Da Sheng Bian,a significant work on obstetrics and gynecology that emerged in the early Qing Dynasty,was initially published as“A Treatise on Midwifery”in 1842 by William Lockhart,a British missionary to China.In 18...Da Sheng Bian,a significant work on obstetrics and gynecology that emerged in the early Qing Dynasty,was initially published as“A Treatise on Midwifery”in 1842 by William Lockhart,a British missionary to China.In 1894,John G.Kerr,an American missionary,translated the text as“The Tat Shang Pin”.This paper conducts a comparative study of the two English translations using a self-constructed English-Chinese parallel corpus of Da Sheng Bian.The study explores the translation styles of the two translators by examining the token-types ratio and frequency at the lexical level,mean sentence length at the syntactic level,and the use of conjunctions at the discourse level.The observed differences in translation styles between the two translations are analyzed in relation to the translators’backgrounds and translation strategies.展开更多
A dandelion algorithm(DA) is a recently developed intelligent optimization algorithm for function optimization problems. Many of its parameters need to be set by experience in DA,which might not be appropriate for all...A dandelion algorithm(DA) is a recently developed intelligent optimization algorithm for function optimization problems. Many of its parameters need to be set by experience in DA,which might not be appropriate for all optimization problems. A self-adapting and efficient dandelion algorithm is proposed in this work to lower the number of DA's parameters and simplify DA's structure. Only the normal sowing operator is retained;while the other operators are discarded. An adaptive seeding radius strategy is designed for the core dandelion. The results show that the proposed algorithm achieves better performance on the standard test functions with less time consumption than its competitive peers. In addition, the proposed algorithm is applied to feature selection for credit card fraud detection(CCFD), and the results indicate that it can obtain higher classification and detection performance than the-state-of-the-art methods.展开更多
本文探讨模糊法则的翻译应用价值,旨在为模糊语言的分析提供一个可以参考的模板。文章首先从模糊语言学(包括模糊语义学和模糊语用学)、模糊美学、模糊逻辑学、模糊数学、模糊修辞学五个维度,对"模糊"概念的界定进行回顾和分...本文探讨模糊法则的翻译应用价值,旨在为模糊语言的分析提供一个可以参考的模板。文章首先从模糊语言学(包括模糊语义学和模糊语用学)、模糊美学、模糊逻辑学、模糊数学、模糊修辞学五个维度,对"模糊"概念的界定进行回顾和分析,并提出翻译学中最宜采取的解释。然后,文章以The Da Vinci Code为个案,从语言时空、文化时空、修辞时空层面切入,探索文本中模糊语言所表现出的形式特点以及翻译处理所采取的对策。展开更多
Mesozoic bimodal volcanic rocks of basaltic andesite and rhyolite are widely distributed in the Da Hinggan Range, but their petrogenetic relationships and geodynamic implications are rarely constrained. Detailed studi...Mesozoic bimodal volcanic rocks of basaltic andesite and rhyolite are widely distributed in the Da Hinggan Range, but their petrogenetic relationships and geodynamic implications are rarely constrained. Detailed studies on doleritic and porphyry dikes in the Zhalantun area indicate that they display features of magma mixing, suggesting their coeval formation. In situ zircon U-Pb dating shows that the porphyry was emplaced in the Early Cretaceous with a ^206Pb/^238U age of 130±1 Ma. Zircons from the dolerite also yield an Early Cretaceous emplacement age of 124±2 Ma although some inherited zircons have been identified. These age results indicate that the Early Cretaceous was an important period of magmatism in the Da Hinggan Range. Zircons from porphyry are characterized by positive value of εHf（t） as high as 10.3±0.5 with Hf depleted mantle model age of 349-568 Ma, whereas magmatic zircons from the dolerite have εHf（t） value of 11.0±1.4 with Hf depleted mantel model age of 342-657 Ma, consistent with those from the porphyry. Considering other data on the geological evolution of this area, it is concluded that the mafic magma originated from the partial melting of Paleozoic enriched lithospheric mantle, whereas the felsic magma came from recycling of juvenile crust formed during the Paleozoic. Both of the protoliths are closely related to the subduction of the Paleo-Asian Ocean during the Paleozoic, indicating that the Paleozoic is an important period of large-scale crustal growth in the area.展开更多
