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   1976篇
  免费   107篇
  国内免费   13篇
财政金融   135篇
工业经济   142篇
计划管理   171篇
经济学   287篇
综合类   266篇
运输经济   10篇
旅游经济   2篇
贸易经济   158篇
农业经济   608篇
经济概况   317篇
  2024年   9篇
  2023年   26篇
  2022年   40篇
  2021年   63篇
  2020年   125篇
  2019年   50篇
  2018年   43篇
  2017年   72篇
  2016年   80篇
  2015年   60篇
  2014年   141篇
  2013年   121篇
  2012年   135篇
  2011年   170篇
  2010年   124篇
  2009年   136篇
  2008年   139篇
  2007年   103篇
  2006年   130篇
  2005年   74篇
  2004年   52篇
  2003年   42篇
  2002年   32篇
  2001年   34篇
  2000年   27篇
  1999年   17篇
  1998年   10篇
  1997年   3篇
  1996年   1篇
  1994年   6篇
  1993年   3篇
  1992年   2篇
  1990年   1篇
  1986年   1篇
  1985年   6篇
  1984年   5篇
  1983年   6篇
  1982年   7篇
排序方式: 共有2096条查询结果,搜索用时 531 毫秒
31.
Natural vegetation enhances the value of agricultural landscapes for people and wildlife. However, the role of anthropogenic versus topographic factors in driving the extent of natural vegetation cover within agricultural lands at large spatial scales remains unexplored. I assessed the influence of anthropogenic and topographic variables on the extent of agricultural mosaics with high natural vegetation cover in the country of Turkey where a large extent of natural and semi-natural vegetation is maintained by traditional agriculture. GIS layers depicting human land use, elevation, slope, roads and population data were obtained and summarized at two spatial scales, within provinces and for 100 km2 grid cells covering the country’s entire agricultural land area. Average farm size was also obtained at province level. Hierarchical Partitioning was conducted to determine the independent effect of anthropogenic and topographic variables on the variation in agriculture with high natural vegetation. Slope had the largest independent effect on the variation in the proportion of agricultural mosaic with high natural vegetation cover. The extent of agricultural and settlement area also explained much of the variation in natural vegetation across both grid cells and provinces. The proportion of natural vegetation increased as human population and road density decreased across grid cells and as average farm size decreased across provinces. These results suggest that while topography is the primary driver of natural vegetation cover within agricultural mosaics in Turkey, the pressures associated with urban development and agricultural industrialization may also influence the cultural and wildlife value of agricultural landscapes.  相似文献   
32.
Problems in agriculture and land use are increasingly recognised as complex, uncertain, operating at multiple levels (field to global value chains) and involving social, economic, institutional, and technological change. This has implications for how projects navigate complexity to achieve impact. However, few studies have systematically evaluated how project actors engage with other actors to configure capabilities and resources across multiple levels in agricultural innovation systems (AIS), from the individual to the network, to mobilise and build systemic innovation capacity. An analytical framework conceptualising the nested configuration of capabilities at multiple levels in the AIS is applied to two projects that successfully tackled agricultural and land management problems of differing complexity: (i) improving lamb survival; and (ii) sustainable land management in New Zealand. Findings indicate that innovation capacity constitutes project actors interacting with other AIS actors to configure capabilities and resources at different levels of the AIS in order to leverage positive project path dependencies and break path dependencies that are created by existing and historical capability configurations. Project actors also balance exploiting existing innovation capabilities, as well as using adaptive capability for exploring and creating new capability configurations to respond to emerging circumstances. This implies that projects should have strategic ambidexterity in terms of how they combine exploiting existing and exploring new networks to access, combine, create, or disconnect certain capabilities to address ‘capability voids’ in AIS. This requires support to projects to constantly scrutinise, through reflexive monitoring by dedicated facilitators, specific agriculture and land use policies connected to major sustainable development models (e.g. climate smart agriculture, urban farming, smart farming). The can help assess whether the AIS provides the right mix of capabilities and whether this is adequately supported by innovation policy, to realize transformative policy objectives.  相似文献   
33.
