Through the field investigation and laboratory analysis,this paper describes the regular pattern of community succession on the deserted land of Shizishan copper tailings in Tongling City.There are 49 species of natur...Through the field investigation and laboratory analysis,this paper describes the regular pattern of community succession on the deserted land of Shizishan copper tailings in Tongling City.There are 49 species of natural colonized plants on the wasteland,which are subordinate to 15 families and 38 genera.The main families are Compositae(12 species),Gramineae(11 species),Leguminosae(8 species)and Hippochaete ramosissimum,which belong to Equisetaceae.The extreme soil infertility and excessively concentration of heavy metals(especially Cu and Cd)are the main limiting factors to plants colonization.The vegetation on the deserted land of copper tailings is distributed in spot piece and scattered mainly with fewer species of plant,with lower species diversity.Annual and biennial herbs and grasses are dominant components.Cynodon dactylon,Imperata cylindrica var.major,Lespedeza chinensis,Erigeron annuus and H.ramosissimum etc.have a higher summed dominance ratio.The natural formation of plant community on the deserted land of copper tailings usually goes through seeds spread,invasion,ecesis,aggregation and species competition.After several years of primary natural restoration,14 communities were formed.According to their community composition and structure level,the 14 communities are divided into three primary succession stages,namely monodominant,subdominant and codominant species communities.With the formation and succession of these communities,species were enriched and diversity increased,the margin of summed dominance ratio of species in each community decreased,and the composition or structure of community became complex.展开更多
To improve the success rate of locating hydrocarbon reservoirs in pre-Cenozoic inland compressional basins, taking the Early Yanshanian succession of eastern Yihezhuang salient as an example, this paper studied the se...To improve the success rate of locating hydrocarbon reservoirs in pre-Cenozoic inland compressional basins, taking the Early Yanshanian succession of eastern Yihezhuang salient as an example, this paper studied the sedimentary facies and sequence stratigraphic patterns. First, through seismic profiles, well logs, cores and outcrops, the sequence framework was established and internal sedimentary facies were identified. Further, according to analysis of single-wells and connecting-wells, the vertical evolution and horizontal distribution of sedimentation inside the sequence frameworks were discussed. The following results were acquired:(1) meandering river characterized by dual structures superposing each other was developed, and the dual structures can be further divided into three kinds;(2) the entire Early Yanshanian succession was interpreted as one first-order sequence, composed of three third-order sequences, including SQ-Fz1, SQ-Fz2 and SQ-St from bottom to top. Each third-order sequence can be further divided into three system tracts;(3) in different system tracts, different types of dual structures developed separately, and sedimentary bodies showed different horizontal distribution scales and vertical superposition patterns. Finally, the model of sequence stratigraphic patterns was established. This study enhanced the use of sequence stratigraphy to inland tectonically active basins, and would be helpful to predict reservoirs in pre-Cenozoic residual basins.展开更多
Analyzing and understanding the structure and growth dynamics of forests at different stages is helpful to promote forest succession, restoration and management. Three spots representing three succession stages of spr...Analyzing and understanding the structure and growth dynamics of forests at different stages is helpful to promote forest succession, restoration and management. Three spots representing three succession stages of spruce-fir mixed forest(SF: polar-birch secondary forest, MF: spruce-fir mixed forest and PF: spruce-fir near primary forest) were established. Structure, growth dynamics during two growth seasons for dominant tree species, regeneration were examined, and a univariate O-ring function statistic was used to analyze the spatial patterns of main regeneration tree species. Results showed that,(1) composition of tree species, periodic annual increment(PAI) of the diameter at breast height(DBH), basal area for overstory trees and of ground diameter(DGH) for saplings, were significantly different with the succession;(2) the current species composition and regeneration dynamics of SF suggested a development towards spruce-fir mixed forests. Pioneer species like Betula platyphyllaa will gradually disappear while climax species, such as Abies nephrolepis, Pinus koraiensis, Picea koraiensis and Tilia amurensis will dominate forest stands;(3) Despite the highest volume occurring in PF, and saplings in it grew better than in the others, this forest type is unstable because of its unsustainable structure of DBH class and insufficient regeneration; and(4) MF had the most reasonable distribution of DBH class for adult trees(DBH > 5.0 cm) and DGH class for saplings(H ≥30 cm and DBH ≤5 cm), as well as an optimal volume increment. Limiting canopy opening size can lessen the physiological stress and promote the growth and competitive status of regeneration. Management implications for increasing the gaps and thus creating better growth conditions for understory saplings and facilitating forest succession were discussed.展开更多
A method is presented for incrementally computing success patterns of logic programs. The set of success patterns of a logic program with respect to an abstraction is formulated as the success set of an equational log...A method is presented for incrementally computing success patterns of logic programs. The set of success patterns of a logic program with respect to an abstraction is formulated as the success set of an equational logic program modulo an equality theory that is induced by the abstraction. The method is exemplified via depth and stump abstractions. Also presented are algorithms for computing most general unifiers modulo equality theories induced by depth and stump abstractions.展开更多
