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   45478篇
  免费   1773篇
  国内免费   586篇
财政金融   3455篇
工业经济   2083篇
计划管理   10995篇
经济学   7659篇
综合类   7349篇
运输经济   416篇
旅游经济   845篇
贸易经济   5512篇
农业经济   3455篇
经济概况   6068篇
  2024年   59篇
  2023年   537篇
  2022年   761篇
  2021年   1281篇
  2020年   1533篇
  2019年   907篇
  2018年   789篇
  2017年   902篇
  2016年   1079篇
  2015年   1319篇
  2014年   3437篇
  2013年   3746篇
  2012年   4075篇
  2011年   4999篇
  2010年   3696篇
  2009年   3032篇
  2008年   3062篇
  2007年   2594篇
  2006年   2449篇
  2005年   1803篇
  2004年   1279篇
  2003年   1086篇
  2002年   778篇
  2001年   768篇
  2000年   531篇
  1999年   316篇
  1998年   150篇
  1997年   128篇
  1996年   111篇
  1995年   84篇
  1994年   69篇
  1993年   64篇
  1992年   55篇
  1991年   50篇
  1990年   29篇
  1989年   17篇
  1988年   23篇
  1987年   4篇
  1986年   3篇
  1985年   40篇
  1984年   64篇
  1983年   44篇
  1982年   35篇
  1981年   14篇
  1980年   14篇
  1979年   12篇
  1978年   2篇
  1977年   6篇
  1973年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Abstract

In the pharmaceutical industry, a reverse payment (pay-for-delay) is a payment from an originator to a generic producer to delay her entry. In some recent cases, the US and EU antitrust authorities have banned these agreements per se, while in others they have used a rule of reason. This paper analyzes their dynamic effects and shows that a ban per se may reduce consumer surplus when the generic producer may go bankrupt and her financial situation is private information. Reverse payments are more beneficial when competition among few players is soft, the economy is in a downturn, and the period of drug usage after patent expiry is long. Results suggest that a rule of reason is more suited than a ban per se.  相似文献   
32.
Since the 1990s, firms in Japan have reduced their human capital investment in the workplace to minimize costs. Moreover, in response to the increase in the number of non-regular employees and turnover rates, workers need to have greater incentive to make the self-motivated investment in themselves for their self-protection. In this study, we first estimate the effects of workers’ self-motivated investment in themselves on wage rates. Next, we explore who is likely to participate in which training type and accordingly estimate the effects of the self-motivated investment on wage rates by training type. Our estimates controlling for individual-level fixed-effects indicate that the return is significantly positive and particularly high for practical training related to workers’ current jobs, and regular workers tend to self-select these higher-returns programs, while non-regular workers are more likely to enroll in lower-returns programs, such as schooling. This trend in investment in oneself could potentially increase the wage inequality between regular and non-regular workers through the self-selection of training types. Our estimates reveal that receiving the training and education benefit raises the likelihood for workers to participate in a high-return training program regardless of whether they are non-regular or regular workers. This suggests that government benefits on self-investment change workers’ self-selection of training type and serve to promote practical trainings that lead to high returns.  相似文献   
33.
苏南乡村地区一直是中国乡村建设的先行区域,特殊的纵横交错的水网结构构成了一个错综复杂的系统,呈现出其他地区不具有的复杂性和生态特殊性。随着城镇的扩张,乡村的发展建设使其水网空间的平衡发展面临极大的挑战。传统单一静态的规划方法逐渐显示出无法适应经济、社会等发展要求的缺陷。苏南乡村地区以水为核心,从水生态系统服务供需关系的视角下探究水网乡村的适应性规划策略更加适应当前的乡村现状和需求。以传统水网乡村空间形态转译为基础,建立水生态系统供需服务评估体系,在评估水生态系统服务供需能力的基础上,分析供需分异模式及供需矛盾。从构建乡村水域空间生态格局、乡村水域空间功能分区规划,以及乡村水域空间多情景预判3个方面,提出苏南水网乡村的适应性规划策略,并为水网乡村的生态实践提出新思路。  相似文献   
34.