High-resolution tomographic images of the belt crossing the Japan Trench-Changbai Mountains-Dong Ujimqin Qi are represented in this paper, revealing the shape of a subducted slab in the western Pacific region and char...High-resolution tomographic images of the belt crossing the Japan Trench-Changbai Mountains-Dong Ujimqin Qi are represented in this paper, revealing the shape of a subducted slab in the western Pacific region and characteristics of the lithospheric structures under the Changbai Mountains and the Da Hinggan Mountains. Studies of the spatial distribution, subduction time and the time-lag between the subduction and magmatism, combined with petrology and isotope geochemistry of the Late Mesozoic volcano-plutonic rocks from the Da Hinggan Mountains-Yanshan Mountains have further proved the independence of magmatic activities from the subduction of the Pacific plate. The Mesozoic tectono-thermal evolutionary history and structural characteristics of the lithosphere in the Da Hinggan Mountains and North China suggest that the formation and evolution of magma have probably a close relationship with the delamination and thinning of the continental lithosphere and the underplating resulting from the consequent upwelling of the asthenosphere. On the other hand, the large-scale strike-slip fault system, resulting from sinistral shearing of the Pacific plate relative to the Asian continent in the Mesozoic, is responsible for the formation and emplacement of magma on the continental margin. It was the intense crust-mantle interaction, together with structural deformation at the shallower levels that led to the large tectono-magmatic belt in the East Asian continental margin.展开更多
The question whether there have been Quaternary glaciations in the Da Hinggan area has puzzled glacial geologists for many years because no sufficient glacial evidence has been found in this area. The study of Quatern...The question whether there have been Quaternary glaciations in the Da Hinggan area has puzzled glacial geologists for many years because no sufficient glacial evidence has been found in this area. The study of Quaternary glaciers in the Da Hinggan area is also a key issue of the glaciology in China because of the special location of this area. In the past two years, a large number of complete and typical glacial vestiges have been found in Hexigten in the southern Da Hinggan Mountains, such as fossil cirque groups, horns, knife-edge crests, terminal moraines, glacial stepped stones. These landforms are located at a watershed, which are thus impossible to be formed due to tectonic processes, water or weathering, but can only be formed by glaciation. The calculated flat indexes of the fossil cirques in the Hexigten are 1.7-4.5, 4-5 and 1.3-5, which are within the range of 1.7-5 that is the flat index of real cirques. The typical and complete moraines have also been found in this area. All these glacial vestiges prove that the Quaternary glaciers did exist in the Da Hinggan Mountains of eastern China. Thus, it is of important scientific significance for the research on Chinese, even the global climatic and environmental evolution since the Quaternary.展开更多
The Bianbianshan deposit, the unique gold-polymetal （Au-Ag-Cu-Pb-Zn） veined deposit of the polymetal metallogenic belt of the southern segment of Da Hinggan Mountains mineral province, is located at the southern par...The Bianbianshan deposit, the unique gold-polymetal （Au-Ag-Cu-Pb-Zn） veined deposit of the polymetal metallogenic belt of the southern segment of Da Hinggan Mountains mineral province, is located at the southern part of the Hercynian fold belt of the south segment of Da Hinggan Mountains mineral province, NE China. Ores at the Bianbianshan deposit occur within Cretaceous andesite and rhyolite in the form of gold-bearing quartz veins and veinlet groups containing native gold, electrum, pyrite, chalcopyrite, galena and sphalerite. The deposit is hosted by structurally controlled faults associated with intense hydrothermal alteration. The typical alteration assemblage is sericite ＋ chlorite ＋ calcite ＋ quartz, with an inner pyrite-sericite-quartz zone and an outer seicite - chlorite - calcite-epidote zone between orebodies and wall rocks. δ34 S values of 17 sulfides from ores changing from -1.67 to ＋0.49‰ with average of -0.49‰, are similar to δ34 S values of magmatic or igneous sulfide sulfur. 