An environmentally-friendly vacuum reduction metallurgical process to recover germanium from coal fly ash
An environmentally-friendly vacuum reduction metallurgical process to recover germanium from coal fly ash
复制标题
从粉煤灰中回收锗的环保真空还原冶金工艺
DOI：
10.1016/j.jhazmat.2016.03.025
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发表时间：
2016
影响因子：
13.6
通讯作者：
Xu Zhenming
中科院分区：
文献类型：
--
作者：
Zhang Lingen;Xu Zhenming
星星沙丘是世界沙海中最大的风成底形，通常分布在特定的地理区域内，具有多向风场。然而，相对较少的研究集中在环境因素，赋予这么大的沙子，这些沙丘。具体而言，通过长期监测来验证星星沙丘的发展过程是稀缺的。在这项研究中，通过观察三维气流场和长期的沙丘动力学，我们演示了地形障碍物，产生垂直气流和局部空气循环，控制星星沙丘的发展在鸣沙山，中国敦煌。结果表明，地形引起的气流停滞和偏转是形成星星沙丘的主要机制之一。在我们的研究中，地形障碍有助于发展以东风为主的强烈垂直气流。这种强烈的垂直气流是巨型沙丘向上生长的主要驱动机制之一。垂直气流是现有的风成地貌资料中最强的气流。此外，星星沙丘通常分布在当地空气环流较强的地区。长期沙丘动力学研究结果表明，局地环流与区域风场形成三个风向，对星星沙丘的维持和发展起着重要作用。我们的研究表明，复杂的巨型沙丘是地形障碍的产物，这有利于他们在风沙地貌识别。介绍了在局部环境和地形障碍影响下的星星沙丘演化新模式。
Star dunes, the largest aeolian bedforms in the sand seas of the world, are usually distributed within specific geographical areas that have multi-directional wind regimes. However, relatively few studies have focused on the environmental factors that impart such great volumes of sand to these dunes. Specifically, verification of the developmental processes of star dunes through long-term monitoring is scarce. In this study, by observing 3-D airflow fields and long-term dune dynamics, we demonstrate how topographic barriers, which generate vertical airflow and local air circulation, control the development of a star dune on Mingsha Mountain in Dunhuang, China. Results show that airflow stagnation and deflection caused by topography is one of the major mechanisms for the formation of star dunes. In our study, topographic barriers contribute to the development of intensive vertical airflow dominated by easterly winds. This intensive vertical airflow is one of the main driving mechanisms of the upward growth of mega-dunes. Vertical airflow is the strongest developed airflow reported in available data on aeolian geomorphology. In addition, star dunes are usually distributed in areas where the local air circulation is strong. The results of long-term dune dynamics verify that local air circulation, which forms three wind directions with the regional wind regime, contributes to the maintenance and development of star dunes. Our study indicates that complex mega-dunes are products of topographic barriers, which facilitate their recognition in aeolian geomorphology. We introduce a new evolution pattern of star dunes under the influence of local environment and topographic barriers.