FAAS与化学计量学方法用于食品分类及相关性

采用火焰原子吸收光谱法测定常见谷物及红枣中5种金属元素含量。运用化学计量学方法中聚类分析（HCA）、主成分分析（PCA）及对应分析（CA）对其进行分类对比研究,结果表明FAA S结合化学计量学方法用于食品分类研究,为食品类别分析工作提供简单、科学的数据处理方法。     

量子阱在沿其平面方向偏振太赫兹波驱动下子带间光吸收

利用半导体布洛赫方程,讨论了量子阱在沿其平面方向偏振的太赫兹场驱动下的光学吸收谱。研究结果揭示了半导体量子阱在沿平面方向偏振的强太赫兹场驱动下吸收谱的一些新奇效应,如主吸收的太赫兹边带、动态弗兰兹-凯尔迪什效应。太赫兹场的频率及其相位对探测场吸收谱的影响也很显著。     

Cu-MCM-41介孔分子筛中不同价态铜上的吸附性能研究

合成了不同铜含量的Cu-MCM-41，高温还原后仍具有良好的介孔结构。孔壁中的铜容易被H₂还原为Cu(0)。通过在氦气流中加热，可以导致孔壁中的Cu(II)还原为Cu(I)。MCM-41中不同价态的铜具有不同的吸附性能：Cu(0)强烈吸附O₂，吸附热高达427 kJ·mol^-1；Cu(I)在室温下几乎不吸附O₂，表明Cu(I)在室温下较稳定；而Cu(I)在对CO与C₂H₄的吸附中，除了CO的吸附热与Cu(0)的相近外，所生成的吸附热与吸附量均较高。红外光谱也表明，Cu(I)比Cu(0)更容易吸附CO与C₂H₄。C₂H₄仅仅以π-键键合在Cu(0)表面，而在Cu(I)表面上却是以di-σ和π-键键合，由于di-σ键较强，使得C₂H₄在Cu(I)上具有较高的吸附热。     

A full numerical calculation of the Franz--Keldysh effect on magnetoexcitons in a bulk semiconductor

We have performed a full numerical calculation of the Franz--Keldysh (FK) effect on magnetoexcitons in a bulk GaAs semiconductor. By employing an initial value method in combination with the application of a perfect matched layer, the numerical effort and storage size are dramatically reduced due to a significant reduction in both computed domain and number of base functions. In the absence of an electric field, the higher magnetoexcitonic peaks show distinct Fano lineshape due to the degeneracy with continuum states of the lower Landau levels. The magnetoexcitons that belong to the zeroth Landau level remain in bound states and lead to Lorentzian lineshape, because they are not degenerated with continuum states. In the presence of an electric field, the FK effect on each magnetoexcitonic resonance can be identified for high magnetic fields. However, for low magnetic fields, the FK oscillations dominate the spectrum structure in the vicinity of the bandgap edge and the magnetoexcitonic resonances dominate the spectrum structure of higher energies. In the moderate electric fields, the interplay of FK effect and magnetoexcitonic resonance leads to a complex and rich structure in the absorption spectrum.     

栝楼瓤黄色素提取及其稳定性与抗氧化活性研究

以“皖蒌9号”栝楼瓤为试验材料,采用超声波辅助法及Box-Behnken中心组合设计,以栝楼瓤黄色素吸光度为指标,利用响应面法优化,探索了栝楼瓤黄色素的最佳超声提取工艺。此外,为研究其稳定性,利用DPPH^·和FRAP法测定栝楼瓤黄色素体外抗氧化活性。结果表明,栝楼瓤黄色素最佳超声提取条件为：乙醇体积分数95%,料液比1∶40 g·mL^-1,提取温度60℃。Fe³⁺金属离子与光照能显著降低栝楼瓤黄色素的稳定性;栝楼瓤黄色素具有抗氧化能力,对DPPH^·有清除作用,其IC₅₀ 为9.998 mg·mL^-1,并对Fe³⁺具有还原能力。上述研究成果可为栝楼瓤黄色素资源开发和利用提供科学依据。     

量子阱在沿其平面方向偏振太赫兹波驱动下子带间光吸收

利用半导体布洛赫方程,讨论了量子阱在沿其平面方向偏振的太赫兹场驱动下的光学吸收谱。研究结果揭示了半导体量子阱在沿平面方向偏振的强太赫兹场驱动下吸收谱的一些新奇效应,如主吸收的太赫兹边带、动态弗兰兹-凯尔迪什效应。太赫兹场的频率及其相位对探测场吸收谱的影响也很显著。     

Field-Free Orientation of Molecules with Small Permanent Dipole Moments by Using a Train of Half-Cycle Pulses

We present a scheme aiming at the field-free orientation of molecules with smaller permanent dipole moments under the framework of the half-cycle pulse (HCP) method. Taking the HCCCI molecule as an example, we show that a train of identical HCPs with special time intervals can considerably raise the level of the orientation. The scheme is analytically interpreted in terms of intermittent Rabi oscillations by referring to a simplified two-state model.     

1,4,7,10-四氮杂环十二烷:有前途的储氢媒介

运用密度泛函理论(DFT)的B3LYP方法对常见的大环胺类化合物1,4,7,10-四氮杂环十二烷(cyclen)进行结构优化;进而分析了其前线分子轨道和自然键轨道布居(NBO),并确定了吸附的活性点.通过在cyclen的活性点周围放置H2,研究了其储氢性能.结果表明,1,4,7,10-四氮杂环十二烷是一种很有前途的储氢...     

徐长卿中药中丹皮酚含量的测定

采用紫外分光光度法测定了徐长卿中药中丹皮酚的含量。丹皮酚在1—8μg/mL具有良好的线性关系,徐长卿中丹皮酚含量为0.9676%,平均加标回收率为101.21%。该方法简便、快捷、准确、重现性好,可作为检测徐长卿中丹皮酚含量的一种好方法。