Mn55(p,p′γ)Mn55 reaction low proton energies

Angular distributions of gamma rays following the inelastic scattering of protons from Mn⁵⁵ have been measured at proton energies below 2.50 MeV. The mixture multipole orders for the transition 983→126 keV and 1,530→0 in Mn⁵⁵ have been obtained.     

X-ray detected magnetic resonance at the Fe K-edge in YIG: Forced precession of magnetically polarized orbital components

X-ray detected magnetic resonance (XDMR) has been measured for the first time on exciting the Fe K-edge in a high-quality yttrium iron garnet film epitaxially grown on a gadolinium gallium garnet substrate. This challenging experiment required resonant pumping of yttrium iron garnet at high microwave power, i.e., in the foldover regime. X-ray magnetic circular dichroism (XMCD) was used to probe the change in the longitudinal component of the magnetization M _Z induced by the precession of magnetic moments located at the iron sites. Since XMCD at the Fe K-edge refers mostly to the equilibrium contribution of magnetically polarized 4p orbital components, XDMR at the Fe K-edge should reflect the precessional dynamics of the latter orbital moments. From the measured precession angle, we show that there is no dynamical quenching of the polarized orbital components at the iron sites in yttrium iron garnet.     

Hypericin and Pseudohypericin. Purity Criteria and Quantitative Determination in Extracts of Saint John’s Wort (Hypericum perforatum)

Summary. Hypericin and pseudohypericin in extracts of St. Johns Wort (Hypericum perforatum) are assayed using UV-Vis, measuring the absorbance at 588nm of a methanolic solution of the compounds. The value of the absorption coefficient is difficult to define insofar as none of the routine purity criteria can be applied to these two compounds. Analysis of the entire UV-Vis spectrum from 220 to 740nm would seem to be a reliable way of comparing different samples. A UV-Vis spectrum was recorded for each of the compounds using a Photodiode array detection system. A more accurate way of determining the levels of hypericin and pseudohypericin in extracts of St. Johns Wort using these reference spectra is described.     

Non-linear actuation of cantilevers using giant magnetostrictive thin films

In the present paper, we report the first results concerning a centimetre cantilever driven through non-linear effects in thin magnetostrictive films. Bimorph centimetre beams (24 mm x 5 mm) were designed using 160 microns thick glass and 0.4 micron thick multilayer TbFe/Fe films deposited via RF sputtering, using several sputtering conditions. Dynamic magneto-elastic excitations were studied experimentally on the few eigenresonance modes of the cantilevers. Sub-harmonic excitation at half or one-third of the frequency of an eigenresonance mode has been achieved near the spin reorientation transition and the efficiency is as good as for eigenfrequency excitation. Specific magnetic properties of the samples led to a model of the thermodynamic potentials and behaviour of the excited resonator.     

Two-dimensional problem of a two-temperature generalized thermoelastic half-space subjected to ramp-type heating

In this work, we will consider a half-space filled with an elastic material, which has constant elastic parameters. The governing equations are taken in the context of the theory of two-temperature generalized thermoelasticity. A linear temperature ramping function is used to more realistically model thermal loading of the half-space surface. The medium is assumed initially quiescent. Laplace and Fourier transform techniques are used to obtain the general solution for any set of boundary conditions. The general solution obtained is applied to a specific problem of a half-space subjected to ramp-type heating. The inverse Fourier transforms are obtained analytically while the inverse Laplace transforms are computed numerically using a method based on Fourier expansion techniques. Some comparisons have been shown in figures to estimate the effect of the ramping parameter of heating.     

Identities of arithmetic type between values of the theta function associated to a lattice in ℝ d and its derivatives

In this paper, we introduce a notion of similarly self dual lattice in a d-dimensional Euclidean space and a classical Jacobi theta function is associated to such a lattice. We establish identities of arithmetic type between values of this theta function and its successive derivatives. This work can be related to the spectral theory of the Landau operators.      

A second-order boundary value problem with impulsive effects on an unbounded domain

We study a second-order nonlinear differential equation on an unbounded domain with solutions subject to impulsive conditions and the Sturm–Liouville type boundary conditions. The existence results are obtained via applications of Krasnosel’ski?’s fixed point theorem for the sum of a completely continuous operator and a contraction.     

同位素内标超高效液相色谱-串联质谱法检测大鼠血清中丙烯酰胺和环氧丙酰胺

建立了检测大鼠血清中丙烯酰胺和环氧丙酰胺的超高效液相色谱-串联质谱法(UPLC-MS/MS).血清样品中加入乙腈沉淀蛋白质,超高速离心取上清液,离心浓缩后,采用ACQUITY UPLC T3 C18色谱柱(50 mm×2.1 mm, 1.7 μm),以0.1%甲酸溶液和甲醇为流动相进行梯度洗脱,经UPLC分离,电喷雾离子化四级杆串联质谱以正离子多反应监测方式(MRM)检测,用同位素内标法定量.丙烯酰胺和环氧丙酰胺在0.5～20.0 mg/L浓度范围内线性良好,相关系数r均大于0.999;检出限均为0.1 mg/L;在3个浓度水平(2.0, 8.0, 和15.0 mg/L)进行添加实验,样品的加标回收率分别为98.0%～108.3%和99.6%～106.7%;日内精密度(RSD)为0.54%～5.8%和1.1%～5.8%;每个样品测试时间仅为6 min.本方法测定大鼠血清中的丙烯酰胺和环氧丙酰胺操作简单快速, 重现性好, 灵敏度高.