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   28985篇
  免费   1271篇
  国内免费   521篇
财政金融   2642篇
工业经济   1534篇
计划管理   6567篇
经济学   5709篇
综合类   3297篇
运输经济   381篇
旅游经济   539篇
贸易经济   3738篇
农业经济   3061篇
经济概况   3308篇
信息产业经济   1篇
  2024年   104篇
  2023年   583篇
  2022年   558篇
  2021年   858篇
  2020年   1115篇
  2019年   831篇
  2018年   743篇
  2017年   995篇
  2016年   962篇
  2015年   938篇
  2014年   1980篇
  2013年   2439篇
  2012年   2259篇
  2011年   2628篇
  2010年   1973篇
  2009年   1795篇
  2008年   1985篇
  2007年   1823篇
  2006年   1560篇
  2005年   1203篇
  2004年   840篇
  2003年   600篇
  2002年   424篇
  2001年   369篇
  2000年   305篇
  1999年   192篇
  1998年   144篇
  1997年   103篇
  1996年   113篇
  1995年   59篇
  1994年   66篇
  1993年   40篇
  1992年   49篇
  1991年   33篇
  1990年   8篇
  1989年   10篇
  1988年   11篇
  1987年   9篇
  1986年   13篇
  1985年   24篇
  1984年   18篇
  1983年   5篇
  1982年   5篇
  1981年   4篇
  1980年   1篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
971.
This paper contains an exploratory analysis of the business model innovations (BMIs) that firms in cultural and creative industries (CCIs) undertake along their life-cycle. Despite the role that creative and cultural and creative firms (CCFs) have in the economic development of industrialised countries, they tend to remain small and often fail due to industry-specific constraints and tensions, such as the lack of managerial capabilities and complexity in nurturing value chain relationships. However, there has been relatively limited scholarly interest into the specific conditions and processes that enabled CCFs to overcome these liabilities, and in particular into the identification of the business models they have adopted along their life-cycle. In this paper, this issue is analysed by using the concept of BMI, which sheds light on how the reconfiguration of the activity system through which a CCF creates, delivers and captures value enables the exploitation of entrepreneurial opportunities over time. This paper builds on an in-depth historical study of three leading firms operating in the mobile gaming industry, namely Rovio, Zynga and King Digital Entertainment. Three main results emerge from this study. First, in the ramp-up phase of their life-cycle, CCFs organize their resource architecture to build a strong and recognized reputation. Second, in the development phase, BMI is used to leverage new distribution paradigms. Finally, in the maturity phase, firms dedicate resources to innovate their product portfolios by providing platforms that support the development and testing of new creative ideas and solutions. Findings and implications are then discussed.  相似文献   
972.
We develop an algorithm that forecasts cascading events, by employing a Green’s function scheme on the basis of the self-exciting point process model. This method is applied to open data of 10 types of crimes happened in Chicago. It shows a good prediction accuracy superior to or comparable to the standard methods which are the expectation–maximization method and prospective hotspot maps method. We find a cascade influence of the crimes that has a long-time, logarithmic tail; this result is consistent with an earlier study on burglaries. This long-tail feature cannot be reproduced by the other standard methods. In addition, a merit of the Green’s function method is the low computational cost in the case of high density of events and/or large amount of the training data.  相似文献   
973.
随着国家发展西部地区的力度不断加大,贵州省作为西部地区省份也乘着这股力度不断在各方面完善自己,G市作为贵州省的主要城市之一近几年在经济、政治等方面都有显著的提高。物流的发展在一定程度上可以带动一个地区产业的发展,物流的构架在一定程度上可以反映出一个地区产业的构架。通过对G市物流运营现状的分析,发现G市的产业结构的特性,然后,通过分析建立符合G市物流发展的预测模型,最后结合模型和分析对G市物流发展提出合理化建议。  相似文献   
974.
In line with Kang and Herr's work (2006), this research questions the ELM's contention that celebrity credibility serves foremost as a peripheral element in a persuasive communication context. Nevertheless, in a different light to the Kang and Herr's ‘either-central-or-peripheral-role’ of a source characteristic, this research advances that celebrity credibility plays concomitantly central and peripheral roles in a persuasive message context depending on product involvement and brand-purchase motive. Particularly, this research uses the notions of ‘source internalization’ and ‘source identification’ (Kelman, 1961) to theorize that source credibility can have a concomitant dual role (peripheral and central) in a persuasion context. More precisely, this research investigates the interactive effects of source identification and internalization with product involvement as well as brand-purchase motives on consumers' attitudes and intentions. Source internalization is predicted to have persuasive effects in the contexts of high-involvement as well as informational products. Source identification is predicted to have persuasive effects in the context of low-involvement as well as transformational products. The findings of two experiments show that celebrity credibility acts through only a single route (i.e., only internalization has persuasive effects) uniformly across different product involvement levels and brand-purchase motive types. We interpret these results with the lens of the ‘match-up’ hypothesis (Kamins, 1990).  相似文献   
975.
