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   1429篇
  免费   410篇
  2024年   1篇
  2023年   2篇
  2022年   7篇
  2021年   31篇
  2020年   33篇
  2019年   151篇
  2018年   121篇
  2017年   121篇
  2016年   133篇
  2015年   127篇
  2014年   115篇
  2013年   258篇
  2012年   130篇
  2011年   117篇
  2010年   87篇
  2009年   42篇
  2008年   75篇
  2007年   65篇
  2006年   40篇
  2005年   37篇
  2004年   33篇
  2003年   32篇
  2002年   22篇
  2001年   29篇
  2000年   20篇
  1999年   4篇
  1998年   2篇
  1997年   3篇
  1992年   1篇
排序方式: 共有1839条查询结果,搜索用时 15 毫秒
31.
Ashanté M. Reese 《对极》2018,50(2):407-424
Drawing from 18 months of ethnographic fieldwork in Washington, DC, this article outlines geographies of self‐reliance; a theoretical framework for understanding black food geographies that are embedded in histories of self‐reliance as a response to structural inequalities. Using a community garden as a case study, I argue that the garden functions as a site for addressing several manifestations of structural violence: racist and classist depictions of low‐income and working class people, joblessness, gentrification, and youth underdevelopment. Drawing on self‐reliance ideologies as well as collective and personal histories, the residents exhibit a form of agency that demonstrates unwavering hope in the sustainability of their shared community. Through this analysis, I show that self‐reliance functions as a mechanism through which residents navigate spatial inequalities.  相似文献   
32.
Policy advocacy is an increasingly important function for many nonprofit organizations, yet their advocacy activities have largely escaped theoretical grounding. The literature on nonprofits has described how they engage in policy advocacy, without linking them to theories of policy change. The policy studies literature, on the other hand, has explained how various forms of influence result in policy change, but has largely ignored organizational perspectives on those processes. These two literatures remain largely disconnected. Drawing upon interviews with a purposive sample of policy advocacy directors at 31 nonprofit organizations, this study applies Q‐methodology to identify and describe six distinct policy advocacy strategies employed by the organizations, and their resonant theoretical views of policy processes. These findings suggest strategic approaches for nonprofits seeking to influence policy processes. They also enhance the academic literature on policy processes by adding the advocates’ views and expectations. Implications for further research are also identified.  相似文献   
33.
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   
34.
Abstract

Famines in the years immediately after World War II occurred during a period of global flux, as international famine response evolved from its ambitious, early twentieth century goals toward more modest, technocratic objectives during the second half of the century. For economists, social scientists and politicians immersed in the world of emergency food aid, these were uncertain, awkward years for famine relief. Herbert Hoover’s idealistic large-scale projects of famine relief that had dominated the first three decades of the century had been proven to be expensive and of limited efficacy, but Cold War loyalties had not yet taken over as the primary logic behind large-scale humanitarian assistance projects. Ultimately, when faced with famine conditions between 1944 and 1947, states and experts balanced a call to action against pragmatism that recognized famines were also politically expedient events that could weaken rural resistance to governance and simplify wartime and postwar administration. Ultimately, both science and humanitarian concerns learned to orient themselves toward economic expediency in these awkward years.  相似文献   
35.
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   
36.
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   
37.
Abstract

A consistent access to food is paramount for humans at individual and group level. Besides providing the basic nutritional needs, access to food defines social structures and has stimulated innovation in food procurement, processing and storage. We focus on the social aspects of food storage, namely the role of cooperation for the emergence and maintenance of common stocks. Cooperative food stocks are examined here as a type of common-pool resource, where appropriators must cooperate to avoid shortage (i.e. the tragedy of commons). ‘Food for all’ is an agent-based model in which agents face the social dilemma of whether or not to store in a cooperative stock, adapting their strategies through a simple reinforcement learning mechanism. The model provides insights on the evolution of cooperation in terms of storage efficiency and considering the presence of social norms that regulate reciprocity. For cooperative food storage to emerge and be maintained, a significant dependency on the stored food and some degree of external pressure are needed. In fact, cooperative food storage emerges as the best performing strategy when facing environmental stress. Likewise, an intermediate control over reciprocity favours cooperation for food storage, suggesting that concepts of closed reciprocity are precursors to cooperative stocks, while excess control over reciprocity is detrimental for such institution.  相似文献   
38.
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   
39.
40.
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