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1.
In recent years, the study of polarisation vision in animals has seen numerous breakthroughs, not just in terms of what is known about the function of this sensory ability, but also in the experimental methods by which polarisation can be controlled, presented and measured. Once thought to be limited to only a few animal species, polarisation sensitivity is now known to be widespread across many taxonomic groups, and advances in experimental techniques are, in part, responsible for these discoveries. Nevertheless, its study remains challenging, perhaps because of our own poor sensitivity to the polarisation of light, but equally as a result of the slow spread of new practices and methodological innovations within the field. In this review, we introduce the most important steps in designing and calibrating polarised stimuli, within the broader context of areas of current research and the applications of new techniques to key questions. Our aim is to provide a constructive guide to help researchers, particularly those with no background in the physics of polarisation, to design robust experiments that are free from confounding factors.  相似文献   

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Adult tabanid flies (horseflies and deerflies) are terrestrial and lay their eggs onto marsh plants near bodies of fresh water because the larvae develop in water or mud. To know how tabanids locate their host animals, terrestrial rendezvous sites and egg-laying places would be very useful for control measures against them, because the hematophagous females are primary/secondary vectors of some severe animal/human diseases/parasites. Thus, in choice experiments performed in the field we studied the behavior of tabanids governed by linearly polarized light. We present here evidence for positive polarotaxis, i.e., attraction to horizontally polarized light stimulating the ventral eye region, in both males and females of 27 tabanid species. The novelty of our findings is that positive polarotaxis has been described earlier only in connection with the water detection of some aquatic insects ovipositing directly into water. A further particularity of our discovery is that in the order Diptera and among blood-sucking insects the studied tabanids are the first known species possessing ventral polarization vision and definite polarization-sensitive behavior with known functions. The polarotaxis in tabanid flies makes it possible to develop new optically luring traps being more efficient than the existing ones based on the attraction of tabanids by the intensity and/or color of reflected light.  相似文献   

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This paper reviewed recent research in environmental governance as a response to environmental challenges at various spatial, temporal and administrative scales. It documented the shift of approach from regulation to governance, and attempted to provide a comprehensive understanding why and how the transformation occurred. It also described major factors and forces of environmental governance, and discussed research advance in environmental governance theory. Finally, this paper summarized recent research findings on environmental governance in China, and listed policy recommendation for enhancing the governance.  相似文献   

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The relative importance of taste and vision for methiocarb-induced food aversions was studied in captive house finches (Carpodacus mexicanus). Seed handling behavior and patterns of consumption of safflower seeds treated with methiocarb indicated that taste was not involved. Rather, the data suggest that, in the absence of visual cues to palatability, the finches responded to physiological effects following methiocarb ingestion. In an experiment to assess the effect of an added visual signal, pairs of finches given methiocarb-treated hulled oats with red tape on their food bowl showed more aversion to the treated food than did pairs without tape. These and other findings suggest that methods to reduce bird damage to crops with chemical repellents should emphasize visual cues rather than taste.  相似文献   

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Climate change is a global phenomenon that affects biophysical systems and human well-being. The Paris Agreement of the United Nations Framework Convention on Climate Change entered into force in 2016 with the objective of strengthening the global response to climate change by keeping global temperature rise this century well below 2 °C above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5 °C. The agreement requires all Parties to submit their “nationally determined contributions” (NDCs) and to strengthen these efforts in the years ahead. Reducing carbon emissions from deforestation and forest degradation is an important strategy for mitigating climate change, particularly in developing countries with large forests. Extensive tropical forest loss and degradation have increased awareness at the international level of the need to undertake large-scale ecological restoration, highlighting the need to identify cases in which restoration strategies can contribute to mitigation and adaptation. Here we consider Brazil as a case study to evaluate the benefits and challenges of implementing large-scale restoration programs in developing countries. The Brazilian NDC included the target of restoring and reforesting 12 million hectares of forests for multiple uses by 2030. Restoration of native vegetation is one of the foundations of sustainable rural development in Brazil and should consider multiple purposes, from biodiversity and ecosystem services conservation to social and economic development. However, ecological restoration still presents substantial challenges for tropical and mega-diverse countries, including the need to develop plans that are technically and financially feasible, as well as public policies and monitoring instruments that can assess effectiveness. The planning, execution, and monitoring of restoration efforts strongly depend on the context and the diagnosis of the area with respect to reference ecosystems (e.g., forests, savannas, grasslands, wetlands). In addition, poor integration of climate change policies at the national and subnational levels and with other sectorial policies constrains the large-scale implementation of restoration programs. The case of Brazil shows that slowing deforestation is possible; however, this analysis highlights the need for increased national commitment and international support for actions that require large-scale transformations of the forest sector regarding ecosystem restoration efforts. Scaling up the ambitions and actions of the Paris Agreement implies the need for a global framework that recognizes landscape restoration as a cost-effective nature-based solution and that supports countries in addressing their remaining needs, challenges, and barriers.

