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Abstract A single type of signal processing means that it is difficult to analyze vibration signals comprehensively and effectively. By comprehensively using wavelet analysis techniques, a comprehensive and in-depth study of aero-engine vibration conditions is realized as a way to carry out health management. By introducing various types of wavelet analysis techniques and using Labview2022 programming, corresponding signal processing tools are developed for the analysis of the collected vibration signals. The comprehensive analysis of aero-engine vibration signals based on the wavelet transform method is realized, and the corresponding products are successfully applied in engineering practice.

In the era of the digital economy, live-streaming of agricultural products has become a new means of rural revitalization, which not only promotes the transformation of the rural economy but also deepens the dual promotion of villagers' rights and identities. Based on the practice of rural women's participation in the live-streaming of agricultural products, this study discussed the extent to which the live-streaming economy reconstructed rural women's identities and reproduced their production and living spaces from the perspective of feminist geography. Based on a sampling of villages representative of Qianpai Town, Guangdong Province, this study unfolded the opportunities, processes, and effects of women's empowerment in rural spatial transformation through qualitative research methods, such as participatory observation, in-depth interviews, and discourse analysis. Findings of the present study included: (1) while the live-streaming economy was found in the rural area, not only were diversified resources, such as policy, education, material, and cultural support, brought to Qianpai Town, but also rural women who either originally worked in cities or engaged in agricultural production obtained their new empowerment power. (2) The empowerment of rural women was prominently manifested in the reconstruction process of women's identity during the practice of digital entrepreneurship. Owing to the development of the digital economy, rural women self-reconstructed their identity from "migrant workers" to "returning entrepreneurs" and from "knowledge receivers" to "culture communicators", showing that they could expand their way of livelihood by mastering the right of independent employment, as well as the expansion of women's social network and the prominence of their dominant position. (3) The rural reconstruction under the live-streaming economy was a complex and dynamic process in which rural production and living spaces, private spaces, and public spaces were intertwined. The "familiarization" of live-streaming places broke the boundary between women's production and living spaces and facilitated the economic transformation of home space and the socialization of private space, thus contributing to the reconstruction of production and living spaces in rural areas. Overall, the practice of women's digital entrepreneurship contributed to the enhancement of their sense of self-value and the reshaping of their roles at home and in society to raise their voice and status in the economic activities of the family. This study argued that the coupling of rural women and the "live-streaming economy" in the digitalization process of rural areas provides a new research ground for deepening the understanding of women's empowerment mechanism through digital technology and the evolving human-place relationship of rural China. The analysis presented contributes to the exploration of the rural transformation and development processes from the perspective of the interaction between "women" and "place" and provides actionable insights into rural restructuring. The results of this study help to better understand the effects and mechanisms of the live-streaming economy on rural women as well as on their production and living spaces, thereby presenting theoretical and practical insights into rural women's empowerment through digital technology.

After many years of development, the technology of analyzing the working condition of power units based on vibration signals has received relatively stable applications, but the accuracy and the degree of automation and intelligence for fault diagnosis are still inadequate due to the limitations in the ongoing development of key technologies. With the development of big data and artificial intelligence technology, the involvement of new technologies will be an important boost to the development of this field. In this study, in order to support subsequent research, bibliometrics is used as a tool to sort the development of the technology in this field at the macro level. At the micro level, key publications in the literature are studied to better understand the development status at the technical level and prepare for the selection of entry points to facilitate in-depth innovation in the future.

Bi5O7I doped with Zn2+ (Zn2+/Bi5O7I) was prepared using a precipitation calcination method. Its photocatalytic activity was improved by adjusting the band gap of Bi5O7I, and its photocatalytic performance was evaluated by degrading RhB. The experimental results showed that Zn2+/Bi5O7I-8 had the highest photodegradation efficiency, and the degradation rate for RhB after exposure to light for 30 minutes was 91% and reached 100% in 60 minutes. The degradation rate constant k of Zn2+/Bi5O7I-8 reached 0.10813 min−1, which is 13 times more than that of Bi5O7I. As a result of Zn2+ being added into Bi5O7I, the band gap of Zn2+/Bi5O7I became narrower than that of Bi5O7I, and the photogenerated electrons and holes were successfully prevented from recombining; therefore, the photocatalytic activity of Zn2+/Bi5O7I was higher than that of Bi5O7I. After four rounds of photocatalytic experiments, the photocatalytic efficiency of Zn2+/Bi5O7I-8 remained high. The composition and microstructure of the materials were characterized using XRD, FTIR, XPS, SEM, and TEM. The optical properties and degradation mechanism of the material were investigated using DRS, PL, photocurrent response, and active substance capture experiments. A suggested mechanism for the photocatalytic degradation of RhB is presented. [ABSTRACT FROM AUTHOR]

Streptococcus agalactiae infection has become a serious bacterial disease of tilapia for its damage. In order to effectively prevent the outbreak of streptococcicosis, a recombinant Lactococcus lactis expressing surface immunogenicity protein (Sip) of S. agalactiae was constructed as probiotic vector oral vaccine in this study. The immunogenicity of the recombinant L. lactis was evaluated through detecting the level of specific serum IgM antibody, expression level of immune-related genes and relative percent survival (RPS). The results showed that the recombinant L. lactis could express a 45.5 kDa protein consistent with the expected size of Sip. The recombinant Sip mainly expressed in the form of inclusion body and the concentration of purified Sip could reach 7.65 mg / mL. Nile tilapia were orally immunized with different concentrations (2.24 × 109, 2.24 × 1010 and 2.24 × 1011 CFU / mL) of recombinant L. lactis (NZ9000-pNZ8148-sip). The analysis results of specific serum antibody showed that the level of antibody of tilapia which were vaccinated with medium and high concentration of recombinant L. lactis (2.24 × 1010 CFU / mL and 2.24 × 1011 CFU / mL) were significantly higher than that of control group. The relative percentage of survival (RPS) of tilapia vaccinated with medium concentration of NZ9000-pNZ8148-sip reached 61.6 % at 21 days post-immunization. Quantitative real-time PCR (qRT-PCR) results revealed that the immune-related genes of IgT, IgM, CD8a and C3 were significantly upregulated expression in thymus, liver, spleen and hindgut. In conclusion, the recombinant L. lactis vaccine induced both humoral and cellular responses of tilapia. This study demonstrates the potential of using L. lactis as a delivery system to develop an oral vaccine against S. agalactiae.

