首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1288篇
  免费   396篇
  2021年   26篇
  2020年   22篇
  2019年   140篇
  2018年   110篇
  2017年   99篇
  2016年   118篇
  2015年   115篇
  2014年   108篇
  2013年   232篇
  2012年   124篇
  2011年   113篇
  2010年   85篇
  2009年   39篇
  2008年   68篇
  2007年   64篇
  2006年   39篇
  2005年   36篇
  2004年   31篇
  2003年   31篇
  2002年   22篇
  2001年   24篇
  2000年   22篇
  1999年   4篇
  1998年   5篇
  1997年   2篇
  1996年   1篇
  1995年   1篇
  1993年   1篇
  1992年   2篇
排序方式: 共有1684条查询结果,搜索用时 109 毫秒
991.
Since the late 1980s urban consolidation has become the dominant strategic planning paradigm across Australian cities; however, sites of densification are increasingly becoming sites of community resistance and conflict. In the context of the Sydney Metropolitan Strategy, this paper explores Ku‐ring‐gai in Sydney's northern suburbs as a site of community resistance centred on opposition to urban consolidation. Moving beyond more traditional constructions of community resistance as a form of NIMBYism, we present here a typology of community resistance groups and explore the complex relationships between these groups, which are used to challenge development. In addition we draw on understanding of urban publics to explore the ways in which these groups attempt to engage and act on behalf of a diverse set of publics operating across scales.  相似文献   
992.
The study of developmental abnormalities of the tarsal bones in a Portuguese Late Neolithic population was performed, as part of an ongoing research project that includes the evaluation of foot defects in Portuguese skeletal populations from Neolithic times to modern 20th century samples. Two accessory bones were found, calcaneum secundarium and os trigonum, and three non‐osseous coalitions were detected, calcaneonavicular, cuboid‐navicular and third metatarsal‐third cuneiform. The newly presented frequencies corresponded to other published sources, except for the frequency of calcaneum secundarium, higher than in previous studies (8.6% left bones; 15.2% right bones). This result suggests population homogeneity maybe due to geographic isolation and/or marriage customs although the exact pattern of inheritance of the majority of these foot anomalies is unknown. No apparent sex bias was detected and side could not be tested since these human remains were uncovered from a commingled funerary context. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
993.
Selective mortality can occur towards individuals who survive episodes of physiological stress, such as disease and malnutrition, during development. The skeletal elements affected depend on the timing of these stressful episodes. Studying multiple non‐specific indicators of stress can show which periods of development were affected and whether certain periods can be linked with selective mortality. To examine this method a preliminary study of 61 adult individuals from the Medieval population of Fishergate House, York was undertaken to examine small vertebral neural canal size and reduced adult stature. Previous studies have shown that selective mortality occurs towards individuals who display these non‐specific indicators of stress. Statistical analysis showed that small transverse neural canal diameter was significantly associated with early adult mortality for males and females and there was evidence of selective mortality towards females with reduced stature. This suggests that individuals who died in early adulthood experienced health insults during late childhood which stunted VNC growth but males in particular were not significantly affected by health insults after this age as they achieved a normal adult stature. Therefore it appears that health insults which occurred during late childhood had a greater influence on adult health in the Fishergate House population. This method could be expanded to provide more detailed information by using a greater variety of non‐specific indicators of stress which will allow more specific periods of development to be investigated. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
994.
A total of 11 340 Cartesian coordinates of 42 homologous landmarks on five excavated human crania were recorded by three observers using a three‐dimensional (3D) digitiser and computer models created with a 3D laser scanner. The aim was to compare the errors of the coordinate data of landmarks of different types recorded with these two techniques. The results showed that digitiser‐based and 3D model‐based coordinate measurements had overall standard deviations of, respectively, ±0.79 and ±1.05 mm. However, the 3D digitiser yielded the most precise coordinate data for landmarks defined primarily by biological criteria (Type I landmarks), while the 3D laser scanner models yielded the most precise coordinate data for landmarks defined primarily by geometric criteria (Type III landmarks). These findings are likely to influence the research design of future craniometric studies, as they indicate that the suitability of certain landmark types as reference points for geometric operations, such as partial Procrustes analysis, depends on the method by which they are measured. This information is particularly important for retrospective research or for combined databases such as FORDISC or CRANID, which may integrate different types of landmarks recorded by different researchers and/or instruments. Crania displaying poor preservation and surface discoloration yielded larger measurement errors, especially for the 3D model measurements. This is not surprising given that landmarks on 3D models cannot be located using tactile means, but have to be located solely on a visual basis. Nonetheless, even though the digitiser measurements exhibit an overall precision slightly greater than the 3D model measurements, both techniques yield coordinate data with a precision sufficient for most craniometric research. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
995.
