments over a convectively active 15-day period show that assimilation of ATMS and AMSU-A radiances enhances representation of initial conditions,thereby reducing analysis and forecast errors.Assimilation of MWTS-2 radiances improves the analysis and forecasts further,especially for the tropospheric thermodynamic fields.The joint multi-microwave assimilation fills critical observation gaps over East Africa,allowing realistic simulations of diurnal precipitation trends,and capturing rainfall intensities exceeding 50 mm in 24 h,especially for T+12-h to T+24-h lead times.These findings are validated by a high-intensity rainfall case over Mandera,where spatio-temporal consistency is observed in instability and convection triggering.Forecast evaluation metrics have confirmed enhanced rainfall forecast skill for deep and rapidly developing convective systems.The study provides valuable insights into the gains of assimilating microwave radiance data over tropical regions,particularly in East Africa.
