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   27516篇
  免费   594篇
  国内免费   3篇
财政金融   3616篇
工业经济   2046篇
计划管理   5915篇
经济学   4971篇
综合类   2247篇
运输经济   175篇
旅游经济   131篇
贸易经济   3071篇
农业经济   1639篇
经济概况   4235篇
信息产业经济   5篇
邮电经济   62篇
  2024年   26篇
  2023年   247篇
  2022年   466篇
  2021年   653篇
  2020年   649篇
  2019年   437篇
  2018年   347篇
  2017年   706篇
  2016年   504篇
  2015年   620篇
  2014年   836篇
  2013年   1416篇
  2012年   2144篇
  2011年   3598篇
  2010年   3048篇
  2009年   1905篇
  2008年   1998篇
  2007年   1894篇
  2006年   2086篇
  2005年   1836篇
  2004年   533篇
  2003年   485篇
  2002年   464篇
  2001年   440篇
  2000年   226篇
  1999年   116篇
  1998年   90篇
  1997年   73篇
  1996年   54篇
  1995年   28篇
  1994年   30篇
  1993年   30篇
  1992年   33篇
  1991年   27篇
  1990年   20篇
  1989年   11篇
  1988年   12篇
  1987年   5篇
  1985年   1篇
  1984年   13篇
  1983年   2篇
  1980年   2篇
  1978年   1篇
  1900年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
[目的]以高分1号(GF-1)融合2m卫星遥感影像为基础数据源,结合土地利用现状数据、高分多源遥感影像和地面样方等数据,对冬小麦分类提取中存在的面积误差问题进行研究和分析。[方法]文章以河南省永城市为研究区,在冬小麦提取结果聚类处理基础上,基于线性地物缓冲区数据,采用GIS空间运算实现线性地物面积扣除,接着分析了样方数据和土地利用现状数据再扣除零星地物面积比例上的差异,并采用样方零星地物平均扣除系数对全市各乡镇耕地与非耕地中冬小麦提取面积进行了相关统计和误差分析。[结果]永城市冬小麦最终解译面积11. 29万hm~2,其中线性地物和零星地物扣除面积分别为6 613. 08hm~2和3 875. 22hm~2,占研究区冬小麦解译面积的5. 86%和3. 32%,与统计上报数据相比,其处理前后误差由14. 12%降低至4. 41%,有效地提高冬小麦提取面积精度。[结论]误差来源分析与修正对冬小麦解译面积核算精度具有重要影响,该研究为县级区域尺度下冬小麦面积提取核算提供了思路和借鉴。  相似文献   
12.
从效率差异视角构建国家创新影响力评价方法,揭示“一带一路”沿线国家创新要素流动倾向性以促进交流合作。运用DEA模型测算各国创新效率,根据DEA原理识别国家间的认可关系,构建创新网络并用节点特征向量中心度表示各国创新影响力,分析创新影响力类型、创新网络特征及创新投入冗余率与产出不足率。结果发现,各国创新效率存在显著差距;各国分别处于创新网络中心、核心和边缘位置,国家创新影响力依次递减;按照创新要素相对强度,沿线国家可分为6种创新类型;最后,提出沿线国家间开展创新交流与合作的必要性和途径。  相似文献   
13.
Drawing upon token theory and critical mass theory, this study examines whether all female directors are equally considered as tokens. We argue that inside female directors are less likely than outside female directors to be considered as tokens because they are more powerful and influential. Using a 10-year sample of Chinese publicly listed firms on the Shanghai or Shenzhen Stock Exchanges from 2008 to 2017, we find that even one inside female director can make a significant contribution to corporate social responsibility (CSR), while outside female directors do not have a positive effect on CSR until their number reaches the critical mass (i.e., three). The results suggest that the predictions of token theory and critical mass theory vary across female director types. These findings contribute to the current literature by integrating female director typology with their numerical representation to explain their token status.  相似文献   
14.
产能合作是当前和未来促进中哈两国经济协同发展的核心方式,江淮汽车成功进入哈萨克斯坦,对于推进两国制造业产能合作具有重要意义.充分利用国家政策、对接哈萨克斯坦汽车工业发展战略和市场需求、选择恰当国际市场进入模式和营销策略、培植核心竞争力以及积极应对哈萨克斯坦市场的激烈竞争是江淮汽车成功进入哈萨克斯坦市场的关键因素.我国企业应有效对接哈萨克斯坦经济战略,积极参与中哈产能合作;精准目标市场定位,优化产品结构;选择合适的市场进入模式,积极开展本地化生产;不断提升企业的核心竞争力.  相似文献   
15.
