Thickener formulation plays a significant role in the performance characteristics of grease.The polyurea greases(PUGs)were synthesized using mineral oil(500SN)as the base oil,and by regulating the reaction of diphenyl...Thickener formulation plays a significant role in the performance characteristics of grease.The polyurea greases(PUGs)were synthesized using mineral oil(500SN)as the base oil,and by regulating the reaction of diphenylmethane diisocyanate(MDI)and different organic amines.The as‐prepared PUGs from the reaction of MDI and cyclohexylamine/p‐toluidine exhibit the optimum physicochemical and friction‐wear properties,confirming that the regulation of thickener formulation can improve the performance characteristics of grease,including friction reduction,wear,corrosion resistance,and load‐carrying capacity.The anticorrosion and lubrication properties of as‐prepared PUGs depend on good sealing functions and a boundary lubrication film(synergy of grease‐film and tribo‐chemical reaction film),as well as their chemical components and structure.展开更多
Vernacular building is the building for ordinary people,constrained by the practicalities of environmental conditions and physical materials,and influenced by traditional culture,but not mediated by professional...Vernacular building is the building for ordinary people,constrained by the practicalities of environmental conditions and physical materials,and influenced by traditional culture,but not mediated by professional architects and engineers.Combinations of earth and timber,such as wattle and daub,are found in the vernacular in almost every part of the world,but are a source of great confusion to archaeologists and scholars.Archaeologists are misled by the remains,in which the earth may have survived but the timber usually does not.Techniques such as Lehmwickel are never recognised in archaeological work.There is no common system of naming or classification,and English speakers regularly describe any combination of earth and timber in walling as‘wattle and daub’.Many of these techniques have been changed by the impact of modern technology,notably pole and pug construction(which is often confused with wattle and daub,though it is quite different in principle);this is essentially a 19^(th) century development because it relies upon plentiful and cheap nails.The purpose of this paper is to establish a common terminology in English,and where possible in other relevant languages,so that misinterpretations are avoided and scholarship can proceed on an orderly basis.展开更多
文摘Thickener formulation plays a significant role in the performance characteristics of grease.The polyurea greases(PUGs)were synthesized using mineral oil(500SN)as the base oil,and by regulating the reaction of diphenylmethane diisocyanate(MDI)and different organic amines.The as‐prepared PUGs from the reaction of MDI and cyclohexylamine/p‐toluidine exhibit the optimum physicochemical and friction‐wear properties,confirming that the regulation of thickener formulation can improve the performance characteristics of grease,including friction reduction,wear,corrosion resistance,and load‐carrying capacity.The anticorrosion and lubrication properties of as‐prepared PUGs depend on good sealing functions and a boundary lubrication film(synergy of grease‐film and tribo‐chemical reaction film),as well as their chemical components and structure.
文摘Vernacular building is the building for ordinary people,constrained by the practicalities of environmental conditions and physical materials,and influenced by traditional culture,but not mediated by professional architects and engineers.Combinations of earth and timber,such as wattle and daub,are found in the vernacular in almost every part of the world,but are a source of great confusion to archaeologists and scholars.Archaeologists are misled by the remains,in which the earth may have survived but the timber usually does not.Techniques such as Lehmwickel are never recognised in archaeological work.There is no common system of naming or classification,and English speakers regularly describe any combination of earth and timber in walling as‘wattle and daub’.Many of these techniques have been changed by the impact of modern technology,notably pole and pug construction(which is often confused with wattle and daub,though it is quite different in principle);this is essentially a 19^(th) century development because it relies upon plentiful and cheap nails.The purpose of this paper is to establish a common terminology in English,and where possible in other relevant languages,so that misinterpretations are avoided and scholarship can proceed on an orderly basis.
