The China-Europe International Symposium on Software Engineering Education(CEISEE)is an international educational conference jointly initiated by Harbin Institute of Technology and Technological University Dublin in 2...The China-Europe International Symposium on Software Engineering Education(CEISEE)is an international educational conference jointly initiated by Harbin Institute of Technology and Technological University Dublin in 2005.The CEISEE is held alternately in China and Europe every year.The host cities include Harbin,Dublin in Ireland,Guangzhou,Bordeaux in France,Xi’an,Northampton in the United Kingdom,Shanghai,Milan in Italy,Chengdu,Zwikau in Germany,Shenyang,Athens in Greece,Shenzhen,Lisbon in Portugal,Beijing,and Wuhan in 2023.The conference has been gaining increasing international influence.展开更多
With rapid development of the new generation information technology and its wide applications,human society is coming into the new phase of digital world supported by metaverse.Software engineering education will also...With rapid development of the new generation information technology and its wide applications,human society is coming into the new phase of digital world supported by metaverse.Software engineering education will also be influenced and promoted by metaverse.The theme of 2022 China-Europe International Symposium on Software Engineering Education,CEISEE 2022,is defined as“How the metaverse is shaping the future of education”.展开更多
In view of the increasingly rapid development of global economic integration and combined with the existing modes of training international software engineering talents in China,this paper deeply analyzes and obtains ...In view of the increasingly rapid development of global economic integration and combined with the existing modes of training international software engineering talents in China,this paper deeply analyzes and obtains the existing problems in the current teaching process,and proposes various teaching reform measures under the guidance of CDIO higher engineering education thought.Through many years of teaching practice experience,we can find that our reform has achieved remarkable results.展开更多
In recent years,the IT industry in China has developed rapidly and made remarkable achievements.However,there is still a big gap between China and foreign countries in the core fields of information technology,such as...In recent years,the IT industry in China has developed rapidly and made remarkable achievements.However,there is still a big gap between China and foreign countries in the core fields of information technology,such as system hardware and software platform.Currently,foreign countries have gradually raised the restrictions of information technology in China,and even added many domestic enterprises to the restricted list,which has rung the alarm to the information security of the country.Therefore,in order to break through the foreign technology blockade and find a unique way in independent software and hardware platform,it is urgent to carry out the curriculum construction and talent training mechanism on core software and hardware platform.HarmonyOS is a“future-oriented”distributed operating system developed by Huawei.It proposes a distributed concept based on the same system capability and adapts to a variety of terminal forms,and supports a variety of terminal devices such as mobile phones,watches and smart screens.Our course on HarmonyOS aims to increase the theoretical knowledge of the core independent software and hardware platform.In the course,we exploit our teaching reform experience in the course of“Mobile Application Development”,and investigate the teaching mechanism of HarmonyOS to contribute to the rapid development of information technology and ecological construction in China.展开更多
The concept of“New Engineering”has put forward new challenges to the talents cultivation of universities.Due to some problems of the traditional Software Engineering curriculum,e.g.separated design at undergraduate-...The concept of“New Engineering”has put forward new challenges to the talents cultivation of universities.Due to some problems of the traditional Software Engineering curriculum,e.g.separated design at undergraduate-level and graduate-level courses,poor curriculum structure,lacking of industry characteristics.This paper proposes an integrated undergraduate-graduate education curriculum for Software Engineering Major,which is based on Software Engineering specialty knowledge system(C-SWEBOK)and focuses on the current national strategic demands.Additionally,the curriculum combines with the University’s transportation characteristics,and fuses the discipline of Software Engineering and Intelligent Transportation.The multi-level curriculum designed in this paper is with reasonable structure,complete system,progressive content,and salient feature,which provides the strong support for cultivating high-qualified software talents in line with national strategies and industry needs.展开更多
