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At present, most of the turbofan engine use the articulated link mount to connect the engine to the wing. The mechanical modeling, analysis and experimental research of articulated link mount are important means in the development of engine mount. In this paper, multibody dynamics method is used to establish the dynamic theory equation for a certain type of turbofan engine mount, and the low-frequency approximation method of the MNF file is proposed, which greatly improves the calculation speed on the basis of ensuring the calculation accuracy. In addition, a full-scale engine mounting system vibration isolation performance test platform was developed, and the vibration isolation efficiency of a certain type of engine mount at the high and low pressure rotor frequency was obtained. The results show that the simulation and test results agree well, the error is within 15% at the low-frequency, and 5% at the high-frequency. This work provides theoretical method and test evaluation means for the design and improvement of large passenger aircraft engine installation devices.

With the acceleration of propeller engine installation system's localization，the relevant technical research of installation system must be carried out，in which the dynamics design is one of the important parts. The dynamic performance characteristics of installation systems with different structures are firstly compared and analyzed. The technical requirements of the installation system dynamics design are summarized proceeding from the military and civilian standards and engineering practice experience. The development history and current situation at home and abroad of the installation system dynamics design techniques are reviewed. It is pointed out that the gap between home and abroad is mainly reflected in the design concept，key technology and practical experience of application. On this basis，the development trend of the dynamics design techniques of the propeller engine installation system is prospected in this paper and the reference for current and future research on the design techniques of propeller engine installation system is provided.

In recent years, with the continuous development of the tourism industry, changing the education model has become a fundamental problem that must be solved to cultivate the quality of professional talents, and the OBE education model has become the trend of higher education development. In this paper, the program design of tourism management mode based on OBE education is carried out in two aspects of personality characteristics cognition and personality learning resources, then constructs the learner characteristics model from several aspects of style similarity, behavioral similarity, learner influence relationship, and proposes the personality recommendation method based on deep learning after the selected experimental objects are experimental class and control class respectively, and through the analysis of the cognitive level of the students, learning style, interaction behavior characteristics were analyzed to verify the validity of the learning characteristic model and program design constructed in this paper. After the experiment, the average post-test score of the experimental group was 84.91, which is higher than the average post-test score of the C1 group, which is 83.63, indicating that the OBE education model based on the deep learning recommendation can improve the student’s learning performance.

In this paper, inspired from the technique of patch–aperture–patch, a novel tri-band frequency selective surface with second-order band-pass response in each operation band is presented. The design is implemented by cascading a two-dimensional periodic array of three square loops and an array of wire grids. The proposed structure composed of three metal and two dielectric layers acts as a spatial dual band microwave filter with large band separation. The predicted FSS has the merits of broadband response, excellent stability for different incident angles, and sharp roll-off at X-, Ku- and K-band, respectively. The simulation and measurement are carried out and discussed. The measured results agree well with the simulated ones.

To explore the effect of vermicompost on the yield and quality of tomato cultivated in salty soil, we investigated the soil chemical properties, the yield, vitamin C, organic acid, soluble solids, and nitrate of fruit, photosynthesis, and carbohydrates of plants grown under various salt levels applied with the application of either commercial chemical fertilizers, cow manure, or vermicompost. Results showed that the tomato yield was not increased from the chemical fertilizer application, while there was an increase from the cow manure and vermicompost (increased 31.7% and 65.2%, respectively) under salt stress. Compared to no salt stress, the contents of vitamin C, organic acid, soluble solids, and nitrate increased 26.55%, 40.59%, 46.31%, and 35.08%, respectively, under salt stress (2 g NaCl·kg−1 soil). Compared with the Control, the application of chemical fertilizers failed to improve the sugar/acid ratio but increased nitrate content, while cow manure and vermicompost improved the sugar/acid ratio by 42.0% and 73.1%, respectively. Particularly, vermicompost increased vitamin C and reduced nitrate to the greatest extent among the different fertilizer treatments. The decrease in sodium (Na+) in the roots and leaves, increase in carbohydrates in fruit, and photosynthetic efficiency of leaves imply an amendment effect of vermicompost on salt stress. Moreover, vermicompost also facilitated the transit of carbohydrates from leaves to fruits by increasing the accumulation of nitrogen, phosphate, and potassium in fruits, leaves, and roots, while decreasing proline and soluble protein accumulation in leaves and roots. In conclusion, vermicompost could alleviate the adverse effect of salt stress and improve tomato yield and fruit quality by improving the photosynthetic capacity and promoting carbohydrate transport to fruit. The findings give a new perspective on the beneficial effect of vermicompost on tomato yield and quality. [ABSTRACT FROM AUTHOR]