We investigate how overconfident CEOs and CFOs may interact to influence firms’ tax avoidance. We adopt an equity measure to capture overconfident CEOs and CFOs and utilize multiple measures to identify companies’ tax-avoidance activities. We document that CFOs, as CEOs’ business partners, play an important role in facilitating and executing overconfident CEOs’ decisions in regard to tax avoidance. Specifically, we find that companies are more likely to engage in tax-avoidance activities when they have both overconfident CEOs and overconfident CFOs, compared with companies that have other combinations of CEO/CFO overconfidence (e.g., an overconfident CEO with a non-overconfident CFO), which is consistent with the False Consensus Effect Theory. Our study helps investors, regulators, and policymakers understand companies’ decision-making processes with regard to tax avoidance.  相似文献   
16.
Extant scholarship treats national policies concerning labour rights as a function of economic factors and yet neglects influences of policies among economically competing states. Relying on the policy interdependence theory, this study argues that labour rights policy in a state is dependent on its economic competitors’ labour policy decisions. It specifically maintains that the intensifying competition for foreign direct investment and exports as well as against imports channels negative externalities of deteriorating labour protection in competing states which drives expansive downward policy mimicking and leads to a global decline in labour rights – a race to the bottom. Utilising spatial econometric technique to analyse a new data on labour rights for the period 1994–2009, it finds that labour rights practices are interdependent among economic competitors and experience global deteriorations; whereas labour rights laws remain largely independent due to high policy and reputational costs of lowering them and show more fluctuations.  相似文献   
17.
Studies on the determinants of entrepreneurship emphasize that challenged adults tend to become entrepreneurs. However, research has not addressed the childhood origins surrounding the propensity for entrepreneurship. This article links childhood adversity to the propensity of individuals to become migrant entrepreneurs later in life. We test hypotheses derived from this theory in the context of whether, and when, children who survived the Great Chinese Famine of 1959–1961 became migrant entrepreneurs. Results strongly indicate that those who survived greater hardship during the Famine are more likely to become entrepreneurs, especially when they were younger during the famine years. We also find that being younger at the time of migration increased the likelihood of becoming entrepreneurs in their new locale. Overall, this study casts light on why, how and when childhood adversity shapes the propensity for entrepreneurship.  相似文献   
18.
We price an American floating strike lookback option under the Black–Scholes model with a hypothetic static hedging portfolio (HSHP) composed of nontradable European options. Our approach is more efficient than the tree methods because recalculating the option prices is much quicker. Applying put–call duality to an HSHP yields a tradable semistatic hedging portfolio (SSHP). Numerical results indicate that an SSHP has better hedging performance than a delta-hedged portfolio. Finally, we investigate the model risk for SSHP under a stochastic volatility assumption and find that the model risk is related to the correlation between asset price and volatility.  相似文献   
19.
This article studies how aid for trade (AfT) affects the quality of recipient countries’ exports. It shows that the quality effect is most discernible for AfT for assistance in trade policy: a 50% increase in the value of AfT received in this category is associated with a 0.5–1% increase in the quality of exports to the donor and other OECD countries. On average, the actual AfT received for assistance in trade policy leads to a 2% upgrade of the recipient country in the quality ladder of all developing countries. Around half of this quality effect is driven by the quality improvement of continued products in continued markets (intensive margin), and the other half by the quality upgrading of new products in continued markets and existing products in new markets (extensive margin).  相似文献   
20.
在全面实施创新驱动发展战略的时代背景下,揭示中国高端装备制造业自主技术创新效率稳定性,测度相关因素的影响强度与方向,对揭示中国高端装备制造业自主技术创新规律,制定其发展策略具有重要指导意义。聚焦中国高端装备制造业自主技术创新效率稳定性及影响因素,采用DEA-Malmquist指数方法和Tobit回归模型进行实证研究,结果表明,中国高端装备制造业自主技术创新效率存在一定波动性,且各细分行业技术创新效率内部稳定性较差,产业自主技术创新效率整体稳定性不高;自主技术创新投入因素和环境影响因素对产业自主技术创新效率的影响具有较高的异质性,其中创新资金投入和人力资源投入对自主技术创新综合效率、纯技术效率及规模效率具有正向影响,而新产品开发投入和企业规模对自主技术创新综合效率、纯技术效率和规模效率的影响具有异质性,政策因素与市场因素分别具有显著和非显著负向影响,外源性创新因素具有显著正向影响,且影响强度较大。在此基础上,提出调整政府对高端装备制造业创新支持模式、加强外源性创新与智力引进等策略建议。  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