206Pb/204Pb, 207Pb/204Pb and 208Pb/ 204Pb data of sulfide from ores range within 17.66-17.75, 15.50-15.60, and 37.64-38.00, respectively. These sulfur and lead isotope compositions imply that ore-forming materials might mainly originate from deep sources. H and O isotope study of quartz from ore-bearing veins indicate a mixed source of deep-seated magmatic water and shallower meteoric water. The ore formations resulted from a combination of hydrothermal fluid mixing and a structural setting favoring gold-polymetal deposition. Fluid mixing was possibly the key factor resulting in Au-Ag-Cu-Pb-Zn deposition in the deposit. The metallogenesis of the Bianbianshan deposit may have a relationship with the Cretaceous volcanic-subvolcanic magmatic activity, and formed during the late stage of the crust thinning of North China.展开更多
Eclogite was firstly discovered at the Da Qaidam region (Yang,et al., 1998), and then in the Xitieshan and Dulan regions in 1999, constituting an over 350km long high\|pressure metamorphic belt in the northeastern Qin...Eclogite was firstly discovered at the Da Qaidam region (Yang,et al., 1998), and then in the Xitieshan and Dulan regions in 1999, constituting an over 350km long high\|pressure metamorphic belt in the northeastern Qinghai—Tibet plateau. Eclogites occur as pods in the garnet\|muscovite gneiss of the Dakendaban Group (or called Shaliuhe Group in Dulan) of Upper Proterozoic age. In general, the pods of eclogite vary in size; most of them are less than 20m×10m, some large ones up to about 100m×50m. The eclogite\|hosted gneiss is pale\|gray in color, consisting mainly plagioclase and quartz, and minor muscovite (5%～10% in vol.) and garnet (1%～2%). Some of the country rocks of eclogite are mica\|quartz\|(feldspar) schist, quartzite, and ultramafic rocks, the latter also occur in blocks.Over 50 pods were found in a belt of 10km×3km in the Da Qaidam region (No.1 location). Only a few pods of eclogite were found in the Xitieshan region in 1999 field expedition (No.2 location). Eclogite in Dulan occurs in the Proterozoic strata of Shaliuhe Group (same as the Dakendaban Group but with a different name). The eclogites in the Dulan region (No.3 location) expose about 10km wide in SN and an unknown length in EW, and can be subdivided into two belts, the North Eclogite Belt of Dulan (NEBD) and the South Eclogite Belt of Dulan (SEBD).展开更多
Mantle branch structure is the third tectonic unit of multiple evolution of a mantle branch. It is not only the main mechanism of intercontinental orogeny, but also an important ore-forming and ore-control structure. ...Mantle branch structure is the third tectonic unit of multiple evolution of a mantle branch. It is not only the main mechanism of intercontinental orogeny, but also an important ore-forming and ore-control structure. Studies on geotectonic evolution, regional geological characteristics and oreforming and ore-control structures have shown that since the Mesozoic the Da Hinggan Mts. region has entered a typical intercontinental orogenic stage, and it is closely related to mantle branch activities. The south-central segment of the Da Hinggan Mts. is a typical mantle branch structure and possesses obvious magmatic-metamorphic complexes in the core, detachment slip beds in the periphery and overlapped fault depression basins. Moreover, all of these are the principal factors leading to ore formation and ore control in the region. This paper also further explores the mechanism of mineralization in the south-central segment of the Da Hinggan, summaries the rules of mineralization, puts forward the models of mineralization and points out future ore-exploring orientation.展开更多
