Based on the principle that the present is the key to the past , detailed analyses, such as AMS 14 C dating, grain size, component and morphology of heavy minerals, micro-morphology of zircon, Rb/Sr, magnetic susceptibility and total organic carbon (TOC), were conducted to identify paleoflood sediments archived in Zhongba Site. The results indicate that the plaeoflood sediments bear great similarities with modern flood sediments in the following aspects: (1) probability cumulative curves mainly show a pattern of 3-4 segments; (2) grain-size distribution of suspended matter ranges between 3 and 10Ф; (3) the sediments are well-sorted, most of which are suspended matter (>50%); (4) the same species, quantity and morphology of heavy minerals; (5) scanning electronic microscope images show that shapes of zircon are mainly oval and nearly spheral, rounded due to long-distance transport; (6) higher Rb/Sr values (0.55 -0.66)than those of sediments from cultural layers (0.03-0.26); (7) magnetic susceptibility values (133.73 -433.05 10 -6 m 3 /kg) are lower than those of sediments from cultural layers (959.25 -2442.44 10 −6 m 3 /kg); (8) TOC (0.14% -0.33%) are lower than those of sediments from cultural layers (1.13%-2.95%). Our results demonstrate that, except for the 1981 flood, there are at least six paleoflood events that occurred during the Qing

Daniel K. Inouye Solar Telescope (formerly known as Advanced Technology Solar Telescope) will be the largest optical solar telescope ever built to provide greatly improved image, spatial and spectral resolution and to collect sufficient light flux of Sun. To meet the requirements of the telescope the design adopted a 4m aperture off-axis parabolic primary mirror with challenging specifications of the surface quality including the surface figure, irregularity and BRDF. The mirror has been completed at the College of Optical Sciences in the University of Arizona and it meets every aspect of requirement with margin. In fact this mirror may be the smoothest large mirror ever made.This paper presents the detail fabrication process and metrology applied to the mirror from the grinding to finish, that include extremely stable hydraulic support, IR and Visible deflectometry, Interferometry and Computer Controlled fabrication process developed at the University of Arizona.

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The Software Configurable Optical Test System (SCOTS) uses deflectometry to measure surface slopes of general optical shapes without the need for additional null optics. Careful alignment of test geometry and calibration of inherent system error improve the accuracy of SCOTS to a level where it competes with interferometry. We report a SCOTS surface measurement of an off-axis superpolished elliptical x-ray mirror that achieves <1 nm root-mean-square accuracy for the surface measurement with low-order term included. © 2015 Society of Photo-Optical Instrumentation Engineers (SPIE)