Search

Abstract An approach has been developed to produce silver nanoparticles (AgNPs) rapidly on semiconductor wafers using electrochemical deposition. The closely packed AgNPs have a density of up to 1.4 × 1011 cm-2 with good size uniformity. AgNPs retain their shape and position on the substrate when used as nanomasks for producing ultrahigh-density vertical nanowire arrays with controllable size, making it a one-step nanolithography technique. We demonstrate this method on Si/SiGe multilayer superlattices using electrochemical nanopatterning and plasma etching to obtain high-density Si/SiGe multilayer superlattice nanowires.

Associative learning strategy (ALS) is an important means of acquiring vocabulary--especially in L2 learning. This study proposes a method to identify the associative learning mechanism based on complex network theory. First, a distributed association strategy (DAS) for the associative learning of L2 learners based on distributed language learning is analyzed, and a dynamic vocabulary network model based on DAS is constructed. Second, by analyzing the topological parameters, the external form and overall characteristics of the vocabulary network and three questions regarding its impact on vocabulary acquisition are discussed. A case study involving the foreign language learning and teaching of undergraduate students is used to illustrate this method. The results show that the proposed method can effectively reflect the associative learning process of acquiring vocabulary. Results also reveal the dynamic and evolutionary laws governing vocabulary networks when using ALS, as well as small world and scale-free characteristics.

The manufacturing process of high-strength and ultra-thin copper foil is characterized by complex processes, strong coupling between phases, and multiple factors affecting the product quality. The quality control technology and related quality control system which are oriented to the manufacturing process will be an important guarantee for achieving efficient and stable production. A design scheme of multidimensional quality control system was proposed to address the shortcomings of current copper foil manufacturing enterprises in terms of technology and software systems related to the stability and quality control of high-strength and ultra-thin copper foil manufacturing process. By analyzing the copper foil manufacturing process and its quality control requirements, an integrated control system framework based on a three-layer architecture was established. On this basis, the connotation and functions of each subsystem were designed from three aspects i.e. product quality control, intelligent process quality assurance, and production line operation quality monitoring, providing assurance for the efficient, stable, and intelligent production of high-strength and ultra-thin copper foil. This paper also provides a reference for research and development of independent industrial software in the field of quality control. [ABSTRACT FROM AUTHOR]

Polyoxometalate-based metal–organic frameworks (POMOFs) have received wide attention in supercapacitors and H2O2 detection due to their possession of the rich redox active sites of polyoxometalates (POMs) and the ordered structure of metal–organic frameworks (MOFs). In this study, we successfully synthesized a host–guest Cu3[P2W18O62]@HKUST-1 (HRBNU-7) compound by a grinding method. Cu3[P2W18O62] successfully entered the HKUST-1 pores as confirmed by the results of infrared (IR) spectroscopy, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The specific capacitance of HRBNU-7 is 318.6 F g−1 at 1 A g−1 in a three-electrode system using nickel foam as the collector. The specific capacity retention is 92.36% after 5000 cycles. The assembled symmetrical supercapacitor (SSC) achieved a high energy density of 10.58 W h kg−1 at a power density of 500.00 W kg−1. In addition, HRBNU-7 exhibits excellent electrochemical detection of H2O2, including a wide linear range of 0.5 μM–0.3 mM, a low detection limit of 0.17 μM, and excellent selectivity and stability, and it can be effectively utilized for the analysis of H2O2 content in actual serum samples. These excellent properties are attributed to the unique redox activity of Cu3[P2W18O62] and the high specific surface area of HKUST-1. This work offers a strategy for exploring POMOFs as electrode materials in supercapacitors and electrochemical sensors. [ABSTRACT FROM AUTHOR]