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
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
To Meet the requirements of multi-sensor data fusion in diagnosis for complex equipment systems,a novel, fuzzy similarity-based data fusion algorithm is given. Based on fuzzy set theory, it calculates the fuzzy simila...To Meet the requirements of multi-sensor data fusion in diagnosis for complex equipment systems,a novel, fuzzy similarity-based data fusion algorithm is given. Based on fuzzy set theory, it calculates the fuzzy similarity among a certain sensor's measurement values and the multiple sensor's objective prediction values to determine the importance weigh of each sensor,and realizes the multi-sensor diagnosis parameter data fusion.According to the principle, its application software is also designed. The applied example proves that the algorithm can give priority to the high-stability and high -reliability sensors and it is laconic ,feasible and efficient to real-time circumstance measure and data processing in engine diagnosis.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
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
Based on S-rough sets（singular rough sets）, this paper presents function S-rough sets （function singular rough sets）and its mathematical structures and features. Function S-rough sets has two forms： function one ...Based on S-rough sets（singular rough sets）, this paper presents function S-rough sets （function singular rough sets）and its mathematical structures and features. Function S-rough sets has two forms： function one direction S-rough sets （function one direction singular rough sets） and function two direction S-rough sets （function two direction singular rough sets）. This paper advances the relationship theorem of function S-rough sets and S-rough sets. Function S-rough sets is the general form of S-rough sets, and S-rough sets is the special ease of function S-rough sets. In this paper, applications of function S-rough sets in rough law mining-discovery of system are given. Function S-rough sets is a new research direction of rough sets and rough system.展开更多
The network reliability is difficult to be evaluated because of the complex relationship among the network components.It can be quite different for different users running different applications on the same network.Th...The network reliability is difficult to be evaluated because of the complex relationship among the network components.It can be quite different for different users running different applications on the same network.This paper proposes a new concept and a model of application reliability.Different from the existing models that ignores the effects of applications,the proposed application reliability model considers the effects of different applications on the network performance and different types of network faults and makes the analysis of network components relationship possible.This paper also provides a method to evaluate the application reliability when the data flow satisfies Markov properties.Finally,a case study is presented to illustrate the proposed network reliability model and the analysis method.展开更多
Ajax is really several technologies,each flourishing in its own right,coming together in powerful new ways,which consists of HTML,JavaScript^(TM)technology,DHTML,and DOM,is an outstanding approach that helps to transf...Ajax is really several technologies,each flourishing in its own right,coming together in powerful new ways,which consists of HTML,JavaScript^(TM)technology,DHTML,and DOM,is an outstanding approach that helps to transform clunky Web interfaces into interactive Ajax applications.After the definition to Ajax,how to make asynchronous requests with JavaScript and Ajax was introduced.At the end,advanced requests and responses in Ajax were put forward.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
By two years （2007-2008） located fertilizer experiment, the effect of long-term combined application of organic and inorganic fertilizers on black soil fertility and crop yield was investigated in Shuangcheng City, ...By two years （2007-2008） located fertilizer experiment, the effect of long-term combined application of organic and inorganic fertilizers on black soil fertility and crop yield was investigated in Shuangcheng City, Heilongjiang Province. The results showed that the combined application of organic and inorganic fertilizers could increase the organinc matter, alkaline nitrogen, available phosphorus and available potassium. At the same time, the increasing application of organic fertilizer could reduce the soil bulk density and improve the field moisture capacity. Field moisture capacity and organic matter of the combined application of high quantities of organic manure and inorganic fertilizers AtB5 treatment increased the fhstest, organic matter increased by 3.33 g. kg and field moisture capacity increased by 11.25% than the beginning of the experiment. Under the same fertilization, the combined application of organic and inorganic fertilizers＇ increasing production range was higher than the single chemical fertilizers＇ which was from 0.8% to 9.4%. The results showed that the combined application of organic and inorganic fertilizers could increase the nutrient contents of soil and also was the highest productivity contribution to black soil fertility. It was the best fertilization structure of increasing productivity level and improving the soil fertility.展开更多
