全文获取类型
收费全文 | 4341篇 |
免费 | 195篇 |
国内免费 | 41篇 |
专业分类
财政金融 | 328篇 |
工业经济 | 237篇 |
计划管理 | 702篇 |
经济学 | 1057篇 |
综合类 | 337篇 |
运输经济 | 80篇 |
旅游经济 | 190篇 |
贸易经济 | 415篇 |
农业经济 | 831篇 |
经济概况 | 399篇 |
信息产业经济 | 1篇 |
出版年
2024年 | 11篇 |
2023年 | 89篇 |
2022年 | 49篇 |
2021年 | 108篇 |
2020年 | 204篇 |
2019年 | 171篇 |
2018年 | 161篇 |
2017年 | 206篇 |
2016年 | 193篇 |
2015年 | 150篇 |
2014年 | 265篇 |
2013年 | 472篇 |
2012年 | 263篇 |
2011年 | 334篇 |
2010年 | 257篇 |
2009年 | 245篇 |
2008年 | 247篇 |
2007年 | 200篇 |
2006年 | 200篇 |
2005年 | 129篇 |
2004年 | 111篇 |
2003年 | 85篇 |
2002年 | 77篇 |
2001年 | 73篇 |
2000年 | 43篇 |
1999年 | 38篇 |
1998年 | 31篇 |
1997年 | 40篇 |
1996年 | 33篇 |
1995年 | 21篇 |
1994年 | 17篇 |
1993年 | 8篇 |
1992年 | 11篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1986年 | 2篇 |
1985年 | 7篇 |
1984年 | 7篇 |
1983年 | 8篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有4577条查询结果,搜索用时 31 毫秒
61.
Technological change in energy systems: Learning curves, logistic curves and input-output coefficients 总被引:1,自引:0,他引:1
Learning curves have recently been widely adopted in climate-economy models to incorporate endogenous change of energy technologies, replacing the conventional assumption of an autonomous energy efficiency improvement. However, there has been little consideration of the credibility of the learning curve. The current trend that many important energy and climate change policy analyses rely on the learning curve means that it is of great importance to critically examine the basis for learning curves. Here, we analyse the use of learning curves in energy technology, usually implemented as a simple power function. We find that the learning curve cannot separate the effects of price and technological change, cannot reflect continuous and qualitative change of both conventional and emerging energy technologies, cannot help to determine the time paths of technological investment, and misses the central role of R&D activity in driving technological change. We argue that a logistic curve of improving performance modified to include R&D activity as a driving variable can better describe the cost reductions in energy technologies. Furthermore, we demonstrate that the top-down Leontief technology can incorporate the bottom-up technologies that improve along either the learning curve or the logistic curve, through changing input-output coefficients. An application to UK wind power illustrates that the logistic curve fits the observed data better and implies greater potential for cost reduction than the learning curve does. 相似文献
62.
Jean-Louis Weber 《Ecological Economics》2007,61(4):695-707
The European Environment Agency has started the implementation of a programme of land use and ecosystem accounts, following the System of Environmental and Economic Accounts (SEEA) guidelines of the United Nations. The purpose is to integrate information across the various ecosystem components and to support further assessments and modelling of these components and their interactions with economic and social developments. This programme reflects the increasing demand for environmental policy integration in Europe, both vertically through thematic policies as well as horizontally across policies in those sectors that contribute most to environmental impacts. The construction of land and ecosystem accounts is now feasible due to continuous improvements in monitoring, collecting and processing data and progress with the development of statistical methods that facilitate data assimilation and integration. The accounts are based on explicit spatial patterns provided by comprehensive land cover accounts that can be scaled up and down using a 1 km2 grid to any type of administrative region or ecosystem zone (e.g., river basin catchments, coastal zones or bio-geographic areas). Land cover accounts have been produced for 24 countries in Europe and first results published in the European Environment State and Outlook2005 report of the EEA.1 相似文献
63.
This research examines the high level of change in supply organizations of large North American companies using data collected from 51 large North American supply organizations in 1987, 1995 and 2003. Analysis is supplemented by an additional 55 companies for which data were collected in 1995 and 2003. The availability of longitudinal data from individual companies over a 16-year period provided a unique opportunity to trace changes made to each company's supply organizational structure and their roles and responsibilities. Findings suggest that the respondents made major changes in supply organizational structure, supply chain responsibilities, use of purchasing teams, supply involvement in major corporate activities (MCA) and CPO reporting line, title and background. 相似文献
64.
Thomas Siebe 《Economic Systems Research》1996,8(2):183-194
For the maintenance and development of a disaggregated econometric model, the present paper deals with some aspects related to the identification of important intermediate transactions. First, some methodological aspects related to earlier works are discussed. By comparing the properties of different selection methods based on the recent West German input–output table, the calculations confirm the common finding that the necessary level of endogenization can be bounded meaningfully by an a priori investiga tion of the intersectoral transactions. This is also valid if the selection method considers restrictions that deal with the consistence of input–output tables and if some broader error criteria are applied. The main result of the empirical applications seems to be that some attention should be paid to temporal changes of important coefficients. 相似文献
65.
