In order to predict electromechanical equipments＇ nonlinear and non-stationary condition effectively, max Lyapunov exponent is introduced to the fault trend prediction of large rotating mechanical equipments based on...In order to predict electromechanical equipments＇ nonlinear and non-stationary condition effectively, max Lyapunov exponent is introduced to the fault trend prediction of large rotating mechanical equipments based on chaos theory. The predict method of chaos time series and two methods of proposing f and F are dis- cussed. The arithmetic of max prediction time of chaos time series is provided. Aiming at the key part of large rotating mechanical equipments-bearing, used this prediction method the simulation experiment is carried out. The result shows that this method has excellent performance for condition trend prediction.展开更多
As a starting point in equipment manufacturing,sawing plays an important role in industrial production.Intelligent manufacturing equipment is an important carrier of intelligent manufacturing technologies.Due to the b...As a starting point in equipment manufacturing,sawing plays an important role in industrial production.Intelligent manufacturing equipment is an important carrier of intelligent manufacturing technologies.Due to the backwardness of intelligent technology,the comprehensive performance of sawing equipments in China is obviously different from that in foreign countries.State of the art of advanced sawing equipments is investigated along with the technical bottleneck of sawing machine tool manufacturing,and a new industrial scheme of replacing turning-milling by sawing is described.The key technologies of processing-measuring integrated control,multi-body dynamic optimization,the collaborative sawing network framework,the distributed cloud sawing platform,and the self-adapting service method are analyzed;with consideration of the problems of poor processing control stableness,low single machine intelligence level,no on-line processing data service and active flutter suppression of sawing with wide-width and heavy-load working conditions.Suggested directions for further research,industry implementation,and industry-research collaboration are provided.展开更多
The type of pinion and rack vertical shiplifts has been developed in recent a couple of years in the construction of dams.But the design methods and methodologies have rarely been discussed in literature.The Xiangjiab...The type of pinion and rack vertical shiplifts has been developed in recent a couple of years in the construction of dams.But the design methods and methodologies have rarely been discussed in literature.The Xiangjiaba shiplift is the second shiplift of this type following the Three Gorges shiplift.Being aimed at the technological rationality of the design in synthetically considering security,economy and applicability,this paper presents the research results of some vital issues relating the design of the Xiangjiaba shiplift,including the determination of design water depth of ship chamber based on fluid numeral computation and physical model test,the optimum design of general layout of main equipments and the civil structure of the Xiangjiaba shiplift,the finite element method(FEM) analysis of stress,vibration modes and the buckling of ship chamber,antiseismic research and the design of structures and mechanisms of the shiplift and the optimum design of driving mechanisms.This research provides the theoretical basis for the design of the Xiangjiaba shiplift.The design principles and research methods are valuable for the design of the same type of shiplifts.展开更多
Anti-collision equipments system is developed to solve the collision problems of dam construction equipments, and in the system the determination of equipments＇ space state is important. A uniform moving equation of ...Anti-collision equipments system is developed to solve the collision problems of dam construction equipments, and in the system the determination of equipments＇ space state is important. A uniform moving equation of equipments is established based on the analysis prediction theory and the movements states of equipments. Method of least square was employed to deal with discrete data of equipments＇ space position. Fitting equation matched with the movement equation was presented to do data fitting, and a relevant algorithm was given. Applying the fitting equation, current and future space state of equipments can be accurately predicted. Finally, a case is given and results show that numerical values of data were steady and their precision was high. In LongTan dam construction of the equipments antiollision system, applying this method to forecast the equipments＇ space states and practical running of the system indicate that this method can improve the precision of position, obtain the better forecasting effect and increase the robustness of the system.展开更多