Abstract

The paper aims to classify the quality cues and attributes of grated Parmigiano Reggiano cheese, an Italian traditional food cheese, exploring if they affect consumers’ quality perceptions and expectations. Analysis is based on a questionnaire administered in hypermarkets where grated Parmigiano Reggiano is sold. A factor analysis, using varimax rotation, and a cluster analysis, were performed, using the Stata 12 software package. The clusters used were: geographical origin and packaging (cluster 1); price, brand and quality certification (cluster 2); all sensory attributes (cluster 3); and a combination of sensory attributes with price, brand, and quality certification (cluster 4). This is the first study to examine the quality cues and attributes affecting quality perception and expectations of cheese for grated Parmigiano Reggiano from a consumer perspective. It is also the first to classify cheese attributes following a quality approach, encompassing previously studied sensory and other attributes.  相似文献   
35.
This study examines the relationship between economic policy uncertainty and mergers and acquisitions (M&As) in China. Using all listed Chinese companies on the Shanghai and Shenzhen Stock Exchanges as well as 4188 ​M&A deals from the period of 2001–2018, we show that Chinese firms are more likely to make acquisitions during periods of high economic policy uncertainty, which contradicts the behavior of US firms. We further show that state-owned enterprises (SOEs) are less likely than non-SOEs to make acquisitions during periods of high economic policy uncertainty. SOEs are less likely to use only cash for their acquisitions during periods of high economic policy uncertainty. These results indicate the prudence of SOEs regarding acquisitions relative to non-SOEs during periods of high economic policy uncertainty. Moreover, acquisitions during periods of high economic policy uncertainty are associated with an increase in shareholder wealth for acquirers, and this wealth effect is more pronounced for SOEs.  相似文献   
36.
We explore the role of ‘Workplace Monsters’ in the global burden of disease, including the $US1.15 trillion annual cost of depressive and anxiety disorders. We propose the productivity drain created by these individuals is a wicked problem, integrating several disciplines to position workplace monsters as significant corporate governance issues for organisations. Our discussion covers Monster prevalence, impacts on fellow workers and estimates of the costs incurred to business. We classify Monsters as ‘appreciating liabilities’ and call for future research to develop means of accounting for their inherent organisational costs in an effort to prompt action to address their destructive impacts.  相似文献   
37.
We challenge the view that PIPEs lead to unfavourable outcomes for issuing firms. We show that structured PIPEs do not have significant negative CARs when a matched firm benchmark is used for computing CARs and when sample selection bias is taken into account. Indeed, structured PIPEs have significantly higher positive skewness, indicating superior optionality, consistent with the real option argument. We also show that the 2002 intervention by the Securities and Exchange Corporation (SEC) has led to unintended consequences, with the substitution of ‘mom and pop’ investors for hedge fund investors in the structured PIPE market.  相似文献   
38.
党的十九大报告首次提出区域协调发展战略,要求各地充分发挥比较优势,加强政府间合作,着力解决区域发展不平衡不充分的问题。深汕合作区正是实施这一战略的典型代表。其中,政府的战略政策导向、经济全球化、区域一体化和非政府组织的发展是合作区得以形成的主要外部动力;区域协调发展、产业结构调整、官员升迁诉求是内部动力。但是,在合作区发展的过程中也存在一定的阻力。如地方保护主义的抬头、利益博弈、市场运作的行政化。因此,为促进地方政府间良性合作,应不断强化合作的正向激励,降低合作的阻力,保证区域府际合作的长久性。  相似文献   
39.
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   
40.
食品检测实验室中最为重要的就是质量监督管理工作,做好质量监督有利于提高实验室工作人员的质检与管理能力,进而推动有关人员的学习进步,以胜任工作岗位,提高该食品检测实验室的质量检测水平,确保检测数据的有效性与无误性。但现阶段我国的实验室由于缺乏统一的行业标准,导致其质量监督工作水平参差不齐,出现了一系列不利于质量检测的因素,比如质量监督目的不明、质量监督内容不完整、质量监督措施不完善等不足,都会影响该实验室对于食品的检测。因此,本文主要就食品检测实验室的质量监督方法进行探究,从各个方面指出质量监督的技术要点。  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