Most IS research in both the technical/rational and socio-technical traditions ignores or marginalizes the emotionally charged behaviours through which individuals engage in, and cope with the consequences of, IS practice and associated organizational change. Even within the small body of work that engages with emotions through particular conceptual efforts, affections are often conceived as a phenomenon to be eradicated – an affliction requiring a cure. In this paper, I argue that emotions are always implicated in our lived experiences, crucially influencing how we come to our beliefs about what is good or bad, right or wrong. I draw from the theoretical work of Michel Foucault to argue for elaborating current notions of IS innovation as a moral and political struggle in which individuals’ beliefs and feelings are constantly tested. Finally, I demonstrate these ideas by reference to a case study that had considerable emotional impact, and highlight the implications for future work. 相似文献
66.
经济快速发展地区农业土地利用变化驱动机制研究--以无锡市东亭镇、安镇镇和羊尖镇为例 总被引:12,自引:0,他引:12
以长江三角洲地区无锡市东亭镇、安镇镇和羊尖镇为例,通过应用德尔菲法和主成分分析法选择农地利用变化影响因素的基础上,构建了区域农业土地利用变化的驱动模型,并据此着重分析了区域农地数量变化与区域经济发展、城市化水平、农业集约化、城市(上海市)辐射力以及耕地保护政策变化之间的相互关系。研究结果表明,区域农业土地利用变化是上述因素综合作用的结果,并且在不同的乡镇,农地数量变化的驱动因素是有所差异的,而且区域社会经济发展的不同时期,各驱动因素的重要程度也是动态变化的。最后,作者就经济快速发展地区农业土地可持续利用管理提出若干政策建议,合理保护农地尤其是耕地资源;重视耕地质量占补平衡;依据农业产业发展态势,积极调整农地利用结构;推进非农产业升级,合理控制非农用地规模;进一步完善土地利用的经济约束机制和土地利用决策体系;加强区域合作,避免产业结构的趋同导致的土地利用结构的趋同;促进产业科技进步,提高土地利用占用效率。 相似文献
67.
S. J. Tol Richard 《Environmental and Resource Economics》1995,5(4):353-374
It is argued that estimating the damage costs of a certain benchmark climate change is not sufficient. What is needed are cost functions and confidence intervals. Although these are contained in the integrated models and their technical manuals, this paper brings them into the open in order to stimulate discussion. After briefly reviewing the benchmark climate change damage costs, region-specific cost functions are presented which distinguish tangible from intangible losses and the losses due to a changing climate from those due to a changed climate. Furthermore, cost functions are assumed to be quadratic, as an approximation of the unknown but presumably convex functions. Results from the damage module of the integrated climate economy modelFUND are presented. Next, uncertainties are incorporated and expected damages are calculated. It is shown that because of convex loss functions and right-skewed uncertainties, the risk premium is substantial, calling for more action than analysis based on best-guess estimates. The final section explores some needs for further scientific research. 相似文献
68.
In the EURURALIS project, a chain of models was used to predict the changes in sustainable development indicators for European human well-being, ecology and economy issues, for four alternative scenarios of the future socio-economic development. This paper describes the biodiversity analysis of the project. Models based on general relationships between environmental factors and biodiversity loss were combined with socio-economic, land-use and environmental models to derive data that were integrated into an interactive tool for policy makers. The biodiversity analysis takes into account the effects of land-use change, climate change, fragmentation by major roads, area of unfragmented patches, nitrogen deposition, forestry and disturbance. Results show that biodiversity is projected to decrease between now and 2030 in most countries for all scenarios, indicating that it is unlikely that the EU will be able to fulfill its commitment to stop biodiversity loss by 2010. This is mainly due to urbanization and increase in stress factors, and outweighs the area increase of nature arising from land abandonment. Merits, limitations and uncertainties of this approach to biodiversity assessment are discussed. 相似文献
69.
The study analyses the determinants of international telephone, telex, telegram and leased lines communication between the United States and 46 countries. It focusses on the role of multinational firms, international trading firms and new information technologies within the framework of the theory of transaction costs.Results of the econometric estimates suggest that: (a) technological conditions of telecommunication infrastructure, i.e., international diffusion lags of new information technologies, play an important role in the explanation of international telephone and telex telecommunication flows but not in the demand for telegraph and leased lines, (b) multinational firms use international telecommunication to reduce the coordination costs and are strong customers of leased lines and telephones, but less so of telex and telegrams, (c) international trading firms exhibit less clear preferences in the use of the different media to reduce transaction costs. 相似文献
70.
本文选用1985年和2005年两期土地利用现状图,借助MAPGIS软件,采用单一土地利用动态度和综合土地利用动态度等指数模型,分析了安太堡露天煤矿1985~2005年土地利用类型的数量变化和空间变化特征。结果表明:(1)各类土地利用类型综合动态度为2.07%;(;2)安太堡露天煤矿20年来各类土地利用类型的增减在空间上存在快速的变化,通过统计分析显示,灌木林地、工业用地、裸土地增加迅速,而旱地、未成林地大幅度减少;(3)安太堡露天煤矿空间动态演变特点为空间扰动剧烈、地类变化明显、空间变化持续时间长。 相似文献