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Mitigation and Adaptation Strategies for Global Change - The article Globally regional life cycle analysis of automotive lithium-ion nickel manganese cobalt batteries written by Jarod C. Kelly,...  相似文献   

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Critical methodological challenges in the microbial biosensor approach to assessing Hg(II) bioavailability were evaluated from the perspective of analytical chemists. The main challenge stems from the fact that the chemical speciation of Hg(II) in natural waters exerts a major control on its bioavailability, yet its natural complexation equilibria are extensively altered during conventional bioassays. New data, obtained using a bioluminescent Hg(II)-biosensor, that illustrate these challenges are presented and potential solutions proposed.  相似文献   

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传统方法使用固定的波长吸收指数来估算地壳元素或棕碳吸光,但该方法只能处理仅存在两种组分的情形(黑碳/棕碳,或黑碳/地壳元素)的吸光贡献,存在较大不确定性.为此,本文提出一种新的方法,利用武汉在线观测数据(2021年2、3、8、9月),采用铁作为地壳元素的示踪物,利用最小相关系数法(MRS)得出地壳元素的吸光贡献,在扣除地壳元素吸光之后,再得到黑碳吸光增强系数(Eabs).结果显示观测期间370nm波段地壳元素吸光贡献均值为12.3%,月均值范围5.7%~15.5%,且波长吸收指数与铁的浓度正相关,表明地壳元素吸光贡献不可忽视.地壳元素吸光贡献呈现出显著的季节特征,呈现出冬季低,春季高的特点.地壳元素吸光的分离前后计算的Eabs存在一定的差异,受到了黑碳和铁的相关性的影响.观测期间扣除地壳元素吸光后,Eabs均值为1.43±0.53,在季节性上呈现春夏高,秋冬低的特性,春季较高Eabs值与春季黑碳较高的老化程度有关.Eabs对无机盐和有机物的含量存在正的依赖关系,证明了这些包裹物质对吸光增强的影响.  相似文献   

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This paper reviews the factors influencing the development and sustained operation of regional industrial symbiosis (IS) networks and discusses the roles a coordination body can play to alter these factors so as to catalyse the development and functioning of such networks. These are analysed within the context of experiences gained in the early stages of three regional IS programmes under development in the UK, and of the recently launched national IS programme (NISP) that they are part of. It is stated that the policy framework in the UK has elements supportive of such networks to evolve, and the regional public bodies are favouring their development. Based on differences among studied cases, it is argued that the nature of companies’ operations and industrial history in the regions, the extent of peer pressure, the positioning of the coordinating body in the region, and its approach to awareness raising and recruitment have major influence on the progress of the programmes. Finally, the paper emphasises the importance of aligning the characteristics of emerging operations with the longer-term sustainability requirements. If accepted, this challenge assigns additional responsibilities to the coordinating parties.  相似文献   

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某 6 0 0MW四角切圆燃烧锅炉 ,采用顶部燃尽风系统并配合使用偏转二次风系统 ,炉膛下部二次风大角度正切 ,上部二次风和OFA风反切消旋 ,在炉膛截面水平方向和炉膛高度方向形成分级燃烧 .运行结果表明 ,该燃烧器布置方式能抑制炉内结渣 ,减轻炉膛出口扭转残余并能降低NOx 排放量 .通过工况试验 ,将锅炉的氮氧化物排放水平降低到国家标准限定值以下 .采用数值计算对该炉炉内流动、传热、燃烧和氮氧化物生成过程进行模拟  相似文献   

