Based on the analysis of the development process system status of domestic and foreign civil aircraft airborne system suppliers,this paper proposes the overall construction idea of"a set of civil aircraft process...Based on the analysis of the development process system status of domestic and foreign civil aircraft airborne system suppliers,this paper proposes the overall construction idea of"a set of civil aircraft process system"based on IPD(Integrated product development)in the organization.The development stage,process,activity and task are the logical framework elements of the system construction."Based on process decomposition,vertical stratification,horizontal segmentation,combination of special and common,process customized to tools,role and process integration,giving full consideration to the interface between supplier management and process modules"etc.are the concrete ideas.Moreover,formulate top⁃level system construction standards,implemented by process system management tool platform,so that the process system and development work can be effectively integrated to effectively guide the development work of airborne system suppliers,and meet the quality and airworthiness requirements of civil aircraft development.Through the development application of a certain type of flight control system,the process system and tool platform were verified and optimized in practice.展开更多
An extra-large landslide occurred on June 19,2021,on the footwall slope of the Nanfen Open-pit Iron Mine in Liaoning Province,China,with a volume of approximately 1.2×107 m3.To elucidate the causative factors,dev...An extra-large landslide occurred on June 19,2021,on the footwall slope of the Nanfen Open-pit Iron Mine in Liaoning Province,China,with a volume of approximately 1.2×107 m3.To elucidate the causative factors,development process,and destructive mechanisms of this catastrophic landslide,comprehensive field tests,investigations,and laboratory experiments were conducted.Initially,the heavily weathered rock mass of the slope was intersected by faults and joint fissures,facilitating rainwater infiltration.Moreover,the landslide contained a substantial clay mineral with highly developed micro-cracks and micro-pores,exhibiting strong water-absorption properties.As moisture content increased,the rock mass underwent softening,resulting in reduced strength.Ultimately,continuous heavy rainfall infiltration amplified the slope's weight,diminishing the weak structural plane's strength,leading to fracture propagation,slip plane penetration,and extensive tensile-shear and uplift failure of the slope.The study highlights poor geological conditions as the decisive factor for this landslide,with continuous heavy rainfall as the triggering factor.Presently,adverse environmental factors persistently affect the landslide,and deformation and failure continue to escalate.Hence,it is imperative to urgently implement integrated measures encompassing slope reinforcement,monitoring,and early-warning to real-time monitor the landslide's deformation and deep mechanical evolution trends.展开更多
The development of women’s higher education in China can be divided into four stages:emergence(1908-1948);foundation(1949-1976);accelerating development(1977-2008);and the qualitative leap(2009-2020).This work consid...The development of women’s higher education in China can be divided into four stages:emergence(1908-1948);foundation(1949-1976);accelerating development(1977-2008);and the qualitative leap(2009-2020).This work considers the principal institutional mechanisms that contributed to this development.First,flexibly planned parenthood gradually promoted gender equality and openness in society facilitated by systematic“awards,grants,and loans”initiatives to support women’s higher education economically.Second,compulsory education ensured that left-out and migrant children had access to higher education.Third,effective connectivity across different education types bridged education gaps between those with different levels of education.Fourth,China made great efforts to invite and integrate international experiences that promoted the development of women’s higher education.Looking beyond these achievements,we also discuss the future trends of women’s higher education in China.展开更多
This paper reviewed the trend and development of semi-solid metal technique. The processes and mechanisms for producing slurry of SSM and its industrial applications have been summarized and discussed. Discussions on ...This paper reviewed the trend and development of semi-solid metal technique. The processes and mechanisms for producing slurry of SSM and its industrial applications have been summarized and discussed. Discussions on the basic rheological theory are presented for more applications. Further consideration of the development and application of SSM technique is also proposed.展开更多