Following the trends of Chinese rural transformation development, and the sustainable development goals for resources and environment, reasonable arranging the potential development space and the ecological space, so ...Following the trends of Chinese rural transformation development, and the sustainable development goals for resources and environment, reasonable arranging the potential development space and the ecological space, so as to optimize the distributions of rural settlement would be the key challenge for rural areas in ecologically fragile regions. From the perspective of maintaining regional ecological security, this paper takes Da’an City, a typical ecological fragile region in Jilin Province, as the case area, constructing the comprehensive ecological security pattern(ESP) on basis of landscape ecology, and applying the landscape pattern indexes to quantitative analysis the spatial distribution characteristics of rural settlements. Then, different optimization directions and management strategies are put forward for rural settlements in each secure zone under the comprehensive ESP. The experimental results showed that 1) the area of the low security zone, the general security zone, the moderate security zone and the extreme security zone was 1570.18 km^2, 1463.36 km^2, 1215.80 km^2 and 629.77 km^2, representing 32.18%, 29.99%, 24.92% and 12.91% of the total area of the target area, respectively. 2) The rural settlements in Da’an City were characterized by a high degree of fragmentation with a large number of small-scale patches. 3) The area of rural settlements in the ecological relocation zone, the in situ remediation zone, the limited development zone and the key development zone was 22.80 km^2, 42.31 km^2, 36.28 km^2 and 19.40 km^2, accounting for 18.88%, 35.03%, 30.04% and 16.06% of the total area of rural settlements, respectively. Then, different measures were proposed for settlements in different optimization zones in order to scientifically plan important ecological space, production space and living space in rural areas. This paper aims to provide fundamental support for rural settlements based on redistribution from the perspective of landscape ecology and provide insights for rural planning and rural habitat environmental improvement.展开更多
Physicochemical parameters of mineralization such as temperature, pressure, salinity, density, composition and boiling of ore fluids as well as pH, Eh, fo2 and reducing parameter in theprocess of mineralization of maj...Physicochemical parameters of mineralization such as temperature, pressure, salinity, density, composition and boiling of ore fluids as well as pH, Eh, fo2 and reducing parameter in theprocess of mineralization of major ore deposits in the study district have been obtained by the authors through systematic observation and determination of characteristics and phase changes of fluid inclusions at different temperatures and analysis of gaseous and liquid phase compositions of the inclusions, thus providing a scientific basis for the division of mineralization-alteration stages, types of mineral deposits and minerogenetic series and the deepening of the knowledge about the ore-forming processes and mechanisms of mineral deposits. It is indicated that the deposits of the same type have similar fluid inclusion geochemical features and physicochemical parameters though they belong to different minerogenetic series, while the compositions of inclusions are not conditioned by deposit types but closely related to the minerogenetic series of deposits.展开更多
Whole-rock geochemical, zircon U-Pb geochronological and Sr-Nd-Hf isotopic data are presented for the Early Cretaceous volcanic rocks from the northern Da Hinggan Mountains. The volcanic rocks generally display high S...Whole-rock geochemical, zircon U-Pb geochronological and Sr-Nd-Hf isotopic data are presented for the Early Cretaceous volcanic rocks from the northern Da Hinggan Mountains. The volcanic rocks generally display high SiO2 （73.19-77.68 wt%） and Na20＋K20 （6.53-8.98 wt%） contents, with enrichment in Rb, Th, U, Pb and LREE, and depletion in Nb, Ta, P and Ti. Three rhyolite samples, one rhyolite porphyry sample, and one volcanic breccia sample yield weighted mean 206pb/23SU ages of 135.1±1.2 Ma, 116.5±1.1 Ma, 121.9±1.0 Ma, 118.1±0.9 Ma and 116.9±1.4 Ma, respectively. All these rocks have moderate （STSr/S6Sr）i values of 0.704912 to 0.705896, slightly negative eNd（t） values of -1.4 to -0.1, and positive Cur（t） values of 3.7 to 8. Their zircon Hf and whole-rock Nd isotopic model ages range from 594 to 1024 Ma. These results suggest that the Early Cretaceous volcanic rocks were originated from melting of subducted oceanic crust and associated sediments during the closure of the Mongol-Okhotsk Ocean.展开更多
