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71.
可溶盐是石质文物风化的重要原因,其聚集、运移与水密不可分。石窟顶部土层中的盐是云冈石质文物内部盐分的重要来源,因而研究石窟顶部土层中的水盐分布特征对未来减小可溶盐在石质文物内部的聚集具有十分重要的意义。本研究对云冈石窟顶部不同位置、不同深度土层的饱和渗透系数、含水率、孔隙比、可溶盐含量进行了系统的分析测试,并结合取土位置的坡度和植被覆盖率,研究了云冈石窟顶部土层中水盐分布特征。结果表明:植被覆盖率越高,土体含水量越高;坡度越大,土体含水率越低;土体孔隙比与饱和渗透系数呈线性关系。植被覆盖率、坡度及土体的渗透性能是影响石窟顶部土层水盐分布的主要原因。  相似文献   
72.
High precision lead isotope analysis by Multi Collector Inductively Coupled Plasma Mass Spectrometry was applied to the investigation of more than 240 Roman lead objects from several archaeological sites in Germany, in order to obtain information on the pattern of Roman mining activity and ore processing in the area. Measurements of ore samples from German deposits east (Siegerland, Lahn-Dill, Ems) and west of the Rhine (Eifel, Hunsrueck) were made and supplemented with data from literature to create a data bank of lead isotope ratios of European lead occurrences. Comparing the isotope ratios of lead objects with those from German ore deposits shows that the source of over 85% of the objects is Eifel ore deposits, but that, in the early years, the Romans also imported lead from the Southern Massif Central and later from Britain.  相似文献   
73.
For nearly four hundred years, Pueblo potters in the Rio Grande Valley of New Mexico produced technologically innovative glaze-decorated bowls and exchanged them widely among different villages. While potential sources of lead ores used to make glaze paints are found throughout the Rio Grande Valley region, researchers have only recently begun to identify which ore sources potters exploited and to understand the social and economic factors underlying patterns of ore resource use. In this paper we use stable lead isotope and electron microprobe analysis of glaze paints on Rio Grande Glaze Ware made at two Salinas pueblos to identify ore sources and glaze recipes used by their potters. Despite some isotopic overlap of ore sources, the lead isotope data point to regular exploitation of ores from the Socorro area of the southern Rio Grande. Salinas potters apparently used other sources as well, and likely mixed ores from different sources. We also identify four local glaze recipes that appear to incorporate multiple ore sources, suggesting that Salinas potters obtained raw ores rather than finished glaze paints.  相似文献   
74.
The glazes of seven types of greenware produced in the Yue and Longquan kilns between the Tang dynasty and the Ming dynasty (ad 618–1644) were studied for their strontium isotopic compositions and bulk chemical compositions. The aim was to identify the raw materials used as the calcium fluxes in the glaze recipes and whether the raw materials changed over time, particularly before and after the Southern Song dynasty (ad 1127–1279). From this work, botanic ash has been identified as the raw material used as the calcium flux in all the seven glaze types studied, and some related ceramic historical issues are also discussed.  相似文献   
75.
Focusing on the Swedish census of 1900, the child-woman ratio and own-children method have been applied to assess socioeconomic differences in fertility. These indirect estimates of fertility have been compared to the vital statistics at the national level to assess their reliability. This comparison demonstrated that the estimated results suffered from few errors. Even if these indirect estimates of fertility could be affected by possible socioeconomic differences in mortality, the tests show that at least in the Swedish case, the impact of mortality on the indirect measures is limited. As infant mortality differences by socioeconomic status are relatively small, indirect fertility estimates are mainly affected by differences in reproductive behavior.  相似文献   
76.
南昌西汉海昏侯墓发掘出土了数量较多的马蹄金,为汉代黄金货币的研究工作提供了宝贵资料,出土马蹄金内均存在镶嵌物,大部分腐蚀严重。结合偏光显微分析、背散射扫描电镜\能谱、红外光谱、X射线衍射光谱对海昏侯墓主棺头箱出土的部分马蹄金内嵌物进行分析研究,依据分析结果将马蹄金内嵌物分为透闪石软玉、蛋白石、铅钡玻璃和疑似高铅玻璃4种类型。其中,铅钡玻璃基本保留玻璃态,腐蚀产物随着埋藏环境的变化存在二次结晶现象,腐蚀的最终产物是碳酸铅;疑似高铅玻璃表现出完全不同的腐蚀状态,外层硅质成分较高形成较为致密的壳状结构,内部碳酸铅以葡萄状填充在少量的硅质成分中。研究结果可为后续的保护处理与马蹄金、麟趾金的复制工作提供理论支持。  相似文献   
77.
城市容积率确定的技术要点透视   总被引:7,自引:0,他引:7  
容积率是反映城市土地利用强度的一项重要指标。本文提出了利用大比例尺航空像片测定现状容积率的技术路线和方法。对于规划容积率,可通过逐层控制、地块测算和因素修正的方法,予以确定。  相似文献   
78.
龙韬  柴彦威  忻俊  马玫 《人文地理》2008,23(4):17-22
在城市化的过程中,随着大城市空间的扩张,出现了一种与传统的外延型城市化完全不同的新型城市化地区。这些新型城市化地区的出现显著改变了大城市的地域空间结构,并已成为我国城市化和城市空间扩张的重要方式。以天津经济技术开发区居民社区发展问卷调查为第一手资料,通过分析居民对这一新型城市化地区不同阶段有代表性的城市公共空间的认知状况、利用状况及其影响因素,为此类型地区的城市公共空间建设提供科学依据。  相似文献   
79.
This paper presents strontium and oxygen isotopic measurements on archaeological human teeth from the ancient Maya city of Tikal, Guatemala, that illuminate the role that migration played in the history of the state. Stable strontium isotope ratios of human teeth parallel the bedrock geology of the location where foods were grown, while stable oxygen isotope ratios reflect the sources of water imbibed, and track geographic variation in the isotopic composition of rain water. Because tooth enamel forms during childhood and is not remodeled during life, we can identify foreign-born individuals at Tikal by their outlying strontium and oxygen isotope ratios. These data indicate that approximately 11–16% of the sampled Tikal skeletons spent their childhood at distant sites. Most of the migrant burials date from the Early Classic period and are high status contexts. Several royal burials demonstrate long distance movement of both males and females, and shed light on the identification of epigraphically-known individuals. Yet, both Early and Late Classic migrants are found in lower status domestic burials. Interaction with distant peers was important in the rise of the Tikal polity, however, immigration from all social tiers contributed to the city’s rapid population growth.  相似文献   
80.
Trace element analysis related to archaeological bone is viewed as one way to determine levels of element exposure in past populations. This area of research is complex because there is the potential for the incorporation of trace elements from the burial environment into archaeological bone. We tested the hypothesis that matching the spatial distribution of trace elements within cortical bone with the biological structures would provide evidence of biogenic uptake. We examined samples from a non-segregated Royal British Naval cemetery (1793–1822) in Antigua, West Indies. A key historical question related to this population was the extent of exposure to lead and the resulting health effects. Images from conventional light microscopy (histological) analysis of the bone samples were matched with elemental maps of calcium, strontium, and lead that were created through the use of synchrotron radiation X-ray fluorescence (SR-XRF). Biogenic uptake of both strontium and lead was indicated based on the localization of these trace elements within discreet microstructural elements. The successful integration of histological information with XRF data is a powerful technique for the interpretation of past biological events through trace elements.  相似文献   
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