Concurrent engineering (CE) is a systematic approach to integrate concurrent design of products and their related processes. Its objective is to shorten product life cycle, improve product quality and reduce product c...Concurrent engineering (CE) is a systematic approach to integrate concurrent design of products and their related processes. Its objective is to shorten product life cycle, improve product quality and reduce product cost. Modeling the concurrent engineering product development process (CEPDP) is a key part of this process which has attracted the attention of researchers and engineers around the world. This paper focuses on a newly developed and potentially powerful CEPDP modeling philosophy——integrated multi view modeling (IMVM), by which managers can foresee the evolution of a product from its conception to its disposal and consider all the important factors in its production before a project is launched. CEPDP/IMVM is a product oriented modeling method. A modeling environment is used to establish a systematic model including different aspects of the process such as product information, development activities, enterprise resources, and organizational structure. The integration within an IMVM model should accurately reflect the PDPs dynamic characteristics and provide necessary information for monitoring and coordinating processes.展开更多
This article presents a multiscale simulation approach starting at the molecular level for the adsorption process development. A grand canonical Monte Carlo method is used for the prediction of adsorption isotherms of...This article presents a multiscale simulation approach starting at the molecular level for the adsorption process development. A grand canonical Monte Carlo method is used for the prediction of adsorption isotherms of methanol on an activated carbon at the molecular level. The adsorption isotherms obtained in the linear region (or adsorption constant) are exploited as a model parameter required for the adsorption process simulation. The adsorption process model described by a set of partial differential equations (PDEs) is solved by using the conservation element and solution element method, which produces a fast and an accurate numerical solution to PDEs. The simulation results obtained from the adsorption constant estimated at the molecular level are in good agreement with the experimental results of the pulse response. The systematical multiscale simulation approach addressed in this study may be useful to accelerate the adsorption process development by reducing the number of experiments.展开更多
China is currently vigorously implementing the“energy conservation and emission reduction”and“dual carbon”strategies.As the most resource-advantaged light metal material in China,Magnesium(Mg)alloy is progressivel...China is currently vigorously implementing the“energy conservation and emission reduction”and“dual carbon”strategies.As the most resource-advantaged light metal material in China,Magnesium(Mg)alloy is progressively expanding its application in automobile,rail transportation,aerospace,medical,and electronic products.Chongqing University,Shanghai Jiaotong University,and Australian National University have conducted extensive research on the preparation,properties,and processes of Mg alloys.In the past 20 years,the proportion of Mg alloy in the automotive industry has gradually expanded,whereas currently the design and development of Mg alloy parts for automobiles has rarely been reported.Thus,the application models and typical parts cases of Mg alloy are summarized mainly from the four systems of the whole vehicle(body system,chassis system,powertrain system,interior,and exterior system).Subsequently,two actual original equipment manufacturers(OEM)cases are used to introduce the development logic of reliable die-cast Mg alloy,including forward design,formability analysis,process design analysis,structural redesign,manufacturing,and testing,aiming to share the methods,processes,and focus of attention of automotive OEMs for developing Mg alloy parts to enhance the confidence and motivation of applying Mg alloy in automotive field.Eventually,the multiple challenges faced by Mg alloy materials are sorted out and how to face these challenges are discussed.National policies and regulations,environmental protection and energy saving,and consumer demand will continue to promote the application of Mg.展开更多
Today the cycle time of the product develop is requ ir ed to be shortened. At the same time the requirement of the customers becomes mo re and more diverse and complex. The capability of the develop unit is limited b ...Today the cycle time of the product develop is requ ir ed to be shortened. At the same time the requirement of the customers becomes mo re and more diverse and complex. The capability of the develop unit is limited b ecause of the existence of heterogeneous systems and distributed environments. I n this paper, we bring forward a new approach to solve the problem in product de velopment process. We also settle part key technologies in it. A great deal of information from all kinds of sources in the distributed develop ment process is interweaved. The solution to organize the workflow and manage th e information in the process is called for anxiously. We use a new approach that is asynchronous and synchronous coupling product development approach based on the network. The approach extends the develop process from the time axis. Then t he activities in the process are organized from the asynchronous and synchronous aspects. The state of every activity projects at the ASN (active semantic