This paper adopts server-side Java programming model: mod e 1- view-cont roller to construct welybased shopping system framework. Using servlets, Java server pages (JSPs) and JavaBeantechnologies, we provide a standar...This paper adopts server-side Java programming model: mod e 1- view-cont roller to construct welybased shopping system framework. Using servlets, Java server pages (JSPs) and JavaBeantechnologies, we provide a standard, open, robust and cross-platform architecture. It can guarantee system- independence. Presented framework provides a clean separation of presentation from business logic which meets user's taste by changing user interface frequenctly, and enables more functions to be conventiently added in future.展开更多
CRESDA Application System of CBERS-1 was established in 1999. During the operation of the system for more than two years, about 240 000 scenes of CBERS-1 Level 0 data have been archived and more than 13 000 scenes of ...CRESDA Application System of CBERS-1 was established in 1999. During the operation of the system for more than two years, about 240 000 scenes of CBERS-1 Level 0 data have been archived and more than 13 000 scenes of Level 2 products have been ordered by end users from different application fields.In this paper, the typical examples of applications in crop yield estimation,calamity alleviation, resources survey and protection, environment monitoring and continuable development, and urban planning are mainly described.展开更多
Considering the characteristics of deep thick top coal roadway,in which the high ground stress,coal seam with low strength,and a large range of surrounding rock fragmentation,the pressure relief anchor box beam suppor...Considering the characteristics of deep thick top coal roadway,in which the high ground stress,coal seam with low strength,and a large range of surrounding rock fragmentation,the pressure relief anchor box beam support system with high strength is developed.The high-strength bearing characteristics and coupling yielding support mechanism of this support system are studied by the mechanical tests of composite members and the combined support system.The test results show that under the coupling effect of support members,the peak stress of the box-shaped support beam in the anchor box beam is reduced by 21.9%,and the average deformation is increased by 135.0%.The ultimate bending bearing capacity of the box-shaped support beam is 3.5 times that of traditional channel beam.The effective compressive stress zone applied by the high prestressed cable is expanded by 26.4%.On this basis,the field support comparison test by the anchor channel beam,the anchor I-shaped beam and the anchor box beam are carried out.Compared with those of the previous two,the surrounding rock convergence of the latter is decreased by 41.2%and 22.2%,respectively.The field test verifies the effectiveness of the anchor box beam support system.展开更多
【Objectives】Rose(Rosa hybrida L.)is a beautiful and widely cultivated flowering plant around the world whose quality is of great commercial importance.The objective of this study was to investigate the impact of fol...【Objectives】Rose(Rosa hybrida L.)is a beautiful and widely cultivated flowering plant around the world whose quality is of great commercial importance.The objective of this study was to investigate the impact of foliar application of calcium nitrate on the quality and postharvest life of two rose varieties(cvs.Samurai,and Jumilia)in a soilless culture system.【Methods】The research used a hydroponic culture method,the roses plants were grown in Hoagland nutrient solution containing 50%less Ca for a total span of 4 months.One month was dedicated to plant acclimatization,and 3 months for spray treatment.Two rose varieties(Rosa hybrida L.),cvs.Samurai and Jumilia plants were used as test materials and planted in pots containing 100%perlite(3-5 mm).After one month of culture,160 mg/kg CaNO3 solution was sprayed,and each treatment corresponded to the first,second,and third harvests,respectively.The plant and flower growth indicators and flower vase life were investigated after each harvesting immediately.【Results】A positive impact of foliar-applied Ca on stem characteristics,pedicel dimensions,corolla size,flower attributes,and vase life was found.Furthermore,a general trend was observed,wherein an increase in the number of harvesting stages led to improved traits.Notably,Jumilia rose consistently exhibited lower values for all studied traits,except for flower vase life,in comparison to the Samurai rose.While there were no significant differences in length values between Samurai and Jumilia roses due to calcium foliar application across the three harvesting stages.Duncan’s grouping revealed a specific effect on Jumilia roses during the third harvest stage.Calcium fertilizer significantly increased photosynthesis rates of of rose leaves in the calcium treatments compared with the control treatment.【Conclusions】Foliar spraying of calcium nitrate is an effective measure to promote the growth of roses and improve the yield,quality and bottle life of fresh cut flowers.展开更多
Diamond combines many unique properties,including high stability,strong optical dispersion,excellent mechanical strength,and outstanding thermal conductivity.Its structure,surface groups,and electrical conductivity ar...Diamond combines many unique properties,including high stability,strong optical dispersion,excellent mechanical strength,and outstanding thermal conductivity.Its structure,surface groups,and electrical conductivity are also tunable,increasing its functional versatility.These make diamond and its related materials,such as its composites,highly promising for various applications in energy fields.This review summarizes recent advances and key achievements in energy storage and conversion,covering electrochemical energy storage(e.g.,batteries and supercapacitors),electrocatalytic energy conversion(e.g.,CO_(2)and nitrogen reduction reactions),and solar energy conversion(e.g.,photo-(electro)chemical CO_(2)and nitrogen reduction reactions,and solar cells).Current challenges and prospects related to the synthesis of diamond materials and the technologies for their energy applications are outlined and discussed.展开更多
