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   4806篇
  免费   232篇
  国内免费   47篇
财政金融   353篇
工业经济   225篇
计划管理   780篇
经济学   1149篇
综合类   474篇
运输经济   88篇
旅游经济   210篇
贸易经济   472篇
农业经济   860篇
经济概况   473篇
信息产业经济   1篇
  2024年   8篇
  2023年   96篇
  2022年   60篇
  2021年   114篇
  2020年   218篇
  2019年   191篇
  2018年   169篇
  2017年   208篇
  2016年   205篇
  2015年   166篇
  2014年   297篇
  2013年   520篇
  2012年   313篇
  2011年   399篇
  2010年   304篇
  2009年   280篇
  2008年   272篇
  2007年   234篇
  2006年   236篇
  2005年   147篇
  2004年   118篇
  2003年   95篇
  2002年   84篇
  2001年   84篇
  2000年   42篇
  1999年   35篇
  1998年   26篇
  1997年   36篇
  1996年   32篇
  1995年   21篇
  1994年   17篇
  1993年   8篇
  1992年   11篇
  1991年   5篇
  1990年   2篇
  1989年   2篇
  1986年   2篇
  1985年   7篇
  1984年   9篇
  1983年   8篇
  1982年   1篇
  1981年   1篇
  1979年   1篇
  1978年   1篇
排序方式: 共有5085条查询结果,搜索用时 15 毫秒
61.
The tidal river management (TRM) approach is an indigenous management practice in the Southwest part of the Ganges-Brahmaputra delta in Bangladesh. This approach has a high potential for extending area under agriculture with a positive impact on sustainable production and consequently on sustainable land use planning. Until recently, no studies provide a quantitative assessment on agricultural benefits of TRM operation. In this study, we aim to assess the benefits of TRM operation by using innovative approaches such as comparing land use change, agricultural production and economic cost-benefit analysis for two scenarios (with and without TRM) in the Hari-Teka-Bhadra catchment. We found that the financial benefit of TRM operation was 85.5 million US dollar per year from the agriculture sector. The results are useful for promoting land use policy through TRM approach in achieving greater sustainability in the area.  相似文献   
62.
During their occupation of Sri Lanka (1640–1796) and following Sinhalese and Portuguese practices, the Dutch created an elaborate registration of people, estates, and labour services. The administrative records known as the thombos are incomparable in their level of detail, yet they have hardly been used for the purposes of demographic or economic history. This article describes the challenges involved in ‘decoding’ the thombos, that is, reconstructing the meaning of particular variables in the light of the prevailing legal pluralism in which Sinhalese common law and Roman-Dutch law co-existed uncomfortably. It also summarises research findings from a pilot study involving about two hundred small villages in Colombo province. Finally, it sketches research horizons, as the thombo ‘treasure’ holds great prospects for (comparative) studies into family systems and the impact of colonial rule on fertility and mortality.  相似文献   
63.
This study presents detailed evidence on the characteristics, processes, and consequences of land rental practices in a multi-ethnic rural society in Yunnan Province, Southwest China, which have rarely been explored. It contributes to the existing literature on land rental and control by considering the dimension of ethnicity. The findings show the following: Interethnic land rental is a very common and noteworthy feature in the selected Han-Jingpo multi-ethnic rural society. Han ethnic households rented and accumulated a large proportion of farmland and forestland from neighbouring Jingpo ethnic households. This was done to expand cash crops and timber forest, as opposed to the activities of Jingpo ethnic households. Interethnic land rental was mainly triggered by different development capabilities and attitudes towards agricultural commercialization supported by differences in resource assets due to ethnic living patterns and other dynamic socio-political reasons. Consequently, Jingpo ethnic households are experiencing an increasing income gap due largely to declines in farmland and forestland, while possibilities for positive interethnic interactions were found. These findings are relevant for rethinking land rental policies in China and also provide useful insights for rural sustainability in any multi-ethnic area where interethnic interactions of land or other resources coexist.  相似文献   
64.
Conservation Agriculture (CA) is advocated as an agricultural innovation that will improve smallholder famer resilience to future climate change. Under the conditions presented by the El Niño event of 2015/16, the implementation of CA was examined in southern Malawi at household, district and national institutional levels. Agricultural system constraints experienced by farming households are identified, and in response the technologies, structures and agency associated with CA are evaluated. The most significant constraints were linked to household health, with associated labour and monetary impacts, in addition to the availability of external inputs of fertiliser and improved seed varieties. Our findings show that such constraints are not adequately addressed through current agricultural system support structures, with the institutions surrounding CA (in both Government extension services and NGO agricultural projects) focusing attention predominantly at field level practice, rather than on broader system constraints such as education and health support systems. Limited capacity within local institutions undermines long term efforts to implement new technologies such as CA. It is vitally important that the flexibility of farmers to adapt new technologies in a locally-appropriate manner is not closed down through national and institutional aims to build consensus around narrow technical definitions of a climate-smart technology such as CA. To enable farmers to fully utilise CA programmes, interventions must take a more holistic, cross-sectoral approach, understanding and adapting to address locally experienced constraints. Building capacity within households to adopt new agricultural practices is critical, and integrating healthcare support into agricultural policy is a vital step towards increasing smallholder resilience to future climate change.  相似文献   
65.
论文重点分析了企业组织架构变革的动因和变革过程中应该注意的问题,在对案例进行系统剖析研究的基础上,对组织架构变革如何适应并推动公司可持续发展、变革的主要动力、变革的主要策略等方面进行了系统研究,并以此为基础,提出了企业组织架构变革的相关建议。  相似文献   
66.
