The original temporal clustering analysis (OTCA) is an effective technique for obtaining brain activation maps when the timing and location of the activation are completely unknown, but its deficiency of sensitivity i...The original temporal clustering analysis (OTCA) is an effective technique for obtaining brain activation maps when the timing and location of the activation are completely unknown, but its deficiency of sensitivity is exposed in processing brain activation signal which is relatively weak. The time slice analysis method based on OTCA is proposed considering the weakness of the functional magnetic resonance imaging (fMRI) signal of the rat model. By dividing the stimulation period into several time slices and analyzing each slice to detect the activated pixels respectively after the background removal, the sensitivity is significantly improved. The inhibitory response in the hypothalamus after glucose loading is detected successfully with this method in the experiment on rat. Combined with the OTCA method, the time slice analysis method based on OTCA is effective on detecting when, where and which type of response will happen after stimulation, even if the fMRI signal is weak.展开更多
The inclusions of Al in steels have great influence on the properties and the quality of steels.But there are some difficulties on the content determination of Al inclusions with accuracy and rapidity.Conventional qua...The inclusions of Al in steels have great influence on the properties and the quality of steels.But there are some difficulties on the content determination of Al inclusions with accuracy and rapidity.Conventional quantity analysis of stable inclusions is electrolysis method with the disadvantages of long analytical period,trivial operation and a little loss of some fine and instable oxides.The content of insoluble aluminum can be obtained by the subtraction between the content of total Al and acid soluble Al determined by chemical methods with the disadvantage of complicate procedure.Original position statistic distribution analysis(OPA) can be used for the determination of inclusions by collecting and discriminating the signals produced by single spark discharge in the way of no pre-sparking,scanning and emitting continuously.In this study the element of Al in some spectrum certified reference materials of carbon and medium or low-alloyed steels was analyzed by original opposition statistic distribution technique.Two quantitative mathematical models used by original position distribution analysis technology for the analysis of the content of Al inclusions have been investigated and been applied to the analysis of the content of Al inclusions in many kinds of spectrum certified reference materials and some medium and low-alloyed steel samples.The scope of application of the models and their limited conditions were discussed.It was found that the results calculated by OPA had great difference with the value by chemical method for some samples with the total content of Al above 0.2%.The reason is that some intensity of abnormal sparks have gone beyond the range of the largest intensity that can be determined by the instrument so that there is a certain deviation on the identification of abnormal sparks and the calculation of threshold value.It was found that the size distribution of Al inclusions had a great influence on the application of the two models.For most of certified reference materials for spectrum analysis and real steel samples the results of the content of Al in inclusions calculated by model 1 was satisfied and had good coincidence with the value of insoluble Al by chemical method. But for the samples with so many large inclusions of Al existed,the influence of intensity should be considered because the signal increase did not vary in the form of simple function.So model 2 was more suitable for the content calculation of Al in inclusions in this case.In order to choose suitable model to be used it is suggested that the size distribution of inclusions should be determined by OPA before content determination of Al in inclusions. The results of the content of Al inclusions calculated by the selected mathematical model were satisfied and had good coincidence with the value of insoluble Al obtained by the subtraction between the content of total Al and soluble Al determined by chemical methods when the content of total aluminum was below 0.2%.展开更多
The global sustained low oil prices have a significant impact on China's oil and gas industry system and the national energy security.This paper aims to find solutions in order to guarantee the smooth development ...The global sustained low oil prices have a significant impact on China's oil and gas industry system and the national energy security.This paper aims to find solutions in order to guarantee the smooth development of China's oil and gas industry system and its survival in such a severe environment.First,the origins of sustained low oil prices were analyzed.Then,based on those published data from IEA,government and some other authorities,this study focused on the development status,energy policies and the future developing trend of those main oil&gas producing countries.Investigations show that the low-price running is primarily contributed to the so-called oil and gas policies in the USA.It is predicted that national petroleum consumption will reach up to 6.0×10^(8) t(oil)&3300×10^(8) m^(3)(gas)in 2020 and 6.8×10^(8) t(oil)&5200×10^(8) m^(3)(gas)in 2030.For reducing the dependence on foreign oil and gas,the investment in the upstream of oil and gas industry should be maintained and scientific research should be intensified to ensure the smooth operation of the oil and gas production system.Considering China's national energy security strategy,the following suggestions were proposed herein.First,ensure that in China the yearly oil output reaches 2×10^(8) t,while natural gas yield will be expected to be up to 2700×10^(8) m^(3)in 2030,both of which should become the“bottom line”in the long term.Second,focus on the planning of upstream business with insistence on risk exploration investment,scientific and technological innovation and pilot area construction especially for low-permeability tight oil&gas,shale oil&gas reservoir development techniques.Third,encourage the in-depth reform and further growth especially in the three major state-owned oil&gas companies under adverse situations,and create more companies competent to offer overseas technical services by taking the opportunity of the“One Belt and One Road”policy.Finally,promote the new energy business and find solutions to turning those oil companies to integrated energy companies.展开更多
The chemical composition in a cross section of a high grade pipeline slab was measured point by point （in a scale of 1 μm） using original position statistic distribution analysis （OPA）. The result indicated that ...The chemical composition in a cross section of a high grade pipeline slab was measured point by point （in a scale of 1 μm） using original position statistic distribution analysis （OPA）. The result indicated that negative segregation strips of Si, Mn, Mo, Ni, Cr, Nb, Cu, Ti, and V exist in the two sides 24 mm away from the central line, with a width of 8-12 mm, Negative segregation inside the central line is more severe than that outside the central line, and the highest positive segregation of the elements appears closely by the inner sides of the negative segregation strips. No obvious negative segregation strip of S and P is found. Segregation of the elements in the central area is higher than that in the outer and inner arc areas. The segregation of C, Ti, S, and P is high and that of Cr, Cu, Si, and Mn is low in the slab.展开更多
基金the National Natural Science Foundation of China (30370432)
文摘The original temporal clustering analysis (OTCA) is an effective technique for obtaining brain activation maps when the timing and location of the activation are completely unknown, but its deficiency of sensitivity is exposed in processing brain activation signal which is relatively weak. The time slice analysis method based on OTCA is proposed considering the weakness of the functional magnetic resonance imaging (fMRI) signal of the rat model. By dividing the stimulation period into several time slices and analyzing each slice to detect the activated pixels respectively after the background removal, the sensitivity is significantly improved. The inhibitory response in the hypothalamus after glucose loading is detected successfully with this method in the experiment on rat. Combined with the OTCA method, the time slice analysis method based on OTCA is effective on detecting when, where and which type of response will happen after stimulation, even if the fMRI signal is weak.