The apparent success of state‐managed market economies has challenged the conventional wisdom that liberal democracy is the norm around which all capitalist countries tend to converge. If the link between democracy and development is more tenuous than we often think, the authoritarian variety of capitalism is not without its own problems, especially with respect to political legitimacy, innovation and regional development. This article explores these issues through the prism of ‘authoritarian modernization’ in Russia. We argue that this strategy is unlikely to succeed, even in its own terms, because (1) the political system fails to create favourable institutional conditions for modernization; (2) the economic system is beset by deeply embedded structural problems; and (3) the regional policy apparatus is torn between the goals of spatial equalization and spatial agglomeration. The article focuses on the Skolkovo Innovation Centre, the main symbol of Russian modernization, to demonstrate the territorial repertoire of the mega‐project, a state‐sponsored development strategy to create innovation clusters from above because they cannot emerge from below.  相似文献   
34.
Human-driven land-use changes often cause a decline in biodiversity. Although traditional agricultural practices maintained biodiversity at high levels, recent land-use changes may have negative consequences on species composition. In this study, we examined the hypothesis that land consolidation, which is a major recent land-use change in agricultural areas, decreases plant species diversity over the long term (the so-called negative legacy). To test this hypothesis, we examined the relationships between consolidated areas and the occurrence of threatened plant species across Japan and at the prefecture scale. Twenty-three threatened plant species were selected, all of which were formerly common. Our results show that areas containing records of threatened plant species rarely experienced consolidation at whole-country and prefectural scales. Breakdown analysis showed that unconsolidated agricultural areas contained significantly more threatened species than consolidated agricultural areas. These results suggest that threatened plant species require unconsolidated agricultural areas (i.e., these species could not grow in consolidated areas). Thus, we propose that consolidation history could be used as an indicator of the potential for biodiversity recovery. We also suggest that consolidated agricultural areas should be used for food production rather than for the restoration of biodiversity, for reasons of cost efficiency.  相似文献   
35.
The policy environment for the Irish agri‐food sector could change rapidly in the coming decade. A potentially positive factor will be the elimination of milk quotas in 2015, although a potentially negative factor will be further trade liberalisation and increased import competition. These changes come on top of the move to decouple direct aids to farmers in 2005 as part of the Mid‐Term Review of the EU's Common Agricultural Policy agreed in 2003. This paper examines these reforms and their impacts on the Irish economy and income distribution using a CGE model particularly rich in detail on the agri‐food sectors, differentiated household groups, and agricultural policy instruments including their links to productive factors and households. The results suggest that the past and projected changes in the policy environment have, in sum, a small positive impact on GDP and household income. However, the gains and losses are unequally distributed across sectors and household groups due to the highly differentiated distribution of support and protection. Although all households generally gain from the sequence of policy reforms in the long run, some experience strong adverse effects from particular reforms and in the medium term.  相似文献   
36.