Discrete mathematics studies the respective structures,laws and interrelationships of different discrete quantities,which has a wide range of applications in computer science and software engineering.It has the charac...Discrete mathematics studies the respective structures,laws and interrelationships of different discrete quantities,which has a wide range of applications in computer science and software engineering.It has the characteristics of research,practice and innovation.The teaching goals of the course of discrete mathematics include not only the understanding and mastery of knowledge,but also the study of methodology.However,current teaching mechanism has limitations in outdated course contents,rare real project examples and nonscientific scoring modes.This paper attempts to think about the course construction of discrete mathematics to improve the teaching effects and cultivate students’practical ability.展开更多
With rapidly increasing massive data,mankind is entering a new era of big data.This brings new opportunities and challenges to modern society,and big data techniques also play an important role in advancing techniques...With rapidly increasing massive data,mankind is entering a new era of big data.This brings new opportunities and challenges to modern society,and big data techniques also play an important role in advancing techniques of computer science(CS)and software engineering(SE).To keep pace with developments in technology,more and more university universities are incorporating big data into their curriculum courses.However,it is distinguished from traditional CS/SE courses and big data courses.This paper attempts to think deeply about the course construction of introduction to big data from the cultivation of data thinking,and further explore the implementation result and existing problems of the course,so as to better carry out the teaching of big data course.展开更多
In recent years,with the changes in the international competitive environment,the development strategic focuses of the national software industry have also shifted.To adapt to these changes,we analyze and summarize th...In recent years,with the changes in the international competitive environment,the development strategic focuses of the national software industry have also shifted.To adapt to these changes,we analyze and summarize the problems existing in the teaching content and methods of the traditional“Operating System”course and carry out the reform and practice of this core course for software engineering majors.First,we design and integrate domestic operating system examples into the course to meet the needs of national strategic development,thus cultivating operating system software talents in line with China’s national conditions and needs.Second,we reconstruct the teaching content of the course,strengthen the assessment of comprehensive ability,and establish a 3-level progressive teaching structure.Third,we carry out the deep integration of university and enterprise to realize the combination of theory and practice and establish a comprehensive and whole process university-enterprise course co-construction mode.Through the above reform measures,students show a strong interest in learning the operating system course.The operating system course has won the honor of the first-class course of Beijing Jiaotong University and has been approved for 4 industry-education cooperation projects of the Ministry of Education.展开更多
"Semester Training"has been adopted as an important part of the personnel training in software engineering majors since it was first put forward.The ultimate goal of semester training is to improve the profe..."Semester Training"has been adopted as an important part of the personnel training in software engineering majors since it was first put forward.The ultimate goal of semester training is to improve the professional quality of students in an all-round way,then eventually achieve the goal of satisfactory employment for both students and enterprises.However,in order to achieve the above purpose,the design of traditional training project still has the following problems:the topic selection of traditional training is designed by teachers in college,which lacks the training of engineering ability aiming at practical problems;the content and technology of traditional project training are out of date,ignoring the urgent demand of software industry development for advanced technology application;the traditional project training inspects the mastery of knowledge in each semester Degree,ignores the incremental of a progressive training system.In view of the above problems,this study proposes an Application-Oriented Software Engineering Semester Training System.Practice has proved that the construction of the training system can effectively improve the quality of teaching,so as to further improve the comprehensive quality of students.展开更多
