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   6440篇
  免费   289篇
  国内免费   84篇
财政金融   526篇
工业经济   585篇
计划管理   2537篇
经济学   710篇
综合类   505篇
运输经济   95篇
旅游经济   100篇
贸易经济   907篇
农业经济   327篇
经济概况   519篇
信息产业经济   2篇
  2024年   23篇
  2023年   83篇
  2022年   126篇
  2021年   164篇
  2020年   192篇
  2019年   167篇
  2018年   129篇
  2017年   158篇
  2016年   160篇
  2015年   242篇
  2014年   519篇
  2013年   646篇
  2012年   527篇
  2011年   680篇
  2010年   465篇
  2009年   359篇
  2008年   434篇
  2007年   373篇
  2006年   318篇
  2005年   245篇
  2004年   165篇
  2003年   147篇
  2002年   107篇
  2001年   79篇
  2000年   63篇
  1999年   49篇
  1998年   32篇
  1997年   40篇
  1996年   35篇
  1995年   21篇
  1994年   14篇
  1993年   12篇
  1992年   7篇
  1991年   11篇
  1990年   2篇
  1989年   4篇
  1988年   2篇
  1986年   3篇
  1985年   5篇
  1984年   2篇
  1983年   1篇
  1980年   1篇
  1978年   1篇
排序方式: 共有6813条查询结果,搜索用时 145 毫秒
1.
In theory, learning from past mistakes should result in adapted and improved development policy. However policy learning can be difficult to achieve, and the link between learning and policy change is neither direct nor immediate. In this study we look at learning in agro-industrial policy in Ghana, by tracing the interest in sugar production and tomato processing over six decades. Specifically we ask why four failed factories established in the early 1960s have continued to play central roles in both policy and public discourse. Using policy documents, academic material, and the popular press, we show that Ghana’s policy focus on sugar production and tomato processing has endured, despite the fact that the factories were misconceived, poorly sited, ill-equipped and poorly managed. Indeed, the political ideas that underpinned the establishment of these factories in the early days of independence can be seen in the current One District, One Factory policy. We suggest that it is their symbolic and political value, not their economic value, which keeps the discussion around these factories alive. Even when shut down, they are a physical manifestation of historic commitments by the state, and as such they guarantee the attention of politicians, and hold out hope of a next re-launch. Unfortunately as long as the factories continue to be incorporated into each new generation of agro-industrial policy, it is difficult for any alternatives to gain traction. This analysis highlights the very long overhang of bad decisions, particularly when they are associated with physical infrastructure. Learning from past mistakes will only happen if the short-term political cost of turning policy learning into policy action can be overcome.  相似文献   
2.
ABSTRACT

This paper aims to explore the conceptual potential of the Deleuzian notion of the encounter in order to better understand the genealogy of opportunities. We adopt a processual perspective of opportunities. In order to translate this notion to the domain of entrepreneurship, we analysed and interpreted Jean-Marc Vallée’s Dallas Buyers Club. This film follows the creation of the first club in the United States that illegally allowed HIV-positive people to supply themselves with foreign antiretroviral drugs from Mexico or Japan. The article highlights encounters in this process that disturb the entrepreneur’s belief systems and allow him or her to be open to potential opportunity. It finally explores how the encounter may improve our understanding of the political becoming of opportunities within the entrepreneurial process.  相似文献   
3.
《Journal of Retailing》2022,98(2):277-293
This research examines how consumers’ intentions to purchase food change depending on the visualisation mode (3D vs. AR) and product format (served vs. packaged). In three studies, we demonstrate that mental simulation of eating experiences (process and outcome) mediate these effects. Study 1 shows that AR visualisation of a served food improves simulation of the eating process over 3D visualisation, with a positive effect on purchase intention. Study 2 reveals that 3D visualisation improves purchase intention for packaged products (high instrumental properties) over served products (low instrumental properties) while the opposite is true for AR visualisation. In addition, interactivity and immersion mediate the effects of 3D (vs. AR) on mental simulation of the eating process for packaged products. Study 3 extends these results by showing that 3D increases purchase intention by eliciting mental simulation of the eating outcome, when the food is visible due to transparent (vs. opaque) packaging (displaying both sensory and instrumental properties), but that no such differences emerge for AR. This research highlights the importance of using different visualisation modes to promote food depending on the product format. The findings have important implications for both offline and online retailers.  相似文献   
4.
In the context of personal income tax (PIT) reform in China in 2018, this paper examines some of the major issues of concern regarding the reform and income distribution. Using the China Personal Income Tax Micro‐simulation model, the paper compares the differences between the 2011 and 2018 PIT systems, and finds that residents relying on different income sources may face a large degree of real tax rate change. Once the tax system is altered to PIT 2018, the coverage of PIT for wage earners will decrease from 46.9 to 23.4 percent, the income redistributive effect will drop from 1.95 to 1.22 percent and the PIT's role in fiscal revenue will also be negatively affected. Nevertheless, if individual income continues to grow, the share of PIT in fiscal revenue is expected to return to the 2018 level in 2022, but its income redistribution function is difficult to recover in the short term. The paper finds that the effect of PIT on income distribution depends on the tax structure. Gradual transition to an “entirely comprehensive” tax system when conditions are appropriate will achieve better income redistribution results at a lower average tax rate.  相似文献   
5.
