In this paper, the NU308 bearing rings were subjected to strengthen grinding treatment (SGT) at ambient temperature. And the running reliabilities of specimens that subjected to SGT and conventional treatment (CT) wer...In this paper, the NU308 bearing rings were subjected to strengthen grinding treatment (SGT) at ambient temperature. And the running reliabilities of specimens that subjected to SGT and conventional treatment (CT) were respectively investigated by testing dynamic properties including the running temperature, vibrations, and surface burning. Moreover, the residual stress, microtopography, and microstructures on the cross-section were respectively tested with residual stress analyzer and field-emission scanning electron microscopy. The results showed that the running reliabilities of the specimen after SGT had been significantly improved with the reduction of running temperature, vibration, and surface burning. Further study showed that the specimen’s surface was filled with disordered micropores after SGT compared to the regular strip texture on the CT specimen’s surface, and the maximum residual compressive stress induced by SGT was about −900 MPa. Moreover, the thickness of the residual compressive stress layer was over 180 µm, while the thickness of severe plastic deformation layer was about 50 µm.展开更多
<span style="font-family:Verdana;">Venturi tubes are widely used in manufacture and chemical industry and at</span><span style="font-family:Verdana;"><span style="font-fam...<span style="font-family:Verdana;">Venturi tubes are widely used in manufacture and chemical industry and at</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">t</span></span><span style="font-family:Verdana;">ract broad attention. To improve the transmission efficiency, the optimization of Venturi tube has been carried out, the transport substances involved in either liquid, solid, gas or two of them. The Venturi tubes that used for conveying of three-phase flow, which is consisted of solid, liquid and gas, are poorly investigated. In this paper, a Venturi tube employed in one surface treatment equipment was proposed. The velocity and pressure distribution in the flow field of Venturi tube with different key geometric parameters including diameter ratio, convergence angle and diffuser angle have been studied. One optimal solution has been selected. The negative pressure of suction port can reach a value as high as -</span><span style="font-family:Verdana;">1550 Pa to -</span><span style="font-family:Verdana;">1600 Pa. Such negative pressure offers the opportunities for transporting mixed abrasive.</span>展开更多
Considering the high-quality requirements related to agricultural crop production,the collaborative operation and application influence of sprinkler drip irrigation is an important issue in precision agriculture.The o...Considering the high-quality requirements related to agricultural crop production,the collaborative operation and application influence of sprinkler drip irrigation is an important issue in precision agriculture.The objective of this review is to give a comprehensive demonstration focusing on the subject of collaborative operation and application influence of sprinkler drip irrigation,by using a set of comparative analysis and literature bibliometric maps,therefore the sprinkler drip irrigation quality considering actual influential factors could be determined and analyzed.This review establishes on a broad spectrum of agricultural drip irrigation performance,throughout its whole procedure of collaborative monitoring,irrigation scheduling,application efficiency,and environmental influence,covering such aspects as soil physicochemical quality,irrigation scheduling,water resource redistribution,crop productivity,tillage management,climate adaptation,and environmental monitoring,etc.This review indicates that,the irrigation efficiency and drip infiltration quality of soil field can be planned precisely and allocated reasonably by sprinkler drip irrigation,which has extraordinary infiltration capability and enables much better performance,than that of other ordinary irrigation approaches in accuracy,stability,regularity,and efficiency.Thereafter,the investigation on the collaborative operation and application influence of sprinkler drip irrigation can be used to ensure the infiltration uniformity of moisture distribution,and then the high-quality requirements of practical irrigation performance can be met,too.This systematic review facilitates the productive soil-moisture-environment management for precision irrigation and agricultural production.展开更多
Precision irrigation,defined as accurate and appropriate agricultural techniques characterized by optimal management and best collaboration of various irrigation factors,attracts great attention and obtains wide emplo...Precision irrigation,defined as accurate and appropriate agricultural techniques characterized by optimal management and best collaboration of various irrigation factors,attracts great attention and obtains wide employments in different irrigation conditions or cultivation processes.Moreover,it becomes well-established in major areas of agricultural researches and across the broad spectrum of agricultural techniques especially in specific sectors of scientific frontiers,including soil quality,irrigation scheduling,water resource distribution,crop productivity,tillage management,climate adaptation,and environment monitoring,etc.This paper reviews the research developments and integrated applications of precision irrigation in typical domains of mechanism and performance,covering key aspects such as process optimization,schedule modelling,and effectiveness evaluation,indicating that advanced irrigation optimization methods support higher