No abstract

No abstract

No abstract

No abstract

No abstract

Electromagnetic acoustic transducers (EMATs) are non-contact, ultrasonic transducers that are usually kept within 5 mm from the sample surface to obtain a sufficient signal-to-noise ratio (SNR). One important issue associated with operation on a ferromagnetic plate is that the strong attraction force from the magnet can affect measurements and make scanning difficult. This paper investigates a method to generate fundamental, symmetric Lamb waves on a ferromagnetic plate. A coil-only, low-weight, generation EMAT is designed and investigated, operating at lift-offs of over 5 mm. Another design of an EMAT is investigated using a rectangular magnet with a much higher lift-off than the coil, of up to 19 mm. This results in a much lower force between the EMAT and sample, making scanning the EMAT much easier.

No abstract

This article firstly introduced the characteristics of the iron and steel industry of China during 2017. Then the production, raw material and operation indexes of large blast furnace of China were introduced. In addition, the manufacturing and procurement costs, energy consumption, labour productivity and national industrial policies were specifically analysed. The conclusion that the operation indexes of large blast furnace of China has development during 2017 was obtained. The study could benefit to understand the large blast furnace operation of China.