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   298篇
  免费   12篇
财政金融   32篇
工业经济   20篇
计划管理   84篇
经济学   59篇
综合类   4篇
运输经济   5篇
旅游经济   2篇
贸易经济   65篇
农业经济   14篇
经济概况   25篇
  2023年   4篇
  2021年   6篇
  2020年   4篇
  2019年   15篇
  2018年   9篇
  2017年   13篇
  2016年   8篇
  2015年   1篇
  2014年   7篇
  2013年   29篇
  2012年   14篇
  2011年   14篇
  2010年   12篇
  2009年   8篇
  2008年   14篇
  2007年   6篇
  2006年   8篇
  2005年   9篇
  2004年   8篇
  2003年   11篇
  2002年   9篇
  2001年   10篇
  2000年   6篇
  1999年   7篇
  1998年   10篇
  1997年   5篇
  1996年   8篇
  1995年   8篇
  1994年   4篇
  1993年   6篇
  1992年   9篇
  1991年   5篇
  1990年   5篇
  1989年   4篇
  1988年   1篇
  1987年   1篇
  1986年   3篇
  1985年   1篇
  1984年   2篇
  1983年   1篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1970年   1篇
排序方式: 共有310条查询结果,搜索用时 0 毫秒
151.
An evaluation of nature-based leisure and tourism as drivers for change in the Humberhead Levels is part of ongoing research with the Countryside Agency (CoAg). The Agency wishes to facilitate objectives of the Value in Wetness (Land Management Initiative) to re-establish wetlands and wetter landscapes across much of the area. To achieve a more sustainable wetland landscape with a vibrant farming and rural economy it is necessary to identify barriers and triggers for change. Diversification into nature-based leisure and tourism in the context of sustainable tourism, focusing on water- and wetland-related initiatives could be a way forward. This paper reports a scoping study and audit of outdoor leisure and tourism assets. It follows reviews of the Outdoor Leisure Industry (Beard et al., 2000) and the Wildlife Leisure Industry (Rotherham et al., 2000). These developed the importance of Wildlife Leisure as a concept in sustainable tourism and rural development. The Humberhead Levels research moves this from concept to near implementation. Relevant tourism information was collated to help establish the importance of the sector to a geographic area such as the Humberhead Levels. The reasons for current failings are noted. Case studies of selected wetland creation and restoration projects are presented and discussed. The research indicates significant contributions of nature-based leisure and tourism to regional and local economies. It also highlights problems of awareness, coordination and absence of the necessary support infrastructures at all levels. The importance of attracting new visitors and retaining local users is discussed.  相似文献   
152.
As part of a study investigating the naturally-occurring fractures in mafic rocks, two holes were drilled 450 m apart through the Palisades dolerite sill in New York. Well-2 is 229 m deep and Well-3 was drilled to 305 m, both penetrating through the sill and into the underlying Triassic sediments of the Newark Basin. Both holes were logged with downhole geophysical tools, including the BHTV, which acoustically images fractures intersecting the well. Understanding the fracture pattern, density, and porosity in the sill is essential for identifying possible zones of active fluid flow and high permeability. Using the BHTV logs, 96 and 203 fractures were digitally mapped within the sill in Well-2 and Well-3, respectively. Most fractures appear to dip steeply (76-78°). There is a shift in fracture orientation, however, and these fractures may or may not be continuous over the short lateral distance between Well-2 and Well-3. The lithology of the sill as identified by drill chips is nevertheless continuous between the holes. Both intersect a 7 m thick olivine-rich layer about 15 m above the bottom of the sill. Several fractures identified in Well-2 have large apparent aperture (>6cm) which correspond to high porosity zones (6-14%) observed in the logs. Resistivity logs were used to compute porosity using Archie's law and match well with the neutron porosity log in Well-2. We use the relationship between porosity and fracture aperture within the sill at Well-2 to infer the porosity in Well-3. High-porosity, large-aperture zones, including the target olivine layer, are identified in both holes. Changes in the temperature gradient log indicate active fluid flow in the sill, although flow appears to be most active in the sediments. Direct field measurements of bulk permeability, hydrologic modeling of fluid flow and calibration of fracture and log porosity will be undertaken in the future.  相似文献   
153.
154.
This paper introduces the idea of a forward-looking reference benchmark on both consumption and leisure in the context of a Ramsey–Cass–Koopmans growth model by assuming that in addition to consumption and leisure the household utility also depends on reference benchmarks of future anticipated consumption and leisure. We analyze the macrodynamic equilibrium, contrasting it to the case when the reference benchmarks are backward-looking. We investigate if the presence of anticipation in leisure can lead to smoother jumps in labor under productivity shocks and what effect that has on the consumption adjustment at the time of shock. We present our results using numerical simulations that confirm the existence of parameter spaces where a dual anticipation model leads to smaller jumps in labor, albeit sometimes at the expense of higher consumption jumps.  相似文献   
155.