productivity of crop field and better environmental conditions of soil;Current schedule modelling techniques provide a set of instructive demonstrations and heuristic descriptions for the working principles of precision irrigation and the quantitative assessments of irrigation productivity;The novel investigation on effectiveness evaluation is extremely significant to obtain higher infiltration efficiency,simultaneously to achieve the optimized irrigation qualities for water balance condition,soil water redistribution,and soil moisture uniformity so that the effectiveness quality of irrigation infiltration could be improved remarkably.It is concluded that precision irrigation owns an outstanding collaborating capability and possesses much better working advancement in typical calibration indexes of cultivation accuracy and infiltration efficiency,meanwhile,a high agreement between the predicted and actual irrigation effectiveness could be expected.This novel irrigation review concentrating on the conceptual and systematic progress should be promoted constructively to improve the quality uniformity for precision irrigation and its constructive influences in different applications,and to facilitate the integrated management of agricultural production by higher irrigation efficiency consequently.展开更多
In order to improve sprinkler irrigation quality and promote actual irrigation efficiency,the influence analysis of sprinkler irrigation effectiveness(SIE)using ANFIS(Adaptive Neural Fuzzy Inference System)was impleme...In order to improve sprinkler irrigation quality and promote actual irrigation efficiency,the influence analysis of sprinkler irrigation effectiveness(SIE)using ANFIS(Adaptive Neural Fuzzy Inference System)was implemented to balance moisture infiltration and water redistribution in soil field.Firstly,using a detailed description of governing equations proposed for sprinkler irrigation flow,the theoretical foundation and mathematical model of irrigation effectiveness can be established;Secondly,based on a complete preparation of experimental irrigation conditions,a series of calibration indexes quantifying SIE for sprinkler irrigation quality and infiltration efficiency were proposed;Then thirdly,a novel ANFIS system was designed and introduced to evaluate these key effectiveness indexes in actual working operations,so that a series of detailed influence analysis and comprehensive infiltration assessment focusing on sprinkler irrigation effectiveness could be achieved afterwards,which result to the realization of better infiltration equilibrium and higher water redistribution efficiency in actual irrigation test.Therefore,the qualification of sprinkler irrigation effectiveness was achieved,and in addition,the moisture infiltration improvement and soil moisture uniformity were facilitated also in return.展开更多
When evaluating the performance of distributed software-defined network(SDN)controller architecture in data center networks,the required number of controllers for a given network topology and their location are major ...When evaluating the performance of distributed software-defined network(SDN)controller architecture in data center networks,the required number of controllers for a given network topology and their location are major issues of interest.To address these issues,this study proposes the adaptively adjusting and mapping controllers(AAMcon)to design a stateful data plane.We use the complex network community theory to select a key switch to place the controller which is closer to switches it controls in a subnet.A physically distributed but logically centralized controller pool is built based on the network function virtualization(NFV).And then we propose a fast start/overload avoid algorithm to adaptively adjust the number of controllers according to the demand.We performed an analysis for AAMcon to find the optimal distance between the switch and controller.Finally,experiments show the following results.(1)For the number of controllers,AAMcon can greatly follow the demand;for the placement location of controller,controller can respond to the request of switch with the least distance to minimize the delay between the switch and it.(2)For failure tolerance,AAMcon shows good robustness.(3)AAMcon requires less delay to the network with more significant community structure.In fact,there is an inverse relationship between the community modularity and average distance between the switch and controller,i.e.,the average delay decreases when the community modularity increases.(4)AAMcon can achieve the load balance between the controllers.(5)Compared to DCP-GK and k-critical,AAMcon shows good performance.展开更多
文摘In this paper, the NU308 bearing rings were subjected to strengthen grinding treatment (SGT) at ambient temperature. And the running reliabilities of specimens that subjected to SGT and conventional treatment (CT) were respectively investigated by testing dynamic properties including the running temperature, vibrations, and surface burning. Moreover, the residual stress, microtopography, and microstructures on the cross-section were respectively tested with residual stress analyzer and field-emission scanning electron microscopy. The results showed that the running reliabilities of the specimen after SGT had been significantly improved with the reduction of running temperature, vibration, and surface burning. Further study showed that the specimen’s surface was filled with disordered micropores after SGT compared to the regular strip texture on the CT specimen’s surface, and the maximum residual compressive stress induced by SGT was about −900 MPa. Moreover, the thickness of the residual compressive stress layer was over 180 µm, while the thickness of severe plastic deformation layer was about 50 µm.
