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In this paper, a fast positioning platform (FPP) is proposed, able to meet simultaneously the requirements of large stroke and high frequency response, developed based on a PZT (piezoelectric actuator) and a quad-parallel flexible mechanism, for application in precision machining. The FPP is driven by a high-stiffness PZT and guided by a flexible hinge-based mechanism with a quad-parallel flexible hinge. The proposed quad-parallel flexible hinge mechanism can provide excellent planar motion capability with high stiffness and good guiding performance, thus guaranteeing outstanding dynamics characteristics. The mechanical model was established, the input and output characteristics of the FPP were analyzed, and the working range (output displacement and frequency) of the FPP was determined. Based on the mechanical model and the input and output characteristics of the FPP, the design method is described for of the proposed FPP, which is capable of achieving a large stroke while responding at a high frequency. The characteristics of the FPP were investigated using finite element analysis (FEA). Experiments were conducted to examine the performance of the FPP; the natural frequency of the FPP was 1315.6 Hz, while the maximum output displacement and the motion resolution of the FPP in a static state were 53.13 μm and 5 nm, respectively. Step response testing showed that under a step magnitude of 50 μm, the stabilization times for the falling and rising edges of the moving platform were 37 ms and 26 ms, respectively. The tracking errors were about ±1.96 μm and ±0.59 μm when the amplitude and frequency of the signal were 50 μm, 50 Hz and 10 μm, 200 Hz, respectively. The FPP showed excellent performance in terms of fast response and output displacement. The cutting test results indicated that compared with the uncontrolled condition, the values of surface roughness under controlled conditions decreased by 23.9% and 12.7% when the cutting depths were 5 μm and 10 μm, respectively. The developed FPP device has excellent precision machining performance.

The microbial community diversity in huangjiu (yellow rice wine) vinasse during spontaneous fermentation into Xiangzao was analyzed by high-throughput sequencing. It turned out that the bacterial and fungal diversity was abundant. During the whole fermentation process, Proteobacteria was the dominant bacterial phylum, whose relative abundance ranged from 71.26% to 75.27%. The relative abundance of Firmicutes was 16.09% in the initial stage of fermentation and showed a downward trend in the middle and late stages. The dominant bacterial genera were Aquabacterium and Brevundimonas. The relative abundance of Aquabacterium was 22.48% at the beginning of fermentation, increased to 24.94% at the middle, and decreased to 21.29% at the end. Bacillus and Lactobacillus were also found during fermentation. The dominant phylum of fungi was Ascomycota, and its relative abundance decreased from 63.46% at the beginning of fermentation to 51.68% at the end. The dominant genus of fungi was Pichia, and its relative abundance ranged from 6.58% to 13.79%. Additionally, the relative abundance of Tausonia and Mortierella was above 3%. To sum up, the microbial community diversity is abundant during the spontaneous fermentation of huangjiu vinasse, and the fermentation process has a significant impact on the relative abundance of microorganisms.

This paper focuses on the outcome-oriented OBE concept and the teacher information-based teaching model. Then, a regression model was constructed to study teachers’ ability to teach in information technology, and the correlation between variables was studied using regression equations and significance tests. The influencing factors of teachers’ informatization teaching ability enhancement were studied through the indicators of teacher factor, school factor, and policy training, and the strategies of teachers’ informatization teaching ability enhancement in higher education institutions were proposed. The study showed that the overall mean value of teachers’ factors among the influencing factors was 4.09, and the mean values of motivation and self-efficacy were greater than 4 points. The overall mean value of school factors was 3.9, the overall mean value of policy training was 3.55, and the mean values of training, policy, and competition were all greater than 3. This study provides some references and ideas for improving teachers’ information technology teaching abilities in higher education institutions.

This paper compares the characteristics and methods of informatization teaching in higher vocational education with traditional teaching modes, extracts the factors affecting the quality of higher vocational informatization teaching, and constructs a preliminary evaluation index system of higher vocational informatization teaching quality based on evaluation principles and evaluation strategies. At the same time, the qualitative evaluation was transformed into a quantitative evaluation based on the affiliation theory of fuzzy mathematics, the index weight set was established, and the fuzzy comprehensive evaluation model was designed comprehensively. In the evaluation results, the ratios of teachers’ factor, students’ factor, teaching content influence factor, and teaching effect on the quality of information technology education were 0.39, 0.33, 0.34, and 0.36.

