检索结果-南通市图书馆

Statistical analysis of geomagnetic field variations during the partial solar eclipse on 2011 January 4 in Turkey

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2015年第5期15卷 742-752页

作者： Abdullah Ates Yunus Levent Ekinci Aydin Buyuksarac Attila Aydemir Alper Demirci Ankara University Faculty of Engineering Department of Geophysical Engineering BesevlerTR-06100 Ankara Turkey Bitlis Eren University Faculty of Arts and Sciences Department of Archaeology TR-13000Bitlis Turkey Bitlis Eren University Faculty of Engineering and Architecture Department of Civil Engineering TR-13000 Bitlis Turkey Turkish Petroleum Corp. Sogutozu Mah. 2180. Cad. No: 10 Sogutozu TR-06100 AnkaraTurkey Bitlis Eren University Faculty of Engineering and Architecture Department of Geophysical Engineering TR-13000 Bitlis Turkey

Some geophysical parameters, such as those related to gravitation and the geomagnetic field, could change during solar eclipses. In order to observe geomagnetic fluctuations, geomagnetic measurements were carded out in a limited time frame during the partial solar eclipse that occurred on 2011 January 4 and was observed in Canakkale and Ankara, Turkey. Additionally, records of the geomagnetic field spanning 24 hours, obtained from another observatory （in Iznik, Turkey）, were also analyzed to check for any peculiar variations. In the data processing stage, a polynomial fit, following the application of a running average routine, was applied to the geomagnetic field data sets. Geomagnetic field data sets indicated there was a characteristic decrease at the beginning of the solar eclipse and this decrease can be well-correlated with previous geomagnetic field measurements that were taken during the total solar eclipse that was observed in Turkey on 2006 March 29. The behavior of the geomagnetic field is also consistent with previous observations in the literature. As a result of these analyses, it can be suggested that eclipses can cause a shielding effect on the geomagnetic field of the Earth.

关键词： Sun magnetic field -- eclipses -- methods data analysis -- methods statistics

Genomic consequences of population decline in critically endangered pangolins and their demographic histories

在线全文

学校读者我要写书评

暂无评论

National Science Review 2020年第4期7卷 798-814页

作者： Jing-Yang Hu Zi-Qian Hao Laurent Frantz Shi-Fang Wu Wu Chen Yun-Fang Jiang Hong Wu Wei-Min Kuang Haipeng Li Ya-Ping Zhang Li Yu State Key Laboratory for Conservation and Utilization of Bio-Resource in Yunnan School of Life Sciences Yunnan University State Key Laboratory of Genetic Resources and Evolution Kunming Institute of Zoology Chinese Academy of Sciences Kunming College of Life Science University of Chinese Academy of Sciences CAS Key Laboratory of Computational Biology CAS-MPG Partner Institute for Computational Biology Shanghai Institute of Nutrition and Health Chinese Academy of Sciences University of Chinese Academy of Sciences School of Biological and Chemical Sciences Queen Mary University of London The Palaeogenomics and Bio-archaeology Research Network Department of Archaeology University of Oxford Guangzhou Zoo Lushui Management and Conservation Branch of Gaoligong Mountain National Nature Reserve Center for Excellence in Animal Evolution and Genetics Chinese Academy of Sciences

Pangolins are among the most critically endangered animals due to heavy poaching and worldwide trafficking. However, their demographic histories and the genomic consequences of their recent population declines remain unknown. We generated high-quality de novo reference genomes for critically endangered Malayan(Manis javanica, MJ) and Chinese(M. pentadactyla, MP) pangolins and re-sequencing population genomic data from 74 MJs and 23 MPs. We recovered the population identities of illegally traded pangolins and previously unrecognized genetic populations that should be protected as evolutionarily distinct conservation units. Demographic reconstruction suggested environmental changes have resulted in a population size fluctuation of pangolins. Additionally, recent population size declines due to human activities have resulted in an increase in inbreeding and genetic load. Deleterious mutations were enriched in genes related to cancer/diseases and cholesterol homeostasis, which may have increased their susceptibility to diseases and decreased their survival potential to adapt to environmental changes and high-cholesterol diets. This comprehensive study provides not only high-quality pangolin reference genomes, but also valuable information concerning the driving factors of long-term population size fluctuations and the genomic impact of recent population size declines due to human activities, which is essential for pangolin conservation management and global action planning.

