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   2314篇
  免费   96篇
财政金融   242篇
工业经济   139篇
计划管理   198篇
经济学   549篇
综合类   138篇
运输经济   23篇
旅游经济   2篇
贸易经济   180篇
农业经济   561篇
经济概况   378篇
  2024年   1篇
  2023年   25篇
  2022年   47篇
  2021年   71篇
  2020年   151篇
  2019年   71篇
  2018年   52篇
  2017年   87篇
  2016年   95篇
  2015年   62篇
  2014年   161篇
  2013年   134篇
  2012年   170篇
  2011年   215篇
  2010年   145篇
  2009年   148篇
  2008年   164篇
  2007年   144篇
  2006年   156篇
  2005年   74篇
  2004年   53篇
  2003年   25篇
  2002年   22篇
  2001年   25篇
  2000年   27篇
  1999年   15篇
  1998年   13篇
  1997年   5篇
  1996年   9篇
  1995年   2篇
  1994年   6篇
  1993年   4篇
  1992年   3篇
  1991年   1篇
  1990年   1篇
  1986年   1篇
  1985年   6篇
  1984年   6篇
  1983年   6篇
  1982年   7篇
排序方式: 共有2410条查询结果,搜索用时 15 毫秒
71.
Land consolidation has been an important instrument of rural development for over a century throughout Europe. Nowadays, land consolidation can be an integral part of both rural and urban development projects, but the focus of our study is on land consolidation in rural areas. In addition to the efforts aimed at making agriculture and forestry more competitive through a comprehensive reallocation process, improvement of road and drainage networks, landscaping, environmental management, conservation projects, and other functions may be implemented in land consolidation. There are differences in the objectives and procedures of land consolidation among the countries. Beside the formal institutional framework of land consolidation, informal institutions can have a substantial influence on the implementation of land consolidation. In the article, the past experiences in the field of land consolidation in Slovenia are presented, which are still reflected in the limited acceptability of this instrument among land owners. Furthermore, the current institutional (legal) framework is analyzed in detail. The main objective of the research was to investigate the opinion of land consolidation participants about land consolidation. Based on the field survey conducted on a sample of private land owners involved in selected land consolidation projects we tried to define the advantages and disadvantages of the current practice. The main finding is that the active participation of land owners contributes to their comprehension of the aims and to their satisfaction with the results of the land consolidation. It has been shown that the active participation of land owners in the land consolidation is the basis for developing good practices; moreover, it affects the land owners’ perception of land consolidation. The transfer of knowledge and representation of good practices among actors are still needed, in particular because of bad experiences in the past (i.e. enforced and environmentally unfriendly projects) and the traditional emotional attachment to land among land owners. In parallel, there is a great need to provide an optimization of the land consolidation process in Slovenia.  相似文献   
72.
Many agricultural practices are negatively impacting the environment and threatening the ecological foundations of the global food system. Therefore, agroecological practices are being proposed as viable and desirable alternatives. Biophysical, economic, social, and political factors, matched with farmers’ psychological attributes, may all be governing the choice of agricultural practices. Public policies can play a significant role as they can stimulate the adoption of innovative farming practices. The main objective of this research was the evaluation of farmers’ motivations for the adoption of agroecological practices in the viticulture sector in the province of Trento, Italy. A specific focus was laid on the influences from the European Common Agricultural Policy (CAP) measures. For the evaluation of farmers’ perceptions of their systems of practices, the Cognitive Mapping Approach for Analysing Actors’ Systems Of Practices (CMASOP) was applied. Based on information collected during in-depth interviews, Individual and Social Cognitive Maps were generated, representing the most frequently adopted agroecological practices and the major drivers of adoption of such practices, as mentioned by farmers. Drivers of adoption were categorized according to the self-determination theory of human motivations. Farmers reported that adoption of agroecological practices was mainly driven by existence of site-specific pedoclimatic conditions, followed with decreasing importance by requirements from wineries, availability of material, appreciation for aesthetics, health concerns, influence from irrigation consortia, and legal requirements, among which a local legislation for integrated pest management based on a CAP measure. Overall, results show that farmers reported to adopt agroecological practices mainly because of autonomous choices rather than coercion. Therefore, wineries and local policy-makers might incentivize the adoption of agroecological practices by promoting autonomy-supportive policies that foster farmers’ identified and intrinsic motivations.  相似文献   
73.
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   
74.
In the late 1990s, China aimed to mitigate environmental degradation from agricultural production activities by introducing the world's largest “Payments for Environmental Services? program: the Sloping Land Conversion Program (SLCP). We develop a microeconomic Agricultural Household Model, which can model the production, consumption, and nonfarm labor supply decisions of agricultural households in rural China in a theoretically consistent fashion. Based on this theoretical model, we derive an empirical specification, which we econometrically estimate using the Hausman–Taylor method and a large longitudinal farm household data set. The empirical results significantly differ between regions, but are generally consistent with the results of our theoretical comparative static analysis, for example, that the SLCP significantly decreases agricultural production. While the SLCP only increases nonfarm labor supply and total consumption in some regions, these effects could not be observed in others. The recent reduction of the SLCP compensation payment rates generally had negligible effects on agricultural production and off‐farm work and only very small effects on household consumption.  相似文献   
75.
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   
76.
Using data for a long panel of 90 developed and developing countries, this article explores the effects of research and development (R&D) and fixed capital stock on agricultural land productivity over the period 1961–2012. Instruments are used for R&D to deal with feedback effects and measurement errors. The results show very high social returns to investment in R&D and to fixed capital stock, suggesting that increasing investment in these factors are promising ways of arresting the increasing food prices due to increasing demand for animal protein, population growth, desertification, salinization, soil erosion, climate change, and decreasing growth in land productivity.  相似文献   
77.
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   
78.
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   
79.
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   
80.
Climate policies have stochastic consequences that involve a great number of generations. This calls for evaluating social risk (what kind of societies will future people be born into) rather than individual risk (what will happen to people during their own lifetimes). We respond to this call by proposing and axiomatizing probability adjusted rank-discounted critical-level generalized utilitarianism (PARDCLU) through a key axiom ensuring that the social welfare order both is ethical and satisfies first-order stochastic dominance. PARDCLU yields a new useful perspective on intergenerational risks, is ethical in contrast to discounted utilitarianism, and avoids objections that have been raised against other ethical criteria. We show that PARDCLU handles situations with positive probability of human extinction and is linked to decision theory by yielding rank-dependent expected utilitarianism—but with additional structure—in a special case.  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