Ammonia plays a crucial role in contemporary society,impacting medicine,agriculture,and the chemical industry.The conventional industrial synthesis of NH_(3) through the Haber-Bosch technique,carried out under severe ...Ammonia plays a crucial role in contemporary society,impacting medicine,agriculture,and the chemical industry.The conventional industrial synthesis of NH_(3) through the Haber-Bosch technique,carried out under severe reaction conditions,leads to substantial energy consumption and environmental pollution.It is thus imperative for NH_(3) synthesis methods to be investigated under more favorable conditions.Synthesis of ammonia by electrocatalysis can effectively reduce the environmental damage and other urgent problems,which is a promising solution.Metal-nitrogen series batteries(M-N batteries),such as metal-nitrogen gas batteries,metal-nitrogen oxide batteries and metal-oxynitride batteries have been regarded recently as an exemplar of concurrent NH_(3) synthesis and energy production.Nonetheless,the large-scale application of these batteries is still limited by numerous challenges are currently existing in building high-efficiency M-N batteries,including poor Faradic efficiency and low NH_(3) yield.Therefore,a comprehensive overview of M-N batteries is offered,specifically focusing on advanced strategies for designing highly efficient cathode catalysts in anticipation of future developments.The metal anodes,cathodic electro-reduction reactions,and design principles are encompassed in the discussion,offering detailed insights to enhance understanding.Mechanisms,feasibility analyses,technoeconomic assessments,device combinations,and comparative evaluations are delved into in the review,contributing to a thorough comprehension of diverse systems and their application potential.Perspectives and opportunities for future research directions are also delineated.展开更多
BACKGROUND Advanced glycation end products(AGEs)are diabetic metabolic toxic products that cannot be ignored.Nε-(carboxymethyl)lysine(CML),a component of AGEs,could increase macrophage lipid uptake,promote foam cell ...BACKGROUND Advanced glycation end products(AGEs)are diabetic metabolic toxic products that cannot be ignored.Nε-(carboxymethyl)lysine(CML),a component of AGEs,could increase macrophage lipid uptake,promote foam cell formation,and thereby accelerate atherosclerosis.The receptor for AGEs(RAGE)and cluster of differentiation 36(CD36)were the receptors of CML.However,it is still unknown whether RAGE and CD36 play key roles in CML-promoted lipid uptake.AIM Our study aimed to explore the role of RAGE and CD36 in CML-induced macrophage lipid uptake.METHODS In this study,we examined the effect of CML on lipid uptake by Raw264.7 macrophages.After adding 10 mmol/L CML,the lipid accumulation in macrophages was confirmed by oil red O staining.Expression changes of CD36 and RAGE were detected with immunoblotting and quantitative real-time polymerase chain reaction.The interaction between CML with CD36 and RAGE was verified by immunoprecipitation.We synthesized a novel N-succinimidyl-4-18Ffluorobenzoate-CML radioactive probe.Radioactive receptor-ligand binding assays were performed to test the binding affinity between CML with CD36 and RAGE.The effects of blocking CD36 or RAGE on CML-promoting lipid uptake were also detected.RESULTS The study revealed that CML significantly promoted lipid uptake by macrophages.Immunoprecipitation and radioactive receptor-ligand binding assays indicated that CML could specifically bind to both CD36 and RAGE.CML had a higher affinity for CD36 than RAGE.ARG82,ASN71,and THR70 were the potential interacting amino acids that CD36 binds to CML Anti-CD36 and anti-RAGE could block the uptake of CML by macrophages.The lipid uptake promotion effect of CML was significantly attenuated after blocking CD36 or RAGE.CONCLUSION Our results suggest that the binding of CML with CD36 and RAGE promotes macrophage lipid uptake.展开更多
The appraisement of "the green level" for a green product is a problem that has to deal with multi aspects and multi stratification. According to the property of the items that affect "the green level...The appraisement of "the green level" for a green product is a problem that has to deal with multi aspects and multi stratification. According to the property of the items that affect "the green level" of the product, they can be divided into aspects, elements and factors. These make appreciable grades. Multi level fuzzy judgement can solve the appraisement problem that considers the influences of design, manufacture, use and recovery in all life cycle or multi life cycle of a product. In the judging process it not only deals with the action of all factors, but also continues to have all messages in grade judgement. The power coefficients stand out as the main items. An example is given to show the judgement process.展开更多
