9,957 research outputs found
Radii and Binding Energies of Nuclei in the Alpha-Cluster Model
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
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
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
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
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
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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