Background Zonal application maps are designed to represent field variability using key variables that can be translated into tailored management practices.For cotton,zonal maps for crop growth regulator(CGR)applicati...Background Zonal application maps are designed to represent field variability using key variables that can be translated into tailored management practices.For cotton,zonal maps for crop growth regulator(CGR)applications under variable-rate(VR)strategies are commonly based exclusively on vegetation indices(VIs)variability.However,VIs often saturate in dense crop vegetation areas,limiting their effectiveness in distinguishing variability in crop growth.This study aimed to compare unsupervised framework(UF)and supervised framework(SUF)approaches for generat-ing zonal application maps for CGR under VR conditions.During 2022-2023 agricultural seasons,an UF was employed to generate zonal maps based on locally collected field data on plant height of cotton,satellite imagery,soil texture,and phenology data.Subsequently,a SUF(based on historical data between 2020-2021 to 2022-2023 agricultural seasons)was developed to predict plant height using remote sensing and phenology data,aiming to replicate same zonal maps but without relying on direct field measurements of plant height.Both approaches were tested in three fields and on two different dates per field.Results The predictive model for plant height of SUF performed well,as indicated by the model metrics.However,when comparing zonal application maps for specific field-date combinations,the predicted plant height exhibited lower variability compared with field measurements.This led to variable compatibility between SUF maps,which utilized the model predictions,and the UF maps,which were based on the real field data.Fields characterized by much pronounced soil texture variability yielded the highest compatibility between the zonal application maps produced by both SUF and UF approaches.This was predominantly due to the greater consistency in estimating plant development patterns within these heterogeneous field environments.While VR application approach can facilitate product savings during the application operation,other key factors must be considered.These include the availability of specialized machinery required for this type of applications,as well as the inherent operational costs associated with applying a single CGR product which differs from the typical uniform rate applications that often integrate multi-ple inputs.Conclusion Predictive modeling shows promise for assisting in the creation of zonal application maps for VR of CGR applications.However,the degree of agreement with the actual variability in crop growth found in the field should be evaluated on a field-by-field basis.The SUF approach,which is based on plant heigh prediction,demonstrated potential for supporting the development of zonal application maps for VR of CGR applications.However,the degree to which this approach aligns itself with the actual variability in crop growth observed in the field may vary,necessi-tating field-by-field evaluation.展开更多
Based on the characteristics of large flow rate , low head , short annual operation time , and high reliability of the city flood-control pumping stations , a new-type shaft tubular pumping system featuring a shaft su...Based on the characteristics of large flow rate , low head , short annual operation time , and high reliability of the city flood-control pumping stations , a new-type shaft tubular pumping system featuring a shaft suction box and a siphon-type discharge passage with a vacuum breaker as the cutoff device was developed , which possesses such advantages as simple structure , reliable cutoff , and high energy performance.Taking some pumping stations as the case studies , in the light of the specified operation conditions , the hydraulic optimal design of the shaft-type tubular pumping system was determined and the optimized shape of the system was recommended.The performance prediction based on the computational fluid dynamics methodology was determined and the model test verification was conducted.The results show that the predicted data agree with the experimental head and efficiency so that both methods can be used to determine the performance of a real pumping station.Finally , the in-situ measurements of a pumping station during the commissioning period further verified that the shaft-type tubular pumping station with a siphon discharge passage is of higher efficiency , more reliable and stable.展开更多
Application of thermal electrochemical equation to metal-hydride half-cell system was investigated, and the influence of state of charge on the thermal electrochemical performance of hydrogen storage materials was stu...Application of thermal electrochemical equation to metal-hydride half-cell system was investigated, and the influence of state of charge on the thermal electrochemical performance of hydrogen storage materials was studied. The results show that both the absolute value of the molar enthalpy change and the internal resistance of evolution hydrogen reaction are less than that of absorption hydrogen reaction at the same state of charge. The molar reaction enthalpy change of absorption and evolution of hydride electrode change contrarily with the enhancement of filling degree of hydrogen in hydride electrode. The relation curve of molar reaction enthslpy change to state of charge, both absorption and evolution hydrogen reaction, is close to a constant when the state of charge is 10%- 60%, and during state of charge below 10% or state of charge above 60%, the molar reaction enthalpy change varies sharply. Meanwhile, the internal resistance of electrode reaction has an ascending trend with the enhancement on filling degree of hydrogen in hydride electrode in both absorption and evolution hydrogen reaction.展开更多