North America has few cultural agricultural landscapes, and often commensurately poor governance arrangements for managing change in such settings. This research uses the Acadian dykelands of Nova Scotia, Canada, as an opportunity to explore the social and governance limits to coastal climate adaptation in ‘new world’ cultural agricultural landscapes, as well as inform local decision-making. Approximately half of Nova Scotia’s coastal wetlands were converted to dykeland in the 1600s, lowering local resilience to the increased frequency and storm severity anticipated with climate change. Today, dykelands protect a diversity of public and private interests, meanings and values, yet are controlled by the agricultural sector, which can no longer afford to maintain them all to 2050 climate projections. We report here on a representative online Q-methodology survey of 183 adult Nova Scotians in the spring of 2015. Respondents sorted 34 statements along a normal distribution about whether they prefer dykeland maintenance or wetland restoration, and under what governance arrangements. Four factors were derived: the dominant discourse was local, female and strongly pro-dykeland, indicating the likelihood for local resistance to dykeland removal on for cultural, recreational and farming reasons. The second factor was supportive of wetland restoration for reasons of efficiency, not wetland affinity, but characterized by those in positions of management power. The two minority viewpoints were less informed about dykelands, characteristic of outsiders, and concerned more with governance. More education is needed about the challenges facing dykelands, the benefits of coastal wetlands, and the management options, but this research shows proposals to change landscape should emphasize flood mitigation over cost-saving. Cultural values and status quo bias are clearly barriers to adaptation planning, even when discussing the removal of man-made structures. The factors were surprisingly polarized, suggesting the forced-normal distribution affects the space available to convey nuanced perspectives. Large p-set Q-method of this kind is likely most useful for characterizing the emergent discourses demographically, and understanding their prevalence; the same discourses had emerged within a much smaller pilot study.  相似文献   
37.
This study examines the nature of the relationship between formal agricultural credit and agricultural Gross Domestic Product (GDP) in India, specifically the role of the former in supporting agricultural growth, using state level panel data covering the period 1995–1996 to 2011–2012. The study uses a mediation analysis framework to map the pathways through which institutional credit relates to agricultural GDP relying on a control function approach to tackle the problem of endogeneity. The findings from the analysis suggest that over this period, all the inputs are highly responsive to an increase in institutional credit to agriculture. A 10% increase in credit flow in nominal terms leads to an increase by 1.7% in fertilizers (N, P, K) consumption in physical quantities, 5.1% increase in the tonnes of pesticides, 10.8% increase in tractor purchases. Overall, it seems quite clear that input use is sensitive to credit flow, whereas GDP of agriculture is not. Credit seems therefore to be an enabling input, but one whose effectiveness is undermined by low technical efficiency and productivity.  相似文献   
38.
The UK Brexit vote triggered a new wave of policy developments for a future outside the EU. In this context, we analyse the business performance of English hill and upland farms, characterised by marginal economic conditions but also high nature value (HNV). The analysis aims to help identify farm-level management and policy options for greater economic, environmental and social sustainability. Business performance is measured as technical efficiency and the occurrence and persistence of abnormal profits, estimated through stochastic frontier analysis and static and dynamic panel-data methods. The results help indicate rationales for recent trends including farm enlargement, farm family diversification, and agri-environment scheme entry. The single farm payment is found to be negatively associated with farm technical efficiency while agri-environmental subsidies were positively associated to short-term farm profitability. Farm adaptation and resilience during a period of likely turbulence in external circumstances is discussed in light of these findings, as well as potential parallels with marginal HNV areas across Europe.  相似文献   
39.
Analysis of the joint production of private and public goods (PGs) by farming activities is a fertile research field. These joint production processes are typically characterised by a high level of complexity derived from the intense relationship between the production of both kinds of outputs. An integrated approach is strongly recommended for the study of the provision of agricultural PGs and the design of public intervention in this sector. Here, we propose a theoretical framework to apply an integrated approach using the analytic network process (ANP) to analyse the production of PGs by agricultural systems to support public decision-making concerning the design and implementation of agricultural policies. We introduce a novel approach in applying ANP along both directions of the influences among elements, allowing us to identify the most influenced PGs and the farmers’ most influential decisions. This methodological approach is empirically applied to a particular farming system: the irrigated olive groves (IOG) of Southern Spain. Results show that the PGs most influenced by olive growers’ decisions are soil fertility, the visual quality of agricultural landscapes and farmland biodiversity. In addition, the most influential factors affecting the provision of PGs are the structural ones, namely farm size and tree density, and, to a lesser extent, management factors dealing with fertilisation, soil and irrigation management. These results are useful for supporting agricultural policy decision-making to enhance adequate management of this farming system regarding PGs production.  相似文献   
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