9,920 research outputs found

    Radii and Binding Energies of Nuclei in the Alpha-Cluster Model

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    The alpha-cluster model is based on two assumptions that the proton-neutron pair interactions are responsible for adherence between alpha-clusters and that the NN-interaction in the alpha-clusters is isospin independent. It allows one to estimate the Coulomb energy and the short range inter-cluster bond energy in dependence on the number of clusters. The charge radii are calculated on the number of alpha-clusters too. Unlike the Weizsacker formula in this model the binding energies of alpha-clusters and excess neutrons are estimated separately. The calculated values are in a good agreement with the experimental data.Comment: Latex2e 2.09, 13 pages, 4 figure

    Masses and Radii of the Nuclei with N>=Z in an Alpha-Cluster Model

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    In the framework of a recently developed alpha-cluster model a nucleus is represented as a core (alpha-cluster liquid drop with dissolved excess neutron pairs in it) and a nuclear molecule on its surface. From analysis of experimental nuclear binding energies one can find the number of alpha-clusters in the molecule and calculate the nuclear charge radii. It was shown that for isotopes of one Z with growing A the number of alpha-clusters in the molecule decreases to three, which corresponds to the nucleus 12C for even Z and 15N for odd Z, and the specific density of the core binding energy \rho grows and reaches its saturation value. In this paper it is shown that the value \rho=2.55 MeV/fm^3 explains the particular number of excess neutrons in stable nuclei.Comment: 7 pages, 3 eps figures, submitted as a contribution to the Proceedings of the International Conference, Messina, Italy, October 5-9, 200

    Beliefs about medicines and self-reported medication adherence in Chinese patients with chronic diseases

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    Background For many chronic conditions, medication adherence is considered to be a crucial behaviour to achieve optimal outcomes. This thesis investigated beliefs about medicines and their associations with medication adherence in the Chinese patients. Methods Mixed methods were applied: 1) a meta-analysis summarised the correlations between specific beliefs about medicines and medication adherence in Chinese population; 2) semi-structured interviews explored Chinese patients’ cognitive representations about medicines (CRM) and links with medication-taking; 3) a ‘think-aloud’ task checked participants’ comprehension of a Chinese translation of the Beliefs about Medicines Questionnaire (BMQ); 4) an online survey assessed CRMs and medication adherence among Chinese patients and investigated determinants of low adherence using the logistic regression models; 5) ‘structural validity’ of an expanded version of the BMQ (e-BMQ) was explored using factor analysis. Results The main findings of this PhD work were: 1) Necessity beliefs (r=0.21, 95%CI: 0.07, 0.34) and concerns about medicines (r=-0.40, 95%CI: -0.48, -0.32) showed significant correlations with adherence in the Chinese population. 2) Five BMQ components (Necessity, Concern, Harm, Benefit, Overuse), perceived sensitivity to medicines (PSM), trust in medicines and beliefs about traditional Chinese medicines (TCM) were identified as themes to describe Chinese people’s CRMs that influenced medication taking. 3) The adjusted odds ratios of low adherence were significantly associated with Necessity (0.60, 95%CI: 0.46, 0.79), Harm (1.36, 95%CI: 1.02, 1.81) and PSM (1.27, 95%CI: 1.03, 1.55) among 742 Chinese patients with CHD, hypertension and T2DM. 4) Two additional factors of the e-BMQ, Trust in medicines (0.65, 95%CI: 0.42, 0.99) and beliefs about TCM (2.15, 95%CI: 1.02, 4.53), showed significant correlations with low adherence in diabetic patients and TCM users, respectively. Conclusion The expanded BMQ appears to be a validated measurement to assess beliefs about medicines in the Chinese population that gives insight into why low adherence occurred

    Binding energies of hydrogen-like impurities in a semiconductor in intense terahertz laser fields

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    A detailed theoretical study is presented for the influence of linearly polarised intense terahertz (THz) laser radiation on energy states of hydrogen-like impurities in semiconductors. The dependence of the binding energy for 1s and 2p states on intensity and frequency of the THz radiation has been examined.Comment: 14 pages, 4 figure

    Giant magnetoimpedance in crystalline Mumetal

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    We studied giant magnetoimpedance (GMI) effect in commercial crystalline Mumetal, with the emphasis to sample thickness dependence and annealing effects. By using appropriate heat treatment one can achieve GMI ratios as high as 310%, and field sensitivity of about 20%/Oe, which is comparable to the best GMI characteristics obtained for amorphous and nanocrystalline soft magnetic materials.Comment: 8 pages, 3 figure

    Differential quadrature method for space-fractional diffusion equations on 2D irregular domains

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    In mathematical physics, the space-fractional diffusion equations are of particular interest in the studies of physical phenomena modelled by L\'{e}vy processes, which are sometimes called super-diffusion equations. In this article, we develop the differential quadrature (DQ) methods for solving the 2D space-fractional diffusion equations on irregular domains. The methods in presence reduce the original equation into a set of ordinary differential equations (ODEs) by introducing valid DQ formulations to fractional directional derivatives based on the functional values at scattered nodal points on problem domain. The required weighted coefficients are calculated by using radial basis functions (RBFs) as trial functions, and the resultant ODEs are discretized by the Crank-Nicolson scheme. The main advantages of our methods lie in their flexibility and applicability to arbitrary domains. A series of illustrated examples are finally provided to support these points.Comment: 25 pages, 25 figures, 7 table
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