类氢类氦类锂镁离子双电子复合的旁观电子角动量研究

类氢类氦类锂镁离子经中间双激发态进行的双电子复合过程在研究惯性约束聚变电子温度中占有很重要的地位.用准相对论方法计算了双电子复合经不同Rydberg态跃迁通道的复合速率系数,并给出不同离化度离子的双电子复合速率系数随电子温度的变化规律.显示出离子的相关能对峰值的电子温度有很大影响,当类氢离子跃迁通道的旁观电子角动量为1时双电子复合系数最大,而类锂离子是旁观电子角动量为3时最大. 关键词： 双电子复合 镁离子 角动量     

Mossbauer investigations of corrosion environment influence on Fe valence states in oxide films of zirconium alloys

Mössbauer investigations about iron atom redistribution in oxide films of zirconium alloys subjected to corrosion at 500°C in pure oxygen and water pair have been analysed. The alloys were also subjected to autoclave conditions at a pressure of 10.0 MPa and autoclave conditions at 350°C and at a pressure of 16.8 MPa, using distilled water and water with additives of lithium and fluorine. It is shown that, depending on the corrosion environment, various compounds of iron, such as α-Fe₂O₃, Fe₃O₄, and FeO, as solid solutions of iron in ZrO₂ are formed in oxide films.     

侵彻环境下两种钨合金的细观响应特性

本文实验发现具有较大密度和较高速度的93W钨合金长杆模拟弹的穿靶深度反而比密度较小，速度较低的90W钨合金长杆弹的穿靶深度小．针对这一现象，本文从两种材料在侵彻环境下的细观响应特性的差异上给出了有实验根据的合理分析，结论是90W在侵彻环境下较易于形成绝热剪切带，从而在弹头部发生“自锐化”效应所致．     

ICP-AES同时测定混合矿物素中的磷、钙、铁、铜、锌、锰、镁、钴

采用ICP－AES法测定混合矿物素中的磷、钙、铁、铜、锌、锰、镁、钴元素含量，并对样品的溶解酸和酸用量、元素分析线的选择以及共存元素间的干扰进行了研究。该法简便、快速，精密度和准确度较好。     

Specific heat and related thermophysical properties of liquid Fe-Cu-Mo alloy

The specific heat and related thermophysical properties of liquid Fe77.5Cu13Mo9.5 monotectic alloy were investigated by an electromagnetic levitation drop calorimeter over a wide temperature range from 1482 to 1818 K. A maximum undercooling of 221 K (0.13 Tm) was achieved and the specific heat was determined as 44.71 J·mol-1·K-1. The excess specific heat, enthalpy change, entropy change and Gibbs free energy difference of this alloy were calculated on the basis of experimental results. It was found that the calculated results by traditional estimating methods can only describe the solidification process under low undercooling conditions. Only the experimental results can reflect the reality under high undercooling conditions. Meanwhile, the thermal diffusivity, thermal conductivity, and sound speed were derived from the present experimental results. Furthermore, the solidified microstructural morphology was examined, which consists of (Fe) and (Cu) phases. The calculated interface energy was applied to exploring the correlation between competitive nucleation and solidification microstructure within monotectic alloy.     

室温下压致铁钴镍合金的bcc→hcp相变

 本文采用高压X光衍射方法在金刚石对顶压砧中在位地（in situ）研究了Fe₆₈Co₂₄Ni₈（wt%）合金在室温下的压致bcc→hcp结构相变和直到40.5 GPa的等温压缩行为。实验结果表明该合金在常压下为bcc结构，晶格常数a₀=(0.287 0±0.000 1) nm，体积V₀=(7.119±0.007) cm³/mol，密度ρ₀=(7.981±0.008) g/cm³；在20.9 GPa附近出现bcc→hcp结构相变，两相共存压力区约10 GPa，在此区域内有晶面间距d(002)_hcp=d(110)_bcc，且原子平面(002)_hcp//(110)_bcc，hcp相比bcc相体积减小(0.33±0.02) cm³/mol；高压相hcp结构的晶格参数比值c/a=1.608±0.004；相变后原子配位数的增加使得hcp相(002)平面内及(002)平面间的最近邻原子间距比bcc相最近邻原子间距分别增大约1.6%和0.5%；用Murnaghan状态方程对实验数据进行最小二乘法拟合，得到bcc相B₀=(130±13) GPa，B₀'=12.6±0.5；hcp相V₀=(6.62±0.04) cm³/mol，B₀=(243±21) GPa，B₀'=6.8±0.3；对于该合金的bcc→fcp相变时的结构转变机制做了详细的讨论。     

Cr^4＋：YAG,Cr^4＋：Mg2SiO4近红外荧光辐射温度特性研究

测量了Ｃｒ＾４＋，ＹＡＧ、Ｃｒ＾４＋，Ｍｇ２ＳｉＯ４晶体在室温和液氮温度下的荧光光谱，吸收光谱和激发态寿命，讨论了温度变化时，两种晶体中Ｃｒ＾４＋近红外辐射积分强度变化与激光发态寿命变化的关系，得出结论：在７７Ｋ￣３００Ｋ范围内，Ｃｒ＾４＋的＾３Ｔ２能级荧光辐射截面本身受温度影响不大，Ｃｒ＾４＋辐射荧光的变化，主要是由无辐射弛豫速率随温度变化而引起的。     

Mössbauer effect study of the decagonal quasicrystal Al65Co15Cu20

The ⁵⁷Fe Mössbauer effect study at 5.0 K and in an external magnetic field of 9.0 T on a high-quality stable decagonal quasicrystal Al₆₅Co₁₅Cu_19.9Fe_0.1 is presented. It is shown that the iron atoms are located in two distinct classes of sites. The values of the principal component of the electric field gradient tensor and the asymmetry parameter at these sites are, respectively, ?1.90(10)?×?10²¹ V/m², 0.97(15) and ?3.95(12)?×?10²¹ V/m², 0.00(17).     

微脉冲电子枪的初步实验研究

给出了微脉冲电子枪的模拟计算及其初步实验结果. 该电子枪采用铜铝镁合金作为冷阴极材料, 在以磁控管作为微波功率源的出束实验中得到了100mA/cm²的电流密度.实验结果与次级电子倍增解析计算和SEEG程序的模拟计算结果基本符合, 初步验证了微脉冲电子枪的基本原理, 为今后实验中得到更大的电流密度打下了基础.     

3004铝合金“反常”锯齿屈服现象的研究

在应变速率为5.56×10^-5s^-1—5.56×10^-3s^-1的范围内，在不同温度下(从223K至773K)，对3004铝合金进行系列拉伸试验，探索其锯齿屈服规律；通过激活能的计算、内耗研究、微观组织观察和能谱分析，探讨锯齿屈服的机理与物理本质.结果表明，3004铝合金在形变过程中会出现动态应变时效现象；发现了一种“反常”的锯齿屈服现象：在出现锯齿屈服的温区内，存在锯齿屈服临界应变量转变温度T_t， 关键词： 动态应变时效 锯齿屈服 铝合金 内耗