多产品企业产品种类调整有助于实现企业内资源优化配置。文章匹配2001—2013年中国工业企业数据、海关进出口产品数据与WITS关税数据,以中国-东盟《框架协议》签署作为准自然实验,通过双重差分的方法探究区域贸易政策不确定性对中国多...多产品企业产品种类调整有助于实现企业内资源优化配置。文章匹配2001—2013年中国工业企业数据、海关进出口产品数据与WITS关税数据,以中国-东盟《框架协议》签署作为准自然实验,通过双重差分的方法探究区域贸易政策不确定性对中国多产品企业出口产品种类的影响。实证结果表明,《框架协议》签署带来的区域贸易政策不确定性下降促使中国多产品企业显著增加出口产品种类,与Bernard et al.(2011)基于美加自由贸易区的研究结果形成了鲜明对比,主要原因在于东盟市场与北美市场的规模、产品结构等方面存在显著差异。此外,区域贸易政策不确定性下降对采取不同竞争策略的多产品企业出口种类的影响存在显著差异,采取质量竞争策略的多产品企业比采取数量竞争策略的多产品企业在《框架协议》签署的外生冲击下,增加更多的出口产品种类。此外,《框架协议》签署对区域贸易政策不确定性下降幅度更大的多产品企业出口产品种类的促进作用更加明显。进一步,《框架协议》签署带来的区域贸易政策不确定性下降对多产品企业出口产品种类增加的影响主要通过创新效应发生作用,而学习效应没有显著的作用。以上结论在稳健性检验中仍然成立。该研究为中国实施FTA战略、评估RCEP政策,以及理解中国制造业企业的出口多样化和企业内产品组合决策提供了新的视角。展开更多
Design change is an inevitable part of the product development process.This study proposes an improved binary multi‐objective PSO algorithm guided by problem char-acteristics(P‐BMOPSO)to solve the optimisation probl...Design change is an inevitable part of the product development process.This study proposes an improved binary multi‐objective PSO algorithm guided by problem char-acteristics(P‐BMOPSO)to solve the optimisation problem of complex product change plan considering service performance.Firstly,a complex product multi‐layer network with service performance is established for the first time to reveal the impact of change effect propagation on the product service performance.Secondly,the concept of service performance impact(SPI)is defined by decoupling the impact of strongly associated nodes on the service performance in the process of change affect propagation.Then,a triple‐objective selection model of change nodes is established,which includes the three indicators:SPI degree,change cost,and change time.Furthermore,an integer multi‐objective particle swarm optimisation algorithm guided by problem characteristics is developed to solve the model above.Experimental results on the design change problem of a certain type of Skyworth TV verify the effectiveness of the established optimisation model and the proposed P‐BMOPSO algorithm.展开更多
As two independent problems,scheduling for parts fabrication line and sequencing for mixed-model assembly line have been addressed respectively by many researchers.However,these two problems should be considered simul...As two independent problems,scheduling for parts fabrication line and sequencing for mixed-model assembly line have been addressed respectively by many researchers.However,these two problems should be considered simultaneously to improve the efficiency of the whole fabrication/assembly systems.By far,little research effort is devoted to sequencing problems for mixed-model fabrication/assembly systems.This paper is concerned about the sequencing problems in pull production systems which are composed of one mixed-model assembly line with limited intermediate buffers and two flexible parts fabrication flow lines with identical parallel machines and limited intermediate buffers.Two objectives are considered simultaneously：minimizing the total variation in parts consumption in the assembly line and minimizing the total makespan cost in the fabrication/assembly system.The integrated optimization framework,mathematical models and the method to construct the complete schedules for the fabrication lines according to the production sequences for the first stage in fabrication lines are presented.Since the above problems are non-deterministic polynomial-hard（NP-hard）,a modified multi-objective genetic algorithm is proposed for solving the models,in which a method to generate the production sequences for the fabrication lines from the production sequences for the assembly line and a method to generate the initial population are put forward,new selection,crossover and mutation operators are designed,and Pareto ranking method and sharing function method are employed to evaluate the individuals＇ fitness.The feasibility and efficiency of the multi-objective genetic algorithm is shown by computational comparison with a multi-objective simulated annealing algorithm.The sequencing problems for mixed-model production systems can be solved effectively by the proposed modified multi-objective genetic algorithm.展开更多
Multidisciplinary collaborative simulation （MCS） is an important area of research in the domain of multidisciplinary design optimization （MDO）.Although previous research for MCS has to some extent addressed some i...Multidisciplinary collaborative simulation （MCS） is an important area of research in the domain of multidisciplinary design optimization （MDO）.Although previous research for MCS has to some extent addressed some issues like using of multiple tools,integration stability,control of step size,data synchronization,etc,further work is still necessary to study how to achieve improved precision.A theoretical model is formulated to describe and analyze the integration process of MCS.A basic algorithm with equal major steps is