Improvement of Surface Morphology of Yttrium-Stabilized Zirconia Films Deposited by Pulsed Laser Deposition on Rolling Assisted Biaxially Textured Substrate Tapes

The surface morphology of buffer layer yttrium-stabilized zirconia （YSZ） of YBa2CuaO7-σ （YBCO） high temperature superconducting films relies on a series of controllable experimental parameters. In this work, we focus on the influence of pulsed laser frequency and target crystalline type on surface morphology of YSZ films deposited by pulsed laser deposition （PLD） on rolling assisted biaxially textured substrate tapes. Usually two kinds of particles are observed in the YSZ layer： randomly distributed ones on the whole film and self-assembled ones along grain boundaries. SEM images are used to prove that particles can be partly removed when choosing dense targets of single crystalline. Lower frequency of pulsed laser also contributes to a smoother film surface. TEM images are used to view the crystalline structure of thin film. Thus we can obtain a basic understanding of how to prepare a particle-free YSZ buffer layer for YBCO in optimized conditions using PLD. The YBCO layer with nice structure and critical current density of around 5 MA/cm2 can be reached on smooth YSZ samples.

Application of artificial slope stability evaluation of improved response surface method in Donggang Power Plant

The study of artificial slope stability has been a key item of geological engineering projects. Though more evaluation methods are available,result of stability evaluation simulation does not explain the actual problem owing to the diversified geological engineering factors and complexity. The author made a detailed study based on surveys of large amount of geological engineering research on Donggang Power Plant slope project,discussed the comprehensive factors influencing the project,and gave analytical calculation and evaluation to the improved response surface of the slope project. The study result shows that the slope is stable,which can provide scientific basis for designing the slope.

Detecting surface freeze/thaw states in Northeast China with passive microwave data using an improved standard deviation method

Passive microwave remote sensing datasets are widely used to observe surface freeze/thaw(F/T)states.However,current algorithms are highly affected by snow cover and complex land cover types,compromising their performance.Therefore,this study proposes an improved algorithm for daytime detection of diurnal F/T states by using Advanced Microwave Scanning Radiometer 2 data.In the daytime F/T discrimination algorithm,a microwave spectral gradient index is applied to divide the surface into snow-covered and snow-free areas.In the snow-free area,the surface temperature index is optimised to improve the accuracy of the standard deviation method(SDM)in evaluating the accuracy of the F/T state.For the nighttime dataset,the microwave standard deviation index difference values between day and night are used to detect the F/T states based on the daytime results.The accuracy of the improved algorithm reaches 88.6%and 84.5%in the daytime and at nighttime,respectively.Compared with the SDM,the accuracy is improved by 10.2%in the daytime and 5.4%at nighttime.The results demonstrate that the proposed model is able to effectively distinguish the F/T states of snow-covered surfaces.Optimising the surface temperature index can significantly improve the accuracy of the SDM.The results reveal that the proposed surface F/T detection algorithm can be applied to regions with complex land cover types.

Postprocessing treatments to improve the laser damage resistance of fused silica optical surfaces and SiO_2 coatings

The combination of deep wet etching and a magneto-rheological finishing （MRF） process is investigated to simultaneously improve laser damage resistance of a fused-silica surface at 355 nm. The subsequently deposited SiO2 coatings are researched to clarify the impact of substrate finishing technology on the coatings. It is revealed that a deep removal proceeding from the single side or double side had a significant impact on the laser-induced damage threshold （LIDT） of the fused silica, especially for the rear surface. After the deep etching, the MRF process that followed does not actually increase the LIDT, but it does ameliorate the surface qualities without additional LIDT degradation. The combination guarantee both the integrity of the surface＇s finish and the laser damage resistance of the fused silica and subsequent SiO2 coatings.