netwo rk). The ASN includes decision system, intelligent agent, user interface and net work. The ASN decides the types and states of the activities and deals with the couple relationship among them. The knowledge stored in ASN is open to all users through the relative interfaces. Every specialist keeps contact with their user s relying on collaborative platform implements CSCW (computer support collaborat ive work) that integrated product/process design and development. The lack of gl obal communication in product development process can be prevented in the most d egree. The key technologies that exist in the asynchronous and synchronous coupling pro duct develop approach include: integrated development structure, orderly organiz ation of information, transparent management of process, agile transfer of infor mation and rapid prototype. The development process can be completed quickly by these technologies. The technologies involve wide content. In this paper, we dis cuss some key technologies. We validate the approach by the projectrapid response manufacturing a pplication in the distributed environment. The expensive device, high technology and low using lead to RE (Rapid engineering) and RP (Rapid prototype) service a pplication by the network. RE and RP develop rapidly due to the accelerated prod uct development process. RE and RP application service platform is built in the project.展开更多
Product development process management plays an important role in concurrent engineering (CE). The integration platform is a useful tool for effectively supporting the software development and integration. Based on th...Product development process management plays an important role in concurrent engineering (CE). The integration platform is a useful tool for effectively supporting the software development and integration. Based on the analysis of practical requirements for product development process management for CE, a CORBA-based integration platform of product development process management (IP-PDPM) is designed and developed. The design principles for IP-PDPM are described. The system architecture and functions of the platform are given, the key technologies for the implementation of IP-PDPM are presented, the application integration mechanism and its implementation techniques are also detailed.展开更多
The pharyngeal dental formula of Mylopharyngodon piceus is 4-5 as a rule, and the dentition isasymmetrical. It is difficult to identify each tooth in the larval dentition. In this paper the appearancepattem of tooth g...The pharyngeal dental formula of Mylopharyngodon piceus is 4-5 as a rule, and the dentition isasymmetrical. It is difficult to identify each tooth in the larval dentition. In this paper the appearancepattem of tooth germ with developmental process in this fish is described in detail. The formationpattern of the left dentition is contrasted with that of the right one. In the developmental process,the left pharyngeal dentition lacks teeth at position An3. Thus the left dentition is D-type as designatedby Nakajima(1984), while the right one is A-type.展开更多
A methodology is presented to identify environmental impact minimization alternatives for reaction processes and assess their environmental performance. The potential environmental impact (PEI) scheme can be used to v...A methodology is presented to identify environmental impact minimization alternatives for reaction processes and assess their environmental performance. The potential environmental impact (PEI) scheme can be used to visibly display the transformation relationships among different types of PEI, identify the sources of environmental impacts, and propose alternatives for eliminating or minimizing the impacts. To evaluate the environmental performance of the alternatives effectively, some new indices, such as PEI input rate of non-products, PEI output rate of non-products per profit and the PEI conversion efficiency are proposed. Finally, the application of the methodology is illustrated using an industrial case study.展开更多
DSS have high strength,high corrosion resistance and good welding properties.Comparing with the same corrosion resistance level austenitic stainless steel,DSS decrease largely Ni content and realize the thinning of th...DSS have high strength,high corrosion resistance and good welding properties.Comparing with the same corrosion resistance level austenitic stainless steel,DSS decrease largely Ni content and realize the thinning of thickness design to perfectly optimize properties and decrease costs.Now DSS have been widely used in many fields such as petroleum,chemical industry,paper production,shipbuilding,nuclear power, seawater desalting,vacuum salt production and architecture.Tisco have began the process development and product application research of DSS products from last century and gradually solved a lot of technical problems such as AOD nitrogen alloying control of various content DSS,high temperature deformation mechanism of thermal process,large deformation hot rolling process of coils,the effect of bad phase precipitated during hot treatment process on properties and high efficiency pickling of high Cr/Mo content DSS plates.The various alloy content DSS plates and wide cold rolling coils(3Re60,S32101,S32304, S31803,S32205,S32750 and SUS329J4L) were successfully developed and used in national important constructions,key industries and abroad projects.展开更多
