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Automatic Extraction Method of 3D Feature Guidelines for Complex Cultural Relic Surfaces Based on Point Cloud 被引量:1
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作者 GENG Yuxin ZHONG Ruofei +1 位作者 HUANG Yuqin SUN Haili 《Journal of Geodesy and Geoinformation Science》 CSCD 2024年第1期16-41,共26页
Cultural relics line graphic serves as a crucial form of traditional artifact information documentation,which is a simple and intuitive product with low cost of displaying compared with 3D models.Dimensionality reduct... Cultural relics line graphic serves as a crucial form of traditional artifact information documentation,which is a simple and intuitive product with low cost of displaying compared with 3D models.Dimensionality reduction is undoubtedly necessary for line drawings.However,most existing methods for artifact drawing rely on the principles of orthographic projection that always cannot avoid angle occlusion and data overlapping while the surface of cultural relics is complex.Therefore,conformal mapping was introduced as a dimensionality reduction way to compensate for the limitation of orthographic projection.Based on the given criteria for assessing surface complexity,this paper proposed a three-dimensional feature guideline extraction method for complex cultural relic surfaces.A 2D and 3D combined factor that measured the importance of points on describing surface features,vertex weight,was designed.Then the selection threshold for feature guideline extraction was determined based on the differences between vertex weight and shape index distributions.The feasibility and stability were verified through experiments conducted on real cultural relic surface data.Results demonstrated the ability of the method to address the challenges associated with the automatic generation of line drawings for complex surfaces.The extraction method and the obtained results will be useful for line graphic drawing,displaying and propaganda of cultural relics. 展开更多
关键词 point cloud conformal parameterization vertex weight surface mesh cultural relics feature extraction
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Natural Disaster Risk Monitoring for Immovable Cultural Relics Based on Digital Twin 被引量:1
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作者 LI Bolun DONG Youqiang +2 位作者 QIAO Yunfei HOU Miaole WEN Caihuan 《Journal of Geodesy and Geoinformation Science》 CSCD 2024年第1期90-104,共15页
Natural disaster risk monitoring is an important task for disaster prevention and reduction.In the case of immovable cultural relics,however,the feedback mechanism,risk factors,monitoring logic,and monitoring indicato... Natural disaster risk monitoring is an important task for disaster prevention and reduction.In the case of immovable cultural relics,however,the feedback mechanism,risk factors,monitoring logic,and monitoring indicators of natural disaster risk monitoring are complex.How to achieve intelligent perception and monitoring of natural disaster risk for immovable cultural relics has always been a focus and a challenge for researchers.Based on the analysis of the concepts and issues related to the natural disaster risk of immovable cultural relics,this paper proposes a framework for natural disaster risk monitoring for immovable cultural relics based on the digital twin.This framework focuses on risk monitoring,including the physical entities of natural disaster risk for immovable cultural relics,monitoring indicators,and virtual entity construction.A platform for monitoring the natural disaster risk of immovable cultural relics is proposed.Using the Puzhou Ancient City Site as a test bed,the proposed concept can be used for monitoring the natural disaster risk of immovable cultural relics at different scales. 展开更多
关键词 immovable cultural relics natural disaster risk digital twin risk monitoring
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Analysis on the Development Model of Relic and Museum Tourism Products Based on ERP Analysis:A Case Study on Shandong Province
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作者 WANG Xia 《Journal of Landscape Research》 2024年第1期77-82,共6页
In recent years, the trend of people choosing relic and museum tourism during their vacationand leisure time is growing day by day, mainly because it touches people's feelings about historical relicsand cultural h... In recent years, the trend of people choosing relic and museum tourism during their vacationand leisure time is growing day by day, mainly because it touches people's feelings about historical relicsand cultural heritage. The development of relic and museum tourism products is not only the inheritanceof culture and the protection of cultural relics, but also the promotion of tourism consumption under thebackground of cultural tourism integration, which has promoted the development of regional economy.With the relic and museum tourism resources in Shandong Province as the research object, through theanalysis of its resources, market and products, this paper put forward three applicable modes of relic andmuseum tourism product development, including independent development, joint development, and artauthorization, and proposed specific suggestions around the three modes. 展开更多