We show a scheme to distribute the entanglement by using three-mode separable Gaussian state prepared with imperfect equipments. The scheme achieves the aim that the entanglement is distributed between two distant par...We show a scheme to distribute the entanglement by using three-mode separable Gaussian state prepared with imperfect equipments. The scheme achieves the aim that the entanglement is distributed between two distant parties with only Gaussian operations and linear optics elements. Moreover, we analyse the logarithmic negativity of the entanglement shared between the two parties when the systems are imperfect and arrive at the conclusion that the logarithmic negativity is asymptotically stable with fluctuations within a certain space range.展开更多
A coupled thermomechanical model is presented to investigate the thermoelastoplastic deformation mechanism of electromechanical equipments under the condition of electrocaloric shock. In the coupling model, differenti...A coupled thermomechanical model is presented to investigate the thermoelastoplastic deformation mechanism of electromechanical equipments under the condition of electrocaloric shock. In the coupling model, differentiating from the previous analyzing viewpoint that looked upon deformation work as additional heat source, temperature-field equation is established by considering the weakening role of deformation work on the intensity of internal heat source; in the process of setting up displacement-field equation, G-derivative of nonlinear functional is introduced into the traditional theory of elastoplastic finite deformation to simplify the expression of structural stiffness; stress-field equation is constructed by using the least square method to improve the stress solution obtained by constitutive equation. The presented model is converted into finite element program to simulate deforming process of 3-D structures with temperature-dependent material properties. As an example, thermal deformation analysis of Shanghai metro cars’ brake resistor is performed and compared with experimental results for illustrating the validity of the presented model.展开更多
Due to the limited management funds and insufficient management efforts,curing barns in traditional tobacco area are outdated and equipments are seriously damaged,which affects the normal operation and increases the m...Due to the limited management funds and insufficient management efforts,curing barns in traditional tobacco area are outdated and equipments are seriously damaged,which affects the normal operation and increases the maintenance cost of bulk curing barns,bringing adverse effects on tobacco leaf curing in the coming year and the sustainable development of tobacco industry in the future.To ensure the normal operation of curing barns and effectively prolong the service life of curing barns during tobacco leaf curing,we should do a good job in the publicity of management and maintenance,improve the system of management and maintenance,raise funds for management and maintenance,inspect facilities and equipments,carefully maintain equipments in curing barn and strictly perform examination and inspection.展开更多
Dyeing & finishing industry makes it possible for textile products to present colorful world on them.When it beautifies human’s life immensely,it also makes great consumption of energy and resources,and causes en...Dyeing & finishing industry makes it possible for textile products to present colorful world on them.When it beautifies human’s life immensely,it also makes great consumption of energy and resources,and causes environmental pollution.展开更多
Pressure equipments in the process industries and the newly developing industries usually have extreme sizes and/or are subjected to extreme operating conditions such as high pressure,blast loading,cryogenic temperatu...Pressure equipments in the process industries and the newly developing industries usually have extreme sizes and/or are subjected to extreme operating conditions such as high pressure,blast loading,cryogenic temperature,elevated temperature,complex corrosion,and so on.In order to understand,research and develop these equipments systematically,a concept of extreme pressure equipments（EPEs） is proposed.The applications and demands of EPEs in petrochemical industry,coal chemical industry,advanced energy,military,space technology,and environment protection are introduced.Basic scientific problems in material,design,inspection, and safety related to EPEs are discussed.Then,take chemical composition,manufacturing process,service duration,and operating conditions for example,main factors which affect material properties of EPEs are analyzed.New design concepts including design based on life cycle,dynamic design and light-weight design are introduced.EPEs with higher efficiency,lower cost and safer performance are in urgent demand in national major projects including ten million ton oil refinery,one million ton ethylene,liquefied natural gas transportation,and nuclear power plant.Thus,further research should be conducted on information acquisition, multi-mechanism damage coupling model,damage inspection,life prediction,online safety monitoring,maintenance strategy,safety pre-warning system,and emergency system.展开更多