1 Introduction The 21st century is coming and the world iron and steel making technology is facing an important technical evolution at this century turnover,which is reflected in two aspects:①Rapid development of tra...1 Introduction The 21st century is coming and the world iron and steel making technology is facing an important technical evolution at this century turnover,which is reflected in two aspects:①Rapid development of traditional iron&steel making technology with continuous regeneration;②Three major frontier techniques of metallurgy(smelting reduction;near-net-shape continuous展开更多
Since the launch of the economic reform and opening to the outside world, China has seen rapid growth in its export of mechanical and electrical products, with its export
Grape pistil has an important influence on fruit size and quality.However,there were few studies on grape ovary,and the development process of the ovary is still unclear.Therefore,in this paper,four different grape va...Grape pistil has an important influence on fruit size and quality.However,there were few studies on grape ovary,and the development process of the ovary is still unclear.Therefore,in this paper,four different grape varieties with different lengths of small inflorescences,namely‘Musct Hambourg’grape(Vitis vinifera),‘Concord’grape(Vitis labrusca),‘ShanPuTao’grape(Vitis amurensis)and‘GongNiang2Hao’grape(Vitis amurensis×Vitis vinifera)were used as test materials.Four varieties ovary were significant differences by means of stereomicroscope,paraffin section.The expression of ovary determining gene VvAGAMOUS(VvAG)and its development related genes VvCRABS CLAW(VvCRC)and VvAGAMOUS-LIKE 11(VvAGL11)with similar functions during the development of different grape varieties were preliminarily explored using fluorescence quantitative test.The relationship between VvAG and VvCRC,VvAG and VvAGL11 were analyzed using Y1H assay.Our results showed that there were obvious abdominal sutures on the surface of expect for‘Musct Hambourg’grape,and existing poly carpels.The ovary development of‘ShanPuTao’and‘GongNiang2Hao’grape was completed when the inflorescence length was less than 1 cm,while the‘Concord’and‘Musct Hambourg’grape were fully developed when the length of inflorescence was 3–4 and 4–5 cm,respectively.VvAG and VvCRC began to express in large quantities after the formation of stamen primordia,while VvAGL11 during the forming of ovule primordia.Therefore,VvAG and VvCRC mainly regulated the development of stamens and carpels and also promote the development of ovules,while VvAGL11 major regulated the development of ovules.The promoters of VvCRC and VvAGL11 were bound by VvAG.This study provides an important theoretical basis for further research on the molecular mechanism of grape ovary development.展开更多
Tsinghua-TOYO Research and Development Center of Magnesium and Aluminum Alloys Processing Technology was officially established between Tsinghua University and TOYO Machinery & Metal Co. on Feb. 26, 2002, which is...Tsinghua-TOYO Research and Development Center of Magnesium and Aluminum Alloys Processing Technology was officially established between Tsinghua University and TOYO Machinery & Metal Co. on Feb. 26, 2002, which is a non-independent legal research organization located in Department of Mechanical Engineering of Tsinghua University. The center was equipped with one set of 650t automatic magnesium and aluminum alloys diecasting machine and necessary accessories including the melting furnaces for magnesium alloys and aluminum alloys, an accurate magnesium pump to transfer the magnesium alloys to the shot sleeve of the die casting machine, a die temperature controller, and data logging systems for cavity pressure and die temperature distributions, etc. The center is aimed to the research and development of magnesium and aluminum die casting process and their related technologies, and the main research contents include:展开更多
The implementation of product development process management (PDPM) is an effective means of developing products with higher quality in shorter lead time. It is argued in this paper that product, data, person and acti...The implementation of product development process management (PDPM) is an effective means of developing products with higher quality in shorter lead time. It is argued in this paper that product, data, person and activity are basic factors in PDPM With detailed analysis of these basic factors and their relations in product developmed process, all product development activities are considered as tasks and the management of product development process is regarded as the management of task execution A task decomposition based product development model is proposed with methods of constructing task relation matrix from layer model and constraint model resulted from task decomposition. An algorithm for constructing directed task graph is given and is used in the management of tasks. Finally, the usage and limitation of the proposed PDPM model is given with further work proposed.展开更多
