The effects of mechanical strength and yield ratio on the seismic steel are significant. This paper investigated the mechanical strength and yield ratio of medium carbon seismic steel by deep cryogenic treatment at −60°C and −110°C for 60∼120 s and tempering at 350°C for 30 minutes. The microstructure, misorientation, grain boundary, and size were characterized by electron backscattering diffraction (EBSD), scanning electron microscopy (SEM), and energy dispersive spectrometery (EDS). The result shows that the tensile strength and reduction of the cross-sectional area of steel were increased by 170 MPa and 9% and yield ratio and elongation were decreased by 0.13 and 9% due to the existence of the large-angle grain boundary. The present study confirms that the mechanical properties of medium seismic steel can be improved effectively by the deep cryogenic treatment and tempering.

The QRS complex detection is very important to ECG analysis. This paper aims to present an algorithm of QRS complex detection based on mathematical morphology and envelope. Baseline wandering is removed from ECG signal by morphological method. Then the signal gets the envelope through a low-pass filter, improving signal-to-noise .The performance of the algorithm is evaluated with MIT-BIH database. The algorithm gets the high detection rate (99.79%) and high speed.

Deep cryogenic treatment (DCT) in the phase transition region of austenite (A) to ferrite (F) is a novel process that can efficiently improve the content of martensite (M) and F of dual phase (DP) steel. In this work, microstructure transformation in DP structural steel treated by DCT was investigated in detail. Scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) were used to characterize the microstructure, alloy distribution, grain size, and orientation for the DP structural steel. The results demonstrated that DCT could effectively improve the yield ratio and mechanical properties of the tested steel. F and its large-angle significantly reduced the influence of fine-grain strengthening on the reduction of yield ratio. This research offered innovative technical support and theory guidelines for producing and studying such extraordinary strength-toughness DP steel with high strength and low yield ratio.

A new kind of composite with a bi-continuous structure was produced by pressure infiltrating melt Zr41.2Ti13.8Cu12.5Ni10Be22.5 into porous SiC which was made by powder metallurgy. Microstructure investigations of the composite show that the melt alloy was fully infiltrated into the voids of porous SiC and quenched into amorphous state. Both the amorphous alloy and the porous SiC exhibit a three-dimensional interconnected net structure. The study of thermal properties reveals that the addition of porous SiC reduces the width of supercooled liquid region of the composite. The bicontinuous composite presents 2% plastic strain and ultimate strength of 1250MPa.

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