proposed based on the model,along with two methods of implementation for the model,namely the serial method and the parallel method.A further algorithm based on convergent integration step is proposed,which has a more flexible strategy for run-time integration.The influence of interpolation techniques on simulation performance is studied as well.Simulations of the performance of various algorithms with different interpolation techniques are performed for both a simple numerical example and a complex mechatronic product.The novel algorithm based on convergent integration step,when used with a high-order interpolation technique,has better performance in terms of precision and efficiency.The innovation of this paper is mainly on the validation of high precision of the proposed convergent integration step algorithm.展开更多
Recently,both the importance and awareness relating to food safety relating to agrochemicals,chemical fertilizers,the pollution of ecosystem and unwholesome foods are growing rapidly.For the same reason,the purchaser&...Recently,both the importance and awareness relating to food safety relating to agrochemicals,chemical fertilizers,the pollution of ecosystem and unwholesome foods are growing rapidly.For the same reason,the purchaser's curiosity increases to know about the production process which can be accomplished by production traceability system.The traceability system can store and superintend the specific attribute information about products regarding the productive centre,producer and production finish data.The products undergo various circulation processes and they are being managed by individually constructed traceability system.Thus,it is difficult for the producer and the consumer to guarantee the safety from transpirable issues about the falsification of production traceability because the traceability information can be re-produced by forging through various ways.So in this paper,we proposed a system for integrated management of agro-fishery products based on quick response code(QR-code)for forgery prevention which may help to solve these issues.The proposed system makes QR-code using production information provided by producer.And then it is provided to the distributor and the consumer through integrated service model using the QR-code.Therefore,this system make sure to provide the same production traceability about the products to the distributor and the consumer and always keeps both updated with the same information.展开更多
An optimization model is established for a multi-product pipeline which has a known delivery demand and operation plan for each off-take station.The aim of this optimization model is to minimize the total pumping oper...An optimization model is established for a multi-product pipeline which has a known delivery demand and operation plan for each off-take station.The aim of this optimization model is to minimize the total pumping operation cost,considering not only factors including the energy equilibrium constraint,the maximum and minimum suction and discharge pressures constraints of pump stations,and pressure constraint at special elevation points,but also the regional differences in electricity prices along the pipeline.The dynamic programming method is applied to solve the model and to find the optimal pump configuration.展开更多
What is pursued by multi-product type and variant volume（MPTVV） production is rapid response and quick switching,so that structure of transferring line in manufacturing system is no longer unalterable.Cell formation...What is pursued by multi-product type and variant volume（MPTVV） production is rapid response and quick switching,so that structure of transferring line in manufacturing system is no longer unalterable.Cell formation（CF） algorithm is the key technology of cellular manufacturing system（CMS）.Currently,CF methods are mainly extended on the idea of group technology（GT） that covers a lot on analysis of resource capability matching and its algorithm.Various constraints are considered,but seldom utilized comprehensively.Aimed to the problem of manufacturing cell（MC） formation under MPTVV production mode,integrated formation technologies for typical MC as group type of cell（GC）,flow type of cell（FC） and inherited cell（IC） are presented based on technical analysis of CF.Oriented to practical production constraints like delivery time,product batch,equipment ability,key machine,key part and machine sharing,etc,an integrated formation model is constructed and internal interrelations of these constraints are analyzed synthetically.Ulteriorly,formation goals of types of MCs and their formation procedures under joint effect of formation constraints and rules are spread.In case study,three highly balanced GC are formed first;then FC formation are implemented based on the same data which indicate good balancing effect of cell load and flow-style production for key tasks;When task is adjusted,a new scheme is constructed on the result of FC configuration by using IC formation method,and more optimal performance of flow-style production is manifested.The proposed comparative study of different type of cells strongly explains the validation of integrated MC formation in support of rapid manufacturing resource transformation under MPTVV production mode.展开更多