Top executive succession is one of the most crucial events in the life of any firm. Based on the database of Chinese Entrepreneur Survey System, this research firstly reports new factors that influence the likelihood ...Top executive succession is one of the most crucial events in the life of any firm. Based on the database of Chinese Entrepreneur Survey System, this research firstly reports new factors that influence the likelihood of succession in Chinese corporations, which may not exist in western companies, then tests previous western research result in Chinese information technology （IT） industry and traditional industry. The results are hopefully to enlighten the reform of corporations during the period of China transitional economy.展开更多
The case study based on Qinling Mountains in Shaanxi Province of China, in virtue of the information from TM image, classifies the land types and analyzes their spatial and temporal differential law, and puts forward ...The case study based on Qinling Mountains in Shaanxi Province of China, in virtue of the information from TM image, classifies the land types and analyzes their spatial and temporal differential law, and puts forward three structural patterns of land types in mountainous areas, namely, spatial, quantitative and qualitative structures of mountainous land types. Furthermore, it has been noticed that the analysis of structural patterns can disclose the heterogeneity and orderliness of combination of land types, which can lay the theoretic foundation for comprehensively recognizing ecological characteristics and succession law of structure and function of land types. After the all-around comparative analysis, an optimal allocation of land use in Qinling Mountains has been put forward according to the principle of sustainable development and landscape ecology, which can lay the scientific foundation in practice for the structural adjustment and distribution optimization from the macro level to micro level.展开更多
The succession of benthic fauna characterizes the environmental dynamics of cold seep ecosystems,offering insights into deepsea biodiversity patterns and the influence of geofluid on the local biosphere.Previous studi...The succession of benthic fauna characterizes the environmental dynamics of cold seep ecosystems,offering insights into deepsea biodiversity patterns and the influence of geofluid on the local biosphere.Previous studies documented the presence and abundance of specific taxa at different stages of seep development,revealing the patchy distribution of faunal assemblages[1].As research progresses,specific environmental factors,including the levels of methane,sulfide.展开更多
文摘Through the field investigation and laboratory analysis,this paper describes the regular pattern of community succession on the deserted land of Shizishan copper tailings in Tongling City.There are 49 species of natural colonized plants on the wasteland,which are subordinate to 15 families and 38 genera.The main families are Compositae(12 species),Gramineae(11 species),Leguminosae(8 species)and Hippochaete ramosissimum,which belong to Equisetaceae.The extreme soil infertility and excessively concentration of heavy metals(especially Cu and Cd)are the main limiting factors to plants colonization.The vegetation on the deserted land of copper tailings is distributed in spot piece and scattered mainly with fewer species of plant,with lower species diversity.Annual and biennial herbs and grasses are dominant components.Cynodon dactylon,Imperata cylindrica var.major,Lespedeza chinensis,Erigeron annuus and H.ramosissimum etc.have a higher summed dominance ratio.The natural formation of plant community on the deserted land of copper tailings usually goes through seeds spread,invasion,ecesis,aggregation and species competition.After several years of primary natural restoration,14 communities were formed.According to their community composition and structure level,the 14 communities are divided into three primary succession stages,namely monodominant,subdominant and codominant species communities.With the formation and succession of these communities,species were enriched and diversity increased,the margin of summed dominance ratio of species in each community decreased,and the composition or structure of community became complex.
基金supported by the National Natural Science Foundation of China (NSFC) (No. 41472216)the Natural Science Foundation of Shandong Province (No. ZR2016DB29)+3 种基金the Project supported by Shandong Provincial Key Laboratory of Depositional Mineralization & Sedimentary Mineral, Shandong University of Science and Technology (No. DMSM2017015)the Water Conservancy Scientific Research and Technology Promotion Projects of Shandong Province (No. SDSLKY201808)the Natural Science Foundation of Jinan University (No. XBS1647)Petroleum Development Centre of the Shengli Oilfield Company for their support
文摘To improve the success rate of locating hydrocarbon reservoirs in pre-Cenozoic inland compressional basins, taking the Early Yanshanian succession of eastern Yihezhuang salient as an example, this paper studied the sedimentary facies and sequence stratigraphic patterns. First, through seismic profiles, well logs, cores and outcrops, the sequence framework was established and internal sedimentary facies were identified. Further, according to analysis of single-wells and connecting-wells, the vertical evolution and horizontal distribution of sedimentation inside the sequence frameworks were discussed. The following results were acquired:(1) meandering river characterized by dual structures superposing each other was developed, and the dual structures can be further divided into three kinds;(2) the entire Early Yanshanian succession was interpreted as one first-order sequence, composed of three third-order sequences, including SQ-Fz1, SQ-Fz2 and SQ-St from bottom to top. Each third-order sequence can be further divided into three system tracts;(3) in different system tracts, different types of dual structures developed separately, and sedimentary bodies showed different horizontal distribution scales and vertical superposition patterns. Finally, the model of sequence stratigraphic patterns was established. This study enhanced the use of sequence stratigraphy to inland tectonically active basins, and would be helpful to predict reservoirs in pre-Cenozoic residual basins.
