烷基和酰基钴化合物合成方法研究进展

总结了烷基和酰基钴化合物及其膦配体衍生物的合成方法,综述了其合成方法研究进展.指出烷基和酰基钴化合物是多种重要催化反应如氢甲酰化反应、甲醇同系化反应、酰胺羰基化反应的循环中间体;近年来,烷基和酰基钴化合物因可以催化羰基化聚合反应而引起了广泛的关注.     

烧结温度对红色长余辉发光材料Ca0.8Zno.2TiO3∶ Pr3+,Na+性能的影响

采用溶胶凝胶燃烧法合成了Ca0.8Zn0.2TiO3∶Pr3+,Na+纳米红色长余辉发光材料,利用XRD、SEM、荧光分光光度计、热释光谱仪和照度计研究了烧结温度对样品物相、形貌以及发光性能的影响.结果表明:煅烧温度为600℃时生成了CaTiO3相,当烧结温度大于700℃时,出现了Zn2TiO4相;随煅烧温度的升高,样品的晶粒逐渐变大,平均晶粒尺寸均小于100nm;不同温度下样品的激发峰位于328nm,发射峰位于613 nm,归属于P,+的1D2-3 H4跃迁;当烧结温度为800℃时,样品的初始亮度和余辉时间最佳,其分别为2000 mcd/m2和10 min(≥1mcd/m2).     

窄域上2D弱阻尼KdV方程的blow-up的研究

得到了2D的弱阻尼KdV方程在窄域上blow-up时间估计.     

Electronic Phase Separation in Iron Selenide(Li,Fe)OHFeSe Superconductor System

The phenomenon of phase separation into antiferromagnetic(AFM) and superconducting(SC) or normal-state regions has great implication for the origin of high-temperature(high-T_c) superconductivity. However, the occurrence of an intrinsic antiferromagnetism above the T_c of(Li,Fe)OHFe Se superconductor is questioned. Here we report a systematic study on a series of(Li,Fe)OHFe Se single crystal samples with T_c up to ～41 K. We observe an evident drop in the static magnetization at T_(afm) ～ 125 K, in some of the SC(T_c 38 K, cell parameter c■9.27 ?) and non-SC samples. We verify that this AFM signal is intrinsic to(Li,Fe)OHFe Se. Thus, our observations indicate mesoscopic-to-macroscopic coexistence of an AFM state with the normal(below T_(afm)) or SC(below T_c) state in(Li,Fe)OHFe Se. We explain such coexistence by electronic phase separation, similar to that in high-T_c cuprates and iron arsenides. However, such an AFM signal can be absent in some other samples of(Li,Fe)OHFe Se, particularly it is never observed in the SC samples of T_c 38 K, owing to a spatial scale of the phase separation too small for the macroscopic magnetic probe. For this case, we propose a microscopic electronic phase separation. The occurrence of two-dimensional AFM spin fluctuations below nearly the same temperature as T_(afm), reported previously for a(Li,Fe)OHFe Se(T_c ～ 42 K) single crystal, suggests that the microscopic static phase separation reaches vanishing point in high T_c(Li,Fe)OHFe Se. A complete phase diagram is thus established. Our study provides key information of the underlying physics for high-T_c superconductivity.     

依赖强度耦合的级联三能级原子系统中双模压缩真空初态场的非经典性质

运用全量子理论研究了依赖强度耦合的级联三能级原子系统中双模压缩真空初态场的压缩及量子统计性质,并讨论了初始光场的压缩参量以及原子—光场单光子失谐量对光场非经典性质的影响.     

钚气溶胶环境中惰性气体氪迁移过程研究

放射性气体的安全性问题是涉及反应堆运行中必需研究的重要问题.因此在钚气溶胶环境中,对钚材料裂变产生的放射性气体裂变产物,需要研究其在钚气溶胶环境中的迁移过程.对放射性惰性气体Kr87,Kr88的实验测量数据进行了具体分析.依据它们具有钚材料直接裂变和作为固体裂变产物子体两种来源这一物理特性,在不同的制样时间对Kr87/Kr88比值变化规律进行分析.确立了这两种来源的在钚气溶胶环境中的物理图像和迁移过程的物理模型,并与实验数据进行比较以验证模型的正确性. 关键词： 钚气溶胶 气体裂变产物 放射性Kr87/Kr88 迁移过程     

随机共振研究进展

全面介绍了随机共振的概念、机理、理论和实验研究的主要进展及研究现状，对随机共振研究的可能应用也做了富有建设意义的展望性介绍。     

真空紫外光激发下掺Pr3+铝酸盐的自陷激子对Pr3+发光的影响

研究了SrAl12 O19:Pr3+和Y3Al5O12(YAG):Pr3+在20K,77K和300K的真空紫外(VUV)光谱,二者除了表现出Pr3+特有的发射性质外,还产生了一种特殊的发射现象,即自陷激子(STE)发射,并且其随着稀土离子浓度和温度的降低而增强.还着重讨论了自陷激子对Pr3+发光的影响.     

非线性Jaynes-Cummings模型中原子偶极矩的高阶压缩

研究了非线性双光子Jaynes-Cummings(J-C)模型系统中原子偶极矩高阶压缩的时间演化特性及其产生条件。结果表明,在弱场条件下,原子偶极矩色散或吸收分量的二阶和六阶量子涨落可被周期性压缩,非线性修正项或失谐量以及热噪声对压缩程度有显著的影响。     

Soliton Solutions,Bcklund Transformations and Lax Pair for a(3 + 1)-Dimensional Variable-Coefficient Kadomtsev–Petviashvili Equation in Fluids

Under investigation in this paper is a(3 + 1)-dimensional variable-coefficient Kadomtsev–Petviashvili equation, which describes the propagation of surface and internal water waves. By virtue of the binary Bell polynomials,symbolic computation and auxiliary independent variable, the bilinear forms, soliton solutions, B¨acklund transformations and Lax pair are obtained. Variable coefficients of the equation can affect the solitonic structure, when they are specially chosen, while curved and linear solitons are illustrated. Elastic collisions between/among two and three solitons are discussed, through which the solitons keep their original shapes invariant except for some phase shifts.