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1.
A.  B.  K.  V.  A.  P.  I.  S.  E. 《Technological Forecasting and Social Change》2007,74(7):980-1029
We report here spatially explicit scenario interpretations for population and economic activity (GDP) for the time period 1990 to 2100 based on three scenarios (A2, B1, and B2) from the IPCC Special Report on Emissions Scenarios (SRES). At the highest degree of spatial detail, the scenario indicators are calculated at a 0.5 by 0.5 degree resolution. All three scenarios follow the qualitative scenario characteristics, as outlined in the original SRES scenarios. Two scenarios (B1 and B2) also follow (with minor adjustments due to scenario improvements) the original SRES quantifications at the level of 4 and 11 world regions respectively. The quantification of the original SRES A2 scenario has been revised to reflect recent changing perceptions on the demographic outlook of world population growth. In this revised “high population growth” scenario, A2r world population reaches some 12 billion by 2100 (as opposed to some 15 billion in the original SRES A2 scenario) and is characterized by a “delayed fertility transition” that is also mirrored in a delayed (economic) development catch-up, resulting in an initially stagnating and subsequently only very slow reduction in income disparities. The spatially explicit scenario interpretation proceeds via two steps. Through a combination of decomposition and optimization methods, world regional scenario results are first disaggregated to the level of 185 countries. In a subsequent second step, national results are further disaggregated to a grid cell level, taking urbanization and regional (rural–urban) income disparities explicitly into account. A distinguishing feature of the spatially explicit scenario results reported here is that both methodologies, as well as numerical assumptions underlying the “downscaling” exercise, are scenario-dependent, leading to distinctly different spatial patterns of population and economic activities across the three scenarios examined.  相似文献   
2.
Economists are increasingly interested in forecasting future costs and benefits of policies for dealing with materials/energy fluxes, polluting emissions and environmental impacts on various scales, from sectoral to global. Computable general equilibrium (CGE) models are currently popular because they project demand and industrial structure into the future, along an equilibrium path. But they are applicable only to the extent that structural changes occur in or near equilibrium, independent of radical technological (or social) change. The alternative tool for analyzing economic implications of scenario assumptions is to use Leontief-type Input-Output (I-O) models. I-O models are unable to endogenize structural shifts (changing I-O coefficients). However, this can be a virtue when considering radical rather than incremental shifts. Postulated I-O tables can be used independently to check the internal consistency of scenarios. Or I-O models can be used to generate scenarios by linking them to econometric macro-drivers (which can, in principle, be CGE models). Explicit process analysis can be integrated, in principle, with I-O models. This hybrid scheme provides a natural means of satisfying physical constraints, especially the first and second laws of thermodynamics. This is important, to avoid constructing scenarios based on physically impossible processes. Process analysis is really the only available tool for constructing physically plausible alternative future I-O tables, and generating materials/energy and waste emissions coefficients. Explicit process analysis also helps avoid several problems characteristic of pure CGE or I-O models, viz. (1) aggregation errors (2) inability to handle arbitrary combinations of co-product and co-input relationships and (3) inability to reflect certain non-linearities such as internal feedback loops.  相似文献   
3.
职业教育要以职业活动为导向,才能使教学内容尽可能贴近真实工作,培养符合企业需要的高素质技能人才,而情境作为教学的重要载体,直接影响教学效果和教学目标的实现。在构建项目化课程情境时,情境的选取与设计应根据工作的职业特性,体现典型性、全面性,还要结合教育规律,以学生为主体,具备趣味性特征,同时要根据行业企业的变化,及时更新和完善。  相似文献   
4.