(001)-TiO2/BiOI photocatalysts with microsphere morphology were synthesized by a solvothermal method. The (001)-TiO2/BiOI demonstrated highest photocatalytic performance for the RhB degradation rate of 0.049 min−1 under visible light, which is 5 and 7 times that of (001)-TiO2 and BiOI, respectively. The increased photocatalytic efficiency is due to the construction of heterojunctions, which promote the transportation of photo-generated carriers. The good photochemical stability of the prepared photocatalysts was demonstrated by cycling experiments. The radical quenching experiments show that ˙O2− and ˙OH are the principal active species in the photocatalytic reaction mechanism. Finally, a possible mechanism of p–n heterojunctions in the photocatalytic reaction process was proposed. [ABSTRACT FROM AUTHOR]

This paper examines onwards migration patterns and the factors that influence them in urban China. In contradiction to Ravenstein's laws of step migration, we argue that movement up the urban hierarchy does not dominate onwards migration in the Chinese context. Using the 2017 China Migrants Dynamic Survey, we model how past migratory experiences intersect with migrants' demographic and socio-economic characteristics to explain the stay-versus-move decision and who moves up as well as who moves down within China's urban hierarchy. The general pattern of China's domestic migration is a movement up the urban hierarchy in the first migration and a movement down in onwards migration. We identify a transition-levels effect whereby the larger the difference between the hukou -registered place and the first migration city in the urban hierarchy, the greater the probability of onwards migration, with the effect manifesting most strongly for less-educated, mid-age (the 1970s and 1980s birth cohorts) migrants with rural origins. As to onwards migration direction, mixed results were found for migrants' demographic and socio-economic characteristics whereas educational level and the transition-levels effect are both highly predictive of movement up and down the urban hierarchy. Our findings suggest that 'jumping too high' in previous migration(s) predicts a greater likelihood of moving down the urban hierarchy in response to insurmountable obstacles to settling in cities classified as large and above. Our research advances migration scholarship by considering the multipolar nature of onwards migration and offering an integrated approach to analysis that foregrounds the causes and effects of multiple-step migration. [ABSTRACT FROM AUTHOR]

In this work, g-C3N4/ZIF-8 heterojunction photocatalysts were synthesised by the process by which the metal-organic framework ZIF-8 nanoparticles were grown onto the g-C3N4 layer in situ. Bismuth element was doped into the as-prepared g-C3N4/ZIF-8 material and a new type of Bi@g-C3N4/ZIF-8 composite photocatalysts was manufactured, in which the doping element acts in adjusting the bandgap in the photocatalysts. The prepared photocatalysts were characterised by XRD, FESEM, TEM, FTIR, XPS, UV–VIS DRS, photoluminescence and photo-electrochemical experiments. The results show that the ZIF-8 nanoparticles grown in situ were well-formed onto the g-C3N4 layer, and bismuth was evenly doped into the gaps of the g-C3N4/ZIF-8 framework. The degradation rate of methylene blue by CNZ-1.5(Bi)-12, which was a photocatalyst composed of 12% Bi-doped with g-C3N4/ZIF-8 material (the mass ratio of g-C3N4: ZIF-8 = 1:1.5), reached 86.6% under visible light irradiation within 60 min. The free radical scavenging experiment and electron spin resonance spectroscopy showed that ∙ OH was the main active substance. Bismuth doping into the photocatalytic system promotes the excitation of electrons from the valence band to the conduction band and provides a good channel for the transmission of photogenerated carriers as well. It is achieved that intensive visible light absorption, the enhanced separation efficiency of photogenerated carriers, and excellent thermal stability and high recyclability in the novel composite photocatalyst, owing to the synergistic effect of the introduced bismuth with the heterostructure of g-C3N4/ZIF-8. Therefore, the synthesised Bi@g-C3N4/ZIF-8 heterojunction photocatalysts may be used as a good photocatalyst for purifying and degrading organic matter in sewage. [ABSTRACT FROM AUTHOR]

A Z-scheme heterojunction was constructed by loading (001)-faceted TiO2 onto Bi5O7I through a simple deposition method. Characterization of the obtained photocatalysts included SEM, TEM, XRD, FT-IR, XPS, UV–vis DRS, and PL. The results showed that (001)-TiO2 nanosheets had been successfully anchored to the Bi5O7I nanobelts and the heterojunctions had been formed between them. The catalytic ability of the samples was assessed by degradation of Rhodamine B (RhB). The sample TB-20 exhibited the greatest apparent rate (0.04315 min−1), which was about 3 times that of pure Bi5O7I. The enhanced photocatalytic activity can be attributed to the visible response and charge division of the (001)-TiO2/Bi5O7I composite. The recyclability of the catalyst also showed good stability after four cycles with 90% degradation efficiency. Moreover, the degradation of RhB follows pseudo-first-order kinetics by non-linear least squares fitting to the degradation data. A plausible photocatalytic reaction mechanism has also been presented. [ABSTRACT FROM AUTHOR]