基金Phased research results of“The Research and Practice of International Communication Ability Training of English Students”(Approval No.HNJG-2022-0678)。
文摘Da Sheng Bian,a significant work on obstetrics and gynecology that emerged in the early Qing Dynasty,was initially published as“A Treatise on Midwifery”in 1842 by William Lockhart,a British missionary to China.In 1894,John G.Kerr,an American missionary,translated the text as“The Tat Shang Pin”.This paper conducts a comparative study of the two English translations using a self-constructed English-Chinese parallel corpus of Da Sheng Bian.The study explores the translation styles of the two translators by examining the token-types ratio and frequency at the lexical level,mean sentence length at the syntactic level,and the use of conjunctions at the discourse level.The observed differences in translation styles between the two translations are analyzed in relation to the translators’backgrounds and translation strategies.
基金supported by the Institutional Fund Projects(IFPIP-1481-611-1443)the Key Projects of Natural Science Research in Anhui Higher Education Institutions(2022AH051909)+1 种基金the Provincial Quality Project of Colleges and Universities in Anhui Province(2022sdxx020,2022xqhz044)Bengbu University 2021 High-Level Scientific Research and Cultivation Project(2021pyxm04)。
文摘A dandelion algorithm(DA) is a recently developed intelligent optimization algorithm for function optimization problems. Many of its parameters need to be set by experience in DA,which might not be appropriate for all optimization problems. A self-adapting and efficient dandelion algorithm is proposed in this work to lower the number of DA's parameters and simplify DA's structure. Only the normal sowing operator is retained;while the other operators are discarded. An adaptive seeding radius strategy is designed for the core dandelion. The results show that the proposed algorithm achieves better performance on the standard test functions with less time consumption than its competitive peers. In addition, the proposed algorithm is applied to feature selection for credit card fraud detection(CCFD), and the results indicate that it can obtain higher classification and detection performance than the-state-of-the-art methods.
文摘本文探讨模糊法则的翻译应用价值,旨在为模糊语言的分析提供一个可以参考的模板。文章首先从模糊语言学(包括模糊语义学和模糊语用学)、模糊美学、模糊逻辑学、模糊数学、模糊修辞学五个维度,对"模糊"概念的界定进行回顾和分析,并提出翻译学中最宜采取的解释。然后,文章以The Da Vinci Code为个案,从语言时空、文化时空、修辞时空层面切入,探索文本中模糊语言所表现出的形式特点以及翻译处理所采取的对策。
基金This work was financially suppo.rted by the National Natural Science Foundation of China （No. 40372038 and No. 40325006） Special Grant of 0il ＆ Gas Research （XQ-2004-07）.
文摘Mesozoic bimodal volcanic rocks of basaltic andesite and rhyolite are widely distributed in the Da Hinggan Range, but their petrogenetic relationships and geodynamic implications are rarely constrained. Detailed studies on doleritic and porphyry dikes in the Zhalantun area indicate that they display features of magma mixing, suggesting their coeval formation. In situ zircon U-Pb dating shows that the porphyry was emplaced in the Early Cretaceous with a ^206Pb/^238U age of 130±1 Ma. Zircons from the dolerite also yield an Early Cretaceous emplacement age of 124±2 Ma although some inherited zircons have been identified. These age results indicate that the Early Cretaceous was an important period of magmatism in the Da Hinggan Range. Zircons from porphyry are characterized by positive value of εHf（t） as high as 10.3±0.5 with Hf depleted mantle model age of 349-568 Ma, whereas magmatic zircons from the dolerite have εHf（t） value of 11.0±1.4 with Hf depleted mantel model age of 342-657 Ma, consistent with those from the porphyry. Considering other data on the geological evolution of this area, it is concluded that the mafic magma originated from the partial melting of Paleozoic enriched lithospheric mantle, whereas the felsic magma came from recycling of juvenile crust formed during the Paleozoic. Both of the protoliths are closely related to the subduction of the Paleo-Asian Ocean during the Paleozoic, indicating that the Paleozoic is an important period of large-scale crustal growth in the area.