In this paper the application of a cleaning system which was made up of a centrifugal fan with double channel and one sieve to 4LZ-3.5 combine was introduced. This cleaning system with double channel compared with the...In this paper the application of a cleaning system which was made up of a centrifugal fan with double channel and one sieve to 4LZ-3.5 combine was introduced. This cleaning system with double channel compared with the traditional air-sieve cleaning system of combines may omit one two sieves and simplify the transmission mechanism. It is also compared with the present cleaning system with double channel applied to some combines, such as the Commandor 112CS/ 228CS combines of Claas Corporation in Germany and the MAXIMIZERTMombincs of John Deerc company in U.S.A. It may omit one sieve and the preclcaner and simlify the transmission mechanism. The measuring results indicated that the cleaning ratio of wheat grain is 99.1% and the cleaning loss ratio of wheat is 0.17% when the feed rate is 4.01 kg/ s.展开更多
This paper presents the networking observation capabilities of Chinese ocean satellites and their diverse applications in ocean disaster prevention,ecological monitoring,and resource development.Since the inaugural la...This paper presents the networking observation capabilities of Chinese ocean satellites and their diverse applications in ocean disaster prevention,ecological monitoring,and resource development.Since the inaugural launch in 2002,China has achieved substantial advancements in ocean satellite technology,forming an observation system composed of the HY-1,HY-2,and HY-3 series satellites.These satellites are integral to global ocean environmental monitoring due to their high resolution,extensive coverage,and frequent observations.Looking forward,China aims to further enhance and expand its ocean satellite capabilities through ongoing projects to support global environmental protection and sustainable development.展开更多
Manuel C.Molles Jr.所著的Ecology:Concepts and Applications(《生态学:概念与应用》)在教材与网络资源的建设方面进行了有益的尝试,其主教材及辅助教学资源的设计理念值得借鉴。主教材从1999年到2008年出版了4版,主教材内容及版本更...Manuel C.Molles Jr.所著的Ecology:Concepts and Applications(《生态学:概念与应用》)在教材与网络资源的建设方面进行了有益的尝试,其主教材及辅助教学资源的设计理念值得借鉴。主教材从1999年到2008年出版了4版,主教材内容及版本更新快,力求及时反映学科前沿水平的新技术、新知识;正文内容和版式编排设计以读者为本,注重为学生服务;网上辅助教学资源围绕主教材的系列产品进行整体设计,体现利教利学的建设理念,既为教师教学提供帮助和指导,也重视给予学生自我发挥的空间,网站展示条理清晰,内容布局规范,内容介绍注重以读者为中心,满足不同客户的需求。展开更多
Electrospinning technology has emerged as a promising method for fabricating flexible lithium-ion batter-ies(FLIBs)due to its ability to create materials with desir-able properties for energy storage applications.FLIB...Electrospinning technology has emerged as a promising method for fabricating flexible lithium-ion batter-ies(FLIBs)due to its ability to create materials with desir-able properties for energy storage applications.FLIBs,which are foldable and have high energy densities,are be-coming increasingly important as power sources for wear-able devices,flexible electronics,and mobile energy applica-tions.Carbon materials,especially carbon nanofibers,are pivotal in improving the performance of FLIBs by increas-ing electrical conductivity,chemical stability,and surface area,as well as reducing costs.These materials also play a significant role in establishing conducting networks and im-proving structural integrity,which are essential for extend-ing the cycle life and enhancing the safety of the batteries.This review considers the role of electrospinning in the fabrication of critical FLIB components,with a particular emphasis on the integration of carbon materials.It explores strategies to optimize FLIB performance by fine-tuning the electrospinning para-meters,such as electric field strength,spinning rate,solution concentration,and carbonization process.Precise control over fiber properties is crucial for enhancing battery reliability and stability during folding and bending.It also highlights the latest research findings in carbon-based electrode materials,high-performance electrolytes,and separator structures,discussing the practical challenges and opportunities these materials present.It underscores the significant impact of carbon materials on the evolution of FLIBs and their potential to shape future energy storage technologies.展开更多
Carbon materials are a key component in energy storage and conversion devices and their microstructure plays a crucial role in determining device performance.However,traditional carbon materials are unable to meet the...Carbon materials are a key component in energy storage and conversion devices and their microstructure plays a crucial role in determining device performance.However,traditional carbon materials are unable to meet the requirements for applications in emerging fields such as renewable energy and electric vehicles due to limitations including a disordered structure and uncontrolled defects.With an aim of realizing devisable structures,adjustable functions,and performance breakthroughs,superstructured carbons is proposed and represent a category of carbon-based materials,characterized by precisely-built pores,networks,and interfaces.Superstructured carbons can overcome the limitations of traditional carbon materials and improve the performance of energy storage and conversion devices.We review the structure-activity relationships of superstructured carbons and recent research advances from three aspects including a precisely customized pore structure,a dense carbon network framework,and a multi-component highly coupled interface between the different components.Finally,we provide an outlook on the future development of and practical challenges in energy storage and conversion devices.展开更多