The new technology and equipments used in alumina refinery in PINGGUO ALUMINUM COMPANY were introduced. Problems encountered during early period of its operation and improvements to the process and equipments were dis...The new technology and equipments used in alumina refinery in PINGGUO ALUMINUM COMPANY were introduced. Problems encountered during early period of its operation and improvements to the process and equipments were discussed. Current opemtion situation and pedect technical and economical figures were also introduced.展开更多
When subjected to underwater explosion,the anti-shock performance of naval equipment is a key factor affecting the fighting capacity and safety of a war ship. For large-scale naval equipment,it is costly to do the sho...When subjected to underwater explosion,the anti-shock performance of naval equipment is a key factor affecting the fighting capacity and safety of a war ship. For large-scale naval equipment,it is costly to do the shock test for its huge mass and large size. Consequently,the numerical research was carried our to study the shock resistance of the equipment. Taking turbo-charger set for example,its anti-shock performance was studied using software ABAQUS based on the time-domain shock analysis method presented in BV043 /85. According to the analysis results,shock response of typical regions is obtained,some regularity curves are concluded by analyzing the Mises stress of the typical regions,and the weak regions are found out. The study can provide some references on design of turbo-charger set.展开更多
According to the typical engineering samples, a neural net work model with genetic algorithm to optimize weight values is put forward to forecast the productivities and efficiencies of mining faces. By this model we c...According to the typical engineering samples, a neural net work model with genetic algorithm to optimize weight values is put forward to forecast the productivities and efficiencies of mining faces. By this model we can obtain the possible achievements of available equipment combinations under certain geological situations of fully-mechanized coal mining faces. Then theory of fuzzy selection is applied to evaluate the performance of each equipment combination. By detailed empirical analysis, this model integrates the functions of forecasting mining faces' achievements and selecting optimal equipment combination and is helpful to the decision of equipment combination for fully-mechanized coal mining.展开更多
The high summer indoor temperature in agricultural greenhouse is not conducive to crop growth,so it is necessary to cool the greenhouse. In this study,taking the agricultural multi-span greenhouse with strong temperat...The high summer indoor temperature in agricultural greenhouse is not conducive to crop growth,so it is necessary to cool the greenhouse. In this study,taking the agricultural multi-span greenhouse with strong temperature adjustment ability for example,we make an experimental analysis on the temperature changes inside and outside the greenhouse under nine different equipment combinations( fan,skylight,sunshade,sunshade + fan,cooling pad + fan,skylight + fan,sunshade + skylight,sunshade + fan + cooling pad,sunshade + skylight + fan),respectively,and conduct the overall assessment on the measures to cool the summer agricultural greenhouse,in order to provide a reference for selecting a cost-effective cooling method for greenhouse. Tests show that the three treatment modes of fan,sunshade and sunshade + fan almost have no cooling capacity; skylight,sunshade + skylight have cooling capacity,but the effect is slow; cooling pad + fan,sunshade + skylight +fan can reduce the indoor temperature,but the effect is not very good; skylight and fan have good cooling effect; sunshade + fan + cooling pad has obvious cooling effect,which can well meet the cooling needs in the summer greenhouse.展开更多
As the economic level rising,the function and stability of civil aircraft have been greatly improved.However,with the development of science and technology in modern civil aviation transportation,the frequent occurren...As the economic level rising,the function and stability of civil aircraft have been greatly improved.However,with the development of science and technology in modern civil aviation transportation,the frequent occurrence of flight accidents has threatened people’s safety.The main reason is the internal failure of the engine body or the daily maintenance management is incomplete.Therefore,the relevant maintenance management departments should attach great importance to the first core research and management of civil aircraft stability and safety.In view of various equipment problems existing in the operation of civil aircraft,the practical application of data collection mode and maintenance information disclosure mode of modern aircraft maintenance equipment is analyzed.This paper describes some characteristics of aircraft maintenance work,and combined with the main factors affecting the risk of civil aircraft maintenance,giving countermeasures and suggestions to effectively improve the level of civil aircraft maintenance risk management.展开更多