Mobile Application Development is a well-known undergraduate specialized course majoring in Computer Science and Software Engineering.Since it is a rapid developing technique and requires extensive project samples to ...Mobile Application Development is a well-known undergraduate specialized course majoring in Computer Science and Software Engineering.Since it is a rapid developing technique and requires extensive project samples to help understand,current teaching mechanism has still limitations in rare real project examples,outdated course contents,and lack of automatic assessment platforms.In order to improve the teaching effects and cultivate students’practical ability,we employ this teaching reform with industrial projects,double instructors,and automatic assessment platform to allow students participating in every course process.We aim to improve students’practical and collaboration ability during conducting the project spontaneously,and cultivate their awareness of self-learning and lifelong learning.Our classroom feedback has demonstrated that this teaching reform is effective on improving students’practical abilities,learning initiatives and comprehensive qualities.展开更多
The emergence of the Harmony operating system independently developed by Huawei has provided new opportunities and challenges for the development of our country’s information industry.This paper mainly introduces how...The emergence of the Harmony operating system independently developed by Huawei has provided new opportunities and challenges for the development of our country’s information industry.This paper mainly introduces how to combine ideological and political education with mobile devices software development via Harmony OS development courses,aiming to cultivate students’ability to develop applications under the Harmony OS operating system independently or in groups,as well as achieving the patriotism and national mission.展开更多
In recent years,as one of the main technical ways to realize artificial intelligence,deep learning has attracted more and more attention of researchers from universities,research institutions and Internet enterprises....In recent years,as one of the main technical ways to realize artificial intelligence,deep learning has attracted more and more attention of researchers from universities,research institutions and Internet enterprises.As a result,more and more universities are incorporating deep learning into their curriculum planning.However,there is a big difference between deep learning and previous courses.This paper attempts to think about the course construction of deep learning,and discusses the implementation and existing problems of the course,so as to better carry out the teaching of deep learning.展开更多
In order to solve the problems of students’basic difference,more course content and less class hours,it is difficult for students to apply what they have learned.This paper puts forward the teaching reform scheme of ...In order to solve the problems of students’basic difference,more course content and less class hours,it is difficult for students to apply what they have learned.This paper puts forward the teaching reform scheme of university computer foundation course.From the optimization of teaching content,the construction of case scenarios,the improvement of teaching philosophy,the adjustment of teaching mode and assessment mode,etc.,we should give prominence to teaching students in accordance with their aptitude,apply what they have learned,and fully mobilize the subjective initiative and enthusiasm of students.According to the implementation and feedback of two consecutive years,the reform effect of the course is good.展开更多
The microstructure and stress rupture properties of a new nickel-based cast superalloy were investigated with the cerium(Ce)additions of 0,19,50,96,150,and 300 ppm,respectively.The results indicated that Ce was mainly...The microstructure and stress rupture properties of a new nickel-based cast superalloy were investigated with the cerium(Ce)additions of 0,19,50,96,150,and 300 ppm,respectively.The results indicated that Ce was mainly found in M C and M 23 C 6 carbides,and it was also found to exist in the form of cerium-rich phases or inclusions.According to the microstructure evidence,Ce promoted the formation of M C carbides and aggravated the inhomogeneity of M 23 C 6 carbides along grain boundaries.It was also identi-fied that the average sizes of primary and secondaryγ’phases all decreased with the rising Ce content.The acceleration of Ti,Nb,and C segregations during solidification was attributed to the influence of cerium on the variation of carbides along grain boundaries.The stress rupture life experienced a signifi-cant drop as the Ce content increased from 19 to 300 ppm.Explorations showed that the degradation was mainly attributed to the severe degradation of M C carbides and the easily forming micro-voids around them caused by the Ce addition.In addition to that,the increments in the inhomogeneous distribution of M 23 C 6 carbides at grain boundaries and the accelerated coarsening rate ofγ’phases both induced the fracture under complex stress conditions.展开更多
