这低音真帅——曼琴M2SW.1044

衡量一个器材好与坏,我觉得要考虑三个方面：首先是＂听＂,声音好、效果强,这是一台音响器材必须做到的;其次是＂看＂,样子美观漂亮的器材,看起来顺眼、拿出来显摆更倍有脸子;最后是＂用＂,便于安装、坚久耐用,无形中等于提高了一台器材的实际价值。     

Preparation of ferromagnetic binary alloy fine fibers by organic gel-thermal reduction process

Ferromagnetic metal fibers with a high aspect ratio （length/diameter） are attractive for use as high performance electromagnetic interference shielding materials. Ferromagnetic binary alloy fine fibers of iron-nickel, iron-cobalt and cobalt-nickel were prepared by the organic gel-thermal reduction process from the raw materials of critic acid and metal salts. These alloy fibers synthesized were featured with a diameter of about 1 pm and a length as long as 1 m. The structure, thermal decomposition process and morphologies of the gel precursors and fibers derived from thermal reduction of the gel precursors were characterized by FTIR, XRD, TG/DSC and SEM. The gel spinnability largely depends on the molecular structure of metal- carboxylates formed during the gel formation. The gel consisting of linear-type structural molecules shows good spinnability.     

穆斯堡尔谱在钙铁硅铁磁体微晶玻璃研究中的应用

应用穆斯堡尔谱来研究钙铁硅铁磁体微晶玻璃中氧化铁的适宜允许含量、熔制条件、热处理气氛和晶化过程。结果表明,穆斯堡尔谱对于准确地研究钙铁硅微晶玻璃形成、热处理过程中铁离子的价态、配位、结构情况具有重要价值,与XRD等其它方法的研究结果相比可以得到更多的信息。     

Barkhausen效应在曲轴残余应力测试中应用的研究

本文从微观与宏观上分析了铁磁材料产生Barkhausen效应的机理,阐述了外磁场和应力对Barkhausen信号的影响,以及利用新研制的应力测试仪器对曲轴的残余应力进行的测试,论证了Barkhausen效应应用于曲轴残余应力测试中的可行性。     

磁记忆技术若干问题的讨论

从铁磁性材料的基本特性出发,探讨了用磁致伸缩方程组描述磁记忆的方法,给出了磁记忆磁场的数学表示式,讨论了磁记忆现象的基本规律和特点,分析了应力和偏磁场对材料磁特性的不同作用,提出了产生磁记忆的三个基本条件,即材料的压磁性、磁滞性和交变应力的反复作用,并对地磁场的作用给出了明确的解释。同时,分析了磁记忆研究存在的问题及其应用时的局限性等。     

COPNA树脂的合成及应用研究进展

COPNA树脂是一类新型高分子合成热固性树脂,它由多核芳香化合物。如萘、芘,在交联剂和酸性催化剂的作用下进行阳离子聚合反应得到。B阶COPNA树脂为线性结构,具有良好的可溶可熔性。交联后的C阶COPNA树脂性能优异,起始降解温度高达500℃。COPNA树脂还可用作C／C复合材料前躯体、有机铁磁体等。文中从合成方法、合成机理及应用领域对近些年来国内外COPNA的研究工作状况进行了简单的阐述。     

Effects of Sm on Phase Transformation in Ni-Mn-Ga Alloys

The effects of small amount additions of Sm on the martensitic transition and magnetic phase transition of polycrystalline Ni-Mn-Ga alloys were investigated. The experimental results show that the Sm doped alloys also undergo a thermal-elastic martensitic transformation and reverse transformation during cooling and heating process and the addition of Sm decreases the martensitic transformation temperature and Curie temperature in different degree respectively. Ni-Mn-Ga alloys of adding Sm still possess Heusler structure, but their crystal lattice parameters are modified slightly. The addition of a proper amount of Sm does not basically decrease Tc of the alloy when avoiding the appearance of second phase. In addition, the doped alloys have favorable toughness because of grain refinement of Sm.