Atmospheric humic-like substances （HULIS） are not only an unresolved mixture of macro- organic compounds but also powerful chelating agents in atmospheric particulate matters （PMs）; impacting on both the propertie...Atmospheric humic-like substances （HULIS） are not only an unresolved mixture of macro- organic compounds but also powerful chelating agents in atmospheric particulate matters （PMs）; impacting on both the properties of aerosol particles and health effects by generating reactive oxygen spedes （ROS）. Currently, the interests of HULIS are intensively shifting to the investigations of HULIS-metal synergic effects and kinetics modeling studies, as well as the development of HULIS quantification, findings of possible HULIS sources and generation of ROS from HULIS. In light of HULIS studies, we comprehensively review the current knowledge of isolation and physicochemical characterization of HULIS from atmospheric samples as well as HULIS properties （hygroscopic, surface activity, and colloidal） and possible sources of HULIS. This review mainly highlights the generation of reactive oxygen species （ROS） from PMs, HULIS and transition metals, especially iron. This review also summarized the mechanism of iron-organic complexation and recent findings of OH formation from HULIS-metal complexes. This review will be helpful to carry out the modeling studies that concern with HULIS-transition metals and for further studies in the generation of ROS from HULIS-metal complexes,展开更多
The importance of foundry coating in improving the surface quality of castings cannot be over emphasized. The application of mould and core washes creates a high thermal integrity barrier between the metal and the mou...The importance of foundry coating in improving the surface quality of castings cannot be over emphasized. The application of mould and core washes creates a high thermal integrity barrier between the metal and the mould resulting in the reduction of the thermal shock experienced by the sand system. These thermal shock leads to series of surface defects such as veining/finning, metal penetration, burn-on/in, scab, rat tail, erosion etc. The use of coatings reduces the tendency of occurrence of these defects. However, the understanding of the coating, its components, characteristics and mechanism of action is important. In this review, a detailed description of these topics and examples are provided where necessary. A potential area of research in foundry coating development, using sol-gel process is suggested. The application of sol-gel technology in the development of foundry coatings is a novel approach.展开更多
基金the Natural Science Foundation of China under NSFC Grant No. 21477073, 41273127 for support to conduct this research
文摘Atmospheric humic-like substances （HULIS） are not only an unresolved mixture of macro- organic compounds but also powerful chelating agents in atmospheric particulate matters （PMs）; impacting on both the properties of aerosol particles and health effects by generating reactive oxygen spedes （ROS）. Currently, the interests of HULIS are intensively shifting to the investigations of HULIS-metal synergic effects and kinetics modeling studies, as well as the development of HULIS quantification, findings of possible HULIS sources and generation of ROS from HULIS. In light of HULIS studies, we comprehensively review the current knowledge of isolation and physicochemical characterization of HULIS from atmospheric samples as well as HULIS properties （hygroscopic, surface activity, and colloidal） and possible sources of HULIS. This review mainly highlights the generation of reactive oxygen species （ROS） from PMs, HULIS and transition metals, especially iron. This review also summarized the mechanism of iron-organic complexation and recent findings of OH formation from HULIS-metal complexes. This review will be helpful to carry out the modeling studies that concern with HULIS-transition metals and for further studies in the generation of ROS from HULIS-metal complexes,
文摘The importance of foundry coating in improving the surface quality of castings cannot be over emphasized. The application of mould and core washes creates a high thermal integrity barrier between the metal and the mould resulting in the reduction of the thermal shock experienced by the sand system. These thermal shock leads to series of surface defects such as veining/finning, metal penetration, burn-on/in, scab, rat tail, erosion etc. The use of coatings reduces the tendency of occurrence of these defects. However, the understanding of the coating, its components, characteristics and mechanism of action is important. In this review, a detailed description of these topics and examples are provided where necessary. A potential area of research in foundry coating development, using sol-gel process is suggested. The application of sol-gel technology in the development of foundry coatings is a novel approach.
