水中爆炸对围岩增耦的实验研究

为研究水中爆炸对围岩的增耦,在一个直径1.6 m的水泥砂浆半球体装置上,将其中心预留的直径0.3 m的腔室内注水和置入水泥砂浆芯体,对比性地进行了一系列的1.00 g TNT （2,4,6—三硝基甲苯）当量的填实和空腔爆炸实验。水泥砂浆球表运动测量数据表明,与水泥砂浆中的空腔解耦相比,水中空腔爆炸的解耦效果较差,尤其水腔中爆炸可大大增强爆炸能量的耦合。可以推断,水下爆炸会明显增强围岩中的爆炸应力波强度,近水域中的空中爆炸也可能会增强围岩中的爆炸能耦合,因而相对于围岩和堤坝中同距离、同药量的爆炸来讲,所引起     

Effects of water treatments on the activation of soil seed banks - A case study on the lower reaches of the Tarim River

Evaluation of seedling emergence is a common method used to investigate the vegetation restoration potential of soil seed banks. Previous studies have primarily been conducted in the laboratory using a single water treatment. However, when this method is used, it is difficult to optimize the water conditions for the needs of the individual species of seeds. Additionally, the germination conditions for seedlings in the laboratory are different from those in nature. To avoid these issues, we conducted experiments to activate soil seed banks in the field using different water treatments. The results revealed that: (1) generally, the number of species and quantity of seedlings decrease gradually as the water supply decreases, but that for several species most seedlings did not appear when they were provided with the greatest amount of water, and (2) different species present different germination characteristics. According to the rate of seedling emergence, the species were classified into two germination types: fast and slow. In addition, each species also had a unique climax period of emergence, which was delayed with a decrease in water supply. Therefore, the amount of water provided is vital to seedling emergence, and various water treatments should be evaluated when studying the characteristics of different species in soil seed banks. For the lower reaches of the Tarim River, the optimal soil moisture for seedling emergence ranged from 23% to 28%, and seedling conservation should be strengthened during the climax period of emergence (9-15 days from the day when water became available). These results highlight the importance of the use of an optimal water treatment and demonstrate the danger of using a single treatment method. Our results also emphasize the need for a preliminary study prior to conducting studies to evaluate seed banks.