PDM (product data management) is one kind of techniques based on software and database, which integrates information and process related to products. But it is not enough to perform the complication of PDM in enterpri...PDM (product data management) is one kind of techniques based on software and database, which integrates information and process related to products. But it is not enough to perform the complication of PDM in enterprises. Then the mechanism to harmonize all kinds of information and process is needed. The paper introduces a novel approach to implement the intelligent monitor of PDM based on MAS (multi agent system). It carries out the management of information and process by MC (monitor center). The paper first puts forward the architecture of the whole system, then defines the structure of MC and its interoperation mode.展开更多
Based on the productivity equation of coalbed methane(CBM) wells, three indexes, main production layer optimization index, main production layer expansion index and capacity contribution index are proposed, with which...Based on the productivity equation of coalbed methane(CBM) wells, three indexes, main production layer optimization index, main production layer expansion index and capacity contribution index are proposed, with which the three-step optimization method of production-layer combination is established. In selecting main production layer, the coal seam thickness, CBM content, coal seam permeability, coal seam reservoir pressure and coal structure are considered comprehensively to evaluate the potential of the production layer. In selecting expansion of the main production layer combination, on the premise of ensuring full and slow desorption of the main production layer and non-exposure of the main production layer out of liquid surface, the degree of mutual interference between the main and non-main production layers is comprehensively evaluated by coupling the critical desorption pressure, layer spacing and reservoir pressure gradient difference. In optimizing production layer combination, the main concern is the economic efficiency of the combined layers. Only when the contribution coefficient of the main production layer is greater than 30% and the contribution index of the other production layers is more than 10%, the economic benefit of a CBM well after being put into production can be ensured. Based on the comparative analysis of the development effect of the development test wells in Songhe of Guizhou province, it is proved that the "three-step method" for the optimization of production-layer combination is scientific and practical, and can be used to design the multi-layer commingling scheme of coalbed methane.展开更多
基金National Natural Science Foundation of China (22179065)Tianjin Graduate Research and Innovation Project (2022BKY018)。
文摘Ammonia plays a crucial role in contemporary society,impacting medicine,agriculture,and the chemical industry.The conventional industrial synthesis of NH_(3) through the Haber-Bosch technique,carried out under severe reaction conditions,leads to substantial energy consumption and environmental pollution.It is thus imperative for NH_(3) synthesis methods to be investigated under more favorable conditions.Synthesis of ammonia by electrocatalysis can effectively reduce the environmental damage and other urgent problems,which is a promising solution.Metal-nitrogen series batteries(M-N batteries),such as metal-nitrogen gas batteries,metal-nitrogen oxide batteries and metal-oxynitride batteries have been regarded recently as an exemplar of concurrent NH_(3) synthesis and energy production.Nonetheless,the large-scale application of these batteries is still limited by numerous challenges are currently existing in building high-efficiency M-N batteries,including poor Faradic efficiency and low NH_(3) yield.Therefore,a comprehensive overview of M-N batteries is offered,specifically focusing on advanced strategies for designing highly efficient cathode catalysts in anticipation of future developments.The metal anodes,cathodic electro-reduction reactions,and design principles are encompassed in the discussion,offering detailed insights to enhance understanding.Mechanisms,feasibility analyses,technoeconomic assessments,device combinations,and comparative evaluations are delved into in the review,contributing to a thorough comprehension of diverse systems and their application potential.Perspectives and opportunities for future research directions are also delineated.