关键词 ERP analysis relic and museum tourism Product development Shandong Province
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Sanxingdui Cultural Relics Recognition Algorithm Based on Hyperspectral Multi-Network Fusion 被引量:1
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作者 Shi Qiu Pengchang Zhang +3 位作者 Xingjia Tang Zimu Zeng Miao Zhang Bingliang Hu 《Computers, Materials & Continua》 SCIE EI 2023年第12期3783-3800,共18页
Sanxingdui cultural relics are the precious cultural heritage of humanity with high values of history,science,culture,art and research.However,mainstream analytical methods are contacting and detrimental,which is unfa... Sanxingdui cultural relics are the precious cultural heritage of humanity with high values of history,science,culture,art and research.However,mainstream analytical methods are contacting and detrimental,which is unfavorable to the protection of cultural relics.This paper improves the accuracy of the extraction,location,and analysis of artifacts using hyperspectral methods.To improve the accuracy of cultural relic mining,positioning,and analysis,the segmentation algorithm of Sanxingdui cultural relics based on the spatial spectrum integrated network is proposed with the support of hyperspectral techniques.Firstly,region stitching algorithm based on the relative position of hyper spectrally collected data is proposed to improve stitching efficiency.Secondly,given the prominence of traditional HRNet(High-Resolution Net)models in high-resolution data processing,the spatial attention mechanism is put forward to obtain spatial dimension information.Thirdly,in view of the prominence of 3D networks in spectral information acquisition,the pyramid 3D residual network model is proposed to obtain internal spectral dimensional information.Fourthly,four kinds of fusion methods at the level of data and decision are presented to achieve cultural relic labeling.As shown by the experiment results,the proposed network adopts an integrated method of data-level and decision-level,which achieves the optimal average accuracy of identification 0.84,realizes shallow coverage of cultural relics labeling,and effectively supports the mining and protection of cultural relics. 展开更多
关键词 SANXINGDUI cultural relic spatial features spectral features HYPERSPECTRAL INTEGRATION
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Prediction of Chemical Composition of Ancient Glass Relics before Weathering
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作者 Jiehua Sun Huazhou Chen +3 位作者 Yao Liu Hongquan Lin Huiwen Zheng Yingzhen Qiu 《Open Journal of Applied Sciences》 2023年第9期1565-1580,共16页
Ancient glass relics are easily weathered by the influence of buried environment, and the internal elements exchange with the environmental elements in large quantities, resulting in changes in their composition ratio... Ancient glass relics are easily weathered by the influence of buried environment, and the internal elements exchange with the environmental elements in large quantities, resulting in changes in their composition ratio. Archaeological research can often detect the component content of glass relics after weathering, but it is difficult to obtain the corresponding component content before weathering. It is necessary to predict the chemical composition of glass relics before weathering in order to accurately identify the type of glass relics and repair them. To solve this problem, this paper proposes a distributed matching strategy, and studies the influence of weathering on the composition content of glass through compositional correlation analysis and linear regression statistical methods, so as to build a prediction model of the composition content of glass relics before weathering. The results show that the composition prediction model of glass cultural relics constructed by the distribution matching strategy has a good prediction ability, which is consistent with the change trend of the composition ratio of linear regression analysis. Moreover, the model is simple and easy to operate, which is convenient for popularization and application, and provides theoretical basis and reference value for further research on the composition and accurate classification of glass cultural relics. 展开更多
关键词 Glass relics WEATHERING Chemical Composition Correlation Analysis Distribution Matching Model Prediction
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Scientists Give Advice for China’s Fourth Survey of Cultural Relics
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《Bulletin of the Chinese Academy of Sciences》 2023年第4期198-198,共1页
China has launched its fourth national survey of cultural relics,an effort to catalog and protect ancient sites,tombs,buildings,and artifacts of historical and artistic significance.The previous surveys in 1956,1981,a... China has launched its fourth national survey of cultural relics,an effort to catalog and protect ancient sites,tombs,buildings,and artifacts of historical and artistic significance.The previous surveys in 1956,1981,and 2007 focused on documenting the condition and ownership of relics.To better protect cultural relics,develop their cultural value. 展开更多
关键词 significance relicS ANCIENT
