共查询到20条相似文献，搜索用时 93 毫秒
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由于云南独特的地理环境,造就了其丰富的湿地资源,这些湿地资源具有多样性、特殊性与显著性。随着人们对保护湿地重要性的认识逐渐加深,云南湿地资源已经得到了较好的管理与保护,与此同时也有一些问题突显出来。通过对云南湿地的类型及基本特征的分析,对云南湿地资源的研究,针对云南湿地环境所面临的威胁,提出了云南湿地资源的保护和可持续利用的对策。 相似文献
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文章以玉溪城市湿地资源保护与修复规划为研究对象,在分析现状湿地资源的基础
上,探讨玉溪市湿地保护与修复的空间格局,分析玉溪湿地生态核、湿地生态节点、湿地生态廊
道等方面的规划策略和实施措施,促进城市生态的良性发展。 相似文献
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《世界热带农业信息》2018,(2)
正国家林业局日前公布了全国64处湿地开展国家湿地公园试点名单,海南4个湿地公园试点上榜,其中包括海口五源河湿地公园、海口美舍河湿地公园。同时,海南新批准建立的5个省级湿地公园,全部集中在海口。根据《海口市湿地保护修复总体规划》,全市将全面加强湿地资源保护和实现湿地资源的可持续利用,改善人居环境质量,建设50余个湿地公园和小区,朝着"湿地城市"的目标迈进。 相似文献
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湿地是自然界最富生物多样性的生态系统之一，与社会发展及人类福祉关系密切。近些年，由于我国经济发展带来的气候变化及人类活动的过度影响，湿地正面临着面积减少、功能减弱、多样性降低等问题。伴随着生态文明建设成为社会主义建设的重要支柱，湿地生态修复工作也得到了重要的制度保障。结合湿地属性及政策保障有针对性地对湿地进行保护与修复，对区域的湿地保护及生态环境建设具有重要意义。从湿地恢复理论及湿地恢复原则入手，阐述了湿地恢复的主动恢复模式和被动恢复模式；从生境恢复技术、生物恢复技术、土壤修复技术、水文修复技术、植被恢复研究、案例分析等方面介绍了湿地恢复的技术及案例，最后提出了出台政策、湿地恢复重塑、湿地旅游资源利用及湿地保护的创新机制试点等湿地保护的重点措施建议。 相似文献
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本文综述了西溪国家湿地公园的动植物资源现状,以及西溪湿地综合保护工程在建立生物多样性保护体系和构建生态景观中的积极工作,并在此基础上提出进一步保护和修复的措施。 相似文献
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Segregation of form, color, movement, and depth: anatomy, physiology, and perception 总被引：63，自引：0，他引：63
Anatomical and physiological observations in monkeys indicate that the primate visual system consists of several separate and independent subdivisions that analyze different aspects of the same retinal image: cells in cortical visual areas 1 and 2 and higher visual areas are segregated into three interdigitating subdivisions that differ in their selectivity for color, stereopsis, movement, and orientation. The pathways selective for form and color seem to be derived mainly from the parvocellular geniculate subdivisions, the depth- and movement-selective components from the magnocellular. At lower levels, in the retina and in the geniculate, cells in these two subdivisions differ in their color selectivity, contrast sensitivity, temporal properties, and spatial resolution. These major differences in the properties of cells at lower levels in each of the subdivisions led to the prediction that different visual functions, such as color, depth, movement, and form perception, should exhibit corresponding differences. Human perceptual experiments are remarkably consistent with these predictions. Moreover, perceptual experiments can be designed to ask which subdivisions of the system are responsible for particular visual abilities, such as figure/ground discrimination or perception of depth from perspective or relative movement--functions that might be difficult to deduce from single-cell response properties. 相似文献
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Mansfield E 《Science (New York, N.Y.)》1980,209(4461):1091-1093
R & D, through its effects on the rate of productivity increase, can significantly restrain the rate of inflation in the medium and long run. High rates of inflation damage the workings of the price system and impair the efficiency of practically all economic activities, including R & D. Findings suggest that the percentage increase between 1969 and 1979, in total real R & D expenditures, has been exaggerated due to the inadequacy of the gross national product deflator as applied to R & D. 相似文献
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The primary rocks are a sequence of titanium-rich basic volcanics, composed of clinopyroxene, plagioclase, and ilmenite with minor olivine, troilite, and native iron. The soil and microbreccias are respectively loose and compacted mixtures of fragments and aggregates of similar rocks, minerals, and glassy fragments and spheres. Impact events are reflected by the presence of shock metamorphosed rock fragments, breccias, and glasses and their resulting compaction to form complex breccias, glass-spattered surfaces, and numerous glass-lined craters. Chemistry of the glasses formed by the impact events is highly variable, and the high iron and nickel content of a few moundlike features suggests that at least some of the projectiles are iron and nickel-rich meteorites. 相似文献
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Maslansky R 《Science (New York, N.Y.)》2003,301(5639):1479-82; author reply 1479-82
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