The timing of formation of the low‐gradient, internally drained landscape of the Tibetan Plateau is fundamental to understanding the evolution of the plateau as a whole. Well‐dated sedimentary records of internal drainage of rivers into lakes are used to reveal the timing of this evolution. Here we redate the youngest continental sedimentary successions of central Tibet in the Lunpola Basin and propose a new age range of ca. 35 to 9 Ma, significantly younger than previously thought. We demonstrate long‐standing internal drainage in central Tibet since the late Eocene and stable sedimentary environments, source regions, and low topographic relief since at least the early Miocene. We suggest that sediment aggradation of internal drainage and reduction of hillslope gradients by erosion dominate the formation of low‐relief landscapes and that the late Cenozoic drainage basins in central Tibet developed in response to flow in the lower crust and/or mantle lithosphere.

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The electromagnetic relay, which has mechanical structure and break/make contacts, is affected by vibration and shock environment greatly. Contact wear and failure will be result from serious mechanical conditions. The samples used in this study were relays consisting two spring sets connected with armature component. Simulation results for a variety of vibration levels, frequencies, and shock levels are presented. Thereafter main factors and threshold conditions which influencing contact reliability were determined by the modal analysis and the harmonic response analysis and transient response analysis. The vibration and shock characteristics of movable parts within relay were also obtained by using high speed camera PhantomV7.3 10000fps , thus the mechanism of contact failure is revealed clearly. In addition, the characteristics of contact resistance were investigated when relay working in the mechanical environment. The results are valuable in modeling characteristics degradation and contact failure evaluation caused by mechanical environment for electromagnetic relay.

Chitosan membrane exhibited a good visible light photocatalytic activity over tetracycline hydrochloride degradation. The corresponding degradation mechanism was investigated as shown above.