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   1426篇
  免费   402篇
  2023年   1篇
  2022年   3篇
  2021年   28篇
  2020年   42篇
  2019年   146篇
  2018年   114篇
  2017年   108篇
  2016年   126篇
  2015年   117篇
  2014年   112篇
  2013年   239篇
  2012年   130篇
  2011年   122篇
  2010年   93篇
  2009年   49篇
  2008年   80篇
  2007年   68篇
  2006年   50篇
  2005年   38篇
  2004年   35篇
  2003年   38篇
  2002年   24篇
  2001年   30篇
  2000年   23篇
  1999年   5篇
  1998年   1篇
  1997年   2篇
  1995年   1篇
  1993年   1篇
  1990年   1篇
  1983年   1篇
排序方式: 共有1828条查询结果,搜索用时 15 毫秒
31.
Intensive farming is an increasing part of Australian agriculture, including in the multi‐functional landscapes at the edges of Australian cities. The example of intensive “broiler” poultry production reveals the tensions that arise when sites of hyper‐productivity conflict with social change in rural areas. Planning processes for intensive farming in the Australian state of Victoria are predicated on stability and consensus: on assumed static and uncontroversial ideas of agriculture, its place, and the primacy of agricultural productivity. Yet concerns about the industrialisation of agriculture are live political issues at the local level, especially in dynamic peri‐urban locations. This paper explores the emergence of a politics of place outside the bounds of planning consensus through an analysis of planning appeals and associated media relating to planning permits for intensive poultry developments in Victoria over 2011–2016. We highlight tensions that exist in relation to technical planning assessments and categorisations used to assert farming as the orthodox use of rural land, especially when new forms of farming look and feel demonstrably different. Using Mouffe's problematising of the negation of antagonism and Rancière's notion of the risks of a false consensus democracy, we argue that planning processes for intensive farming illustrate critical issues in participatory planning. While ostensibly post‐political decision‐making narrows the politics of place and food systems to decisions about policing the boundaries and buffer distances placed around intensive poultry developments, alternative representations of rural life persist. The certainty offered by code‐based planning does not negate the ongoing (if inconvenient) politics of intensive peri‐urban agriculture.  相似文献   
32.
Capillary trapping is a physical mechanism by which carbon dioxide (CO2) is naturally immobilized in the pore spaces of aquifer rocks during geologic carbon sequestration operations, and thus a key aspect of estimating geologic storage potential. Here, we studied capillary trapping of supercritical carbon dioxide (scCO2), and the effect of initial scCO2 saturation and flow rate on the storage/trapping potential of Berea sandstone. We performed two‐phase, scCO2‐brine displacements in two samples, each subject to four sequential drainage–imbibition core‐flooding cycles to quantify end‐point saturations of scCO2 with the aid of micro‐ and macro‐computed tomography imaging. From these experiments, we found that between 51% and 75% of the initial CO2 injected can be left behind after the brine injection. We also observed that the initial scCO2 saturation influenced the residual scCO2 saturation to a greater extent than the rate of brine injection under the experimental conditions examined. In spite of differences in the experimental conditions tested, as well as those reported in the literature, initial and residual saturations were found to follow a consistent relationship.  相似文献   
33.
This paper investigates the paradox in post‐conflict societies of continued marginality of cross‐ethnic parties despite significant convergence in public attitudes and identities. In so doing, it examines the argument that parties that attempt to reach across the divide are constrained by consocational institutions designed to accommodate rival identities in such environments. The paper explores this puzzle in the context of Northern Ireland, drawing upon qualitative evidence from elite interviews and focus groups collected in 2012 and 2013. It concludes that cross‐community parties operating in the region do encounter formal institutional barriers, but that such barriers only partially explain the phenomenon and an interplay between formal and informal constraints underlies their position of relatively limited electoral success.  相似文献   
34.
Initiated by geoscientists, the growing debate about the Anthropocene, ‘planetary boundaries’ and global ‘tipping points’ is a significant opportunity for geographers to reconfigure two things: one is the internal relationships among their discipline's many and varied perspectives (topical, philosophical, and methodological) on the real; the other the discipline's actual and perceived contributions to important issues in the wider society. Yet, without concerted effort and struggle, the opportunity is likely to be used in a ‘safe’ and rather predictable way by only a sub‐set of human‐environment geographers. The socio‐environmental challenges of a post‐Holocene world invite old narratives about Geography's holistic intellectual contributions to be reprised in the present. These narratives speak well to many geoscientists, social scientists, and decision‐makers outside Geography. However, they risk perpetuating an emaciated conception of reality wherein Earth systems and social systems are seen as knowable and manageable if the ‘right’ ensemble of expertise is achieved. I argue that we need to get out from under the shadow of these long‐standing narratives. Using suggestive examples, I make the case for forms of inquiry across the human‐physical ‘divide’ that eschew ontological monism and that serve to reveal the many legitimate cognitive, moral, and aesthetic framings of Earth present and future. Geography is unusual in that the potential for these forms of inquiry to become normalised is high compared with other subjects. This potential will only be taken advantage of if certain human‐environment geographers unaccustomed to engaging the world of geoscience and environmental policy change their modus operandi.  相似文献   
35.
36.
37.
38.
39.
C. Weiss  M. Köster  S. Japp 《Archaeometry》2016,58(2):239-254
Yeha was a political and cultural centre of the Ethio‐Sabaean culture (D’MT) in northern Ethiopia and southern Eritrea. Part of the archaeological research deals with pottery of local, regional and imported origin. The research—investigations and examinations—tries to classify local pottery in two ways: first, by analysing the mineralogy of the temper using light microscopy and cathodoluminescence; and, second, by analysing the main element composition of the clay matrix using a scanning electron microscope with energy‐dispersive X‐ray detection (SEM–EDX). The cathodoluminescence shows that the temper material has differences in the colours of feldspars with a similar mineralogical composition. The results demonstrate that the pottery was produced by using local material that originates from various sources in the Yeha region and that the same raw materials were used in different types of pottery.  相似文献   
40.
We present the results of a multi‐method archaeometric study concerning the architectural elements reused in Monte Sorbo church (Sarsina, central Italy) between the eighth and ninth centuries AD . The provenance study has focused on classical marbles and stones, which clearly do not originate from the local Apennine geological formations and are thought to come from extra‐regional sources. A large fraction of the tested marbles is from Asia Minor, coming from both the Proconnesian district on Marmara Island and, probably, the Hasançavuslar site near Ephesus (Greco scritto). Of the four remaining marbles investigated, one is from the Carrara district and three are from different Greek quarrying areas, such as Mount Pentelikon (Athens) and the Thasos and Paros islands. The data also highlight the reuse of decorated gravestones made of Pietra di Aurisina as architectonic elements. This limestone is a fossiliferous carbonate stone outcropping in the Trieste Karst region (north‐eastern Italy), which was exploited by both the Romans and the Byzantines. The assignment of all of the columns of the central nave to the same source area provides an argument in favour of their provenance from a single monument, which was probably located in Sarsina or Ravenna, with the ‘colourful taste’ that is typical of the late Antonine and Severian periods.  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