This paper presents the long-term climate changes of significant wave height(Hs) in 1958–2001 over the entire global ocean using the 45-year European Centre for Medium-Range Weather Forecasts(ECMWF) Reanalysis(ERA-40...This paper presents the long-term climate changes of significant wave height(Hs) in 1958–2001 over the entire global ocean using the 45-year European Centre for Medium-Range Weather Forecasts(ECMWF) Reanalysis(ERA-40) wave data. The linear trends in Hs and regional and seasonal differences of the linear trends for Hs were calculated. Results show that the Hs exhibits a significant increasing trend of about 4.6 cm decade-1 in the global ocean as a whole over the last 44 years. The Hs changes slowly during the periods 1958–1974 and 1980–1991, while it increases consistently during the periods 1975–1980 and 1995–1998. The Hs reaches its lowest magnitude in 1975, with annual average wave height about 2 m. In 1992, the Hs has the maximum value of nearly 2.60 m. The Hs in most ocean waters has a significant increasing trend of 2–14 cm decade-1 over the last 44 years. The linear trend exhibits great regional differences. Areas with strong increasing trend of Hs are mainly distributed in the westerlies of the southern Hemisphere and the northern Hemisphere. Only some small areas show obvious decreasing in Hs. The long-term trend of Hs in DJF(December, January, February) and MAM(March, April, May) is much more stronger than that in JJA(June, July, August) and SON(September, October, November). The linear trends of the Hs in different areas are different in different seasons; for instance, the increasing trend of Hs in the westerlies of the Pacific Ocean mainly appears in MAM and DJF.展开更多
Factures caused by deformation and destruction of bedrocks over coal seams can easily lead to water flooding(inrush)in mines,a threat to safety production.Fractures with high hydraulic conductivity are good watercours...Factures caused by deformation and destruction of bedrocks over coal seams can easily lead to water flooding(inrush)in mines,a threat to safety production.Fractures with high hydraulic conductivity are good watercourses as well as passages for inrush in mines and tunnels.An accurate height prediction of water flowing fractured zones is a key issue in today's mine water prevention and control.The theory of leveraging BP artificial neural network in height prediction of water flowing fractured zones is analysed and applied in Qianjiaying Mine as an example in this paper.Per the comparison with traditional calculation results,the BP artificial neural network better reflects the geological conditions of the research mine areas and produces more objective,accurate and reasonable results,which can be applied to predict the height of water flowing fractured zones.展开更多
This article offers an overview of crop production in Wengyuan County:the growing area of rice is the biggest followed by sugarcane and the growing area of mulberry,Sanhua plum and Jiuxian peach is small;the annual ou...This article offers an overview of crop production in Wengyuan County:the growing area of rice is the biggest followed by sugarcane and the growing area of mulberry,Sanhua plum and Jiuxian peach is small;the annual output of sugarcane is the biggest followed by rice,the annual output of mulberry ranks NO.3,and the output of Sanhua plum and Jiuxian peach is the lowest,but the annual output of them is very close.In accordance with evaluation indicator system concerning explicit dominance of production and development of crops,coupled with data analysis,we determine the explicit dominance of the main crops in Wengyuan County.The results show that the normalized explicit dominance of rice,sugarcane,mulberry,Sanhua plum and Jiuxian peach in Wengyuan County is 0.23,0.94,0.33,0.22 and 0.46,respectively;in Wengyuan County,the sugarcane is fit to expand the scale,the mulberry and Jiuxian peach are relatively fit to expand the scale,and the rice and Sanhua plum are not fit to expand the scale.展开更多
基金supported by the National Ky Basic Research Development Program(Grant Nos.2015CB453200,2013CB956200,2012CB957803,2010CB950400)the National Natural Science Foundation of China(Grant Nos.41430426,41490642,41275086,41475070)
文摘This paper presents the long-term climate changes of significant wave height(Hs) in 1958–2001 over the entire global ocean using the 45-year European Centre for Medium-Range Weather Forecasts(ECMWF) Reanalysis(ERA-40) wave data. The linear trends in Hs and regional and seasonal differences of the linear trends for Hs were calculated. Results show that the Hs exhibits a significant increasing trend of about 4.6 cm decade-1 in the global ocean as a whole over the last 44 years. The Hs changes slowly during the periods 1958–1974 and 1980–1991, while it increases consistently during the periods 1975–1980 and 1995–1998. The Hs reaches its lowest magnitude in 1975, with annual average wave height about 2 m. In 1992, the Hs has the maximum value of nearly 2.60 m. The Hs in most ocean waters has a significant increasing trend of 2–14 cm decade-1 over the last 44 years. The linear trend exhibits great regional differences. Areas with strong increasing trend of Hs are mainly distributed in the westerlies of the southern Hemisphere and the northern Hemisphere. Only some small areas show obvious decreasing in Hs. The long-term trend of Hs in DJF(December, January, February) and MAM(March, April, May) is much more stronger than that in JJA(June, July, August) and SON(September, October, November). The linear trends of the Hs in different areas are different in different seasons; for instance, the increasing trend of Hs in the westerlies of the Pacific Ocean mainly appears in MAM and DJF.
基金funded by Royalty and Price of the Mining Right of the Ministry of Finance and the Ministry of Land and Resources in 2012 ([2012]145)
文摘Factures caused by deformation and destruction of bedrocks over coal seams can easily lead to water flooding(inrush)in mines,a threat to safety production.Fractures with high hydraulic conductivity are good watercourses as well as passages for inrush in mines and tunnels.An accurate height prediction of water flowing fractured zones is a key issue in today's mine water prevention and control.The theory of leveraging BP artificial neural network in height prediction of water flowing fractured zones is analysed and applied in Qianjiaying Mine as an example in this paper.Per the comparison with traditional calculation results,the BP artificial neural network better reflects the geological conditions of the research mine areas and produces more objective,accurate and reasonable results,which can be applied to predict the height of water flowing fractured zones.
文摘This article offers an overview of crop production in Wengyuan County:the growing area of rice is the biggest followed by sugarcane and the growing area of mulberry,Sanhua plum and Jiuxian peach is small;the annual output of sugarcane is the biggest followed by rice,the annual output of mulberry ranks NO.3,and the output of Sanhua plum and Jiuxian peach is the lowest,but the annual output of them is very close.In accordance with evaluation indicator system concerning explicit dominance of production and development of crops,coupled with data analysis,we determine the explicit dominance of the main crops in Wengyuan County.The results show that the normalized explicit dominance of rice,sugarcane,mulberry,Sanhua plum and Jiuxian peach in Wengyuan County is 0.23,0.94,0.33,0.22 and 0.46,respectively;in Wengyuan County,the sugarcane is fit to expand the scale,the mulberry and Jiuxian peach are relatively fit to expand the scale,and the rice and Sanhua plum are not fit to expand the scale.
