超高效液相色谱-串联质谱同时测定加味左金丸中的9种有效成分

建立了同时测定加味左金丸中9种药效成分含量的超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法。采用Zorbax RRHD Eclipse Plus C18色谱柱,以含0.2%甲酸的水-甲醇为流动相进行梯度洗脱,流速0.4 mL/min,在电喷雾电离(ESI)正离子模式下,采用多重反应监测模式进行检测。结果表明,芍药苷、延胡索乙素、药根碱、小檗碱、巴马汀、吴茱萸碱、柴胡皂苷C、柴胡皂苷A、柴胡皂苷D的线性范围分别为0.025～5.0 mg/L、0.0010～2.0 mg/L、0.0023～7.2 mg/L、0.0027～28.9 mg/L、0.0023～9.1 mg/L、0.0050～1.0 mg/L、0.050～10 mg/L、0.005～1.0 mg/L、0.0075～1.5 mg/L;检出限分别为5.0、0.20、0.45、0.54、0.45、1.0、10、1.0、1.5 μg/L。9种成分的加样回收率为99.3%～105%,相对标准偏差均不大于2.6%。该法快捷、准确、重复性好,已成功用于实际样品的分析。     

Theoretical study of stereodynamics for the N+H2/D2/T2 reactions

The effects of isotopic variants on stereodynamic properties for the title reactions have been investigated using a quasi-classical trajectory method based on the first excited state NH2（I^2A＇） potential energy surface [Li Y Q and Varandas A J C 2010 J. Phys. Chem. A 114 9644]. The forward–backward symmetry scattering of the differential cross section can be observed, which demonstrates that all these reactions follow the insertion mechanism. Three angle distribution functions P（θr）, P（φr）, and P（θr, φr） with different collision energies and target molecules H2/D2/T2 are calculated. It is shown that the product rotational angular momentum is not only aligned, but also oriented along the direction perpendicular to the scattering plane. The title reaction is mainly governed by the ＂in-plane＂ mechanism through the calculated distribution function P（θr, φr）. The observable influences on the rotational polarization of the product by the isotopic substitution of H/D/T can be demonstrated.     

稳定同位素比质谱法测定苹果和浓缩苹果汁的δ13C值

用从国际原子能机构溯源得到的橄榄油标准物质[Cat No.B 2172-Batch 3130,其δ13CPDB为(-28.51±0.16)‰]作标准,应用稳定同位素比质谱法测定了苹果和苹果汁的δ13 C值,并以此确定国产苹果的δ13 C值的范围和鉴定制成的果汁的质量。苹果样品去皮后切碎,打成糊状,离心后取其上清液,在75℃加热2～3h至呈黏稠状液体,冷却至室温。此时其糖度约为70Brix。浓缩苹果汁样品是黏稠液体,其糖度一般也在70Brix左右。取2μL上述样品置于锡杯中,按方法处理后供质谱分析。标准物质的进样量为2μL。按所测得碳的稳定同位素13C与12C的比值代入所给公式计算δ13 C值。结果表明:方法的精密度较好,其相对标准偏差(n=11)均小于0.021%。根据测定结果发现,我国苹果的δ13C值在-29.1‰～-23.33‰之间。     

惯性约束聚变点火靶候选靶丸特点及制备研究进展

获得能量增益实现点火是目前激光惯性约束聚变领域研究的主要方向和标志性成果. 在点火靶的设计中有多种可能的候选靶丸,包括碳氢掺杂锗、铍掺杂铜、聚酰亚胺、 碳化硼和金刚石靶丸,其中碳氢和铍靶丸是最主要的候选靶丸.文中主要总结了几种候选靶丸的优缺点及目前研制现状.在国外,碳氢靶丸是目前点火靶的首选靶丸. 与铍靶丸相比,不存在明显的微结构缺陷,制备较容易;靶丸光学透明, 适宜于燃料分层和表征;靶丸在制备上更容易达到点火靶要求. 美国的碳氢点火靶靶丸基本达到了设计要求,这些要求包括几何尺寸、壳层密度、 壳层缺陷、表面光洁度、掺杂水平和杂质含量等.我国的点火靶靶丸研究还处在起步阶段.     

Aerosol observation in Fengtai area, Beijing

Measurements of aerosol number concentration and particulate matter with diameter less than 10 μm （PM10） mass concentrations of urban background aerosols were performed in Fengtai area, Beijing in 2006. Black carbon （BC） was collected simultaneously from the ground and analyzed to determine the particulate matter components. To satisfy the interest in continuous monitoring of temporal and spatial distribution of aerosols, the relationship between extinction coefficient （visibility） measured by lidar remote sensing and the aerosol number concentration measured from the ground was derived by using statistical method. Vertical particle number concentration profile within the planetary boundary layer could be inversed through the lidar data as well as the statistical relation.     

Effective AC and DC Responses of Nonlinear Composites at Higher Concentration

For higher concentration of inclusions, an effective medium approximation （EMA） method is used to investigate the bulk effective response of weakly nonlinear composites, which are subject to the constitutive relation of electric displacement and electric field, Dα = εαE ＋Xα｜E｜^2 E. As an example of three dimensions, under the external AC and DC electric fields Eapp = Eα（1 ＋ sinωt）, we have derived the general effective nonh＇near response of composites by the EMA method for higher concentration of spherical inclusions. Furthermore, the effective nonlinear responses at harmonics are predicted.     

Concentration Scheme for Partially Entangled Atomic States Through Detection of Cavity Decay

We propose a scheme for concentrating entanglement of partially entangled states for atoms trapped in the distant cavities. The scheme is based on adiabatic passage and photonic interference. It is robust against a number of practical noises such as the violation of the Lamb-Dicke condition, spontaneous emission and detection inefficiency.     

Two-Mode Excited Squeezed Vacuum State and Its Properties

In this paper, the two-mode excited squeezed vacuum state (TESVS) is studied by using the statistical method. By calculating the normalization of the TESVS, a new form of Jacobi polynomials and some new identities are obtained. The photon number distribution of the TESVS is given and it is a simple form of Jacobi polynomials. Using the entangled state representation of Wigner operator, the Wigner function of the TESVS is obtainded and the variations of the Wigner function with the parameters m, n, and r are discussed. Here from the phase space point of view the TESVS can be well interpreted and described.     

激光抽运极化原子束磁偏转铀浓缩方案

将激光抽运选择性极化原子束磁偏转方案用于铀同位素浓缩,考察了铀原子基态各子能级的磁偏转特性,提出了选择性光轴运极化的实验方案,讨论了可能得到的浓缩结果。     

HPLC法分析生物样品的前处理技术

介绍HPCL法分析生物样品的前处理技术。