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Making the concept of Reducing Emissions from Deforestation and Degradation (REDD+) ready to be a mechanism to combat tropical deforestation and associated greenhouse gas (GHG) emissions by compensating developing countries for income foregone in reducing their rates of deforestation, requires solutions for outstanding controversies. Existing opinions on REDD+ vary greatly. By using the Q-method as part of an action research approach, this paper investigates experts’ attitudes towards REDD+. Based on their responses to 41 statements, four attitudinal groups were identified, characterized as pragmatists, sceptics, conventionalists and optimists. Opinions between groups differed as to the level of application, credibility, eligibility, economic effectiveness, and public acceptability of REDD+ policy instruments. Three of the four groups were supportive of international REDD+ type policy interventions, but there was disagreement on the more concrete design issues of REDD+ projects, such as the allocation of responsibilities, the distribution of burdens and benefits, and whether or not co-benefits could be expected, or should be required. As the potential of REDD+ is shaped not only by international climate policy but also by national and regional policies and stakeholder perceptions, this paper suggests that participatory forms of decision-making may help to develop tailor-made solutions that are supported by the many different actors that are necessarily involved in REDD+ projects.  相似文献   

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In the face of a changing climate, many United States (US) local governments are creating plans to prepare. These plans layout how a community is vulnerable to existing and future changes in climate as well as what actions they propose taking to prepare. The actions included in these plans provide insight into what local governments feel they have the ability to undertake, as well as what actions they believe are important to building resilience. To date, little to no analysis has been conducted on the content of these plans, leaving researchers, practitioners, and those supporting communities with limited understanding of what gaps need to be filled or how best to support locally prioritized climate action. This paper analyzes the content of 43 stand alone climate adaptation plans from US local communities to identify the types of actions proposed and how those actions compare to what researchers indicate the communities should be prioritizing based on regional climate projections. The results indicate that local communities include numerous and varied actions in their adaptation plans and that the majority of communities are selecting actions that are theoretically appropriate given projected changes in regional climate. Yet some types of actions, such as building codes and advocacy, are not being widely used. These results contrast with previous studies, which found that local communities focus primarily on capacity building approaches. Findings also demonstrate that plans rarely contain significant details about how actions will be implemented, raising questions about whether plans will translate into real-world projects.  相似文献   

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The use of strobe lights and strobe light-bubble curtain combinations were evaluated as behavioral guidance systems to reduce impingement via avoidance behavior by estuarine fish. White perch (Morone americana), spot (Leiostomus xanthurus) and menhaden (Brevoortia tyrannus) were tested in an experimental flume for avoidance to strobe lights, bubble curtains and strobe light-bubble curtain combinations at different water velocities, strobe flash rates and light acclimation (light and dark). The possible accommodation of fish to strobe light was also tested using a microcomputer and on-line biomonitoring chamber examining alterations in breathing rates over time. Avoidance of strobe light ranged from 8–36% for white perch, 8–100% for spot and 8–68% for menhaden depending on the conditions tested. Statistical analyses indicated significant avoidance by white perch at most flash rates with a 0.2 ms−1 flow rate and at 120 and 300 flashes min−1 with 0.3 and 0.5 ms−1 flows. Spot had significant avoidance under most conditions. Menhaden had significant avoidance for all flash rates at 0.2 ms−1 flows and for 300 and 600 flashes min−1 at flows of 0.3 and 0.5 ms−1. All species exhibited little avoidance of bubble curtains alone. Strobe light-bubble curtain combinations had avoidance results of 3–58% for white perch, 21–85% for spot and 9–81% for menhaden. Spot and menhaden exhibited significant avoidance for most conditions at 0.2 and 0.5 ms−1 flows. White perch had significant avoidance for most conditions at 0.2 ms−1 flows, but no avoidance at 0.5 ms−1. The biomonitoring system indicated that little, if any, accommodation took place during 24 h. Strobe light and strobe-bubble curtain combinations elicited the highest avoidance results at flash rates ≥300 min−1 and low water velocities. Strobe light systems may reduce impingement rates but must be evaluated on site specific needs and conditions.  相似文献   

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某600MW四角切圆燃烧锅炉,采用顶部燃尽风系统并配合使用偏转二次风系统,炉膛下部二次风大角度正切,上部二次风和OFA风反切消旋 ,在炉 膛截面水平方向和炉膛高度方向形成分级燃烧。运行结果表明,该燃烧器布置方式能抑制炉内结渣,减轻炉膛出口扭转残余并能降低NO x排放量。通过工况试验,将锅炉的氮氧化物排放水平降低到国家标准限定值以下,采用数值计算对该炉炉内流动、传热、燃烧和氮氧化物生成过程进行模拟。  相似文献   

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