对卫星近日点旋进现象的分析——"地球的扁率对卫星运动的影响"一文的疏忽

指出了一篇相关文献中的疏漏,讨论了卫星近日点的旋进现象,得出了在一般情况下卫星近日点旋进的快慢程度与近日点本身所处的位置有关的结论.     

A fast directional algorithm for high-frequency electromagnetic scattering

This paper is concerned with the fast solution of high-frequency electromagnetic scattering problems using the boundary integral formulation. We extend the O(N log N) directional multilevel algorithm previously proposed for the acoustic scattering case to the vector electromagnetic case. We also detail how to incorporate the curl operator of the magnetic field integral equation into the algorithm. When combined with a standard iterative method, this results in an almost linear complexity solver for the combined field integral equations. In addition, the butterfly algorithm is utilized to compute the far field pattern and radar cross section with O(N log N) complexity.     

槲皮素包裹修饰硅包银纳米颗粒作为荧光传感器对铜离子的识别作用

制备了一种基于天然产物槲皮素接枝硅包银核壳结构的纳米荧光传感器(Ag@SiO₂@Qc),对铜离子具有好的选择性和灵敏性。Ag@SiO₂@Qc与Cu2+离子结合后,荧光发射强度发生猝灭,并且可通过荧光滴定光谱得到了荧光滴定曲线：y = -32.864x+587.59(R2=0.998),其线性范围分别为：3×10-7~4.8×10-6 mol·L-1,最低检测限为1.0×10-7 mol·L-1。并且将Ag@SiO₂@Qc应用于环境中水样的检测结果的准确度好,精密度高,而且更加环保、方便、快捷,具有很大发展潜力与应用价值。     

LIBS/Raman光谱对称零面积变换自动寻峰方法研究

自动寻峰是进行光谱原位探测、实时自动分析的必要环节,对拓展光谱分析技术到长期海洋监测、石油录井等应用领域具有重要意义。该研究以实验室中获得的LIBS/Raman光谱数据,对Gaussian,Lorenz,Voigt三种线型函数构建的对称零面积变换函数进行了比较研究。结果证明各个光谱峰都存在一个最优的对称零面积变换函数,但三种变换函数在各自的最优化参数下获得的峰位、峰宽一致;以实验室中LIBS和Raman光谱定量实验数据对该方法的测试还证明,对称零面积变换寻峰方法对信号的大范围动态变化适应性强,弱峰识别能力达到或优于人工识别水平,有望应用于将来的LIBS/Raman自动原位分析中去。     

基于自由体积理论及跨接方程的黏度推算模型

结合自由体积理论黏度模型与跨接方程,本文建立了一个适用于从气相到液相且包含临界区在内的黏度推算模型。以水为研究对象,对其对比密度ρ_r(0.01～2.57)、对比温度T_r(0.46～1.12)范围内的黏度进行了计算,计算值与文献实验值的相对偏差绝对平均值为1.81%,近临界区域相对偏差绝对平均值为4.6%。与现有的自由体积理论黏度模型相比,本文建立的黏度推算模型显著提升了近临界区域黏度的计算精度。     

Heat Transport of Electron-Doped Cobaltates

Within the t-J model, the heat transport of electron-doped cobaltates is studied based on the fermionspin theory. It is shown that the temperature-dependent thermal conductivity is characterized by the low-temperature peak located at a finite temperature. The thermal conductivity increases monotonously with increasing temperature at low-temperatures T 〈 0.1 J, and then decreases with increasing temperature for higher temperatures T 〉 0.1 J, in qualitative agreement with experimental result observed from NaxCoO2.     

稀有衰变B0(Bs)→γv(-v)分支比的计算

在标准模型中,三体稀有衰变B0(Bs)→γv(-v)只有通过箱图和企鹅图才可以发生.这个过程对于确定B介子的衰变常数及其波函数有着较重要的物理意义,由于这些衰变道的分支比较小,因此也是探测新物理理论的比较好的场所.利用B介子强衰变确定的波函数,得到B0(Bs)→γv(-v)的分支比的数量级是10-9(10-8),这些结果可以在未来的实验上得到检验.     

Controllable synthesis of high aspect ratio Mg_2B_2O_5 nanowires and their applications in reinforced polyhydroxyalkanoate composites

Highly pure magnesium borate （Mg2B2O5） nanowires with an average diameter of - 30 nm, an average length of 15 μm, and a high aspect ratio of - 500 have been synthesized on a large scale via a two-step method. MgBO2（OH） nanowires with high aspect ratios were first prepared via a PVP-assisted hydrothermal technique. Using these nanowires as precursors, single crystalline Mg2B205 nanowires were synthesized by post-annealing treatment at a relatively low temperature of 700 ℃. The important effect of the MgBO2（OH）-Mg2B2O5 conversion process on the morphology of the Mg2B2O5 nanowires was investigated and it was indicated that the recrystallization process plays an important role in the protection of the one-dimensional （1D） nanostructure. Moreover, the rigidity and the toughness of the Mg2B2O5 nanowire- reinforced PHA composites were tremendously improved compared to those of the pure PHA. Our results demonstrate the effectiveness of Mg2B2O5 nanowires for reinforcement applications in polymer composites.