By using cross-section data on consumption structure of rural residents in Gansu Province in 2007 and 2008,this paper adopts ELES model to conduct empirical analysis on consumption structure of rural residents in Gans...By using cross-section data on consumption structure of rural residents in Gansu Province in 2007 and 2008,this paper adopts ELES model to conduct empirical analysis on consumption structure of rural residents in Gansu Province.It indicates that in the current consumption structure of rural residents in Gansu Province,food expenditure is still at the most important and basic level;the overall consumption level of rural residents in Gansu Province is not high;at present,the consumption of rural residents in Gansu Province still hinges in a large measure on income,vulnerable to the price fluctuation.Consequently,increasing farmers' income and stabilizing the level of commodity price,turns out to be a foundation as well as an important approach to improve consumption structure of rural residents in Gansu Province.展开更多
SEDEX-type lead-zinc deposits in the southern belt of the Xicheng Devonian basin, Gansu Province has been already identified. However, the sedimentary environment of the limestone and philite of the Xihanshui Group wi...SEDEX-type lead-zinc deposits in the southern belt of the Xicheng Devonian basin, Gansu Province has been already identified. However, the sedimentary environment of the limestone and philite of the Xihanshui Group within which the lead-zinc deposits occur is littoral and shallow sea. This is different from those in the northern belt such as the Changba-Lijiagou lead-zinc deposits, which were formed in deep sea. The reef and bioclastic limestone are widespread in the southern belt. Particularly they are associated with lead-zinc ores and there are no striae and banding but massive or disseminated structures. It is discovered that the black chimney consists of sphalerite, ankerite, pyrite and galena, in which black, coarse and radial sphalerite occurs as irregularly veins or cylindricality with a width of 10-40 cm in the center, and it is surround by fine ankerite and minor celestite with ribbon structure. The immediate wall rock of the chimney, reef limestone, was unaltered and the outside reef and bioclastic limestone were intensively silicified. Those silicified reef and bioclastic limestone host disseminated lead-zinc ores of the Luoba and Bijiashan type. It is concluded that the exhalative system occurred in a shallow sea in the Givetian of the middle Devonian. Brine is boiled due to low pressure, and a great deal of lead and zinc was dispersed in the interface between the limestone and phyllite and formed a source bed. In the Triassic period, meta-hydrothermal fluids leached and extracted metals from the source bed, and then moved and mineralized in open space such as arches and inverse limbs of anticlines, and formed massive and vein ores such as the Jianyagou and Dengjiashan type deposits.展开更多
文摘By using cross-section data on consumption structure of rural residents in Gansu Province in 2007 and 2008,this paper adopts ELES model to conduct empirical analysis on consumption structure of rural residents in Gansu Province.It indicates that in the current consumption structure of rural residents in Gansu Province,food expenditure is still at the most important and basic level;the overall consumption level of rural residents in Gansu Province is not high;at present,the consumption of rural residents in Gansu Province still hinges in a large measure on income,vulnerable to the price fluctuation.Consequently,increasing farmers' income and stabilizing the level of commodity price,turns out to be a foundation as well as an important approach to improve consumption structure of rural residents in Gansu Province.
文摘SEDEX-type lead-zinc deposits in the southern belt of the Xicheng Devonian basin, Gansu Province has been already identified. However, the sedimentary environment of the limestone and philite of the Xihanshui Group within which the lead-zinc deposits occur is littoral and shallow sea. This is different from those in the northern belt such as the Changba-Lijiagou lead-zinc deposits, which were formed in deep sea. The reef and bioclastic limestone are widespread in the southern belt. Particularly they are associated with lead-zinc ores and there are no striae and banding but massive or disseminated structures. It is discovered that the black chimney consists of sphalerite, ankerite, pyrite and galena, in which black, coarse and radial sphalerite occurs as irregularly veins or cylindricality with a width of 10-40 cm in the center, and it is surround by fine ankerite and minor celestite with ribbon structure. The immediate wall rock of the chimney, reef limestone, was unaltered and the outside reef and bioclastic limestone were intensively silicified. Those silicified reef and bioclastic limestone host disseminated lead-zinc ores of the Luoba and Bijiashan type. It is concluded that the exhalative system occurred in a shallow sea in the Givetian of the middle Devonian. Brine is boiled due to low pressure, and a great deal of lead and zinc was dispersed in the interface between the limestone and phyllite and formed a source bed. In the Triassic period, meta-hydrothermal fluids leached and extracted metals from the source bed, and then moved and mineralized in open space such as arches and inverse limbs of anticlines, and formed massive and vein ores such as the Jianyagou and Dengjiashan type deposits.
