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21.
Wireless Personal Communications - In this paper, we propose novel equalization schemes for compensating the adverse effects caused by carrier frequency offsets (CFOs), timing errors and doubly...  相似文献   
22.
A new double-open-cubane core Cd(II)-O-Cu(II) bimetallic ligand mixed cluster of type [Cl2Cu4Cd2(NNO)6(NN)2(NO3)2].CH3CN was made available in EtOH/CH3CN solution. The 1-hydroxymethyl-3,5-dimethylpyrazole (NNOH) and 3,5-dimethylpyrazole (NNH) act as N,O-polydentate anion ligands in coordinating the Cu(II) and Cd(II) centers. The structure of the cluster in the solid state was proved by XRD study and confirmed in the liquid state by UV-vis analysis. The XRD result supported the construction of two octahedral and one square pyramid geometries types around the four Cu(II) centers and only octahedral geometry around Cd(II) two centers. Interestingly, NNOH ligand acts as a tetra-µ3-oxo and tri-µ2-oxo ligand; meanwhile, the N-N in NNH acts as classical bidentate anion/neutral ligands. The interactions in the lattice were detected experimentally by the XRD-packing result and computed via Hirschfeld surface analysis (HSA). The UV-vis., FT-IR and Energy Dispersive X-ray (EDX), supported the desired double-open cubane cluster composition. The oxidation potential of the desired cluster was evaluated using a 3,5-DTB-catechol 3,5-DTB-quinone as a catecholase model reaction.  相似文献   
23.
World Wide Web - The integration of Cloud computing and Internet of Things led to rapid growth in the edge computing field. This would not be achievable without combining the data centers’...  相似文献   
24.
The International Journal of Advanced Manufacturing Technology - The restoration of mandibular defects, especially large deformities is regarded as the most challenging surgical procedure owing to...  相似文献   
25.
Silicon - The silica-ortho-phenylenediamine(RHAOPDA) derived from Rice Husk Ash and o- phenylenediamine (OPDA) were synthesized. The prepared material was characterized by different techniques; N2-...  相似文献   
26.
Abstract

A novel modification for Green and Naghdi thermoelasticity model of type III is proposed in this article. This model is joined to other ones to treat a thermoelastic wave propagation problem in an annular disk. The closed-form solution of thermoelastic analysis of the annular disks has been presented to deduce temperature, radial displacement, dilatation and stresses. Results are illustrated and reported to compare the simple Green–Naghdi II and III and their modified single-, dual- and three-phase-lag models. Concluding remarks are added.  相似文献   
27.
Interactions of hexamethylenetetramine ligand in atom transfer radical polymerization initiated by activator generated by electron transfer were studied. Polymerization of methyl methacrylate was done using two-step experimental procedure in 2 L emulsion batch reactor at 50, 60, and 80°C. The selection of reactant ratios was quite challenging for a reactor of this size. Replicate runs were conducted for data reproducibility purpose. Gravimetry method and gel permeation chromatography were used to determine monomer conversion, Mn, and PDI of polymer samples. PMMA produced was also characterized by means of dynamic light scattering, Fourier-transform infrared spectroscopy and nuclear Magnetic Resonance spectroscopy. Results showed high monomer conversion up to 93% and Mn ranging 243–274 kg/mol with PDI from 1.45 to 1.60. Besides, combining HMTA with sodium dodecyl sulfate, an anionic surfactant, a well-controlled polymer with a lower Mn of 201 kg/mol and PDI of 1.56 was obtained in 3 hr reaction time.  相似文献   
28.
29.
Although additive manufacturing through melt extrusion has become increasingly popular as a route to design scaffolds with complex geometries the technique if often limited by the reduction in molecular weight and the viscoelastic response when degradable aliphatic polyesters of high molecular weight are used. Here we use a melt extruder and fused filament fabrication printer to produce a reliable nondegradative route for scaffold fabrication of medical grade copolymers of L-lactide, poly(ε-caprolactone-co-L-lactide), and poly(L-lactide-co-trimethylene carbonate). We show that degradation is avoided using filament extrusion and fused filament fabrication if the process parameters are deliberately chosen based upon the rheological behavior, mechanical properties, and polymer composition. Structural, mechanical, and thermal properties were assessed throughout the process to obtain comprehension of the relationship between the rheological properties and the behavior of the medical grade copolymers in the extruder and printer. Scaffolds with a controlled architecture were achieved using high-molecular-weight polyesters exhibiting a large range in the elastic response causing negligible degradation of the polymers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48550.  相似文献   
30.
Aluminum dross produced from aluminum industry was used to fabricate Al2O3/Al porous composites. The dross was milled for 20?h to obtain nano powder. The milled material was examined by TEM and XRD. Graphene (up to 4?wt%) was mixed with the dross and utilized to reinforce sintered composites. The milled powders were compacted then fired at various temperatures up to 700?°C. Physical properties in terms of bulk density and apparent porosity for sintered composites were tested using Archimedes method. SEM attached by energy dispersive spectrometer (EDS) was used to inspect microstructure and elemental analysis of sintered composites. Microhardness and compressive strength were also measured. Ultrasonic nondestructive technique was utilized to examine the elastic moduli. Electrical conductivity of sintered composite was also studied. During milling up to 20?h, Al2O3/Al core-shell was in-situ formed with size of 65.9 and 23.8?nm, respectively. The apparent porosity of sintered composites was improved with rising graphene percent while it decreased with increasing sintering temperature. Increasing of graphene mass percent and firing temperature led to remarkable increase in all mechanical properties and electrical conductivity. The maximum compressive strength, hardness, elastic modulus and electrical conductivity were 200?MPa, 1200?MPa, 215?GPa and 1.42?×?10?5 S/m, respectively, obtained for composite sintered at 700?°C having 4?wt% graphene.  相似文献   
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