基金supported financially by the National Natural Science Foundation of China(Grants 49672156 and 49872079)awarded to Sao Ji’anthe National High Technology Research and Development Project(863-820-01-04)awarded to Liu Futian.
文摘High-resolution tomographic images of the belt crossing the Japan Trench-Changbai Mountains-Dong Ujimqin Qi are represented in this paper, revealing the shape of a subducted slab in the western Pacific region and characteristics of the lithospheric structures under the Changbai Mountains and the Da Hinggan Mountains. Studies of the spatial distribution, subduction time and the time-lag between the subduction and magmatism, combined with petrology and isotope geochemistry of the Late Mesozoic volcano-plutonic rocks from the Da Hinggan Mountains-Yanshan Mountains have further proved the independence of magmatic activities from the subduction of the Pacific plate. The Mesozoic tectono-thermal evolutionary history and structural characteristics of the lithosphere in the Da Hinggan Mountains and North China suggest that the formation and evolution of magma have probably a close relationship with the delamination and thinning of the continental lithosphere and the underplating resulting from the consequent upwelling of the asthenosphere. On the other hand, the large-scale strike-slip fault system, resulting from sinistral shearing of the Pacific plate relative to the Asian continent in the Mesozoic, is responsible for the formation and emplacement of magma on the continental margin. It was the intense crust-mantle interaction, together with structural deformation at the shallower levels that led to the large tectono-magmatic belt in the East Asian continental margin.
基金This work was financially supported by the National Natural Science Foundation of China(Grant No.49772134).
文摘The question whether there have been Quaternary glaciations in the Da Hinggan area has puzzled glacial geologists for many years because no sufficient glacial evidence has been found in this area. The study of Quaternary glaciers in the Da Hinggan area is also a key issue of the glaciology in China because of the special location of this area. In the past two years, a large number of complete and typical glacial vestiges have been found in Hexigten in the southern Da Hinggan Mountains, such as fossil cirque groups, horns, knife-edge crests, terminal moraines, glacial stepped stones. These landforms are located at a watershed, which are thus impossible to be formed due to tectonic processes, water or weathering, but can only be formed by glaciation. The calculated flat indexes of the fossil cirques in the Hexigten are 1.7-4.5, 4-5 and 1.3-5, which are within the range of 1.7-5 that is the flat index of real cirques. The typical and complete moraines have also been found in this area. All these glacial vestiges prove that the Quaternary glaciers did exist in the Da Hinggan Mountains of eastern China. Thus, it is of important scientific significance for the research on Chinese, even the global climatic and environmental evolution since the Quaternary.
