Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract: In the context of global climate change, heat waves, extreme precipitation, extreme droughts and storm surges have increased in most areas of the Belt and Road, which seriously threatens the personal and property safety of countries along the Belt and Road. This study focuses on dealing with the issues associated with the risk identification and assessment of extreme climate events in the “Belt and Road” region, including the coarse or single assessment scale and weak response strategies. It develops a multi-scale extreme climate risk assessment framework, and completes the risk assessment of four representative extreme climate events including heat waves, extreme precipitation, extreme droughts, and storm surges at three scales of 1 km, 100 m, and 10 m. The risk assessment results reveal the spatial distribution, temporal dynamics, and major influencing factors of the 4 types of extreme climate risks in the Belt and Road region. The better understanding of these can provide scientific support for more reasonable and effective response to disasters, reduction and transfer of risks, and reduction of personal and property losses.
Subjects: Materials Science >> Materials Science (General) submitted time 2017-04-10 Cooperative journals: 《材料研究学报》
Abstract:依据铝电解阴极炭块结构的非匀质特性,将其看作由炭骨料和沥青粘合剂组成的多相复合材料,从细观结构的角度研究了钠的扩散过程。采用Matlab编写不同炭骨料粒度组成和含量的随机圆、椭圆、多边形骨料投放模型程序,得到七种阴极炭块细观结构模型图片,并以igs模型文件形式导入ANSYS建立了二维有限元数值模型。依据扩散方程和热传导方程的相似性,采用ANSYS的热分析单元对钠扩散过程进行模拟求解,分析了炭骨料粒度组成、含量和形貌对钠扩散过程的影响。结果表明,与炭块中沥青相比,炭骨料对炭块中的钠扩散的阻碍作用更大,炭骨料颗粒圆度越小、骨料粒度组成越小、含量越高,则钠的扩散速率越低。对于粒度组成为0.003~0.006 m、含量为80%的圆形炭骨料模型,钠的扩散速度最低;模拟结果与试验结果有较好的一致性,证明了模拟的精确性和可靠性。