In this paper, a novel bifunctional oxygen electrode, La2CuO4@Au, was synthesized using the sol-gel method. Thermogravimetry differential thermal analysis (TG-DTA) was used to analyze the formation mechanism and crystallization temperature. The crystal structure and surface morphologies of La2CuO4 were determined by X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The CV curves of 0.1M KOH electrolyte saturated with N2 and O2 showed that La2CuO4@Au had excellent catalytic activity for oxygen reduction reaction (ORR).

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This study presents the analogical assessment of the train-induced vibration and radiated noise in a proposed theater. The theater is to be constructed in a region with crowded metro lines, and the assessment is implemented in an analogical building with comparable structural type and metro condition. Prior to the assessment, the comparability of the analogical building with the theater is validated using the train-induced ground vibration. With the same horizontal distance from the metro line, the train-induced vibration level in the analogical building is 9 dB higher than that in the construction site of the theater. Such results indicate that the lack of soil layers may lead to a dramatic increase in train-induced vibration in the building. In the staircase of the analogical building, the train-induced radiated noise reached 55 dB (A), which is 10 dB (A) higher than the daytime allowable level. As the most important indicator, the noise rating number in the cinema of the analogical building is NR-43, which put forward an enormous challenge on the construction of the theater with a denoise demand of 23 dB. The analogical method applied in this study provides an effective and practical way for the assessment of train-induced vibration and radiated noise in proposed vibration-sensitive buildings. The assessment results that provide necessary reference and support for the anti-vibration design will help guarantee the stage effect of the theater.

Studies have shown that physical parameters such as size have obvious influence and relevance on the sound spectrum structure. In order to study the new detection technology of sound recognition of compaction of soil, this article conducted a large number of indoor soil sample hammering tests. The timbre features of the sound are extracted by the impact sound feature extraction method based on the principle of auditory perception, and the focus is on the correlation between frequency domain eigenvalues such as spectral centroid and different compaction of soil. By grouping and analyzing the multiple sets of acoustic samples after the different compaction of soil samples are excited, we found that the centroid feature of the subband spectrum can well represent the compaction of soil, and the two have a strong correlation; the maximum correlation coefficient is up to 0.81. The research results show that when the reasonable hammering force range of exciting soil is 30 N~89 N, the subband spectrum centroid feature is used as an index to characterize the compaction of soil, which can be used to infer the compaction of soil.

A novel cobalt-free La0.6Sr0.4Fe0.9Nb0.1O3 (LSFNb) cathode material was synthesized by a solid-state reaction. And BaCe0.7Zr0.2Sm0.1O3-α (BCZSm) electrolyte was prepared by a sol-gel method. Transmission Electron Microscopy (TEM) and Thermal Gravimetry Analysis-Differential Scanning Calorimetry (TGA-DSC) were used to determine the size and the first sintering temperature of BCZSm, respectively. The structures of cathode, electrolyte and anode were analyzed via X-ray Diffraction (XRD). A thin film fuel cell of LSFNb / BCZSm / NiO-BCZSm was assembled and reached the highest power densities of 109 mW•cm-2 and 182.6 mW•cm-2 at 700 °C and 800 °C, respectively.