In concurrent engineering, effective process management is the key to improve the efficiency and quality of product development. Although in project management system, workflow management system and PDM system, proces...In concurrent engineering, effective process management is the key to improve the efficiency and quality of product development. Although in project management system, workflow management system and PDM system, process management functions are provided, they can not meet the needs of product development. In this paper, we integrate the project management, workflow management and product management technique together and a concurrent engineering oriented integrated product development process management system is proposed. The system structure, integrated product development model and running method are introduced. The practice proves this system is powerful in supporting product development process.展开更多
文摘Based on the analysis of the development process system status of domestic and foreign civil aircraft airborne system suppliers,this paper proposes the overall construction idea of"a set of civil aircraft process system"based on IPD(Integrated product development)in the organization.The development stage,process,activity and task are the logical framework elements of the system construction."Based on process decomposition,vertical stratification,horizontal segmentation,combination of special and common,process customized to tools,role and process integration,giving full consideration to the interface between supplier management and process modules"etc.are the concrete ideas.Moreover,formulate top⁃level system construction standards,implemented by process system management tool platform,so that the process system and development work can be effectively integrated to effectively guide the development work of airborne system suppliers,and meet the quality and airworthiness requirements of civil aircraft development.Through the development application of a certain type of flight control system,the process system and tool platform were verified and optimized in practice.
基金supported by the National Natural Science Foundation of China(Grant No.52074295)the State Key Laboratory for GeoMechanics and Deep Underground Engineering,China University of Mining&Technology,Beijing(Grant No.SKLGDUEK202217).
文摘An extra-large landslide occurred on June 19,2021,on the footwall slope of the Nanfen Open-pit Iron Mine in Liaoning Province,China,with a volume of approximately 1.2×107 m3.To elucidate the causative factors,development process,and destructive mechanisms of this catastrophic landslide,comprehensive field tests,investigations,and laboratory experiments were conducted.Initially,the heavily weathered rock mass of the slope was intersected by faults and joint fissures,facilitating rainwater infiltration.Moreover,the landslide contained a substantial clay mineral with highly developed micro-cracks and micro-pores,exhibiting strong water-absorption properties.As moisture content increased,the rock mass underwent softening,resulting in reduced strength.Ultimately,continuous heavy rainfall infiltration amplified the slope's weight,diminishing the weak structural plane's strength,leading to fracture propagation,slip plane penetration,and extensive tensile-shear and uplift failure of the slope.The study highlights poor geological conditions as the decisive factor for this landslide,with continuous heavy rainfall as the triggering factor.Presently,adverse environmental factors persistently affect the landslide,and deformation and failure continue to escalate.Hence,it is imperative to urgently implement integrated measures encompassing slope reinforcement,monitoring,and early-warning to real-time monitor the landslide's deformation and deep mechanical evolution trends.
基金“Promoting research by writing”:Exploring the code of writing,supported by the Special Fund for basic scientific research of the Central University,Northwestern Polytechnical University(project no.KCJS23WT25).“Research on the construction of the linking-up curriculum system:Taking the industry characteristic research university as an example”was established by the Ministry of Education’s Youth Fund for Humanities and Social Sciences,the Department of Social Sciences of the Ministry of Education(project no.23YJC880099).
文摘The development of women’s higher education in China can be divided into four stages:emergence(1908-1948);foundation(1949-1976);accelerating development(1977-2008);and the qualitative leap(2009-2020).This work considers the principal institutional mechanisms that contributed to this development.First,flexibly planned parenthood gradually promoted gender equality and openness in society facilitated by systematic“awards,grants,and loans”initiatives to support women’s higher education economically.Second,compulsory education ensured that left-out and migrant children had access to higher education.Third,effective connectivity across different education types bridged education gaps between those with different levels of education.Fourth,China made great efforts to invite and integrate international experiences that promoted the development of women’s higher education.Looking beyond these achievements,we also discuss the future trends of women’s higher education in China.