The burgeoning grid technology provides a practical possibility to share Numerical Control （NC） equipment under a Web environment via many-w-many mode which is faced with the difficulty of a driving force for grid w...The burgeoning grid technology provides a practical possibility to share Numerical Control （NC） equipment under a Web environment via many-w-many mode which is faced with the difficulty of a driving force for grid workflow. This paper proposes the novel methodology of coupling constraints to overcome this difficulty. First, the complex constraints and the structure attributes of NC tasks are detailed in the NC equipment grid that illustrates the possibility of forming a grid workflow force by coupling constraints. Second, the principle of driving force by coupling constraints in an NC equipment grid and the relative algorithm are proposed. Finally, the case study of comparative experiment is detailed to demonstrate the efficiency of this novel tactic.展开更多
Based on inspection data,the authors analyze and summarize the main types and distribution characteristics of tunnel structural defects.These defects are classified into three types:surface defects,internal defects,an...Based on inspection data,the authors analyze and summarize the main types and distribution characteristics of tunnel structural defects.These defects are classified into three types:surface defects,internal defects,and defects behind the structure.To address the need for rapid detection of different defect types,the current state of rapid detection technologies and equipment,both domestically and internationally,is systematically reviewed.The research reveals that surface defect detection technologies and equipment have developed rapidly in recent years.Notably,the integration of machine vision and laser scanning technologies have significantly improved detection efficiency and accuracy,achieving crack detection precision of up to 0.1 mm.However,the non-contact rapid detection of internal and behind-the-structure defects remains constrained by hardware limitations,with traditional detection remaining dominant.Nevertheless,phased array radar,ultrasonic,and acoustic vibration detection technologies have become research hotspots in recent years,offering promising directions for detecting these challenging defect types.Additionally,the application of multisensor fusion technology in rapid detection equipment has further enhanced detection capabilities.Devices such as cameras,3D laser scanners,infrared thermal imagers,and radar demonstrate significant advantages in rapid detection.Future research in tunnel inspection should prioritize breakthroughs in rapid detection technologies for internal and behind-the-structure defects.Efforts should also focus on developing multifunctional integrated detection vehicles that can simultaneously inspect both surface and internal structures.Furthermore,progress in fully automated,intelligent systems with precise defect identification and real-time reporting will be essential to significantly improve the efficiency and accuracy of tunnel inspection.展开更多
Point-of-care testing(POCT)refers to a category of diagnostic tests that are performed at or near to the site of the patients(also called bedside testing)and is capable of obtaining accurate results in a short time by...Point-of-care testing(POCT)refers to a category of diagnostic tests that are performed at or near to the site of the patients(also called bedside testing)and is capable of obtaining accurate results in a short time by using portable diagnostic devices,avoiding sending samples to the medical laboratories.It has been extensively explored for diagnosing and monitoring patients’diseases and health conditions with the assistance of development in biochemistry and microfluidics.Microfluidic paper-based analytical devices(μPADs)have gained dramatic popularity in POCT because of their simplicity,user-friendly,fast and accurate result reading and low cost.SeveralμPADs have been successfully commercialized and received excellent feedback during the past several decades.This review briefly discusses the main types ofμPADs,preparation methods and their detection principles,followed by a few representative examples.The future perspectives of the development inμPADs are also provided.展开更多