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Glacier Relics of the Last Glacial and Holocene Periods Discovered in the Middle-low Mountains of Eastern China: Sedimentary Sequences and Environmental Evolution of Mengshan Mountain in Shandong Province since 80 ka 被引量:8
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作者 WANG Zhaobo WANG Jiangyue +1 位作者 HE Lelong ZHANG Jian 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2020年第1期141-151,共11页
The goal of this research study is to describe academic issues which have been debated in the field of Chinese geosciences for a century. In 1922, Jonquei S. Lee(Li Siguang) discovered Quaternary glacial relics at Tai... The goal of this research study is to describe academic issues which have been debated in the field of Chinese geosciences for a century. In 1922, Jonquei S. Lee(Li Siguang) discovered Quaternary glacial relics at Taihang Mountainin eastern China. In 1947, he published his research findings in the magazine Mount Lushan in Glacial Age. The research results had established three Ice Ages: Poyang(Gonzi), Dagu(Minde), and Lushan(Lisi). However, at that time, no Wurm glacial relics of the last Ice Age had been found in Lushan Mountain. Since then, the research team represented by Shi Yafeng, who is considered to be "the father of glaciers in China", questioned Jonquei S. Lee’s research results and concluded that "Professor Jonquei S. Lee’s Quaternary glacier research in Lushan Mountain having misread the debris flow". In 2005, the "middle-low mountains" in eastern China were finally defined as follows: "We clearly and unambiguously believe that there were no glacial activities in the middle-low mountainous areas of eastern China(east of 102° to 104°E;below 3,000 and 2,500 m) during the Quaternary Period". Currently, the long-standing academic debate appears to have come to a conclusion. As of 2015, the author and others began to investigate and study the Quaternary glacial relics in Mengshan Mountain(1,156 m above sea level), Shandong Province, one of the "middle-low mountains" of eastern China. The relics have been observed to posses the systematic features of glacial erosion, trough and valley striations, and moraine deposits. The applied dating method shave confirmed that there were not only glacial relics of the last Ice Age(Wurm), but also Holocene glacial relics in the Mengshan Mountain area. Therefore, in order to further establish the corresponding relationship between the glacier, loess, stream sediment series, and MIS in the Mengshan Mountain area, a large number of chronological studies have been carried out regarding the various types of sediments in the area, and 24 dating datahave been obtained using OSL, CRN, and 14 Cmethods.On this basis, the corresponding relationship between the sedimentary sequences and the MIS was established for the first time in eastern China, which in dicates the environmental changes which had occurred in eastern China since 80 ka. These discoveries s and chronological study results confirm the existence of the Last Ice Age, as well as Holocene glacial relics at Mengshan Mountain, there by confirming that Quaternary glaciation had occurred in the middle-low mountain areas of eastern China. 展开更多
关键词 OSL CRN MIS GLACIAL relicS last Ice Age HOLOCENE Eastern China
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Relic UHP Structures in Dabie-Sulu Region, China: Structural Expression and Geodynamic Significance 被引量:5
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作者 Suo Shutian Zhong Zengqiu You Zhendong Zhou Hanwen Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074, China 《Journal of Earth Science》 SCIE CAS CSCD 2000年第3期40-46,共7页
The present day observed tectonic framework of ultrahigh pressure (UHP) metamorphic belt in the Dabie Sulu region was dominantly formed by an extensional process at 200-170 Ma, under amphibolite facies conditions, f... The present day observed tectonic framework of ultrahigh pressure (UHP) metamorphic belt in the Dabie Sulu region was dominantly formed by an extensional process at 200-170 Ma, under amphibolite facies conditions, following the Triassic collision between the Sino Korean and Yangtze cratons. UHP relic structures, including massive eclogites with a weak foliation, UHP shear zones and A type folds, that are preserved in less retrograde metamorphism and deformation overprinted eclogite lenses can be recognized using the tectonic analysis. Examples are drawn from the Chengmagang area and Hejiawan area, Hubei; Bixiling area, Anhui, and Donghai area, northern Jiangsu. A speculative kinematic model is proposed for the collision between the cratons based on the UHP relic structures studied, in combination with the data of petrography, geochronology and P T path of UHP metamorphic rocks in the studied region which were reported in literature. It is stressed that only the early UHP relic structures, particularly, regionally consistent foliation and stretching lineations, record and reflect the formation of the UHP metamorphic rocks, and the relative dynamic and kinematic process related to the Triassic NNE directed oblique collision between the Sino Korean and Yangtze cratons. 展开更多
关键词 UHP relic structure extensional process compressional regime stretching lineation Dabie Sulu region.
