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   799篇
  免费   43篇
  2023年   7篇
  2022年   4篇
  2021年   7篇
  2020年   13篇
  2019年   25篇
  2018年   38篇
  2017年   46篇
  2016年   44篇
  2015年   36篇
  2014年   30篇
  2013年   145篇
  2012年   26篇
  2011年   36篇
  2010年   21篇
  2009年   32篇
  2008年   29篇
  2007年   15篇
  2006年   10篇
  2005年   12篇
  2004年   15篇
  2003年   9篇
  2002年   9篇
  2001年   11篇
  2000年   13篇
  1999年   8篇
  1998年   6篇
  1997年   13篇
  1996年   9篇
  1995年   12篇
  1993年   10篇
  1992年   10篇
  1991年   5篇
  1990年   7篇
  1989年   4篇
  1988年   5篇
  1986年   5篇
  1985年   4篇
  1984年   4篇
  1983年   4篇
  1980年   6篇
  1977年   11篇
  1976年   6篇
  1975年   4篇
  1972年   5篇
  1971年   4篇
  1969年   5篇
  1967年   4篇
  1966年   4篇
  1965年   4篇
  1959年   4篇
排序方式: 共有842条查询结果,搜索用时 15 毫秒
71.
Field courses are essential for subjects like Earth Sciences, Geography and Ecology. In these topics, GIS is used to manage and analyse spatial data, and offers quantitative methods that are beneficial for fieldwork. This paper presents changes made to a first-year Earth Sciences field course in the French Alps, where new GIS methods were introduced. Students use GIS in preparation to explore their research area using an elevation model and satellite images, formulate hypotheses and plan the fieldwork. During the fieldwork, a pilot group managed their field-observations using GIS and made digital maps. Students praise the use of quantitative digital maps in the preparation. Students made use of the available techniques during the fieldwork, although this could be further intensified. Some students were extra motivated due to the technical nature as well as the additional analytical possibilities. The use of GIS was experienced as a steep learning curve by students, and not all staff members are confident in supervising students using GIS, which calls for a sufficient preparation and training of both students and staff. The use of GIS adds abstract analyses and quantitative assessment, which is a complementary learning style to fieldwork that mostly focuses on practical skills.  相似文献   
72.
73.
The nature of British rule in Palestine, as it settled down after the approval of the Mandate in 1922, had its critics among the Zionist ranks. Using original sources, this paper examines the attitudes of the leadership of the Revisionist Union (RU) towards the British from the first quarter of the 1920s till the mid-1930s. Unlike the later paramilitary organizations, the Revisionist founders, convinced, in their own words, of the common interests shared with the British Empire, had no intention of terminating the British presence, but sought to transform it in order to serve Zionism’s objectives. While official Zionism preferred backstage diplomacy, the RU pursued a different strategy – appealing directly to the masses and making its cause as public and vocal as possible. Eventually, the RU’s strategy combined the principle of pro-British orientation with merciless criticism of Palestine policies on the ground. As far as the British were concerned, the Colonial Office was at best willing to tolerate a set of proposals they saw as unrealistic. Once these started to actively erode the integrity of British policy in the region, unsolicited “enthusiasm” was reclassified as dangerous “extremism.”  相似文献   
74.
This paper investigates the interplay between cultural traditions and policy effectiveness. It explores the differential impact of a large development program (Cassa per il Mezzogiorno), implemented for four decades, starting in the 1950s, to stimulate convergence between Italy's south and the more developed north, on municipalities with different histories. Namely, we consider a sample of municipalities located on either side of the historical border of the Kingdom of the Two Sicilies, whose legacy is considered, from Putnam onwards, to be a prime‐facie cause of Southern Italy's underdevelopment. Having been part of the Kingdom of the Two Sicilies is associated with a negative impact of development policies, but only when the allocation of development funds through the Cassa per il Mezzogiorno suffered from low quality of governance and was driven by political considerations rather than by efficiency ones.  相似文献   
75.
This paper measures the impact of wage zones—compulsory wage differentials at the province level—on Italy's local labor markets during the 1950s. Using spatial regression techniques, it finds that for the industrial sectors covered under wage zones there was an increase in employment when one crossed the border from a high‐wage province into a low‐wage one; the effect diminished, however, as the distance from the boundary increased. The paper also illustrates that the impact on the overall (nonfarm) private sector, which includes both covered and uncovered sectors, was negligible.  相似文献   
76.
Grasslands pose a particular problem for archaeological survey involving artifact assessment, as no material is plowed up to the surface. Although finds in molehills are often the only source of information available on sites with such low visibility, an archaeology of molehills has thus far been largely disregarded. Yet, by applying a low-cost and time-efficient methodology, both the potential and the pitfalls of molehill archaeology come to the forefront. At the medieval harbor site of Monnikerede, it was possible to assess material culture and to locate certain structural elements. However, when artifact densities were compared with the underlying geophysical anomalies, a more complex relationship appeared at the level of individual features.  相似文献   
77.
We present experimental data examining the energetics and identification of axial bipolar reduction in contexts of lithic miniaturization on milky quartz. These experiments answer two specific questions. First, does bipolar reduction provide any benefits over freehand reduction? Second, can axial bipolar reduction be distinguished from freehand reduction? Our data show that bipolar reduction requires significantly less time to reduce a percentage unit of core mass and to produce a millimeter of cutting edge on milky quartz than freehand reduction. Milky quartz bipolar reduction surpasses even the cutting edge production efficiency of obsidian pressure blades. We outline a series of quantitative criteria for identifying bipolar cores and flakes. Our results show that bipolar cores and flakes can be distinguished from those produced using freehand reduction by quantifying platform crushing, distal flake rebound scars, bulb shearing, as well as axial, bipolar, and splintered flake terminations. Our results challenge the widely held perceptions about the wastefulness of bipolar reduction and provide clear guidelines for identifying this reduction strategy in archaeological milky quartz assemblages.  相似文献   
78.
Drawing on several rounds of nationally representative household survey data for Indonesia, this article shows that poverty rates among the elderly are substantially higher than those of the rest of the population. Using sensitivity checks on adult equivalence scales and economies of scale, the author demonstrates that the gap in poverty rates between the elderly and non‐elderly population would increase even further if moderate changes to the per‐consumption expenditure assumption were made. Additional panel data evidence reveals that about one‐third of the elderly population is currently vulnerable to poverty. While the findings do not show gender differences in old‐age poverty rates, they do highlight important differences in living arrangements across gender, with the majority of elderly women being widows while the majority of men are still married at all ages.  相似文献   
79.
This article analyses a collection of 26 watercolour drawings which portray ethnographic types from the Americas, Asia, and Africa. These drawings, presently kept at the British Library, were made for John Locke by his servant Sylvester Brounower during Locke’s exile in the Netherlands in the 1680s.  相似文献   
80.
This paper reports on the construction of a full‐scale Bronze Age‐type sewn‐plank boat based on the Ferriby boats. The boat, which was named Morgawr, was constructed in the National Maritime Museum Cornwall in Falmouth, England, during 2012 and the first months of 2013, as part of a larger exhibition in the museum. This paper provides the background and context of the project, describes the process of building the craft, and reflects in particular on differences between Morgawr and the ‘hypothetical reconstruction of a complete sewn‐plank boat’ published in 1990 by Ted Wright and John Coates which formed the basis for this project.  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