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介绍了一种计算HL-2M装置环向场线圈自感的简捷方法，即用多个多边形电流丝模拟环向场线圈，用两个小直线段的互感求和代替多重积分，使问题得到简化。利用HL-2A装置的放电数据拟合计算了HL-2A装置环向场线圈的自感，从而验证了方法的正确性。     

HL-2A装置真空室钛球加热电源的研制

为了更好地改善HL-2A装置真空室壁环境，利用金属钛高温升华时能吸附在真空室内壁的物理特性，在装置真空室设置了14个金属钛球。钛球升华温度约1200℃，通过给钛球灯丝通人40～50A电流加热可达到此升华温度。对此，我们设计研制了14台低压、大电流电源，给HL-2A装置真空室钛球进行加热，希望在实验中能获得更为满意的等离子体参数。     

MgB2颗粒超导体临界电流的温度特性研究

通过制备MgB2/MgO超导复合材料,获得了典型的MgB2弱连接颗粒超导体,并测量了该样品在不同温度下的Ⅰ-Ⅴ特性曲线.在Ⅰ-Ⅴ曲线中,我们发现:当电流超过临界电流时,电压随着电流先是缓慢的增长,在电流升到一定值时,电压有一个很陡的突变.我们对这一变化进行了研究,认为这是由于MgO杂质使MgB2的晶界效应增强所引起的.该样品的临界电流和温度的关系满足:jc(T)∝(1-T/Tc)1/3,利用三维Josephson结网络系统的渗流模型进行计算发现,当颗粒超导系统处于非均匀状态时,临界电流和温度满足关系式jc(T)∝(1-T/Tc)4/3,这一结果和我们的实验符合的非常好.     

Bi1.8Pb0.2Sr2Ca2Cu3O高温超导体的I—V特性研究

我们测量了Ｂｉ１．８Ｐｂ０．２Ｓｒ２Ｃａ２Ｃｕ３Ｏ高温超导体在磁场下不同温度的等温Ｉ－Ｖ曲线。观测到在等温ｌｇＩ－ｌｇＶ曲线上会同时存在正曲率和负曲率，这是通常的Ａｎｄｅｒｓｏｎ－Ｋｉｎ磁通蠕动模型和涡旋玻璃态的标度理论Ｖ∝ｅｘｐ［－（Ｊ０／Ｊ）＾Ｈ］所不能解释的。我们在蠕动模型的基础上，考虑到磁通运动时的耗散对激活能会有一个动力学的贡献，对上述现象进行了解释，并与实验进行了对比。     

Bi2-xPbxSr2Co2Oy单晶各向异性输运性质的研究

研究了不同Pb含量的Bi2-xPbxSr2Co2Oy单晶的输运行为．用A．F．Ho和A．J．Schofield提出的公式对ρc的温度依赖关系曲线进行了拟合，得到了较好的结果．我们利用小极化子理论解释了ρc的复杂行为．     

Cu-Ni包套MgB2带应力效应研究

使用电测量方法测量了用粉末套管(PIT)工艺制备的Cu-Ni包套MgB2单芯带的弹性模量E,其值与Cu及其合金的弹性模量为同一量级,还证实了在带中存在着压缩预应力.我们研究了该带在4.2K,0.5～4T磁场下弯曲成不同曲率时的Ic-B特性曲线,并且计算相应曲率时的最大应变和应力.弯曲实验显示该带材对应力较为敏感,必须改进工艺并实施机械强化.     

HL—2A装置LHCD的运行区域与驱动电流分布控制

本文利用低杂波电流驱动（LHCD）的理论和实验结果,讨论了电流驱动效率和电流分布控制与等离子体参量及入射波谱的关系,强调了波传播在确定功率沉积分布区域中的作用,并讨论了控制电流密度分布的方法,探索在HL－2A装置上实现中心负磁剪切位形的可能性。     

热处理对Li2O-Al2O3A-SiO2系统玻璃性质的影响

测量了线性升温热处理后Li2 O Al2 O3 SiO2 系统零膨胀微晶玻璃V0 2的性质变化。在一个较小的温度区间内 ,玻璃物理性质由于相变而出现显著变化。折射率增加 175× 10 -4、密度增加 0 .0 94g/cm3 、热膨胀系数降低4 1× 10 -7/℃、努普 (Knoop)硬度增加 18.6MPa、线收缩达 1.12 %。短波区透射率随着热处理温度的升高先出现下降而后再次上升。实验结果为大尺寸微晶玻璃毛坯的晶化工艺过程提供有实用意义的建议     

封离式He-N2-CO2激光器横模特性的测量与分析

利用激光光束分析仪,实时在线测量了一根He-N2-CO2封离式激光管的横模分布特性,得到了激光模式随放电电流的变化关系.实验表明该激光器在最佳工作电流时,容易形成低阶模运转,但很难获得基模运转,通过改善对称性以及加快冷却水流速可以获得基模运转.通过激光动力学过程分析了模式变化的形成原因,为大功率激光器模式控制与改善提供了一定的理论和实验借鉴.     

自由基SiH_2分子配分函数的计算

利用Gaussian03程序包,在B3P86/cc-PV5Z水平上对自由基SiH_2分子基态X~1A_1几何结构进行优化计算,得到其平衡几何结构、谐振频率和转动常数等性质参数;采用乘积近似法计算了自由基SiH_2分子基态X~1A_1从低温20 K到高温6000 K温度范围内的总配分函数.其中,转动配分函数采用WATSON的刚性转子模型,振动配分函数采用谐振子近似.然后我们把20～6000 K的温度范围划分为五个区间段,计算的总配分函数在这五个温度区间分别被拟合到一个温度T的四阶多项式,从而在每个区间均得到五个拟合系数.由这些拟合系数就可以快速、准确的获得该分子在所研究温度范围内任意温度的总的配分函数.     

