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171.
绿色旅游产业发展模式与运行机制   总被引:10,自引:0,他引:10  
通过介绍国外绿色旅游产业发展的指导方针及非政府组织的行为.结合苏格兰酿酒工业旅游与北京蟹岛生态农业旅游中发展绿色旅游的经验总结.分别提炼出绿色工业旅游的运作模式和绿色农业旅游的发展模式。在此基础上.提出要通过构建由观念、牡会经济体制与科学技术三个层次形成的保障体系.来保证绿色旅游经济的正常运转。最后.从绿色旅游产业地域与行业选择、绿色保障制度体系建立、赢利机制构造和绿色旅游消费者培育等四个方面提出了我国绿色旅游产业发展的行动纲领。  相似文献   
172.
The present research examines whether collective guilt for an ingroup's collective greenhouse gas emissions mediates the effects of beliefs about the causes and effects of global warming on willingness to engage in mitigation behavior. In Study 1, we manipulate the causes and effects of global warming and then measure collective guilt. Results demonstrate that collective guilt for Americans' greenhouse gas emissions is stronger when participants believe that global warming is caused by humans and will have minor effects. Study 2 employs the same manipulations and then measures collective guilt and collective anxiety, as well as willingness to conserve energy and pay green taxes. This study replicates the effect from Study 1 and rules out collective anxiety as a plausible alternative mediator. Collective guilt for Americans' greenhouse emissions was the only reliable mediator of the effect of beliefs about global warming on willingness to engage in mitigation behaviors. The importance of collective guilt as a tool for promoting global warming mitigation is discussed.  相似文献   
173.
汞和两种农药复合污染对土壤转化酶活性的影响   总被引:7,自引:0,他引:7       下载免费PDF全文
通过模拟方法研究了豆磺隆,呋喃丹2种农药与重金属汞(Hg)单一及复合污染对草甸棕壤和黑土4个土壤转化酶活性的影响.结果显示,在试验浓度范围内,土壤添加豆磺隆和呋喃丹后,转化酶变化幅度分别为-12%~7%和-6%~7%,表明2种农药对土壤转化酶的毒性较小;Hg对转化酶最大抑制率为22%~35%,二者之间呈显著的对数负相关关系,表明Hg对转化酶的毒性较大,转化酶在一定程度上可作为Hg污染的监测指标,通过对数方程计算出4个土样的生态剂量(ED50)分别为76.68,727.49,236.52,316.59mg/kg;Hg和2种农药之间普遍存在交互作用,豆磺隆与Hg复合污染引起土壤转化酶最大净变化量(△I)为对照的-12%~15%,呋喃丹和Hg为-25%~-6%,有机质对复合污染产生的毒性有明显的缓冲作用.  相似文献   
174.
Abstract

A formulation containing the biopesticide azadirachtin‐A (AZ‐A), extracted from the seeds of neem tree, Azadirachta indica A. Juss, was applied (10 μg/mL) in a nutrient solution (200 mL) to the roots of young spruce trees [Picea glauca (Moench) Voss]. The uptake, translocation, persistence and dissipation of AZ‐A in spruce were studied. The insecticide was taken up by the root system, translocated via xylem vessels and accumulated in the photosynthate sinks (areas of new growth, especially shoots), confirming that AZ‐A is systemic. The peak AZ‐A concentrations (μg/g, fresh weight) in the shoots (5.16 ± 0.73) and needles (2.56 ± 0.31) occurred at 8 and 15 d after treatment, respectively. The AZ‐A concentrations in bark and wood during this period were very low, however they were high in the root samples. The dissipation of AZ‐A from the shoots was rapid compared to other matrices. The initial (0‐d) and final (20‐d) AZ‐A concentrations (μg/mL) in the nutrient solution were 8.99 ± 1.24 and 3.24 + 0.55, respectively. The dissipation of AZ‐A in the nutrient solution followed first‐order kinetics. Dissipation half‐life (DT50) and rate constant (C), calculated from the nonlinear regression equation (Y = 8.400 e‐00544t), were 12.74 d and 0.0544, respectively. Usefulness of AZ‐A as a systemic insecticide in forest insect control programs is discussed.  相似文献   
175.
For a community to manage hazards successfully, those who are responsible for planning and implementing responses to a disaster threat situation must understand the social and economic realities of populations at risk. A random sample survey of residents in the vicinity of a US Army chemical weapons storage depot in Alabama confirms that those in the lowest quartile of household income (i.e., less than US $25,000 in 1999) differ in important ways from the rest of the sample. Using economic status as a grouping variable resultedin identifying a concentration of individuals with special needs. This group differed significantly from the remainder of the sample as to demographic and attitudinal characteristics, hazard knowledge and concerns, emergency preparedness, and emergency decision-making and their likelihood of taking protective actions. Respondents in the lowest income quartile reported greater restrictions in physical abilities, fewer community contacts, a heightened concern about area hazards, and limited resources for taking preparedness and response actions.  相似文献   
176.
从事故统计分析结果表明,90%以上的事故是由操作者违章作业造成的。因而提出了安全预案预控活动的有效方法,并介绍了实现这一方法的阶段及效果。  相似文献   
177.
Many simulations of collective behavior have been presented in recent years. Recently, a pioneering study by [Ballerini et al., 2008a] and [Ballerini et al., 2008b] suggested that the interactions of birds in a flock should be modeled using the topological distance rather than the metric distance. The concept of topological distance is deemed important for explaining collective behavior. However, few studies have discussed the distinctions between the metric and topological distances. In this paper, we clarify the difference between models based on the topological and metric distances and propose a new hybrid model of these models. The agent of our model switches between these two interactions by tuning the threshold parameters. We show that this hybrid flocking model has the medium property between the metric and the topological distance. In other words, the agents of our hybrid model can dramatically make and divide flock by tuning their neighborhoods. This result suggests that making and dividing flock would be deeply connected with animal's cognition.  相似文献   
178.
The paper presents an analysis of the effect of magnetic fields of power frequency generated by heavy-current electric equipment on the environment. The results of computation and measurements of the magnetic field in the vicinity of power busducts are included. Possible hazards are considered that result from the effects of the magnetic field on workers present in the vicinity of busducts as well as secondary hazards caused by the degrading effect of the magnetic field on ferromagnetic structural materials (in reinforced concrete structures). Attention is given to an ergonomic aspect of interaction of the magnetic field with cathode ray tube computer monitors (annoying oscillation of the image).  相似文献   
179.
180.
Using two very different empirical settings, this paper emphasizes the required conditions for the successful crafting of sustainable institutions. In the first setting, different farmer groups in Cambodia and Vietnam try to establish a collective approach for small-scale community-based aquaculture and fail. In the second setting, the collective initiatives of urban women in India are analysed. The Indian women succeed in their objective of a fuel transition from firewood to gas cookers using a cooperative approach. Ostrom's variables identified in the “Multitier Framework for Analyzing Social–Ecological Systems (SES)” (Ostrom, 2007) are applied to local collective action initiatives in both settings to understand which factors make some of the groups succeed in their objectives and others fail. This research highlights the complexity as well as the uniqueness of different SESs. At the same time, the paper contributes to demonstrating the usability of the SES and certain variables to estimate the likelihood of success of self-organisation and crafting of rules. It highlights the relevance of certain conceptual variables for sustainable or unsustainable outcomes for different cases.  相似文献   
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