This study investigates the potential of metal additives in acrylonitrile butadiene styrene(ABS)polymer fuel to enhance hybrid rocket motor(HRM)performance through computational analysis,Chemical Equilibrium with Appl...This study investigates the potential of metal additives in acrylonitrile butadiene styrene(ABS)polymer fuel to enhance hybrid rocket motor(HRM)performance through computational analysis,Chemical Equilibrium with Applications(CEA),software.ABS was selected as the base fuel due to its thermoplastic nature,which allows for the creation of complex fuel geometries through 3D printing,offering significant flexibility in fuel design.Hybrid rockets,which combine a solid fuel with a liquid oxidiser,offer advantages in terms of operational simplicity and safety.However,conventional polymer fuels often exhibit low regression rates and suboptimal combustion efficiencies.In this research,we evaluated a range of metal additives-aluminium(Al),boron(B),nickel(Ni),copper(Cu),and iron(Fe)-at chamber pressures ranging from 1 to 30 bar and oxidiser-to-fuel(O/F)ratios between 1.1 and 12,resulting in 1800 unique test conditions.The main performance parameters used to assess each formulation were characteristic velocity(C^(*))and adiabatic flame temperature.The results revealed that each test produced a different optimum O/F ratio,with most ratios falling between 4 and 6.The highest performance was achieved at a chamber pressure of 30 bar across all formulations.Among the additives,Al and B demonstrated significant potential for improved combustion performance with increasing metal loadings.In contrast,Fe,Cu,and Ni reached optimal performance at a minimum loading of 1%.Future work includes investigating B-Al metal composites as additives into the ABS base polymer fuel,and doing experimental validation tests where the metallised ABS polymer fuel is 3D printed.展开更多
The traditional stability analysis method of geogrid reinforced slopes does not consider the effect of lateral swelling,so it is not applicable to reinforced expansive soil slopes.This paper reports a new stability an...The traditional stability analysis method of geogrid reinforced slopes does not consider the effect of lateral swelling,so it is not applicable to reinforced expansive soil slopes.This paper reports a new stability analysis method for geogrid reinforced expansive soil slopes.The additional pullout force of the free zone due to the lateral swelling and the anti-pullout safety factor of each geogrid layer were obtained by ensuring the overall stability of the reinforced slope.The optimum design was carried out to treat an expansive soil cut slope in Hubei Province,China,by changing the spacing and length of geogrid reinforcement.Calculation results show that the additional pullout force caused by lateral swelling has a great influence on the anti-pullout stability of geogrids,and the local stability of the reinforced slope will be overestimated if the swelling effect of soil in the free zone is not considered.展开更多
The laser technology has made remarkable progress over the past couple of decades.It is being widely employed in diverse domains,such as holography,space sciences,spectroscopy,medical sciences,micro and power electron...The laser technology has made remarkable progress over the past couple of decades.It is being widely employed in diverse domains,such as holography,space sciences,spectroscopy,medical sciences,micro and power electronics,industrial engineering,and most distinctively,as directed energy military weapons.Owing to their active transmissions,laser systems are similar to microwave radars to some extent;however,unlike conventional radars,the laser operates at very high frequencies thus making it a potent enabler of narrow-beam and high energy aerial deployments,both in offensive and defensive roles.In modern avionics systems,laser target indicators and beam riders are the most common devices that are used to direct the Laser Guided Weapons(LGW)accurately to the ground targets.Additionally,compact size and outstanding angular resolution of laser-based systems motivate their use for drones and unmanned aerial applications.Moreover,the narrow-beam divergence of laser emissions offers a low probability of intercept,making it a suitable contender for secure transmissions and safety-critical operations.Furthermore,the developments in space sciences and laser technology have given synergistic potential outcomes to use laser systems in space operations.This paper comprehensively reviews laser applications and projects for strategic defense actions on the ground or in space.Additionally,a detailed analysis has been done on recent advancements of the laser technology for target indicators and range-finders.It also reviews the advancements in the field of laser communications for surveillance,its earlier state of the art,and ongoing scientific research and advancements in the domain of high energy directed laser weapons that have revolutionized the evolving military battlefield.Besides offering a comprehensive taxonomy,the paper also critically analyzes some of the recent contributions in the associated domains.展开更多
The defence sector is now at an advanced level,catering to the global scenario,and countries also invest heavily in research and development.Countries around the world have spent a lot of money on research and develop...The defence sector is now at an advanced level,catering to the global scenario,and countries also invest heavily in research and development.Countries around the world have spent a lot of money on research and development over the years in order to stay ahead of their competitors.Lightweight materials are critical in defence applications because they allow components to be lighter without sacrificing strength.This review provides an overview of the research related to defence applications.The book provides comprehensive details on current trends in the application of lightweight materials in defence.This review also includes historical and current perspectives on defence technologies.It discusses uses of lightweight materials such as metal matrix composites,polymer composites,ceramic matrix composites,fiber composites in defence sectors Finally,the review paper also emphasizes future military applications of lightweight materials.展开更多
文摘This paper adopts server-side Java programming model: mod e 1- view-cont roller to construct welybased shopping system framework. Using servlets, Java server pages (JSPs) and JavaBeantechnologies, we provide a standard, open, robust and cross-platform architecture. It can guarantee system- independence. Presented framework provides a clean separation of presentation from business logic which meets user's taste by changing user interface frequenctly, and enables more functions to be conventiently added in future.
