全文获取类型
收费全文 | 686篇 |
免费 | 64篇 |
专业分类
750篇 |
出版年
2024年 | 2篇 |
2023年 | 20篇 |
2022年 | 5篇 |
2021年 | 7篇 |
2020年 | 38篇 |
2019年 | 31篇 |
2018年 | 95篇 |
2017年 | 84篇 |
2016年 | 75篇 |
2015年 | 45篇 |
2014年 | 57篇 |
2013年 | 145篇 |
2012年 | 25篇 |
2011年 | 25篇 |
2010年 | 20篇 |
2009年 | 6篇 |
2008年 | 19篇 |
2007年 | 8篇 |
2006年 | 5篇 |
2005年 | 4篇 |
2004年 | 8篇 |
2002年 | 1篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有750条查询结果,搜索用时 15 毫秒
51.
Jesús M. González Pérez 《European Planning Studies》2007,15(1):29-50
This work analyses the main Spanish legislative and urban planning instruments, highlighting some of the most important structural problems of the current Spanish urban realities. The survey on legislation runs from the first Land Use Act of 1956 to the decentralization of the administration and the culmination of the transfer processes to the respective Spanish regions. Later, we study the complete well-structured hierarchy of urban planning instruments in use at present. Finally, we analyse how these and other factors have an influence on the capacity to control housing prices and on a lack of sustainability characterized by the excessive urbanizing use of the land. 相似文献
52.
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
53.
Bernadett Bajnóczi Gabriella Schöll-Barna Nándor Kalicz Zsuzsanna Siklósi George H. Hourmouziadis Fotis Ifantidis Aikaterini Kyparissi-Apostolika Maria Pappa Rena Veropoulidou Christina Ziota 《Journal of archaeological science》2013,40(2):874-882
Determination of the source of Spondylus objects is essential for the interpretation of Late Neolithic exchange systems and the social role of shell ornaments. We performed stable isotope analysis combined with cathodoluminescence microscopy study on ornaments (beads, bracelets) made of Spondylus shells excavated at the Aszód-Papi földek archaeological site in Hungary, to define their origin. For comparison Spondylus finds from Neolithic sites of Greece, modern Spondylus shells from the Aegean and the Adriatic, as well as fossil Spondylus and Ostrea shells from the Carpathian Basin were also examined. Oxygen isotope composition of Spondylus finds from Aszód ranges between ?1.9 and 2.1‰ and overlaps with the oxygen isotope range of shell objects from other Neolithic sites. Modern Spondylus shells from the Aegean and the Adriatic show overlapping δ18O values with one another and with the Neolithic objects; while recent shells of the Black Sea clearly are separate isotopically from the Mediterranean ones and most of archaeological artefacts. Spondylus shells from the Aszód site have Mediterranean origin; their source can be the Aegean or the Adriatic. Based on a former strontium isotope study the use of fossil Spondylus shells is excluded as raw material used for ornaments, however, in recent years the use of fossil shells was reintroduced. The shell ornaments from Aszód-Papi földek and the fossil oyster shells collected from the Carpathian Basin exhibit some overlapping oxygen isotope values; however, cathodoluminescence microscopy indicates that the Spondylus objects retained their original aragonite material. Diagenetic calcite, which occurs typically in the fossil shells, was not detected in the ornaments suggesting that the studied objects were made of recent shells. Calcitic parts observed in some Spondylus objects are not related to fossilisation. 相似文献
54.
G. Huelga‐Suarez M. Moldovan M. Suárez Fernández M. Ángel de Blas Cortina J. I. García Alonso 《Archaeometry》2014,56(4):651-664
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
55.
Alexandr Chvátal 《Journal of the history of the neurosciences》2014,23(4):367-376
Ji?í (George) Procháska (1749–1820), a Czech anatomist, physiologist, and neuroscientist of the eighteenth century, ranks among the major figures of Czech and European cultural history. The works of Ji?í Procháska, due to historical circumstances, were published mostly in Latin and only some in German. However, given that only one treatise was partially translated into English, the results of his extensive research activities are currently unavailable to the international scientific community. The achievements of Ji?í Procháska undoubtedly belong to the major intellectual heritage of European science and certainly deserve attention as such, although his research reflected the time in which he lived and therefore has been reevaluated by later researchers. Undoubtedly, it is our duty not only to remember the work and legacy of Ji?í Procháska, which significantly influenced the development of our knowledge, but also to try to critically assess his contribution in terms of today. This article surveys the important biographical events of Ji?í Procháska’s life, taking into account the significance of his research. 相似文献
56.
57.
Olga Löblová 《政策研究杂志》2018,46(1):160-189
Epistemic communities are an established concept in the study of international relations but can also explain policy change at the domestic level. This article asks why some epistemic communities manage to convince decision makers of their preferred policies while others do not. It suggests that the reason lies in the causal mechanism of epistemic communities' influence on decision makers, mediated by decision makers' demand for expert input. Most epistemic communities scholarship focuses on single case studies where the communities' influence on policy was strong and clear, leading to an overestimation of the groups' influence. To help correct this probable bias, this article compares a successful case of epistemic community influence (health technology assessment in Poland) with an unsuccessful example of the same policy (in the Czech Republic). The juxtaposition allows for unpacking of the necessary parts of the causal mechanism (emergence of an epistemic community, its activity, access to decision makers, and successful suasion) and separating them from the crucial scope condition. Decision makers' uncertainty about the policy issue at hand has traditionally been the key scope condition for epistemic communities but the successful Polish case demonstrates that epistemic communities can be influential even in highly certain areas of routine policymaking, leading to a reconceptualization of uncertainty as policymakers' demand for expert input. Demand can originate from various sources, but any change of it affects individual parts of the causal mechanism, leading to a success or failure of epistemic communities' policy enterprise. 相似文献
58.
59.
60.
THE EFFECT OF ACCESSIBILITY ON PRODUCTIVITY IN SPANISH MANUFACTURING FIRMS 总被引:1,自引:0,他引:1 下载免费PDF全文
David Martín‐Barroso Juan A. Núñez‐Serrano Francisco J. Velázquez 《Journal of regional science》2015,55(5):708-735
This paper evaluates the impact of accessibility on the productivity of Spanish manufacturing firms. We suggest the use of accessibility indicators of workers and commodities, integrating transport, land use, and individual components, computing real distances or traveling times using the Spanish full road network. Estimated firms’ total factor productivity is explained as a function of the accessibility indicators and additional control variables. Results evidence the crucial role on firms’ productivity to the accessibility of commodities and to a slightly lesser extent the workers. 相似文献