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   45337篇
  免费   1938篇
  国内免费   578篇
财政金融   3452篇
工业经济   2061篇
计划管理   10817篇
经济学   8005篇
综合类   7050篇
运输经济   411篇
旅游经济   849篇
贸易经济   5284篇
农业经济   4073篇
经济概况   5851篇
  2024年   79篇
  2023年   611篇
  2022年   862篇
  2021年   1376篇
  2020年   1666篇
  2019年   1025篇
  2018年   861篇
  2017年   986篇
  2016年   1126篇
  2015年   1348篇
  2014年   3346篇
  2013年   3719篇
  2012年   4041篇
  2011年   4896篇
  2010年   3617篇
  2009年   2967篇
  2008年   2962篇
  2007年   2501篇
  2006年   2382篇
  2005年   1749篇
  2004年   1260篇
  2003年   1084篇
  2002年   783篇
  2001年   762篇
  2000年   518篇
  1999年   308篇
  1998年   148篇
  1997年   130篇
  1996年   112篇
  1995年   86篇
  1994年   64篇
  1993年   61篇
  1992年   53篇
  1991年   46篇
  1990年   28篇
  1989年   19篇
  1988年   24篇
  1987年   5篇
  1986年   5篇
  1985年   41篇
  1984年   64篇
  1983年   47篇
  1982年   36篇
  1981年   15篇
  1980年   14篇
  1979年   11篇
  1978年   2篇
  1977年   6篇
  1973年   1篇
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
51.
In Australia and in many parts of the world, older people participate in line dancing. Our phenomenological study explored whether attending a regular line dancing class might offer a group of older people opportunities for active and successful ageing. Our research investigated the meanings and practices fostered in a community line dancing class in Melbourne. We gathered data via an interview with the teacher of the group, observation of a class and two focus group interviews with 25 members. Data were analysed using Interpretative Phenomenological Analysis that is reported thematically under headings of: Belief in the efficacy of line dancing, Physical and emotional benefits, YouTube clips as instructional reinforcement and promotion, and Socialising. The findings show that participation in the class offered older student’s opportunities for dance and music engagement, active and successful ageing, health and well-being, social connection and purposeful leisure. The teacher of the class modelled serious and successful leisure and advocates for dance as holistic training for older people. We position our participants on a continuum of leisure engagement that ranges from the casual to the serious. Further research is required to support arguments for the efficacy of dance as a leisure pursuit for older adults.  相似文献   
52.
[目的]恶劣的生态环境和有限的资源驱动着新疆特殊生态系统服务的形成,人类又通过对生态系统服务的消费来满足和提高自身福祉,需要研究其时空变化并辨识主要驱动因素,支持区域可持续发展。[方法]文章构建了融合不同土地利用类型生态系统服务的价值量排序及服务功能强度矩阵的生态系统服务评估体系,并耦合3种关键驱动因子以评估各个因子的驱动强度,实现对生态系统服务热点与冷点变化的驱动及迁移分析。[结果]2000—2010年全疆生态系统服务总体增加,这一时期生态系统服务的热点区大部分转变为2010—2015年的冷点区,且15年来生态系统服务总体呈现小幅下降趋势。3个时期北疆和南疆人为干扰强度均呈增加趋势,由其驱动的生态系统服务则相应减小;南疆地区植被覆盖范围极其有限,故对生态系统服务驱动强度低;降水在北疆和南疆都能够产生高生态系统服务,但降水量的不稳定性能够使生态系统服务产生较大波动。相比于南疆地区,北疆生态系统在外界干扰下能够体现出更强的抗性和整体性,从而实现相对高效的生态系统服务输出。[结论]对关键驱动因子作用下的生态系统服务进行时空变化分析,有助于理解当地生态系统产生变化的原因,从而为当地生态环境保护提供参考。  相似文献   
53.
54.
自然资源资产管理:理论逻辑与改革导向   总被引:1,自引:0,他引:1  
研究目的:针对自然资源资产管理的理论诠释不清、改革导向不明、自然资源的资产属性尚未充分体现等问题,本文立足新时代党和国家机构改革背景,分析自然资源资产管理的理论逻辑,明确未来自然资源资产管理的改革方向。研究方法:文献研究法,综合分析法。研究结果:新时代自然资源资产管理应当基于"权利—价值—经营—管理"的理论逻辑体系框架,其中自然资源资产权利应当包含自然资源资产所有权、资格权、使用权和管理权等对象内涵,以完整、明晰和稳定作为权利实现要求;自然资源资产价值显化应当基于生态、经济等价值的全面认知,针对不同资产类型分类采用不同价值评估方法,完善市场培育、价值调节和公平分配机制;自然资源资产经营既要保障粮食安全、生态安全和规避可能风险,又要实现高品质利用,因而应当以底量保安全,以存量、数量、质量、差量和流量保协同,优化完善编制资产负债表;自然资源资产管理则应当打破自然资源资产管理割裂的现状,实现系统统一管理并建立全平台、全过程、全资源和全空间的综合监督机制。研究结论:自然资源资产管理应以"三维立体多权化"、"生态价值具象化"、"安全品质六量化"和"系统监管综合化"为改革导向,以期全面推进未来多维、绿色、高效、安全、品质、有序的自然资源资产管理方式的切实实现。  相似文献   
55.
