High-pressure hydrogen tanks which are composed of an aluminum alloy liner and a carbon fiber wound layer are currently the most popular means to store hydrogen on vehicles. Nevertheless, the aluminum alloy is easily affected by high-pressure hydrogen, which leads to the appearance of hydrogen embrittlement (HE). Serious HE of hydrogen tank represents a huge dangers to the safety of vehicles and passengers. It is critical and timely to outline the mainstream approach and point out potential avenues for further investigation of HE. An analysis, including the mechanism (including hydrogen-enhanced local plasticity model, hydrogen-enhanced decohesion mechanism and hydrogen pressure theory), the detection (including slow strain rate test, linearly increasing stress test and so on) and methods for the prevention of HE on aluminum alloys of hydrogen vehicles (such as coating) are systematically presented in this work. Moreover, the entire experimental detection procedures for HE are expounded. Ultimately, the prevention measures are discussed in detail. It is believed that further prevention measures will rely on the integration of multiple prevention methods. Successfully solving this problem is of great significance to reduce the risk of failure of hydrogen storage tanks and improve the reliability of aluminum alloys for engineering applications in various industries including automotive and aerospace.

Traditional thickness-prediction methods underestimate the actual dome thickness at polar openings, leading to the inaccurate prediction of the load-bearing capacity of composite hydrogen storage vessels. A method of thickness prediction for the dome section of composite hydrogen storage vessels was proposed, which involved fiber slippage and tow redistribution. This method considered the blocking effect of the port on sliding fiber tows and introduced the thickness correlation to predict the dome thickness at polar openings. The arc length corresponding to the parallel circle radius was calculated, and then, the actual radius values corresponding to the bandwidth were obtained by the interpolation method. The predicted thickness values were compared with the actual measured thickness. The maximum relative error of the predicted thickness was 4.19%, and the mean absolute percentage error was 2.04%. The results show that the present method had a higher prediction accuracy. Eventually, this prediction method was used to perform progressive damage analysis on vessels. By comparing with the results of the cubic spline function method, the analysis results of the present method approached the actual case. This showed that the present method improved the accuracy of the design.

The chemical composition and particle size distribution as well as the physical-mechanical characteristics of fly ash of Krasnokamensk combined heat and power plant (CHPP) were determined. The revealed features provided the development of the technology of fly ash enrichment. The composite building material based on both fly ash of Krasnokamensk CHPP and technical sulfur was developed. Aluminum chloride was proposed to be used as modifier. The basic physical-mechanical properties of sulfur crushed stone were investigated.

Abstract:One catalytic discoloring spectrophotometry with double indicators and dual wavelength is proposed in the Thesis to measure the content of trace iron in three kinds of hematinic, artemisia integrifolia and other vegetables. In HCI medium, methyl orange and methylene blue are indicators. At wavelength of 500 nm and 665 nm, the change value ΔA in absorbance of catalytic system and non-catalytic system is measured and thus the iron content is measured. The conclusion is that the Method is characterized by simple operation, high sensitivity, favorable selectivity and reliable results.

High anisotropic Nd13Fe75Co4B8 magnetic powders are obtained with low desorption H2-pressure of the hydrogenation disproportionation desorption recombination (HDDR) process. Scanning electron microscopy (SEM) indicates a lamella structure in the 20 kPa desorption H2-pressure HDDR products and may be related to the high anisotropy. The magnetic powders with a desorption H2-pressure of 20 kPa have the magnetic properties of Br =0.86 T and Mr/Ms =0.81.This shows that the H2-pressure has great effect on the formation of crystal texture in the HDDR Nd-Fe-B powders.

Anisotropic Pr12.5Fe72.5Co6Cr2B7 magnetic powders are obtained by varying the desorption H2-pressure of the hydrogenation disproportionation desorption recombination (HDDR) process. The magnetic powders with a desorption H2-pressure of 30 kPa have the magnetic properties of Br =0.96 T, iHc=8.2 kOe and Br/Bs =0.78, whereas the magnetic powders obtained with a higher and a lower desorption H2-pressure are isotropic. A distinct lamella crystal is observed in the 30 kPa desorption H2-pressure products and may be related to the anisotropy in the HDDR-treated powders. It is believed that the desorption H2-pressure has great effect on the formation of crystal texture in the HDDR Pr-Fe-B powders.

Anisotropic Nd13.5Fe79.5B7 magnetic powders are obtained by varying the desorption H2-pressure of the hydrogenation disproportionation desorption recombination (HDDR) process. The magnetic powders with a desorption H2-pressure of 10 kPa have the magnetic properties of Br =0.61 T and Mr/Ms =0.67, whereas the magnetic powders obtained with a higher and a lower desorption H2-pressure are isotropic. A lamella crystal is observed in the 10 kPa desorption H2-pressure products and may be related to the anisotropy in the HDDR-treated powders. It suggests that the desorption H2-pressure has great effect on the formation of crystal texture in the HDDR Nd-Fe-B powders.