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   7269篇
  免费   178篇
  国内免费   22篇
财政金融   878篇
工业经济   518篇
计划管理   1433篇
经济学   1369篇
综合类   779篇
运输经济   39篇
旅游经济   46篇
贸易经济   783篇
农业经济   453篇
经济概况   1147篇
信息产业经济   1篇
邮电经济   23篇
  2024年   9篇
  2023年   56篇
  2022年   144篇
  2021年   219篇
  2020年   197篇
  2019年   139篇
  2018年   92篇
  2017年   162篇
  2016年   154篇
  2015年   204篇
  2014年   278篇
  2013年   352篇
  2012年   609篇
  2011年   827篇
  2010年   750篇
  2009年   513篇
  2008年   598篇
  2007年   479篇
  2006年   503篇
  2005年   478篇
  2004年   124篇
  2003年   137篇
  2002年   136篇
  2001年   108篇
  2000年   59篇
  1999年   27篇
  1998年   23篇
  1997年   18篇
  1996年   13篇
  1995年   10篇
  1994年   5篇
  1993年   12篇
  1992年   11篇
  1991年   7篇
  1990年   3篇
  1989年   4篇
  1988年   3篇
  1984年   4篇
  1981年   2篇
排序方式: 共有7469条查询结果,搜索用时 31 毫秒
191.
This study examines financial analyst coverage for U.S. firms following an increase in foreign product market competition. To capture exogenous shocks to domestic firms' competitive environments, we exploit a quasi‐natural experiment from large import tariff reductions over the 1984 to 2005 period in the manufacturing sector. Using data for the years before and after large tariff reductions, our difference‐in‐differences analysis shows evidence of a significant decrease in analyst coverage for incumbent U.S. firms when they face greater entry threat from foreign competitors. We also find that analysts with less firm‐specific experience and less accurate prior‐period forecasts are more likely to stop following the domestic firm when foreign competition intensifies. Overall, the findings suggest that foreign product market competition from global trade liberalization is an important determinant of financial analysts' coverage decisions.  相似文献   
192.
以150个创业企业为样本,基于创业学习和商业模式创新理论,运用模糊集定性比较分析方法(fsQCA),探究经验学习、认知学习、新颖型商业模式创新和效率型商业模式创新对创新绩效的影响路径及机制。研究发现,存在新颖型商业模式创新等4条创新绩效产出关键路径;相较于效率型商业模式创新,新颖型商业模式创新在关键路径中更容易提高创新绩效;利用QCA方法证实了影响创业企业创新绩效的组态内部各要素之间的替代性。结论丰富了创新绩效产出内部机制,可为创业企业提高创新绩效提供指导和借鉴。  相似文献   
193.
以稻谷粤农丝苗为原材料,置于4种不同储藏模式下,具体如下:(1)15℃储藏240d。(2)30℃储藏240d。(3)以15℃为开端,与30℃交替储藏(60d交替1次)至240d。(4)以30℃为开端,与15℃交替储藏(60d交替1次)至240d。每隔60d检测1次,比较上述4种储藏模式下,稻米蒸煮品质和α-淀粉酶活力的变化趋势。研究结果表明:随着时间的延长和储藏温度的升高,稻米品质下降;在实验时间内,以低温为开端的变温模式的稻米品质要优于以高温为开端的变温模式,但差距逐渐减小。  相似文献   
194.
In the face of state-led land grabs, enterprising Chinese peasants have started a revolution in the ambiguous and insecure rural tenure system by developing an extralegal property system known as the small property right (SPR). Using the SPR, peasants are able to capitalize on their property through the sale of houses built on collectively owned land. Little is known, however, about the specific process behind the development of the SPR by the peasants, or how this extralegal property system functions in terms of securing the use and transfer of property without the backing of law. This article aims to clarify the situation through the lenses of the Endogenous Nature of Institutions and Relational Contract Theory, aiming to understand the socially constructed, endogenous and relational nature of the property rights that make SPR functional. Based on an ethnographic investigation of Beijing's largest SPR housing settlement, we show how enterprising peasants develop long-term relational contracts with urban households for the provision of housing services, secured on the basis of the common interests and symbiosis of the two parties and a reputation system that serves to deter defaults. The discretionary treatment of SPR housing by local states serves as a further motivation for the village and the informal homeowners to preserve a stable property arrangement, with such a specific institutional setting being an exemplar of China's pragmatic state entrepreneurialism.  相似文献   
195.