The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable energy.Both the DC circuit breaker(DCCB)and the current flow ...The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable energy.Both the DC circuit breaker(DCCB)and the current flow controller(CFC)are demanded to ensure the multiterminal DC grid to operates reliably and flexibly.However,since the CFC and the DCCB are all based on fully controlled semiconductor switches(e.g.,insulated gate bipolar transistor,integrated gate commutated thyristor,etc.),their separation configuration in the multiterminal DC grid will lead to unaffordable implementation costs and conduction power losses.To solve these problems,integrated equipment with both current flow control and fault isolation abilities is proposed,which shares the expensive and duplicated components of CFCs and DCCBs among adjacent lines.In addition,the complicated coordination control of CFCs and DCCBs can be avoided by adopting the integrated equipment in themultiterminal DC grid.In order to examine the current flow control and fault isolation abilities of the integrated equipment,the simulation model of a specific meshed four-terminal DC grid is constructed in the PSCAD/EMTDC software.Finally,the comparison between the integrated equipment and the separate solution is presented a specific result or conclusion needs to be added to the abstract.展开更多
ZFJ Textile Machinery Co.,Ltd.,established in 1949,is a key enterprise directly managed by China Hi-Tech Group Corporation and falls under the jurisdiction of China National Machinery Industry Corporation Limited(Sino...ZFJ Textile Machinery Co.,Ltd.,established in 1949,is a key enterprise directly managed by China Hi-Tech Group Corporation and falls under the jurisdiction of China National Machinery Industry Corporation Limited(Sinomach).As a leading enterprise in the textile machinery manufacturing industry,ZFJ is dedicated to providing global customers with complete equipment solutions covering the entire industry chain.During this exhibition,ZFJ primarily highlights three key features:"high-performance fibers,green fibers,and intelligent equipment,"with a focus on showcasing nine types of products,spanning various textile equipment categories,including chemical fiber,specialty fiber,nonwoven,sizing,and dyeing machinery.展开更多
基金Sponsored by Key Funding Project for Science and Technology under the Beijing Municipal Education Commission(KZ200910772001)
文摘In order to predict electromechanical equipments＇ nonlinear and non-stationary condition effectively, max Lyapunov exponent is introduced to the fault trend prediction of large rotating mechanical equipments based on chaos theory. The predict method of chaos time series and two methods of proposing f and F are dis- cussed. The arithmetic of max prediction time of chaos time series is provided. Aiming at the key part of large rotating mechanical equipments-bearing, used this prediction method the simulation experiment is carried out. The result shows that this method has excellent performance for condition trend prediction.
基金Supported by Natural Science Foundation of China(Grant No.51775501)Natural Science Foundation of Zhejiang Province,China(Grant Nos.LZ21E050003,LR16E050001,LY17E050004).
文摘As a starting point in equipment manufacturing,sawing plays an important role in industrial production.Intelligent manufacturing equipment is an important carrier of intelligent manufacturing technologies.Due to the backwardness of intelligent technology,the comprehensive performance of sawing equipments in China is obviously different from that in foreign countries.State of the art of advanced sawing equipments is investigated along with the technical bottleneck of sawing machine tool manufacturing,and a new industrial scheme of replacing turning-milling by sawing is described.The key technologies of processing-measuring integrated control,multi-body dynamic optimization,the collaborative sawing network framework,the distributed cloud sawing platform,and the self-adapting service method are analyzed;with consideration of the problems of poor processing control stableness,low single machine intelligence level,no on-line processing data service and active flutter suppression of sawing with wide-width and heavy-load working conditions.Suggested directions for further research,industry implementation,and industry-research collaboration are provided.
文摘The type of pinion and rack vertical shiplifts has been developed in recent a couple of years in the construction of dams.But the design methods and methodologies have rarely been discussed in literature.The Xiangjiaba shiplift is the second shiplift of this type following the Three Gorges shiplift.Being aimed at the technological rationality of the design in synthetically considering security,economy and applicability,this paper presents the research results of some vital issues relating the design of the Xiangjiaba shiplift,including the determination of design water depth of ship chamber based on fluid numeral computation and physical model test,the optimum design of general layout of main equipments and the civil structure of the Xiangjiaba shiplift,the finite element method(FEM) analysis of stress,vibration modes and the buckling of ship chamber,antiseismic research and the design of structures and mechanisms of the shiplift and the optimum design of driving mechanisms.This research provides the theoretical basis for the design of the Xiangjiaba shiplift.The design principles and research methods are valuable for the design of the same type of shiplifts.
