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A. Malki J. P. Coffin G. Guillaume F. Jundt K. Krishan F. Rami P. Wagner P. Fintz M. Zahar M. Gonin B. Heusch M. Ohta B. Rastegar D. Rebreyend F. Merchez J. Mistretta S. Kox 《Zeitschrift für Physik A Hadrons and Nuclei》1991,339(2):283-292
In an attempt to separate preequilibrium and thermalised emissions of light particles in low impact parameter heavy-ion collisions, the40Ar+24Mg reaction has been studied at 27.5 MeV/nucleon. Exclusive measurements have permitted us to examine, in some detail, heavy fragments and charged particles (p, d, t,-particle). The fragments recognized as evaporation residues have been selected and, due to inverse kinematic conditions, the related preequilibrium and statistical emissions of light particles resulting from incomplete fusion reaction appear to be distinguishable to a fair extent. This separation is fully supported by Monte Carlo calculations. Some experimental characteristics of the light particles have been examined and compared to the predictions of dynamical calculations. These calculations, associating a preequilibrium (interpreted as prompt emitted particles) model with a statistical-decay model, follow the evolution of the collision from the point of contact between the projectile and the target to the final evaporation-residue formation on an event by event basis. The predictions of these calculations have been compared to experimental data and satisfactory agreement is achieved for fragment-mass distribution, proton-energy spectra, and proton-angular distribution. 相似文献
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Begaa Samir Messaoudi Mohammed Ouanezar Abdelkader Hamidatou Lylia Malki Abderrahim 《Journal of Radioanalytical and Nuclear Chemistry》2018,317(2):1107-1112
Journal of Radioanalytical and Nuclear Chemistry - The objectives of this research were to study the elemental concentrations of Mentha spicata L., using a sensitive nuclear analytical technique... 相似文献
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M. Zahar A. Malki M. Bozin P. Wagner F. Rami J. P. Coffin G. Guillaume F. Jundt P. Fintz B. Rastegar D. Rebreyend F. Merchez J. Mistretta S. Kox 《Zeitschrift für Physik A Hadrons and Nuclei》1991,339(4):465-473
Protons, deuterons, tritons,α-particles and Li have been studied in coincidence with evaporation residues produced at low impact parameter for the40Ar(1100 MeV)+13C reaction. Experimental characteristics of the light particle — heavy residue correlations, and among them an effect of left-right asymmetry, are analyzed and discussed in some detail on the basis of Monte Carlo simulations. This reaction appears to be governed by an incomplete fusion process. Due to transverse emission of preequilibrium particles, the compound nuclei associated with light-particle-evaporation-residue coincidence events recoil at a non-zero degree lab. angle with some dispersion around this direction. When these effects are introduced into statistical decay calculations, it is then possible to reproduce various experimental results and to understand features like the asymmetry effect. Discrimination of light particles of preequilibrium and of evaporative origin appears possible. 相似文献
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A. Grandjean M. Malki V. Montouillout F. Debruycker D. Massiot 《Journal of Non》2008,354(15-16):1664-1670
A large number of compositions within the SiO2–NaO2–B2O3 (SNB) ternary glass system were investigated by various complementary techniques. Impedance spectroscopy was used to determine the parameters related to sodium ion diffusion in the glass structure; high-field boron NMR measurements on a series of samples identified and quantified the boron coordination as a function of the composition; exhaustive DTA measurements gave the glass transition temperature for all the compositions studied. Based on these results we demonstrate that the activation energy of sodium ion diffusion is closely related to the boron coordination number and involves two types of structural motifs: one corresponding to the sodium associated to non-bridging oxygen atoms, and the other to sodium compensating BIV motif. We also show that simple DTA measurements of the glass transition temperature can be used to define structural domains within this ternary composition range. 相似文献
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The occurrence of discrete Eu(II) and Eu(III) valence states in Eu14Cl33, is consistently demonstrated from X-ray diffraction data, Mössbauer effect and magnetic susceptibility measurements. The ratio of the mean square amplitudes of lattice vibrations of the Eu(II) and Eu(III) ions deduced from Mössbauer data is in good agreement with the one obtained from X-ray Debye-Waller factors. 相似文献
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Ponnambalam Rameshwaran Pamela Naden Catherine A.M.E. Wilson Rami Malki Deepak R. Shukla Koji Shiono 《Applied Mathematical Modelling》2013,37(20-21):8652-8672