基金Supported by the National Natural Science Foundation of China through grant No.49790020
文摘CRESDA Application System of CBERS-1 was established in 1999. During the operation of the system for more than two years, about 240 000 scenes of CBERS-1 Level 0 data have been archived and more than 13 000 scenes of Level 2 products have been ordered by end users from different application fields.In this paper, the typical examples of applications in crop yield estimation,calamity alleviation, resources survey and protection, environment monitoring and continuable development, and urban planning are mainly described.
基金Project(2023YFC2907600)supported by the National Key Research and Development Program of ChinaProjects(42277174,42477166)supported by the National Natural Science Foundation of China+1 种基金Project(2024JCCXSB01)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(KFJJ24-01M)supported by the State Key Laboratory of Explosion Science and Safety Protection,Beijing Institute of Technology,China。
文摘Considering the characteristics of deep thick top coal roadway,in which the high ground stress,coal seam with low strength,and a large range of surrounding rock fragmentation,the pressure relief anchor box beam support system with high strength is developed.The high-strength bearing characteristics and coupling yielding support mechanism of this support system are studied by the mechanical tests of composite members and the combined support system.The test results show that under the coupling effect of support members,the peak stress of the box-shaped support beam in the anchor box beam is reduced by 21.9%,and the average deformation is increased by 135.0%.The ultimate bending bearing capacity of the box-shaped support beam is 3.5 times that of traditional channel beam.The effective compressive stress zone applied by the high prestressed cable is expanded by 26.4%.On this basis,the field support comparison test by the anchor channel beam,the anchor I-shaped beam and the anchor box beam are carried out.Compared with those of the previous two,the surrounding rock convergence of the latter is decreased by 41.2%and 22.2%,respectively.The field test verifies the effectiveness of the anchor box beam support system.
文摘【Objectives】Rose(Rosa hybrida L.)is a beautiful and widely cultivated flowering plant around the world whose quality is of great commercial importance.The objective of this study was to investigate the impact of foliar application of calcium nitrate on the quality and postharvest life of two rose varieties(cvs.Samurai,and Jumilia)in a soilless culture system.【Methods】The research used a hydroponic culture method,the roses plants were grown in Hoagland nutrient solution containing 50%less Ca for a total span of 4 months.One month was dedicated to plant acclimatization,and 3 months for spray treatment.Two rose varieties(Rosa hybrida L.),cvs.Samurai and Jumilia plants were used as test materials and planted in pots containing 100%perlite(3-5 mm).After one month of culture,160 mg/kg CaNO3 solution was sprayed,and each treatment corresponded to the first,second,and third harvests,respectively.The plant and flower growth indicators and flower vase life were investigated after each harvesting immediately.【Results】A positive impact of foliar-applied Ca on stem characteristics,pedicel dimensions,corolla size,flower attributes,and vase life was found.Furthermore,a general trend was observed,wherein an increase in the number of harvesting stages led to improved traits.Notably,Jumilia rose consistently exhibited lower values for all studied traits,except for flower vase life,in comparison to the Samurai rose.While there were no significant differences in length values between Samurai and Jumilia roses due to calcium foliar application across the three harvesting stages.Duncan’s grouping revealed a specific effect on Jumilia roses during the third harvest stage.Calcium fertilizer significantly increased photosynthesis rates of of rose leaves in the calcium treatments compared with the control treatment.【Conclusions】Foliar spraying of calcium nitrate is an effective measure to promote the growth of roses and improve the yield,quality and bottle life of fresh cut flowers.
