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   22989篇
  免费   713篇
  国内免费   13篇
财政金融   4361篇
工业经济   1984篇
计划管理   3929篇
经济学   4880篇
综合类   377篇
运输经济   203篇
旅游经济   464篇
贸易经济   4031篇
农业经济   1255篇
经济概况   2205篇
邮电经济   26篇
  2023年   100篇
  2021年   164篇
  2020年   303篇
  2019年   435篇
  2018年   511篇
  2017年   555篇
  2016年   515篇
  2015年   381篇
  2014年   578篇
  2013年   2427篇
  2012年   664篇
  2011年   728篇
  2010年   673篇
  2009年   780篇
  2008年   825篇
  2007年   740篇
  2006年   675篇
  2005年   618篇
  2004年   563篇
  2003年   589篇
  2002年   544篇
  2001年   492篇
  2000年   497篇
  1999年   449篇
  1998年   439篇
  1997年   460篇
  1996年   414篇
  1995年   394篇
  1994年   377篇
  1993年   384篇
  1992年   363篇
  1991年   345篇
  1990年   319篇
  1989年   280篇
  1988年   231篇
  1987年   275篇
  1986年   246篇
  1985年   369篇
  1984年   411篇
  1983年   383篇
  1982年   340篇
  1981年   320篇
  1980年   282篇
  1979年   289篇
  1978年   211篇
  1977年   213篇
  1976年   190篇
  1975年   138篇
  1974年   149篇
  1973年   132篇
排序方式: 共有10000条查询结果,搜索用时 578 毫秒
991.
ABSTRACT

Naturalists argue that the greatest threat to the natural world may be our “extinction of experience” with it. We know that place matters, but what can work to restore care between people and place? In this article, I will argue that illustrated journals can reinvigorate our experience with the world. By including text and image, science and art, illustrated journals incorporate different ways of knowing. Drawing draws us into the world as we pay attention to easily missed details. Writing complements drawing by providing a space for synthesizing or imagining about the observed. Like any skilled practice, journaling transforms our understanding of the world. My illustrated field journals began when I sensed that care for today’s world demanded more tools than what my training as an ecologist, alone, could offer. Illustrated journaling can begin with a few simple drawing and writing exercises – several of which I will describe in this article. As an immersive practice in place, the process of illustrated journals matters more than the product. Page by page, illustrated journals recognize the interpretive encounters so foundational to worldmaking and, in doing so, cultivate the deep attention to, and experience of, the world that is our first step toward care.  相似文献   
992.
Teachers’ knowledge of STEM education, their understanding, and pedagogical application of that knowledge is intrinsically linked to the subsequent effectiveness of STEM delivery within their own practice; where a teacher’s knowledge and understanding is deficient, the potential for pupil learning is ineffective and limited. Set within the context of secondary age phase education in England and Wales (11–16 years old), this paper explores how teachers working within the field of design and technology education acquire new knowledge in STEM; how understanding is developed and subsequently embedded within their practice to support the creation of a diverse STEM-literate society. The purpose being to determine mechanisms by which knowledge acquisition occurs, to reconnoitre potential implications for education and learning at work, including consideration of the role which new technologies play in the development of STEM knowledge within and across contributory STEM subject disciplines. Underpinned by an interpretivist ontology, work presented here builds upon the premise that design and technology is an interdisciplinary educational construct and not viewed as being of equal status to other STEM disciplines including maths and science. Drawing upon the philosophical field of symbolic interactionism and constructivist grounded theory, work embraces an abductive methodology where participants are encouraged to relate design and technology within the context of STEM education. Emergent findings are discussed in relation to their potential to support teachers’ educational development for the advancement of STEM literacy, and help secure design and technology’s place as a subject of value within a twenty-first Century curriculum.  相似文献   
993.
城市土地空间结构演变及其驱动机制分析   总被引:11,自引:0,他引:11  
城市土地利用空间结构及其演变一直是城市地理学、城市经济学、城市规划学、土地利用学等学科研究的核心与热点问题.当前我国城市土地利用正处在快速城市化的开端,在未来近半个多世纪的时期中,将一直处于急剧突变进程之中.加强对我国城市土地空间结构演变及其驱动机制的研究,有助于我们从城市用地结构演变的根源分析问题.本文简要概括了城市土地利用空间结构的相关研究,分析了城市用地空间结构演变在空间上的两种表现形式,并在此基础上分析了城市用地空间结构演变的动力主体、驱动力和驱动机制,以期为更好地促进城市土地利用结构的优化提供相应的参考.  相似文献   
994.
The new information and communication technologies have made it possible to view films in different spaces. Using the symbolic interactionist framework as a frame of analysis, we interpret the meaning of the two experiences of viewing technology-mediated films in the home and in the cinema. We conducted field research during the first half of 2009, digitally recording 16 interviews with research participants living in Barcelona (Spain). The interviews were transcribed verbatim with the help of voice-recognition software. Reports from our research participants indicate that individuals considered only the cinema experience to be a true leisure activity, while the home experience was interpreted as a routine recreational activity. Therefore, the meanings of the film-viewing activity were associated with the symbolic properties of the frames of interpretation. Finally, we discuss the implications of these findings for the home as a unified centre where shared meanings are co-produced by family members.  相似文献   
995.
