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   1446篇
  免费   66篇
  2023年   8篇
  2020年   14篇
  2019年   25篇
  2018年   44篇
  2017年   30篇
  2016年   44篇
  2015年   35篇
  2014年   35篇
  2013年   459篇
  2012年   64篇
  2011年   59篇
  2010年   53篇
  2009年   57篇
  2008年   27篇
  2007年   47篇
  2006年   55篇
  2005年   18篇
  2004年   24篇
  2003年   22篇
  2002年   20篇
  2001年   25篇
  2000年   18篇
  1999年   11篇
  1998年   15篇
  1997年   8篇
  1996年   13篇
  1995年   16篇
  1994年   12篇
  1993年   12篇
  1992年   10篇
  1989年   11篇
  1988年   9篇
  1987年   7篇
  1986年   8篇
  1985年   9篇
  1984年   9篇
  1983年   13篇
  1982年   8篇
  1981年   8篇
  1980年   14篇
  1979年   12篇
  1978年   9篇
  1977年   7篇
  1976年   7篇
  1974年   12篇
  1972年   6篇
  1971年   8篇
  1968年   10篇
  1967年   6篇
  1966年   7篇
排序方式: 共有1512条查询结果,搜索用时 15 毫秒
41.
42.
43.
Fifty-one waster sherds of Terra Sigillata (~20-0 b.c. ) from Arezzo, Italy and Lyons, France have been chemically analysed for twenty-eight elements by neutron activation and seven by X-ray fluorescence. Most of the elemental abundances were measured with high precision and cross-comparisons of the two techniques of measurement (and sample preparation) give added insight as to their relative precision, the calibration differences and the extent to which volatile materials such as carbonate or water influence the results. The sherds from Arezzo formed a homogeneous and distinctive chemical group while all but two of those from Lyons were classified into three such groups. Two of the Lyons groups (MML A and MML B) were from Montée de La Muette and one was from Loyasse. Four additional sherds from houses excavated in Strasbourg and one from Lyons, all of which bore the signature of the famous Anetine pottery-making firm of Ateius, were also analyzed by the same techniques. These signed sherds all had the same composition pattern and it closely matched one of those from Montée de La Muette (MML A) in Lyons. It is therefore suggested that these five sherds bearing the Ateius signature were made in the general vicinity of Lyons and were part of the output of an as yet unknown Gallic branch of the firm of Ateius.  相似文献   
44.
45.
46.
The period comprising the end of the Early Neolithic and the Middle Neolithic, dated broadly within the fifth millennium cal BC, corresponds to an interval that remains largely unknown in the extreme north-western tip of Africa. This situation contrasts with that of the Early Neolithic, a period characterised by the earliest evidence of the diffusion of a productive economy, cultivated plants and domestic animals. The paucity of data for these later phases can be explained in part by the lack of secure contexts and sequences based on radiocarbon datings of short-lived samples. The current study presents the results of the excavations of El-Khil Caves B and C that yield materials allowing re-evaluation of the chronology of a type of ceramic known as Ashakar ware. The study also identifies two traditions in the northern Moroccan Middle Neolithic. The first is heir to the so-called Impressa Mediterranean ware and rooted in the Cardial Neolithic, while the second is characterised by roulette cord impressions, red slip and tunnel lugs and probably rooted in the region of the Sahara, and has no technological precedents in the study area.  相似文献   
47.
This paper studies the territorial effects of the LEADER approach in Southern Europe, by analysing the region of Andalusia (Spain). Our research has revealed that, in many cases, projects were concentrated in the most dynamic, most populated areas, with a well-established business network with the financial and organizational capacity required to access European funding. In these areas, the economic leadership of the most dynamic municipalities has been reinforced at the expense of more depressed areas with little social capital and few businesses. These programmes have not, therefore, helped to mitigate territorial imbalances. In a minority of rural areas, however, this trend was not observed, which shows that although territorial inequality is a widespread problem in the practice of neo-endogenous rural development, it does not affect all areas to the same degree.  相似文献   
48.
Most quantitative approaches to distributional analysis in archaeology assume a homogeneous study surface that is amenable to easy generalisations. This framework has been widely used to describe settlement processes, disregarding the spatial heterogeneity inherent to geographic reality. In other words, researchers have often assumed that the correlation between the elements of a spatial distribution is a function of the Euclidean distance (i.e. straight line distance) between them. Other archaeological studies have tested alternative measures to Euclidean distances, such as cost-based ones, both to describe optimal routes and to assess spatial autocorrelation in a point pattern. Nevertheless, until now there has been no suitable model to introduce these measures into spatial statistical equations. In order to overcome this obstacle, we approach the implementation problem inversely by embedding the spatial pattern under study into a Euclidean frame of reference based on its cost-distance pairwise matrix. This paper describes the application of this methodology on one of the main tools used by archaeologists to assess settlement patterns: Ripley’s K function. We present two case studies, covering both macroscale and mesoscale, with significant variations in the results depending on the use of the Euclidean or cost-based approach. Data, functions and results have been R-packaged for the sake of reproducibility and reusability, allowing other researchers to build upon our methods.  相似文献   
49.
50.
The restoration of paintings on elements in cultural heritage buildings (fundamentally, churches) involves two structural problems: capturing the geometry of the construction element and its development. In many cases, the geometries are regular (e.g., cylinders, spheres, elliptical domes). However, there are cases in which the elements cannot be adapted to any known geometry, much less one that can be mathematically developed. The development of surfaces becomes essential for the restoration of paintings over “flat elements” (over which work is performed on the ground) that are subsequently transferred to the real surface (ceilings). The mathematical transformations that allow regular geometries to be developed are widely known (cartographic projections). However, when the geometry is irregular, there is no development. This study presents a new methodology based on differential rectification and its application for the development of oculi in the Los Santos Juanes Church (Valencia), whose geometry is completely irregular both in shape and as a result of construction defects (and damage caused by fire). The present study focuses on the restoration of paintings damaged by fire.  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