磁流体密封机理

1 Introduction Sealing with magnetic fluids is one of the most suc-cessful applications of magnetic fluids .This techniquewas first put forward in the 1970’s .It overcomes thedisadvantages in traditional sealing. Rotational leakage has al ways been a pro…     

中国古代共振效应应用续说

介绍了中国古代巧妙应用共振效应取水、扩音、准律、娱乐、预测、防振等 .从而充实了“中国古代共振研究与应用”一文的部分内容 .     

Rb~(87)基态超精细塞曼能级的磁共振

本文论述了光泵磁共振对Rb87基态超精细塞曼能级的研究．利用光抽运测量了Rb87基态塞曼能级磁共振波谱及其参数.     

随机共振系统数值仿真中的参数分析

用数值方法研究了随机共振(SR)系统.理论分析表明,正弦信号在系统输出中的数值表现仍为正弦信号,白噪声的效应是维纳过程,较小的系统参数才能使随机共振系统发生信号调制噪声效应.仿真实例验证了分析结果.     

乙二胺四乙酸桥联锰配合物的结构和磁行为

A trinuclear Mn(Ⅱ)coordination complex Mn_3(HEDTA)_2·10H_2O(EDTA=ethylene diamine tetraacetic acid)1 has been synthesized and characterized by X-ray crystal structure determination.In addition,IR spectrum,thermogravimetric analysis,electron paramagnetic resonance(EPR)spectra and magnetic susceptibility of this complex are discussed.X-ray determination indicates that six-and seven-coordinate modes between Mn(Ⅱ)and H_4EDTA exist alternately in 1.Furthermore, detailed discussion of magnetic ordering in the temperature range of 2～300 K reveals the antiferromagnetic interactions in the complex.     

先秦原创性教育思想研究

先秦时期是中国历史上的“轴心时代”,“轴心时代”创生了极为丰富的原创性教育思想,这些具有历久弥新生命力的原创性教育思想对于丰富中国教育理论,指导中国的教育改革与实践曾经发生并正在发生着十分重要的影响,分析其促生因素,挖掘其意义与价值有助于更好地借鉴历史的智慧,进一步推动我国的教育创新。     

民族民间唱法和美声唱法歌唱技术的比较

我国声乐界学院派教学的主要唱法流派体系是民族民间唱法和美声唱法，两者在歌唱呼吸技术，发声技术，共鸣技术以及咬字吐字上存在着差异，对此进行深入研究剖析对学习和探讨歌唱技术，推动我国声乐事业的发展，有着极大的现实意义。     

声速测量实验仪器和方法的改进

通过对声速测量的三种方法进行比较，得出肜共鸣管驻波法测量声速，学生最易操作，但实验中出现的二个问题，本将对其实验仪器和实验方法提出改进，加以修正，从而得到很好的实验效果。     

35 kV电压互感器损坏的原因分析及预防措施

针对中性点不接地电力系统，分析了35kV电压互感器损坏的原因。阐述了解决谐振过电压问题所采取的措施。     

柠檬酸含量对溶胶凝胶自燃烧法制备的钡铁氧体磁性能的影响

BaFe12O19 powders with nanocrystaUine sizes were produced by sol-gel auto-combustion method. The precursors were prepared under the molar ratios of citric acid to the metal nitrate of 0.5, 1.0 and 1.5. Appropriate ethylene diamine （C2H8N2） was added in order to adjust pH of 7. The ions distribution of citric acid at different pH explains the effect of citric acid in the starting solution. The XRD patterns of the as-burnt powders and annealing powders show different phases for different citric acid content. In addition, the lattice constants （a, c） derived from X-ray diffraction pattern were changed from 0.58881 nm to 0.58997 nm and 2.32057 nm to 2.32296 nm respectively. The data from VSM indicated that the powder with high citric acid content took on good magnetic properties. Pure single BaFe12O19 of the specific maximum magnetization M（1 T）≈ 49.73 Am^2/kg, the specific remanent magnetization Mr ≈ 30.77 Am^2/kg and the coercive force He≈ 467 kA/m was produced when the molar ratios of citric acid to the metal nitrate was 1.5.