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   131677篇
  免费   3757篇
  国内免费   2篇
财政金融   25325篇
工业经济   10911篇
计划管理   21212篇
经济学   28823篇
综合类   1457篇
运输经济   882篇
旅游经济   2476篇
贸易经济   21465篇
农业经济   6078篇
经济概况   16563篇
信息产业经济   7篇
邮电经济   237篇
  2021年   822篇
  2020年   1607篇
  2019年   2356篇
  2018年   2260篇
  2017年   2453篇
  2016年   2651篇
  2015年   2066篇
  2014年   3375篇
  2013年   15188篇
  2012年   4179篇
  2011年   4107篇
  2010年   3665篇
  2009年   4294篇
  2008年   3868篇
  2007年   3232篇
  2006年   3566篇
  2005年   3542篇
  2004年   3097篇
  2003年   2772篇
  2002年   2777篇
  2001年   2473篇
  2000年   2290篇
  1999年   2162篇
  1998年   2026篇
  1997年   2033篇
  1996年   1930篇
  1995年   1925篇
  1994年   1938篇
  1993年   1899篇
  1992年   1921篇
  1991年   1827篇
  1990年   1702篇
  1989年   1556篇
  1988年   1497篇
  1987年   1513篇
  1986年   1593篇
  1985年   2352篇
  1984年   2244篇
  1983年   2058篇
  1982年   1917篇
  1981年   1894篇
  1980年   1869篇
  1979年   1784篇
  1978年   1590篇
  1977年   1581篇
  1976年   1347篇
  1975年   1239篇
  1974年   1159篇
  1973年   1151篇
  1972年   864篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
Companies commonly issue sustainability or corporate social responsibility (CSR) reports. This study seeks to understand worldviews of corporate sustainability, or the corporate message conveyed regarding what sustainability or CSR is and how to enact it. Content analysis of corporate sustainability reports is used to position each company report within stages of corporate sustainability. Results reveal that there are multiple coexisting worldviews of corporate sustainability, but the most dominant worldview is focused on the business case for sustainability, a position anchored in the weak sustainability paradigm. We contend that the business case and weak sustainability advanced in corporate sustainability reports and by the Global Reporting Initiative are poor representations of sustainability. Ecological embeddedness, or a locally responsive strategy that is sensitive to local ecosystems, may hold the key to improved ecological sensemaking, which in turn could lead to more mature levels of corporate sustainability worldviews that support strong sustainability and are rooted in environmental science. This must be supported by government regulation. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment  相似文献   
22.
This research investigates what impact of uncertainty perception arising from the existence of competition has on the pricing decision for Product-Service Systems (PSS) under uncertainty. PSS provision is an increasingly important area for many businesses and competition increases cognitive pressures on providers even further. We present an experimental study with industrial costing and bidding experts from the defence and aerospace sector. The study consisted of an experimental set-up via two questionnaires which differed in the existence of competition in the bidding scenario. The findings showed that bidding decision makers changed their evaluation of the cost estimate due to the introduction of competition but kept their evaluations of the profit margin and price bids constant. Furthermore, the participants listed the relevant sources of uncertainty that influenced their decision-making process. This research contributes to the literature in two ways. First, our findings showed that predictions from current theory regarding decision-making of cost estimation and pricing are not confirmed when competitively bidding for PSS. Second, we show uncertainty sources that influenced the decision makers and identified p the importance of internal processes of the PSS provider and environmental uncertainty.  相似文献   
23.
Conventional wisdom holds that in markets with positive feedbacks being first to market can matter more than product quality. In this paper, we test that intuition within a generalized Pólya urn model. We find that if we assume constant feedbacks, in the long run, higher quality products dominate the market regardless of initial market shares, contradicting the common wisdom. However, when we allow for variable feedbacks, initial advantages persist almost indefinitely. Thus, the choice of whether to rush to market or focus on quality depends on market characteristics such as whether the positive feedbacks result from more consistent returns to scale or from more variable social influences.  相似文献   
24.
This article makes an initial attempt to study the hedging effectiveness of Islamic stock returns against inflation for different investment horizons. We applied the wavelet analysis to measure the cross-correlations between the time series as a function of time-scales using data ranging from 2007 to early 2015. The main results tend to indicate the following: First, that for investment horizons not exceeding 3 years, the FTSE Bursa Malaysia Emas Shariah Index constituent returns may potentially hedge against inflation. Additionally, the hedging ability of stock returns was absent from 2008 to 2009 following the global financial crisis. Finally, a buy-and-hold strategy exceeding 3 years may erode investments. The results are plausible and have strong policy implications.  相似文献   
25.
