Improvement of coercivity thermal stability of sintered 2:17 SmCo permanent magnet by Nd doping

The effects of Nd doping on the microstructures and magnetic properties of Sm_(1-x)Nd_(x)(Co_(0.695)Fe_(0.2)Cu_(0.08)Zr_(0.025))7.2(x = 0, 0.3, 0.5, 0.7, 1.0) permanent magnets are studied. The scanning electron microscope(SEM) analysis of the solid solution states of the magnets shows that with the increase of Nd content, the distribution of elements becomes inhomogeneous and miscellaneous phase will be generated. Positive temperature coefficient of coercivity(β) appears in each of the samples with x = 0.3, 0.5, and 0.7. The corresponding positive β temperatures are in ranges of about 70 K–170 K,60 K–260 K, 182 K–490 K for the samples with x = 0.3, 0.5, and 0.7, respectively. Thermomagnetic analysis shows that spin-reorientation-transition(SRT) of the cell boundary phase is responsible for this phenomenon. On the basis of this discovery, the Sm_(0.7)Nd_(0.3)(Co_(0.695)Fe_(0.2)Cu_(0.08)Zr_(0.025))7.2magnet possessing thermal stability with β ≈-0.002 %/K at the temperature in a range of 150 K–200 K is obtained.

Laparoscopic combined with thoracoscopic transdiaphragmatic hepatectomy for hepatitis B-related hepatocellular carcinoma located in segment VII or VIII

Laparoscopic hepatectomy(LH)is considered a safe and effective method of treating liver cancer because of its relatively low level of trauma,bleeding,pain,and short hospital stay as compared with traditional open surgery[1].However,this is not ideal for tumors located in segment VII or VIII of the liver as these tumors are difficult to be exposed during laparoscopy,and the conversion rate is relatively high[2].Although it has been reported that the thoracoscopic transdiaphragmatic segment VII or VIII hepatectomy can obtain better visual field and operation space[3]。