基金co-supported by the "948" Project of the State Forestry Administration of China (Grant No. 2013-4-66)"The Twelfth Five-Year-Plan" of National Science and Technology for Rural Development in China (Grant No. 2012BAD22B0203)
文摘Analyzing and understanding the structure and growth dynamics of forests at different stages is helpful to promote forest succession, restoration and management. Three spots representing three succession stages of spruce-fir mixed forest(SF: polar-birch secondary forest, MF: spruce-fir mixed forest and PF: spruce-fir near primary forest) were established. Structure, growth dynamics during two growth seasons for dominant tree species, regeneration were examined, and a univariate O-ring function statistic was used to analyze the spatial patterns of main regeneration tree species. Results showed that,(1) composition of tree species, periodic annual increment(PAI) of the diameter at breast height(DBH), basal area for overstory trees and of ground diameter(DGH) for saplings, were significantly different with the succession;(2) the current species composition and regeneration dynamics of SF suggested a development towards spruce-fir mixed forests. Pioneer species like Betula platyphyllaa will gradually disappear while climax species, such as Abies nephrolepis, Pinus koraiensis, Picea koraiensis and Tilia amurensis will dominate forest stands;(3) Despite the highest volume occurring in PF, and saplings in it grew better than in the others, this forest type is unstable because of its unsustainable structure of DBH class and insufficient regeneration; and(4) MF had the most reasonable distribution of DBH class for adult trees(DBH > 5.0 cm) and DGH class for saplings(H ≥30 cm and DBH ≤5 cm), as well as an optimal volume increment. Limiting canopy opening size can lessen the physiological stress and promote the growth and competitive status of regeneration. Management implications for increasing the gaps and thus creating better growth conditions for understory saplings and facilitating forest succession were discussed.
文摘A method is presented for incrementally computing success patterns of logic programs. The set of success patterns of a logic program with respect to an abstraction is formulated as the success set of an equational logic program modulo an equality theory that is induced by the abstraction. The method is exemplified via depth and stump abstractions. Also presented are algorithms for computing most general unifiers modulo equality theories induced by depth and stump abstractions.
文摘Top executive succession is one of the most crucial events in the life of any firm. Based on the database of Chinese Entrepreneur Survey System, this research firstly reports new factors that influence the likelihood of succession in Chinese corporations, which may not exist in western companies, then tests previous western research result in Chinese information technology （IT） industry and traditional industry. The results are hopefully to enlighten the reform of corporations during the period of China transitional economy.
基金Key project on Knowledge Innovation of Chinese Academy of Sciences, KZCX2-310-05
文摘The case study based on Qinling Mountains in Shaanxi Province of China, in virtue of the information from TM image, classifies the land types and analyzes their spatial and temporal differential law, and puts forward three structural patterns of land types in mountainous areas, namely, spatial, quantitative and qualitative structures of mountainous land types. Furthermore, it has been noticed that the analysis of structural patterns can disclose the heterogeneity and orderliness of combination of land types, which can lay the theoretic foundation for comprehensively recognizing ecological characteristics and succession law of structure and function of land types. After the all-around comparative analysis, an optimal allocation of land use in Qinling Mountains has been put forward according to the principle of sustainable development and landscape ecology, which can lay the scientific foundation in practice for the structural adjustment and distribution optimization from the macro level to micro level.
基金supported by the National Natural Science Founda-tion of China(42122045 and 42306171)the Development Fund of South China Sea Institute of Oceanology,Chinese Academy of Sciences(SCSIO202202)the PI project of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(GML20190609).
文摘The succession of benthic fauna characterizes the environmental dynamics of cold seep ecosystems,offering insights into deepsea biodiversity patterns and the influence of geofluid on the local biosphere.Previous studies documented the presence and abundance of specific taxa at different stages of seep development,revealing the patchy distribution of faunal assemblages[1].As research progresses,specific environmental factors,including the levels of methane,sulfide.