This paper analyzes the personal career planning of teachers in higher education institutions, the influencing mechanisms, and the influencing factors. A systematic GMM model was constructed by combining differential GMM estimation and horizontal GMM estimation, and the systematic GMM estimation commonly used in dynamic panels was improved and applied using more effective instrumental variables and continuously updated objective functions. The results of the GMM analysis obtained through the selection of the influencing factors showed that the proportion of senior teachers’ willingness to personal career development and planning decreased by -0.04 and 0.02, respectively, and the proportion of negative development to total development willingness increased by +0.02 and +0.01, respectively, and the proportion of positive development to total development willingness increased by +0.03 and +0.01, respectively, and all of them were significant at the 1% level.

Excessive biofluid around wounds can cause infection and prevent healing. In this study, an anisotropic quaternized chitosan (QC)/sodium alginate (AL)-based aerogel wound dressing was prepared via a directional freeze-drying technique inspired by the channel structure used for water transport in trees. The aligned channels provided the dressing with self-pumping ability, allowing it to rapidly and completely remove biofluids and absorb biofluids up to 1292.5 % of its own weight. To enhance the strength of the dressing, a double cross-linked network was constructed based on the QC-AL electrostatic attraction and AL-Ca2+ chelation interaction. The axial compressive strength of the double cross-linked dressing reached 207.3 kPa (ε = 50 %). In addition, the dressing exhibited strong conductive properties (conductivity = 13.0 S/m), antioxidant activities [reactive oxygen species (ROS) scavenging ability = 88.0 %], and hemostatic characteristics (blood coagulation index = 1.8 %). The dressing also exhibited powerful antibacterial performance, exhibiting over 98.0 % inhibition of E. coli and S. aureus. Experiments on diabetic mouse models revealed that the dressing considerably promoted wound healing. On day 3, the wound healing rate was 96.7 % faster in the QAC group than in the gauze group. Therefore, the developed dressing may have great potential for chronic wound care.

The compositions of water extract (WE) and crude theabrownin (TB) extract from ripe Pu-erh tea prepared by controlled fermentation were analyzed by Curie point pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) and high performance liquid chromatography (HPLC) and their regulatory effects on obesity in rats were investigated. SD rats were divided into four groups, namely normal diet, high-fat diet, WE and TB. After gavage for 16 weeks, growth indexes, and serum biochemical indexes, oxidative stress and inflammation indexes were analyzed, and histopathological examination of liver tissues was performed by hematoxylin-eosin (HE) and oil red O staining. Results showed that theabrownin, protein and polysaccharide accounted for a large proportion in WE and crude TB. There were significant differences in the contents of catechin and its derivatives such as gallic acid (GA), epicatechin (EC) and epicatechin gallate (EGCG) between WE and crude TB extract (P < 0.05). The contents of the alkaloids caffeine and theobromine in WE were significantly higher than those in TB (P < 0.05). Seven and 12 compounds were shared by the Curie-point pyrolysis products of WE and TB at 380 and 600 ℃, respectively. In the four samples, the number of phenolic compounds was largest, and caffeine was the most abundant compound. Compared with the high-fat model group, the body mass and Lee’s index of the rats from the WE and TB groups significantly decreased (P < 0.05), and so did the levels of serum triglyceride (TG), serum fasting blood glucose (FBG), liver triglyceride and cholesterol (TC) ( P < 0.05), Moreover, fat accumulation was reduced, the levels of serum superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), nuclear factor E2 related factor 2 (Nrf2), interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) were lowered significantly (P < 0.05). These findings indicate increased antioxidant activity and decreased inflammatory factor levels. Furthermore, histological observations of liver sections showed reduction in steatosis, the number of adipocytes and lipid droplet aggregation. To sum up, the compositions of WE and TB were significantly different; however, both showed a positive effect on mass loss and blood lipid reduction. This study can provide a theoretical basis for the deep processing of tea resources and the development of functional products.

Copper(II) chloride anionic coordination complexes with different imidazole‐derived ligands due to the potential cytotoxic activity play the important role in protein. By investigating the experimental electron paramagnetic resonance (EPR) and ultraviolet–visible (UV–vis) spectra of [CuCl(C6H10N2)4]Cl, [CuCl(C6H10N2)4]Cl, [CuCl2(C4H6N2)4], and [Cu2Cl2(C5H8N2)6]Cl2·2H2O, the local structure of the corresponding Cu2+ centers and the role of different ligands are obtained. Based on the well‐agreed EPR parameters and the d‐d transitions (10Dq), the four Cu2+ centers show tetragonal and orthorhombic distortion, corresponding to the different anisotropies of EPR signals. In addition, the general rules of governing the impact of methanol in imidazolylalkyl derivatives are also discussed, especially the influence on the local environment (symmetry, distortion, covalency, and crystal field) of above four copper(II) chloride anionic coordination complexes. Therefore, the obtained results in this study will be beneficial to provide a theoretical basis for the experimental design of desired copper‐containing imidazolyl alkyl derivatives. [ABSTRACT FROM AUTHOR]