以稻谷粤农丝苗为原材料,置于4种不同储藏模式下,具体如下:(1)15℃储藏240d。(2)30℃储藏240d。(3)以15℃为开端,与30℃交替储藏(60d交替1次)至240d。(4)以30℃为开端,与15℃交替储藏(60d交替1次)至240d。每隔60d检测1次,比较上述4种储藏模式下,稻米蒸煮品质和α-淀粉酶活力的变化趋势。研究结果表明:随着时间的延长和储藏温度的升高,稻米品质下降;在实验时间内,以低温为开端的变温模式的稻米品质要优于以高温为开端的变温模式,但差距逐渐减小。  相似文献   
67.
China has been conducting massive land consolidation (LC) projects since the late 1990s to ensure national food security which has been one of the common issues in the world. How the implementation of LC projects affects grain production stability is a question should be answered. Basing on an empirical analysis at the county level in Hubei Province, China, this paper separates the trend component and the fluctuation component from a time series of grain production over 1991-2016 using the H-P filtering method. Then we estimate the impacts of LC projects and climate change on the trend and fluctuation rate of grain production for the entire Hubei Province. Moreover, the effects on the production of different major crops for the central, eastern, southwestern, northwestern and northern areas are also examined, respectively. The results show that: (1) the production trends for five subareas and the whole area all have followed a trajectory of “increase-decrease-increase” from 1991 to 2016. The magnitude of fluctuation rate was large but became smaller in recent years. (2) The contribution of LC to the long-term trends of grain production for the entire samples in Hubei Province mainly benefits from the growth in the cultivated land area through LC; more LC investment and newly-added arable land area promote the sudden increase in grain production above the long-term trends, while the impacts of LC area are negative. (3) The impacts of LC on the major crop production vary across areas. LC exerts significant impacts on the production of major crops in the central and eastern Hubei, and this effect persists to the following year. Similarly, this influence also exists in the southwestern and northern area, while becomes insignificant in the following year. No significant effect of LC variables is found in the northwestern area. These findings may provide reference for the government to address LC inefficiency and food security problems, and an effective and innovative mechanism combining the agricultural production, land consolidation and meteorological factors needs to be established to ensure food security and long-term and stable agricultural production. In addition, the regional difference in natural conditions and LC orientations should also be considered.  相似文献   
68.
To advance the science and practice of implementing nature-based solutions in cities, it is important to examine the obstacles and provide means to overcome them. This paper presents a conceptual framework of policy needs for analysing the science of nature-based solutions’ implementation and connect it to the practice of their implementation that advances the literature by connecting well-researched gaps to a more innovative action-oriented policy development approach that we argue is required for embedding scaled-up nature-based solutions. We conceptualise and ground the policy needs framework of skills, knowledge and partnerships theoretically in current literature of NBS policy and planning and empirically in three European case study cities: Genk in Belgium, Glasgow in UK and Poznan in Poland. The cross-case study analysis points to the knowledge needs of systems’ thinking and solutions-oriented thinking as paramount for implementing nature-based solutions. Our analysis further points to the skills’ needs of negotiation and collaboration for administrative silo bridging and for forging multi-sectoral partnerships essential for planning, and co-managing NBS. We conclude with three ways forward to addressing the policy needs for implementation: first, cities can invest in tailored and targeted capacity building programs, second, institutional spaces need to be established that allow for collaborative learning through and for partnerships and third, cities need to chart governance innovations that promote evidence-based policy for nature-based solutions’ design and implementation.  相似文献   
69.
Climate change is likely to generate severe impacts on smallholder farmers in developing countries. As key drivers of adaptation, climate risk perceptions are highly heterogeneous, varying both across people and context, and are complex, being defined as behaviour which varies across both impact and likelihood dimensions in non-linear ways. Yet most studies examining risk perceptions are unable to disentangle the role of perceptions regarding impacts from those regarding the likelihood of climate-related events taking place. This paper presents a decomposition and associated analysis of survey-based ‘risk perception’ measures. The decomposition we apply allows independent accounting for perceptions over frequencies and impacts linking to behavioural patterns of risk attitude. The approach presented here draws on a detailed 2017 survey of 500 farmers in rural Indonesia to generate insights into the relationship between risk perceptions and extension services, accessibility of information, and other factors. Results show that risk perceptions are generated from complex interaction between perceived future frequencies and outcomes of climate events and indicate differential impacts of extension services across these perceptions. This paper also presents empirical support for the use of information and communication technology based extension as an efficient extension tool to reach more farmers than in traditional methods.  相似文献   
70.
Household size decline accounts for a substantial portion of population loss in shrinking cities, yet little research has focused on it. Much of the literature presents a simple growth/decline binary that is largely determined via population figures. In this paper, we highlight the importance and assess the impact of household size changes on population decline, and determine what types of household size declines are more acute in shrinking cities than other locales. We find that elderly households and households with school-aged children are under-represented in shrinking cities, while households with pre-school-aged children are over-represented. More tellingly, we find the biggest source of household-related loss in shrinking cities to be the growth of single-person households now living in houses that were once home to entire families. These findings puncture the binary on which much of the shrinking cities discourse is based. The population dynamics of most cities are subtler than either practitioners or critical scholars assert. We argue that plans and development strategies for shrinking cities should reflect a range of demographic changes, including outmigration and internal household restructuring.  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