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Genetic variation in progenies of 23 relic trees of Metasequoia glyptostroboides in their original habitat 被引量:1
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作者 Ke-Bing DU Lin XU +1 位作者 Ming-He LI Bao-Xian SHEN 《Forestry Studies in China》 CAS 2013年第1期1-12,共12页
Seeds of 23 relic Metasequoia glyptostroboides trees were randomly collected from their original, natural opulations found in Lichuan City, Hubei Province, China. The seed characteristics and growth of their three-yea... Seeds of 23 relic Metasequoia glyptostroboides trees were randomly collected from their original, natural opulations found in Lichuan City, Hubei Province, China. The seed characteristics and growth of their three-year-old rogenies were investigated. Results show that the average intra-family coefficient of variation (CV) in height growth of :he 23 three-year-old families was 14.53%, slightly higher than that of the inter-family CV (14.02%). Correspondingly, hese two parameters for root-collar diameter growth were 15.44% and 13.15%. The 23 relic mother trees were ignificantly differed in their general combining abilities (GCA) and relative effect values of GCA (RGCA) of height growth and root-collar diameter growth over the three years. Both height and root-collar diameter growth had high amily heritability in this seedling stage. After eliminating two inferior families, i.e., 15 and 46, 2.21% of genetic gain in he ght growth was obtained and 1.50% in root-collar diameter growth. It was also significantly different in crown size and number of branches among the 23 three-year-old seedling families. From a cluster analysis we concluded that eight families, i.e., 23, 28, 29, 30, 31, 33, 35 and 44 displayed superior GCA and RGCA in both height and root-collar diameter growth. Therefore, these relic mother trees displayed their potential as parents in seed orchards. With the exception of family 23, the other seven superior families were all collected at Guihua Village, Zhonglu Town, Lichuan City, which has been identified as an optimum district of M. glyptostroboides for seed collection. 展开更多
关键词 general combining abilities growth HERITABILITY Metasequoia glyptostroboides relic mother trees
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A New Theoretical Technique for the Measurement of High-Frequency Relic Gravitational Waves 被引量:3
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作者 R. Clive Woods Robert M L Baker +3 位作者 Fangyu Li Gary V Stephenson Eric W Davis Andrew W Beckwith 《Journal of Modern Physics》 2011年第6期498-518,共21页
Under most models of the early universe evolution, high-frequency gravitational waves (HFGWs) were produced. They are referred to as “relic” high-frequency gravitational waves or HFRGWs and their detection and measu... Under most models of the early universe evolution, high-frequency gravitational waves (HFGWs) were produced. They are referred to as “relic” high-frequency gravitational waves or HFRGWs and their detection and measurement could provide important information on the origin and development of our Universe – information that could not otherwise be obtained. So far three instruments have been built to detect and measure HFRGWs, but so far none of them has achieved the required sensitivity. This paper concerns another detector, originally proposed by Baker in 2000 and patented, which is based upon a recently discovered physical effect (the Li effect);this detector has accordingly been named the “Li-Baker detector.” The detector has been a joint development effort by the P. R. China and the United States HFGW research teams. A rigorous examination of the detector’s performance is important in the ongoing debate over the value of attempting to construct a Li-Baker detector and, in particular, an accurate prediction of its sensitivity in the presence of significant noise will decide whether the Li-Baker detector will be capable of detecting and measuring HFRGWs. The potential for useful HFRGW measurement is theoretically confirmed. 展开更多
关键词 HIGH-FREQUENCY GRAVITATIONAL WAVES HIGH-FREQUENCY relic GRAVITATIONAL Wave Measurement Primordial GRAVITATIONAL WAVES Microwaves COSMOLOGY General RELATIVITY
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Value Analysis of Immovable Cultural Relics from Landscape Perspective 被引量:1
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作者 ZHANG Yi QIU Jian 《Journal of Landscape Research》 2017年第3期57-63,66,共8页
