Measurements of cirrus clouds with a three-wavelength lidar

A three-wavelength lidar system is set up. The backscatter signals of 355, 532, and 1 064 nm are mea- sured simultaneously to derive the optical depth, lidar ratio, and backscatter color ratio of cirrus clouds, respectively. The lidar configuration and the data processing are described. The case study shows that the optical depths of cirrus clouds are not dependent on wavelength while the backscatter color ratios are.     

复杂网络可控性的研究概况

 近年来,随着复杂网络研究的不断深入,人们越来越关注于对复杂网络终极目标的探索,即如何对复杂网络进行控制。如同一辆构造精密且复杂的汽车,人们对汽车的驾驶和操控只需通过档位、油门、刹车和离合这样几个简单的部件即可(如图1 所示),那么对于一个节点连边众多的网络,我们也希望通过少量的外界输入来控制整个网络的运行状态,使网络的运行结果为我们所用。例如在电力网络中,如何对个别节点进行外界输入来达到调控整个网络的性能;在基因网络中,如何有选择地对某些节点进行外界输入或者干预来达到调控整个基因网络,从根本上实现对一些疾病的治愈等。