基金the National Natural Science foundation of China! (59995440)
文摘This paper reviewed the trend and development of semi-solid metal technique. The processes and mechanisms for producing slurry of SSM and its industrial applications have been summarized and discussed. Discussions on the basic rheological theory are presented for more applications. Further consideration of the development and application of SSM technique is also proposed.
文摘Concurrent engineering (CE) is a systematic approach to integrate concurrent design of products and their related processes. Its objective is to shorten product life cycle, improve product quality and reduce product cost. Modeling the concurrent engineering product development process (CEPDP) is a key part of this process which has attracted the attention of researchers and engineers around the world. This paper focuses on a newly developed and potentially powerful CEPDP modeling philosophy——integrated multi view modeling (IMVM), by which managers can foresee the evolution of a product from its conception to its disposal and consider all the important factors in its production before a project is launched. CEPDP/IMVM is a product oriented modeling method. A modeling environment is used to establish a systematic model including different aspects of the process such as product information, development activities, enterprise resources, and organizational structure. The integration within an IMVM model should accurately reflect the PDPs dynamic characteristics and provide necessary information for monitoring and coordinating processes.
基金the Basic Research Program of the Korea Science & Engineering Foundation (KoSEF, No. R01-2006-000-10786-0).
文摘This article presents a multiscale simulation approach starting at the molecular level for the adsorption process development. A grand canonical Monte Carlo method is used for the prediction of adsorption isotherms of methanol on an activated carbon at the molecular level. The adsorption isotherms obtained in the linear region (or adsorption constant) are exploited as a model parameter required for the adsorption process simulation. The adsorption process model described by a set of partial differential equations (PDEs) is solved by using the conservation element and solution element method, which produces a fast and an accurate numerical solution to PDEs. The simulation results obtained from the adsorption constant estimated at the molecular level are in good agreement with the experimental results of the pulse response. The systematical multiscale simulation approach addressed in this study may be useful to accelerate the adsorption process development by reducing the number of experiments.
基金supported partly by the Fundamental Research Funds for Central Universities(No.06500203 and No.00007735).
文摘China is currently vigorously implementing the“energy conservation and emission reduction”and“dual carbon”strategies.As the most resource-advantaged light metal material in China,Magnesium(Mg)alloy is progressively expanding its application in automobile,rail transportation,aerospace,medical,and electronic products.Chongqing University,Shanghai Jiaotong University,and Australian National University have conducted extensive research on the preparation,properties,and processes of Mg alloys.In the past 20 years,the proportion of Mg alloy in the automotive industry has gradually expanded,whereas currently the design and development of Mg alloy parts for automobiles has rarely been reported.Thus,the application models and typical parts cases of Mg alloy are summarized mainly from the four systems of the whole vehicle(body system,chassis system,powertrain system,interior,and exterior system).Subsequently,two actual original equipment manufacturers(OEM)cases are used to introduce the development logic of reliable die-cast Mg alloy,including forward design,formability analysis,process design analysis,structural redesign,manufacturing,and testing,aiming to share the methods,processes,and focus of attention of automotive OEMs for developing Mg alloy parts to enhance the confidence and motivation of applying Mg alloy in automotive field.Eventually,the multiple challenges faced by Mg alloy materials are sorted out and how to face these challenges are discussed.National policies and regulations,environmental protection and energy saving,and consumer demand will continue to promote the application of Mg.