Magnetic ordering in HoRu2Si2, HoRh2Si2, TbRh2Si2 and TbIr2Si2 by neutron diffraction

Neutron diffraction study of polycrystalline HoRu₂Si₂, HoRh₂Si₂, TbRh₂Si₂, and TbIr₂Si₂ was performed in the temperature range between 4.2 and 300 K. For HoRu₂Si₂ the magnetic spin alignment of a linear transverse wave mode below the Néel temperature 19 K is observed. This static moment wave is propagating along the b-axis with k=(0, 0.2, 0) and is polarized in the c-axis. The root-mean-square and maximum saturation moments per Ho atom are 9.26 and 13.09μ_B, respectively. HoRh₂Si₂, TbRh₂Si₂ an TbIr₂Si₂ are simple collinear antiferromagnets of +-+- type with Néel temperatures of (27±1), (98±2) and (72±3) K, respectively. For TbRh₂Si₂ and TbIr₂Si₂ magnetic moments are localized on RE ions only and are aligned along the tetragonal axis, while for HoRh₂Si₂ they form an angle ø = (28±3)°.     

μ+SR study of LaNi2As2, URh2Si2 and CeRh2Si2

Muon spin relaxation experiments have been carried out in the paramagnetic and magnetically ordered states of URh₂Si₂ and CeRh₂Si₂. As the magnetic structure of these compounds is well known, these measurements can help to characterise their magnetic properties probed by μSR and to understand the μSR results of the heavy fermion compounds of the same crystallographic family. Our measurements show that the muons occupy two different crystallographic sites. The spectra of URh₂Si₂ and CeRh₂Si₂ in the magnetically ordered states are very different, probably reflecting their different magnetic structures. The spectra obtained on CeRh₂Si₂ are similar to the published spectra of the heavy fermion compound CeCu_2.1 Si₂. Muon spin rotation measurements on LaNi₂As₂ indicate that the muon is diffusing at 150 K.     

13C-selective IRMPD of CBr2F2/Cl2 and CCl2F2/Br2 systems

The CO₂ TEA laser irradiation of CBr₂F₂ in the presence of Cl₂ yielded ¹³C-enriched CBrClF₂ and ¹³C-enriched CCl₂F₂ under selected experimental conditions. As the photolysis proceeded, the ¹³C concentration of CBrClF₂ decreased gradually and that of CCl₂F₂ increased up to 90% or higher. These results can be explained by the mechanism involving the secondary ¹³C-selective IRMPD of the primary product CBrClF₂. On the other hand, the carbon-containing product for a CCl₂F₂/Br₂ system was only CBrClF₂; the further IRMPD of which probably regenerated CBrClF₂ in the presence of Br₂. The decomposition probabilities of ¹²C- and ¹³C-containing molecules in both systems were measured as functions of laser line, laser fluence, and reactant pressures.     

Polar optic phonons in Hg2Cl2 and Hg2Br2

Far infrared (30–430 cm^?1) reflectivity measurements of Hg₂Cl₂ and Hg₂Br₂ single crystals have been performed in polarized light. The spectra, which are in agreement with group-theoretical predictions, were analyzed by the oscillator fitting procedure and Kramers-Kronig method. The results are compared with the existing data from other measurements and the large anisotropy of polar modes is briefly discussed. The polarization vectors of all long-wavelength symmetry modes were determined group-theoretically.     

Magnetostriction of SmMn2Ge2 and GdMn2Ge2 intermetallic compounds

Longitudinal and transverse magnetostrictions of polycrystalline samples of intermetallic compounds RMn₂Ge₂ (R=Sm or Gd) are measured in pulsed magnetic fields up to 250 kOe. It is found that linear magnetostrictive strains of about 10^?3 arise in a temperature range in which the magnetic field causes a change in the magnetic state of a manganese magnetic subsystem. The results obtained are described within the model of a two-sublattice ferrimagnet with a negative exchange interaction in the manganese subsystem in terms of a strong dependence of this interaction on interatomic distances.     

Superconductivity in LaPd_2Bi_2 with CaBe_2Ge_2-type structure

正Since the discovery of superconductivity in LaFeAsO_(1-x)F_x,the high-T_c iron-based superconductors have been extensively studied from both experimental and theoretical viewpoints [1-8]. However, the mechanism of the unconventional superconductivity is still to be resolved. To     

Structural,magnetic and neutron diffraction studies on TbFe2-TbAl2, TbCo2-TbAl2 and HoCo2-HoAl2

Both pseudobinary systems exhibit large homogeneous regions of cubic and hexagonal Laves phases. Ordering tendencies on crystallographic sites between Al and the transition metals are observed in the hexagonal type.Electron transfer to the transition metals quenches their moments so that they become nonmagnetic at high Al concentrations. The peculiarities in the mechanism of magnetization which appear in rare earth dialuminides when Al is replaced by a transition metal have been studied in detail at cryogenic temperatures.The first replacement of Al results in a decrease in saturation moment. Neutron diffraction verifies the low ordered rare earth sublattice moments and reveals the ‘lost part’ as a disordered component. Considerable magnetic hardness develops in certain regions of concentration often connected with spontaneous increases in magnetization with field. All available evidence suggests the presence of unusual domain wall effects to be responsible for this effect. High remanences develop in both the hexagonal and in the cubic structures in the intermediate region. The development of disordered magnetic components is connected either with the disorder on crystallographic sites or changes in the free electron concentration.