The unconventional oil and gas resources presented in oil shales have meant these potential sources of hydrocarbons, which has become a research focus. China contains abundant oil shale resources, ranking fourth in th...The unconventional oil and gas resources presented in oil shales have meant these potential sources of hydrocarbons, which has become a research focus. China contains abundant oil shale resources, ranking fourth in the world, with ca. 7 254.48 x 108 t within 24 provinces, including 48 basins and 81 oil shale deposits. A- bout 48% of the total oil shale resources are concentrated in the eastern resource region, with a further 22% in the central resource region. 65 % of the total quantity of oil shale resources is present at depths of 0-500 m, with 17% of the total resources being defined as high-quality oil shales yielding more than 10% oil by weight. Chinese oil shale resources are generally hosted by Mesozoic sediments that account for 78% of the total re- sources. In terms of the geographical distribution of these resources, some 45% are located in plain regions, and different oil shale basins have various characteristics. The oil shale resources in China represent a highly prospective future source of hydrocarbons. These resources having potential use not only in power generation and oil refining but also in agriculture, metal and chemical productions, and environmental protection.展开更多
The computational uncertainty principle states that the numerical computation of nonlinear ordinary differential equations（ODEs） should use appropriately sized time steps to obtain reliable solutions.However,the int...The computational uncertainty principle states that the numerical computation of nonlinear ordinary differential equations（ODEs） should use appropriately sized time steps to obtain reliable solutions.However,the interval of effective step size（IES） has not been thoroughly explored theoretically.In this paper,by using a general estimation for the total error of the numerical solutions of ODEs,a method is proposed for determining an approximate IES by translating the functions for truncation and rounding errors.It also illustrates this process with an example.Moreover,the relationship between the IES and its approximation is found,and the relative error of the approximation with respect to the IES is given.In addition,variation in the IES with increasing integration time is studied,which can provide an explanation for the observed numerical results.The findings contribute to computational step-size choice for reliable numerical solutions.展开更多
基金Supported by the Ministry of Education of China Grants(OSR-1-03)
文摘The unconventional oil and gas resources presented in oil shales have meant these potential sources of hydrocarbons, which has become a research focus. China contains abundant oil shale resources, ranking fourth in the world, with ca. 7 254.48 x 108 t within 24 provinces, including 48 basins and 81 oil shale deposits. A- bout 48% of the total oil shale resources are concentrated in the eastern resource region, with a further 22% in the central resource region. 65 % of the total quantity of oil shale resources is present at depths of 0-500 m, with 17% of the total resources being defined as high-quality oil shales yielding more than 10% oil by weight. Chinese oil shale resources are generally hosted by Mesozoic sediments that account for 78% of the total re- sources. In terms of the geographical distribution of these resources, some 45% are located in plain regions, and different oil shale basins have various characteristics. The oil shale resources in China represent a highly prospective future source of hydrocarbons. These resources having potential use not only in power generation and oil refining but also in agriculture, metal and chemical productions, and environmental protection.
基金supported by the National Natural Science Foundation of China[grant numbers 41375110,11471244]
文摘The computational uncertainty principle states that the numerical computation of nonlinear ordinary differential equations（ODEs） should use appropriately sized time steps to obtain reliable solutions.However,the interval of effective step size（IES） has not been thoroughly explored theoretically.In this paper,by using a general estimation for the total error of the numerical solutions of ODEs,a method is proposed for determining an approximate IES by translating the functions for truncation and rounding errors.It also illustrates this process with an example.Moreover,the relationship between the IES and its approximation is found,and the relative error of the approximation with respect to the IES is given.In addition,variation in the IES with increasing integration time is studied,which can provide an explanation for the observed numerical results.The findings contribute to computational step-size choice for reliable numerical solutions.
