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   1782篇
  免费   57篇
财政金融   443篇
工业经济   140篇
计划管理   305篇
经济学   272篇
综合类   8篇
运输经济   24篇
旅游经济   61篇
贸易经济   327篇
农业经济   91篇
经济概况   168篇
  2023年   11篇
  2021年   12篇
  2020年   25篇
  2019年   32篇
  2018年   40篇
  2017年   34篇
  2016年   52篇
  2015年   20篇
  2014年   48篇
  2013年   313篇
  2012年   41篇
  2011年   64篇
  2010年   66篇
  2009年   62篇
  2008年   60篇
  2007年   57篇
  2006年   47篇
  2005年   44篇
  2004年   56篇
  2003年   57篇
  2002年   56篇
  2001年   29篇
  2000年   48篇
  1999年   32篇
  1998年   39篇
  1997年   37篇
  1996年   22篇
  1995年   23篇
  1994年   31篇
  1993年   23篇
  1992年   20篇
  1991年   20篇
  1990年   20篇
  1989年   18篇
  1988年   13篇
  1987年   17篇
  1986年   24篇
  1985年   31篇
  1984年   20篇
  1983年   22篇
  1982年   10篇
  1981年   19篇
  1980年   12篇
  1979年   18篇
  1978年   9篇
  1977年   13篇
  1976年   12篇
  1975年   10篇
  1974年   7篇
  1972年   7篇
排序方式: 共有1839条查询结果,搜索用时 31 毫秒
61.
The objective of this study was to conduct empirical comparisons between two models of optimal experience within an on-site whitewater kayaking setting using a modification of the Experience Sampling Method. Four concerns are examined: (1) differences in explanatory power between the four channel flow model and the Adventure Experience Paradigm, (2) convergent validity among measures used to determine conditions within these models, (3) differences among measures of perceived challenge and risk between test times of Class I-V river difficulty, and (4) differences among measures of perceived skill and competence between test times of Class I-V river difficulty. Questionnaires were administered in the Cheat River Canyon in West Virginia to 52 whitewater kayakers at eight sites of various levels of river difficulty. Data were analyzed at the experience level, rather than between subjects, using 409 experience sampling observations. Hypothesis testing, performed with statistical analyses (stepwise regression, correlations, and repeated measures ANOVA), suggested that the explanatory powers of the four channel flow model and Adventure Experience Paradigm were similar and indicated support for convergent and ecological validity of measures used to determine conditions within each of the two models.  相似文献   
62.
63.
The case for promoting export‐oriented cash crops in Africa has generally been based on their direct potential contribution to agricultural productivity and small farmer incomes. A relatively neglected avenue of research concerns the synergistic effects that cash cropping can have on other household activities, including food production. The conventional view that cash crops compete with food crops for land and labour neglects the potential for cash crop schemes to make available inputs on credit, management training, and other resources that can contribute to food crop productivity, which might otherwise not be accessible to farmers if they did not participate in cash crop programs. This article builds on previous research by hypothesising key pathways by which cash crops may affect food crop activities and empirically measuring these effects using the case of cotton in Gokwe North District in Zimbabwe. Analysis is based on instrumental variable analysis of survey data on 430 rural households in 1996. Results indicate that—after controlling for household assets, education and locational differences—households engaging intensively in cotton production obtain higher grain yields than non‐cotton and marginal cotton producers. We also find evidence of regional spill‐over effects whereby commercialisation schemes induce second round investments in a particular area that provide benefits to all farmers in that region, regardless of whether they engage in that commercialisation scheme. The study suggests that the potential spill‐over benefits for food crops through participation in cash crop programs are important to consider in the development of strategies designed to intensify African food crop production.  相似文献   
64.