关键词： pangolins population genomics population declines genetic diversity inbreeding genetic load demographic history

A preliminary study of the weathering mechanism of fossilized Cretaceous Hamipterus bones

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2021年第3期64卷 458-469页

作者： Ying LI Wugan LUO Yimin YANG Shunxing JIANG Xiaolin WANG Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of SciencesBeijing100044China department of archaeology and Anthropology University of Chinese Academy of SciencesBeijing100049China CAS Center for Excellence in Life and Paleoenvironment Beijing100044China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing100049China

The discovery of Hamipterus tianshanensis had important scientific significance because three-dimensional preserved fossils can provide unique information about the reproduction,development,and evolution of ***,the pterosaur fossils exhibited violent weathering,including noticeable cracking and spalling,since the preservation environment changed dramatically after excavation,which severely influenced the preservation of these fossils and the scientific research conducted on *** determine the weathering mechanism of these fossil bones,the samples were analyzed using X-ray fluorescence(XRF),Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),scanning electron microscopy and energy dispersive spectrometry(SEM-EDS).The results indicate that calcite is the main mineral in the hollow bones,but it is mixed with a small amount of other minerals,such as quartz,feldspar,and other debris ***,the main component of the pterosaur bones is hydroxyapatite,and carbonate has substituted for some of the phosphate(B-type carbonated apatite)in the fossil bones.A small amount of calcite and manganese oxides has precipitated in the vascular *** phosphate crystallinity index(PCI)is *** results indicate that the fossils have undergone severe *** from these alterations,the fossil bones have high contents of anions and cations such as Cl^(-),NO_(3)^(-),SO_(4)^(2-),Na^(+),and Ca^(2+),and the total content of soluble salts is 35584.41μg g^(-1).Based on these results,it is inferred that the weathering mechanism of the fossil bones is as ***,the fragile hollow bones cracked easily because of the enormous thermal stress caused by the dramatic temperature changes in the Gobi Desert and the differences in the thermal expansion coefficients(TEC)of the surrounding rocks,the fossil bones,and the different ***,a large amount of stress is generated by salt crystallization when the temperature and humidity c

关键词： Hamipterus fossil weathering hydroxyapatite coefficient of thermal expansion Xinjiang

Analytical Study of Ground Painting Layers and Conservation Processes of an Egyptian Painted Coffin

在线全文

学校读者我要写书评

暂无评论

Journal of Life Sciences 2011年第8期5卷 661-669页

作者： Hala Afifi Mahmood Mostafa Ahmed AbdE1 Fatah Conservation and Restoration department Faculty of Archaeology Cairo University Giza Cairo 12613 Egypt Supreme Council of Antiquities Cairo 12613 Egypt

The aim of this study is to examine and present the results of the scientific examinations carried out on the ground layers with paint samples collected from the decorated surfaces of the wooden coffin dated back to the late period from Saqqara excavation that belonged to the Ministry of Antiquities. Many analytical methods were performed as optical microscopy, scanning electron microscopy coupled with energy-dispersive X-ray analysis （ESEM-EDX）, X-ray diffraction analysis as well as fourier transform infrared spectroscopy have been used to both characterise the inorganic composition and the binding media used. The analytical results showed that the materials composition and technique used to plaster applied on the wooden surface are in good agreement with the information gathered through the historical survey. The coffin was in bad and poor condition. There was cracking on the surface and in the structure, serious flaking, cupping of some pigments and serious damage in both the wooden support and gesso layer. Conservation treatment processes carried out included consolidation of lifting areas of the paint film, disturbing restoration materials, repair of cracks in the wooden support and a dry surface cleaning of the pigments.

关键词： Wooden coffin pigments Saqqara EDX SEM conservation chemical composition deterioration aspect.

Assessment of water-induced soil erosion as a threat to cultural heritage sites:the case of Chania prefecture,Crete Island,Greece

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Big Earth Data 2022年第4期6卷 561-579页

作者： Christos Polykretis Dimitrios D.Alexakis Manolis G.Grillakis Athos Agapiou Branka Cuca Nikos Papadopoulos Apostolos Sarris Laboratory of Geophysical-Satellite Remote Sensing and Archaeo-environment(Geosat ReSeArch) Institute for Mediterranean StudiesFoundation for Research and Technology-HellasCreteGreece School of Environmental Engineering Technical University of CreteChaniaCreteGreece department of Civil Engineering and Geomatics Cyprus University of TechnologyLimassolCyprus department of Architecture Built Environment and Construction EngineeringMilanItaly Digital Humanities Geoinformatics Lab Archaeological Research UnitDepartment of History and ArchaeologyUniversity of CyprusNicosiaCyprus

