We introduce the concept of γ-(α, β)-open sets and the concepts of γ-(α, β)-T_i spaces(i = 0, 1, 2, 3, 4) based on the concept of(α, β)-open sets. We obtain some properties of γ-(α, β)-Tispaces. Furthermore...We introduce the concept of γ-(α, β)-open sets and the concepts of γ-(α, β)-T_i spaces(i = 0, 1, 2, 3, 4) based on the concept of(α, β)-open sets. We obtain some properties of γ-(α, β)-Tispaces. Furthermore, we study their essential characterization in topological space.展开更多
The distribution of Oil & gas fields shows their close relationship with the most active tectonic regions. This is not a coincidence but having a scientific reasons. The crustal active regions, refer to the places...The distribution of Oil & gas fields shows their close relationship with the most active tectonic regions. This is not a coincidence but having a scientific reasons. The crustal active regions, refer to the places where the active natural earthquake, volcanic activities, underground water happened, and the areas of the leaking Off of natural gas to the surface of the crust. The magma of volcanic activities brings the organic "kitchen range body" hydrocarbon - generating model and inorganic genetic hydrocarbon to the regions covered by volcanic rock. Underground water brings a catalytic hydrocarbon generating model for organic matter, and the leaking - off of H2 and CO2 contributes a synthetic hydrocarbon - generating model. Volcanic activities bring the assemblage of Source, Reservoir and Seal formed by the sediments and magma the sedimentary basins, and the hydrocarbon - generating system with a "water - volcano" binary structure is formed. All these conditions are favorable and excellent for the formation of oil & gas fields. The distribution of AInerican oil & gas fields have very close relationship with the mines of Fe, Mn, Cr, Mo, W and V, deposits of Zn, Cu, V, Pb, Al and Hg, and the deposits of fluorite, sulfur, potassium salt, phosphate and halite, and the distribution of sulfate - chloride of river water. The reason why few oil & gas fields discovered in the regions covered by volcanic rock in western America maybe because of the view of "inconsistency between petroleum and volcano". Further more, It’s very difficult to carry out a geophysical exploration in such kinds of regions. This paper examined a few hydrocarbon - generating models (systems) mentioned above and came up with some flesh ideas on the exploration in the areas covered with volcanic rocks.展开更多
The U.S. Senate unanimously confirmed, by a.92 to 0 vote, Representative Dick Cheney as defence secretary on March 17. On March 18, the US space shuttle "Discovery" landed in California, completing a flight ...The U.S. Senate unanimously confirmed, by a.92 to 0 vote, Representative Dick Cheney as defence secretary on March 17. On March 18, the US space shuttle "Discovery" landed in California, completing a flight of nearly five days that covered about three million kilometres. The Second Session of the Seventh National People’s Congress opened on March 20 in Beijing. Chinese Premier Li展开更多
We present CCD photometric observations of an eclipsing binary in the direction of the open cluster Praesepe using the 2 m telescope at IUCAA Girawali Observatory, India. Though the system was classified as an eclipsi...We present CCD photometric observations of an eclipsing binary in the direction of the open cluster Praesepe using the 2 m telescope at IUCAA Girawali Observatory, India. Though the system was classified as an eclipsing binary by Pepper et al., detailed investigations have been lacking. The photometric solutions using the Wilson-Devinney code suggest that it is a W-type W UMa system and, interestingly, the system parameters are similar to another contact binary system SW Lac.展开更多
In this paper, we study the concept of soft sets which is introduced by Molodtsov [5]. We give the definition of (τ1,τ2)-semi open soft (resp. (τ1,τ2)-pre open soft, (τ1,τ2)-α-open soft, (τ1,τ2)-β-open soft...In this paper, we study the concept of soft sets which is introduced by Molodtsov [5]. We give the definition of (τ1,τ2)-semi open soft (resp. (τ1,τ2)-pre open soft, (τ1,τ2)-α-open soft, (τ1,τ2)-β-open soft, (τ1,τ2)'-semi open soft, (τ1,τ2)'-pre open soft, (τ1,τ2)'-α-open soft, (τ1,τ2)'-βopen soft) set via two soft topologies. Also we introduce (τ1,τ2)-regular open soft and ESDC on two soft topologies. The aim of this paper is to investigate properties of some mixed soft operations and characterizations of ESDC. Finally, we study τ2-ESDC soft topologies τ1.展开更多
It is necessary to reconstruct past changes in land use and land cover to under- stand the historical effects of humans on climate and the local environment. We collected information from historical documents on the c...It is necessary to reconstruct past changes in land use and land cover to under- stand the historical effects of humans on climate and the local environment. We collected information from historical documents on the cropland area at the county level for Heilongji- ang Province, northeast China during 1900-1910. The original records from different histori- cal documents were calibrated with each other. We then defined an agricultural suitability index quantified by the distance from settlements, the slope and complexity of the topography, and the distance from rivers. Following the order of the agricultural suitability index from high to low values, the documented areas of cropland at the county level were then allocated into 1 km x 1 km cells. The area of cropland in 2009 was then retrieved from Landsat ETM＋ images and compared with the areas of cropland during 1900-1910 to determine the human-induced changes in land use and land cover. In this period, the total area of cropland was about 25,397 km2 and this mainly occurred in the mid-southern part of Heilongjiang, in particular the six counties of Hailun, Bayan, Wuchang, Hulan, Shuangcheng and Wangkui. In 2009, the total area of cropland had increased to about 163,808 km2 and had spread over the south- western part to the central and northeastern parts of Heilongjiang. The area of cropland had therefore increased by about 138,411 km2 during the 20th century. The proportion of land used as cropland increased from about 5.6% during 1900-1910 to about 36.2% in 2009, indicating that about 30.6% of the natural land surface in Heilongjiang was replaced by cropland. A total of about 44% （60,962 km2） of the cropland was converted from forest, mainly on the western edge and in the northeastern part of the present-day agricultural area. These areas of cropland reconstructed from historical records for the period 1900-1910 could be used as a basic data set to study the effects of agricultural development on climate and the local environment.展开更多
文摘We introduce the concept of γ-(α, β)-open sets and the concepts of γ-(α, β)-T_i spaces(i = 0, 1, 2, 3, 4) based on the concept of(α, β)-open sets. We obtain some properties of γ-(α, β)-Tispaces. Furthermore, we study their essential characterization in topological space.