Given the rising popularity of mass-participant sport, such as walking and running events, research has started to address whether these types of events could promote life satisfaction for participants. Nevertheless, the theoretical link between event participation and life satisfaction has not been fully elaborated. Using bottom-up theory of life satisfaction, this study examined the role of event satisfaction and the three facets of leisure involvement – attraction, centrality and self-expression – in people’s life domain satisfaction and life satisfaction. Participants (N = 236) were recruited from a walking event held in western Japan. The results of the study revealed that event satisfaction had positive, indirect effects on life satisfaction through satisfaction with family life and personal achievement. Attraction in walking also had positive, indirect effects on life satisfaction through satisfaction with family life, personal achievement and social life. In contrast, centrality and self-expression in walking were not associated with satisfaction with any life domains and life satisfaction. Findings from this study highlight the importance of life domain satisfaction in the relationship between event satisfaction, leisure involvement and life satisfaction. These findings also suggest that walking events can promote life satisfaction by providing the enjoyment of walking as physically active leisure.  相似文献   
996.
This paper develops direct tests for search behavior in retail gasoline markets. We exploit a unique market‐level dataset that allows us to directly measure search intensity with daily web traffic data from a gasoline price reporting website and perfectly measure daily changes in price levels and dispersion. Our simple yet powerful tests provide strong evidence of both cross‐sectional and intertemporal price search.  相似文献   
997.
Germany’s energy turnaround is leading to an increasing integration of photovoltaics (PVs) throughout its distribution grid. To ensure safe grid operation in times of high solar radiation, PV plants must either be throttled back to comply with the feed-in limitation or store a portion of their excess electricity in batteries. This paper presents a grid-optimized operating strategy for PV storage systems based on a Fuzzy Logic Controller that reduces peak feed-in and thus also PV curtailment losses. The Fuzzy Logic Controller uses data on PV power surplus and battery charge level as input variables. To obtain good results, the set of numerical parameters of the membership functions is enhanced by evolutionary programming.The energetic assessment shows that even small electrical storage capacities (<<5?kWh) reduce curtailment losses considerably when using the grid-optimized operating strategy. The economic assessment shows that, in 2016, investments in PV storage systems with large PV plants and small batteries have small (positive) Internal Rates of Return. The system efficiency of the battery storage has a small impact on the profitability of PV storage systems, whereas the cycle stability and the electricity purchase price have a large impact. Moreover, there is an economic benefit for plant operators to switch from the simple to the grid-optimized operating strategy. Solar forecast inaccuracies and variations in load and generation profiles have a negligible impact on the performance of the control algorithm.  相似文献   
998.
We propose a measure of business risk in air travel demand at the route level that can reduce information asymmetry during route development negotiations between tourism destinations and airlines. Aviation-exposed risk (AER) conveys information about the level of uncertainty with regard to air travel demand from an airline’s perspective. Using AER, tourism destinations and air service development teams can evaluate their risks from the perspective of the airline and its network. From there, an assessment can be made as to the value of air services in certain circumstances, including whether a direct underwrite or risk share between airlines and destinations is viable and necessary. By applying a portfolio analysis to an airline’s network, we find evidence that AER does indeed mimic the actual capacity distribution of the network. This provides support for AER as a useful risk measure to be used in practice.  相似文献   
999.
Research summary : In family businesses, investment decisions often involve both socioemotional wealth and economic considerations. Focusing on new technology adoption, we argue that multiple dimensions of socioemotional wealth contribute to complex effects within different types of family firms—depending on the level of family control—as well as in contrast to non‐family firms. Results based on cable TV operators from 1983 to 1987 confirm that family ownership correlates negatively with technology adoption, especially when family owners hold a minority rather than majority position. We also show contingencies based on performance improvements and competitive threats. Our arguments contribute new insights about the tensions between economic and socioemotional factors within minority family ownership that are absent from non‐family firms and more pronounced than in majority family firms. Managerial summary : We find evidence of greater reluctance toward new technology adoption among firms with minority family influence than majority family influence. This suggests that goals related to socioemotional wealth only partly explain the cautious decision‐making observed in family firms, with further caution arising from conflicting priorities between family and non‐family owners. Recent performance improvements help offset the reluctance to adopt new technology, albeit to a lesser degree among firms with minority family ownership. High levels of competitive threats also offset the reduction in new technology adoption, and contrary to expectations, to a greater extent among minority family firms. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
1000.
R esearch summary : Agency theory suggests that external governance mechanisms (e.g., activist owners, the market for corporate control, securities analysts) can deter managers from acting opportunistically. Using cognitive evaluation theory, we argue that powerful expectations imposed by external governance can impinge on top managers' feelings of autonomy and crowd out their intrinsic motivation, potentially leading to financial fraud. Our findings indicate that external pressure from activist owners, the market for corporate control, and securities analysts increases managers' likelihood of financial fraud. Our study considers external governance from a top manager's perspective and questions one of agency theory's foundational tenets: that external pressure imposed on managers reduces the potential for moral hazard. M anagerial summary : Many of us are familiar with stories about top managers “cooking the books” in one way or another. As a result, companies and regulatory bodies often implement strict controls to try to prevent financial fraud. However, cognitive evaluation theory describes how those external controls could actually have the opposite of their intended effect because they rob managers of their intrinsic motivation for behaving appropriately. We find this to be the case. When top managers face more stringent external control mechanisms, in the form of activist shareholders, the threat of a takeover, or zealous securities analysts, they are actually more likely to engage in financial misbehavior. Copyright © 2016 John Wiley & Sons, Ltd.  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