The pheno menon of static electricity is unpredictable,particulariy when an aircraft flying at high altitude that causes the accumulation of static charges beyond a threshold value leading to the failure of its parts ...The pheno menon of static electricity is unpredictable,particulariy when an aircraft flying at high altitude that causes the accumulation of static charges beyond a threshold value leading to the failure of its parts and systems including severe explosion and radio communication failure.The accumulation of static charges on aircraft is generated by the virtue of interaction between the outer surface of aircraft and the external environmental attributes encompasses air particles,ice,hail,dust,volcanic ash in addition to its triboelectric charging.In the recent years,advanced polymer-based composites or nanocomposites are preferred structural constituents for aircrafts due to their light weight and comparable mechanical properties,but such composite systems do not render low impedance path for charge flow and are subsequently vulnerable to effect of lightning strike and precipitation static.In this context,it is essential to develop conductive composite systems from non-co nductive polymer natrix by nano fillerembodime nts.The advent of carbon-based nanocomposite/nano materials have adequately addressed such issues related to the nonco nductive polymer matrix and further turned into an avant-garde genre of materials.The current review envisioned to illustrate the detailed exploitation of various polymer nanocomposites in addition to especially mentioned epoxy composites based on carbon fillers like carbon black,carbon nanotube(single walled carbon nanotube and multi walled carbon nanotube) and graphene the development of antistatic application in aircra ft in addition to the static charge phenomenon and condition for its prevalence in avionic systems.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
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
We reported the fabrication of highly porous graphene/TiO2 composite nanofibers in the form of a nonwoven mat by electrospinning followed by calcination in air at 450°C.The graphene can uniformly disperse in high...We reported the fabrication of highly porous graphene/TiO2 composite nanofibers in the form of a nonwoven mat by electrospinning followed by calcination in air at 450°C.The graphene can uniformly disperse in highly porous TiO2 nanofibers.The highly porous graphene/TiO2 composite nanofibers exhibited excellent catalytic activities.The new method for producing graphene/TiO2 composite nanofibers is versatile and can be extended to fabricate various types of metal oxide and graphene nanocomposites.展开更多
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To Meet the requirements of multi-sensor data fusion in diagnosis for complex equipment systems,a novel, fuzzy similarity-based data fusion algorithm is given. Based on fuzzy set theory, it calculates the fuzzy similarity among a certain sensor's measurement values and the multiple sensor's objective prediction values to determine the importance weigh of each sensor,and realizes the multi-sensor diagnosis parameter data fusion.According to the principle, its application software is also designed. The applied example proves that the algorithm can give priority to the high-stability and high -reliability sensors and it is laconic ,feasible and efficient to real-time circumstance measure and data processing in engine diagnosis.
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。
基金This project was surpported by the Natural Science Foundation of Shandong Province of China (Y2004A94)
文摘Based on S-rough sets（singular rough sets）, this paper presents function S-rough sets （function singular rough sets）and its mathematical structures and features. Function S-rough sets has two forms： function one direction S-rough sets （function one direction singular rough sets） and function two direction S-rough sets （function two direction singular rough sets）. This paper advances the relationship theorem of function S-rough sets and S-rough sets. Function S-rough sets is the general form of S-rough sets, and S-rough sets is the special ease of function S-rough sets. In this paper, applications of function S-rough sets in rough law mining-discovery of system are given. Function S-rough sets is a new research direction of rough sets and rough system.
基金supported by the Beijing Natural Science Foundation(4113074)
文摘The network reliability is difficult to be evaluated because of the complex relationship among the network components.It can be quite different for different users running different applications on the same network.This paper proposes a new concept and a model of application reliability.Different from the existing models that ignores the effects of applications,the proposed application reliability model considers the effects of different applications on the network performance and different types of network faults and makes the analysis of network components relationship possible.This paper also provides a method to evaluate the application reliability when the data flow satisfies Markov properties.Finally,a case study is presented to illustrate the proposed network reliability model and the analysis method.