基金西南大学中央高校基本科研业务费项目(SWU-KT22030)重庆市教育委员会科学技术研究项目(KJQN202300205)Deutsche Forschungsgemeinschaft(DFG,German Research Foundation,457444676).
文摘Diamond combines many unique properties,including high stability,strong optical dispersion,excellent mechanical strength,and outstanding thermal conductivity.Its structure,surface groups,and electrical conductivity are also tunable,increasing its functional versatility.These make diamond and its related materials,such as its composites,highly promising for various applications in energy fields.This review summarizes recent advances and key achievements in energy storage and conversion,covering electrochemical energy storage(e.g.,batteries and supercapacitors),electrocatalytic energy conversion(e.g.,CO_(2)and nitrogen reduction reactions),and solar energy conversion(e.g.,photo-(electro)chemical CO_(2)and nitrogen reduction reactions,and solar cells).Current challenges and prospects related to the synthesis of diamond materials and the technologies for their energy applications are outlined and discussed.
文摘Background Zonal application maps are designed to represent field variability using key variables that can be translated into tailored management practices.For cotton,zonal maps for crop growth regulator(CGR)applications under variable-rate(VR)strategies are commonly based exclusively on vegetation indices(VIs)variability.However,VIs often saturate in dense crop vegetation areas,limiting their effectiveness in distinguishing variability in crop growth.This study aimed to compare unsupervised framework(UF)and supervised framework(SUF)approaches for generat-ing zonal application maps for CGR under VR conditions.During 2022-2023 agricultural seasons,an UF was employed to generate zonal maps based on locally collected field data on plant height of cotton,satellite imagery,soil texture,and phenology data.Subsequently,a SUF(based on historical data between 2020-2021 to 2022-2023 agricultural seasons)was developed to predict plant height using remote sensing and phenology data,aiming to replicate same zonal maps but without relying on direct field measurements of plant height.Both approaches were tested in three fields and on two different dates per field.Results The predictive model for plant height of SUF performed well,as indicated by the model metrics.However,when comparing zonal application maps for specific field-date combinations,the predicted plant height exhibited lower variability compared with field measurements.This led to variable compatibility between SUF maps,which utilized the model predictions,and the UF maps,which were based on the real field data.Fields characterized by much pronounced soil texture variability yielded the highest compatibility between the zonal application maps produced by both SUF and UF approaches.This was predominantly due to the greater consistency in estimating plant development patterns within these heterogeneous field environments.While VR application approach can facilitate product savings during the application operation,other key factors must be considered.These include the availability of specialized machinery required for this type of applications,as well as the inherent operational costs associated with applying a single CGR product which differs from the typical uniform rate applications that often integrate multi-ple inputs.Conclusion Predictive modeling shows promise for assisting in the creation of zonal application maps for VR of CGR applications.However,the degree of agreement with the actual variability in crop growth found in the field should be evaluated on a field-by-field basis.The SUF approach,which is based on plant heigh prediction,demonstrated potential for supporting the development of zonal application maps for VR of CGR applications.However,the degree to which this approach aligns itself with the actual variability in crop growth observed in the field may vary,necessi-tating field-by-field evaluation.
基金support by the 11th Five Year Key Project of China’s National Scientific Supporting Plan(Grant No.2006BAB04A03)the Hydraulic Engineering Project from the Water Resources Department of Jiangsu Province(Grant No.2010023)
文摘Based on the characteristics of large flow rate , low head , short annual operation time , and high reliability of the city flood-control pumping stations , a new-type shaft tubular pumping system featuring a shaft suction box and a siphon-type discharge passage with a vacuum breaker as the cutoff device was developed , which possesses such advantages as simple structure , reliable cutoff , and high energy performance.Taking some pumping stations as the case studies , in the light of the specified operation conditions , the hydraulic optimal design of the shaft-type tubular pumping system was determined and the optimized shape of the system was recommended.The performance prediction based on the computational fluid dynamics methodology was determined and the model test verification was conducted.The results show that the predicted data agree with the experimental head and efficiency so that both methods can be used to determine the performance of a real pumping station.Finally , the in-situ measurements of a pumping station during the commissioning period further verified that the shaft-type tubular pumping station with a siphon discharge passage is of higher efficiency , more reliable and stable.