Ochres were the most common source materials for pigments used in Palaeolithic rock art paintings. This work analyses the petrographic and geochemical signatures of different ochre samples from outcrops inside Tito Bustillo Cave and the Monte Castillo Caves using the most common techniques (petrography, XRD, SEM–EDS and ICP–MS) in archaeological pigment characterization studies. The results obtained permit the identification and characterization of the different source ochre types and, furthermore, allow the establishment of mineralogical and geochemical proxies for the study of questions related to ochre characterization, formation processes and provenance.  相似文献   
996.
The Pichvnari necropolis on the Black Sea coast of Georgia lies in an area known in the late first millennium as ‘Colchis’, on part of the trade route leading to the Orient. The burials of the necropolis date to the late fifth century bc and frequently contain grave goods, including extremely well‐preserved polychrome glass beads and core‐formed vessels. This paper presents a study of these vessels both stylistically and archaeologically and using SEM–WDS and LA–ICPMS. It reveals that the vessels have compositional differences that may point to multiple manufacturing sites. One of the vessels appears stylistically unique and may exhibit one of the earliest uses of manganese as a decolorizer. Major and minor element data for the vessels suggest that they may belong to the same ‘Levantine’ group as many Roman glass objects, suggesting that a source of sand on the coast of the Levant could have been used in their production. The beads clearly show glass with both natron‐ and plant ash‐based flux with distinct rare earth compositions, showing multiple sites of production, some of which were probably either in the Middle East or the Indian subcontinent.  相似文献   
997.
This paper is concerned with the manufacture and trade of post‐medieval crucibles (14th–19th centuries). The analytical study of crucibles from different contexts in Europe and America employed optical microscopy and SEM–EDS, coupled with archaeological and historical data. We identified two major producers of crucibles, both of them in Central Europe, whose products appear widely distributed internationally. The analytical data allow an explanation of the technical reasons behind their superior reputation, as both crucible types shared comparable material properties, such as thermal, chemical and mechanical stability. Conversely, the two crucible types were radically different in their manufacture and appearance. We argue that, besides technical considerations, sensorial aspects such as texture and colour may have played an important role in the perception and choice of materials.  相似文献   
998.
The Edera Cave, near Aurisina in the Trieste Karst, retains a stratigraphy that extends from the Mesolithic to the modern era. At Sauveterrian layers, many specimens of Helix cincta are present, which are considerably crushed, and a small percentage of which are also blackened. Chemical analyses show that the blackened specimens were exposed to a temperature of between 500 and 550°C, and suggest that many others were destroyed by fire at temperatures of above 700°C. Consequently, only a part of the Helix cincta shells is assumed to be the residue of human meals, since several factors render plausible an accidental combustion of shells already present in the ground before the lighting of Mesolithic hearths.  相似文献   
999.
X‐ray fluorescence and laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) analyses conducted on 40 obsidian samples from the Late Chalcolithic 2 levels at Tell Hamoukar and Tell Brak in north‐east Syria have shown trends towards the exploitation of obsidian sources in the eastern Taurus. While the Bingöl region appears to provide the majority of obsidian to both sites, there is also evidence of more minor exploitation of a source in the Lake Van area and an altogether unknown source (X). This paper presents the data acquired from the analyses of the archaeological obsidian and situates these results within their chronological and regional contexts.  相似文献   
1000.
A group of Copper Age shaft‐hole axes from Caput Adriae (northeastern Italy, western Slovenia and northwestern Croatia) manufactured using meta‐dolerite have been analysed for major and trace elements. All the samples show magmatic textures and well recognizable relicts of primary mineralogical phases. Petrographic observations suggest an ophiolitic provenance of the protolithic source(s) while geochemical data indicate that the original magmas originated in a fore arc or pre arc tectonic setting. Strong similarity has been found with several lithotypes from the Banija Ophiolite Complex (Croatia), here indicated as the most probable source area. Considering the available archaeometric data about shaft‐hole axes found in northern Italy and Caput Adriae in comparison to those of axe blades discovered in the same area, it emerges that there is a utilization of different rock types, the source of which appears to be quite close to the discovery sites. In the investigated area the shaft‐hole axes are largely made from ophiolitic‐related rocks which are associated with copper deposits. Consequently there may have been a relation between the localization of the geological sources of shaft‐hole axes and the development of metallurgical activities.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号