Search

The adjustable conductance of a two‐terminal memristor in a crossbar array can facilitate vector‐matrix multiplication in one step, making the memristor a promising synapse for efficiently implementing neuromorphic computing. To achieve controllable and gradual switching of multi‐level conductance, important for neuromorphic computing, a theoretical design of a superlattice‐like (SLL) structure switching layer for the multi‐level memristor is proposed and validated, refining the growth of conductive filaments (CFs) and preventing CFs from the abrupt formation and rupture. Ti/(HfOx/AlOy)SLL/TiN memristors are shown with transmission electron microscopy , X‐ray photoelectron spectroscopy , and ab initio calculation findings corroborate the SLL structure of HfOx/AlOy film. The optimized SLL memristor achieves outstanding conductance modulation performance with linearly synaptic weight update (nonlinear factor α = 1.06), and the convolutional neural network based on the SLL memristive synapse improves the handwritten digit recognition accuracy to 94.95%. Meanwhile, this improved synaptic device has a fast operating speed (30 ns), a long data retention time (≥ 104 s at 85 ℃), scalability, and CMOS process compatibility. Finally, its physical nature is explored and the CF evolution process is characterized using nudged elastic band calculations and the conduction mechanism fitting. In this work, as an example the HfOx/AlOy SLL memristor provides a design viewpoint and optimization strategy for neuromorphic computing. [ABSTRACT FROM AUTHOR]

This study presents new zircon U–Pb ages, Sr–Nd–Hf isotopic data, and whole‐rock geochemical data obtained from the Early Cretaceous volcanic rocks from the north‐western Great Xing'an Range, Northeast China, to constrain the late Mesozoic magmatism and geodynamic setting of this region, which is located in the eastern segment of the Central Asian Orogenic Belt (CAOB). Zircon U–Pb age determinations show that the studied samples formed at 124–114 Ma with an Early Cretaceous magmatic event produced voluminous felsic and minor mafic volcanic rocks. The mafic rocks are dominantly basalt and basaltic andesite, with relatively low SiO2 contents (49.88–56.64 wt.%). These rocks are enriched in Th, U, large‐ion lithophile elements (LILE; e.g., Rb, Ba, and K) and light rare‐earth elements (REEs), and depleted in high‐field‐strength elements (HFSE; e.g., Nb, Ta, and Ti) and heavy REEs (Yb and Lu). The rocks have εNd(t) values of 0.44–0.75 and initial 87Sr/86Sr ratio of 0.70499–0.70548. These results indicate that the mafic rocks were derived from the partial melting of enriched lithospheric mantle that had been previously metasomatized by subduction‐related fluids and experienced variable amounts of fractional crystallization and moderate crustal contamination. In contrast to the mafic rocks, the felsic rocks are dominantly peraluminous trachytes, rhyolites, and dacites with high SiO2 contents and low MgO contents. These felsic rocks display enriched and variable concentrations of LILEs and REEs, show negative Eu anomalies, and have εHf(t) values of +2.6 to +8.3 with TDM2 ages of 1,014–655 Ma, indicating they were derived from partial melting of juvenile crustal materials. These Early Cretaceous igneous rock assemblages record a post‐collisional lithospheric extensional setting resulting from the closure of the Mongol–Okhotsk Ocean, consistent with the results of previous studies on the contemporaneous tectono‐magmatic activities in NE China. [ABSTRACT FROM AUTHOR]

By periodically inserting the higher migration barrier of oxygen vacancy (VO) in Al SB 2 sb O SB 3 sb atomic layer into HfO SB x sb , it gracefully controls the VO migration and the formation and rupture of conductive filaments. B Superlattice-Like Memristive Synapse b In article number 2201446, Xingsheng Wang and co-workers propose a HfO SB x sb /AlO SB y sb superlattice-like memristor and achieve controllable multi-level conductance switching in the electric synapse for neuromorphic computing. [Extracted from the article]