This paper presents a study in the inter-comparison and validation of three-dimensional computational fluid dynamics codes which are currently used in river engineering. Finite volume codes PHOENICS, FLUENT and SSIIM; and finite element code TELEMAC3D are considered in this study. The work has been carried out by competent hydraulic modellers who are users of the codes and not involved in their development. This paper is therefore written from the perspective of independent practitioners of the techniques. In all codes, the flow calculations are performed by solving the three-dimensional continuity and Reynolds-averaged Navier–Stokes equations with the k–ε turbulence model. The application of each code was carried out independently and this led to slightly different, but nonetheless valid, models. This is particularly seen in the different boundary conditions which have been applied and which arise in part from differences in the modelling approaches and methodology adopted by the different research groups and in part from the different assumptions and formulations implemented in the different codes. Similar finite volume meshes are used in the simulations with PHOENICS, FLUENT and SSIIM while in TELEMAC3D, a triangular finite element mesh is used. The ASME Journal of Fluids Engineering editorial policy is taken as a minimum framework for the control of numerical accuracy. In all cases, grid convergence is demonstrated and conventional criteria, such as Y+, are satisfied. A rigorous inter-comparison of the codes is performed using large-scale experimental data from the UK Flood Channel Facility for a two-stage meandering channel. This example data set shows complex hydraulic behaviour without the additional complications found in natural rivers. Standardised methods are used to compare each model with the available experimental data. Results are shown for the streamwise and transverse velocities, secondary flow, turbulent kinetic energy, bed shear stress and free surface elevation. They demonstrate that the models produce similar results overall, although there are some differences in the predicted flow field and greater differences in turbulent kinetic energy and bed shear stress. This study is seen as an essential first step in the inter-comparison of some of the computational fluid dynamics codes used in the field of river engineering. 相似文献
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We report what is to our knowledge the first characterization at high temperatures of long-period fiber gratings written in Ge-free air-silica microstructure fiber. The gratings written with the electric-arc technique suffer a low shift of the resonance wavelengths when the temperature is increased from 20 degrees C to 1200 degrees C. This shift is studied and compared with that of a long-period fiber grating written in a standard single-mode fiber by the same technique. Good thermal stability of the grating and of the fiber after annealing at 1200 degrees C for 1 h is demonstrated. 相似文献
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Ashraf N. Abdalla Waleed H. Malki Amal Qattan Imran Shahid Mohammad Akbar Hossain Muhammad Ahmed 《Molecules (Basel, Switzerland)》2021,26(2)
Colorectal cancer (CRC) remains one of the main causes of death worldwide and in Saudi Arabia. The toxicity and the development of resistance against 5 fluorouracil 5FU pose increasing therapeutic difficulties, which necessitates the development of personalized drugs and drug combinations. Objectives: First, to determine the most important kinases and kinase pathways, and the amount of ABC transporters and KRAS in samples taken from Saudi CRC patients. Second, to investigate the chemosensitizing effect of LY294002 and HAA2020 and their combinations with 5FU on HT29, HT29-5FU, HCT116, and HCT116-5FU CRC cells, their effect on the three ABC transporters, cell cycle, and apoptosis, in light of the important kinase pathways resulting from the first part of this study. Methods: The PamChip® peptide micro-array profiling was used to determine the level of kinase and targets in the Saudi CRC samples. Next, RT-PCR, MTT cytotoxicity, Western blotting, perturbation of cell cycle, annexin V, and immunofluorescence assays were used to investigate the effect on CRC, MRC5, and HUVEC cells. Results: The kinase activity profiling highlighted the importance of the PI3K/AKT, MAPK, and the growth factors pathways in the Saudi CRC samples. PIK3CA was the most overexpressed, and it was associated with increased level of mutated KRAS and the three ABC transporters, especially ABCC1 in the Saudi samples. Next, combining HAA2020 with 5FU exhibited the best synergistic and resistance-reversal effect in the four CRC cells, and the highest selectivity indices compared to MRC5 and HUVEC normal cells. Additionally, HAA2020 with 5FU exerted significant inhibition of ABCC1 in the four CRC cells, and inhibition of PIK3CA/AKT/MAPK7/ERK in HT29 and HT29-5FU cells. The combination also inhibited EGFR, increased the preG1/S cell cycle phases, apoptosis, and caspase 8 in HT29 cells, while it increased the G1 phase, p21/p27, and apoptosis in HT29-5FU cells. Conclusion: We have combined the PamChip kinase profiling of Saudi CRC samples with in vitro drug combination studies in four CRC cells, highlighting the importance of targeting PIK3CA and ABCC1 for Saudi CRC patients, especially given that the overexpression of PIK3CA mutations was previously linked with the lack of activity for the anti-EGFRs as first line treatment for CRC patients. The combination of HAA2020 and 5FU has selectively sensitized the four CRC cells to 5FU and could be further studied. 相似文献