Children with developmental disabilities participate in more solitary, sedentary, and home-based leisure activities than active physical pursuits or community-based activities. Clinical experience suggests that children with less well-recognized developmental difficulties also have compromised leisure experiences; however, this has not been fully investigated. This study engaged 20 school-age children with developmental difficulties in a community-based circus program, designed in collaboration with occupational therapists. The program included activities such as trampolining, trapeze, and acrobatics. Semi-structured interviews with children and parents explored children's leisure experiences both at circus and more broadly. Qualitative content analysis revealed that friendships, having fun, and being physically active were highly valued aspects of leisure. The coaching style and “just right” level of challenge within programs were identified as central to children's engagement and sense of competence. Participating in a supported leisure program such as circus appeared to promote children's engagement in community leisure, at least in the short term.  相似文献   
65.
This paper analyzes television commercials (TVCs) launched by Korea Tourism Organization (KTO) from 1999 to 2012. By repeating shots of traditional and Korean popular (k-pop) culture, high-tech machinery, and sportsmanship, it is fair to say that Korean tourism TVCs both reflected and fueled the fad a target audience has for Korea. Hence the commercials not only promoted tourism, they were also projecting national power in general and cultural power in particular. It is surmised that through power projection the TVCs intend to create a country halo effect so that the country’s products and services may enjoy an aspired added value.  相似文献   
66.
In 2015, the Federal Communications Commission (FCC) imposed common carriage regulation—so-called Title II requirements—on previously unregulated broadband Internet service providers. The regime shift was premised on the FCC’s findings that such rules had demonstrably yielded economic gains. This paper evaluates the FCC’s empirical arguments and finds them uncompelling. Adjustments for inflation or general economic trends eliminate the effects cited by the FCC. Moreover, contrary to the Commission’s assessment, mobile services and broadband markets have shown notable growth in response to deregulatory events that reduce Title II requirements.  相似文献   
67.
Real estate investment portfolios of financial institutions have seen dramatic changes over the last three decades or more. Historically such property investment decisions have been seen within a portfolio diversification paradigm that has sought to balance risk and return. This paper considers the role of the supply of assets in the determining and constraining the UK institutional portfolio. The supply of real estate assets not only expands during property booms but has also been transformed by a long term urban development cycle as cities adapt to cars and the ICT revolution that has brought new property forms. The research examines long term trends in investment change by disaggregating into ten property forms rather than the usual three land use sectors. It then assesses to what extent investment patterns can be explained in terms of portfolio theory, short term net returns of individual sectors or driven by the supply of real estate assets. It concludes that the supply of real assets is an overlooked explanation.  相似文献   
68.
Soil water and nutrients are critical drivers of crop production for smallholders of southern Africa. A three-year study was conducted to assess the effect of integrating single and double ploughing, ripping and planting basins with nitrogen fertilizer (0, 10 and 20?kg?N?ha–1) on soil water dynamics and maize (Zea mays L.) yields. The experimental design was factorial with four tillage methods and three nitrogen levels as treatment factors. The study was conducted under semi-arid conditions of Zimbabwe. Tillage methods had similar soil water patterns in the profile and no tillage?×?N interaction effects were observed on soil water dynamics. Soil water penetrated deeper into the profile under ripper and basin methods than conventionally ploughed treatments. Nitrogen increased maize yields (14–96%) and rainwater-use efficiency (20–92%) regardless of tillage methods and growing season quality. However, more studies are required to explore complementary techniques that can improve rainwater capture and prolong soil water storage, and improve soil fertility.  相似文献   
69.
Promotional competitions remain underresearched with only limited conceptualization of campaign design (framing) options evident. Our research addresses the following questions: What are the specific framing options available to campaign planners? What framing strategies should decision-makers apply to optimize campaign performance against promotional aims and objectives? We analyze a sample of promotional competition campaigns in the Australian market to identify the range of specific framing options. We present a taxonomy of Action, Entry, and Prize choices, integrating the key promotional aims of economic, informational, and affective influence. Academic and practitioner implications are discussed and a future research agenda is proposed.  相似文献   
70.
In the second of the two articles, the authors reflect on and extend their earlier work by describing recent trends in water privatization, drawing important lessons from cases where privatization efforts have failed, offering suggestions about the way privatized firms can be successfully monitored, and addressing the popular argument that “fairness” demands that water be distributed by public firms at a zero (or heavily subsidized) price.  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