共查询到18条相似文献,搜索用时 343 毫秒
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大约四十多亿年以前,我们的地球在浩瀚的银河中诞生了。与旁边的那些喷洒着耀眼光芒的星球相比,它是如此的朴素无奇,在远离太阳1.5亿公里的地方默默成长着。又几十亿年过去了,地球上已经是沧海桑田,气候变得温暖湿润,各种动植物在这块宇宙的沃土上旺盛地生长着,继续着生生不息的代谢过程。生于大地,死归泥土。终于,人类出现了,地球以宽阔的胸襟接纳了我们这些万物的灵长。它以丰富的出产供给我们衣 相似文献
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一、环境与环境问题什么叫环境?环境是以人类为中心的所有一切客观事物的总和。环境对人类生存的重要性:在太阳系的九大行星中,只有地球上有生物有人类,为什么?因为地球这样的环境适宜生物和人类的生存,或者说地球提供了生物和人类生存和发展的物质基础;地球离太阳距离适中,地球的自转也比较适度,地壳变迁相对稳定,地球的气候适合生物生存。地球外层有一层臭氧层,可以吸收太阳射来很大部分的紫外线,保护了生物和人类。地球的形成大约已有45亿年的历史,它不是一开始就有这样的环境。地球开始时是没有生命的,经过漫长的演变才适宜于生物生存,到了大约32亿年前才开始出现生命。5~6亿年前出现大量的生物,真正出现 相似文献
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环境安全是人类生存的必要条件人类和其他生物共同生活在我们这个蓝色的星球上,地球为我们提供了生存所必需的阳光、空气、水和衣食住行的必须物品。生物的进化和人类的聪明才智极大的利用、开发,改变了地球环境,使人类的生存条件不断的发展进步,走向文明和现代化,地球环境不断的为人类造福,为人类的可持续生存提供支持。但是,人类在开发利用地球环境的同时却给环境造成了极大的污染和破坏。环境污染公害事件使发生地的方圆数十公里内成为不毛之地,迫使当地的人离乡背井、重新寻找生存环境的事例,在历史上曾多次发生。据有关资料统计,20世纪初至70年代中期的70年间,世界公害事件发生65起,公害病患者达 相似文献
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Imai Kaoru Hagi Akifumi Inoue Yasuhide Amarasiri Mohan Sano Daisuke 《Food and environmental virology》2020,12(2):180-190
Food and Environmental Virology - Human noroviruses are the major cause of non-bacterial acute gastroenteritis worldwide. Since no therapeutic agent has been proven to prevent human norovirus... 相似文献
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Akrum H. Tamimi Sheri Carlino Sarah Edmonds Charles P. Gerba 《Food and environmental virology》2014,6(2):140-144
The objectives of this study were to determine the movement of a virus throughout a household and the impact of an alcohol-based hand sanitizer (ABHS) on reducing the movement and exposure of the virus to household members. Bacterial virus MS-2 was used as the surrogate for human enteric and respiratory viruses. Seven households with families having at least two children in the age range of 2–18 living in the home were used in this study. The hands of one adult family member were contaminated with 1 × 108. MS-2 bacteriophage in each home. After 8 h, the hands of each family member (10 fingers) and 20 frequently touched fomites were sampled to determine baseline contamination without intervention. Within 8 h, MS-2 was detected on all of the family member’s hands and most of the fomites. The intervention consisted of providing the families in all selected homes with bottles of an ABHS, which were placed in the kitchen, bathrooms, and nurseries. Smaller individual bottles were provided for each family member greater than 12 years old to place in purses, pockets, backpacks, etc. The families were instructed to use the ABHS one time or three times during the day. For one and three uses, a statistically significant reduction of virus on un-inoculated and inoculated hands of ~99 % occurred within 8 h. Similar reductions occurred on fomites throughout the households (97–99 %). These results demonstrate that the use of an ABHS can significantly reduce transfer of a virus to the hands, and to the commonly touched surfaces within the household. 相似文献
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环境保护是我国的一项基本国策,日益受到政府重视和人民群众的关注。文章分析过去一年来我国环境保护取得的成果以及当前仍面临的严峻形势,提出要通过在投资和空间布局体现生态文明建设要求;重点实施大气、水、生态建设工程;严格执法,创造人人自觉保护环境的外部氛围;转变思路,利用市场机制保护生态环境;加强能力建设,形成环境保护的长效机制几方面促进环境改善,实现天蓝地绿水清。 相似文献
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燃煤型倒焰窑排放的烟法浓度高,处理难度大,已成为大气治理中的新热点。采用实用新型燃煤机,改变煤的燃烧方式使其完全燃烧,从而使燃煤烟气污染得到有效的控制达标排放并节约能源。 相似文献