MAGNETIC FIELD EFFECT OF THE EUROPIUM a8S7/2-z6P7/2 LINES

The magnetic field effect of a⁸S_7/2-z⁶P_7/2 lines of ¹⁵¹Eu and ¹⁵³Eu in magnetic fields up to 66.7 mT has been studied by using laser atomic beam spectroscopy. The Zeeman level structures of the europium a⁸S_7/2 and z⁶P_7/2 states in magnetic fields were discussed. The location and intensity of the measured Zeeman transition lines were found in good agreement with the theoretical results.     

Relativistic calculations of 3s2 1S0-3s3p 1P1 and 3s2 1S0-3s3p 3P1,2 transition probabilities in the Mg isoelectronic sequence

Using the multi-configuration Dirac-Fock self-consistent field method and the relativistic configuration-interaction method,calculations of transition energies,oscillator strengths and rates are performed for the 3s 2 1 S 0-3s3p 1 P 1 spinallowed transition,3s 2 1 S 0-3s3p 3 P 1,2 intercombination and magnetic quadrupole transition in the Mg isoelectronic sequence(Mg I,Al II,Si III,P IV and S V).Electron correlations are treated adequately,including intravalence electron correlations.The influence of the Breit interaction on oscillator strengths and transition energies are investigated.Quantum electrodynamics corrections are added as corrections.The calculation results are found to be in good agreement with the experimental data and other theoretical calculations.     

过渡族元素对非晶态Nd15Fe79B6合金磁性的影响

本文讨论了用熔态急冷法制备的非晶态Nd₁₅Fe₇₉B₆合金中,掺杂Nb,V,Cr,Mn,Co,Ni和Cu等元素后,对磁矩、居里温度及晶化温度的影响。还用穆斯堡尔谱估计了掺杂后样品内场的变化,并作了合理的解释。 关键词：     

YBa2Cu3O7超导管内磁场与外磁场的关系

本文报道了当外磁场H_e较低时(H_e<4H_rm,其中H_rm是超导管的最大捕获磁场),超导管的内磁场H_i与时间及外磁场的关系可表示为H₀+B₀(lnt+1-exp(-t/τ)),式中B₀Int与磁通蠕动有关,B_c(1-exp(-t/τ))与外磁场引起的磁通扰动有关。扰动随时间很快衰减.H₀,B₀及1/τ随外磁场增加,在H_e>H_rm时,这几个量增加较大。当直流外磁场H_e<1/2H_rm时,超导管可将其完全屏蔽,对交流场不能完全屏蔽,但其屏蔽效果仍优于最好的金属屏蔽筒。 关键词：     

Experimental generalized oscillator strengths of the 61S0→61P1-excitation of barium

Experimental generalized oscillator strengths f(K²) for excitations of the 6¹P₁ state of Ba, measured at 200 eV and 300 eV, are compared with theoretical data obtained by Kim and Bagus. Theoretical and experimental data agree at K² < 0.3 a.u., but differ significantly at greater K².     

Regarding the 21S0 and 23S1 multiplets

<正>This paper discusses the masses and possible members of 2¹S₀ and 2³S₁ meson multiplets in the framework of meson-meson mixing and Regge phenomenology.For the 2¹S₀ meson nonet,K^*（1460） may be the observed state of the 2¹S₀ isodoublet with a mass of 1400 MeV and the mass ofω（1420） is 1412 MeV.For the 2³S₁ meson nonet,K^*（1410） seems too light to be the 2³S₁ ns member.The fact that the agreement between the present findings and those given by experiments and other different approaches is satisfactory implies that the assignments in this paper may be reasonable.     

EFFECT OF THE SUBSTITUTION OF Ga ON THE STRUCTURE AND MAGNETIC PROPERTIES OF Dy2Fe17 COMPOUND

Dy₂Fe_17-xGa_x (x = 0,1,2,3,4, 5 and 6) compounds were prepared by arc melting. These compounds are of single phase, having a hexagonal Th₂Ni₁₇-type structure fox x=0 and rhombohedral Th₂Zn₁₇-type structure for x≥1. The substitution of Ga for Fe in the Dy₂Fe₁₇ leads to a linear increase of unit-cell volumes. The saturation magnetization M_s at 1.5K is found to decrease linearly with increasing Ga concentration, from 65emu/g for x= 0 to 5emu/g for x = 6; and the Fe magnetic moment μ_Fe is almost independent of Ga concentration. The Curie temperature T_C is found first to increase with increasing Ga content x, and goes through a maximum value of 559 K at about x = 3, then decreases. The sharp increase of T_C at lower Ga content may result from the increase of unit cell volumes. Dy₂Fe_17-xGa_x compounds with x≤5 exhibit easy plane anisotropy at room temperature, and those with x = 6 possess easy-axis.     