基金financially supported by the National Natural Science Foundation of China (No. 40972065)the Special Project (No. XDA08100500) of the Chinese Academy of Science
文摘The Bianbianshan deposit, the unique gold-polymetal （Au-Ag-Cu-Pb-Zn） veined deposit of the polymetal metallogenic belt of the southern segment of Da Hinggan Mountains mineral province, is located at the southern part of the Hercynian fold belt of the south segment of Da Hinggan Mountains mineral province, NE China. Ores at the Bianbianshan deposit occur within Cretaceous andesite and rhyolite in the form of gold-bearing quartz veins and veinlet groups containing native gold, electrum, pyrite, chalcopyrite, galena and sphalerite. The deposit is hosted by structurally controlled faults associated with intense hydrothermal alteration. The typical alteration assemblage is sericite ＋ chlorite ＋ calcite ＋ quartz, with an inner pyrite-sericite-quartz zone and an outer seicite - chlorite - calcite-epidote zone between orebodies and wall rocks. δ34 S values of 17 sulfides from ores changing from -1.67 to ＋0.49‰ with average of -0.49‰, are similar to δ34 S values of magmatic or igneous sulfide sulfur. 206Pb/204Pb, 207Pb/204Pb and 208Pb/ 204Pb data of sulfide from ores range within 17.66-17.75, 15.50-15.60, and 37.64-38.00, respectively. These sulfur and lead isotope compositions imply that ore-forming materials might mainly originate from deep sources. H and O isotope study of quartz from ore-bearing veins indicate a mixed source of deep-seated magmatic water and shallower meteoric water. The ore formations resulted from a combination of hydrothermal fluid mixing and a structural setting favoring gold-polymetal deposition. Fluid mixing was possibly the key factor resulting in Au-Ag-Cu-Pb-Zn deposition in the deposit. The metallogenesis of the Bianbianshan deposit may have a relationship with the Cretaceous volcanic-subvolcanic magmatic activity, and formed during the late stage of the crust thinning of North China.
文摘Eclogite was firstly discovered at the Da Qaidam region (Yang,et al., 1998), and then in the Xitieshan and Dulan regions in 1999, constituting an over 350km long high\|pressure metamorphic belt in the northeastern Qinghai—Tibet plateau. Eclogites occur as pods in the garnet\|muscovite gneiss of the Dakendaban Group (or called Shaliuhe Group in Dulan) of Upper Proterozoic age. In general, the pods of eclogite vary in size; most of them are less than 20m×10m, some large ones up to about 100m×50m. The eclogite\|hosted gneiss is pale\|gray in color, consisting mainly plagioclase and quartz, and minor muscovite (5%～10% in vol.) and garnet (1%～2%). Some of the country rocks of eclogite are mica\|quartz\|(feldspar) schist, quartzite, and ultramafic rocks, the latter also occur in blocks.Over 50 pods were found in a belt of 10km×3km in the Da Qaidam region (No.1 location). Only a few pods of eclogite were found in the Xitieshan region in 1999 field expedition (No.2 location). Eclogite in Dulan occurs in the Proterozoic strata of Shaliuhe Group (same as the Dakendaban Group but with a different name). The eclogites in the Dulan region (No.3 location) expose about 10km wide in SN and an unknown length in EW, and can be subdivided into two belts, the North Eclogite Belt of Dulan (NEBD) and the South Eclogite Belt of Dulan (SEBD).
基金co-supported by the National Natural Science Foundation Project (No.40872137,40372103)Crisis Mines Study Project (No.20089948)Inner Mongolia Geological Exploring Important Project (No.2004-05)
文摘Mantle branch structure is the third tectonic unit of multiple evolution of a mantle branch. It is not only the main mechanism of intercontinental orogeny, but also an important ore-forming and ore-control structure. Studies on geotectonic evolution, regional geological characteristics and oreforming and ore-control structures have shown that since the Mesozoic the Da Hinggan Mts. region has entered a typical intercontinental orogenic stage, and it is closely related to mantle branch activities. The south-central segment of the Da Hinggan Mts. is a typical mantle branch structure and possesses obvious magmatic-metamorphic complexes in the core, detachment slip beds in the periphery and overlapped fault depression basins. Moreover, all of these are the principal factors leading to ore formation and ore control in the region. This paper also further explores the mechanism of mineralization in the south-central segment of the Da Hinggan, summaries the rules of mineralization, puts forward the models of mineralization and points out future ore-exploring orientation.
