Xe8+离子双电子复合速率系数的理论研究

利用基于全相对论组态相互作用理论的FAC程序包, 详细研究了温度在0.1~1650 eV范围内Xe8+离子的双电子复合(DR)过程。 通过比较4s, 4p和4d壳层电子激发的双电子复合速率系数, 发现温度在10 eV以上时, 内壳层4p电子激发的双电子复合速率数对总双电子复合速率系数有很重要的贡献, 而4s电子激发对总双电子复合速率数贡献小于7.5%。 给出了△n=0, 1和2 三类芯激发对总双电子复合速率系数的贡献以及自由电子俘获到不同主量子数的双电子复合速率系数, 发现△n=2的芯激发和n′＞15的DR速率系数对总DR速率系数的贡献也很重要。 进一步给出了△n=0, 1和2 三类芯激发和总DR速率系数的拟合参数, 拟合结果和计算值符合, 偏差小于1%。 通过对双电子复合、 辐射复合以及三体复合速率系数的比较得知, 在温度高于1 eV时, DR过程是Xe8+离子的主要复合过程。Based on the fully relativistic configuration interaction method, theoretical calculations are carried out for the dielectronic recombination (DR) rate coefficients of Xe8+ ions in the temperature region from 0.1 to 1 650 eV. The comparison of the DR rate coefficients from 4s, 4p and 4d subshell excitations shows that 4d subshell excitation dominates in the whole temperature region. The contribution from 4p subshell excitation is very important at temperature above 10 eV and the contributions from 4s subshell excitation is lower than 7.5% in the whole temperature region. Similarly, the comparison of the DR rate coefficients through △n=0, 1 and 2 core excitation shows that the contribution from △n=2 core excitation can not be neglected, the contributions from n′＞15 can also not be neglected. The DR rate coefficients of △n=0, 1 and 2 core excitation and the total DR rate coefficients are fitted with some parameters, which are in good agreement with theoretical calculations values (within 1% difference). The total DR rate coefficients are greater than radiative recombination (RR) and three body recombination (TBR) rate coefficients at temperature above 1 eV. Therefore, the DR process can strongly influence the ionization balance of laser produced xenon plasmas.     

苦豆子不同生育时期矿质元素分析

应用ICP-AES等技术,研究了苦豆子常量、微量矿质元素含量、各部位吸收比例和不同时期的矿质元素需求量。结果显示:(1)成熟期苦豆子常量矿质元素比约为N∶K∶Ca∶Mg∶P∶Na=11.91∶8.27∶7.54∶1.02∶1.00,微量矿质元素比值约为Fe∶Zn∶B∶Cu∶Mn=28.91∶2.12∶1.40∶1.18∶1.00;(2)各器官矿质元素含量因生育时期存在差异,微量元素在营养期茎中总量最高占全株总量的45.6%,而在成熟期种子中最高占全株总量的36.7%。(3)苦豆子在营养期需肥最多,盛花期次之,盛荚期最少。     

基于复杂度分析logistic映射和Lorenz模型的研究

采用三次粗粒化方法得到了logistic映射和Lorenz模型的符号序列，运用动态非线性时间序 列分析方法——Lemper-Ziv复杂度，分别对两组符号序列进行了对比分析.对于logistic映 射，其复杂度反映了时间序列的演化；Lorenz模型三个分量的复杂度序列都具有混沌性质， 即由许多振幅非常接近而长度完全不同的循环所组成，反映了Lorenz模型内在的准周期特性 .进一步研究发现，当取不同的窗口长度时，复杂度序列的特征基本相同，并且复杂度反映 了时间序列的时空特性.因此，可以借助复杂度的计算来反演观测资料的动力学结构. 关键词： 三次粗粒化 Lemper-Ziv复杂度 logistic映射 Lorenz模型     

Interplay of Rashba effect and spin Hall effect in perpendicular Pt/Co/MgO magnetic multilayers

The interplay of the Rashba effect and the spin Hall effect originating from current induced spin–orbit coupling was investigated in the as-deposited and annealed Pt/Co/MgO stacks with perpendicular magnetic anisotropy. The above two effects were analyzed based on Hall measurements under external magnetic fields longitudinal and vertical to dc current,respectively. The coercive field as a function of dc current in vertical mode with only the Rashba effect involved decreases due to thermal annealing. Meanwhile, spin orbit torques calculated from Hall resistance with only the spin Hall effect involved in the longitudinal mode decrease in the annealed sample. The experimental results prove that the bottom Pt/Co interface rather than the Co/MgO top one plays a more critical role in both Rashba effect and spin Hall effect.     

