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The study of enclaves in granitic plutons provides fundamental information on the petrogenesis of their host rocks. Here we combine U–Pb zircon ages, petrography, geochemistry and Nd–Hf isotope composition to investigate the origin of dioritic–granodioritic enclaves and their host granodiorites and biotite granites in the Xuehuading–Panshanchong area, which is a pivotal site to study the Palaeozoic intracontinental orogenic processes of the South China Block. Obtained ages indicate that the host rocks were formed in early Silurian time (c. 432 Ma). The enclaves are fine grained, but with mineral assemblages similar to their hosts and contain amphibole, biotite and plagioclase. All rocks have fractionated rare earth element patterns ((La/Yb)N = 2.86–8.16), except for one biotite granite that has a concave rare earth element pattern ((La/Yb)N = 1.50). Most rocks are depleted in Ta–Nb–Ti, and have negative Eu anomalies and ϵNd(t) (–8.86 to –5.75) and zircon ϵHf(t) (–13.30 to –4.11, except for one, –39.08). We interpret that the enclaves were formed at the borders of magma-ascending conduits, where the mafic mineral crystallization was enhanced by rapid cooling. Conversely, the biotite granites were produced by fractional crystallization from a related granodiorite magma. The sample with a concave rare earth element pattern may have been influenced by hydrothermal fluid–melt interaction. Geochemical modelling suggests that the granodiorites were likely generated by disequilibrium melting of heterogeneous amphibolites in the middle–lower crust. Considering the geological data for the Palaeozoic magmatic rocks in the South China Block, we propose that the Xuehuading–Panshanchong magmatism was likely triggered by piecemeal removal of the thickened lithospheric root and subsequent thermal upwelling of mantle, without a mantle-derived magma contribution to the granites.

With the progress of informatization, the development of communication technology and the wide application of wide bandgap semiconductors represented by GaN, the application of GaN in 5G technology has received increasing attention. In this paper, various characteristics of GaN application in 5G technology were emphatically introduced and a detailed analysis of these characteristics was conducted on the basis of the GaN application in 5G technology via literature searching and combining what we have learned. In addition, the development and innovation of GaN power devices in recent decades and some problems encountered at the present stage were explained and a certain prediction of the GaN application in 5G technology were proposed that this area will be a great part of industry in 21th century.

The various stages of tectonic activity associated with the Dongwu movement (DM) and the associated sedimentary responses in the Sichuan Basin, Southwest China, have been analyzed and their significance for petroleum geology discussed. The analysis was based on the comprehensive analysis of field outcrops, wells, and seismic data. It is proposed that the DM in the Sichuan Basin can be divided into four stages: (1) Stage I occurred during the late Qixia, when the Emeishan mantle plume (EMP) began to rise, causing a fall in relative sea level, leading to subaerial exposure and a subaqueous hiatus. This formed a ramp paleogeographic pattern that was higher in the southwest and lower in the northeast of the basin. (2) Stage II, which occurred during the middle and late Maokou, sees the NE-SW-trending extensional rifting being affected by the EMP, developing from an early localized platform trough to the late widely distributed basin facies in the northern part of the basin. (3) Stage III occurred at the end of the Maokou, when the EMP caused continuous rapid uplift, resulting in a significant fall in relative sea level and a distinct karstification and paleogeomorphological pattern. This led to weakly denudated areas in the southwestern basin, moderately to strongly denudated areas in the southern and central basin, and basically no denudated areas in the northern basin. (4) Stage IV, at the beginning of the Late Permian, was marked by large-scale basaltic eruptions, the activation of basement faults, and hydrothermal modification. These four stages of tectonic activity in the basin reflect the entire evolutionary process of the EMP from its initial weak stage to its strong climax. The four stages, on the one hand, led to the differentiation of sedimentation and provided conditions for diagenesis, thus controlling the development and evolution of reservoir and source rocks. On the other hand, the reactivated faults would have had a significant impact on hydrocarbon migration and accumulation. This study therefore provides a valuable reference for the study of other mantle plume areas around the world.

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