基金the auspices of the National Natural Science Foundation of China(No.41571152,41771179)the Social Science Foundation of Jilin Province,China(No.2019B56)。
文摘Following the trends of Chinese rural transformation development, and the sustainable development goals for resources and environment, reasonable arranging the potential development space and the ecological space, so as to optimize the distributions of rural settlement would be the key challenge for rural areas in ecologically fragile regions. From the perspective of maintaining regional ecological security, this paper takes Da’an City, a typical ecological fragile region in Jilin Province, as the case area, constructing the comprehensive ecological security pattern(ESP) on basis of landscape ecology, and applying the landscape pattern indexes to quantitative analysis the spatial distribution characteristics of rural settlements. Then, different optimization directions and management strategies are put forward for rural settlements in each secure zone under the comprehensive ESP. The experimental results showed that 1) the area of the low security zone, the general security zone, the moderate security zone and the extreme security zone was 1570.18 km^2, 1463.36 km^2, 1215.80 km^2 and 629.77 km^2, representing 32.18%, 29.99%, 24.92% and 12.91% of the total area of the target area, respectively. 2) The rural settlements in Da’an City were characterized by a high degree of fragmentation with a large number of small-scale patches. 3) The area of rural settlements in the ecological relocation zone, the in situ remediation zone, the limited development zone and the key development zone was 22.80 km^2, 42.31 km^2, 36.28 km^2 and 19.40 km^2, accounting for 18.88%, 35.03%, 30.04% and 16.06% of the total area of rural settlements, respectively. Then, different measures were proposed for settlements in different optimization zones in order to scientifically plan important ecological space, production space and living space in rural areas. This paper aims to provide fundamental support for rural settlements based on redistribution from the perspective of landscape ecology and provide insights for rural planning and rural habitat environmental improvement.
文摘Physicochemical parameters of mineralization such as temperature, pressure, salinity, density, composition and boiling of ore fluids as well as pH, Eh, fo2 and reducing parameter in theprocess of mineralization of major ore deposits in the study district have been obtained by the authors through systematic observation and determination of characteristics and phase changes of fluid inclusions at different temperatures and analysis of gaseous and liquid phase compositions of the inclusions, thus providing a scientific basis for the division of mineralization-alteration stages, types of mineral deposits and minerogenetic series and the deepening of the knowledge about the ore-forming processes and mechanisms of mineral deposits. It is indicated that the deposits of the same type have similar fluid inclusion geochemical features and physicochemical parameters though they belong to different minerogenetic series, while the compositions of inclusions are not conditioned by deposit types but closely related to the minerogenetic series of deposits.
基金supported by the resource compensation of Heilongjiang Province(Grant Nos.SDK2010-25)the Special Scientific Research Fund of Public Welfare Profession of China(Grant Nos.201211008)
文摘Whole-rock geochemical, zircon U-Pb geochronological and Sr-Nd-Hf isotopic data are presented for the Early Cretaceous volcanic rocks from the northern Da Hinggan Mountains. The volcanic rocks generally display high SiO2 （73.19-77.68 wt%） and Na20＋K20 （6.53-8.98 wt%） contents, with enrichment in Rb, Th, U, Pb and LREE, and depletion in Nb, Ta, P and Ti. Three rhyolite samples, one rhyolite porphyry sample, and one volcanic breccia sample yield weighted mean 206pb/23SU ages of 135.1±1.2 Ma, 116.5±1.1 Ma, 121.9±1.0 Ma, 118.1±0.9 Ma and 116.9±1.4 Ma, respectively. All these rocks have moderate （STSr/S6Sr）i values of 0.704912 to 0.705896, slightly negative eNd（t） values of -1.4 to -0.1, and positive Cur（t） values of 3.7 to 8. Their zircon Hf and whole-rock Nd isotopic model ages range from 594 to 1024 Ma. These results suggest that the Early Cretaceous volcanic rocks were originated from melting of subducted oceanic crust and associated sediments during the closure of the Mongol-Okhotsk Ocean.