NCl（a^1△）／I（^2P3／2）传能体系的实验研究

利用微波放电C12／He等离子体作为Cl源，对反应NCl(a^1△) I(^2P3/2)→NCl(X^3∑) I(^2P3/2)进行了实验研究，得到了较大的I(^2P3/2)自发辐射荧光信号，检测到NCl(a^1△，b^1∑)自发辐射荧光光谱在存在少量I(^2P3/2)下发生的显著变化，其中NCl(a^1△)自发辐射荧光信号降低，同时由于I(^2P3/2)的作用，NCl(b^1∑)自发辐射荧光信号大幅度增加。在考察各反应气体流量对I(^2P3/2)自发辐射荧光信号的影响时发现，在本次实验条件下，各种气体的最佳流量：He为1—4mmol/s，I2为0．01—0．03mmol/s，Cl2为1．0mmol/s左右，而HN3流量略大于Cl2流量时信号升高幅度开始变缓，约为Cl2流量的两倍时信号不再有显著的变化。     

POWDER NEUTRON DIFFRACTION STUDIES OF THE CRYSTALLOGRAPHIC AND MAGNETIC STRUCTURE OF Ho2Fe9Ga8 and Ho2Fe9Ga6AI2

The crystallographic and magnetic structures of Ho₂Fe₉Ga₈ and Ho₂Fe₉Ga₆AI₂ were studied by powder neutron diffraction at room temperature. The atom fractional occupancies of Ga and Al and the magnetic moments of Ho and Fe were obtained by using Rietveld analysis program. The magnetic structures of the two samples show an easy-axis anisotropy, with the Fe magnetic moment being ferrimagneticlly coupled to those of Ho.     

La2CuO4在平行CuO2面磁场中的磁转变

本文在平均场近似下,给出一个关于在平行CuO₂面的磁场作用下,La₂CuO₄的磁转变理论。理论给出的临界磁场随温度T的变化,在定性上与实验相符。但是,从本文理论看,不存在多重临界点。简单讨论了理论和实验不符合的原因。 关键词：     

四极磁透镜的边缘场研究

本文对四极磁透镜的磁场分布和电子的输运问题进行了研究和计算。文中阐述了四极磁透镜边缘场的三种处理方法,用这三种方法计算了透镜的输运矩阵。相互比较表明,四极磁透镜的边缘场采用传统的直角边近似就可以很好地解决问题。     

一维自旋-1/2XY模型的磁场效应

本文主要利用Haldane的谐振流理论——玻色化方法研究外场中的自旋-1/2XY模型。本文首先将无磁场情况下该模型的哈密顿进行了玻色化与对角化,并单独讨论了磁场项,最后两者联合给出外磁场中一维自旋-1/2模型哈密顿的玻色化形式。在这种形式下哈密顿量中的协变问题可以通过平移费米点来解决,所以,在阿贝尔玻色化方案下对玻色场算符做了重新定义,得到一个新的协变的哈密顿,从而解决了由于扰动所带来的问题,各关联函数也随之给出;最后简单讨论了平移费米点给模型关联函数的表达式带来的变化,以及玻色化方法较之其他方法的优长。     

双钙钛矿Sr2CrWO6的磁性与输运性质研究

研究了双钙钛矿Sr₂CrWO₆的磁性和输运性质.Sr₂CrWO₆多晶在Ar气及真空气氛中经固相烧结而形成.X射线衍射分析表明主相为Sr₂CrWO₆,少量杂相为SrWO₄.热磁测量表明样品的居里温度为480K左右.电阻随温度降低而升高,类似于绝缘体,在外场5T,低温下(25K)磁致电阻(MR)可达20%,但MR随温度升高而趋于零.较大的矫顽力(5.97×1 关键词： 双钙钛矿氧化物 磁性质 磁致电阻     