基金Supported by the National Key Technological Equipment Plan of China (ZZ02030301)Longtan Hydropower Development Corpora-tion Limited of China Datang Corporation
文摘Anti-collision equipments system is developed to solve the collision problems of dam construction equipments, and in the system the determination of equipments＇ space state is important. A uniform moving equation of equipments is established based on the analysis prediction theory and the movements states of equipments. Method of least square was employed to deal with discrete data of equipments＇ space position. Fitting equation matched with the movement equation was presented to do data fitting, and a relevant algorithm was given. Applying the fitting equation, current and future space state of equipments can be accurately predicted. Finally, a case is given and results show that numerical values of data were steady and their precision was high. In LongTan dam construction of the equipments antiollision system, applying this method to forecast the equipments＇ space states and practical running of the system indicate that this method can improve the precision of position, obtain the better forecasting effect and increase the robustness of the system.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.60873191,60903152,and 60821001)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant Nos.200800131016 and 20090005110010)+1 种基金the Beijing Nova Program,China (Grant No.2008B51)the Key Program of Ministry of Education of China (Grant No.109014)
文摘We show a scheme to distribute the entanglement by using three-mode separable Gaussian state prepared with imperfect equipments. The scheme achieves the aim that the entanglement is distributed between two distant parties with only Gaussian operations and linear optics elements. Moreover, we analyse the logarithmic negativity of the entanglement shared between the two parties when the systems are imperfect and arrive at the conclusion that the logarithmic negativity is asymptotically stable with fluctuations within a certain space range.
文摘A coupled thermomechanical model is presented to investigate the thermoelastoplastic deformation mechanism of electromechanical equipments under the condition of electrocaloric shock. In the coupling model, differentiating from the previous analyzing viewpoint that looked upon deformation work as additional heat source, temperature-field equation is established by considering the weakening role of deformation work on the intensity of internal heat source; in the process of setting up displacement-field equation, G-derivative of nonlinear functional is introduced into the traditional theory of elastoplastic finite deformation to simplify the expression of structural stiffness; stress-field equation is constructed by using the least square method to improve the stress solution obtained by constitutive equation. The presented model is converted into finite element program to simulate deforming process of 3-D structures with temperature-dependent material properties. As an example, thermal deformation analysis of Shanghai metro cars’ brake resistor is performed and compared with experimental results for illustrating the validity of the presented model.
文摘Due to the limited management funds and insufficient management efforts,curing barns in traditional tobacco area are outdated and equipments are seriously damaged,which affects the normal operation and increases the maintenance cost of bulk curing barns,bringing adverse effects on tobacco leaf curing in the coming year and the sustainable development of tobacco industry in the future.To ensure the normal operation of curing barns and effectively prolong the service life of curing barns during tobacco leaf curing,we should do a good job in the publicity of management and maintenance,improve the system of management and maintenance,raise funds for management and maintenance,inspect facilities and equipments,carefully maintain equipments in curing barn and strictly perform examination and inspection.
文摘Dyeing & finishing industry makes it possible for textile products to present colorful world on them.When it beautifies human’s life immensely,it also makes great consumption of energy and resources,and causes environmental pollution.
基金supported by National Hi-tech Research and Development Program of China(863 Program,Grant No. 2009AA044801)
文摘Pressure equipments in the process industries and the newly developing industries usually have extreme sizes and/or are subjected to extreme operating conditions such as high pressure,blast loading,cryogenic temperature,elevated temperature,complex corrosion,and so on.In order to understand,research and develop these equipments systematically,a concept of extreme pressure equipments（EPEs） is proposed.The applications and demands of EPEs in petrochemical industry,coal chemical industry,advanced energy,military,space technology,and environment protection are introduced.Basic scientific problems in material,design,inspection, and safety related to EPEs are discussed.Then,take chemical composition,manufacturing process,service duration,and operating conditions for example,main factors which affect material properties of EPEs are analyzed.New design concepts including design based on life cycle,dynamic design and light-weight design are introduced.EPEs with higher efficiency,lower cost and safer performance are in urgent demand in national major projects including ten million ton oil refinery,one million ton ethylene,liquefied natural gas transportation,and nuclear power plant.Thus,further research should be conducted on information acquisition, multi-mechanism damage coupling model,damage inspection,life prediction,online safety monitoring,maintenance strategy,safety pre-warning system,and emergency system.
文摘The new technology and equipments used in alumina refinery in PINGGUO ALUMINUM COMPANY were introduced. Problems encountered during early period of its operation and improvements to the process and equipments were discussed. Current opemtion situation and pedect technical and economical figures were also introduced.