In this paper, we report on LA‐ICP‐MS zircon U–Pb dates of 14 Mesozoic volcanic rocks from the central Great Xing'an Range (CGXR). These data are integrated with the temporal and spatial distribution of local magmatism‐related Mesozoic mineralization, in an effort to develop an understanding of the geodynamic evolution of the region. Periodic magmatic events in the GXR date from ~1,703 through ~145 Ma. Mesozoic volcanism in the CGXR can be subdivided into three episodes: Triassic (250–205 Ma), Early–Middle Jurassic (182–165 Ma), and Late Jurassic–Early Cretaceous (155–115 Ma). A revision of the previously defined volcanic sequence is offered using a combination of our zircon U–Pb ages and published Mesozoic geological and geophysical evidence from northeast China. We propose that (a) Early–Middle Triassic volcanism in the CGXR resulted from subduction of the Paleo‐Asian oceanic plate; (b) Late Triassic volcanism was related to subduction of the Mongol–Okhotsk oceanic plate (especially near the Erguna Block) and subsequent extension after the closure of the Paleo‐Asian Ocean; (c) Early–Middle Jurassic volcanism was mainly controlled by the southward subduction of the Mongol–Okhotsk oceanic plate; (d) Late Jurassic–initial Early Cretaceous magmatism was initiated by closure of the Mongol–Okhotsk Ocean; and (e) late Early Cretaceous volcanism was induced following the final closure of the Mongol–Okhotsk Ocean and rollback of the Paleo‐Pacific oceanic plate. [ABSTRACT FROM AUTHOR]

Silicic volcanic rocks are the main components of the upper crust. Understanding their genesis can help us better understand the processes of crustal growth, reconstruction, and crust–mantle interactions. In this study, we examine silicic volcanic rocks from Suolun in the Great Xing'an Range, China. These silicic volcanic rocks are of Cretaceous age (140–123 Ma), with 68–76 wt% SiO2, and the majority are of the high‐K (calc‐alkaline) series. εHf(t) ranges between +1.7 and +9.9, mostly around 7. The Early Cretaceous silicic volcanic rocks from Suolun are cold‐wet‐oxidised, highly differentiated I‐type volcanic rocks, and plagioclase and K‐feldspar are the main fractionation phases. TTiZ shows that silicic magma undergoes a reheating process in the magma chamber, which causes the early rheological lock‐up magma to reactivate and thus drives it to further differentiation. This process is probably driven by the injection of high temperature magma at depth. The wet upwelling of the Mongol‐Okhotsk Oceanic plate in the deep resulted in large‐scale magmatism in the area. These results provide a possible explanation for the formation of highly differentiated magmatic rocks and further confirm the evolutionary link between volcanic rocks and plutonic systems. [ABSTRACT FROM AUTHOR]

BACKGROUND Jiuqu are vital saccharifying and fermenting agents for Chinese fermented foods. Natural ventilation during Jiuqu fermentation causes changes in temperature, oxygen and moisture content, resulting in mass and heat gradients from the outer to inner areas of Jiuqu blocks. In the present study, microbiota stratification in Jiuqu was investigated by single molecule real‐time sequencing and culture isolation. The contributors of Bacillus to amylase activity of Jiuqu and the dynamics of their biomass during Jiuqu fermentation were also analyzed. RESULTS: The dominant orders, genera and species between the inner and outer layers of Huangjiu qu (HJQ) were similar, although they displayed greater variance in two layers of Baijiu qu (BJQ). Bacillus possessed the highest diversity (including 27 species) in Jiuqu. Bacillus licheniformis, Bacillus altitudinis, Bacillus subtilis, Bacillus amyloliquefaciens and Bacillus megaterium were most prevalent in HJQ, whereas B. licheniformis, B. amyloliquefaciens and Bacillus cereus were dominant in BJQ. Isolates of B. amyloliquefaciens, B. subtilis and B. cereus exhibited high activities of amylase and glucoamylase. Quantification of Bacillus members possessing genes of α‐amylase revealed that B. cereus and B. licheniformis were the most dominant microbes to secret α‐amylase in Jiuqu and their biomass were increasing during Jiuqu fermentation. CONCLUSION: The present study demonstrates the microbial distribution in different layers of Jiuqu and clarifies the Bacillus species processing the activity of α‐amylase. These results will help industries control the quality of Jiuqu by rationally selecting starters and optimizing their microbiota. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]