长江经济带城镇化的发展促进了工业的进步,而工业发展的同时也伴随着工业废水排放的增加及对水环境的破坏。通过建立城镇化与工业废水排放之间的STIRPAT模型,分析长江经济带城镇化对工业废水排放的具体影响。结果表明:长江三角洲经济区及长江经济带整体城镇化水平与工业废水排放之间存在着倒N型关系,长江上游经济区和长江中游经济区的城镇化水平与工业废水排放之间存在倒U型曲线关系;经济发展水平和人口规模对工业废水排放的影响存在地区差异;长江经济带及各区域技术水平和产业结构对工业废水排放存在显著的正向影响。据此,在推动新型城镇化建设中,应采取政策扶持、转变经济发展方式、提高公众环保意识、调整产业结构及加速技术创新等措施,以期减少工业废水排放。  相似文献   
976.
Replacement brood cows are among the most significant investments for cow-calf operations, thus crucial to profitability. Many cow-calf producers find it cost effective to purchase replacements from a reliable replacement heifer seller, though by doing so they increase risk of reproductive inefficiency due to unknown characteristics of the heifers. When important information about a product is missing to buyers, a seller can build a reputation over time that acts as signal for quality. Previous work has explored reputation effects in feeder cattle markets, but to our knowledge we are the first to explore reputation effects in bred replacement cattle markets. Using data from an annual replacement heifer sale, we analyze the values of heifer characteristics and test for premiums from reputation development. After controlling for reproductive practices, breed, and other characteristics, we find reputation does not play the role that Shapiro theorized. In this sale, the lot order is strategically chosen and may indicate bred heifer quality to buyers, replacing the need for reputation as a signal. This study highlights the importance of quality signals and regional preferences in bred replacement cattle marketing and lays the empirical groundwork for future studies to test Shapiro's theory.  相似文献   
977.
为了解决航空发动机双通道电子控制器(EEC)两个通道均发生故障时如何评估通道健康度,从而选择主控通道的问题,论文提出了基于逆模型计算发动机推力敏感度的方法,量化不同信号故障对发动机推力的影响程度,依据推力敏感度来评估双通道健康度,协助主控通道选择,最终提高系统的安全性。  相似文献   
978.
This paper examined climate change adaptation strategies in fish farming and the effect of such methods on the profit of fish farmers in the Niger Delta region of Nigeria, Africa’s most populous country. Using cross‐sectional data obtained from 420 fish farmers from the region and applying multivariate probit and instrumental variable regressions, the study found that fish farmers have adopted a broad range of strategies to address climate risk and that these have significantly increased farmers’ profit. Our findings indicated important relationships between certain farm, socio‐economic and institutional characteristics and the adaptation actions. The study provides useful insight into factors that potentially encourage the adoption of livelihood‐enhancing climate risk adaptation strategies by fish farmers in the Niger Delta region and similar contexts.  相似文献   
979.
论文调查分析了近年来热度较高的跨境社交媒体平台以及相关使用数据,利用相关性分析方法分析了多个平台的数据,在此过程中发现了各平台间具有相当高的互惠性,并运用互惠比例和推广方式适配度模型完成了对跨境社交平台的运行模式以及推广方式的对比分析,最终研究得出跨境社交媒体平台的产品推广模式。  相似文献   
980.
The COVID-19 recession that started in March 2020 led to an unprecedented decline in economic activity across the globe. To fight this recession, policy makers in central banks engaged in expansionary monetary policy. This paper asks whether the measures adopted by the US Federal Reserve (Fed) have been effective in boosting real activity and calming financial markets. To measure these effects at high frequencies, we propose a novel mixed frequency vector autoregressive (MF-VAR) model. This model allows us to combine weekly and monthly information within a unified framework. Our model combines a set of macroeconomic aggregates such as industrial production, unemployment rates, and inflation with high-frequency information from financial markets such as stock prices, interest rate spreads, and weekly information on the Fed's balance sheet size. The latter set of high-frequency time series is used to dynamically interpolate the monthly time series to obtain weekly macroeconomic measures. We use this setup to simulate counterfactuals in absence of monetary stimulus. The results show that the monetary expansion caused higher output growth and stock market returns, more favorable long-term financing conditions and a depreciation of the US dollar compared with a no-policy benchmark scenario.  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