基金Sponsored by the Science and Technology Program of Heilongjiang Provicial Department of Education( Grant No 11544022)
文摘When subjected to underwater explosion,the anti-shock performance of naval equipment is a key factor affecting the fighting capacity and safety of a war ship. For large-scale naval equipment,it is costly to do the shock test for its huge mass and large size. Consequently,the numerical research was carried our to study the shock resistance of the equipment. Taking turbo-charger set for example,its anti-shock performance was studied using software ABAQUS based on the time-domain shock analysis method presented in BV043 /85. According to the analysis results,shock response of typical regions is obtained,some regularity curves are concluded by analyzing the Mises stress of the typical regions,and the weak regions are found out. The study can provide some references on design of turbo-charger set.
文摘According to the typical engineering samples, a neural net work model with genetic algorithm to optimize weight values is put forward to forecast the productivities and efficiencies of mining faces. By this model we can obtain the possible achievements of available equipment combinations under certain geological situations of fully-mechanized coal mining faces. Then theory of fuzzy selection is applied to evaluate the performance of each equipment combination. By detailed empirical analysis, this model integrates the functions of forecasting mining faces' achievements and selecting optimal equipment combination and is helpful to the decision of equipment combination for fully-mechanized coal mining.
基金Supported by Scientific and Technological Achievement Extension Project of Experimental Demonstration Station(Base)in Northwest A&F University(TGZX2016-31)Xi'an Science and Technology Project(NC1504 3)
文摘The high summer indoor temperature in agricultural greenhouse is not conducive to crop growth,so it is necessary to cool the greenhouse. In this study,taking the agricultural multi-span greenhouse with strong temperature adjustment ability for example,we make an experimental analysis on the temperature changes inside and outside the greenhouse under nine different equipment combinations( fan,skylight,sunshade,sunshade + fan,cooling pad + fan,skylight + fan,sunshade + skylight,sunshade + fan + cooling pad,sunshade + skylight + fan),respectively,and conduct the overall assessment on the measures to cool the summer agricultural greenhouse,in order to provide a reference for selecting a cost-effective cooling method for greenhouse. Tests show that the three treatment modes of fan,sunshade and sunshade + fan almost have no cooling capacity; skylight,sunshade + skylight have cooling capacity,but the effect is slow; cooling pad + fan,sunshade + skylight +fan can reduce the indoor temperature,but the effect is not very good; skylight and fan have good cooling effect; sunshade + fan + cooling pad has obvious cooling effect,which can well meet the cooling needs in the summer greenhouse.
文摘As the economic level rising,the function and stability of civil aircraft have been greatly improved.However,with the development of science and technology in modern civil aviation transportation,the frequent occurrence of flight accidents has threatened people’s safety.The main reason is the internal failure of the engine body or the daily maintenance management is incomplete.Therefore,the relevant maintenance management departments should attach great importance to the first core research and management of civil aircraft stability and safety.In view of various equipment problems existing in the operation of civil aircraft,the practical application of data collection mode and maintenance information disclosure mode of modern aircraft maintenance equipment is analyzed.This paper describes some characteristics of aircraft maintenance work,and combined with the main factors affecting the risk of civil aircraft maintenance,giving countermeasures and suggestions to effectively improve the level of civil aircraft maintenance risk management.
基金supported by NSFC under Grant No.50705072Hubei Province Natural Science Fund for Young Scientist under Grant No.2005ABB023Wuhan City Dawn Planunder Grant No.20055003059
文摘The burgeoning grid technology provides a practical possibility to share Numerical Control （NC） equipment under a Web environment via many-w-many mode which is faced with the difficulty of a driving force for grid workflow. This paper proposes the novel methodology of coupling constraints to overcome this difficulty. First, the complex constraints and the structure attributes of NC tasks are detailed in the NC equipment grid that illustrates the possibility of forming a grid workflow force by coupling constraints. Second, the principle of driving force by coupling constraints in an NC equipment grid and the relative algorithm are proposed. Finally, the case study of comparative experiment is detailed to demonstrate the efficiency of this novel tactic.