利用连续渗流理论构造股市指标波动模型及其讨论

本文引用连续渗流理论构造了股票市场指数波动模型,得到其特征函数收敛于Levy过程这一结论.并且在模型中也体现出了市场波动的"宽尾"现象.     

具有Banach代数的半序锥b-度量空间的一类改进（英文）

The purpose of this paper is to improve some famous theorems for contractive mapping from ρ(α + β) ∈ [0,1/s) to ρ(α + β) ∈ [0, 1) in ordered cone b-metric spaces over Banach algebras with coefficient s ≥ 1(ρ(x) is the spectral radius of the generalized Lipschitz constant x). Moreover, some similar improvements in ordered cone b-metric spaces are also obtained, which from α + β∈ [0,1/s) to α + β∈ [0, 1). Some examples are given to support that our new results are genuine improvements and generalizations.     

双波长高灵敏度Bragg光纤光栅压力传感器

裸光纤光栅压力灵敏度只有 -2. 05×10-6 /MPa,这样并不能将其用于低压力范围内的测量 本文改进了封装结构,利用金属管结构对光纤光栅部分封装,制作成双波长高灵敏度光纤光栅压力传感器 其压力灵敏度在 0~0. 44MPa的范围内可达-2. 44×10-3 /MPa,是裸光栅的 1200倍,大大提高了光纤光栅压力传感的灵敏度 采用自行研制的Bragg光纤光栅,其反射波长为 1558. 00 nm,峰值反射率为 99% 封装后的Bragg光纤光栅位于铜管的轴心,将其一部分 (约光纤光栅的二分之一 )封装到长 25mm,外径 10mm厚为 0. 8mm的铜管内 室温为 18℃时将封装好的光…     

波长间隔可调的可开关双波长掺铒光纤激光器

对两种波长间隔可调的可开关双波长掺铒光纤激光器结构进行了实验研究。一种结构应用保偏光纤中布拉格光栅作为波长选择器件，另一种结构则利用侧向压力下的常规单模光纤光栅作为波长选择器件。两种结构均利用了光纤光栅的双折射特性。在室温下，通过调整偏振控制器的状态可使两激光器工作在稳定的双波长状态或在两单波长之间转换。通过改变加在光纤光栅上侧向应力的大小和方向，可有效控制双波长激射的波长间隔。     

支持、扶植、宣传，让《通讯》扎根、开花、结果

《国际物理教育通讯》已正式创刊发行。由于它能准确地传递国际物理教育信息．及时地介绍和推荐各国物理教育的先进思想、方法和手殷等，它将对我国物理教育及改革产生深远的影响，它是我国物理教师及有关工作的良师益友。     

Pressure-induced phase transitions of multiferroic BiFeO3

Pressure-induced phase transitions of multiferroic BiFeO3 have been investigated using synchrotron radiation X-ray diffraction with diamond anvil cell technique at room temperature. Present experimental data clearly show that rhombohedral （R3c） phase of BiFeO3 first transforms to monoclinic （C2/m） phase at 7 GPa, then to orthorhombic （Pnma） phase at 11 GPa, which is consistent with recent theoretical ab initio calculation. However, we observe another peak at 2θ=7° in the pressure range of 5-7 GPa that has not been reported previously. Further analysis reveals that this reflection peak is attributed to the orthorhombic （Pbam） phase, indicating the coexistance of monoclinic phase with orthorhombic phase in low pressure range.