基金Project(2001AA501433) supported by the National High Technology Research and Development Programof China
文摘Application of thermal electrochemical equation to metal-hydride half-cell system was investigated, and the influence of state of charge on the thermal electrochemical performance of hydrogen storage materials was studied. The results show that both the absolute value of the molar enthalpy change and the internal resistance of evolution hydrogen reaction are less than that of absorption hydrogen reaction at the same state of charge. The molar reaction enthalpy change of absorption and evolution of hydride electrode change contrarily with the enhancement of filling degree of hydrogen in hydride electrode. The relation curve of molar reaction enthslpy change to state of charge, both absorption and evolution hydrogen reaction, is close to a constant when the state of charge is 10%- 60%, and during state of charge below 10% or state of charge above 60%, the molar reaction enthalpy change varies sharply. Meanwhile, the internal resistance of electrode reaction has an ascending trend with the enhancement on filling degree of hydrogen in hydride electrode in both absorption and evolution hydrogen reaction.
文摘In this paper the application of a cleaning system which was made up of a centrifugal fan with double channel and one sieve to 4LZ-3.5 combine was introduced. This cleaning system with double channel compared with the traditional air-sieve cleaning system of combines may omit one two sieves and simplify the transmission mechanism. It is also compared with the present cleaning system with double channel applied to some combines, such as the Commandor 112CS/ 228CS combines of Claas Corporation in Germany and the MAXIMIZERTMombincs of John Deerc company in U.S.A. It may omit one sieve and the preclcaner and simlify the transmission mechanism. The measuring results indicated that the cleaning ratio of wheat grain is 99.1% and the cleaning loss ratio of wheat is 0.17% when the feed rate is 4.01 kg/ s.
基金Supported by Remote Sensing Support for Offshore Ocean Environment and Polar Sea Ice Early Warning Services(102121201550000009004)。
文摘This paper presents the networking observation capabilities of Chinese ocean satellites and their diverse applications in ocean disaster prevention,ecological monitoring,and resource development.Since the inaugural launch in 2002,China has achieved substantial advancements in ocean satellite technology,forming an observation system composed of the HY-1,HY-2,and HY-3 series satellites.These satellites are integral to global ocean environmental monitoring due to their high resolution,extensive coverage,and frequent observations.Looking forward,China aims to further enhance and expand its ocean satellite capabilities through ongoing projects to support global environmental protection and sustainable development.
文摘Manuel C.Molles Jr.所著的Ecology:Concepts and Applications(《生态学:概念与应用》)在教材与网络资源的建设方面进行了有益的尝试,其主教材及辅助教学资源的设计理念值得借鉴。主教材从1999年到2008年出版了4版,主教材内容及版本更新快,力求及时反映学科前沿水平的新技术、新知识;正文内容和版式编排设计以读者为本,注重为学生服务;网上辅助教学资源围绕主教材的系列产品进行整体设计,体现利教利学的建设理念,既为教师教学提供帮助和指导,也重视给予学生自我发挥的空间,网站展示条理清晰,内容布局规范,内容介绍注重以读者为中心,满足不同客户的需求。
文摘Electrospinning technology has emerged as a promising method for fabricating flexible lithium-ion batter-ies(FLIBs)due to its ability to create materials with desir-able properties for energy storage applications.FLIBs,which are foldable and have high energy densities,are be-coming increasingly important as power sources for wear-able devices,flexible electronics,and mobile energy applica-tions.Carbon materials,especially carbon nanofibers,are pivotal in improving the performance of FLIBs by increas-ing electrical conductivity,chemical stability,and surface area,as well as reducing costs.These materials also play a significant role in establishing conducting networks and im-proving structural integrity,which are essential for extend-ing the cycle life and enhancing the safety of the batteries.This review considers the role of electrospinning in the fabrication of critical FLIB components,with a particular emphasis on the integration of carbon materials.It explores strategies to optimize FLIB performance by fine-tuning the electrospinning para-meters,such as electric field strength,spinning rate,solution concentration,and carbonization process.Precise control over fiber properties is crucial for enhancing battery reliability and stability during folding and bending.It also highlights the latest research findings in carbon-based electrode materials,high-performance electrolytes,and separator structures,discussing the practical challenges and opportunities these materials present.It underscores the significant impact of carbon materials on the evolution of FLIBs and their potential to shape future energy storage technologies.
文摘Carbon materials are a key component in energy storage and conversion devices and their microstructure plays a crucial role in determining device performance.However,traditional carbon materials are unable to meet the requirements for applications in emerging fields such as renewable energy and electric vehicles due to limitations including a disordered structure and uncontrolled defects.With an aim of realizing devisable structures,adjustable functions,and performance breakthroughs,superstructured carbons is proposed and represent a category of carbon-based materials,characterized by precisely-built pores,networks,and interfaces.Superstructured carbons can overcome the limitations of traditional carbon materials and improve the performance of energy storage and conversion devices.We review the structure-activity relationships of superstructured carbons and recent research advances from three aspects including a precisely customized pore structure,a dense carbon network framework,and a multi-component highly coupled interface between the different components.Finally,we provide an outlook on the future development of and practical challenges in energy storage and conversion devices.
