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1.
National Park of Tijuca in Rio de Janeiro (Brazil) is about 3,300 ha and considered the largest urban forest in the world. Its floristic composition is typical of Atlantic Rain Forest. The reserve is being altered because of fire occurrences and urban expansion. This study identified locations and causes of forest fires, and makes management recommendations to restore damaged areas. From 1991 to 2000, forest firefighters recorded an average of 75-fire occurrences/year. Identified causes included hot air balloons (24%), intentional (24%), rubbish burning (21%) and religious practices (17%). Primary fuels included invasive grasses and ferns. Although hot air balloons destroyed larger areas of forest in each occurrence, a greater number of fires started in the invasive vegetation along roads that bisect the forest. In response to recurrent forests, invasive vegetation has spread gradually into the forest increasing forest degradation. To decrease fire damage, sites with high fire frequencies and density of invasive vegetation were planted with less flammable species. Results indicate that fire frequency decreased and density of invasive vegetation declined. This approach appears to prevent fire incidence, reduce the need for fire fighting, and preserve existing biodiversity.  相似文献   
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This study investigated the relationship between the level of arousal (Heart Rate) and the number of erroneous perceptions among video poker players. Twelve regular and twelve occasional gamblers participated in a gambling session conducted in a natural environment. It was hypothesised that 1) a significant positive correlation would be observed between arousal and the number of erroneous verbalizations, 2) regular players would show a higher level of arousal than occasional players, and 3) they would emit more erroneous verbalizations. Results showed that hypotheses one and three were confirmed. Theoretical and practical implications of these results for the psychology of gambling are discussed.This study was supported by a grant from Loto-Québec.  相似文献   
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本文回顾了国内外学者对企业家和企业家精神的研究, 讨论了转型时期民营企业家的生成和企业的行为特点, 并基于企业家理论对政府提出了相关的宏观政策建议。  相似文献   
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应用多目标决策———理想点法 ,建立了一个综合评价学生数学成绩的数学模型  相似文献   
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一国的经济增长主要取决于技术进步、人力资本和制度创新等三个方面。技术进步是经济增长的驱动力 ,人力资本存量与质量是经济增长的关键 ,制度创新是经济增长的根源。此三者彼此密切关联、互动互进、共同推动经济增长  相似文献   
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In this article, we contend that the field of psychology has largely failed to foreground the role of gender in its study of immigration. Here, we review studies that address gender and migration focusing on the experience of children and adolescents. We provide developmental perspectives on family relations, well‐being, identity formation, and educational outcomes, paying particular attention to the role of gender in these domains. We conclude with recommendations for future research, which include the need to consider whether, and if so, how, when, and why it makes a difference to be an immigrant, to be from a particular country, or to be female rather than male. We argue that it is important to consider socioeconomic characteristics; to consider resilience as well as pathology; and to work in interdisciplinary ways to deepen our understanding of the gendered migratory experience of immigrant origin youth.  相似文献   
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高新技术的成长发育离不开风险投资以及政府、市场的引导 ,离不开基础研究与人力资源的开发 ,更需要引进大量的资金及国外的先进技术 ,同时其发展也与传统产业的提升有着密不可分的关系 ,因此发展高新技术产业应在妥善处理好这些关系上下功夫  相似文献   
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This paper studies how an overall fuzzy preference relation can be constructed in the compensatory context of the simple additive difference model, when imprecision on the trade-offs has to be taken into account. Three credibility indices of preferences are analysed and illustrated by a numerical example. Arguments are presented supporting the use of the third index, for which an interesting transitivity property (which was an open problem) is proved.  相似文献   
10.
提出一个反相流动注射-化学发光法同时测定Cr(Ⅵ)Gr(Ⅲ)的方法,基于皮素-H2O2-Cr(Ⅵ)-KOH化学发光反应直接测定Cr(Ⅵ);Cr(Ⅲ)在PbO2柱氧化后测定.方法简单,快速,检测限为1.0×10-9Cr(Ⅵ),线性范围为1.0×10-8~1.0×10-6g/mlCr(Ⅵ),用于淮河水样分析,结果满意.  相似文献   
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