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   9093篇
  免费   648篇
  国内免费   196篇
财政金融   863篇
工业经济   390篇
计划管理   1783篇
经济学   2025篇
综合类   1679篇
运输经济   42篇
旅游经济   182篇
贸易经济   1263篇
农业经济   493篇
经济概况   1216篇
信息产业经济   1篇
  2024年   32篇
  2023年   229篇
  2022年   278篇
  2021年   330篇
  2020年   391篇
  2019年   259篇
  2018年   233篇
  2017年   267篇
  2016年   277篇
  2015年   350篇
  2014年   566篇
  2013年   733篇
  2012年   790篇
  2011年   936篇
  2010年   667篇
  2009年   602篇
  2008年   687篇
  2007年   604篇
  2006年   502篇
  2005年   362篇
  2004年   233篇
  2003年   162篇
  2002年   113篇
  2001年   87篇
  2000年   60篇
  1999年   42篇
  1998年   27篇
  1997年   26篇
  1996年   22篇
  1995年   13篇
  1994年   8篇
  1993年   5篇
  1992年   5篇
  1991年   3篇
  1990年   3篇
  1989年   6篇
  1988年   2篇
  1987年   2篇
  1986年   1篇
  1985年   1篇
  1984年   3篇
  1983年   6篇
  1982年   6篇
  1981年   5篇
  1980年   1篇
排序方式: 共有9937条查询结果,搜索用时 15 毫秒
61.
[目的]农村劳动力非农转移影响农户农业生产方式变迁,土地质量差异造成的生产差异会随着农村劳动力非农转移造成的人力投入减少而更加显现。针对农户的市场经济行为,文章从理论及实证角度探讨农户农业劳动投入减少时农户生产决策的变化,并根据实证结果进一步探讨我国农业种植结构的变化趋势,为相关政策的制定提供决策参考。[方法]该文运用多元回归模型,从土地资源异质性的视角分析了劳动力非农就业后在不同地势耕地的农业生产决策变化。[结果]劳动力非农就业明显影响了农户种植决策,在质量较高的平地上,农户的生产决策是种植机械化生产使用高的粮食作物来减少劳动力投入下降,在质量较差的山坡地上,农户的生产决策是降低对山坡地的使用强度来解决劳动力投入不足问题,具体表现方式是降低粮食种植面积以及抛荒方式来分配家庭农业劳动投入。[结论]不同地势耕地利用强度将会出现不同变化,平原以及交通便利地区,可以通过机械来替代人力投入,交通较为不发达的山区丘陵地区,需要通过加大农业基础设施建设等来解决山区丘陵地区的抛荒问题。政策支持方面,鼓励中低产田提高产品产量与提升降本技术,保障与维护国家粮食安全。  相似文献   
62.
We analyze whether product market advertising has a spillover effect on stock price synchronicity by transmitting firm-specific information to the capital market and attracting more investor attention. Using a sample of Chinese listed firms from 2009 to 2017, we find that firms with greater advertising expenditures have lower stock price synchronicity. The results are robust after we address endogeneity concerns. In accord with our hypothesis that product market advertising increases the amount of firm-level information capitalized into stock prices through the information channel, we find that the impact of advertising on synchronicity is more pronounced for firms with a higher degree of information asymmetry and firms in the consumer-product industry. Further tests show that product market advertising enhances the ability of current period returns to reflect future earnings, and thus rules out that the negative relationship between advertising and synchronicity is driven by noise trading. Our results imply that product market advertising plays an informative role and improves information efficiency in a capital market.  相似文献   
63.
As per ELM, consumers' motivation and ability influence the route through which they process new information. A higher magnitude of these two factors leads to systematic information processing whereas a lower level leads to peripheral information processing. This research manipulated consumers' motivation by varying the contextual cues like bundle partner's brand image and functional relationship between the items whereas their ability was manipulated by alcohol administration to test its impact on the quality perception of a new brand of alcoholic beverage and the purchase intention of the bundle. A lower magnitude of motivation and ability increases the chances of adopting a categorisation approach to evaluate the new brand, and subsequently, the entire bundle. Therefore, a bundle's contextual cues dictate the evaluation of the new brand. Additionally, the alcohol priming effect leads to a greater propensity to try new brands of alcoholic beverages even if their quality is perceived to be inferior.  相似文献   
64.
硅酸铁锂是一种锂离子电子的正极材料,由于其晶胞在理论上可允许可逆脱嵌两个锂原子,使得其理论比容量有巨大的提升空间,加上原料易得、无污染及成本低的优势,受到了人们的重视。正极材料掺杂被认为是改善其导电性能的有效途径。论文通过运用基于第一性原理方法的计算机仿真技术,对铬掺杂硅酸铁锂的结构和导电性能的影响进行了计算机仿真研究,结果表明未掺杂的硅酸铁锂其带隙快读为2.44eV,掺杂铬之后硅酸铁锂带隙减小为2.31eV,表明铬掺杂可提高硅酸铁锂的导电性能。  相似文献   
65.
