二语词汇习得石化消解的认知语言学研究

词汇习得过程分析表明母语介入是二语词汇习得石化的主要原因,用认知语言学理论指导二语词汇习得石化消解研究具有重要的理论和现实意义。典型理论、隐喻、转喻与意象图式结合起来可较好地解释多义词义项之间的理据及不同词汇之间的关系。认知语言学角度的二语词汇习得有助于学习者构建较为系统的词汇网络,习得语言事实背后的认知机制,加强二语词汇的语义与二语概念直接紧密的相通,理解和生成词汇,提高词汇能力,防止词汇习得中的石化现象。     

Corrosion-resistant analogue of Hadfield steel

The concept of alloying austenitic steels with carbon + nitrogen is used for the development of a corrosion-resistant austenitic CrMn steel having an impact wear resistance close to that of the Hadfield steel. A higher stabilization of the austenitic phase by C + N, as compared to carbon or nitrogen alone, is substantiated by ab initio calculation of the electron structure, measurements of the concentration of free electrons and calculations of the phase equilibrium. Based on these results, the compositions (mass%) Cr18Mn18C0.34N0.61 and Cr18Mn18C0.49N0.58 were melted and tested along with Hadfield steel Mn12C1.2. Mechanical tests have shown that, as compared to the Hadfield steel, the experimental steels possess a higher strength, plasticity, hardness and the same resistance to impact wear. TEM studies of the surface layer after impact treatment revealed a mixture of the amorphous phase, nanocrystals and fine-twinned austenite. At the same time, using Mössbauer spectroscopy of conversion electrons, the ferromagnetic ordering was found in the surface layer of up to 10 μm in depth, which is the sign of the strain-induced martensitic phase. The hypothesis of a transition from the low-spin to the high-spin state of the iron atoms within the thin twins in austenite was proposed in order to interpret the discrepancy between TEM and Mössbauer studies. Potentiodynamic measurements and immersion tests show that the CrMnCN steels possess a significantly higher pitting potential and resistance to general corrosion in comparison with Hadfield steel.     

Formation of CaO-TiO2-MgO-Al2O3 dual phase inclusion in Ti stabilized stainless steel

The formation of CaO-TiO2-MgO-Al2O3 dual phase inclusion in 321 stainless steel was investigated in the laboratory. The result indicated that the condition for the formation of CaO-TiO2-MgO-Al2O3 in 321 steel is [Ca]〉0.001wt%, [Ti]〉0.1wt%, and [A1]〉0.01wt%. The mechanism is the following： Al2O3 inclusion turns into CaO-Al2O3 after Ca-Si wire is fed into the molten steel; [Mg] is then obtained by reducing MgO in slag or crucible wall by [Al] and [Ti]; finally CaO-Al2O3 inclusion is changed into CaO-TiO2-MgO-Al2O3 by the reaction with [Mg], [Ti], and [O] in the molten steel simultaneously.     

华龙国际大厦混合结构构件及节点设计

论述了矩形钢管混凝土柱钢框架、混凝土核心筒结构在江西华龙国际大厦的应用，介绍了矩形钢管混凝土混合结构总体设计、节点大样及构造。     

合金钢中白点缺陷超声反射波辨析

通过对进口合金钢中白点缺陷超声反射波形的分析研究，为白点缺陷的判定提供借鉴，保证工程材料的使用安全。     

冷镦钢新型脱氧剂的试验研究

采用新型复合脱氧剂和脱氧工艺对冷镦钢进行工业性试验研究，研究结果表明：冷镦钢采用AlMg合金脱氧获得了良好的脱氧效果，可以避免形成大型夹杂物，提高钢水纯净度。     

时间分解光谱技术在钢铁分析中的应用

研究了单火花光谱在不同采样时间段分析灵敏度与窗口的关系,P、S、Al、Ni、Ti、B、Mg、Sb、Pb、As、Bi、Ta、Sn应用TRS技术检出限明显降低,而C、Si、Mn、Cr、Mo、V、W、Co、Nb则不显著;合适的采样窗口能提高Sb的分析准确度,Mg则可减少背景波动带来的影响,Cu可扩大分析线性范围;采用TRS技术在诸有效元素中分析灵敏度可提高1.36～5.00倍,能更好地满足品种钢的研究开发与生产检验的需求.