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The neutron reference radiation field of different components is the basic condition for the performance test of neutron shielding materials. In order to obtain an ideal neutron field for neutron protection material testing, a multi sphere energy spectrum measurement system based on 3He tube was constructed. The neutron radiation field slowing down condition based on 241Am-Be and 252Cf neutron sources was simulated and the energy spectrum was measured. In order to accurately judge the neutron scattering at the calibration reference position of the laboratory, the neutron scattering component measurement was carried out based on the multi sphere neutron spectrum measurement system. The dose rate conversion of the energy spectrum was carried out using the dose dose conversion coefficient recommended by ICRP. Compared with the results of the long counter, it was found that the deviation of the dose rate at the calibration position was not more than 20%. The experimental study on obtaining specific energy spectrum of polyethylene moderated isotope neutron source was carried out. The simulated calculation and experimental measurement of moderated spectrum were carried out, and the results were in good agreement. This work provides a useful neutron radiation field for the subsequent neutron metrology test and neutron protection material test.

In the field of agro-grassland, the synergism of phosphate (P) fertilization and Trichoderma inoculation in alfalfa production and the underlying mechanism of rare and abundant microbes that regulate rhizosphere soil processes in various environments are key but rarely studied topics. Here, we conducted field research through the inoculation/noninoculation of Trichoderma and five levels of phosphorus fertilizer to explore the biological relationships of rhizosphere soil properties, rare and abundant taxa, and alfalfa yields. Our results demonstrate that using Trichoderma inoculation and 15 g/m2 of phosphorus fertilizer exhibited optimal alfalfa yield compared with other treatments. alfalfa yields significantly (R2 = 0.33; p < 0.001) increased along with soil fertility. Both rare (RANOSIM = 0.900; p = 0.001) and abundant (RANOSIM = 0.769; p = 0.001) bacterial communities were significantly different under Trichoderma inoculation and P fertilization in a nonmetric multidimensional scaling (NMDS) analysis. Furthermore, different ecological processes dominated the rare and abundant bacterial community assembly. PLS-PM analysis showed that Trichoderma inoculation positively regulated the abundant bacteria community and P fertilization regimes manipulated the rare bacteria community, synergistically contributing to alfalfa yields. Overall, this article believes that inoculation with Trichoderma and appropriate application of phosphorus fertilizer can significantly increase alfalfa yield and affect soil enzyme activity, and the rhizosphere soil abundant and rare bacterial community characteristics have different responses to the synergistic effect of Trichoderma and phosphorus fertilizer. Our research emphasizes the fundamental role of abundant and rare microbes in maintaining crop production using Trichoderma inoculation and P fertilization. Therefore, distinguishing rare and abundant species is beneficial to comprehensively understanding microbial-driven processes and providing theoretical support for maintaining ecosystem productivity. [ABSTRACT FROM AUTHOR]

The present article is devoted to the application and recent research of underfloor heating. As underfloor heating is used all over the world, there is a great deal of various studies on the topic. In the current article different types of underfloor heating as well as modern scientific developments and research are presented. Also, regulatory documentation that normalizes the parameters of the system under consideration is described. The studies of A.O. Stimakov and Waldemar Scheller who invented panels for underfloor water heating system are described. The theoretical work of E.P. Bazunov and V.U.Kravchuk who conducted a study on underfloor heating using an economic method has been considered and, as a result, a comparison of two types of underfloor heating depending on the area of the premise was performed. The results of Yu Wanga, Zhigang Zhanga, Falong Hea and Xueli Liub who carried out an experimental study on the step of laying a warm floor using a special installation that enables us to reproduce the real parameters of the microclimate of the premise have been studied.

A comprehensive two-dimensional (2D) time-domain numerical model is established to investigate the interaction of irregular waves and submerged structures with different sections. The model specifically focuses on the dual-lane submerged floating tunnel (SFT) designs, encompassing elliptical, twin-circular, and round rectangular sections. For the hydrodynamic analysis, we adopt the second-order potential flow theory, while for the mooring line simulations, we employ the slender rod theory, taking into account the entire hydrodynamic load acting on it. In the coupled dynamic analysis, the fourth-order Adams–Bashforth–Moulton method, Newmark-β method, and Newton–Raphson iteration scheme are utilized for the coupled motion equation of the floating body and the dynamic equation of the mooring riser system. Experimental free decay tests are conducted to determine the damping coefficients of various section shapes in different directions. Our analysis delves into the detailed motion responses and mooring tensions of the SFTs with different section forms under irregular waves. We compare and contrast these responses in both time and frequency domains, particularly focusing on movement trends. The elliptical section structure emerges as the most stable design based on our comparisons. These findings provide valuable insights for the selection of optimal section shapes for dual-lane SFTs. [ABSTRACT FROM AUTHOR]

Existing bollard force measurement methods have not yet been able to realise simple, accurate, and efficient measurements of the bollard force of a single ship's cable. In this paper, an experimental study on the measurement of ship bollard force is carried out with reference to the calculation method of measuring the cable force of a diagonal cable. Based on the fundamental frequency method and the frequency difference method, a new comprehensive method is proposed to detect the fundamental frequency of cable vibration. A study on the identification of the cable condition based on the measured vibration data is also carried out. Experimental studies on the error rate of different data acquisition positions, excitation methods, excitation positions, wetted cables, different temperatures, and other influencing factors were conducted, and a new excitation method based on environmental excitation and artificial excitation was proposed. By analysing the calculated values of the vibration frequency method and the tensile values of the prototype test platform, it is concluded that the data acquisition position, excitation position, and excitation method have a small influence on the measured value of the ship's bollard force, and the range of the error rate increases by about 1.5% under the wetting of the cable and ±2% under the low temperature (2 °C), with the integrated error range of −5% to 4%, and the error rate can satisfy the normal distribution well, and the measurement accuracy is corrected by correcting the length of the cable. The measurement accuracy is corrected by correcting the cable length. It is proved that the method has strong feasibility and applicability, and can effectively realise simple, accurate, and efficient measurement of ship bollard force. [ABSTRACT FROM AUTHOR]