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31.
海洋出水的木质文物中通常会沉积硫铁化合物。打捞出水后,硫铁化合物遇到空气和水分后会发生氧化,生成硫酸以及各种硫酸盐,并引起有机质的降解。近年来,硫铁化合物对海洋出水木质文物的危害已引起广泛关注。为此,本工作阐述了硫铁化合物相关问题的研究现状,就硫铁化合物的产生原因、危害以及目前控制方法的研究进展进行了总结,同时评述了针对硫铁化合物的处理方法。  相似文献   
32.
ABSTRACT

As the title implies this special issue concentrates on the coconut in its older usages and its transformation into commodities. The coconut has many histories, with specific intersections with each Pacific island society, indeed each community and family. This brief introduction seeks to give an overview of its penetration into the lives and societies at several levels, from small clans to major companies, from growers to governments, all implicated along the commodity chain. In spite of the coconut’s ubiquity, the historiography has never addressed it fully but taken it rather as a given, one player in capitalism in the region, yet in fact, for over a hundred years, it was the star product upon which many governments and people across the tropical Pacific depended for income. We hope that some aspects of the coconut’s complexity and meaning are brought to light in the following new contributions to its history.  相似文献   
33.
J. Cao  W. Hu  X. Wang  D. Zhu  Y. Tang  B. Xiang  M. Wu 《Geofluids》2015,15(3):410-420
In this paper, we attempt to differentiate hydrocarbon‐bearing reservoir horizons of the Junggar Basin of NW China based on the characteristics of diagenesis and associated elemental geochemistry. Reservoirs at this site have varying levels of oil saturation that correlate with the degree of dissolution in minerals (e.g., calcite and feldspar). Four different horizons with varying diagenetic mineral assemblages were observed, including (i) kaolinite‐rich, oil‐dominated horizons, (ii) kaolinite–pyrite–hematite‐rich, oil–water‐dominated horizons, (iii) siderite–chlorite‐rich, water‐dominated horizons, and (iv) chlorite‐rich horizons with negligible hydrocarbon production. The mean MnO content of the representative diagenetic mineral (e.g., calcite) in each of the above horizons is >2.5, 2.0–2.5, 1.5–2.0, and <1.0 wt%, respectively. We propose that the above methodology can be used for the identification of reservoir hydrocarbon‐bearing horizons. We argue that the indicators presented here can be applied in oil exploration across the Junggar Basin.  相似文献   
34.
Human-induced global threats are compelling many anthropologists to rethink roles, methods, and paradigms and engage in public debate and action on energy policies, extraction processes, commodity chains, and consumption. Laura Nader's Energy Reader embodies her decades-long engagement as a catalyst for public debate on U.S. energy issues. Tanja Winther's Impact of Electricity exemplifies ethnography informing development practice. Strauss and colleagues’ Cultures of Energy reflects diverse approaches seeking to build cultural understandings to inform energy choices. There remains a need for collaboration with anthropologists embedded in energy-related agencies—positioned where they can leverage anthropological knowledge to push policy envelopes.  相似文献   
35.
A marine electric resistivity survey was carried out over a submerged beach along the Agropoli shore (Salerno, Italy) to detect buried objects of archaeological interest below the sandy seabed. We found a shipwreck, a military vessel that probably sunk during the Salerno landing operations of the allied forces in the Second World War. Resistivity data provide information on the vertical and horizontal extension of the shipwreck, which is characterized by very low calculated resistivity values (about 2–5 ohm m). Such values differ significantly from the sand and the bedrock values (5–40 ohm m). Although the presence of the shipwreck is clearly visible from geoelectric data, the joint application of electric, magnetic and multibeam bathymetric techniques reduces the ambiguities inherent in each method. As shown in the Electrical Resistivity Tomography (ERT) and confirmed by the Digital Elevation Model (obtained from the processing of bathymetric data), the shipwreck extends more than 30 m in NE–SW direction and it is about 13 m wide. The global extension of the relic is consistent with the magnetic data, that are characterized by a magnetic anomaly with an amplitude of about 1800 nT and similar dimension, as inferred from the estimation of source boundaries obtained from the computation of the analytic signal. The results of our survey encourage the use of marine geoelectrical methods for the detection of buried archaeological targets, particularly in locations where the use of seismic prospecting is not effective (e.g. very shallow water with sandy sea-bottoms). The integration of different geophysical methods allows to better define the extension, depth and thickness of buried objects, suggesting that such an approach is the most effective for underwater archaeological investigations.  相似文献   
36.
