Water footprint in a region is defined as the volume of water needed for the production of goods and services consumed by the local people, Ecosystem services are a kind of important services, so ecological water us...Water footprint in a region is defined as the volume of water needed for the production of goods and services consumed by the local people, Ecosystem services are a kind of important services, so ecological water use is one necessary component in water footprint. Water footprint is divided into green water footprint and blue water footprint but the former one is often ignored.In this paper waterJootprint includes blue water needed by agricultural irrigation, industrial and domestic water demand, and green water needed by crops, economic forests, livestock prochtcts, forestlalands and grasslands. The study calculates the footprint of the Jinghe River basin in 1990, 1995, 2000 and 2005 with quarto methods. Results of research show that water footprints reached 164.1 ×10^8m3, 175. 69 ×10^8m3 and 178. 45 ×10^8m3 respectively in 1990, 1995 and 2000 including that of ecological water use, but reached 77.68×10^8m3, 94.24×10^8m3, 92.92×10^8m3 and 111.36 ×10^8m3 respectively excluding that of ecological water use. Green water.footprint is much more than blue water footprint; thereby, green water plays an important role in economic development and ecological construction The dynamic change of water footprints shows that blue water use increases rapidly and that the ecological water use is occupied by economie and domestic water use. The change also shows that water use is transferred from primary industry to secondary industry In primary industry, it is transferred from crops farming to forestry, and animal agriculture. The factors impelling the change include development anticipation on econonomy; government policies, readjustment of the industrial structure, population growth, the raise of urbanization level, and structurul change of consumption, low level of waler-saving and poor ability of waste water treatment.With blue water use per unit, green water use per unit, blue water use structure and green water use structure, we analyzed the difference of the six ecologieal function districts of the Jinghe River basin. Future ecological construction may influence on blue water use of District V and District Ⅵ at middle and lower reaches. At last some suggestions are given for effective water resouree use.展开更多
A novel polysaccharide-bonded abrasive tool is proposed for the green machining of single-crystal sapphires.The prescription and manufacturing process of the proposed tool is designed,and the gelation property of poly...A novel polysaccharide-bonded abrasive tool is proposed for the green machining of single-crystal sapphires.The prescription and manufacturing process of the proposed tool is designed,and the gelation property of polysaccharide by microwave treatment is investigated.Abrasive tool samples are fabricated,and a machining experiment on a single-crystal sapphire is performed.It is found that the crystallinity of polysaccharide gel decreases as the proportion of cross-linked polysaccharide increases.Abrasive tool samples with cross-linked polysaccharide present higher surface hardness.With the new abrasive tool,the surface quality of sapphire wafer can be significantly improved.This new tool with an abrasive to binder ratio of 2∶1 attains a material removal rate of 0.68μm/min.It is found that increasing the abrasive to binder ratio leads to better self-dressing performance but worse material removal ability and greater loss of abrasive tool materials.The validity of polysaccharide as an abrasive tool binder is preliminarily verified.展开更多
文摘Water footprint in a region is defined as the volume of water needed for the production of goods and services consumed by the local people, Ecosystem services are a kind of important services, so ecological water use is one necessary component in water footprint. Water footprint is divided into green water footprint and blue water footprint but the former one is often ignored.In this paper waterJootprint includes blue water needed by agricultural irrigation, industrial and domestic water demand, and green water needed by crops, economic forests, livestock prochtcts, forestlalands and grasslands. The study calculates the footprint of the Jinghe River basin in 1990, 1995, 2000 and 2005 with quarto methods. Results of research show that water footprints reached 164.1 ×10^8m3, 175. 69 ×10^8m3 and 178. 45 ×10^8m3 respectively in 1990, 1995 and 2000 including that of ecological water use, but reached 77.68×10^8m3, 94.24×10^8m3, 92.92×10^8m3 and 111.36 ×10^8m3 respectively excluding that of ecological water use. Green water.footprint is much more than blue water footprint; thereby, green water plays an important role in economic development and ecological construction The dynamic change of water footprints shows that blue water use increases rapidly and that the ecological water use is occupied by economie and domestic water use. The change also shows that water use is transferred from primary industry to secondary industry In primary industry, it is transferred from crops farming to forestry, and animal agriculture. The factors impelling the change include development anticipation on econonomy; government policies, readjustment of the industrial structure, population growth, the raise of urbanization level, and structurul change of consumption, low level of waler-saving and poor ability of waste water treatment.With blue water use per unit, green water use per unit, blue water use structure and green water use structure, we analyzed the difference of the six ecologieal function districts of the Jinghe River basin. Future ecological construction may influence on blue water use of District V and District Ⅵ at middle and lower reaches. At last some suggestions are given for effective water resouree use.
基金supported by the National Science Foundation of China (Nos.51605129,51705330)China Postdoctoral Science Foundation (No. 2015M581977)Anhui Provincial Natural Science Foundation(No.1708085ME109)。
文摘A novel polysaccharide-bonded abrasive tool is proposed for the green machining of single-crystal sapphires.The prescription and manufacturing process of the proposed tool is designed,and the gelation property of polysaccharide by microwave treatment is investigated.Abrasive tool samples are fabricated,and a machining experiment on a single-crystal sapphire is performed.It is found that the crystallinity of polysaccharide gel decreases as the proportion of cross-linked polysaccharide increases.Abrasive tool samples with cross-linked polysaccharide present higher surface hardness.With the new abrasive tool,the surface quality of sapphire wafer can be significantly improved.This new tool with an abrasive to binder ratio of 2∶1 attains a material removal rate of 0.68μm/min.It is found that increasing the abrasive to binder ratio leads to better self-dressing performance but worse material removal ability and greater loss of abrasive tool materials.The validity of polysaccharide as an abrasive tool binder is preliminarily verified.