文摘Based on inspection data,the authors analyze and summarize the main types and distribution characteristics of tunnel structural defects.These defects are classified into three types:surface defects,internal defects,and defects behind the structure.To address the need for rapid detection of different defect types,the current state of rapid detection technologies and equipment,both domestically and internationally,is systematically reviewed.The research reveals that surface defect detection technologies and equipment have developed rapidly in recent years.Notably,the integration of machine vision and laser scanning technologies have significantly improved detection efficiency and accuracy,achieving crack detection precision of up to 0.1 mm.However,the non-contact rapid detection of internal and behind-the-structure defects remains constrained by hardware limitations,with traditional detection remaining dominant.Nevertheless,phased array radar,ultrasonic,and acoustic vibration detection technologies have become research hotspots in recent years,offering promising directions for detecting these challenging defect types.Additionally,the application of multisensor fusion technology in rapid detection equipment has further enhanced detection capabilities.Devices such as cameras,3D laser scanners,infrared thermal imagers,and radar demonstrate significant advantages in rapid detection.Future research in tunnel inspection should prioritize breakthroughs in rapid detection technologies for internal and behind-the-structure defects.Efforts should also focus on developing multifunctional integrated detection vehicles that can simultaneously inspect both surface and internal structures.Furthermore,progress in fully automated,intelligent systems with precise defect identification and real-time reporting will be essential to significantly improve the efficiency and accuracy of tunnel inspection.
文摘Point-of-care testing(POCT)refers to a category of diagnostic tests that are performed at or near to the site of the patients(also called bedside testing)and is capable of obtaining accurate results in a short time by using portable diagnostic devices,avoiding sending samples to the medical laboratories.It has been extensively explored for diagnosing and monitoring patients’diseases and health conditions with the assistance of development in biochemistry and microfluidics.Microfluidic paper-based analytical devices(μPADs)have gained dramatic popularity in POCT because of their simplicity,user-friendly,fast and accurate result reading and low cost.SeveralμPADs have been successfully commercialized and received excellent feedback during the past several decades.This review briefly discusses the main types ofμPADs,preparation methods and their detection principles,followed by a few representative examples.The future perspectives of the development inμPADs are also provided.
基金supported in part by Natural Science Foundation of Jiangsu Province under Grant BK20230255Natural Science Foundation of Shandong Province under Grant ZR2023QE281.
文摘The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable energy.Both the DC circuit breaker(DCCB)and the current flow controller(CFC)are demanded to ensure the multiterminal DC grid to operates reliably and flexibly.However,since the CFC and the DCCB are all based on fully controlled semiconductor switches(e.g.,insulated gate bipolar transistor,integrated gate commutated thyristor,etc.),their separation configuration in the multiterminal DC grid will lead to unaffordable implementation costs and conduction power losses.To solve these problems,integrated equipment with both current flow control and fault isolation abilities is proposed,which shares the expensive and duplicated components of CFCs and DCCBs among adjacent lines.In addition,the complicated coordination control of CFCs and DCCBs can be avoided by adopting the integrated equipment in themultiterminal DC grid.In order to examine the current flow control and fault isolation abilities of the integrated equipment,the simulation model of a specific meshed four-terminal DC grid is constructed in the PSCAD/EMTDC software.Finally,the comparison between the integrated equipment and the separate solution is presented a specific result or conclusion needs to be added to the abstract.
文摘ZFJ Textile Machinery Co.,Ltd.,established in 1949,is a key enterprise directly managed by China Hi-Tech Group Corporation and falls under the jurisdiction of China National Machinery Industry Corporation Limited(Sinomach).As a leading enterprise in the textile machinery manufacturing industry,ZFJ is dedicated to providing global customers with complete equipment solutions covering the entire industry chain.During this exhibition,ZFJ primarily highlights three key features:"high-performance fibers,green fibers,and intelligent equipment,"with a focus on showcasing nine types of products,spanning various textile equipment categories,including chemical fiber,specialty fiber,nonwoven,sizing,and dyeing machinery.
