Adsorption and desorption phenomena on thermally annealed multi-walled carbon nanotubes by XANES study

The multi-walled carbon nanotubes(MWCNTs) studied in this work were synthesized by the catalytic chemical vapor deposition(CCVD) process, and were thermally annealed by the hot filament plasma enhanced(HF PE) method at 550℃ for two hours.The x-ray absorption near edge structure(XANES) technique was used to investigate the adsorption and desorption phenomena of the MWCNTs at normal and grazing incidence angles.The adsorbates were found to have different sensitivities to the thermal annealing.The geometry of the incident beam consistently gave information about the adsorption and desorption phenomena.In addition, the adsorption of non-intrinsic potassium quantitatively affected the intrinsic adsorbates and contributed to increase the conductivity of the MWCNTs.The desorption of potassium was almost 70% greater after the thermal annealing.The potassium non-intrinsic adsorbates are from a physisorption mechanism whereas the intrinsic adsorbates result from chemisorption.

Crustal thickness beneath Atlas region from gravity,topographic,sediment and seismic data

The Atlas region in northwest Africa is characterized by the Quaternary volcanism and elevated topography with past complex tectonic mitigation between the African and European plates.Geodynamics of this atypical region has left indubitably imprints in crustal architectonics,mainly regarding the crustal thickness as well as the crustal density structure.The knowledge of crustal thickness variations is of a significant interest,since it provides a crucial constraint to geodynamic and geophysical modelling of this region.In this study,we use gravity,topographic,bathymetric and sediment data together with results of seismic surveys to image the Moho topography beneath the Atlas region.The Bouguer gravity anomalies used for a gravimetric Moho recovery are obtained from the free-air gravity anomalies after subtracting the gravitational contributions of topography,bathymetry and sediments.The regional gravimetric Moho inversion constrained on seismic data is carried out by applying a regularized inversion technique based on Gauss-Newton’s formulation of improved Bott’s method,while adopting Earth’s spherical approximation.The numerical result reveals relatively significant Moho depth variations in the Moroccan Atlas,with minima of approximately 24 km along continental margins of the Mediterranean Sea and maxima exceeding 51 km beneath the Rif Cordillera.The Moho depth beneath the West African Craton varies from 32 km in its southern margin to 45 km beneath the Middle Atlas.The Tell Atlas is characterized by the shallow Moho depth of approximately 22 km and further deepening to 42 km towards the northern edge of the Aures Mountains.Our findings indicate a limited tectonic shortening of the High Atlas with the crustal thickness mostly within 36-42 km.Topographic discrepancies between the Rif Cordillera and the Atlas Mountains suggest that the hypothesis of isostatic compensation cannot be fully established.

On the Conversion of High-Frequency Soliton Solutions to a （1＋1）-Dimensional Nonlinear Partial Differential Evolution Equation

From the dynamical equation of barotropic relaxing media beneath pressure perturbations, and using the reductive perturbative analysis, we investigate the soliton structure of a （1＋1）-dimensional nonlinear partial differential evolution （NLPDE） equation δy（δη ＋ uδy ＋ （u^2/2）δy）u ＋ auy ＋ u = 0, describing high-frequency regime of perturbations. Thus, by means of Hirota＇s bilinearization method, three typical solutions depending strongly upon a characteristic dissipation parameter are unearthed.

Isobavachalcone:An Overview

Isobavachalcone （IBC） or （E）-l-[2,4-dihydroxy-3-（3-methyl-2-butenyl）-phenyl]-3-（4- hydroxyphenyl）-2-propen-1-one or （E）-4,2＇,4＇-trihydroxy-3＇-prenylchalcone; 2＇,4,4＇-trihydroxy-3＇-prenyl-trans- chalcone, is a prenylated chalcone of the class flavonoid, firstly isolated from Psoralea corylifolia in 1968. IBC is known to possess a wide spectrum of biological activities, antibacterial, antifungal, anticancer, anti-reverse transcriptase, antitubercular and antioxidant. The compound was isolated from plant families, mostly Moraceae and Fabaceae. This review brings out together the knowledge on IBC, and can serve as the start point for future research and valorization accomplishments.