The stress rupture properties and deform ation mechanism s of K4750 alloy at 650 ℃, 700 ℃, 750 ℃ and 800 ℃ were investigated. As the decrease of tem perature and stress, the stress rupture life gradually increased...The stress rupture properties and deform ation mechanism s of K4750 alloy at 650 ℃, 700 ℃, 750 ℃ and 800 ℃ were investigated. As the decrease of tem perature and stress, the stress rupture life gradually increased. A Larson-Miller Parameter (LMP) method was used for analyzing the stress rupture life under different conditions. The linear fitting formula between stress (σ) and LMP was derived as σ= 3166.455-119.969 ×LMP and the fitting coefficient w as 0.98. After testing, the dislocation configurations of all stress rupture samples w ere investigated by transm ission electron microscopy (TEM). The tem perature and stress had a significant impact on the deform ation m echanism, thereby affected the stress rupture life of K4750 alloy. As the increasing stress at a given tem perature, the deform ation m echanism gradually transform ed from Orowan looping to stacking fault shearing. Based on experim ental results, the threshold stress at 650 ℃, 700 ℃, 750 ℃ and 800 ℃ for the transition of deformation mechanism was estimated to be about 650 MPa, 530 MPa, 430 MPa and 350 MPa, respectively. Below the threshold stress,γ phase effectively hindered dislocation motion by Orowan looping mechanism, K4750 alloy had along stress rupture life. Slightly above the threshold stress, Orowan looping combining stacking fault shearing was the dom inant mechanism ,the stress rupture life decreased. As the further increase of stress, stacking fault shearing acted as the dominant deformation mechanism , the resistance to dislocation motion decreased rapidly, so the stress rupture life reduced significantly.展开更多
The precipitation behavior of different phases in a high-silicon stainless steel(6 wt%Si)during aging at 600–1050℃for24 h was investigated.The morphology,crystal structure and composition of various precipitates wer...The precipitation behavior of different phases in a high-silicon stainless steel(6 wt%Si)during aging at 600–1050℃for24 h was investigated.The morphology,crystal structure and composition of various precipitates were detailly characterized using optical microscopy,scanning electron microscopy and transmission electron microscopy.Four phases were mainly identified:χ-phase,M_6C carbides,σphase and a new type of fcc-phase.During aging at 600–900℃,the main precipitate was(Cr,Mo and Si)-richχ-phase which was directly precipitated fromγmatrix.Theχ-phase was calibrated as bcc structure with a lattice parameter of 8.90?.The peak temperature for the precipitation ofχ-phase was 800℃,and it was dissolved when aging at temperatures above 1000℃.Theσ-phase was observed only at 700℃and grew next toχ-phase.Above 700℃,a new fcc-phase was found to be precipitated along withχ-phase,with a space group of Fd3c and a lattice parameter of 12.56?.The M_6C carbides started to be precipitated at 700℃in the vicinity ofχ-phase.And its amount basically increased with the increasing of temperature.An orientation relationship between M_6C/γwas found:[100]c//[100]γ,(001)c//(001)γ,i.e.,the cube-on-cube relationship.展开更多
Air pollution is a significant risk factor contributing to the burden of disease in China.Health risk assessment and management are important to reduce the impact of air pollution on public health.To help formulate st...Air pollution is a significant risk factor contributing to the burden of disease in China.Health risk assessment and management are important to reduce the impact of air pollution on public health.To help formulate standardized health risk assessment techniques,a series of studies were conducted from 2006 to 2019.Through systematic review,study of molecular mechanisms,epidemiological investigation,and health effect monitoring,the overall project established a monitoring and evaluation indicator system,a comprehensive information platform,software for automatic data cleaning,and standardized health risk assessment techniques.Technical specifications have been issued by the National Health Commission for promoting health risk assessments across China.This paper introduces the project,the research approach,its main research accomplishments,innovations,and public health significance,and describes directions for further research.展开更多
文摘The China-Europe International Symposium on Software Engineering Education(CEISEE)is an international educational conference jointly initiated by Harbin Institute of Technology and Technological University Dublin in 2005.The CEISEE is held alternately in China and Europe every year.The host cities include Harbin,Dublin in Ireland,Guangzhou,Bordeaux in France,Xi’an,Northampton in the United Kingdom,Shanghai,Milan in Italy,Chengdu,Zwikau in Germany,Shenyang,Athens in Greece,Shenzhen,Lisbon in Portugal,Beijing,and Wuhan in 2023.The conference has been gaining increasing international influence.
文摘With rapid development of the new generation information technology and its wide applications,human society is coming into the new phase of digital world supported by metaverse.Software engineering education will also be influenced and promoted by metaverse.The theme of 2022 China-Europe International Symposium on Software Engineering Education,CEISEE 2022,is defined as“How the metaverse is shaping the future of education”.
