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   838篇
  免费   59篇
  897篇
  2024年   2篇
  2023年   26篇
  2022年   3篇
  2021年   11篇
  2020年   41篇
  2019年   50篇
  2018年   111篇
  2017年   83篇
  2016年   76篇
  2015年   53篇
  2014年   48篇
  2013年   163篇
  2012年   44篇
  2011年   32篇
  2010年   26篇
  2009年   25篇
  2008年   18篇
  2007年   12篇
  2006年   5篇
  2005年   11篇
  2004年   4篇
  2003年   3篇
  2002年   8篇
  2001年   13篇
  2000年   2篇
  1999年   2篇
  1998年   1篇
  1997年   4篇
  1996年   2篇
  1995年   9篇
  1994年   2篇
  1993年   2篇
  1992年   3篇
  1982年   1篇
  1979年   1篇
排序方式: 共有897条查询结果,搜索用时 15 毫秒
61.
62.
This paper records a conversation that took place on Thursday 23rd November 2006 at the Museo del Hombre de Antofagasta de la Sierra (Museum of Man of Antofagasta de la Sierra), Catamarca, Argentina. The conversation involved different research groups co-investigating, each formed by a student of archaeology and a member of the personnel of the museum and/or other areas of the culture of the municipality of Antofagasta de la Sierra. Each presented the state of his/her enquiry into a particular object in the museum collection. The task was to tie stories to objects: stories by the elders of the town, the people who had discovered the item, the personnel of the museum and the texts written by archaeologists. This paper focuses on the conversation with Ernestina Mamaní, about a stone slab by Antofagasta elder, Don Anacleto Cháves, which she and Laura Roda had chosen to research.
Résumé Cet article rapporte une conversation qui a eu lieu le jeudi 23 novembre 2006 au Museo del Hombre de Antofagasta de la Sierra (Musée de l'homme d'Antofagasta de la Sierra), Catamarca, Argentine. La conversation mettait en scène différents groupes de recherche travaillant conjointement, chacun constitué d’un étudiant en archéologie, d’un membre du personnel du musée et/ou d'autres secteurs du service de la Culture de la municipalité d'Antofagasta de la Sierra. Chacun a présenté l'état de ses recherches autour d’un objet particulier des collections de musée. Il s’agissait d’accoler des récits aux objets: histoires rapportées par les anciens du village, les personnes ayant découvert l'objet, le personnel du musée et les rapports écrits par les archéologues. Cet article relate particulièrement la conversation avec Ernestina Mamaní, au sujet d'une dalle de pierre faite par un ancien d'Antofagasta, Don Anacleto Cháves, qu’elle même et Laura Roda avaient choisie pour leur recherche.

Resumen Esta ponencia registra una conversación que sucedió el jueves 23 de noviembre de 2006 en el Museo del Hombre de Antofagasta de la Sierra, Catamarca, Argentina. La conversación involucraba diferentes grupos de co-investigación, integrado por una estudiante de arqueología y un miembro del personal del museo y/o otras areas de cultura de la municipalidad de Antofagasta de la Sierra. Cada una presentaba el estado de su indagación acerca de un objeto particular de la colección del museo. La consigna era anudar historias a cada objeto, historias ofrecidas por los ancianos del pueblo, los descubridores de la pieza, el personal del museo y los textos escritos por arqueólogos. Esta ponencia se focaliza en la conversación con Ernestina Mamaní, sobre una laja encontrada por un vecino de Antofagasta, Don Anacleto Cháves, que ella y Laura Roda habían elegido para investigar.
  相似文献   
63.
The paper deals with dendrochronological and radiocarbon dating of subfossil trunks found in the basin of the Morava River. The research into subfossil trunks had been conducted in the Czech Republic in the past but the research stopped in 2001. 160 records of measurements of subfossil, predominantly oak trunk samples, are preserved from that time. Three years ago the research was reopened and again the most trunks were found in the basin of the Morava River. 92 samples of oak trunks and 7 samples of other tree species (poplar, elm, maple, beech) were taken from selected sites. The samples were processed in compliance with the standard dendrochronological methodology. To date the samples, Czech, Austrian, Polish and German standard chronologies were used. In cases when the dendrochronological dating was unsuccessful, the samples were sent for radiocarbon dating. In total, 35 samples were dated, mainly by the radiocarbon method. Subfossil trunks from gravel pit Tovačov were dated and classified into 4 different periods, the oldest being from 2780–2190 BC. In Osek nad Bečvou, the samples were taken from two sites. Whereas from the 4 trunks taken in the river channel each was from a different period, the trunks from the gravel pit come from 981–1015 AD. The trunks found in the Morava River basin near Strážnice were dated to the 10th–15th century. In the future, we expect to extend the amount of the acquired samples with the aim to create a link to the existing standard chronology or to create a long floating average treering curve.  相似文献   
64.
This paper presents, for the first time, a detailed study, from an archaeological perspective, of the morphological characteristics of the starch grains within the kernels of selected native wild grasses found in the Central Pampas of Argentina. We compared native wild grasses to maize starch grains, which can be distinguished from each other based on their size, shape and other attributes. The majority of the studied grains did not share morphological characteristics with maize starch grains. Considering this, it can be said that, if irregular and polyhedral grains with transverse or radial fissures dominate the starch assemblage, maize identification may be done on the basis of both morphology and size. Additionally, this research contributes to the characterization of the starch grains of the Panicoideae subfamily, which includes maize. Several classes of simple and compound starch grains are described and defined for native species of Pooideae, Chloridoideae, Arundinoideae, and Panicoideae subfamilies. The results obtained may constitute a baseline for the future determination of maize and wild grass use in archaeological contexts belonging to Middle/Late Holocene hunter–gatherers in the Pampas of Argentina and neighboring areas.  相似文献   
65.
