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   29343篇
  免费   296篇
财政金融   4938篇
工业经济   1659篇
计划管理   4563篇
经济学   6502篇
综合类   572篇
运输经济   76篇
旅游经济   217篇
贸易经济   6301篇
农业经济   576篇
经济概况   3596篇
信息产业经济   45篇
邮电经济   594篇
  2020年   128篇
  2019年   191篇
  2018年   2565篇
  2017年   2339篇
  2016年   1500篇
  2015年   259篇
  2014年   356篇
  2013年   1252篇
  2012年   799篇
  2011年   2347篇
  2010年   2112篇
  2009年   1826篇
  2008年   1845篇
  2007年   2154篇
  2006年   332篇
  2005年   621篇
  2004年   686篇
  2003年   822篇
  2002年   487篇
  2001年   283篇
  2000年   277篇
  1999年   251篇
  1998年   243篇
  1997年   202篇
  1996年   206篇
  1995年   179篇
  1994年   178篇
  1993年   206篇
  1992年   185篇
  1991年   187篇
  1990年   153篇
  1989年   159篇
  1988年   143篇
  1987年   135篇
  1986年   147篇
  1985年   240篇
  1984年   236篇
  1983年   209篇
  1982年   193篇
  1981年   189篇
  1980年   202篇
  1979年   194篇
  1978年   159篇
  1977年   174篇
  1976年   142篇
  1975年   132篇
  1974年   123篇
  1973年   126篇
  1971年   92篇
  1970年   94篇
排序方式: 共有10000条查询结果,搜索用时 421 毫秒
991.
992.
Objective: To assess the cost-effectiveness of exenatide 2?mg once-weekly (EQW) compared to dulaglutide 1.5?mg QW, liraglutide 1.2?mg and 1.8?mg once-daily (QD), and lixisenatide 20?μg QD for the treatment of adult patients with type 2 diabetes mellitus (T2DM) not adequately controlled on metformin.

Methods: The Cardiff Diabetes Model was applied to evaluate cost-effectiveness, with treatment effects sourced from a network meta-analysis. Quality-adjusted life years (QALYs) were calculated with health-state utilities applied to T2DM-related complications, weight changes, hypoglycemia, and nausea. Costs (GBP £) included drug treatment, T2DM-related complications, severe hypoglycemia, nausea, and treatment discontinuation due to adverse events. A 40-year time horizon was used.

Results: In all base-case comparisons, EQW was associated with a QALY gain per patient; 0.046 vs dulaglutide 1.5?mg; 0.102 vs liraglutide 1.2?mg; 0.043 vs liraglutide 1.8?mg; and 0.074 vs lixisenatide 20?μg. Cost per patient was lower for EQW than for liraglutide 1.8?mg (?£2,085); therefore, EQW dominated liraglutide 1.8?mg. The cost difference per patient between EQW and dulaglutide 1.5?mg, EQW and liraglutide 1.2?mg, and EQW and lixisenatide 20?μg was £27, £103, and £738, respectively. Cost per QALY gained with EQW vs dulaglutide 1.5?mg, EQW vs liraglutide 1.2?mg, and EQW vs lixisenatide 20?μg was £596, £1,004, and £10,002, respectively. In the probabilistic sensitivity analysis, the probability that EQW is cost-effective ranged from 76–99%.