文摘In view of the increasingly rapid development of global economic integration and combined with the existing modes of training international software engineering talents in China,this paper deeply analyzes and obtains the existing problems in the current teaching process,and proposes various teaching reform measures under the guidance of CDIO higher engineering education thought.Through many years of teaching practice experience,we can find that our reform has achieved remarkable results.
文摘In recent years,the IT industry in China has developed rapidly and made remarkable achievements.However,there is still a big gap between China and foreign countries in the core fields of information technology,such as system hardware and software platform.Currently,foreign countries have gradually raised the restrictions of information technology in China,and even added many domestic enterprises to the restricted list,which has rung the alarm to the information security of the country.Therefore,in order to break through the foreign technology blockade and find a unique way in independent software and hardware platform,it is urgent to carry out the curriculum construction and talent training mechanism on core software and hardware platform.HarmonyOS is a“future-oriented”distributed operating system developed by Huawei.It proposes a distributed concept based on the same system capability and adapts to a variety of terminal forms,and supports a variety of terminal devices such as mobile phones,watches and smart screens.Our course on HarmonyOS aims to increase the theoretical knowledge of the core independent software and hardware platform.In the course,we exploit our teaching reform experience in the course of“Mobile Application Development”,and investigate the teaching mechanism of HarmonyOS to contribute to the rapid development of information technology and ecological construction in China.
文摘The concept of“New Engineering”has put forward new challenges to the talents cultivation of universities.Due to some problems of the traditional Software Engineering curriculum,e.g.separated design at undergraduate-level and graduate-level courses,poor curriculum structure,lacking of industry characteristics.This paper proposes an integrated undergraduate-graduate education curriculum for Software Engineering Major,which is based on Software Engineering specialty knowledge system(C-SWEBOK)and focuses on the current national strategic demands.Additionally,the curriculum combines with the University’s transportation characteristics,and fuses the discipline of Software Engineering and Intelligent Transportation.The multi-level curriculum designed in this paper is with reasonable structure,complete system,progressive content,and salient feature,which provides the strong support for cultivating high-qualified software talents in line with national strategies and industry needs.
基金supported by the Hainan Provincial Natural Science Foundation of China(Grant No.620RC562)the Program of Hainan Association for Science and Technology Plans to Youth R&D Innovation(Grant No.QCXM201910)the National Natural Science Foundation of China(Grant No.61802092).
文摘Discrete mathematics studies the respective structures,laws and interrelationships of different discrete quantities,which has a wide range of applications in computer science and software engineering.It has the characteristics of research,practice and innovation.The teaching goals of the course of discrete mathematics include not only the understanding and mastery of knowledge,but also the study of methodology.However,current teaching mechanism has limitations in outdated course contents,rare real project examples and nonscientific scoring modes.This paper attempts to think about the course construction of discrete mathematics to improve the teaching effects and cultivate students’practical ability.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.2021RC235).
文摘With rapidly increasing massive data,mankind is entering a new era of big data.This brings new opportunities and challenges to modern society,and big data techniques also play an important role in advancing techniques of computer science(CS)and software engineering(SE).To keep pace with developments in technology,more and more university universities are incorporating big data into their curriculum courses.However,it is distinguished from traditional CS/SE courses and big data courses.This paper attempts to think deeply about the course construction of introduction to big data from the cultivation of data thinking,and further explore the implementation result and existing problems of the course,so as to better carry out the teaching of big data course.
基金This work is supported by the Fundamental Research Funds for the Central Universities(Grant No.2019RC026).
文摘In recent years,with the changes in the international competitive environment,the development strategic focuses of the national software industry have also shifted.To adapt to these changes,we analyze and summarize the problems existing in the teaching content and methods of the traditional“Operating System”course and carry out the reform and practice of this core course for software engineering majors.First,we design and integrate domestic operating system examples into the course to meet the needs of national strategic development,thus cultivating operating system software talents in line with China’s national conditions and needs.Second,we reconstruct the teaching content of the course,strengthen the assessment of comprehensive ability,and establish a 3-level progressive teaching structure.Third,we carry out the deep integration of university and enterprise to realize the combination of theory and practice and establish a comprehensive and whole process university-enterprise course co-construction mode.Through the above reform measures,students show a strong interest in learning the operating system course.The operating system course has won the honor of the first-class course of Beijing Jiaotong University and has been approved for 4 industry-education cooperation projects of the Ministry of Education.
