Weibin Li

This book introduces the fundamental theory of electromagnetic ultrasonic guided waves, together with its applications. It includes the dispersion characteristics and matching theory of guided waves; the mechanism of production and theoretical model of electromagnetic ultrasonic guided waves; the effect mechanism between guided waves and defects; the simulation method for the entire process of electromagnetic ultrasonic guided wave propagation; electromagnetic ultrasonic thickness measurement; pipeline axial guided wave defect detection; and electromagnetic ultrasonic guided wave detection of gas pipeline cracks. This theory and findings on applications draw on the author’s intensive research over the past eight years. The book can be used for nondestructive testing technology and as an engineering reference work. The specific implementation of the electromagnetic ultrasonic guided wave system presented here will also be of value for other nondestructive test developers.

This book introduces the fundamental theory of electromagnetic ultrasonic guided waves, together with its applications. It includes the dispersion characteristics and matching theory of guided waves; the mechanism of production and theoretical model of electromagnetic ultrasonic guided waves; the effect mechanism between guided waves and defects; the simulation method for the entire process of electromagnetic ultrasonic guided wave propagation; electromagnetic ultrasonic thickness measurement; pipeline axial guided wave defect detection; and electromagnetic ultrasonic guided wave detection of gas pipeline cracks. This theory and findings on applications draw on the author’s intensive research over the past eight years. The book can be used for nondestructive testing technology and as an engineering reference work. The specific implementation of the electromagnetic ultrasonic guided wave system presented here will also be of value for other nondestructive test developers.

Focusing on the theory and state-of-the-art technologies of ultrasonic testing (UT), this book examines ultrasonic propagation in solids and its detection applications, and explores the intersection of UT technology with various fields of electromagnetics, optics and physics.UT is one of the most widely used nondestructive testing techniques due to its high performance in terms of detection efficiency and safety. The rapid development of modern industrial products and technologies has created a new challenge and demand for ultrasonic nondestructive testing technology. This book introduces the fundamentals of UT, including sound wave and sound field, interface wave theory and liquid-solid coupled sound field. It then discusses various types of UT methods, ranging from the critically refracted longitudinal wave method to ultrasonic surface wave and ultrasonic guided wave detection methods. Some newly developed UT techniques are also discussed, including phased-array UT, high-frequency UT and non-contact UT.This title will appeal to engineering students and technicians in the field of ultrasonic nondestructive testing.

Analyses the reasons for the formation of the development strategy of China's metropolitan area and puts forward a set of theoretical framework for studying the development of the metropolitan area. This framework is used to further analyse the nine major metropolitan areas in China and summarise the experience and problems in the development of metropolitan areas in China. The author also puts forward the idea of developing the metropolitan area in the future.This book provides an in-depth analysis of the characteristics of the core cities, the extent to which the core cities are linked to the peripheral cities, the development capacity of the peripheral cities, the stage of the metropolitan area, the achievements and problems of the development of the metropolitan area, and the ideas for future development.