奥氏体不锈钢焊接热影响区开裂敏感性的测试与研究

应用热机械模拟系统Ｇｌｅｅｂｌｅ２０００Ｓｙｓｔｅｍ，通过焊接热影响区（ＨＡＺ）致脆开裂物理本质的模拟性试验———热拉力试验，对两种某核电站用高压热水管道材料———含铌和含钛奥氏体不锈钢的ＨＡＺ韧脆性变化行为进行了测试和研究．结果表明：ＨＡＺ致脆开裂敏感性随铌、钛含量的增加而提高，且含铌钢的ＺＤＲ（零韧性区域）远大于含钛钢．     

STUDY ON ELEVATED TEMPERA-TURE MECHANICAL PROPERTIES OF AM50HP WITH ND

Effects of Nd on the mechanical properties of die casting magnesium alloys AM50 are investigated. It is found that the ultimate tensile strength, yield strength and elongation of the AM50 alloy at elevated temperatures up to 200 ℃ increase with an addition of Nd. Generally, the most significant improvement in the tensile properties is attained at 100 ℃. The presence of Mgl2Nd is proved by X-ray diffraction. Microstructural observations reveal that the addition of Nd can lead to the dispersion-strengthening. Due to the presence of Mgl2Nd, the sliding of grain boundaries is restrained and the strength of the alloy is enhanced. It can be seen from the tensile fractographs that the fracture surfaces exhibit the mixed fracture characteristics, and less brittle fracture is observed with increasing the temperature. Quasi-cleavage fracture is thought as the main fracture mode. TEM observations expose the formation of dislocation network, slip lines and dislocation pile-ups.     

非接触式IC卡中的射频识别技术

介绍了射频识别技术在非接触式IC卡中的应用，对非接触式的IC卡的射频通讯的实现中的问题作了探讨。并对TypeA和Type B两种通讯编码标准的差异进行了比较。最后，在射频IC卡向CPU卡发展的方向作了一些展望。     

Photoluminescent properties of LiSrxBa1−xPO4:RE (RE = Sm, Eu) f-f transition phosphors

Rare-earth ions (Sm³⁺ or Eu³⁺) doped LiSr_xBa_1−xPO₄ (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) f-f transition phosphor powders were prepared by a high temperature solid-state reaction. The resulted phosphors were characterized by X-ray diffraction (XRD) and photoluminescence (PL) spectroscopy. The results of XRD indicate that the phase structure of the sample changes from LiBaPO₄ to LiSrPO₄ when x changes from 0 to 1.0. The excitation spectra indicate that only direct excitation of rare earth ions (Sm³⁺ or Eu³⁺) can be observed. The doped rare earth ions show their characteristic emission in LiSr_xBa_1−xPO₄, i.e., Eu³⁺⁵D₀-⁷F_J (J = 0, 1, 2, 3, 4), Sm³⁺⁴G_5/2 → ⁶H_J (J = 5/2, 7/2, 9/2, 11/2), respectively. The dependence of the emission intensities of the LiSr_xBa_1−xPO₄:Sm³⁺ and LiSr_xBa_1−xPO₄:Eu³⁺ phosphors on the x value and Ln³⁺ (Ln³⁺ = Sm³⁺, Eu³⁺) concentration is also investigated.     

Corrosion inhibition and adsorption behavior of 2-((dehydroabietylamine)methyl)-6-methoxyphenol on mild steel surface in seawater

The inhibition effect of a Dehydroabietylamine Schiff base derivative, namely 2-((dehydroabietylamine)methyl)-6-methoxyphenol (DMP) against mild steel corrosion in seawater was evaluated using weight loss and electrochemical techniques (potentiodynamic polarization and electrochemical impedance). The experimental results showed that DMP is a good corrosion inhibitor and the inhibition efficiency increased with the increase of DMP concentration, while the adsorption followed the Langmuir isotherm. X-ray photoelectron spectroscopy, scanning electron microscopy, theoretical calculation of electronic density, molecular electrostatic potential and molecular dynamics were carried out to establish mechanism of corrosion inhibition for mild steel with DMP in seawater medium. The inhibition action of the compound was assumed to occur via adsorption on the steel surface through the active centers in the molecule. The corrosion inhibition is due to the formation of a chemisorbed film on the steel surface.