文摘Today the cycle time of the product develop is requ ir ed to be shortened. At the same time the requirement of the customers becomes mo re and more diverse and complex. The capability of the develop unit is limited b ecause of the existence of heterogeneous systems and distributed environments. I n this paper, we bring forward a new approach to solve the problem in product de velopment process. We also settle part key technologies in it. A great deal of information from all kinds of sources in the distributed develop ment process is interweaved. The solution to organize the workflow and manage th e information in the process is called for anxiously. We use a new approach that is asynchronous and synchronous coupling product development approach based on the network. The approach extends the develop process from the time axis. Then t he activities in the process are organized from the asynchronous and synchronous aspects. The state of every activity projects at the ASN (active semantic netwo rk). The ASN includes decision system, intelligent agent, user interface and net work. The ASN decides the types and states of the activities and deals with the couple relationship among them. The knowledge stored in ASN is open to all users through the relative interfaces. Every specialist keeps contact with their user s relying on collaborative platform implements CSCW (computer support collaborat ive work) that integrated product/process design and development. The lack of gl obal communication in product development process can be prevented in the most d egree. The key technologies that exist in the asynchronous and synchronous coupling pro duct develop approach include: integrated development structure, orderly organiz ation of information, transparent management of process, agile transfer of infor mation and rapid prototype. The development process can be completed quickly by these technologies. The technologies involve wide content. In this paper, we dis cuss some key technologies. We validate the approach by the projectrapid response manufacturing a pplication in the distributed environment. The expensive device, high technology and low using lead to RE (Rapid engineering) and RP (Rapid prototype) service a pplication by the network. RE and RP develop rapidly due to the accelerated prod uct development process. RE and RP application service platform is built in the project.
文摘Product development process management plays an important role in concurrent engineering (CE). The integration platform is a useful tool for effectively supporting the software development and integration. Based on the analysis of practical requirements for product development process management for CE, a CORBA-based integration platform of product development process management (IP-PDPM) is designed and developed. The design principles for IP-PDPM are described. The system architecture and functions of the platform are given, the key technologies for the implementation of IP-PDPM are presented, the application integration mechanism and its implementation techniques are also detailed.
基金This project was funded by the International Cooperation of japan-Chinathe National Natural Science Foundation of China
文摘The pharyngeal dental formula of Mylopharyngodon piceus is 4-5 as a rule, and the dentition isasymmetrical. It is difficult to identify each tooth in the larval dentition. In this paper the appearancepattem of tooth germ with developmental process in this fish is described in detail. The formationpattern of the left dentition is contrasted with that of the right one. In the developmental process,the left pharyngeal dentition lacks teeth at position An3. Thus the left dentition is D-type as designatedby Nakajima(1984), while the right one is A-type.
基金National Natural Science Foundation of China(No.20176045)Major State Basic Research Development Program(No.G20000263)
文摘A methodology is presented to identify environmental impact minimization alternatives for reaction processes and assess their environmental performance. The potential environmental impact (PEI) scheme can be used to visibly display the transformation relationships among different types of PEI, identify the sources of environmental impacts, and propose alternatives for eliminating or minimizing the impacts. To evaluate the environmental performance of the alternatives effectively, some new indices, such as PEI input rate of non-products, PEI output rate of non-products per profit and the PEI conversion efficiency are proposed. Finally, the application of the methodology is illustrated using an industrial case study.
文摘DSS have high strength,high corrosion resistance and good welding properties.Comparing with the same corrosion resistance level austenitic stainless steel,DSS decrease largely Ni content and realize the thinning of thickness design to perfectly optimize properties and decrease costs.Now DSS have been widely used in many fields such as petroleum,chemical industry,paper production,shipbuilding,nuclear power, seawater desalting,vacuum salt production and architecture.Tisco have began the process development and product application research of DSS products from last century and gradually solved a lot of technical problems such as AOD nitrogen alloying control of various content DSS,high temperature deformation mechanism of thermal process,large deformation hot rolling process of coils,the effect of bad phase precipitated during hot treatment process on properties and high efficiency pickling of high Cr/Mo content DSS plates.The various alloy content DSS plates and wide cold rolling coils(3Re60,S32101,S32304, S31803,S32205,S32750 and SUS329J4L) were successfully developed and used in national important constructions,key industries and abroad projects.