河南省农业生态旅游产业可持续发展评价研究   总被引:1,自引:0,他引:1  
[目的]河南农业生态旅游作为一种可持续发展的旅游形式,为河南的经济发展作为了重要贡献。对河南农业生态旅游产业可持续发展进行评价研究,是促进农业生态旅游可持续健康发展的重要保证。[方法]文章通过实地调研构建河南农业生态旅游产业可持续发展评价指标体系,运用层次分析法,确定指标权重,结合专家评分法,对各项评价指标打分,并计算河南农业生态旅游产业可持续发展的综合得分,结合农业生态旅游产业可持续发展评价标准,得出目前河南农业生态旅游产业可持续发展水平。[结果]河南农业生态旅游产业可持续发展评价得分为72.45,处于基本可持续发展阶段,并对当前河南农业生态旅游发展现状和存在的农业生态旅游意识淡薄、旅游产品特色不明显、缺少政府资金扶持和缺乏经营管理人才等问题进行了分析。[结论]基于上述问题,提出了提高环保意识、走可持续发展之路;开发特色原生态旅游产品;加强政府支持和引导;加强专业培训,打造专业队伍等对策。  相似文献   
6.
以长春市为研究对象,基于未来经济处于新常态的发展态势,构建包含水资源、社会、经济、生态环境4个子系统的评价指标体系,并确定各指标的评价等级标准;基于模糊数学理论以及层次分析法构建包括目标层、准则层、指标层的3层模糊综合评价模型,以2015年为现状水平年,应用模型对长春市水资源开发利用潜力进行综合评价。结果表明:长春市水资源开发利用程度处于中等偏上水平,各辖区水资源开发利用规模不平衡,可通过产业结构调整提高全市用水效率,为经济持续增长提供保障。  相似文献   
7.
The credit risk contagion of Internet peer-to-peer (P2P) lending platforms is an important part of Internet financial risk management and supervision. This study analyzes the contagion path of credit risk in Internet P2P lending. Based on complex network theory and the theory of infectious disease dynamics, the characteristics of Internet P2P lending development are combined to construct a SEIR model of credit risk transmission among Internet P2P lending platforms with time lag, and the robustness of the model is analyzed and proven. The influence of platform correlations, the susceptible immune rate, the platform elimination rate, contagion latency, the saturation coefficient, and the susceptibility input rate on credit risk contagion behavior among Internet P2P lending platforms is analyzed, using the equilibrium point and threshold value. The impact of each variable is analyzed by simulation. Corresponding countermeasures and suggestions are proposed to prevent and control credit risk contagion among these platforms.  相似文献   
8.
ABSTRACT

We present a group dynamics model that shows knowledge integration as a process occurring over time. As each individual in the group contact others, his own knowledge changes, and over time the collective knowledge is obtained. This allows modeling knowledge diffusion in a social network and while the models presented in this paper are not competitive in that area, they approach the problem from previously unconsidered direction. We test the behavior of the model in a multi-agent simulation and we test a simple advertisement campaign in a social network. We provide discussion of elements needed for making model more competitive.  相似文献   
9.
[目的]开展农业干旱危险性评价与区划研究,为辽宁省西北地区农业防旱抗灾工作提供科学依据。[方法]文章根据联合国国际减灾战略署(ISDR)对农业干旱危险性的定义,分析了构成研究区作物干旱危险性的致灾因子和孕灾环境因子,采用层次分析法确定了各因子的权重,构建了研究区农业干旱危险性评价指标和模型。以2009年为例,通过利用降雨、土壤、农业生产类型及地形等数据计算了辽西北地区农业干旱危险性评价指数,利用自然间断点法分级干旱危险性评价指数,并借助GIS技术,绘制研究区农业干旱危险性等级区划图。[结果] 2009年作物生长期间研究区农业干旱危险性由高到低排列为:朝阳市葫芦岛市锦州市阜新市铁岭市沈阳市。[结论]辽西北地区农业干旱危险性等级区的划分,能够帮助政府管理部门为面临干旱威胁不同的区域建立适当的防灾方法和有效的应急预案。  相似文献   
10.
A play-the-winner-type urn design with reduced variability   总被引:1,自引:0,他引:1  
We propose a new adaptive allocation rule, the drop-the-loser, that randomizes subjects in the course of a trial comparing treatments with dichotomous outcomes. The rule tends to assign more patients to better treatments with the same limiting proportion as the randomized play-the-winner rule. The new design has significantly less variable allocation proportion than the randomized play-the-winner rule. Decrease in variability translates into a gain in statistical power. For some values of success probabilities the drop-the-loser rule has a double advantage over conventional equal allocation in that it has better power and assigns more subjects to the better treatment. Acknowledgments. I thank Stephen Durham, the associate editor, and the referees for their helpful suggestions.  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