文摘The inclusions of Al in steels have great influence on the properties and the quality of steels.But there are some difficulties on the content determination of Al inclusions with accuracy and rapidity.Conventional quantity analysis of stable inclusions is electrolysis method with the disadvantages of long analytical period,trivial operation and a little loss of some fine and instable oxides.The content of insoluble aluminum can be obtained by the subtraction between the content of total Al and acid soluble Al determined by chemical methods with the disadvantage of complicate procedure.Original position statistic distribution analysis(OPA) can be used for the determination of inclusions by collecting and discriminating the signals produced by single spark discharge in the way of no pre-sparking,scanning and emitting continuously.In this study the element of Al in some spectrum certified reference materials of carbon and medium or low-alloyed steels was analyzed by original opposition statistic distribution technique.Two quantitative mathematical models used by original position distribution analysis technology for the analysis of the content of Al inclusions have been investigated and been applied to the analysis of the content of Al inclusions in many kinds of spectrum certified reference materials and some medium and low-alloyed steel samples.The scope of application of the models and their limited conditions were discussed.It was found that the results calculated by OPA had great difference with the value by chemical method for some samples with the total content of Al above 0.2%.The reason is that some intensity of abnormal sparks have gone beyond the range of the largest intensity that can be determined by the instrument so that there is a certain deviation on the identification of abnormal sparks and the calculation of threshold value.It was found that the size distribution of Al inclusions had a great influence on the application of the two models.For most of certified reference materials for spectrum analysis and real steel samples the results of the content of Al in inclusions calculated by model 1 was satisfied and had good coincidence with the value of insoluble Al by chemical method. But for the samples with so many large inclusions of Al existed,the influence of intensity should be considered because the signal increase did not vary in the form of simple function.So model 2 was more suitable for the content calculation of Al in inclusions in this case.In order to choose suitable model to be used it is suggested that the size distribution of inclusions should be determined by OPA before content determination of Al in inclusions. The results of the content of Al inclusions calculated by the selected mathematical model were satisfied and had good coincidence with the value of insoluble Al obtained by the subtraction between the content of total Al and soluble Al determined by chemical methods when the content of total aluminum was below 0.2%.
基金Project supported by the National Basic Research Program of China(973 Program)“Basic Research on Efficient Development of Marine Shale Gas in Southern China”(Grant No.2013CB228000)the National Major Science and Technology Program during the“12th Five-Year Plan”“Key Techniques for Shale Gas Exploration and Development”(Grant No.2011ZX05018).
文摘The global sustained low oil prices have a significant impact on China's oil and gas industry system and the national energy security.This paper aims to find solutions in order to guarantee the smooth development of China's oil and gas industry system and its survival in such a severe environment.First,the origins of sustained low oil prices were analyzed.Then,based on those published data from IEA,government and some other authorities,this study focused on the development status,energy policies and the future developing trend of those main oil&gas producing countries.Investigations show that the low-price running is primarily contributed to the so-called oil and gas policies in the USA.It is predicted that national petroleum consumption will reach up to 6.0×10^(8) t(oil)&3300×10^(8) m^(3)(gas)in 2020 and 6.8×10^(8) t(oil)&5200×10^(8) m^(3)(gas)in 2030.For reducing the dependence on foreign oil and gas,the investment in the upstream of oil and gas industry should be maintained and scientific research should be intensified to ensure the smooth operation of the oil and gas production system.Considering China's national energy security strategy,the following suggestions were proposed herein.First,ensure that in China the yearly oil output reaches 2×10^(8) t,while natural gas yield will be expected to be up to 2700×10^(8) m^(3)in 2030,both of which should become the“bottom line”in the long term.Second,focus on the planning of upstream business with insistence on risk exploration investment,scientific and technological innovation and pilot area construction especially for low-permeability tight oil&gas,shale oil&gas reservoir development techniques.Third,encourage the in-depth reform and further growth especially in the three major state-owned oil&gas companies under adverse situations,and create more companies competent to offer overseas technical services by taking the opportunity of the“One Belt and One Road”policy.Finally,promote the new energy business and find solutions to turning those oil companies to integrated energy companies.
文摘The chemical composition in a cross section of a high grade pipeline slab was measured point by point （in a scale of 1 μm） using original position statistic distribution analysis （OPA）. The result indicated that negative segregation strips of Si, Mn, Mo, Ni, Cr, Nb, Cu, Ti, and V exist in the two sides 24 mm away from the central line, with a width of 8-12 mm, Negative segregation inside the central line is more severe than that outside the central line, and the highest positive segregation of the elements appears closely by the inner sides of the negative segregation strips. No obvious negative segregation strip of S and P is found. Segregation of the elements in the central area is higher than that in the outer and inner arc areas. The segregation of C, Ti, S, and P is high and that of Cr, Cu, Si, and Mn is low in the slab.