Kai Bosworth  Charmaine Chua 《对极》2023,55(5):1345-1367
Scholars argue that blockades of infrastructure pose an economic threat to capital circulation. This explains how activists can gain power through strategic spatial occupations and why states seek to protect “critical infrastructure” from disruption. However, Indigenous-led blockades of pipelines gain power not (only) by disrupting economic flows alone, but by eliciting state anxieties about the racialised political, psychic and economic project of settler colonialism. Analysing public discourse surrounding the Keystone XL and Dakota Access pipelines, including legislative measures introduced to criminalise protest since the blockade at Standing Rock, we reframe critical infrastructure security as a component operation of settler countersovereignty. The criminalisation of Indigenous dissent through the state’s escalation of protest legislation is an investment in maintaining settler political authority, leading us to conclude that blockades must be understood not only as a form of anti-capitalist resistance, but also as a locus of anti-colonial struggle.  相似文献   
37.
漆灰的修复是漆器文物修复工作的重要组成部分。为揭示故宫博物院旧藏漆器3种典型漆灰的材料构成及特点,以及为漆器修复工作提供科技支持,研究结合X射线荧光光谱、微区X射线衍射、红外光谱、纤维显微镜观测、热裂解-气相色谱/质谱联用等技术,综合分析了3种典型漆灰所含无机及有机原材料。研究结果表明:明代古梅花蕉叶式琴漆灰所用无机材料是动物角灰或骨灰及少量黏土,胶结材料则由中国大漆及少量植物油组成;清代黑漆描金大宝座漆灰的无机材料为含有方解石的黏土,胶结材料为熟桐油、猪血的混合物,此外,样品中还含有麻类纤维,为宝座木胎与漆灰层之间所裱麻布,宝座漆灰不但能提供平整髹漆表面,而且还对麻布有加固定型作用;清代黑漆地填金字张廷玉书圣训天伦对联漆灰的无机材料为黏土,胶结材料则为熟桐油、猪血的混合物。研究所用分析方法体系可实现漆灰原材料,特别是有机胶结材料的准确识别。3种典型漆灰的选材特点与中国古代漆器,特别是明清时期家具、器物制作用料传统相吻合,研究结果可直接应用于漆器文物修复方案的制定。  相似文献   
38.
The exploitation of marine resources in Prehistory has traditionally been regarded as insignificant, at least until the late Upper Pleistocene. However, in recent years the systematic study of archaeofaunal remains with a marine origin has widened our knowledge of the role they played among groups of hunter–gatherers in Europe. This paper analyses the available data about the evidence for the exploitation of the different marine resources (molluscs, birds, mammals, crustaceans, echinoderms and fish) that have been recorded at archaeological sites in Cantabrian Spain in the late Pleistocene and early Holocene.With the information currently available, it is clear that although it is in the Mesolithic when archaeozoological remains with a marine origin are found most often, the exploitation of these resources in the region began in the Early Upper Palaeolithic.  相似文献   
39.
To investigate potential human impacts on California Channel Island shellfish stocks over the past 10,000 years, we measured 1718 owl limpet shells from 19 archaeological components on San Miguel Island. Inhabiting the middle intertidal zone of Pacific Coast rocky shores, owl limpets are slow-growing mollusks that can live for 30 years and reach lengths of over 100 mm. Recent ecological studies indicate that owl limpets are highly susceptible to heavy human predation, which results in reduced mean shell sizes among Lottia populations along the coasts of Alta and Baja California. On San Miguel Island, we identified a significant trans-Holocene reduction in mean owl limpet size, beginning more than 6500 years ago and accelerating at least 4400 years ago. Fluctuations in limpet size show no clear correlation with changes in sea surface temperature and marine productivity, suggesting that increased predation by growing human populations was primarily responsible for the reduction in Lottia size over time. Our results provide further evidence that prehistoric peoples significantly influenced nearshore fisheries long before the development of the commercial and industrialized fisheries of historic times.  相似文献   
40.
This work presents the results of an investigation of the lacquer objects excavated from a Chu tomb in China (Warring States, 481–221 BC). This study is engaged in the examination of the methods and the materials used for the urushi coating on the objects. X-Ray fluorescence and Scanning Electron Microscopy/Energy Dispersive Using X-Ray (SEM/EDX) analyses were applied for the pigment identification. The results show that vermilion was for the red colour, while carbon black was for the black colour. Pyrolysis gas chromatography and mass spectrometry (Py-GC/MS) was applied for the characterization of the lacquer resulting that it is based on urushi. The possibility to classify the drying oil (tung or linseed oil) present in the lacquer is highlighted and discussed in this paper. Py-GC/MS with in-situ hydrolysis and methylation reagent tetramethylammonium hydroxide (TMAH) were performed on reference materials of linseed oil and tung oil as well as on the lacquer object samples. The results show that it is possible to unambiguously identify the drying oil, in our case, linseed oil was identified to retard the rate of hardening.  相似文献   
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