This paper started by defining immovable cultural relics and landscape, and explicitly classified cultural relics under landscape. Then it analyzed the scientific value, artificial value, and historical value of cultu... This paper started by defining immovable cultural relics and landscape, and explicitly classified cultural relics under landscape. Then it analyzed the scientific value, artificial value, and historical value of cultural relics based on the angle of landscape. All these values had been changed and were indicated cultural value, aesthetic value and resource value as new values. The cultural value included identification with culture, inherited culture and educational value. The content of aesthetic value contained visual aesthetics and enjoyment. The resource value which was composed of the essence, space-time and scarcity, was revealed economic value, which was composed of environmental value and tourism value. In the following, the values of landscape and the new identified values of cultural relic were compared together to discover the connections between them. Finally, the new values of cultural relic were established under the angle of landscape which was composed of 4 degrees. 展开更多
关键词 CULTURAL HERITAGE Immovable CULTURAL relicS LANDSCAPE VALUE
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Constructing Teaching Model for Training English Guides of Stone Inscription Relics 被引量:2
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作者 李慧 《海外英语》 2016年第3期21-22,25,共3页
A teaching model based on constructivism is proposed in this paper. The model contains five teaching steps, e.g. interpretation teaching, questioning- dialogue, knowledge and skills teaching, discussion- collaboration... A teaching model based on constructivism is proposed in this paper. The model contains five teaching steps, e.g. interpretation teaching, questioning- dialogue, knowledge and skills teaching, discussion- collaboration and field training. Practice proves that it can effectively improve the training efficiency of the training of English guides of stone inscription relics and enhance their interpretation quality and English skills. 展开更多
关键词 CONSTRUCTIVISM stone INSCRIPTION relicS ENGLISH GUIDES TRAINING teaching model meaning construction
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Classification and Protective Measures of Geological Relics Based on Tourist Perception and Evaluation Perspective
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作者 Yonggang An,Heping Zhang,Tongde Li,Yunting Lu Life Science and Technology College,Central South University of Forestry and Technology,Changsha 410004,China. 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期297-297,共1页
The existing studies of geological relics have formed a classification system,which is based on geological relic cause factors.According to the geological relics of the tourist conception and perspective of tourism ev... The existing studies of geological relics have formed a classification system,which is based on geological relic cause factors.According to the geological relics of the tourist conception and perspective of tourism evaluation examples from Hunan Province,the author proposed the 展开更多
关键词 TOURIST CONCEPTION EVALUATION GEOLOGICAL relicS protective measures
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Can Thermal Input from a Prior Universe Account for Relic Graviton Production? Implications for the Cosmological Landscape 被引量:1
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作者 Andrew W. Beckwith 《Journal of High Energy Physics, Gravitation and Cosmology》 2016年第3期344-361,共19页
The author presents how to make a link between the low temperature and low entropy of pre big bang state of cosmology as given by Carroll and Chen in 2005, to the quantum cosmology conditions predicted by Weinberg whe... The author presents how to make a link between the low temperature and low entropy of pre big bang state of cosmology as given by Carroll and Chen in 2005, to the quantum cosmology conditions predicted by Weinberg when the temperature reaches 10<sup>32</sup> degrees Kelvin. We do this bridge building in our model construction as a way to get about the fact that cosmological CMB is limited by a red shift about z = 1100, so in order to get our suppositions consistent with observations, we also examine what happens in our model when we introduce quantization via a shift in values of the Hartle-Hawking wave function from a lower value of nearly zero to one which is set via an upper bound of the Planck’s constant of the order of 360 times the square of the Planck’s mass. 展开更多
关键词 relic Graviton Production Cosmological Landscape
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Units 7 Cultural relics课本要点精练
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作者 余丽华 《中学生英语(高中版)》 2008年第28期9-10,48,共3页
一、单词拼写根据句意和首字母或汉语提示,写出句中所缺单词的完全形式。1.The c________exchange between the two countries will make them better under
关键词 单项填空 完成句子 Units 7 Cultural relics
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Improved calculation of relic gravitational waves
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作者 赵文 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第10期2894-2902,共9页
