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91.
The recent development of a myriad of heterogeneous wireless technologies that share the same core IP is driving the mobility as a key issue for the future wireless Internet. One of the critical challenges is to support uninterrupted and seamless multimedia services while on the move. This article focuses on mobility management in the future Internet regarding a solution proposed in the Autonomic Internet (AutoI) project. Our mobility management solution aims at enhancing user mobility experience and enabling adaptability and context awareness in the future wireless Internet. This is achieved through the use of more adequate information exploited by a utility-based mobility decision approach as well as a hysteresis margin to preserve decision stability. The proposed solution is discussed and experimental validations are performed to evaluate its impact on real-world scenarios. The proposed solution has been demonstrated to be effective in providing seamless user experience even with frequent handovers. Further, the use of the hysteresis-based mobility decision solution has been effective to reduce the number of handovers, without precluding the quality of connections. 相似文献
92.
93.
Sergey A. Krasnikov Sergey I. Bozhko Kevin Radican Olaf Lübben Barry E. Murphy Sundar-Raja Vadapoo Han-Chun Wu Mohamed Abid Valery N. Semenov lgor V. Shvets 《Nano Research》2011,4(2):194-203
The growth and ordering of C60 molecules on the WO2/W(110) surface have been studied by low-temperature scanning tunnelling microscopy and spectroscopy (STM and STS), low-energy
electron diffraction (LEED), and density functional theory (DFT) calculations. The results indicate the growth of a well-ordered
C60 layer on the WO2/W(110) surface in which the molecules form a close-packed hexagonal structure with a unit cell parameter equal to 0.95 nm.
The nucleation of the C60 layer starts at the substrate’s inner step edges. Low-temperature STM of C60 molecules performed at 78 K demonstrates well-resolved molecular orbitals within individual molecules. In the C60 monolayer on the WO2/W(110) surface, the molecules are aligned in one direction due to intermolecular interaction, as shown by the ordered molecular
orbitals of individual C60. STS data obtained from the C60 monolayer on the WO2/W(110) surface are in good agreement with DFT calculations. 相似文献
94.
Hichem Mallek Corinne Jegat Nathalie Mignard Majdi Abid Souhir Abid Mohamed Taha 《应用聚合物科学杂志》2013,129(3):954-964
Poly(ε‐caprolactone) (PCL)‐based thermoreversible networks with self‐healing properties were prepared through Diels–Alder (DA) and retro‐DA reactions. Bis‐ or Tris‐maleimide compounds and a series of copolymer(caprolactone‐diene) PCLXFY (X: degree of polymerization and Y: furan‐average functionality) with Y between 2.4 and 4.9 were used. The successive sequences of formation and dissociation of polycaprolactone networks via DA and retro‐DA reactions were observed repeatedly by dynamic mechanical analyses (DMA) and their gel‐temperatures determined. The cross‐linking densities, thermal properties, and thermal reversibility of the PCLXFY/multimaleimide polymers have been modulated by the structure and functionalities of the used diene and dienophile moieties. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
95.
Abdul LATIF Xiangjun XIN Aftab HUSSAIN Liu BO Yousaf KHAN Ashiq HUSSAIN Abid MUNIR 《中国光电子学前沿》2012,(3)
We proposed an arrayed waveguide granting (AWG) based 10 Gbps full duplex wavelength division multiplexing passive optical network (WDM-PON) utilizing a retum-to-zero differential phase shift keying (R... 相似文献
96.
Aamir D. Abid 《Combustion and Flame》2009,156(10):1862-17251
A burner-stabilized, stagnation flame technique is introduced. In this technique, a previously developed sampling probe is combined with a water-cooled circular plate such that the combination simultaneously acts as a flow stagnation surface and soot sample probe for mobility particle sizing. The technique allows for a rigorous definition of the boundary conditions of the flame with probe intrusion and enables less ambiguous comparison between experiment and model. Tests on a 16.3% ethylene-23.7% oxygen-argon flame at atmospheric pressure show that with the boundary temperatures of the burner and stagnation surfaces accurately determined, the entire temperature field may be reproduced by pseudo one-dimensional stagnation reacting flow simulation using these temperature values as the input boundary conditions. Soot particle size distribution functions were determined for the burner-stabilized, stagnation flame at several burner-to-stagnation surface separations. It was found that the tubular probe developed earlier perturbs the flow and flame temperature in a way which is better described by a one-dimensional stagnation reacting flow than by a burner-stabilized flame free of probe intrusion. 相似文献
97.
The synthesis of N‐heteroaryl(trifluoromethyl)hydroxyalkanoic acid esters by solid acid‐catalyzed Friedel–Crafts hydroxyalkylation of indoles and pyrroles with ethyl 3,3,3‐trifluoropyruvate and ethyl 4,4,4‐trifluoroacetoacetate is described. The inexpensive and readily available K‐10 montmorillonite is found to be an efficient catalyst for the synthesis of a wide variety of trifluoromethylated indol‐3‐yl‐ and pyrrol‐2‐yl‐hydroxypropionic and ‐butanoic acid esters. Using a series of substituted indoles and pyrroles the corresponding products were isolated in excellent yield (up to 98%) and 100% selectivity under mild experimental conditions, during very short reaction times. Beyond these, the ease of product isolation, catalyst stability and handling make this process an attractive, environmentally benign alternative for the synthesis of the target compounds. 相似文献
98.
The goal of this study was to determine the effect of putrescine, added to the culture medium, on the in vitro development of stenospermic grape (Vitis vinifera L) embryos. The cross breedings of Perlón x G.C88552 and Perlón x Argentina were used. 0 (control), 2 and 4 mM of putrescine were added to the immature seed’s culture medium. In Perlón x Argentina, 2mM of putrescine statistically increased the percentage of total embryos, direct germination, polyembryos and normal plants. In Perlón x G.C88552, only 2 mM of putrescine increased all the variables considered, eventually tripling the percentage of normal plants obtained. The results suggest that the endogenous concentration of putrescine may be a growth limiting factor. Adding putrescine to the culture medium of immature grape seeds is a legitimate resource to significantly increase the results of this technique. 相似文献
99.
Massimiliano S. Tagliamonte Nabil Abid Stefano Borocci Elisa Sangiovanni David A. Ostrov Sergei L. Kosakovsky Pond Marco Salemi Giovanni Chillemi Carla Mavian 《International journal of molecular sciences》2021,22(1)
Our evolutionary and structural analyses revealed that the severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2) spike gene is a complex mosaic resulting from several recombination events. Additionally, the fixation of variants has mainly been driven by purifying selection, suggesting the presence of conserved structural features. Our dynamic simulations identified two main long-range covariant dynamic movements of the novel glycoprotein, and showed that, as a result of the evolutionary duality, they are preserved. The first movement involves the receptor binding domain with the N-terminal domain and the C-terminal domain 2 and is maintained across human, bat and pangolin coronaviruses. The second is a complex network of long-range dynamics specific to SARS-CoV-2 involving the novel PRRA and the conserved KR*SF cleavage sites, as well as conserved segments in C-terminal domain 3. These movements, essential for host cell binding, are maintained by hinges conserved across human, bat, and pangolin coronaviruses glycoproteins. The hinges, located around Threonine 333 and Proline 527 within the N-terminal domain and C-terminal domain 2, represent candidate targets for the future development of novel pan-coronavirus inhibitors. In summary, we show that while recombination created a new configuration that increased the covariant dynamic movements of the SARS-CoV-2 glycoprotein, negative selection preserved its inter-domain structure throughout evolution in different hosts and inter-species transmissions. 相似文献
100.