文摘This study investigates the potential of metal additives in acrylonitrile butadiene styrene(ABS)polymer fuel to enhance hybrid rocket motor(HRM)performance through computational analysis,Chemical Equilibrium with Applications(CEA),software.ABS was selected as the base fuel due to its thermoplastic nature,which allows for the creation of complex fuel geometries through 3D printing,offering significant flexibility in fuel design.Hybrid rockets,which combine a solid fuel with a liquid oxidiser,offer advantages in terms of operational simplicity and safety.However,conventional polymer fuels often exhibit low regression rates and suboptimal combustion efficiencies.In this research,we evaluated a range of metal additives-aluminium(Al),boron(B),nickel(Ni),copper(Cu),and iron(Fe)-at chamber pressures ranging from 1 to 30 bar and oxidiser-to-fuel(O/F)ratios between 1.1 and 12,resulting in 1800 unique test conditions.The main performance parameters used to assess each formulation were characteristic velocity(C^(*))and adiabatic flame temperature.The results revealed that each test produced a different optimum O/F ratio,with most ratios falling between 4 and 6.The highest performance was achieved at a chamber pressure of 30 bar across all formulations.Among the additives,Al and B demonstrated significant potential for improved combustion performance with increasing metal loadings.In contrast,Fe,Cu,and Ni reached optimal performance at a minimum loading of 1%.Future work includes investigating B-Al metal composites as additives into the ABS base polymer fuel,and doing experimental validation tests where the metallised ABS polymer fuel is 3D printed.
基金Project(51978085)supported by the National Natural Science Foundation of ChinaProject(201808430102)supported by the China Scholarship Council+1 种基金Project(JTG-201507)supported by the Highway Industry Standard Compilation Project of Ministry of Transportation,ChinaProject(kfj180102)supported by the Open Fund of Changsha University of Science&Technology,China。
文摘The traditional stability analysis method of geogrid reinforced slopes does not consider the effect of lateral swelling,so it is not applicable to reinforced expansive soil slopes.This paper reports a new stability analysis method for geogrid reinforced expansive soil slopes.The additional pullout force of the free zone due to the lateral swelling and the anti-pullout safety factor of each geogrid layer were obtained by ensuring the overall stability of the reinforced slope.The optimum design was carried out to treat an expansive soil cut slope in Hubei Province,China,by changing the spacing and length of geogrid reinforcement.Calculation results show that the additional pullout force caused by lateral swelling has a great influence on the anti-pullout stability of geogrids,and the local stability of the reinforced slope will be overestimated if the swelling effect of soil in the free zone is not considered.
文摘The laser technology has made remarkable progress over the past couple of decades.It is being widely employed in diverse domains,such as holography,space sciences,spectroscopy,medical sciences,micro and power electronics,industrial engineering,and most distinctively,as directed energy military weapons.Owing to their active transmissions,laser systems are similar to microwave radars to some extent;however,unlike conventional radars,the laser operates at very high frequencies thus making it a potent enabler of narrow-beam and high energy aerial deployments,both in offensive and defensive roles.In modern avionics systems,laser target indicators and beam riders are the most common devices that are used to direct the Laser Guided Weapons(LGW)accurately to the ground targets.Additionally,compact size and outstanding angular resolution of laser-based systems motivate their use for drones and unmanned aerial applications.Moreover,the narrow-beam divergence of laser emissions offers a low probability of intercept,making it a suitable contender for secure transmissions and safety-critical operations.Furthermore,the developments in space sciences and laser technology have given synergistic potential outcomes to use laser systems in space operations.This paper comprehensively reviews laser applications and projects for strategic defense actions on the ground or in space.Additionally,a detailed analysis has been done on recent advancements of the laser technology for target indicators and range-finders.It also reviews the advancements in the field of laser communications for surveillance,its earlier state of the art,and ongoing scientific research and advancements in the domain of high energy directed laser weapons that have revolutionized the evolving military battlefield.Besides offering a comprehensive taxonomy,the paper also critically analyzes some of the recent contributions in the associated domains.
文摘The defence sector is now at an advanced level,catering to the global scenario,and countries also invest heavily in research and development.Countries around the world have spent a lot of money on research and development over the years in order to stay ahead of their competitors.Lightweight materials are critical in defence applications because they allow components to be lighter without sacrificing strength.This review provides an overview of the research related to defence applications.The book provides comprehensive details on current trends in the application of lightweight materials in defence.This review also includes historical and current perspectives on defence technologies.It discusses uses of lightweight materials such as metal matrix composites,polymer composites,ceramic matrix composites,fiber composites in defence sectors Finally,the review paper also emphasizes future military applications of lightweight materials.