文摘The distribution of Oil & gas fields shows their close relationship with the most active tectonic regions. This is not a coincidence but having a scientific reasons. The crustal active regions, refer to the places where the active natural earthquake, volcanic activities, underground water happened, and the areas of the leaking Off of natural gas to the surface of the crust. The magma of volcanic activities brings the organic "kitchen range body" hydrocarbon - generating model and inorganic genetic hydrocarbon to the regions covered by volcanic rock. Underground water brings a catalytic hydrocarbon generating model for organic matter, and the leaking - off of H2 and CO2 contributes a synthetic hydrocarbon - generating model. Volcanic activities bring the assemblage of Source, Reservoir and Seal formed by the sediments and magma the sedimentary basins, and the hydrocarbon - generating system with a "water - volcano" binary structure is formed. All these conditions are favorable and excellent for the formation of oil & gas fields. The distribution of AInerican oil & gas fields have very close relationship with the mines of Fe, Mn, Cr, Mo, W and V, deposits of Zn, Cu, V, Pb, Al and Hg, and the deposits of fluorite, sulfur, potassium salt, phosphate and halite, and the distribution of sulfate - chloride of river water. The reason why few oil & gas fields discovered in the regions covered by volcanic rock in western America maybe because of the view of "inconsistency between petroleum and volcano". Further more, It’s very difficult to carry out a geophysical exploration in such kinds of regions. This paper examined a few hydrocarbon - generating models (systems) mentioned above and came up with some flesh ideas on the exploration in the areas covered with volcanic rocks.
文摘The U.S. Senate unanimously confirmed, by a.92 to 0 vote, Representative Dick Cheney as defence secretary on March 17. On March 18, the US space shuttle "Discovery" landed in California, completing a flight of nearly five days that covered about three million kilometres. The Second Session of the Seventh National People’s Congress opened on March 20 in Beijing. Chinese Premier Li
文摘We present CCD photometric observations of an eclipsing binary in the direction of the open cluster Praesepe using the 2 m telescope at IUCAA Girawali Observatory, India. Though the system was classified as an eclipsing binary by Pepper et al., detailed investigations have been lacking. The photometric solutions using the Wilson-Devinney code suggest that it is a W-type W UMa system and, interestingly, the system parameters are similar to another contact binary system SW Lac.
文摘In this paper, we study the concept of soft sets which is introduced by Molodtsov [5]. We give the definition of (τ1,τ2)-semi open soft (resp. (τ1,τ2)-pre open soft, (τ1,τ2)-α-open soft, (τ1,τ2)-β-open soft, (τ1,τ2)'-semi open soft, (τ1,τ2)'-pre open soft, (τ1,τ2)'-α-open soft, (τ1,τ2)'-βopen soft) set via two soft topologies. Also we introduce (τ1,τ2)-regular open soft and ESDC on two soft topologies. The aim of this paper is to investigate properties of some mixed soft operations and characterizations of ESDC. Finally, we study τ2-ESDC soft topologies τ1.
基金National Natural Science Foundation of China, No.42171217 No.41471171
文摘It is necessary to reconstruct past changes in land use and land cover to under- stand the historical effects of humans on climate and the local environment. We collected information from historical documents on the cropland area at the county level for Heilongji- ang Province, northeast China during 1900-1910. The original records from different histori- cal documents were calibrated with each other. We then defined an agricultural suitability index quantified by the distance from settlements, the slope and complexity of the topography, and the distance from rivers. Following the order of the agricultural suitability index from high to low values, the documented areas of cropland at the county level were then allocated into 1 km x 1 km cells. The area of cropland in 2009 was then retrieved from Landsat ETM＋ images and compared with the areas of cropland during 1900-1910 to determine the human-induced changes in land use and land cover. In this period, the total area of cropland was about 25,397 km2 and this mainly occurred in the mid-southern part of Heilongjiang, in particular the six counties of Hailun, Bayan, Wuchang, Hulan, Shuangcheng and Wangkui. In 2009, the total area of cropland had increased to about 163,808 km2 and had spread over the south- western part to the central and northeastern parts of Heilongjiang. The area of cropland had therefore increased by about 138,411 km2 during the 20th century. The proportion of land used as cropland increased from about 5.6% during 1900-1910 to about 36.2% in 2009, indicating that about 30.6% of the natural land surface in Heilongjiang was replaced by cropland. A total of about 44% （60,962 km2） of the cropland was converted from forest, mainly on the western edge and in the northeastern part of the present-day agricultural area. These areas of cropland reconstructed from historical records for the period 1900-1910 could be used as a basic data set to study the effects of agricultural development on climate and the local environment.
