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Sustainable technology development implies large changes in technological systems. The illustrative process ‘hydrogen fuel cell in a boat’ is used here as an example of a learning process concerning a transition towards a hydrogen economy. Theoretically the concepts of constructive technology assessment, back-casting and social niche management are combined in this approach.  相似文献   
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A revised definition of efficiency compares portfolios with different net worths. One axiom rules out instantaneous riskless gains, the other asserts that it costs money to buy good portfolios. Unlimited short sales are allowed. Portfolios which cannot be improved at any price are called absolutely efficient. The geometry of the mean-standard deviation frontiers is governed by three “efficient set constants”. A few results regarding efficient portfolios must be modified, and a new version of the security line equation is proposed. Explicit formulas are given: no need to use different formulas for singular or non-singular covariance matrix.  相似文献   
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A computer-based simulator was used for training operators prior to the start-up of a new fertilizer complex which includes a 1,350-MTPD ammonia plant, two 1,100-MTPD urea plants, and a steam and power generation plant with two 18-MW gas turbines. The simulator offered many benefits, which can be used for continued education of operators and engineering studies.  相似文献   
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The sustainable livelihoods (SL) approach offers a holistic framework and a practical toolkit to analyze tourism's impacts and interactions within a community. This study argues that the usefulness of the SL approach in tourism can be enhanced by ensuring that the approach is built on a genuine people-centered starting point. The exploration of the local community's representations of, and aspirations for, their roles in tourism as a future livelihood choice meets this need. To verify the value of this approach empirically, this study examined the case of Lhasa, Tibet, and local youth as the research respondents. The findings suggest that the young hosts in Lhasa urban area were heterogeneous in their responses to tourism as a future livelihood choice. They fell into four subgroups: in-betweeners, ambivalent supporters, alternative supporters, and lovers. Further, this study examined the profiles of these four subgroups and explored their responses. The study enhances the SL approach by taking tourism as an example and clearly defining the departure point for its adoption within the context of broader livelihoods portfolios. Additionally, it suggests some potential directions for tailored management strategies to meet youth and community perspectives.  相似文献   
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Consuming dark tourism: A Thanatological Perspective   总被引:3,自引:0,他引:3  
Despite increasing academic attention paid to dark tourism, understanding of the concept remains limited, particularly from a consumption perspective. That is, the literature focuses primarily on the supply of dark tourism; less attention, however, has been paid to the demand for ‘dark’ touristic experiences. This theoretical paper seeks to address this gap in the literature. Drawing upon the contemporary sociology of death, it explores the relationship between socio-cultural perspectives on mortality and the potential of dark tourism as a means of confronting death in modern societies. In so doing, it proposes a model of dark tourism consumption within a thanatological framework as a basis for further theoretical and empirical analysis of dark tourism.  相似文献   
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If future demand for maize in Latin America and the Caribbean region (LAC) is to be met from local sources, domestic production must continue to increase. Because further expansion in the area planted to maize is precluded by the limited availability of arable land, future increases in production will have to rely heavily on the spread of productivity‐enhancing hybrid technology. Until now, the diffusion of hybrid maize in LAC has been quite variable. Using data from 18 countries, we investigate factors affecting the hybrid maize diffusion rate. Our findings validate conventional profitability‐based explanations of producer adoption behavior, but they also confirm the importance of supply‐side factors, thereby providing empirical support for the life cycle theory of seed industry development. We conclude that if policy makers in LAC are to accelerate the diffusion of hybrid maize, they will have to ensure an environment in which it is not only profitable for producers to adopt improved germplasm, but also profitable for the seed industry to produce and sell high‐quality seed.  相似文献   
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On the morrow of President Truman's election the newspapers announced that the first person the President had received was the President of the powerful American syndical organisation known throughout the world under the name of C.I.Q. (Congress of Industrial Organizations). We know that this organisation as well as the other central organisation, the American Federation of Labour, had unequivocally taken up its stand in favour of Truman's candidacy. As the legislative elections had at the same time given the majority to the Democratic Party it was immediately declared on all hands that trade-unionism was going to exert considerable influence on American policy. These facts conferred a great importance on the memorandum addressed by Mr. Philipp Murray, in November 1947, to President Truman; a memorandum which was officially communicated by the C.I.O. to the International Trades Unions Conference for the recovery and reconstruction of Europe held in London on the 9th and 10th of March, 1948. We are especially pleased to put this document, which constitutes a declaration of principles of tie utmost interest, before the readers of the Annals.  相似文献   
30.
External wealth, the trade balance, and the real exchange rate   总被引:1,自引:0,他引:1  
We examine the link between the net foreign asset position, the trade balance and the real exchange rate. In particular, we decompose the impact of a country's net foreign asset position (‘external wealth’) on its long-run real exchange rate into two mechanisms: the relation between external wealth and the trade balance; and, holding fixed other determinants, a negative relation between the trade balance and the real exchange rate. We also provide additional evidence that the relative price of nontradables is an important channel linking the trade balance and the real exchange rate.  相似文献   
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