基金supported by the Fundamental Research Funds for the Central Universities under Grant 2020RC011.
文摘"Semester Training"has been adopted as an important part of the personnel training in software engineering majors since it was first put forward.The ultimate goal of semester training is to improve the professional quality of students in an all-round way,then eventually achieve the goal of satisfactory employment for both students and enterprises.However,in order to achieve the above purpose,the design of traditional training project still has the following problems:the topic selection of traditional training is designed by teachers in college,which lacks the training of engineering ability aiming at practical problems;the content and technology of traditional project training are out of date,ignoring the urgent demand of software industry development for advanced technology application;the traditional project training inspects the mastery of knowledge in each semester Degree,ignores the incremental of a progressive training system.In view of the above problems,this study proposes an Application-Oriented Software Engineering Semester Training System.Practice has proved that the construction of the training system can effectively improve the quality of teaching,so as to further improve the comprehensive quality of students.
文摘Mobile Application Development is a well-known undergraduate specialized course majoring in Computer Science and Software Engineering.Since it is a rapid developing technique and requires extensive project samples to help understand,current teaching mechanism has still limitations in rare real project examples,outdated course contents,and lack of automatic assessment platforms.In order to improve the teaching effects and cultivate students’practical ability,we employ this teaching reform with industrial projects,double instructors,and automatic assessment platform to allow students participating in every course process.We aim to improve students’practical and collaboration ability during conducting the project spontaneously,and cultivate their awareness of self-learning and lifelong learning.Our classroom feedback has demonstrated that this teaching reform is effective on improving students’practical abilities,learning initiatives and comprehensive qualities.
文摘The emergence of the Harmony operating system independently developed by Huawei has provided new opportunities and challenges for the development of our country’s information industry.This paper mainly introduces how to combine ideological and political education with mobile devices software development via Harmony OS development courses,aiming to cultivate students’ability to develop applications under the Harmony OS operating system independently or in groups,as well as achieving the patriotism and national mission.
文摘In recent years,as one of the main technical ways to realize artificial intelligence,deep learning has attracted more and more attention of researchers from universities,research institutions and Internet enterprises.As a result,more and more universities are incorporating deep learning into their curriculum planning.However,there is a big difference between deep learning and previous courses.This paper attempts to think about the course construction of deep learning,and discusses the implementation and existing problems of the course,so as to better carry out the teaching of deep learning.
文摘In order to solve the problems of students’basic difference,more course content and less class hours,it is difficult for students to apply what they have learned.This paper puts forward the teaching reform scheme of university computer foundation course.From the optimization of teaching content,the construction of case scenarios,the improvement of teaching philosophy,the adjustment of teaching mode and assessment mode,etc.,we should give prominence to teaching students in accordance with their aptitude,apply what they have learned,and fully mobilize the subjective initiative and enthusiasm of students.According to the implementation and feedback of two consecutive years,the reform effect of the course is good.
基金the National Science and Technology Major Project of China(No.J2019-VI-0004-0118)the China Postdoctoral Science Foundation(No.2020M671403).
文摘The microstructure and stress rupture properties of a new nickel-based cast superalloy were investigated with the cerium(Ce)additions of 0,19,50,96,150,and 300 ppm,respectively.The results indicated that Ce was mainly found in M C and M 23 C 6 carbides,and it was also found to exist in the form of cerium-rich phases or inclusions.According to the microstructure evidence,Ce promoted the formation of M C carbides and aggravated the inhomogeneity of M 23 C 6 carbides along grain boundaries.It was also identi-fied that the average sizes of primary and secondaryγ’phases all decreased with the rising Ce content.The acceleration of Ti,Nb,and C segregations during solidification was attributed to the influence of cerium on the variation of carbides along grain boundaries.The stress rupture life experienced a signifi-cant drop as the Ce content increased from 19 to 300 ppm.Explorations showed that the degradation was mainly attributed to the severe degradation of M C carbides and the easily forming micro-voids around them caused by the Ce addition.In addition to that,the increments in the inhomogeneous distribution of M 23 C 6 carbides at grain boundaries and the accelerated coarsening rate ofγ’phases both induced the fracture under complex stress conditions.
