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Chinese loess deposits are some of the best continental records of palaeoclimatic and palaeoenvironmental changes in the late Cenozoic. Many investigations have shown that the long-time climate variations recorded by the loess-paleosol sequences can be correlated with global environmental changes. However, there are still some foundational questions concerning loess deposition that are not well answered, casting uncertainty on many previous conclusions, especially high-resolution palaeoclimatic records. In this study, three typical loess-paleosol sections spanning the last glacial cycle were closely sampled for optically stimulated luminescence (OSL) dating and palaeoclimate interpretation along a northwest-southeast transect in Chinese Loess Plateau. Results show that there is a 4-5 ka hiatus in the typical loess deposits, and as a consequence suggests that the loess record is not continuous over millennial time scales. As such, previous conclusions on climatic and environmental changes at millennial-centennial time scale, reconstructed through the loess record, should be reinvestigated. The erosional hiatus may be forced by a period with strengthened East Asian winter monsoon and the less vegetation cover in the investigated sites.

Thousands of Paleolithic artifacts have been recovered from Paleolithic sites in the Luonan Basin, in the upper South Luohe River of central China. Their discovery suggests that the basin was an important area for hominin settlement during the Pleistocene. However, the initial timing of this occupation and the environmental conditions for this period are still largely unknown. In addition, the sediments are not well dated and most of the artifacts lie on the surface. In an attempt to resolve these issues, a new systemic paleomagnetic analysis was carried out on the loess deposits that contain in situ stone tools. Our detailed loess–paleosol analyses of the stratigraphy of different sites in the basin and Chinese Loess Plateau shows the accumulation of the loess since at least 1.1 million years (Ma) ago. Moreover, recently discovered in situ cores, flakes and retouched stone tools in these deposits show that hominins used this region repeatedly from 0.8–0.7 Ma to 0.4–0.3 and 0.2–0.1 Ma. Pedostratigraphic analyses, magnetic susceptibility and carbon isotope analyses also indicate that these hominins lived in a subtropical to warm-temperate climate with broad-needle-leaf forest vegetation mixed with grasses.

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InZnO thin-film transistors using high-κ Ta2O5 gate dielectric are presented and analysed. The large capacitance coupling effect of amorphous Ta2O5 results in fabricated devices with good electrical properties. However, an anomalous negative threshold voltage (V th) shift under positive bias stress is observed. It is suggested that electron detrapping from the high-κ Ta2O5 dielectric to the gate electrode is responsible for this V th shift, which is supported both by the logarithmical dependence of the V th change on the duration of the bias stress and device simulation extracted trapped charges involved.

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