This paper investigates the impacts of different network ties on export propensity of Vietnamese small and medium enterprises (SMEs) in the manufacturing sector. Using data from a survey of over 2,600 manufacturing SMEs in 2015, we found that social networks contribute positively to the export propensity of SMEs, while the size of business networks negatively associates with the likelihood of export. However, bank networks and political networks are not significant for the propensity to export of Vietnamese SMEs. We discuss the results in detail and offer recommendations for SME owners, managers and policy makers.  相似文献   
56.
Domestic credit expansion in CEE economies, fuelled in part by foreign capital inflows, helped increase household welfare before the 2008 financial crisis caused a contraction across the region. How strong are the linkages between the current account, domestic credit and consumer spending? This study compiles a quarterly dataset of domestic credit as a share of GDP for 11 CEE European Union members and isolates structural breaks in the series’ growth rates that often align with the 2008 crisis. Vector autoregressive methods, particularly impulse response functions, show that increased current-account deficits lead to increased consumption in six of the 11 countries and increased credit growth in three, and that shocks to credit growth increase consumption in six countries. Capital inflows significantly increase consumption through domestic credit in Slovenia, while the Baltics show a large share of significant effects.  相似文献   
57.
We examine the effect of simultaneous price changes on the total demand for a group of goods, which we call a compound commodity. Specifically, we consider unit and proportional cost components (e.g., taxes, transportation costs) imposed on compound commodities. If the unit cost is positive, then the proportional cost raises the relative price of the more expensive good, and thus induces substitution towards the less expensive good within this group. Then, the substitution effect of the proportional cost for a compound commodity is non‐negative if and only if the compound commodity and the other goods are, on average, not strongly substitutable.  相似文献   
58.
The objective of this article is to summarize and review the literature on the determinants of road traffic injuries and fatalities, to identify the relevant research gaps in particular for low and middle income countries. We also present a cross-country analysis of the determinants of road traffic injuries and fatalities that take into account a wide range of potential environmental, economic and social factors. The present study focused on differences based on the level of development. The goal was to identify relevant commonalities that may assist in the creation of road safety policies common to countries at a similar level of development. The countries were divided according to the level of gross national income per capita, and these income-level groups were the primary units of interest. The results presented here focus on the differences by income level.  相似文献   
59.
以阿里巴巴和杭州未来科技城为例,采用Logistic模型探讨锚企业与科技新城共生模式,结果表明:总体而言,阿里巴巴和未来科技城属于互利共生模式,阿里巴巴成长会促进未来科技城发展,而未来科技城发展也会反哺阿里巴巴的成长。2013-2016年两者共生系数之间的差值不断缩小,表明阿里巴巴和杭州未来科技城的共生模式从偏利共生转向互利共生。  相似文献   
60.
In the early 1980s, disease susceptibility in short-season lentil landraces began to limit productivity in areas where relay cropping took place in Bangladesh. Since then, several improved high-yielding lentil varieties, which are resistant to rust and blight and suitable in the relay cropping system, have been released jointly by national and international research centers. This study used three methods, namely a panel of experts, a survey of 1000 households where the respondents named the variety they used, and DNA fingerprinting of seed samples collected from all lentil plots cultivated by survey households to estimate adoption. Double hurdle and instrumental variables regression methods were applied to the household survey and DNA fingerprinting data to identify determinants of adoption and measure their impacts. Of particular interest was whether estimates of adoption, determinants of adoption and impacts varied by method of variety identification. Results showed that the expert panel overestimated the adoption of more recent varieties while about 89% of the farmer-reported varieties were accurate, as verified by DNA fingerprinting. DNA fingerprinting appears to have little advantage for estimating the level of adoption in this case, where few varieties of lentils are found, local variety names do not exist, and most seed is obtained through a formal system. However, even under these conditions, determinants of adoption vary by identification method, and use of farmer-reported information on the variety can lead to erroneous conclusions about determinants of adoption. Because recent breeding efforts have focused on taste and cooking considerations, yield impacts were not significantly different from zero.  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