文摘Ajax is really several technologies,each flourishing in its own right,coming together in powerful new ways,which consists of HTML,JavaScript^(TM)technology,DHTML,and DOM,is an outstanding approach that helps to transform clunky Web interfaces into interactive Ajax applications.After the definition to Ajax,how to make asynchronous requests with JavaScript and Ajax was introduced.At the end,advanced requests and responses in Ajax were put forward.
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.
基金Supported by Black Soil Conservation Tillage and Oriented Cultivation Technology Research (GB06B107-1)Innovation Fund of Northeast Agricultural University (CXP7003-3-3)+1 种基金Northeast Agricultural University and the Scientific Research Fund of Heilongjiang Province to Black CollegesUniversities Cold Key Laboratory of Utilization and Protection of Open-funded Projects (GXS08-5)
文摘By two years （2007-2008） located fertilizer experiment, the effect of long-term combined application of organic and inorganic fertilizers on black soil fertility and crop yield was investigated in Shuangcheng City, Heilongjiang Province. The results showed that the combined application of organic and inorganic fertilizers could increase the organinc matter, alkaline nitrogen, available phosphorus and available potassium. At the same time, the increasing application of organic fertilizer could reduce the soil bulk density and improve the field moisture capacity. Field moisture capacity and organic matter of the combined application of high quantities of organic manure and inorganic fertilizers AtB5 treatment increased the fhstest, organic matter increased by 3.33 g. kg and field moisture capacity increased by 11.25% than the beginning of the experiment. Under the same fertilization, the combined application of organic and inorganic fertilizers＇ increasing production range was higher than the single chemical fertilizers＇ which was from 0.8% to 9.4%. The results showed that the combined application of organic and inorganic fertilizers could increase the nutrient contents of soil and also was the highest productivity contribution to black soil fertility. It was the best fertilization structure of increasing productivity level and improving the soil fertility.
文摘The pheno menon of static electricity is unpredictable,particulariy when an aircraft flying at high altitude that causes the accumulation of static charges beyond a threshold value leading to the failure of its parts and systems including severe explosion and radio communication failure.The accumulation of static charges on aircraft is generated by the virtue of interaction between the outer surface of aircraft and the external environmental attributes encompasses air particles,ice,hail,dust,volcanic ash in addition to its triboelectric charging.In the recent years,advanced polymer-based composites or nanocomposites are preferred structural constituents for aircrafts due to their light weight and comparable mechanical properties,but such composite systems do not render low impedance path for charge flow and are subsequently vulnerable to effect of lightning strike and precipitation static.In this context,it is essential to develop conductive composite systems from non-co nductive polymer natrix by nano fillerembodime nts.The advent of carbon-based nanocomposite/nano materials have adequately addressed such issues related to the nonco nductive polymer matrix and further turned into an avant-garde genre of materials.The current review envisioned to illustrate the detailed exploitation of various polymer nanocomposites in addition to especially mentioned epoxy composites based on carbon fillers like carbon black,carbon nanotube(single walled carbon nanotube and multi walled carbon nanotube) and graphene the development of antistatic application in aircra ft in addition to the static charge phenomenon and condition for its prevalence in avionic systems.
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.
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(41271332)supported by the National Natural Science Foundation of China
文摘We reported the fabrication of highly porous graphene/TiO2 composite nanofibers in the form of a nonwoven mat by electrospinning followed by calcination in air at 450°C.The graphene can uniformly disperse in highly porous TiO2 nanofibers.The highly porous graphene/TiO2 composite nanofibers exhibited excellent catalytic activities.The new method for producing graphene/TiO2 composite nanofibers is versatile and can be extended to fabricate various types of metal oxide and graphene nanocomposites.