In this paper, we have improved the calculation of the relic gravitational waves (RGW) in two aspects. First, we investigate the transfer function by taking into consideration the redshift-suppression effect, the ac... In this paper, we have improved the calculation of the relic gravitational waves (RGW) in two aspects. First, we investigate the transfer function by taking into consideration the redshift-suppression effect, the accelerating expansion effect, the damping effect of free-streaming relativistic particles, and the damping effect of cosmic phase transition, and give a simple approximate analytic expression, which clearly illustrates the dependence on the cosmological parameters. Second, we develop a numerical method to calculate the primordial power spectrum of RGW in a very wide frequency range, where the observed constraints on ns (the scalar spectral index) and Ps(k0) (the amplitude of primordial scalar spectrum) and the Hamilton-Jacobi equation are used. This method is applied to two kinds of inflationary models, which satisfy the current constraints on ns, α(the running of ns) and r (the tensor-scalar ratio). We plot them in the r - Ωg diagram, where Ωg is the strength of RGW, and study their measurements from the cosmic microwave background (CMB) experiments and laser interferometers. 展开更多
关键词 relic gravitational waves INFLATION
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Ancient Cultural Relics in Cities and Environmental Art Design: Series I of Urban Public Environment Design
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作者 TANG Yonggang ZHANG Feng 《Journal of Landscape Research》 2015年第6期91-92,共2页
Buildings and spatial environment left by history record evolution traces of cities and significant events related to the cities, and as a particular carrier of culture, they are witnesses of city development, and sho... Buildings and spatial environment left by history record evolution traces of cities and significant events related to the cities, and as a particular carrier of culture, they are witnesses of city development, and show the later generations memories of the city history. In urban planning, historical images must be respected, the relation between ancient cultural relics and urban planning handled properly, city brand established, and city image improved. The author, on the basis of exploring signifi cance of urban ancient cultural relics, used practical cases to fi gure out approaches of preserving urban ancient cultural relics in urban planning. 展开更多
关键词 CITY Ancient cultural relics Environmental art Public space
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Relic Oceanic Crust at Sub-Arc Depth: An Example from UHP Eclogites Enclosed in Serpentinites from the Southwestern Tianshan, China
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作者 SHEN Tingting ZHANG Lifei +1 位作者 Joerg HERMANN LIU Fenglin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第S1期35-,共1页
Ultra-high pressure(UHP)eclogites that derive from subducted oceanic crust are rarely found at the Earth’s surface because they need to be enclosed in a buoyant host rock such as serpentinites that facilitate exhum... Ultra-high pressure(UHP)eclogites that derive from subducted oceanic crust are rarely found at the Earth’s surface because they need to be enclosed in a buoyant host rock such as serpentinites that facilitate exhumation(Hermann et al.,2000;Guillot et al.,2001).Under normal subduction geotherms,serpentinites break down just before UHP conditions are reached and therefore most of the exhumed eclogites representing subducted oceanic crust formed under fore-arc conditions.We investigated eclogite blocks enclosed into serpentinites that occur in the southwestern Tianshan oceanic subduction,China.A previous study proved that the serpentinites derive from altered oceanic crust and experienced UHP metamorphism at low temperatures of 510-530°C(Shen et al.,2015).Three relatively fresh eclogite samples were studied in detail.Sample 129-7 shows the retrograde mineral assemblage of amphibole+biotite+albite+chlorite+minor titanite and peak metamorphic relics of omphacite+garnet±chlorite.Sample C107-23 is mainly composed of amphibole+albite+chlorite+zoisite+muscovite+minor titanite as a retrograde assemblage and garnet+phengite as the peak metamorphic relics with omphacite only found as inclusions in garnet.Similar to sample C107-23,sample C11066 preserves large-grained euhedral to subhedral garnet relics with omphacite inclusions,and epidote,diopside,amphibole,muscovite,chlorite,albite and biotite are in the matrix belong to the retrograde assemblage.These three retrograde eclogite samples were modelled using thermodynamic calculations in the Mn NCKFMSHO(Mn O-Na;O-Ca O-K;O-FeO-Mg O-Al;O;-SiO;-H;O-Fe;O;)system.Based on the peak assemblage of