A compact cladding-pumped Er:ZBLAN mid-infrared pulsed fiber laser using a liquefying gallium mirror as a saturable absorber is demonstrated for the first time. Preliminary results give pulse widths of 7 µs and energies of 38 nJ.

Railway wind-break wall is widely used, which is of significant importance to prevent running vehicles from suffering the risk of overturning. In the paper, application of railway wind-break wall and specific details of its structure are introduced. Wind tunnel test and CFD simulation are widely used in the researches on the performance of railway wind-break wall and some important results are summarized. Based on the review, developments of railway wind-break wall in the future are provided.

980MPa grade high strength low alloy steel was welded by ultra-narrow gap welding. Observed by optical metalloscope, there were large majority of equiaxial crystals in weld centers, which was the weld cross-section of 18.3%. Each weld could be compartmentalized into original microstructure zone, over heated zone and normalizing zone under next weld thermal cycle, in which the microstructures were almost the same. Through quantificational metallographic analysis, it was found there was more than 98.9% of acicular ferrite in weld metal, and other microstructures were fine. Mechanical test indicated that the strength of weld metal was higher than body material, and had outstanding plasticity. What is more, the toughness of weld metal was better than solder wire.