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排序方式: 共有194条查询结果,搜索用时 15 毫秒
51.
Dr. Abderrahmane Semmeq Dr. Michael Badawi Prof. Abdellatif Hasnaoui Prof. Said Ouaskit Dr. Antonio Monari 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(49):11340-11344
The effect of ionizing radiation on DNA constituents is a widely studied fundamental process using experimental and computational techniques. In particular, radiation effects on nucleobases are usually tackled by mass spectrometry in which the nucleobase is embedded in a water nanodroplet. Here, we present a multiscale theoretical study revealing the effects and the dynamics of water droplets towards neutral and ionized thymine. In particular, by using both hybrid quantum mechanics/molecular mechanics and full ab initio molecular dynamics, we reveal an unexpected proton transfer from thymine cation to a nearby water molecule. This leads to the formation of a neutral radical thymine and a Zundel structure, while the hydrated proton localizes at the interface between the deprotonated thymine and the water droplet. This observation opens entirely novel perspectives concerning the reactivity and further fragmentation of ionized nucleobases. 相似文献
52.
Awad A. H. Abdel-Ghany Ahmed W. Abd El-Wahab Ayman A. El-Gamasy Ramadan Abdellatif Mohamed Hazem 《Journal of Thermal Analysis and Calorimetry》2020,140(6):2615-2623
Journal of Thermal Analysis and Calorimetry - The purpose of this work is to investigate the opportunity of re-using M&G wastes to get novel PP composites. Recycling of marble and granite... 相似文献
53.
In this Note we establish a Hölder stability estimate for an inverse pointwise source elliptic problem. 相似文献
54.
The regioselective synthesis of two new acetylenic compounds, sterehirsutinal ( 1 ) and sterehirsutinol ( 2 ), isolated recently from culture medium of the fungus Stereum hirsutum, is reported. 相似文献
55.
Electrochemical Characterization of Carbon Solidlike Paste Electrode Assembled Using Different Carbon Nanoparticles 下载免费PDF全文
Seif Islam Rabie Malha Abdellatif Ait Lahcen Fabiana Arduini Ali Ourari Aziz Amine 《Electroanalysis》2016,28(5):1044-1051
Solid like carbon paste electrodes (SCPEs) are built using different carbon materials namely carbon black N110, N220, N375, N772 and acetylene black. The electrochemical behavior of these electrodes and the influence of carbon black/paraffin ratio were studied and the results were discussed and compared to other electrodes prepared with graphite, mesoporous carbon and nanopowder carbon. Cyclic voltammetry, amperometry and electrochemical impedance spectroscopy were employed for their electrochemical and analytical characterizations. Amperometric measurements using N110, N220, N375 SCPEs with solid paraffin, showed a linear response of benzoquinone concentration with a detection limit of 75, 32 and 171 nM respectively. 相似文献
56.
Abdellatif Ghendir Aoun 《应用数学年刊》2017,33(4):340-352
In this paper, we study a fractional differential equation $$^{c}D^{\alpha}_{0^{+}}u(t)+f(t,u(t))=0,\quad t\in(0, +\infty)$$ satisfying the boundary conditions:
$$u^{\prime}(0)=0,\quad \lim_{t\rightarrow +\infty}\,^{c}D^{\alpha-1}_{0^{+}}u(t)=g(u),$$ where $1<\alpha\leqslant2$, $^{c}D^{\alpha}_{0^{+}}$ is the standard Caputo fractional derivative of order $\alpha$. The main tools used in the paper is contraction principle in the Banach space and the fixed point theorem due to
D. O''Regan. Some the compactness criterion and existence of solutions are established. 相似文献
57.
Abdellatif Agouzal 《计算数学(英文版)》2000,18(6):639-644
1. IlltroductionThe finite element approximation of the convection--diffusin equations has been investigated using several different approaches (see e.g. [3] [4] and the references therein).Previous analysis in primal formulation of these problems was done for two types ofapproximation schemes: one which produces a continuous piecewise polynomial approximation and one which produces a piecewise polynomial approximation which arecontinuous for certain number of moments accross interelement edge… 相似文献
58.
59.
Abdellatif Mamanou Fethi Khelfaoui Kamel Edinne Aiadi 《Optical and Quantum Electronics》2014,46(1):235-245
In this paper, a number of polymeric waveguide structures have been analyzed by using two distinct techniques which are: effective index method (EIM) and numerical simulation based on finite difference method (FDM). The main aim of this investigation is the calculation of effective indexes (EI) of the following structures: rib, ridge and buried channel waveguides at telecom wavelength $\lambda =1.55\,\upmu \hbox {m}$ for different dimensions of waveguide cores varying from 1.5–4 $\upmu \hbox {m}$ . Moreover, other optical propagation characteristics such as: confinement factor, normalized and propagation constant have been studied in TE polarisation. Otherwise the effect of the structure parameters and dimensions on the dispersion characteristics has been investigated. On the other hand, the optical field distribution has been computed using commercial software named OlympIOs. The polymers applied in the design of waveguide structures are the PVCi (n = 1,562 $\lambda = {1.55}\,\upmu $ m) used as core layer and the PMATRIFE (n = 1,409 $\lambda = 1.55\,\upmu $ m) used as substrate or cladding layer. The results obtained using EIM and simulation based on FDM show that effective index and field confinement factor of TE fundamental mode increase monotonously with the increasing dimension of core. The obtained results are in good agreement with published data based on other numerical methods. 相似文献
60.
A. Abada K. Bouakaz N. Daira-Aifa 《The European Physical Journal C - Particles and Fields》2001,18(4):765-777
We determine the analytic expression of the damping rates for very soft moving quarks in an expansion to second order in
powers of their momentum in the context of QCD at high temperature. The calculation is performed using the hard-thermal-loop-summed
perturbation scheme. We describe the range of validity of the expansion and make a comparison with other calculations, particularly
those using a magnetic mass as a shield from infrared sensitivity. We discuss the possible occurrence of infrared divergences
in our results and argue that they are due to magnetic sensitivity.
Received: 1 September 2000 / Published online: 5 February 2001 相似文献