Forchheimer方程作为非达西渗流中广泛应用的基本方程之一,方程中A、B系数的确定一直是孔隙介质渗流领域中的热点及难点,不同学者根据渗流试验结果提出了不同的Forchheimer方程A、B系数的经验公式,但对于均质以及混合粒径的非均质条件...Forchheimer方程作为非达西渗流中广泛应用的基本方程之一,方程中A、B系数的确定一直是孔隙介质渗流领域中的热点及难点,不同学者根据渗流试验结果提出了不同的Forchheimer方程A、B系数的经验公式,但对于均质以及混合粒径的非均质条件下评价各经验公式适用性的研究较少。因此在渗流阻力试验的基础上,采用归一化目标函数和线性回归法评价了Forchheimer方程经验公式的适用性,为不同孔隙介质条件下Forchheimer方程经验公式的选取提供参考。结果表明:对于均质孔隙介质,Sidiropoulou公式对水力梯度有着很好的预测效果;对于2种混合粒径孔隙介质,在使用平均粒径的基础上,还应考虑混合粒径的质量比和大小因素,Macdonald公式的预测效果受混合粒径的质量比和大小影响较小,Kadlec and Knight公式对于水力梯度的预测结果较为稳定;对于5种混合粒径孔隙介质,使用d60作为特征粒径进行预测的效果较好,Kadlec and Knight公式对于系数A的预测效果较好,Ergun公式对于系数B的预测效果较好。研究结果能够为工程中均质及非均质松散砂砾石孔隙介质渗流计算的Forchheimer方程的选取提供依据。展开更多
Through its media logic, which is defined by programmability, pervasiveness, connectivity, and datafication, WeChat establishes a non-linear, interactive, and user-dominated media environment. This media logic enhance...Through its media logic, which is defined by programmability, pervasiveness, connectivity, and datafication, WeChat establishes a non-linear, interactive, and user-dominated media environment. This media logic enhances the influence of each user within WeChat’s narrative landscape and revolutionises traditional media narration methods by enabling them to generate and distribute content. In such an environment, users are able to edit, receive, and send information without constraints of time or distance, which enables delayed interactions that broaden the potential for human communication and dissemination. Additionally, WeChat partially replaces social behaviours and institutions, thereby modifying their original structures and characteristics. As individuals become more accustomed to this media environment, they progressively adjust to the forms that are appropriate for media representation on WeChat, thereby completing the mediatization of culture and society. In this process, individuals are becoming more dependent on media and media logic, with WeChat’s influence permeating social and cultural activities through its media logic. This interaction has a substantial impact on society and culture, thereby aiding in their reconstruction.展开更多
文摘Forchheimer方程作为非达西渗流中广泛应用的基本方程之一,方程中A、B系数的确定一直是孔隙介质渗流领域中的热点及难点,不同学者根据渗流试验结果提出了不同的Forchheimer方程A、B系数的经验公式,但对于均质以及混合粒径的非均质条件下评价各经验公式适用性的研究较少。因此在渗流阻力试验的基础上,采用归一化目标函数和线性回归法评价了Forchheimer方程经验公式的适用性,为不同孔隙介质条件下Forchheimer方程经验公式的选取提供参考。结果表明:对于均质孔隙介质,Sidiropoulou公式对水力梯度有着很好的预测效果;对于2种混合粒径孔隙介质,在使用平均粒径的基础上,还应考虑混合粒径的质量比和大小因素,Macdonald公式的预测效果受混合粒径的质量比和大小影响较小,Kadlec and Knight公式对于水力梯度的预测结果较为稳定;对于5种混合粒径孔隙介质,使用d60作为特征粒径进行预测的效果较好,Kadlec and Knight公式对于系数A的预测效果较好,Ergun公式对于系数B的预测效果较好。研究结果能够为工程中均质及非均质松散砂砾石孔隙介质渗流计算的Forchheimer方程的选取提供依据。
文摘Through its media logic, which is defined by programmability, pervasiveness, connectivity, and datafication, WeChat establishes a non-linear, interactive, and user-dominated media environment. This media logic enhances the influence of each user within WeChat’s narrative landscape and revolutionises traditional media narration methods by enabling them to generate and distribute content. In such an environment, users are able to edit, receive, and send information without constraints of time or distance, which enables delayed interactions that broaden the potential for human communication and dissemination. Additionally, WeChat partially replaces social behaviours and institutions, thereby modifying their original structures and characteristics. As individuals become more accustomed to this media environment, they progressively adjust to the forms that are appropriate for media representation on WeChat, thereby completing the mediatization of culture and society. In this process, individuals are becoming more dependent on media and media logic, with WeChat’s influence permeating social and cultural activities through its media logic. This interaction has a substantial impact on society and culture, thereby aiding in their reconstruction.