Among the environmental threats,the intensification of natural hazards,such as soil erosion may threaten the integrity and value of cultural heritage *** this framework,the present study’s main objective was to identify archaeological sites susceptible by soil erosion,taking the case study of Chania prefecture in Crete *** sensed and other available geospatial datasets were analyzed in a GIS-based empirical model,namely Unit Stream Power Erosion and Deposition(USPED),to estimate the average annual soil loss and deposition rates due to waterinduced erosion in the study *** resultant erosion map was then intersected with the locations and surrounding zones of the known archaeological sites for identifying the sites and the portions of their vicinity being at *** results revealed that Chania prefecture and its cultural heritage are significantly affected by both soil loss and deposition *** the two processes,soil loss was found to be more intensive,influencing a larger part of the prefecture(especially to the west)as well as a higher amount of archaeological *** extreme and high soil loss classes were also detected to cover the most considerable portion of the sites’surrounding *** identification of the archaeological sites being most exposed to soil erosion hazard can constitute a basis for cultural heritage managers in order to take preventive preserva-tion measures and develop specific risk mitigation strategies.

关键词： Cultural heritage soil erosion USPED model GIS Crete

Study of Preservation Status and Dietary Reconstruction in the Human Remains Recovered from Roopkund Lake through Chemical Analysis of Faunal Remains

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Chemistry and Chemical Engineering 2015年第1期9卷 15-22页

作者： Yogambar Singh Farswan Jaibir Singh department of History & archaeology H.N. Bahuguna Garhwal University Garhwal-246174 India department of History Bal Ganga Maha Vidhyala Sendul Garhwal-246174 lndia

Present study is carried out in the bone samples collected from Roopkund Lake in district Chamoli Garhwal, Uttarakhand which is located at 5,029 meters from main sea level in between Nanda Ghunghti and Trishuli peak. This historical site belongs to 9th century A.D. All the samples selected for the study were dried in room temperature as well as hot air oven at 32 ~C. Cleaning, pretreatment and digestion process of faunal remains was followed through established scientific methods. Chemical analysis i.e. concentration of different elements such as calcium, strontium, barium, magnesium and zinc as well as isotopic ratios of Carbon and Nitrogen was estimated with the help of ICP （inductively coupled plasma spectroscopy） and AAS （atomic absorption spectrophotometer）. The results obtained from the chemical analysis are significant. On the basis of concentration of different elements and ratios of Nitrogen and Carbon isotopes, the dietary habits of the peoples buried in the Roopkund Lake are identified, which is different from sample to sample person to person. Besides this, the results are also significantly helpful for knowing the preservation status of faunal remains in Roopkund Lake. Finally this study also indicated the potentiality of chemical analysis for reconstructing the palaeodiet behaviour and preservation status of bone remains.

关键词： Roopkund Lake dietary reconstruction chemical analysis faunal remains archaeological site.

Spatiotemporal variation of agricultural patterns in different geomorphologic and climatic environments in the eastern Loess Plateau,north-central China during the late Neolithic and Bronze Ages

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2022年第5期65卷 934-948页

作者： Haiming LI Yifu CUI Nathaniel JAMES Melissa RITCHEY Fengwen LIU Junna ZHANG Minmin MA Guanghui DONG College of Humanities&Social Development Nanjing Agricultural UniversityNanjing 210095China Institution of Chinese Agricultural Civilization Nanjing Agricultural UniversityNanjing 210095China Agricultural archaeology Research Center Nanjing Agricultural UniversityNanjing 210095China College of Tourism Huaqiao UniversityQuanzhou 362021China Ministry of Education Key Laboratory of Western China’s Environmental System College of Earth&Environmental SciencesLanzhou UniversityLanzhou 730000China department of Anthropology University of California San DiegoSan DiegoCA 92093USA department of Anthropology Washington University in St.LouisSt.LouisMO 63130USA Institute for Ecological Research and Pollution Control of Plateau Lakes School of Ecology and Environment ScienceYunnan UniversityKunming 650504China Laboratory for Environmental archaeology Archaeological Research CenterBeijing Union UniversityBeijing 100191China