This paper continues the characterization of the lead isotopic fingerprint of ancient copper mines in the north‐west of Spain. In this work, the lead isotopic compositions found in copper ores from the La Profunda mine are presented. Azurites and malachites sampled from this deposit were subjected to lead isotope analysis by multicollector ICP–MS. The results showed a clear radiogenic lead signature compatible with the presence of uranium‐rich minerals (such as zeunerite) in the same mining complex. Moreover, a rare copper artefact, found in the galleries of the mine during its modern exploitation, was also analysed and showed that local mineral was used for its manufacturing.  相似文献   
66.
Relying on stochastic frontier analysis we propose a methodology to study the technological characteristics and cost efficiency levels related to the provision of public infrastructure for basic utilities. The methodology assumes a cost minimizing behaviour on the part of public officials when planning the construction of local infrastructure, which is represented by way of a flexible translog cost function. Introducing relevant definitions of scale economies, associated with larger numbers of inhabitants and dwellings, as well as economies of density, brought about by reductions in urban dispersion, we analytically determine the optimal population densities for which average cost is minimized. We illustrate our model with the water cycle sector, including water distribution, sewage collection and cleansing of wastewater, and considering data at the municipality level for the Spanish region of Castilla y León. The obtained results indicate potential cost savings in the form of decreasing average costs, as relevant scale and density economies are present, along with large inefficiency levels. Relevant policy guidelines favouring larger and denser urban sizes are drawn, as the observed cost excess is the result of a general suboptimal urban size in terms of population density, and the negative effects of dispersed settlement patterns.  相似文献   
67.
City districts are often classified as ‘rich’ or ‘poor,’ a phenomenon that occurs within cities all over the world. While income inequality, wealth inequality, and other kinds of social inequality are frequently tracked, there is a surprising lack of research concentrating on how social inequality manifests as differences between parts of cities, especially outside of the U.S. That is mostly due to insufficient available data. In this paper, we propose a methodology for measuring the relative inequality between city districts by using the average prices of residential properties in various parts of the city, and assessing their relative difference. This approach has several advantages, as property listings are often readily available even in cities where income data is not. This methodology has potential for measuring developments in inequality in a much wider range of cities. As a proof of concept, we apply this methodology to property prices in Prague during the period 2003–2012 to identify a trend of either growing or decreasing inequality among individual parts of the city. We have found that during this period the disparity has grown only 5.97%, which means the overall growth of disparity between the city districts was negligible.  相似文献   
68.
Despite the large-scale expansion of Bell Beaker phenomenon, there is a tension between the normative Bell Beaker material culture categories and their local objectification in the form of real artefacts. Stone projectile points provide an opportunity to evaluate how much was the general category of such a point influenced by regional and local factors. The aim of this paper is to explore shape and size variation of Central European Bell Beaker projectile points from Moravia (Czech Republic) to elucidate factors responsible for this variation. The sample consists of 194 projectile points from 54 Central European Bell Beaker sites (2500–2300/2200 BC) distributed in Morava River catchment. The size and shape of projectile points were studied by landmark-based geometric morphometrics and expressed as shape groups, which have been assessed in terms of their spatial distribution, raw material, and reutilization. Although several shape categories of points were identified, there is a strong degree of uniformity in the research sample. The dominant shape category (75.4 % of points) was pervasive across geographic space and was not significantly affected either by raw material or reutilization. A lower degree of reutilization of points is interpreted as a consequence of a non-utilitarian role of projectile points, which represented a critical component of Bell Beaker mortuary practices.  相似文献   
69.
The aim of this work is to characterize the original concrete from Roman buildings for public spectacles, theatre and amphitheatre, from Emerita Augusta, Mérida, Spain. An advanced knowledge of the Roman concrete composition is required for a reliable restoration and preservation of these ancient monuments. The concrete was studied through mineralogical (optical polarized microscopy and X-ray diffraction) and petrophysical (bulk and real density, open porosity to water and Hg, mechanical strength and ultrasonic velocity) analyses. With this work, it is possible to fill the gap that exists in this field and the characterization of the materials used in the Roman concrete from these two buildings, never previously studied, despite the significance of this archaeological ensemble, declared a World Heritage Site by UNESCO in 1993. The results allowed us to determine the composition of the Roman concrete and to infer the provenance of the aggregates used in these monuments.  相似文献   
70.
ABSTRACT

The “Quartel das Esquadras” is an 18th century infantry barrack located within the limits of the bulwarked fortress of Almeida, in Portugal. An ongoing adaptive reuse project of the building aims to recover its full capacity and also its importance, by implementing a variety of new uses. The architectural intervention results in the need of the structure to withstand new and diverse imposed loads. As the current configuration of the structure will be altered, the main objective of this article is to evaluate the suitability of some of the proposed structural interventions. The current condition has been characterized following a multidisciplinary approach comprising historical research, visual inspection, non-destructive testing, and structural analysis to identify the possible sources of major structural problems. A portion of the building particularly affected by the alterations has been selected to carry out structural analysis. A comparative safety assessment of the selected area in both current and altered condition has been done through finite element modelling and nonlinear static analysis, resulting in an identification of the weaker points against the new implemented loads and alterations. Finally, proposals for the implementation of the studied intervention, as well as recommendations for future research and analyses, have been given.  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