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831.
832.
Yu. F. Yurovsky 《Bulletin of the Crimean Astrophysical Observatory》2007,103(1):24-29
Observations of the solar eclipse on March 29, 2006, at the Laboratory of Radio Astronomy of the CrAO showed that the radio radius of the Sun at a wavelength of 1 m in the direction of the first contact was R d = 1.12 R ⊙ during solar activity minimum between cycles 23 and 24. The brightness temperature of the undisturbed Sun was T d = (0.6 ± 0.06) × 106 K. There was a noise storm source above the sunspot group NOAA 0865 whose bright nucleus had a size of 1′.3 and a brightness temperature T b = 16 × 106 K. The noise storm bursts were emitted from the region of the bright nucleus above the group NOAA 0865 and were absent during its covering by the disk of the Moon. Thermal radiation from a coronal condensation with a brightness temperature of (1?2) × 106 K extending out from the visible solar disk to 2′.7 was observed during the eclipse above the eastern limb sunspot group NOAA 0866. The bright nucleus in this limb source appeared 42 min after eclipse termination and persisted in the ensuing days. This may be indicative of the time of its emergence from behind the radio horizon formed by regular refraction of radio waves in the corona. The refractive displacement was measured by comparison with the eclipse observations at a shorter wavelength of 12 cm. Its value of 0′.96 is close to the calculated value of 0′.8. 相似文献
833.
834.
B. Fuchs D. Breitschwerdt M. A. de Avillez C. Dettbarn C. Flynn 《Monthly notices of the Royal Astronomical Society》2006,373(3):993-1003
We present a new unbiased search and analysis of all B stars in the solar neighbourhood (within a volume of 400 pc diameter) using the Arivel data base to track down the remains of the OB associations, which hosted the supernovae (SNe) responsible for the Local Bubble (LB) in the interstellar gas. We find after careful dereddening and by comparison with theoretical isochrones, that besides the Upper Scorpius the Upper Centaurus Lupus and Lower Centaurus Crux subgroups are the youngest stellar associations in the solar neighbourhood with ages of 20–30 Myr, in agreement with previous work. In search for the 'smoking gun' of the origin of the LB, we have traced the paths of the associations back into the past and found that they entered the present bubble region 10–15 Myr ago. We argue that the LB began to form then and estimate that 14–20 SNe have gone off since. It is shown that the implied energy input is sufficient to excavate a bubble of the presently observed size. 相似文献
835.
通过分析2010年6月28-29日发生在准噶尔盆地西北缘的一次大到暴雨天气,揭示了形成这次强降水天气的环流背景特点、物理量和雷达回波特征。结果显示:冷暖气团在克拉玛依地区附近相遇产生的中尺度锋生现象触发了本次暴雨天气过程。表现最明显的特征是:高空槽移动缓慢,中层切变线不断南压、低层中尺度系统维持,冷暖气团在该区域强烈交汇。暴雨区雷达速度场有明显的风场幅合。对流降水云团强度、移向变化的预测,是此类天气临近预报的关键和难点。 相似文献
836.
Many tools that are helpful for evaluating emissions mitigation measures, such as carbon abatement cost curves, focus exclusively on cost and emissions reduction potential without quantifying the direct and indirect impacts on stakeholders. The impacts of climate change will be the most severe and immediate for billions of poor people, especially for those whose livelihoods are based on agriculture and subsistence activities and are directly dependent on weather patterns. Thus, equity and vulnerability considerations must be central to GHG emissions reduction strategies. A case study of a carbon abatement cost curve for an electricity system in two Nicaraguan rural villages is presented and is complemented with assessments based on the poverty metrics of the poverty headcount, the Gini coefficient, and the Kuznets ratios. Although these metrics are relatively easy to calculate, the study provides a general indication as to how the social impacts of mitigation strategies on the poor (whether they are in rural or urban environments, developed or developing countries) can be revealed and highlights the inequalities that are embedded in them. Further work analysing how mitigation measures affect the various more detailed poverty indices, such as the Human Development, Gender Equality, or Multidimensional Poverty indices, is needed. 相似文献
837.
Geneviève Cloutier Florent Joerin Catherine Dubois Martial Labarthe Christelle Legay Dominique Viens 《Climate Policy》2013,13(4):458-474
Involving a wide-range of stakeholders at different moments in the planning of urban adaptation to climate change can help to overcome different barriers to adaptation, such as a lack of common perception, or control over options. This Article argues for an approach that involves a wide range of actors throughout the planning process in order to confront the challenges of urban adaptation to climate change. It builds on the results of a three-year participatory action research project to identify the catalysts with which local administrations can overcome the lack of data, the low level of engagement around the climate issue, and the cause-and-effect linkages of climate change impacts on the urban environment. Significant factors include territorial rootedness, leveraging actors’ experience, interaction between actors, as well as the valuing of local actors as experts of territorial management rather than as novices with regard to climate change adaptation. In addition to contributing towards the engagement of a large number of stakeholders around adaptation issues, a planning process that involves representatives from various sectors and during several stages contributes to a greater understanding of these issues and their linkages. It follows that such a process will bring changes to urban practices by better articulating local concerns about climatic issues.Policy relevanceAlthough participation is commonly advocated in policy responses to climate change, only few empirical studies have investigated the ways in which local actors' knowledge can be integrated into climate change adaptation planning processes. The article builds on the results of an action research project carried out in Québec City, Canada, to address the relevance of involving a progressively broader range of actors as the adaptation process moves through its various phases. Given that a multitude of barriers to adaptation are at play at different times in a municipality, collaborations between local stakeholders emerge as a key factor. These collaborations provide greater insight into the linkages between climate change impacts and the urban environment and, in doing so, bring into question ordinary urban management and design practices. 相似文献
838.
《Climate Policy》2013,13(1):813-828
A novel approach is described for limiting transport emissions through a cap-and-trade emissions trading scheme, whereby local governments would be the participants of emissions trading. It is proposed that emissions trading for passenger road transport has the effect of channelling the carbon costs away from fuel prices to land use costs. A ‘municipal emissions trading scheme’ could achieve this—local governments would have to cover vehicle traffic emissions generated by homes, businesses and industry on their territory. Municipalities are able to participate in an emissions trading scheme because they have planning control over development on their territory, and could control the amount of future vehicular traffic. Through planning, municipalities have access to a wide range of strategies to minimize transport emissions. Municipal emissions can be calculated as a share of total national road transport emissions with the help of a gravity model of traffic attraction. A municipal emissions trading system would result in capping and controlling passenger road transport emissions, not through raising fuel prices or importing credits, but by enforcing prudent and climate-efficient urban planning practices. 相似文献
839.
840.
通过对香港居民本地旅游消费行为的调查与访谈发现,家庭群体是本地旅游市场的消费主力,因此,本地居民虽然在单次旅游消费上表现为中低水平,但旅游活动的频率次数、人数规模都相当可观,同样成为了旅游目的地消费群体的主力构成。同时,居民本地旅游活动表现出自助活动为主、意愿偏好明显等消费行为特征,由此对旅游产品开发、公共交通设施、市场宣传营销以及旅游发展的社会公平都提出了不同于外地游客的要求,目的地的旅游发展必须在上述方面进行针对性地组织安排,才能实现对本地旅游消费市场的开拓发展,从而促成目的地旅游发展经济性和公平性的共同实现。 相似文献