Critical and steady-state characteristics of delay propagation in an airport network.

In this work, we established a density equation for delayed airports to investigate the horizontal propagation mechanism of delays among airports in an airport network. We explored the critical conditions, steady-state features, and scale of the delay propagation, and designed a simulation system to verify the accuracy of the results. The results indicated that, due to the no-table scale-free feature of an airport network, the critical value of delay propagation is extremely small, and delays are prone to propagate among airports.

[Morphological traits of indigenous field carps maintained in traditional rice-based farming systems.].

Rice-fish is an important traditional farming system. In the rice-fish system, common carp (Cyprinus carpio) is the major species raised in paddy field where the environment is characterized by shadow water. Under a long-term of natural selection and artificial selection, the carp would adapt to the paddy field environment.