共查询到11条相似文献,搜索用时 46 毫秒
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"环境试验与观测"专业2007年工作布置会暨专家组成立会议,是环境试验与观测专业的一次盛会.这次会议,一是专业主管全面总结2006年度的工作,部署2007年度的工作;二是第一次成立了环境试验与观测专业的专家组;三是科工委、各军工集团公司、研究机构和委属高校的领导和专家齐聚一堂,共谋专业发展大计.充分体现了科技与质量司以科学发展观和"四个"坚持为指导,深入贯彻落实国防科技工作会议精神,促进环境试验与观测专业又好又快发展的明晰思路. 相似文献
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三十多年前人民科学家钱学森以前瞻的战略性目光看到了沙漠发展的前景,指出"21世纪是科学利用沙漠的世纪,要换个角度看沙漠"并提出第六次产业革命,首创沙产业概念,在"不毛之地"上发展新兴产业。经过几十年的努力,我国在钱学森理念的指导下已成功将科技创新应用到沙区建设、大农业开发中,走出了一条西部沙区的绿色发展之路。 相似文献
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<正>一种与杂草相提并论且其貌不扬的麻风树草,如今能摇身一变使非洲变成"生物油田"吗?能源专家认为,一切事在人为。关键还要寄希望于外国企业的投资和农民阶层的意识革命。 相似文献
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《Atmospheric Environment. Part A. General Topics》1993,27(5):669-678
Four soil samples, collected in the central Namib Desert, were fractionated by dry sieving and aerosol generation into 16 size fractions in the range 0.15–300 μm diameter. The mass-size function of each soil and the dust (mineral aerosol) generated from the soil were studied. Due to the preferential lifting of smaller soil particles by the air stream, the soil underwent strong physical fractionation resulting in the bulk of the dust being found in the range of 1.3–10.3 μm, whereas the bulk of the soil was found in the range 63–300 μm. The concentrations of 11 elements in eight soil size fractions (from <45 to >300 μm) obtained by dry sieving were measured by X-ray fluorescence analysis while the concentration for these elements in eight size ranges (from <0.15 to >10.3 μm) obtained by aerosol generation were determined by particle-induced X-ray emission. The concentrations of the elements Al, Si, K, Rb and Sr were found to vary by less than a factor of two throughout the particle size range studied. However, the concentration of the elements Ca, Ti, Mn, Fe, Y and Zr increased when the particle size decreased below 150 μm to reach a maximum around 63-45 μm and then to decrease. The concentrations of the elements in the generated aerosol particles were found to be more similar to those in the bulk soil than any particular size fraction. For the aerosol size fraction, elemental enrichment factors were calculated with respect to the composition of average crustal rock, average soil, the bulk Namib soil and the small size fraction of the Namib soil. For several elements, the enrichment factors varied quite significantly, depending on the choice of the reference material. The elemental ratios in the mineral aerosol were also compared to those in the atmospheric aerosol from the Namib Desert. It was confirmed that there is a marine contribution for S, Cl and Sr in the Namib natural aerosol. The composition of the mineral aerosol generated in this study should be useful in source apportionment studies for the Namib Desert and sorrounding regions. 相似文献
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目的 对比分析海岸沙漠与干热沙漠的环境特征。方法 基于对温度、湿度、太阳辐射等典型环境要素的极值、月变化、累计作用日和日变化等的对比研究,掌握2类沙漠环境特征的差异。结果 湿热海岸沙漠常年高温年平均气温接近30℃,最高气温达到47.2℃。干热沙漠环境月温度变化明显。湿热海岸沙漠环境高温累计作用时间长,日最高温超过35℃的天数为190d。受海洋气候的影响,湿热海岸沙漠湿度比干热沙漠高约10%,因此湿热海岸沙漠更容易出现结露的现象。湿热海岸沙漠月辐射量均维持在较高水平,而干热沙漠在冬季月总辐射急剧降低。2种沙漠环境的年均降水量均较小,海岸沙漠环境略大于干热沙漠环境,干热沙漠环境年降水量波动不大。受海洋气候的影响,海岸沙漠环境降水量年分布差异极大。结论 湿热海洋大气作用下的海岸沙漠环境酷热,且高温持续时间极长,湿热海岸沙漠环境中使用的产品需加强耐极端高温和长期高温的环境适应性设计,高分子材料更易变形。相比于干热沙漠,湿热海岸沙漠湿度更高,更易出现结露的现象,金属材料更易发生腐蚀。湿热海岸沙漠总辐射比干热沙漠高,高分材料易发生老化,寿命降低。受海洋气候影响,海岸沙漠降水量年分布差异极大,湿热海... 相似文献
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以色列的沙漠治理与水资源利用 总被引:4,自引:0,他引:4
本文介绍了以色列在治理沙漠、水资源管理与立法方面的具体实践,特别介绍了以色列为治理沙漠、改善环境所采取的三种主要方法。文章还介绍了以色列同中国方面的合作情况。 相似文献
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本文从可持续发展的角度出发,以河西走廊为例分析了荒漠生态景观背景下城市发展所存在的问题,探讨了在河西走廊实现城市可持续发展的对策和建议。 相似文献
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独一无二的大沙漠撒哈拉沙漠位于非洲北部,东临红海,南部到达苏丹和尼日尔河河谷;西起大西洋海岸,北部以阿特拉斯山脉和地中海为界,处在250毫米等雨线(约北纬14。线)以北,是世界上最大的沙漠。"撒哈拉"是阿拉伯语"大荒漠"一词的音译。 相似文献