随机磁场对漂移波本征模的影响

本文分析随机磁场对低频漂移波本征模的影响。计算表明,存在随机磁场可影响电子对波的响应,改变电子色散函数,在有理磁面附近(k_‖≈0处),这种变化尤大,随机场可使电子色散函数变得相当平缓,这对漂移波本征模的稳定性有很大影响。本文证明了,在足够强的(但仍是实验允许范围内的)随机磁场下,漂移波普适模可成为绝对不稳定的。     

THE INFLUENCE OF Co SUBSTITUTION ON THE MAGNETIC PROPERTIES AND THE GIANT MAGNETO-IMPEDANCE EFFECT OF (Fe1-xCox)84Zr3.5Nb3.5B8Cu1

The microstructure, magnetic properties and the giant magneto-impedance (GMI) effect of the nanocrystalline (Fe_1-xCo_x)₈₄Zr_3.5Nb_3.5B₈Cu₁ ribbons have been studied. With increasing Co concentration, the nanocrystallized grain size and volume fraction of the α-Fe(Co) phase decrease under the same annealing condition, while the coercivity H_c increases from 1.92 A/m at x=0.0 to 30.38 A/m at x=0.8. The effective permeability drops sharply with increasing Co concentration so that the GMI effect goes down. A value of more than 380% for the magneto-impedance(MI) ratio was measured at frequency f=2.5 MHz and the sensitivity can reach 0.9% (A/m)^-1 for Fe₈₄Zr_3.5Nb_3.5B₈Cu₁ ribbon. When x is equal to 0.8, the MI ratio drops to about 30% and the sensitivity only reaches a value of lower than 0.025% (A/m)^-1. The concise analysis in theory is also expounded.     

EFFECT OF ZnFe22O4 DOPING ON THE OPTICAL PROPERTIES OF TiO2 THIN FILMS

Amorphous TiO₂ thin films and ZnFe₂O₄ doped TiO₂ composite films were deposited by radio frequency magnetron sputtering. The effect of ZnFe₂O₄ doping on the optical properties of TiO₂ thin films was reported. Our results show that the absorption edge of TiO₂ thin films and composite films exhibits a blue shift with decreasing annealing temperature. The absorption edge of composite films has moved to visible spectrum range, and a very large red shift occurs in comparison with TiO₂ thin film. An enhanced photoluminescence in ZnFe₂O₄ doped anatase TiO₂ thin film at room temperature.     

CeO2/Nb2O5界面效应对提高CeO2氧敏特性的XPS研究

用射频/直流磁控溅射法制备了CeO₂/Nb₂O₅双层氧敏薄膜，利用X射线光电子能谱(XPS)，描述并解释了单层CeO₂薄膜中氧随温度变化的动力学行为，以及CeO₂/Nb₂O₅薄膜界面对氧敏特性的影响.通过对Ce3d XPS谱的高斯拟合，计算了Ce³⁺浓度并给出了判定Ce⁴⁺还原的标志.结果表明，界面效应可以提高CeO₂/Nb₂O₅薄膜中Ce⁴⁺的还原能力，使之远远高于单层CeO₂薄膜，这对薄膜的氧敏特性是极为有利的. 关键词：     

New ab initio Potential Energy Surfaces for Cl(2P3/2, 2P1/2)+H2 Reaction

采用多参考组态相互作用的计算方法和很大的基组构造了Cl+H₂反应体系的一组新的三维从头算势能面. 该势能面包含Cl+H₂体系的能量最低的三个绝热态,并在非绝热近似下转化为四个非绝热势能面. 另外,旋轨耦合矩阵元也基于Breit-Pauli Hamil-tonian计算得到. 对角化这四个非绝热势能和两个旋轨耦合矩阵元组成的全耦合Hamiltonian,得到了三个考虑旋轨耦合后的绝热势能面.基于这组新势能面的非绝热动力学计算结果与最新的实验符合得很好,很好地解释了     

MEASUREMENT OF HYPERFINE COUPLING CONSTANTS OF THE EXCITED STATES 4f7(8S07/2)6p3/2(7/2, 3/2) IN 151,153Eu+

Hyperfine structure spectra of singly ionized europium have been measured by collinear fast-ion-beam laser spectroscopy. All the spectral lines were resolved and the magnetic dipole and electric quadrupole coupling constants of the metastable and excited levels were determined.