International luxury businesses are challenged by the identification and satisfaction of the common needs and desires of global market segments. Although luxury goods have become available to a wider range of consumers, the traditional conspicuous consumption model has been transformed into a new experiential luxury sensibility that is marked by a change in the way that consumers define luxury. Based on an empirical study in collaboration with American, European, and Asian researchers, the results provide evidence that consumers in various parts of the world purchase or wish to purchase luxury products for varied reasons but that such consumers generally possess similar values. Regardless of their countries of origin, the basic motivational drivers of luxury consumers are similar among the financial, functional, personal, and social dimensions of luxury value perceptions, although the relative importance of these dimensions varies.  相似文献   
156.
High-performance computing provides unprecedented capabilities to produce higher resolution 4-D models in a fraction of time. Thus, the need exists for a new generation of visualization systems able to maintain parity with the enormous volume of data generated. In attempting to write this much data to disk, each computational step introduces a significant performance bottleneck, yet most existing visualization software packages inherently rely on reading data in from a dump file. Available packages make this assumption of postprocessing at quite a fundamental level and are not very well suited for plotting very large numbers of specialized particles. This necessitates the creation of a new visualization system that meets the needs of large-scale geodynamic modeling. We have developed such a system, gLucifer, using a software framework approach that allows efficient reuse of our efforts in other areas of research. gLucifer is capable of producing movies of a 4-D data set “on the fly” (simultaneously with running the parallel scientific application) without creating a performance bottleneck. By eliminating most of the human efforts involved in visualizing results through postprocessing, gLucifer reconnects the scientist to the numerical experiment as it unfolds. Data sets that were previously very difficult to even manage may be efficiently explored and interrogated without writing to disk, and because this approach is based entirely on memory distributed across as many processors as are being utilized by the scientific application, the visualization solution is scalable into terabytes of data being rendered in real time.  相似文献   
157.
Hostile takeover attempts oftentimes signal that a target firm has an over‐diversified and ineffective corporate strategy. What does this signal mean when takeover attempts fail? Drawing from agency theory, we argue that target firms managed by independent directory boards are likely to ignore the takeover attempt and not refocus their firms' strategy. Conversely, target firms managed by nonindependent boards are more likely to view the failed takeover attempt as a ‘wake‐up call’ and will refocus their firms' strategy so as to preserve the firm's survival. These arguments are tested using a sample of 76 firms that were targets of failed hostile takeover attempts. Logistic regression analyses confirm the predictions. This study suggests that in the aftermath of a failed takeover attempt board of director characteristics can help predict changes in corporate strategies. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
158.
We use seemingly unrelated regressions (SUR) and multivariate regression models (MVRM) in a panel sample of 74 American depository receipts (ADR) programs from Argentina, Brazil, Chile, and Mexico during the period May 1994 to May 2009 to analyze the behavior of ADR returns during the 300-day period surrounding the currency crises breakdown in the originator??s country. Controlling for the underlying stock and local and host country equity indices, we find that ADRs generate significant negative abnormal returns during currency crises, due to translation exposure. Abnormal returns remain statistically significant even in crises triggered by currency depreciations as small as 3.6%. The results persist after including exchange rate returns as a control variable and after an orthogonalization procedure of exchange rate against local country indices. In agreement with ADR literature, our results show that ADR prices are determined primarily by the underlying stock, exchange rates, and host country index, in that order. Moreover, we observe how market integration has become evident in more recent times as the coefficients for the U.S. stock market have increased its contribution to ADR price discovery.  相似文献   
159.
Crofting is a low intensity agricultural system restricted to the Highlands and Islands of northern Scotland typified by small scale mixed livestock production and rotational cropping activities. As with other low intensity farming systems across Europe, crofting is changing in response to a range of socio-economic factors. This is having a negative impact on the populations of rare bumblebees that are associated with this agricultural system. In this paper we use an ecological-economic modelling approach to examine the likely impacts of introducing two different management options for conserving bumblebees on croft land-use and income. Two linear programming models were constructed to represent the predominant crofting systems found in the Outer Hebrides, and varying constraints on bumblebee abundance were imposed to examine the trade-off between conservation and agricultural incomes. The model outputs illustrate that in some instances it is likely that both agricultural profits and bumblebee densities can be enhanced. We conclude that policy-makers should take into consideration the type of farming system when designing cost-effective agri-environment policies for low intensity farming systems, and that improvements in bee conservation are not necessarily in conflict with maintaining farm income.  相似文献   
160.
Fauchald SK  Smith D 《Nursing economic$》2005,23(3):131-5, 107
Health care professionals are expected to do more with less. Partnerships can be formed to gather information for research. Numerous opportunities exist for health care professionals to work with students in a wide variety of disciplines. Forming partnerships can result in a win-win situation for all involved.  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