omphacite+garnet and the crossing of the grossular and pyrope isopleths in garnet,peak P-T conditions of;60-470oC,28-29 kbar(129-7),450-500oC,28-35 kbar(C107-23),;75-505oC,26-29 kbar(C11066)were calculated.The retrograde assemblages indicate near isothermal decompression resulting in a clockwise P-T evolution of these eclogites.The peak metamorphic pressures at 500°C are well within UHP conditions(coesite stability field)and are within error the same as peak conditions of the host serpentinites(Shen et al.,2015).This provides evidence that eclogites and serpentinites shared the same evolution.We infer that the subducted low-density serpentinites were assembled with the high-density eclogites during subdution and helped the latter to exhume back to the surface.The studied eclogites thus represent rare examples of relics of oceanic crust that was subducted to sub-arc depth. 展开更多
关键词 UHP An Example from UHP Eclogites Enclosed in Serpentinites from the Southwestern Tianshan China relic Oceanic Crust at Sub-Arc Depth
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Breeding biology of a relictual Maghreb Magpie(Pica mauritanica)population in Tunisia
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作者 Aymen Nefla Ridha Ouni +1 位作者 Slaheddine Selmi Said Nouira 《Avian Research》 CSCD 2021年第1期28-36,共9页
Background:The Maghreb Magpie(Pica mauritanica)is an endemic North African species.Available knowledge on this species is limited to historic descriptive data with no ecological information provided.Populations contin... Background:The Maghreb Magpie(Pica mauritanica)is an endemic North African species.Available knowledge on this species is limited to historic descriptive data with no ecological information provided.Populations continue to dramatically decline in Tunisia,where only one relic population survives.Investigating the breeding biology of this species is essential for conservation purposes.The purpose of this study was to increase our understanding of the Tunisian relic population and provide detailed data on breeding biology over two breeding seasons(2017 and 2018).Methods:This study occurred on a private farm of 650 ha,located 10 km from Dhorbania village at Kairouan Governorate,in central Tunisia.Active nests were monitored weekly during egg laying period and twice a week during hatching period.The Ivlev's electivity index was used to assess whether the frequency of use of nesting trees and bushes matched their availability in the study area.We recorded nest measurements and positions,and compared them using Wilcoxon signed-rank test.Variations of breeding parameters as number of eggs laid,hatchlings,and fledglings over years were performed using Mann–Whitney U-test andχ^(2) tests.We used a Generalized Linear Mixed Model(GLMM)to investigate how egg volume varied with clutch size and laying date.Results:We investigated clutch size,egg size,hatching and fledging success,and evaluated how these parameters varied according to laying date and nest characteristics.Clutch size averaged 5.00±0.19 but was significantly greater nest.Causes of nest failure included the depredation of nestlings by shrikes,cobras and rats(e.g.Lanius meridionalis,Naja haje and Rattus rattus),death of parents by the Black-shouldered Kite(Elanus caeruleus)and nest parasitism by the Great Spotted Cuckoo(Clamator glandarius).Clutch size,brood size and fledgling success were unaffected by laying date,nest volume and nest elevation.Egg volume decreased with laying date but was unaffected by clutch.Conclusion:Our study provides the first and only detailed data on reproductive parameters of the Maghreb Magpie in its entire geographic range(North Africa).Information gleaned from this study provides valuable information for monitoring and long-term conservation plans of the endangered Tunisian Magpie population.Additionally,our data provide an avenue of large-scale comparative studies of the reproductive ecology of the magpie complex. 展开更多
关键词 Clutch size Laying date Maghreb Magpie Nesting habitat Nest success relic population Tunisia
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Relic Oceanic Crust at Sub-arc Depth: an Example from UHP Eclogites Enclosed in Serpentinites from the Southwestern Tianshan Mountains, China
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作者 SHEN T.T. ZHANG L.F. +1 位作者 LIU F.L HERMANN J. 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第S1期238-,共1页
Ultra-high pressure(UHP)eclogites that derive from subducted oceanic crust are rarely found at the Earth’s surface because they need to be enclosed in a buoyant host rock such as serpentinites that facilitate exhumation
关键词 UHP an Example from UHP Eclogites Enclosed in Serpentinites from the Southwestern Tianshan Mountains China relic Oceanic Crust at Sub-arc Depth
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