The size distribution of a muck pile depends not on only the blasting standard but also on the mechanical properties,joint system,and crack density of the rock mass. As,the cracks in the rock masses are especially hea...The size distribution of a muck pile depends not on only the blasting standard but also on the mechanical properties,joint system,and crack density of the rock mass. As,the cracks in the rock masses are especially heavily developed at the limestone quar- ries in Japan,they,along with the joints,have a large impact on the effects of blasting, such as the size of the muck pile.Therefore,if the joint system and/or crack density in a rock mass can be determined and quantitatively evaluated,the blasting operation can be conducted more effectively,efficiently and safely.However,guidelines for designing ap- propriate blasting standards based on the rock mass conditions have not yet been scien- tifically developed.Therefore,blasting tests were conducted on different mines and faces, under different geological conditions and blasting standards,in order to determine the im- pacts of each factor on the effects of blasting.Summarized the results of a series of blast- ing tests and described the impacts of geological conditions on the size of the muck pile produced by blast.展开更多
The Chedaren ravine belongs to high-prone areas of debris flow in Jilin Province, which threaten the local people＇ s life and security seriously. The authors used the residual correction theory to amend the GM （ 1,...The Chedaren ravine belongs to high-prone areas of debris flow in Jilin Province, which threaten the local people＇ s life and security seriously. The authors used the residual correction theory to amend the GM （ 1, 1 ） model and forecast annual precipitation in disaster year of the Chedaren ravine ; it provides scientific foundation for early warning of debris flow disaster in the rainy season based on weather forecast. The prediction resuits show that annual precipitation is 724.7 mm in 2009 ; the region will probably occur large-scale debris flow during the rainy season.展开更多
Maintaining soil phosphorus （P） at adequate levels for plant growth requires assessing how the long-term P balance （viz., the difference between P inputs and outputs） results in changes in soil test P. The hypothe...Maintaining soil phosphorus （P） at adequate levels for plant growth requires assessing how the long-term P balance （viz., the difference between P inputs and outputs） results in changes in soil test P. The hypothesis that routinely measured soil properties can help predict the conversion factor of P balance into Olsen P was tested at 39 sites in agricultural areas of the Mediterranean region in Spair~. A set of soil samples from each site was analyzed for Olsen P, inorganic P （P extracted using 0.5 mol L-1 H2SO4）, pseudototal P （P extracted using 0.5 mol L-1 H2SO4 following ignition at 550 ~C）, and organic P （the difference between pseudototal P and inorganic P）. Organic and Olsen P were uncorrelated in most of the 39 soil sets, which suggests that organic P content changed little with P inputs and outputs. The slopes of the regression lines of Olsen P against pseudototal and inorganic P, which were used as two different measures of the conversion factor, ranged widely （from 0.03 to 0.25 approximately）, with their average values （about 0.10） being similar to those found in long-term experiments conducted in temperate areas. Neither conversion factor was significantly correlated with any routinely measured soil property; however, the conversion factor for inorganic P was significantly lower for calcareous soils than for noncalcareous soils. Our negative results suggest the need to isolate the influence of soil properties from that of management systems and environmental factors relating to P dynamics in future studies.展开更多
文摘The size distribution of a muck pile depends not on only the blasting standard but also on the mechanical properties,joint system,and crack density of the rock mass. As,the cracks in the rock masses are especially heavily developed at the limestone quar- ries in Japan,they,along with the joints,have a large impact on the effects of blasting, such as the size of the muck pile.Therefore,if the joint system and/or crack density in a rock mass can be determined and quantitatively evaluated,the blasting operation can be conducted more effectively,efficiently and safely.However,guidelines for designing ap- propriate blasting standards based on the rock mass conditions have not yet been scien- tifically developed.Therefore,blasting tests were conducted on different mines and faces, under different geological conditions and blasting standards,in order to determine the im- pacts of each factor on the effects of blasting.Summarized the results of a series of blast- ing tests and described the impacts of geological conditions on the size of the muck pile produced by blast.
文摘The Chedaren ravine belongs to high-prone areas of debris flow in Jilin Province, which threaten the local people＇ s life and security seriously. The authors used the residual correction theory to amend the GM （ 1, 1 ） model and forecast annual precipitation in disaster year of the Chedaren ravine ; it provides scientific foundation for early warning of debris flow disaster in the rainy season based on weather forecast. The prediction resuits show that annual precipitation is 724.7 mm in 2009 ; the region will probably occur large-scale debris flow during the rainy season.
基金funded by the former Spanish Ministry of Science and Innovation(No.AGL201129893-C02-02)the European Regional Development Fund
文摘Maintaining soil phosphorus （P） at adequate levels for plant growth requires assessing how the long-term P balance （viz., the difference between P inputs and outputs） results in changes in soil test P. The hypothesis that routinely measured soil properties can help predict the conversion factor of P balance into Olsen P was tested at 39 sites in agricultural areas of the Mediterranean region in Spair~. A set of soil samples from each site was analyzed for Olsen P, inorganic P （P extracted using 0.5 mol L-1 H2SO4）, pseudototal P （P extracted using 0.5 mol L-1 H2SO4 following ignition at 550 ~C）, and organic P （the difference between pseudototal P and inorganic P）. Organic and Olsen P were uncorrelated in most of the 39 soil sets, which suggests that organic P content changed little with P inputs and outputs. The slopes of the regression lines of Olsen P against pseudototal and inorganic P, which were used as two different measures of the conversion factor, ranged widely （from 0.03 to 0.25 approximately）, with their average values （about 0.10） being similar to those found in long-term experiments conducted in temperate areas. Neither conversion factor was significantly correlated with any routinely measured soil property; however, the conversion factor for inorganic P was significantly lower for calcareous soils than for noncalcareous soils. Our negative results suggest the need to isolate the influence of soil properties from that of management systems and environmental factors relating to P dynamics in future studies.