石璐珊  贾辉 《科技和产业》2020,20(3):108-115
产业集群能提高企业、区域和国家竞争力。当前以产业创新集群为代表的新一轮产业集群正在各地兴起。通过行业融合、知识外溢和集体行动,产业创新集群促进相关企业和支持性机构紧密互动而加速创新。医疗器械产业科技含量高,创新性强,是当前少数几个涉及学科最多的产业之一。以医疗器械产业为研究对象,从集群和区域创新发展的要义出发,挑选宁波地区的医疗器械行业,测算其行业集中度和产业集群效应,提出提升医疗器械行业集群度,激发产业创新集群活力的对策建议。  相似文献   
66.
This paper aims to investigate the crisis linkage and transmission channels within the housing, stock, interest rate and the currency markets in the U.S. and China in the past decade since the 2008 Subprime Mortgage Crisis. Two hybrid models, namely the SWARCH-EVT-Copula and the Bivariate SWARCH-EVT models, are proposed and applied in order to take into account (A) the high/low volatility regimes, (B) the interdependence structure inherited from the joint tail behaviours, as well as, (C) the risk spillover dynamics among financial sectors during market turmoils. We empirically show that the housing and stock markets share the strongest linkage and play central roles in the spreading of shocks. With a highly integrated system, the American financial sectors are under greater exposure to risk contagion and systemic risk during crises than the Chinese markets. Nevertheless, the exchange rate risk of Renminbi remains at an intensive level since its “crawl-like arrangement” and leads to increasing co-movements in the stock and interest rate markets since 2014.  相似文献   
67.
岳媛媛 《科技和产业》2020,20(10):111-115
以制造业上市公司为样本,探讨社会资本能否抑制僵尸企业对健康企业创新的挤出效应。结果显示:僵尸企业每增加1%,健康企业的发明专利数降低0.41%。僵尸企业的创新挤出效应大部分由非国有企业承担,国有企业的创新并未受到影响。健康企业通过积累不同类型的社会资本来抑制僵尸企业对其创新造成的挤出效应。非国有健康企业的连结型社会资本对创新挤出效应的抑制作用最强,结合型社会资本的作用次之,桥接型社会资本的作用最小。  相似文献   
68.
A strand of the literature documents no effects or even positive effects of a higher minimum wage on employment. This evidence is frequently linked to the existence of monopsonistic labor markets or search frictions. However, empirical studies show that these findings could be related to a low short‐term minimum wage–employment elasticity in a competitive labor market. We show that mixed theoretical employment effects of a minimum wage policy can be predicted in the short term in assignment economies with price‐taker agents and no search frictions.  相似文献   
69.
We exploit a regression discontinuity design to provide causal evidence of the relative age effect (RAE) on a long-run adult age outcome: Political selection. We find strong evidence of the RAE in politics in Finland. However, the effect is heterogeneous: We find that male candidates born early in the calendar year have a significantly higher probability of getting elected to the parliament but no similar RAE applies to female candidates nor to municipal elections. Moreover, this effect only takes place in the most competitive parliamentary districts and is present only for some parties. We also find that in all the groups where the RAE does not exist, early-born candidates are under-represented suggesting attrition of talent in the candidate placement. Overall, our results show that seemingly artificial cutoffs imposed by the government have persistent consequences even on the selection to the highest positions of power within a society.  相似文献   
70.
Agricultural commodity markets in developing countries often operate in a constrained environment of prohibitive transaction costs. Consequently, smallholder farmers are only partly integrated into these markets, a situation that keeps them in a lower level of development equilibrium (poverty trap). Although cooperative institutional alternatives such as Farmers’ Organizations (FOs) may reduce transaction costs and revitalize agricultural production and commercialization, they rarely have been successful in fully delivering on these promises. Against this backdrop, the World Food Programmed (WFP) has recently implemented a multi-year and multi-country pilot to increase smallholder participation in commodity markets. The projects involved investing in physical and human capacities of Farmer Organizations (FOs) to aggregate commodities and add value, as well as locally purchasing food aid from the same. The combination of interventions was expected to increase the relative price of agricultural products, particularly staple crops. In this study, using Ethiopian panel survey data, we estimated the causal income and investment effects of the Ethiopian P4P intervention among smallholders. Using an entropy balancing (EB) model and semi-parametric difference-in-difference (DID) model, we show that the P4P intervention has increased per capita consumption by smallholders. Our additional analysis confirms that this effect is heterogeneous owing to elite capture within Farmer Organizations. We also find evidence of increased food consumption scores, increased investments in child schooling, and increased asset holding among program-participating smallholders relative to comparison farmers. Policy implications are discussed.  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