Using the inner-surface of polysulfone hollow fiber ultrafiltration membranes as grafted layer, the method of gas-initiation and liquid-polymerization has been studied, which aimed to adjust the diameter of the pores ...Using the inner-surface of polysulfone hollow fiber ultrafiltration membranes as grafted layer, the method of gas-initiation and liquid-polymerization has been studied, which aimed to adjust the diameter of the pores in the membranes. The degree of polymerization varied with the changes of the parameters, such as irradiation time, monomer concentration, temperature and time of polymerization and so on. The results indicated that using benzophenone(BP) which is in a gaseous condition as photo-initiator, acrylamide as graft monomer, the polyacrylamide chain was grafted on the surface of membranes. After the surface membrane being modified, the water flux and retention altered,and thus it can be seen that the diameter of the pores in the membrane was altered. These experiments contribute to finding a new way to produce the hollow fiber membrane with the small pore size and are extraordinarily worth developing and studying.展开更多
Concrete construction technology is a common technical form in construction engineering. Concrete construction in architectural engineering is professional and complex. Because it is easily restricted by other factors...Concrete construction technology is a common technical form in construction engineering. Concrete construction in architectural engineering is professional and complex. Because it is easily restricted by other factors, only through effective and reasonable methods, continuous improvement and optimization of concrete structure and construction technology, and strengthening of comprehensive and strict construction control can the construction quality and efficiency of construction projects be improved. According to the definition and characteristics of concrete structures, this paper discusses the application methods and quality control points of concrete construction technology from the aspects of concrete cracks and pouring volume, and explores methods and strategies with a higher degree of implementation to improve the quality of concrete structures. Therefore, this paper will mainly discuss the discussion of concrete construction technology in my country's construction engineering.展开更多
基金The Natural Science Foundation of Beijing(No. 2021002) the National Basic Research Priorties Programme(No. 2003CCA02500)
文摘Using the inner-surface of polysulfone hollow fiber ultrafiltration membranes as grafted layer, the method of gas-initiation and liquid-polymerization has been studied, which aimed to adjust the diameter of the pores in the membranes. The degree of polymerization varied with the changes of the parameters, such as irradiation time, monomer concentration, temperature and time of polymerization and so on. The results indicated that using benzophenone(BP) which is in a gaseous condition as photo-initiator, acrylamide as graft monomer, the polyacrylamide chain was grafted on the surface of membranes. After the surface membrane being modified, the water flux and retention altered,and thus it can be seen that the diameter of the pores in the membrane was altered. These experiments contribute to finding a new way to produce the hollow fiber membrane with the small pore size and are extraordinarily worth developing and studying.
文摘Concrete construction technology is a common technical form in construction engineering. Concrete construction in architectural engineering is professional and complex. Because it is easily restricted by other factors, only through effective and reasonable methods, continuous improvement and optimization of concrete structure and construction technology, and strengthening of comprehensive and strict construction control can the construction quality and efficiency of construction projects be improved. According to the definition and characteristics of concrete structures, this paper discusses the application methods and quality control points of concrete construction technology from the aspects of concrete cracks and pouring volume, and explores methods and strategies with a higher degree of implementation to improve the quality of concrete structures. Therefore, this paper will mainly discuss the discussion of concrete construction technology in my country's construction engineering.