There have been a number of previous studies that examined the effects of yield- or revenue-based crop insurance products on input use of farmers. However, no study has specifically investigated the input use impacts of a cost-of-production (COP) crop insurance policy, even though this type of crop insurance is the predominant one used in several other countries outside of the United States (such as the Philippines and China). This article aims to theoretically and empirically examine the effect of a COP crop insurance product on farmers’ chemical input use. Our theoretical model suggests that the effect of COP insurance on input use can either be positive or negative, with the resulting impact depending on the strengths of (a) the traditional moral hazard effect of insurance (i.e., an input use decreasing effect); versus (b) the marginal incentives to apply more inputs due to input levels being the main determinant for expected indemnity amounts in this type of insurance (i.e., an input use increasing effect). A survey data set from corn farmers in the Philippines is then used to empirically illustrate how a particular COP insurance product influences input use in a real-life context. In this case, we find that COP insurance increases the use of chemical inputs (e.g., fertilizers and total chemical expenditure), implying that the positive marginal incentive to apply more inputs dominates the negative moral hazard effect.  相似文献   
196.
通过对牛肉酱、红油2种即食油脂类调味品进行微生物检测,将不同比例的吐温80添加到样品前处理的稀释液中,采用浓度为107 CFU·mL-1的标准菌悬液,用常规细菌培养法检测结果。结果表明:选用比例为5%的吐温80对牛肉酱、红油的微生物指标进行检测,检测结果均在107 CFU·mL-1,与空白对照的检测结果在同一数量级上。与常规的稀释液相比,吐温80可使样品均匀分散在稀释液中,且不影响微生物的检测结果,可适用于高油脂类样品的日常微生物检测。  相似文献   
197.
Wen He  Ki Hoon Hong  Eliza Wu 《Abacus》2020,56(4):535-560
We investigate whether investor sentiment affects the relationships between accounting variables and contemporaneous stock returns. Using price-relevant accounting variables identified by Chen and Zhang (2007) and the investor sentiment index constructed by Baker and Wurgler (2006), we find that the value relevance of accounting variables is collectively lower in high sentiment periods than in low sentiment periods. More importantly, earnings yield appears to be more related to contemporaneous stock returns in high sentiment periods, while other accounting variables are more related to stock returns in low sentiment periods. The effect of investor sentiment on the value relevance of accounting information is stronger for firms that are more difficult to value and to arbitrage.  相似文献   
198.
In this paper, we study the excursions of Bessel and Cox–Ingersoll–Ross (CIR) processes with dimensions . We obtain densities for the last passage times and meanders of the processes. Using these results, we prove a variation of the Azéma martingale for the Bessel and CIR processes based on excursion theory. Furthermore, we study their Parisian excursions, and generalize previous results on the Parisian stopping time of Brownian motion to that of the Bessel and CIR processes. We obtain explicit formulas and asymptotic results for the densities of the Parisian stopping times, and develop exact simulation algorithms to sample the Parisian stopping times of Bessel and CIR processes. We introduce a new type of bond, the zero‐coupon Parisian bond. The buyer of such a bond is betting against zero interest rates, while the seller is effectively hedging against a period where interest rates fluctuate around 0. Using our results, we propose two methods for pricing these bonds and provide numerical examples.  相似文献   
199.
使用基于主成分分析和动态因子模型的框架对我国的消费者物价指数进行动态分析。与传统的研究方式不同,研究试图从非价格指标信息中提取隐含的宏观趋势动态因子,并将其投影在价格指数上,求得最优拟合结果。实证分析结果显示从非价格数据中提取的动态因子可以很好地描述价格指数的变化特征。这也为研究者从实体经济运行状态角度研究宏观经济价格指数以及货币政策的传导机制提供了有效的理论和实践依据。  相似文献   
200.
贾凌燕 《物流技术》2015,(4):173-175
以辽宁省某物流公司全面预算管理现状为基础,从预算组织管理、预算编制管理、预算执行、预算考核等方面进行分析与探讨,同时对其全面预算管理存在的问题进行剖析,结合其发展战略制定了相应的完善全面预算管理体系的对策。  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