In this paper,based on the material flux analysis model(MFA) and its corresponding theories and algorithms of "virtual land" virtual land contents of five primary agricultural products are calculated and"Virtual ...In this paper,based on the material flux analysis model(MFA) and its corresponding theories and algorithms of "virtual land" virtual land contents of five primary agricultural products are calculated and"Virtual land trade"hidden in those imported and exported products are also obtained through analyzing the primary agricultural product trade between China and ASEAN. In the process of calculationl following the thought of Changing agricultural products to "Virtual land trade"land content, trade condition and spatiai distribution of agricultural products Were integratedly considered. indicate that China exported 73;057 km^2 of virtual land area to ASEAN by tea, vegetables; maize and grain, ASEAN exported: 57.332 km^2 to China by natural rubber from 2002 to 2005. It obvious; that china has lost 15,725 km^2 arable land through agricultural product trade, Additionally, in order to process: of calculation Virtual land trade, Thailand taker as an example to analyze its international trade of rice and Wheat from 1991 to 2005 and Calculate their "Virtual land trade" 2001 through 2005. According to and calculation, it is not difficult to conclude that "Virtual land trade" very important and could be used for China to guide agricultural export or import Structure and maintain Sustainable use of land resources.展开更多
The attenuation of prestack internal multiples based on virtual seismic events is computationally costly and hinders seismic data processing. We propose a multiples attenuation method for poststack seismic data by app...The attenuation of prestack internal multiples based on virtual seismic events is computationally costly and hinders seismic data processing. We propose a multiples attenuation method for poststack seismic data by approximating conventional virtual events. The proposed method is iterative. The proposed method is tested using 2D synthetic and the field poststack seismic datasets. Compared with the conventional virtual events method, the proposed method does not require data regularization and offers higher computation efficiency. The method requires to know the travel time of the primary reflection waves. The results of the application to 2D field datasets suggest that the proposed method attenuates the internal multiples while highlighting the deep primaries.展开更多
文摘In this paper,based on the material flux analysis model(MFA) and its corresponding theories and algorithms of "virtual land" virtual land contents of five primary agricultural products are calculated and"Virtual land trade"hidden in those imported and exported products are also obtained through analyzing the primary agricultural product trade between China and ASEAN. In the process of calculationl following the thought of Changing agricultural products to "Virtual land trade"land content, trade condition and spatiai distribution of agricultural products Were integratedly considered. indicate that China exported 73;057 km^2 of virtual land area to ASEAN by tea, vegetables; maize and grain, ASEAN exported: 57.332 km^2 to China by natural rubber from 2002 to 2005. It obvious; that china has lost 15,725 km^2 arable land through agricultural product trade, Additionally, in order to process: of calculation Virtual land trade, Thailand taker as an example to analyze its international trade of rice and Wheat from 1991 to 2005 and Calculate their "Virtual land trade" 2001 through 2005. According to and calculation, it is not difficult to conclude that "Virtual land trade" very important and could be used for China to guide agricultural export or import Structure and maintain Sustainable use of land resources.
基金supported by the National Natural Science Foundation of China(No.41674122)National Science and Technology Major Project of China(No.2016ZX05004003)National Basic Research Program of China(No.2013CB228602)
文摘The attenuation of prestack internal multiples based on virtual seismic events is computationally costly and hinders seismic data processing. We propose a multiples attenuation method for poststack seismic data by approximating conventional virtual events. The proposed method is iterative. The proposed method is tested using 2D synthetic and the field poststack seismic datasets. Compared with the conventional virtual events method, the proposed method does not require data regularization and offers higher computation efficiency. The method requires to know the travel time of the primary reflection waves. The results of the application to 2D field datasets suggest that the proposed method attenuates the internal multiples while highlighting the deep primaries.