Human settlement and agricultural development are closely linked to local geomorphological and climatic ***,the variation in agricultural systems in different environmental and prehistoric contexts remains *** report new archaeobotanical and radiocarbon dates from 34 Neolithic and Bronze Age sites in the Hutuo River Valley(HTRV)in north-central China and compare them with updated archaeobotanical studies in the Sushui River Valley(SSRV)and Henan Province(HNP),to explore the similarities and differences of agricultural patterns under different geomorphologic and climatic environments in north-central *** results reveal that humans consistently cultivated foxtail and broomcorn millet in the HTRV from the Miaodigou(6000–5700 cal.a BP)to the Shang-Zhou(3600–2256 cal.a BP)period,despite the introduction of wheat and barley into the area around 4000 a *** conditions and hilly landforms in the HTRV,SSRV and some parts of the HNP led people to develop foxtail and broomcorn millet dry land farming practices between 7000 and 3000 a ***,in other areas of the HNP,the climate conditions and alluvial plains enabled people to develop a mixed agriculture of millets,soybeans,and rice from 7000 to 4000 a BP,with the addition of wheat between 4000 and 3000 a ***’different agricultural technologies and interactions with foreign cultures may have also influenced the formation of different agricultural patterns in the three regions between 7000 and 3000 a *** growth during 7000–3000 a BP can explain the overall propensity of the higher-yield foxtail millet rather than broomcorn millet as the main cultivated *** the HTRV,however,higher proportions of broomcorn millet(as compared to the SSRV and HNP),may reflect the greater drought and heat tolerance of broomcorn millet,representing an adaptive agricultural strategy in the river valley.

关键词： Archaeobotanical Agricultural patterns Climate conditions Hilly area Alluvial plains

A Mega-Tsunami in the Baltic Sea 1171 BC: Geological Records with Special Reference to the Lake Mälaren Area in Sweden

在线全文

学校读者我要写书评

暂无评论

International Journal of Geosciences 2020年第10期11卷 667-707页

作者： Nils-Axel Mörner Björn Ambrosiani Phyllis Anderson Ambrosiani Paleogeophysics & Geodynamics Stockholm Sweden Swedish National Heritage Board Stockholm Sweden department of archaeology and Ancient History Uppsala University Uppsala Sweden

At about 3000 C14-year BP or 1200 cal. yrs BC, the Baltic Sea experienced a mega-tsunami with a wave-height of 10 m or more, and a run-up height of up to 16.5 m. This event had significant geological and archaeological effects. We explore the records from the Lake M?laren area in Sweden. The tsunami event is linked to seismic ground shaking and methane venting tectonics at several sites. The triggering factor is proposed to be the Kaali meteor impact in Estonia of the same age. The documentation of a mega-tsunami in the middle of the Bronze Age has wide implications both in geology and in archaeology. The archaeological key sites at Annelund and Apalle are reinterpreted in terms of tsunami wave actions remodelling stratigraphy. By extensive coring, we are able to trace the tsunami effects in both off-shore and on-shore environment. At the time of the event, sea level was at +15 m (due to isostatic uplift). The tsunami wave erosion is traced 13.5 m below sea level. The tsunami run-up over land is traced to +29.5 m to +31.5 m (occasionally even higher), implying a run-up of 14.5 - 16.5 m. In ?ngermanland, the tsunami event was absolutely dated at 1171 varve years BC. Archaeologically, the tsunami event coincides well with the transition between Periods II and III of the South Scandinavian Bronze Age. Period III has traditionally been difficult to identify in the cultural materials of the Lake M?laren region.

关键词： Tsunami Deposits Mega-Tsunami Wave Height and Run-Up Kaali Impact Archaeological Reinterpretations The Bronze Age Lake Mälaren Area Sweden

Starch grain evidence reveals early pottery function cooking plant foods in North China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2014年第32期59卷 4352-4358页

作者： Xiaoyan Yang Zhikun Ma Tao Wang Linda Perry Quan Li Xiujia Huan Jincheng Yu Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences University of Chinese Academy of Sciences School of Geography Beijing Normal University department of archaeology and Museology Capital Normal University The Foundation for Archaeobotanical Research in Microfossils Fairfax VA 22038 USA department of Geography and Geoinformation Science Center for Earth Observing and Space Research George Mason University Fairfax VA 22030 USA Beijing Institute of Cultural Relics

Early pottery sherds excavated in northern China date back to more than 11,000 cal a BP,and are presumed to have been used as cooking *** has been,however,no direct evidence to demonstrate this *** we report ancient starch grains recovered from carbonized residues adhering to the bases of flatbottomed vessels excavated from the Zhuannian site dating more than 10,000 cal a BP in the North China *** evidence demonstrates that early pottery was being used to cook cereal grains,particularly millets,and *** millets were in the process of domestication at thistime,we propose that pottery invention in northern China may have been related to early farming activities.

关键词：中国北方烹饪器皿淀粉粒植物性食物陶器早期证据 CAL