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   140748篇
  免费   4014篇
  国内免费   1篇
财政金融   26381篇
工业经济   12398篇
计划管理   22513篇
经济学   30297篇
综合类   1463篇
运输经济   1032篇
旅游经济   2623篇
贸易经济   24093篇
农业经济   6379篇
经济概况   17315篇
信息产业经济   7篇
邮电经济   262篇
  2021年   884篇
  2020年   1706篇
  2019年   2494篇
  2018年   2470篇
  2017年   2624篇
  2016年   2837篇
  2015年   2183篇
  2014年   3533篇
  2013年   15857篇
  2012年   4373篇
  2011年   4529篇
  2010年   4019篇
  2009年   4592篇
  2008年   4152篇
  2007年   3474篇
  2006年   3797篇
  2005年   3716篇
  2004年   3260篇
  2003年   3070篇
  2002年   2987篇
  2001年   2696篇
  2000年   2656篇
  1999年   2512篇
  1998年   2374篇
  1997年   2409篇
  1996年   2248篇
  1995年   2054篇
  1994年   2063篇
  1993年   2030篇
  1992年   2087篇
  1991年   1974篇
  1990年   1854篇
  1989年   1725篇
  1988年   1634篇
  1987年   1647篇
  1986年   1711篇
  1985年   2489篇
  1984年   2374篇
  1983年   2161篇
  1982年   2040篇
  1981年   1950篇
  1980年   1925篇
  1979年   1847篇
  1978年   1662篇
  1977年   1651篇
  1976年   1410篇
  1975年   1299篇
  1974年   1211篇
  1973年   1211篇
  1972年   910篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
Abstract

Traditional warranty analysis focuses on the reliability of a product and offers warranty designs that compensate a consumer if the item fails. We introduce the concept of a performance-based warranty (PBW) that guarantees that a product will operate at or above some baseline level of performance, such as a minimum energy efficiency for an appliance. We illustrate how consumer behavior can change in the presence of a PBW and define the parameters for which a manufacturer may increase revenue. Finally, we present an algorithm to solve for the optimal PBW design given a consumer’s belief about the expected performance of the product.  相似文献   
22.
23.
President Biden was sworn in on January 20, 2021 after a 4‐year term by President Trump. Certainly, Trump's norm breaking presidency impacted Canada in significant ways and the agricultural sector was no exception. In this issue, we have a set of four short articles discussing the possible implications on Canadian agriculture of transitioning from a Trump to Biden presidency. Issues related to Canada‐U.S. agricultural trade, political norms and uncertainty, U.S. domestic support, participation in trade agreements, and U.S.‐China relations are all considered.  相似文献   
24.
25.
Additive manufacturing (AM) appears to be a particularly attractive use case for blockchain. This research combines inductive in‐depth interviews with the Delphi method to explore what potentials blockchain technology in AM creates, which adoption barriers firms need to overcome, and how supply chains will be affected by the integration of these two potentially disruptive technologies. The results suggest opportunities that are related to intellectual property (IP) rights management, the monitoring of printed parts throughout their lifecycle, process improvements, and data security. The most important barriers for blockchain adoption in AM are an absence of blockchain‐skilled specialists on the labor market, missing governance mechanisms, and a lack of firm‐internal technical expertise. By addressing important limitations of AM, blockchain is expected to improve the competitiveness of AM in parts’ production, catalyzing the trend toward more decentralized manufacturing resulting in more agile, resilient, and flexible supply chains and reduced logistics costs. Beyond that, blockchain‐based AM platforms are expected to enhance supply chain visibility, drive supply chain digitalization, support supply chain finance, and contribute to the emergence of shared factory systems.  相似文献   
26.
State-owned enterprises (SOEs) are commonly associated with undue advantages due to preferential treatment by the state. Simultaneously they are often quoted as handicapped given the notorious state interference, management problems and agency tensions. They used to be regarded as a mainly domestic issue but in the context of globalisation and the fact that states enter treaties with new obligations, SOEs’ performance ceased to be solely a domestic problem, increasingly so as state-owned multinational enterprises (SOMNEs) emerge. This article presents the results of research on Polish SOEs’ outward foreign direct investment (OFDI). It offers an overview of overseas activities of nine major Polish firms with a state stake and aims to contribute to the conceptual literature on foreign investments conducted by SOMNEs. We distinguish between FDI by SOMNEs as specific – privileged (facilitated) or discriminated (hampered) – investments subject to the home country’s state power and the host country’s state perception.  相似文献   
27.
28.
Private equity performance, both for buyouts and venture capital, has been highly cyclical: periods of high fundraising have been followed by periods of low performance. Despite this seemingly predictable variation, we find modest gains, at best, to pursuing realistic, investable strategies that time capital commitments to private equity. This occurs, in part, because investors can only time their commitments to funds; they cannot time when commitments are called or when investments are exited. There is a high degree of time-series correlation in net cash flows even across commitment strategies that allocate capital in a very different manner over time.  相似文献   
29.
30.
Most development projects encounter a highly uncertain entitlement process that is largely uncontrollable by developers. In this study, entitlement is modeled as a separate stage within a compound real option, where developers begin with minimal control (maximum risk) and each successful stage increases control (decreases risk). We solve the model analytically, provide three‐dimensional numerical comparisons, and empirically test the model's predictions using hand collected rezoning petitions. Our main result refines the classic development option model: developers first invest early (secure entitlements) in order to obtain the option to subsequently delay investment (construct the optimal building at the optimal time).  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