飞机尾迹增暖效应显著

飞机留下的凝结尾迹只能持续几个小时,但如今它们的分布是如此之广,以至于其变暖效应超过了自莱特兄弟首次飞行以来,飞机释放并在大气中累积的所有二氧化碳所引起的全球变暖。更严重的是,德国大气物理研究所研究人员发现,到2050年,这种非二氧化碳变暖效应将增加2倍。"

观点分裂现象中的定律

早在2006年,加拿大医生、自称“先知”的Bill Deagle就曾声称飞机尾迹被故意装入了一种外星的致病的硅基生命。他警告说:“这是一种像蜜蜂或蚂蚁一样具有智慧并且会反击的硅基生命体。”尽管没有证据表明硅基生命的存在,Deagle的说法还是在社交媒体上不断出现。2023年3月,脸书上的一篇相关帖子获得了超过37000个赞和33000次分享,以及大量的赞同评论。

飞机后面为何拖“白烟”

人们经常可以看到，飞机在天空飞行时，有时后面会拖出一条或数条“白烟”，好像长长的飘带，悬挂在天空，久久不散。这种现象称为“飞机拉烟”。

UNSTEADY AERODYNAMIC MODEL OF ISOLATED ROTORIN LARGE-AMPLITUDE MANEUVERS

To improve the rotor off-axis response prediction, aerodynamic models must include the wake distortion effects of the maneuvering rotor. And the crux of the matter is to obtain a precise wake curvature parameter KR. A Peters-He finite-state wake model is improved to incorporate the operating-state-dependent KR to embody maneuver-induced effects. The curvature parameter KR varies with rotor forward speed, thrust and maneuvering angular rate according to a smoking experiment. Moreover, aerodynamic force/moment experiment indicates that after a quasi-step angular input, both on-axis and off-axis rotor responses show that an overshoot and its amplitude increases with the pitching rate. The comparison between theoretical and experimental results shows that the operating-state-accurate curvature parameter must be adopted to obtain accurate aerodynamic forces/moments, especially for the off-axis response. Additionally, combined with a dynamic wake distortion model, the obtained correlation agrees well with experimental data.

地震云真的存在吗

流言:天空出现了形似放射状条纹图案的云朵,有网友说这是"地震云",预示着将要发生地震。地震云的说法在网上流传甚广,到底存不存在地震云?真相:从气象观测的专业角度分析,可将网上给出的各种地震云归类为以下几种典型的云状,即透光高积云、絮状高积云、卷积云以及残留的飞机尾迹。所谓的地震云与地震没有任何关系。