文摘<span style="font-family:Verdana;">Venturi tubes are widely used in manufacture and chemical industry and at</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">t</span></span><span style="font-family:Verdana;">ract broad attention. To improve the transmission efficiency, the optimization of Venturi tube has been carried out, the transport substances involved in either liquid, solid, gas or two of them. The Venturi tubes that used for conveying of three-phase flow, which is consisted of solid, liquid and gas, are poorly investigated. In this paper, a Venturi tube employed in one surface treatment equipment was proposed. The velocity and pressure distribution in the flow field of Venturi tube with different key geometric parameters including diameter ratio, convergence angle and diffuser angle have been studied. One optimal solution has been selected. The negative pressure of suction port can reach a value as high as -</span><span style="font-family:Verdana;">1550 Pa to -</span><span style="font-family:Verdana;">1600 Pa. Such negative pressure offers the opportunities for transporting mixed abrasive.</span>
基金supported by the National Key Research and Development Program of China(Grant No.2023YFB100140)National Natural Science Foundation of China(Grant No.51975136)+4 种基金Natural Science Foundation of Guangdong Province(Grant No.2023A1515011723)Industry-University-research Collaborative Innovation Base of Ministry of Education(Grant No.230703950183536,220903950010408)Special Research Projects in the Key Fields of Guangdong Higher Educational Universities(Grant No.2023ZDZX3016,2019KZDZX1009)Tertiary Education Scientific research project of Guangzhou Municipal Education Bureau(Grant No.202235139)Guangzhou University Research Project(Grant No.YJ2023034,YJ2021002).
文摘Considering the high-quality requirements related to agricultural crop production,the collaborative operation and application influence of sprinkler drip irrigation is an important issue in precision agriculture.The objective of this review is to give a comprehensive demonstration focusing on the subject of collaborative operation and application influence of sprinkler drip irrigation,by using a set of comparative analysis and literature bibliometric maps,therefore the sprinkler drip irrigation quality considering actual influential factors could be determined and analyzed.This review establishes on a broad spectrum of agricultural drip irrigation performance,throughout its whole procedure of collaborative monitoring,irrigation scheduling,application efficiency,and environmental influence,covering such aspects as soil physicochemical quality,irrigation scheduling,water resource redistribution,crop productivity,tillage management,climate adaptation,and environmental monitoring,etc.This review indicates that,the irrigation efficiency and drip infiltration quality of soil field can be planned precisely and allocated reasonably by sprinkler drip irrigation,which has extraordinary infiltration capability and enables much better performance,than that of other ordinary irrigation approaches in accuracy,stability,regularity,and efficiency.Thereafter,the investigation on the collaborative operation and application influence of sprinkler drip irrigation can be used to ensure the infiltration uniformity of moisture distribution,and then the high-quality requirements of practical irrigation performance can be met,too.This systematic review facilitates the productive soil-moisture-environment management for precision irrigation and agricultural production.
基金The authors acknowledge the funding received from the following science foundations:National Natural Science Foundation of China(51975136,51575116,U1601204,52075109)National Key Research and Development Program of China(2018YFB2000501)+7 种基金China National Spark Program(2015GA780065)the Science and Technology Innovative Research Team Program in Higher Educational Universities of Guangdong Province(2017KCXTD025)the Innovative Academic Team Project of Guangzhou Education System(1201610013)the Special Research Projects in the Key Fields of Guangdong Higher Educational Universities(2019KZDZX1009)the Science and Technology Research Project of Guangdong Province(2017A010102014,2016A010102022)the Science and Technology Research Project of Guangzhou(201707010293)and Guangzhou University Research Project(YJ2021002)which are all appreciated for supporting this work.The authors also want to thank the editors for their hard work and the referees for their kind comments and valuable suggestions to improve this paper.