文摘1 Introduction The 21st century is coming and the world iron and steel making technology is facing an important technical evolution at this century turnover,which is reflected in two aspects:①Rapid development of traditional iron&steel making technology with continuous regeneration;②Three major frontier techniques of metallurgy(smelting reduction;near-net-shape continuous
文摘Since the launch of the economic reform and opening to the outside world, China has seen rapid growth in its export of mechanical and electrical products, with its export
基金financially supported from the Shanxi Youth Science Research Project(Grant No.20210302124067)the Shanxi Agricultural University Doctoral Research Startup Project(Grant No.2021BQ32)+2 种基金the Shanxi Provincial Doctoral Graduates and Postdoctoral ResearchersWorking in Shanxi Reward Fund Research Project(Grant No.SXBYKY2021075)the National Youth Science Foundation Project(Grant No.32202456)the earmarked fund for Modern Agro-Industry Technology Research System.
文摘Grape pistil has an important influence on fruit size and quality.However,there were few studies on grape ovary,and the development process of the ovary is still unclear.Therefore,in this paper,four different grape varieties with different lengths of small inflorescences,namely‘Musct Hambourg’grape(Vitis vinifera),‘Concord’grape(Vitis labrusca),‘ShanPuTao’grape(Vitis amurensis)and‘GongNiang2Hao’grape(Vitis amurensis×Vitis vinifera)were used as test materials.Four varieties ovary were significant differences by means of stereomicroscope,paraffin section.The expression of ovary determining gene VvAGAMOUS(VvAG)and its development related genes VvCRABS CLAW(VvCRC)and VvAGAMOUS-LIKE 11(VvAGL11)with similar functions during the development of different grape varieties were preliminarily explored using fluorescence quantitative test.The relationship between VvAG and VvCRC,VvAG and VvAGL11 were analyzed using Y1H assay.Our results showed that there were obvious abdominal sutures on the surface of expect for‘Musct Hambourg’grape,and existing poly carpels.The ovary development of‘ShanPuTao’and‘GongNiang2Hao’grape was completed when the inflorescence length was less than 1 cm,while the‘Concord’and‘Musct Hambourg’grape were fully developed when the length of inflorescence was 3–4 and 4–5 cm,respectively.VvAG and VvCRC began to express in large quantities after the formation of stamen primordia,while VvAGL11 during the forming of ovule primordia.Therefore,VvAG and VvCRC mainly regulated the development of stamens and carpels and also promote the development of ovules,while VvAGL11 major regulated the development of ovules.The promoters of VvCRC and VvAGL11 were bound by VvAG.This study provides an important theoretical basis for further research on the molecular mechanism of grape ovary development.
文摘Tsinghua-TOYO Research and Development Center of Magnesium and Aluminum Alloys Processing Technology was officially established between Tsinghua University and TOYO Machinery & Metal Co. on Feb. 26, 2002, which is a non-independent legal research organization located in Department of Mechanical Engineering of Tsinghua University. The center was equipped with one set of 650t automatic magnesium and aluminum alloys diecasting machine and necessary accessories including the melting furnaces for magnesium alloys and aluminum alloys, an accurate magnesium pump to transfer the magnesium alloys to the shot sleeve of the die casting machine, a die temperature controller, and data logging systems for cavity pressure and die temperature distributions, etc. The center is aimed to the research and development of magnesium and aluminum die casting process and their related technologies, and the main research contents include:
文摘The implementation of product development process management (PDPM) is an effective means of developing products with higher quality in shorter lead time. It is argued in this paper that product, data, person and activity are basic factors in PDPM With detailed analysis of these basic factors and their relations in product developmed process, all product development activities are considered as tasks and the management of product development process is regarded as the management of task execution A task decomposition based product development model is proposed with methods of constructing task relation matrix from layer model and constraint model resulted from task decomposition. An algorithm for constructing directed task graph is given and is used in the management of tasks. Finally, the usage and limitation of the proposed PDPM model is given with further work proposed.
文摘In concurrent engineering, effective process management is the key to improve the efficiency and quality of product development. Although in project management system, workflow management system and PDM system, process management functions are provided, they can not meet the needs of product development. In this paper, we integrate the project management, workflow management and product management technique together and a concurrent engineering oriented integrated product development process management system is proposed. The system structure, integrated product development model and running method are introduced. The practice proves this system is powerful in supporting product development process.