基金Supported by The National Natural Science Foundation of China,No.82070455Natural Science Foundation of Jiangsu Province,No.BK20201225Medical Innovation Team Project of Jiangsu Province,No.CXTDA2017010。
文摘BACKGROUND Advanced glycation end products(AGEs)are diabetic metabolic toxic products that cannot be ignored.Nε-(carboxymethyl)lysine(CML),a component of AGEs,could increase macrophage lipid uptake,promote foam cell formation,and thereby accelerate atherosclerosis.The receptor for AGEs(RAGE)and cluster of differentiation 36(CD36)were the receptors of CML.However,it is still unknown whether RAGE and CD36 play key roles in CML-promoted lipid uptake.AIM Our study aimed to explore the role of RAGE and CD36 in CML-induced macrophage lipid uptake.METHODS In this study,we examined the effect of CML on lipid uptake by Raw264.7 macrophages.After adding 10 mmol/L CML,the lipid accumulation in macrophages was confirmed by oil red O staining.Expression changes of CD36 and RAGE were detected with immunoblotting and quantitative real-time polymerase chain reaction.The interaction between CML with CD36 and RAGE was verified by immunoprecipitation.We synthesized a novel N-succinimidyl-4-18Ffluorobenzoate-CML radioactive probe.Radioactive receptor-ligand binding assays were performed to test the binding affinity between CML with CD36 and RAGE.The effects of blocking CD36 or RAGE on CML-promoting lipid uptake were also detected.RESULTS The study revealed that CML significantly promoted lipid uptake by macrophages.Immunoprecipitation and radioactive receptor-ligand binding assays indicated that CML could specifically bind to both CD36 and RAGE.CML had a higher affinity for CD36 than RAGE.ARG82,ASN71,and THR70 were the potential interacting amino acids that CD36 binds to CML Anti-CD36 and anti-RAGE could block the uptake of CML by macrophages.The lipid uptake promotion effect of CML was significantly attenuated after blocking CD36 or RAGE.CONCLUSION Our results suggest that the binding of CML with CD36 and RAGE promotes macrophage lipid uptake.
文摘The appraisement of "the green level" for a green product is a problem that has to deal with multi aspects and multi stratification. According to the property of the items that affect "the green level" of the product, they can be divided into aspects, elements and factors. These make appreciable grades. Multi level fuzzy judgement can solve the appraisement problem that considers the influences of design, manufacture, use and recovery in all life cycle or multi life cycle of a product. In the judging process it not only deals with the action of all factors, but also continues to have all messages in grade judgement. The power coefficients stand out as the main items. An example is given to show the judgement process.
文摘多产品企业产品种类调整有助于实现企业内资源优化配置。文章匹配2001—2013年中国工业企业数据、海关进出口产品数据与WITS关税数据,以中国-东盟《框架协议》签署作为准自然实验,通过双重差分的方法探究区域贸易政策不确定性对中国多产品企业出口产品种类的影响。实证结果表明,《框架协议》签署带来的区域贸易政策不确定性下降促使中国多产品企业显著增加出口产品种类,与Bernard et al.(2011)基于美加自由贸易区的研究结果形成了鲜明对比,主要原因在于东盟市场与北美市场的规模、产品结构等方面存在显著差异。此外,区域贸易政策不确定性下降对采取不同竞争策略的多产品企业出口种类的影响存在显著差异,采取质量竞争策略的多产品企业比采取数量竞争策略的多产品企业在《框架协议》签署的外生冲击下,增加更多的出口产品种类。此外,《框架协议》签署对区域贸易政策不确定性下降幅度更大的多产品企业出口产品种类的促进作用更加明显。进一步,《框架协议》签署带来的区域贸易政策不确定性下降对多产品企业出口产品种类增加的影响主要通过创新效应发生作用,而学习效应没有显著的作用。以上结论在稳健性检验中仍然成立。该研究为中国实施FTA战略、评估RCEP政策,以及理解中国制造业企业的出口多样化和企业内产品组合决策提供了新的视角。
基金supported by The National Key Research and Development Program of China(No.2020YFB1708200).
