Gamma decay of the lowly excited states of 189Re

189W activities were produced via the 192Os(n, α) reaction using irradiation of isotopically enriched 192Os metallic powder of ～100 mg/cm2 with 14 MeV neutrons. The X-γ and γ-γ coincidence measurements were made so as to obtain γ rays from 189W decay and its coincidence relations. A new simple decay scheme of 189W including three γ rays of 210.2, 229.6 and 260.2 keV is proposed. Two new levels of 189Re at 470.4 and 489.8 keV are assigned.     

Carnot群上一类半线性方程的Liouville型定理

本文研究了Carnot群上一类具有超线性非齐次项的半线性次Laplace方程非负解的存在性问题.结合Birindelli等[4]在Heisenberg群上利用积分不等式研究解的方法和拟齐性分析技巧,给出了此类方程在Carnot群上的一类Liouville型定理.     

非线性主成分在课堂教学评估体系中的应用

介绍了Box-C ox、L og it等非线性变换及非线性主成分的概念,并利用非线性主成分来构造教学评估体系中的权系数,和线性主成分相比,我们得到了较好的结果.     

Influence of Growth Parameters of Frequency-Radio Plasma Nitrogen Source on Extending Emission Wavelengths from 1.31 μm to 1.55 μm GaInNAs/GaAs Quantum Wells Grown by Molecular-Beam Epitaxy

High （42.5%） indium content GaInNAs/GaAs quantum wells with room temperature emission wavelength from 1.3μm to 1.5μm range were successfully grown by Radio Frequency Plasma Nitrogen source assisted Molecular Beam Epitaxy, The growth parameters of plasma power and N2 flow rate were optimized systematically to improve the material quality. Photoluminescence and transmission electron microscopy measurements showed that the optical and crystal quality of the 1.54μm GaInNAs/GaAs QWs was kept as comparable as that in 1.31 μm.     

新型光交联互穿网络体系的合成与非线性光学性能

设计合成了侧链上接有肉桂酸酯基团功能化聚合物(E51-DO3-C)和侧链同时含有环氧基团和偶氮苯生色团的功能化低聚物(PPGF-DO3-50),这两种功能化聚合物可分别以环加成反应和阳离子光引发机制进行交联反应形成先交联IPN体系,研究了E51-DO3-C、PPGFDO3-50体系和光IPN体系的极化交联后材料的二阶非线性光学(NLO)性能。研究含DO3生色团的酚醛环氧甘油醚低聚体在BDS·2PF_6阳离子光引发下的光交联过程以及NLO性能,非线性光学系数d_(33)值稳定性较差。利用这两种体系的相容性,设计获得了复合物E51-DO3-C/PPGF-DO3-50,其d_(33)值稳定性有显著提高,室温下30天后d_(33)值保持初值的80％左右。     

光折变晶体Ce:BaTiO3电光和压电系数的测量

用干涉仪的方法测量了Ce:BaTiO₃晶体的低频电光系数和压电系数．排除压电效应对光通过晶体引起相位的变化，得到低频下经极化的Ce:BaTiO₃单晶的电光系数r₄₂=1945±220pm/V和r₁₃=11.8±1pm/V．从而，为研究Ce:BaTiO₃晶体的光折变效应和理论计算提供了精确的线性电光系数 关键词：     

α-Fe2O3气敏材料制备及掺杂效应近期发展

本文综合介绍了α－Ｆｅ２Ｏ３气敏材料近年来在制备方法（含影响因素）、防团聚技术、掺杂效应（含气敏机理）上的研究新进展，提出了今后气敏传感器研究及改进方向。     

Role of Interactions in Electronic Structure of a Two-Electron Quantum Dot Molecule

We have studied a two-electron quantum dot molecule in a magnetic field. The electron interaction is treated accurately by the direct diagonalization of the Hamiltonian matrix. We calculate two lowest energy levels of the two-electron quantum dot molecule in a magnetic field. Our results show that the electron interactions are significant, as they can change the total spin of the two-electron ground state of the system by adjusting the magnetic field between S = 0 and S = 1. The energy difference AE between the lowest S = 0 and S = 1 states is shown as a function of the axial magnetic field. We found that the energy difference between the lowest S = 0 and S = 1 states in the strong-B S = 0 state varies linearly. Our results provide a possible realization for a qubit to be fabricated by current growth techniques.     

流动注射-化学发光法测定B族维生素

B族维生素都是水溶性维生素,是所有人体组织必不可少的营养素,是食物释放能量的关键.它们在人体中起协同作用,调节新陈代谢,维持皮肤和肌肉的健康,增进免疫系统和神经系统的功能,促进细胞生长和分裂(包括促进红血球的产生,预防贫血发生).缺乏维生素B会有视力疲劳、角膜充血、口角炎、胃肠蠕动无力、消化不良等症状,从而导致应对压力的能力衰退,甚至引发神经炎.