The external residence time distribution(RTD)curve is extensively used to characterise fluid flow within the single-strand continuous casting tundish.Dead volume fraction determination typically relies on the external...The external residence time distribution(RTD)curve is extensively used to characterise fluid flow within the single-strand continuous casting tundish.Dead volume fraction determination typically relies on the external RTD curve to reveal macroscopic fluid flow behaviour.Based on the external RTD to effectively assess dead volume fractions and other fluid characteristics under conditions of internal non-uniform flow,an internal RTD was introduced.In a smooth pipe under laminar flow conditions,the dead region occupies 25%of the total volume,which is defined as the space between the pipe wall and a radius of 0.866 R0(where R0 is the radius of pipe).Under turbulent flow conditions,the dead region only occupies 0.38%of the reactor’s internal volume,spanning from the pipe wall to a radius of 0.00189 R0.The results obtained using the external RTD method are consistent with the theoretical analysis.Experimental trials involving water were conducted to examine the flow of molten steel within a five-strand tundish.Subsequently,an analysis approach employing internal RTD was employed to evaluate fluid mixing within a multi-flow continuous casting tundish.Using the internal RTD method,the analysis revealed that the whole dead zone volume fraction of the intermediate package decreased from 26.9%to 18.9%after the addition of the flow control device.The dead volume fraction can be accurately depicted by utilising the internal mean RTD function.The association between the internal RTD function and the external average RTD can be effectively employed to scrutinise the response curve of the tracer within a system exhibiting uneven flow distribution.展开更多
Italy will host the 17th edition of ITMA, the world’s largest exhibition of textile machinery.It will be held at the Fiera Milano Rhoexhibition centre in Milan,from 12 to 19 November 2015.
This paper analyzes some problems arising in determining the mails Whole Delivery Standard of Time Bound ( WDSTB ) at present, and further on the basis of the postal central office system currently in practice, puts...This paper analyzes some problems arising in determining the mails Whole Delivery Standard of Time Bound ( WDSTB ) at present, and further on the basis of the postal central office system currently in practice, puts forward the principle, reflection and the concrete approaches in determining the Delivery Standard of Time Bound ( DSTB ).展开更多
When SAE-China participated in SAE In-ternational Congress for the first time seven years ago, there was only one member in the SAE-China delegation. While, ’98 SAE inter-national greeted the SAE-China larger delegat...When SAE-China participated in SAE In-ternational Congress for the first time seven years ago, there was only one member in the SAE-China delegation. While, ’98 SAE inter-national greeted the SAE-China larger delegation of more than 50 members, of whom about 40 members were from Chinese auto suppliers and the others from SAE-China, CAAM (China As-sociation of Automobile Manufacturers), univer-展开更多
In our times, philosophy has been suffering from a spiritual crisis that takes the forms of the crisis of culture, the crisis of meaning, and the crisis of way of life. As the soul of culture, philosophy should contri...In our times, philosophy has been suffering from a spiritual crisis that takes the forms of the crisis of culture, the crisis of meaning, and the crisis of way of life. As the soul of culture, philosophy should contribute valuable responses to the problems of our times. Thus understood, this paper intends to analyze the concept of crisis in a phenomenological approach. The concept of crisis is concerned with the philosophical themes of time and death, and the crises of our times are primarily the crises of life-meaning and the life-world. Drawing sources from Husserl and other phenomenologists, as well as experiences from Chinese culture, I argue that a philosophy of crisis should find its point of departure from the crisis of philosophy.展开更多
基金supported by grants from the National Natural Science Foundation of China(No.51774004)Anhui Province Outstanding Research and Innovation Team in Higher Education Institutions(No.2022AH010024).
文摘The external residence time distribution(RTD)curve is extensively used to characterise fluid flow within the single-strand continuous casting tundish.Dead volume fraction determination typically relies on the external RTD curve to reveal macroscopic fluid flow behaviour.Based on the external RTD to effectively assess dead volume fractions and other fluid characteristics under conditions of internal non-uniform flow,an internal RTD was introduced.In a smooth pipe under laminar flow conditions,the dead region occupies 25%of the total volume,which is defined as the space between the pipe wall and a radius of 0.866 R0(where R0 is the radius of pipe).Under turbulent flow conditions,the dead region only occupies 0.38%of the reactor’s internal volume,spanning from the pipe wall to a radius of 0.00189 R0.The results obtained using the external RTD method are consistent with the theoretical analysis.Experimental trials involving water were conducted to examine the flow of molten steel within a five-strand tundish.Subsequently,an analysis approach employing internal RTD was employed to evaluate fluid mixing within a multi-flow continuous casting tundish.Using the internal RTD method,the analysis revealed that the whole dead zone volume fraction of the intermediate package decreased from 26.9%to 18.9%after the addition of the flow control device.The dead volume fraction can be accurately depicted by utilising the internal mean RTD function.The association between the internal RTD function and the external average RTD can be effectively employed to scrutinise the response curve of the tracer within a system exhibiting uneven flow distribution.
文摘Italy will host the 17th edition of ITMA, the world’s largest exhibition of textile machinery.It will be held at the Fiera Milano Rhoexhibition centre in Milan,from 12 to 19 November 2015.
文摘This paper analyzes some problems arising in determining the mails Whole Delivery Standard of Time Bound ( WDSTB ) at present, and further on the basis of the postal central office system currently in practice, puts forward the principle, reflection and the concrete approaches in determining the Delivery Standard of Time Bound ( DSTB ).
文摘When SAE-China participated in SAE In-ternational Congress for the first time seven years ago, there was only one member in the SAE-China delegation. While, ’98 SAE inter-national greeted the SAE-China larger delegation of more than 50 members, of whom about 40 members were from Chinese auto suppliers and the others from SAE-China, CAAM (China As-sociation of Automobile Manufacturers), univer-
文摘In our times, philosophy has been suffering from a spiritual crisis that takes the forms of the crisis of culture, the crisis of meaning, and the crisis of way of life. As the soul of culture, philosophy should contribute valuable responses to the problems of our times. Thus understood, this paper intends to analyze the concept of crisis in a phenomenological approach. The concept of crisis is concerned with the philosophical themes of time and death, and the crises of our times are primarily the crises of life-meaning and the life-world. Drawing sources from Husserl and other phenomenologists, as well as experiences from Chinese culture, I argue that a philosophy of crisis should find its point of departure from the crisis of philosophy.