文摘Design change is an inevitable part of the product development process.This study proposes an improved binary multi‐objective PSO algorithm guided by problem char-acteristics(P‐BMOPSO)to solve the optimisation problem of complex product change plan considering service performance.Firstly,a complex product multi‐layer network with service performance is established for the first time to reveal the impact of change effect propagation on the product service performance.Secondly,the concept of service performance impact(SPI)is defined by decoupling the impact of strongly associated nodes on the service performance in the process of change affect propagation.Then,a triple‐objective selection model of change nodes is established,which includes the three indicators:SPI degree,change cost,and change time.Furthermore,an integer multi‐objective particle swarm optimisation algorithm guided by problem characteristics is developed to solve the model above.Experimental results on the design change problem of a certain type of Skyworth TV verify the effectiveness of the established optimisation model and the proposed P‐BMOPSO algorithm.
基金supported by National Natural Science Foundation of China (Grant No.50875101)National Hi-tech Research and Development Program of China (863 Program,Grant No.2007AA04Z186)
文摘As two independent problems,scheduling for parts fabrication line and sequencing for mixed-model assembly line have been addressed respectively by many researchers.However,these two problems should be considered simultaneously to improve the efficiency of the whole fabrication/assembly systems.By far,little research effort is devoted to sequencing problems for mixed-model fabrication/assembly systems.This paper is concerned about the sequencing problems in pull production systems which are composed of one mixed-model assembly line with limited intermediate buffers and two flexible parts fabrication flow lines with identical parallel machines and limited intermediate buffers.Two objectives are considered simultaneously：minimizing the total variation in parts consumption in the assembly line and minimizing the total makespan cost in the fabrication/assembly system.The integrated optimization framework,mathematical models and the method to construct the complete schedules for the fabrication lines according to the production sequences for the first stage in fabrication lines are presented.Since the above problems are non-deterministic polynomial-hard（NP-hard）,a modified multi-objective genetic algorithm is proposed for solving the models,in which a method to generate the production sequences for the fabrication lines from the production sequences for the assembly line and a method to generate the initial population are put forward,new selection,crossover and mutation operators are designed,and Pareto ranking method and sharing function method are employed to evaluate the individuals＇ fitness.The feasibility and efficiency of the multi-objective genetic algorithm is shown by computational comparison with a multi-objective simulated annealing algorithm.The sequencing problems for mixed-model production systems can be solved effectively by the proposed modified multi-objective genetic algorithm.
基金supported by National Natural Science Foundation of China (Grant No. 61074110)National Defense Pre-Research Foundation of China (Grant No. B0420060524)
文摘Multidisciplinary collaborative simulation （MCS） is an important area of research in the domain of multidisciplinary design optimization （MDO）.Although previous research for MCS has to some extent addressed some issues like using of multiple tools,integration stability,control of step size,data synchronization,etc,further work is still necessary to study how to achieve improved precision.A theoretical model is formulated to describe and analyze the integration process of MCS.A basic algorithm with equal major steps is proposed based on the model,along with two methods of implementation for the model,namely the serial method and the parallel method.A further algorithm based on convergent integration step is proposed,which has a more flexible strategy for run-time integration.The influence of interpolation techniques on simulation performance is studied as well.Simulations of the performance of various algorithms with different interpolation techniques are performed for both a simple numerical example and a complex mechatronic product.The novel algorithm based on convergent integration step,when used with a high-order interpolation technique,has better performance in terms of precision and efficiency.The innovation of this paper is mainly on the validation of high precision of the proposed convergent integration step algorithm.
基金The MSIP(Ministry of Science,ICT&Future Planning),Korea,under the ITRC(Information Technology Research Center)support program(NIPA-2013-H0301-13-2006)supervised by the NIPA(National IT Industry Promotion Agency)
文摘Recently,both the importance and awareness relating to food safety relating to agrochemicals,chemical fertilizers,the pollution of ecosystem and unwholesome foods are growing rapidly.For the same reason,the purchaser's curiosity increases to know about the production process which can be accomplished by production traceability system.The traceability system can store and superintend the specific attribute information about products regarding the productive centre,producer and production finish data.The products undergo various circulation processes and they are being managed by individually constructed traceability system.Thus,it is difficult for the producer and the consumer to guarantee the safety from transpirable issues about the falsification of production traceability because the traceability information can be re-produced by forging through various ways.So in this paper,we proposed a system for integrated management of agro-fishery products based on quick response code(QR-code)for forgery prevention which may help to solve these issues.The proposed system makes QR-code using production information provided by producer.And then it is provided to the distributor and the consumer through integrated service model using the QR-code.Therefore,this system make sure to provide the same production traceability about the products to the distributor and the consumer and always keeps both updated with the same information.
