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This paper analyzed the strong motion characteristics based on 86 three-component strong motion records of the MW 6.6 Luding earthquake. Additionally, the factors that influence the variation in ground motion for three earthquakes with similar magnitude in Sichuan Province were investigated. The analysis result indicates a strong correlation between the observed ground motion parameters and the distribution of published Modified Mercalli Intensity. The residual analysis reveals that the spectral accelerations at periods 0.1–10.0 s are amplified to 0.0798–0.3057 times the mean level in the rupture forward direction and weakened to 0.0738–0.2831 times the mean level in the rupture backward direction. The maximum pulse direction recorded by the 51LDJ station is N6°E, aligning with the vertical fault direction. The velocity pulses has distinct bidirectional pulses in the waveforms, with a PGV of 37.0 cm/s. The source effect of the strike-slip MW 6.6 Luding and MW 6.5 Jiuzhaigou earthquakes on ground motion is relatively less significant compared to the average level of mainshocks in southwest China. However, the thrust-fault MW 6.7 Lushan earthquake exhibits a stronger source effect on ground motion during short and medium periods, but a weaker source effect during long periods when compared to the average level. The anelastic attenuation of the Longmenshan, Xianshuihe, and Huya fault zones in Sichuan exhibits significant regional variation and periodic correlation. This phenomenon is closely linked to the regional tectonic background variations and the heterogeneity of crustal structure within the area. [ABSTRACT FROM AUTHOR]

We compare and analyze the consistency of observed acceleration and velocity data recorded by accelerometer and seismometer simultaneously in five aspects: time series, 5% damped response spectra, the variation and distribution characteristics of peak value ratios and spectral acceleration ratios, and correlation analysis. The results show that these two have good consistency, especially in medium-frequency bands and medium- and far-fields. In the research dataset of ground motion prediction equations (GMPEs), we propose the weight ratios of the observed acceleration and velocity records and verify that the empirical weighted ratios are reasonable and reliable and applicable to southwest China. [ABSTRACT FROM AUTHOR]

Understanding sub-lethal effects of nanomaterial may be particularly important to determining ecosystem responses as current levels of nanomaterial release are low compared to levels projected for the future. In this work, the sub-lethal effects of water stable, nanocrystalline fullerenes as C 60 (termed nC 60 ) were studied on Scenedesmus obliquus , a globally distributed phytoplankton. Sub-lethal concentration for S. obliquus was firstly determined as 0.09 mg L −1 using the standard 72 h exposure tests (OECD Guideline 201). Subsequent sub-lethal experiment of nC 60 on the S. obliquus was carried out for 60 d and focused on the photosynthesis processes. The results demonstrate that upon sub-lethal exposure, the photosynthetic products of polysaccharide, soluble protein and total lipid were decreased with exposure time. The photosynthetic pigments of chlorophyll a and chlorophyll b were negatively impacted. Further investigations indicate that the decrements in photosynthetic products and pigments were mainly due to the algal Mg 2+ decrement (by 40%) at the sub-lethal concentration (0.09 mg L −1 ) of nC 60 . The decrement in Mg 2+ of S. obliquus was due to the inhibition of Mg 2+ -ATPase activity caused by nC 60 . Sum up, these results not only describe the sub-lethal effects but also provide the probably mechanism for sub-lethal effects of nC 60 on exposed S. obliquus . [ABSTRACT FROM AUTHOR]