Conclusion: Results suggest that exenatide 2?mg once-weekly is cost-effective over a lifetime horizon compared to dulaglutide 1.5?mg QW, liraglutide 1.2?mg QD, liraglutide 1.8?mg QD, and lixisenatide 20?μg QD for the treatment of T2DM in adults not adequately controlled on metformin alone.  相似文献   
993.
To source external knowledge, firms in the service area use various sourcing modes simultaneously suitable for their internal needs or external environments. Each external knowledge sourcing mode has distinctive characteristics, and as such, they can offer different advantages and/or disadvantages to the firms. Thus, the effects of external knowledge sourcing on service innovation may vary depending on the sourcing modes. The current study aims to empirically examine the different effects of various external knowledge sourcing modes on service innovation. The study identifies three external knowledge sourcing modes: joint development, technology purchasing, and external information acquisition. Three hypotheses are established to examine the relationships between the extent of utilizing each mode and service innovation performance in terms of new service introduction. The data for analysis are selected from the “Korean Innovation Survey 2006: Service Sector” (KIS 2006). It is regarded as South Korea's version of the Community Innovation Survey (CIS). The KIS 2006 data set covers joint development, technology purchasing, and external information acquisition activities of corporations in the service sector in South Korea. The study empirically analyzes the data set using a negative binomial regression model. The results first demonstrate that the extent of the joint development has an inverted U‐shaped relationship with the service innovation performance. Second, the results indicate that, on the other hand, service innovation performance decreases with the increase to the extent of the technology purchasing when the extent is below the threshold. On the other hand, it increases with the increase to the extent of the technology purchasing; this occurs when the extent exceeds the threshold. Third, the results show that external information acquisition has a positive effect on service innovation performance. These findings support that the extent of utilizing each mode has different relationships with service innovation performance. The findings suggest that service firms need to utilize joint development at a moderate level, active technology purchasing, and as much external information acquisition as possible to maximize service innovation performance. In practice, this finding can help managers of service firms select appropriate external knowledge sourcing modes and determine the optimum level of use for each mode. This study also can help firms build up strategies for external knowledge sourcing.  相似文献   
994.
995.
We analyze optimal merger policy in R&D-intensive industries with product innovation aiming to improve the quality of products. Our results suggest that a permissive merger policy is rarely optimal in high-tech industries when the antitrust authority considers a welfare standard that balances the impact of mergers on consumers’ surplus and firms’ profits. In particular, relative to a benchmark where the effects from R&D are absent, we show that the optimal merger policy should not be substantially more permissive in the presence of those effects from R&D.  相似文献   
996.
This paper considers the assignment of tradable permits—representing property rights of an environmental good—to community members who are harmed by pollution generated by firms. These community members can in turn sell permits to polluters according to their personal preferences. For a special case with a sole household, market transactions between the household and polluters achieve an efficient pollution level. However, for a group of households, the decentralized market solution fails to yield social efficiency because of competitive consumption of the environmental goods. We design a revenue-sharing mechanism akin to unitization, under which market transactions also achieve efficient resource allocation. Importantly, in some cases, efficiency can be achieved even when regulators are ignorant of the private valuation of the environmental good.  相似文献   
997.
Ethical misconduct and violations seriously harm individuals and organizations and lead to massive fines or the dismissal of employees and CEOs. Many firms have implemented ethics programs to prevent unethical behavior but these are often ineffective and take a traditional approach. Ethics officers are often responsible for running and developing ethics programs, in collaboration with other departments. They can, therefore, play a key role in improving ethics program effectiveness. We postulate that ethics officers need to adopt a more innovative approach in order to achieve ethical behavior among employees and managers, and that such an innovative approach requires certain personality traits. This study investigates how ethics officers’ personality traits and innovative work behaviors relate to the effectiveness of ethics programs and normative ethical behavior through an online questionnaire conducted among 110 ethics officers in large Dutch organizations. Structural equations modeling showed that innovative work behavior mediated the relationship between ethics officers’ openness to experience and ethics program effectiveness which, in turn, is related to more normative ethical behavior. Future research must examine the (partial) mediation effects, including other characteristics of ethics officers in relation to ethics program effectiveness and ethical behaviors at work, and replicate the study multi‐nationally.  相似文献   
998.
Smart devices such as smartphones and tablets are used extensively in public spaces for the transmission and reception of content in the form of text, photos and streaming videos. Since the bandwidth provided for wireless access is limited in public areas, it becomes an issue for users to gain access to the bandwidth they need at the right times. While an omniscient controller could assign bandwidth to each device on the basis of their needs and overall availability, imperfect information about the instantaneous state of the wifi access patterns and needs of users make for a very inefficient allocation of such bandwidth. This paper provides a solution for bandwidth allocation by creating a market among users of smart devices so that they can bid for extra bandwidth when they need it and sell it when they don’t. They do so by using a virtual currency that is conserved so that each device owner maximizes his own utility. This utility function is composed of both the benefit accrued from accessing bandwidth and the loss of the currency incurred in bidding for such bandwidth. Extensive simulations show that this market-based method outperforms an omniscient model when demand is uncertain, while minimizing bandwidth consumption.  相似文献   
999.
The article considers the conditions of developing the aviation industry for long-term prospects taking into account factors such as changes in purchasing aviation equipment, progress in developing the Russian aviation market, and works for reconstructing and modernizing transport infrastructure in the Russian Arctic. The author aims to coordinate the Government programs for developing new aviation equipment and equipment for air transport via the program of Arctic Exploration and Development, as it is necessary to integrate various cycle flows with regard to high-tech capital.  相似文献   
1000.
Consumers are increasingly using technologies such as wearables or mobile apps to achieve their self-improvement goals. Such technologies often contain features that enable social interdependence (competition or cooperation) among users to support them in improving their engagement, performance, and well-being (life satisfaction and personal growth). However, the critical question remains: does competition or cooperation best serve users in attaining these self-improvement goals? Evidence from an online experiment and a field study reveals that competition is more effective in driving performance and personal growth, while cooperation is superior in terms of behavioral engagement and life satisfaction. Furthermore, the results indicate that the effects are mediated by strive for success and fear of failure, two counteracting psychological processes. While competition is the stronger trigger for both pathways, downstream effects vary depending on the self-improvement goal considered. This research thus provides insights into whether and how users can best realize their self-improvement goals using technologies that include social features.  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