We evaluate an agricultural extension program aimed at increasing on‐farm biodiversity in Alberta. Using reports prepared for program participants by the extension agency, customized surveys were used to collect data on whether recommended practices were adopted. Data were also collected from producers who were willing but unable to participate in the program due to its unexpected cancellation. A count model compared the number of practices adopted by participants and nonparticipants to evaluate the program's efficacy, and a probit model using participants’ adoption data were used to understand factors affecting adoption. Simple, low‐cost, and easily trialed practices were adopted at high rates, though some higher cost practices associated with observable benefits were also adopted at moderate or high rates. Farm‐specific characteristics, such as size, tenure, or group membership were also significantly linked to the likelihood of adoption. Results suggest that the extension program was successful in encouraging adoption of environmentally beneficial practices with caveats; project completion and quality were not verified, and decreasing marginal returns to extension efforts may have been realized within the small participant pool. Nous évaluons un programme d'éducation permanente en agriculture visant l'augmentation de la biodiversité fermière en Alberta. Utilisant des rapports préparés par les agences d'éducation pour les participants de programmes, des sondages individualisés ont servi à la collecte de données concernant l'adoption de pratiques recommandées. Des données ont aussi été recueillies auprès de producteurs qui auraient voulu participer mais qui n'ont pas profité du programme suivant son annulation inattendue. Un modèle de comptage a servi à comparer le nombre de pratiques adoptées par les participants et non‐participants pour évaluer l'efficacité du programme, et un modèle probit basé sur les données d'adoption par les participants a servi à comprendre les facteurs ayant un impact sur l'adoption. Les pratiques simples, peu coûteuses et faciles à tester ont été hautement adoptées. Certaines pratiques à coûts plus élevés, associées à des avantages observables, ont aussi vu des taux moyens et élevés d'adoption. Les caractéristiques spécifiques aux exploitations agricoles comme la taille, la longévité et l'adhésion à un groupe se sont aussi trouvées liées de façon significative aux probabilités d'adoption. Les résultats suggèrent que le programme d'éducation permanente a réussi à encourager l'adoption de pratiques bénéfiques pour l'environnement avec quelques bémols: la réalisation des projets et leur qualité n'ont pas fait l'objet de vérification, et la diminution des rendements marginaux en fonction des efforts d'éducation pourrait avoir été réalisée dans le cadre d'un petit bassin de participants.  相似文献   
26.
This study aimed to describe the distribution of injury mechanisms and to assess the impact of those mechanisms on the morbidity and mortality of trauma. All patients admitted to Puerto Rico Trauma Hospital (2002–2011) for road-traffic collisions (RTCs, 5,371), gunshot wounds (GSWs, 2,946), falls (2,319), pedestrian accidents (1,652), and stab wounds (SWs, 1,073) were selected. Gunshot victims were 1.19 (95%CI: 1.07–1.33) times as likely as road-traffic victims to have an ISS ≥25. Pedestrians were 1.76 (95%CI: 1.49–2.09) times more likely to have a GCS ≤8 than road-traffic victims were. The risk of dying was 2.64 (95%CI: 2.20–3.16) times higher for gunshot victims and 1.51 (95%CI: 1.23–1.86) times higher for pedestrians compared to patients who had had RTCs. Gunshot victims and pedestrians had the worst clinical outcomes. Accordingly, these patients should receive the most aggressive clinical management. Furthermore, it is imperative to develop public health campaigns on trauma prevention.  相似文献   
27.
The Bullionist Controversy in the United Kingdom is one of the first debates about the determination of the price level and the exchange rate under a paper money standard. Despite the importance of the debate in the development of monetary theory, there remains little empirical evidence that uses modern, multivariate time series techniques. The evidence that does exist provides support for the Anti‐Bullionist position. The purpose of this paper is to review the debate and develop a dynamic general equilibrium model that is capable of capturing key features of the nineteenth‐century British financial system. The model is estimated using Bayesian procedures to test the competing hypotheses. The paper provides support for the Bullionist position.  相似文献   
28.
This paper aims to provide a deeper understanding of transition drivers by reviewing four major strands of inquiry in transition studies: Multi Level Perspective (MLP); Strategic Niche Management (SNM); Transition Management (TM); Technological Innovation Systems (TIS). To the best of our knowledge, none of these contributions have so far provided a clear-cut classification of main drivers of transitions, as evidenced by the difficulty of practitioners in reaching goals as entrepreneurs, or policy makers in supporting economic growth. We believe that these theoretical streams share views relating the origin and drivers of transitions and that the analysis of the multi-level developments and systemic sub-processes by using the Integrative Propositional Analysis (IPA) allows for a more comprehensive identification of transition drivers. By mapping causal relationships within each perspective and by developing an integrative framework that takes in due account of overlaps between theories, we derived a new conceptual structure for the identification of transitions’ drivers.  相似文献   
29.
30.
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