文摘Precision irrigation,defined as accurate and appropriate agricultural techniques characterized by optimal management and best collaboration of various irrigation factors,attracts great attention and obtains wide employments in different irrigation conditions or cultivation processes.Moreover,it becomes well-established in major areas of agricultural researches and across the broad spectrum of agricultural techniques especially in specific sectors of scientific frontiers,including soil quality,irrigation scheduling,water resource distribution,crop productivity,tillage management,climate adaptation,and environment monitoring,etc.This paper reviews the research developments and integrated applications of precision irrigation in typical domains of mechanism and performance,covering key aspects such as process optimization,schedule modelling,and effectiveness evaluation,indicating that advanced irrigation optimization methods support higher productivity of crop field and better environmental conditions of soil;Current schedule modelling techniques provide a set of instructive demonstrations and heuristic descriptions for the working principles of precision irrigation and the quantitative assessments of irrigation productivity;The novel investigation on effectiveness evaluation is extremely significant to obtain higher infiltration efficiency,simultaneously to achieve the optimized irrigation qualities for water balance condition,soil water redistribution,and soil moisture uniformity so that the effectiveness quality of irrigation infiltration could be improved remarkably.It is concluded that precision irrigation owns an outstanding collaborating capability and possesses much better working advancement in typical calibration indexes of cultivation accuracy and infiltration efficiency,meanwhile,a high agreement between the predicted and actual irrigation effectiveness could be expected.This novel irrigation review concentrating on the conceptual and systematic progress should be promoted constructively to improve the quality uniformity for precision irrigation and its constructive influences in different applications,and to facilitate the integrated management of agricultural production by higher irrigation efficiency consequently.
基金the funding of following science foundations:National Natural Science Foundation of China(51975136,51575116,U1601204)China National Spark Program(2015GA780065)+6 种基金The Science and Technology Innovative Research Team Program in Higher Educational Universities of Guangdong Province(2017KCXTD025)The Innovative Academic Team Project of Guangzhou Education System(1201610013)The Science and Technology Planning Project of Guangdong Province(2017A010102014,2016A010102022)The Science and Technology Planning Project of Guangzhou Municipal Government(201707010293)The Water Resource Science and Technology Program of Guangdong Province of China(2012-11)Guangzhou University's 2017 training program for young top-notch personnels(BJ201701)The Postgraduate Education Innovation Program of Guangdong Province(2016SQXX14,2016XSLT24)。
文摘In order to improve sprinkler irrigation quality and promote actual irrigation efficiency,the influence analysis of sprinkler irrigation effectiveness(SIE)using ANFIS(Adaptive Neural Fuzzy Inference System)was implemented to balance moisture infiltration and water redistribution in soil field.Firstly,using a detailed description of governing equations proposed for sprinkler irrigation flow,the theoretical foundation and mathematical model of irrigation effectiveness can be established;Secondly,based on a complete preparation of experimental irrigation conditions,a series of calibration indexes quantifying SIE for sprinkler irrigation quality and infiltration efficiency were proposed;Then thirdly,a novel ANFIS system was designed and introduced to evaluate these key effectiveness indexes in actual working operations,so that a series of detailed influence analysis and comprehensive infiltration assessment focusing on sprinkler irrigation effectiveness could be achieved afterwards,which result to the realization of better infiltration equilibrium and higher water redistribution efficiency in actual irrigation test.Therefore,the qualification of sprinkler irrigation effectiveness was achieved,and in addition,the moisture infiltration improvement and soil moisture uniformity were facilitated also in return.
文摘When evaluating the performance of distributed software-defined network(SDN)controller architecture in data center networks,the required number of controllers for a given network topology and their location are major issues of interest.To address these issues,this study proposes the adaptively adjusting and mapping controllers(AAMcon)to design a stateful data plane.We use the complex network community theory to select a key switch to place the controller which is closer to switches it controls in a subnet.A physically distributed but logically centralized controller pool is built based on the network function virtualization(NFV).And then we propose a fast start/overload avoid algorithm to adaptively adjust the number of controllers according to the demand.We performed an analysis for AAMcon to find the optimal distance between the switch and controller.Finally,experiments show the following results.(1)For the number of controllers,AAMcon can greatly follow the demand;for the placement location of controller,controller can respond to the request of switch with the least distance to minimize the delay between the switch and it.(2)For failure tolerance,AAMcon shows good robustness.(3)AAMcon requires less delay to the network with more significant community structure.In fact,there is an inverse relationship between the community modularity and average distance between the switch and controller,i.e.,the average delay decreases when the community modularity increases.(4)AAMcon can achieve the load balance between the controllers.(5)Compared to DCP-GK and k-critical,AAMcon shows good performance.