文摘An optimization model is established for a multi-product pipeline which has a known delivery demand and operation plan for each off-take station.The aim of this optimization model is to minimize the total pumping operation cost,considering not only factors including the energy equilibrium constraint,the maximum and minimum suction and discharge pressures constraints of pump stations,and pressure constraint at special elevation points,but also the regional differences in electricity prices along the pipeline.The dynamic programming method is applied to solve the model and to find the optimal pump configuration.
基金supported by National Defence Science&Technology Foundation of China(Grant No.K1301020706)
文摘What is pursued by multi-product type and variant volume（MPTVV） production is rapid response and quick switching,so that structure of transferring line in manufacturing system is no longer unalterable.Cell formation（CF） algorithm is the key technology of cellular manufacturing system（CMS）.Currently,CF methods are mainly extended on the idea of group technology（GT） that covers a lot on analysis of resource capability matching and its algorithm.Various constraints are considered,but seldom utilized comprehensively.Aimed to the problem of manufacturing cell（MC） formation under MPTVV production mode,integrated formation technologies for typical MC as group type of cell（GC）,flow type of cell（FC） and inherited cell（IC） are presented based on technical analysis of CF.Oriented to practical production constraints like delivery time,product batch,equipment ability,key machine,key part and machine sharing,etc,an integrated formation model is constructed and internal interrelations of these constraints are analyzed synthetically.Ulteriorly,formation goals of types of MCs and their formation procedures under joint effect of formation constraints and rules are spread.In case study,three highly balanced GC are formed first;then FC formation are implemented based on the same data which indicate good balancing effect of cell load and flow-style production for key tasks;When task is adjusted,a new scheme is constructed on the result of FC configuration by using IC formation method,and more optimal performance of flow-style production is manifested.The proposed comparative study of different type of cells strongly explains the validation of integrated MC formation in support of rapid manufacturing resource transformation under MPTVV production mode.
文摘PDM (product data management) is one kind of techniques based on software and database, which integrates information and process related to products. But it is not enough to perform the complication of PDM in enterprises. Then the mechanism to harmonize all kinds of information and process is needed. The paper introduces a novel approach to implement the intelligent monitor of PDM based on MAS (multi agent system). It carries out the management of information and process by MC (monitor center). The paper first puts forward the architecture of the whole system, then defines the structure of MC and its interoperation mode.
基金Supported by the China National Science and Technology Major Project(2016ZX05044-002)the National Natural Science Foundation of China(41772155)the Fundamental Research Funds for the Central Universities of China(No.2015XKZD07)
文摘Based on the productivity equation of coalbed methane(CBM) wells, three indexes, main production layer optimization index, main production layer expansion index and capacity contribution index are proposed, with which the three-step optimization method of production-layer combination is established. In selecting main production layer, the coal seam thickness, CBM content, coal seam permeability, coal seam reservoir pressure and coal structure are considered comprehensively to evaluate the potential of the production layer. In selecting expansion of the main production layer combination, on the premise of ensuring full and slow desorption of the main production layer and non-exposure of the main production layer out of liquid surface, the degree of mutual interference between the main and non-main production layers is comprehensively evaluated by coupling the critical desorption pressure, layer spacing and reservoir pressure gradient difference. In optimizing production layer combination, the main concern is the economic efficiency of the combined layers. Only when the contribution coefficient of the main production layer is greater than 30% and the contribution index of the other production layers is more than 10%, the economic benefit of a CBM well after being put into production can be ensured. Based on the comparative analysis of the development effect of the development test wells in Songhe of Guizhou province, it is proved that the "three-step method" for the optimization of production-layer combination is scientific and practical, and can be used to design the multi-layer commingling scheme of coalbed methane.
