First-Principles Study of Electronic Structure of the Laves Phase ZrFe2

We perform the ab initio calculation for obtaining the density of states and magnetic properties of ZrFe2 Laves phase compound based on the method of augmented plane waves plus local orbital The results indicate that the ferromagnetic state is more stable than the paramagnetic one, but with a slightly larger volume. The 3d - 4d exchange interactions between Fe and Zr electrons lead to the antiparallel coupling for Fe 3d and Zr 4d states, which is responsible for the ferrimagnetic ordering of the compound. The resulting magnetic moment of about 1.98μB for Fe is spatially localized near the Fe site, while around Zr a small but extended negative spin states causes a moment of about -0.44 μB. Moreover, the resulting magnetic moments with the generalized gradient approximation are more consistent with experimental values than that of the local-spin density approximation.     

Electrochemical Deposition and Properties of ZnTe Nanowire Array

Pulsed electrodeposited technique is applied to fabricate ZnTe nanowire arrays with different diameters into the anodic alumina membrane in citric acid solution. The x-ray powder diffraction, scanning electron microscopy and transmission electron microscopy indicate that the high ordered, uniform and single-crystalline nanowires have been fabricated. The optical absorption spectra of the nanowire array show that the optical absorption band edge of the ZnTe nanowire array exhibit a blue shift compared with that of bulk ZnTe, and the nonlinear current-voltage characteristic is observed.     

Flat Supercontinuum Generation at 1550 nm in a Dispersion-Flattened Microstructure Fibre Using Picosecond Pulse

The generation of a flat supercontinuum of over 80nm in the 1550nm region by injecting 1.6ps 10 GHz repetition rate optical pulses into an 80-m-long dispersion-flattened microstructure fibre is demonstrated. The fibre has small normal dispersion with a variation smaller than 1.5 （ps·nm^-1·km^-1） between 1500 and 1650nm. The generated supercontinuum ranging from 1513 to 1591 nm has the flatness of ±1.5 dB and it is not so flat in the range of several nanometres around the pump wavelength 1552nm. Numerical simulation is also used to study the effect of optical loss, fibre parameters and pumping conditions on supercontinuum generation in the dispersion-flattened microstructure fibre, and can be used for further optimization to generate flat broad spectra.     

填充式skutterudite化合物：BayFexCo4-xSb12的多步固相反应合成及结构

以Ba为填充原子,在x=0—3.0,y=0—0.7的组成范围内,用多步固相反应法合成了单相Ba_yFe_xCo_4-xSb₁₂化合物.用Rietveld方法对结构的精确化结果表明：合成的Ba_yFe_xCo_4-xSb₁₂化合物具有填充式skutterudite结构,Ba的热振动参数(B)比Sb,Fe/Co的大,表明在Ba_y关键词： 填充式skutterudite化合物 固相反应     

色散缓变光纤中宽带调制不稳定性谱的产生

本文报道色散缓变光纤中调制不稳定性效应研究.从非线性Schrodinger方程出发,获得了增益谱与纵向色散变化参量和光纤传输距离的一般关系.研究发现,色散缓变光纤中调制不稳定性的增益谱较常规光纤中的宽得多.调节光纤色散纵向变化参量,可以得到较宽的增益谱.该文的研究结果为光纤中利用调制不稳定性产生超短孤子脉冲提供了理论根据.     

ABeF_3(A=Na,K,Rb,Cs)体系中Eu~(2+)的f→f跃迁发射

合成了一系列Eu~(2+)激活的碱金属氟化物一氟化铍复合氟化物(ABeF_3∶Eu~(2+))磷光体。观察到了f→f跃迁引起的Eu~(2+)很强的锐线发射,尖峰位于360nm附近。随碱金属原子电负性减小,峰值向短波方向稍有移动。得到了与A.S.T.M一致的结晶学数据。穆斯堡尔谱和电子能谱结果表明,体系中有少许Eu~(3+)与Eu~(2+)共存。     

新显色剂对羧基苯基重氮氨基偶氮苯的合成及与镉显色反应的研究

本文报道了新色剂对羟基苯基重氮氨基偶氮苯的合成。     

稀土—4—（2—吡啶偶氮）间苯二酚螯合物的高效液相色谱分离和测定

本文讨论了反相离子对液相色谱法分离和检测稀土-4-(2-吡啶偶氮)间苯二酚螯合物的各种条件,在12 min内完成了9种稀土螫合物的分离,校正曲线的线性范围是(ppm):La(0.01～3.20),Ce(0.03～2.8),Pr(0.06～3.5),Nd(0.05～3.8),Sm(0.01～3.0),Eu(0.05～3.4),Tb(0.02～3.0),Ho(0.01～3.4),Er(0.06～4.0).变异系数小于1.2％.     

AB5型储氢合金的高倍率放电性能及机制

本文研究了储氢合金表面处理，粒度分布，稀土组成和添加剂硼对储氢合金高倍率放电性能的影响及机制的探讨。采用物理方法和化学方法对储氢合金进行表面处理，提高了合金表面电化学反应速度，同时促进了氢原子在合金本体中的扩散，从而改善了合金的活化性能、放电容量和高倍率放电能力。储氢合金粉粒度太粗和太细都使合金电极阻抗增大，导致放电容量和高保率放电能力下降，而且大电流放电平台也较低，选择合适的储氢合金粉粒度分布既可提高合金的活性和放电容量又能改善合金高倍率放电能力。随着合金中La含量的增加和Ce含量的减少，提高了合金的表面活性，使合金的大电流放电性能得到改善。储氢合金中加入元素B，使合金易粉化并形成少量的第二相，不但改善了合金的活性和放电容量而且显著地提高了合金高倍率放电能力。     

Gain of harmonic generation in high gain free electron laser

In a planar undulator employed free electron laser (FEL), each harmonic radiation starts from linear amplification and ends with nonlinear harmonic interactions of the lower nonlinear harmonics and the fundamental radiation. In this paper, we investigate the harmonic generation based on the dispersion relation driven from the coupled Maxwell-Vlasov equations, taking into account the effects due to energy spread, emittance, betatron oscillation of electron beam as well as diffraction guiding of the radiation field. A 3D universal scaling function for gain of the linear harmonic generation and a 1D universal scaling function for gain of the nonlinear harmonic generation are presented, which promise rapid computation in FEL design and optimization. The analytical approaches have been validated by 3D simulation results in large range.