Land Use and Land Cover (LULC) changes have profound impacts on the functioning of (agro)ecosystems and have potential to mitigate global climate change. However, we still lack interdisciplinary methods to project future LULC scenarios at spatial scales that are relevant for local decision making and future environmental assessments. Here we apply an interdisciplinary approach to develop spatially explicit projections of LULC at a resolution of 30 × 30 m informed by historic relationships between LULC and their key drivers, within the context of the four qualitative scenarios of global shared socioeconomic pathways. We apply this methodology to a case study in the Zona da Mata, Brazil, which has a history of major LULC changes. The analysis of LULC changes from 1986 to 2015 indicates that pasture area decreased from 76 to 58 % of total area, while forest areas increased from 18 to 24 %, and coffee from 3 to 11 %. Environmental protection legislation, rural credit for smallholder farmers, and demand for agricultural and raw products were identified as main drivers of LULC changes. Projected LULC for 2045 strongly depends on the global socioeconomic pathway scenarios, and forest and coffee areas may increase substantially under strong government measures in the environmentally conscious Green Road scenario or decrease in the high consumption Rocky Road scenario. Our study shows that under the set of drivers during the past three decades reforestation can go hand in hand with increase of agricultural production, but that major and contrasting changes in LULC can be expected depending on the socioeconomic pathway that will be followed in the future. To guide this process, LULC scenarios at the local scale can inform the planning of local and regional development and forest conservation.  相似文献   
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6.
In this introductory paper we introduce the special issue on “Backcasting for Sustainability”. We present briefly a historical background, and position backcasting in the wider context of future studies, in which it can be related to “normative forecasting” and normative scenarios. We reflect on the diversity and variety of backcasting studies and experiments, as presented in the ten papers for this special issue. After summarizing the papers we formulate a future research agenda.  相似文献   
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8.
Climate projections are based on emission scenarios. The emission scenarios used by the IPCC and by mainstream climate scientists are largely derived from the predicted demand for fossil fuels, and in our view take insufficient consideration of the constrained emissions that are likely due to the depletion of these fuels. This paper, by contrast, takes a supply-side view of CO2 emission, and generates two supply-driven emission scenarios based on a comprehensive investigation of likely long-term pathways of fossil fuel production drawn from peer-reviewed literature published since 2000. The potential rapid increases in the supply of the non-conventional fossil fuels are also investigated. Climate projections calculated in this paper indicate that the future atmospheric CO2 concentration will not exceed 610 ppm in this century; and that the increase in global surface temperature will be lower than 2.6 °C compared to pre-industrial level even if there is a significant increase in the production of non-conventional fossil fuels. Our results indicate therefore that the IPCC’s climate projections overestimate the upper-bound of climate change. Furthermore, this paper shows that different production pathways of fossil fuels use, and different climate models, are the two main reasons for the significant differences in current literature on the topic.  相似文献   
9.
The communication, joined with all its problems, became the topic for interesting studies during the mid of 90s. This attention was due to the publication of"Being Digital", wrote by Nicholas Negroponte, the first book that analyzed the communication environment in a comprehensive way. The novelty of this original book, which was immediately perceived by both the scientific and socio-economic environment, was twofold: The forecast of the revolutionary impact of digital technologies applied to the communication and the subsequent modified scenario. Nevertheless, the described scenario was contradicted or confirmed several times during last years.
The linkage between communication and socio-economic environment, after the publication of that book, represented a special focus for the scientific society since the beginning of the new millennium. The evolution of technologies involved several structural components in many different phases during last years and generated a lot of deep changes in a short time. These developing conditions made really difficult any forecasting attempt about the evolution of each technological component and, consequently, any reliable scenario for the communication environment.
The functional update of existing technologies leaded to the appearance of a new medium: Internet. This medium started with revolutionary peculiarities: low access and operating costs, multimediality, bidirectional way of usage and, above all, planetary target. The new communication tool seems to be a good candidate to substitute many of the former media or, at least, to reduce their usage in a meaningful way. Vice versa, the socio-economic effect of Internet was very weak: The new medium appears as simply added to the previous shape without meaningful influences on the diffusion of traditional media.
Nevertheless, the advantages offered by the technological innovation was not reserved only to Internet, but deeply changed all the media influencing particularly their way of supplying service. The most meaningful effects of these innovations involved both the diffusion systems and trading approach so generating a special attention also by politic environments.
The final objective of this paper is to analyze the evolution of the communication environment due to the innovation and to depict the actual communication offer. This approach will be useful to verify the conditions for reliable definition of scenarios.  相似文献   
10.
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