文摘The stress rupture properties and deform ation mechanism s of K4750 alloy at 650 ℃, 700 ℃, 750 ℃ and 800 ℃ were investigated. As the decrease of tem perature and stress, the stress rupture life gradually increased. A Larson-Miller Parameter (LMP) method was used for analyzing the stress rupture life under different conditions. The linear fitting formula between stress (σ) and LMP was derived as σ= 3166.455-119.969 ×LMP and the fitting coefficient w as 0.98. After testing, the dislocation configurations of all stress rupture samples w ere investigated by transm ission electron microscopy (TEM). The tem perature and stress had a significant impact on the deform ation m echanism, thereby affected the stress rupture life of K4750 alloy. As the increasing stress at a given tem perature, the deform ation m echanism gradually transform ed from Orowan looping to stacking fault shearing. Based on experim ental results, the threshold stress at 650 ℃, 700 ℃, 750 ℃ and 800 ℃ for the transition of deformation mechanism was estimated to be about 650 MPa, 530 MPa, 430 MPa and 350 MPa, respectively. Below the threshold stress,γ phase effectively hindered dislocation motion by Orowan looping mechanism, K4750 alloy had along stress rupture life. Slightly above the threshold stress, Orowan looping combining stacking fault shearing was the dom inant mechanism ,the stress rupture life decreased. As the further increase of stress, stacking fault shearing acted as the dominant deformation mechanism , the resistance to dislocation motion decreased rapidly, so the stress rupture life reduced significantly.
文摘The precipitation behavior of different phases in a high-silicon stainless steel(6 wt%Si)during aging at 600–1050℃for24 h was investigated.The morphology,crystal structure and composition of various precipitates were detailly characterized using optical microscopy,scanning electron microscopy and transmission electron microscopy.Four phases were mainly identified:χ-phase,M_6C carbides,σphase and a new type of fcc-phase.During aging at 600–900℃,the main precipitate was(Cr,Mo and Si)-richχ-phase which was directly precipitated fromγmatrix.Theχ-phase was calibrated as bcc structure with a lattice parameter of 8.90?.The peak temperature for the precipitation ofχ-phase was 800℃,and it was dissolved when aging at temperatures above 1000℃.Theσ-phase was observed only at 700℃and grew next toχ-phase.Above 700℃,a new fcc-phase was found to be precipitated along withχ-phase,with a space group of Fd3c and a lattice parameter of 12.56?.The M_6C carbides started to be precipitated at 700℃in the vicinity ofχ-phase.And its amount basically increased with the increasing of temperature.An orientation relationship between M_6C/γwas found:[100]c//[100]γ,(001)c//(001)γ,i.e.,the cube-on-cube relationship.
基金The National Health and Family Planning Commission of the People’s Republic of China(201402022)China National Key Technology R&D Program(2006BAI19B05)+1 种基金the National Natural Science Foundation of China(20977089,81170255,30570799,81300013)Natural Science Foundation of Beijing Municipal(7164285).
文摘Air pollution is a significant risk factor contributing to the burden of disease in China.Health risk assessment and management are important to reduce the impact of air pollution on public health.To help formulate standardized health risk assessment techniques,a series of studies were conducted from 2006 to 2019.Through systematic review,study of molecular mechanisms,epidemiological investigation,and health effect monitoring,the overall project established a monitoring and evaluation indicator system,a comprehensive information platform,software for automatic data cleaning,and standardized health risk assessment techniques.Technical specifications have been issued by the National Health Commission for promoting health risk assessments across China.This paper introduces the project,the research approach,its main research accomplishments,innovations,and public health significance,and describes directions for further research.
