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81.
82.
Karim Bouchmella Sylvain G. Dutremez Dr. Christian Guérin Prof. Dr. Jean‐Christophe Longato Françoise Dahan Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(8):2528-2536
Hydrolyses of HC?CSO3SiMe3 ( 1 ) and CH3C?CSO3SiMe3 ( 2 ) lead to the formation of acetylenic sulfonic acids HC?CSO3H?2.33 H2O ( 3 ) and CH3C?CSO3H?1.88 H2O ( 4 ). These acids were reacted with guanidinium carbonate to yield [+C(NH2)3][HC?CSO3?] ( 5 ) and [+C(NH2)3][CH3C?CSO3?] ( 6 ). Compounds 1 – 6 were characterized by spectroscopic methods, and the X‐ray crystal structures of the guanidinium salts were determined. The X‐ray results of 5 show that the guanidinium cations and organosulfonate anions associate into 1D ribbons through ${{\rm R}{{2\hfill \atop 2\hfill}}}$ (8) dimer interactions, whereas association of these ions in 6 is achieved through ${{\rm R}{{2\hfill \atop 2\hfill}}}$ (8) and ${{\rm R}{{1\hfill \atop 2\hfill}}}$ (6) interactions. The ribbons in 5 associate into 2D sheets through ${{\rm R}{{2\hfill \atop 2\hfill}}}$ (8) dimer interactions and ${{\rm R}{{3\hfill \atop 6\hfill}}}$ (12) rings, whereas those in 6 are connected through ${{\rm R}{{1\hfill \atop 2\hfill}}}$ (6) and ${{\rm R}{{2\hfill \atop 2\hfill}}}$ (8) dimer interactions and ${{\rm R}{{4\hfill \atop 6\hfill}}}$ (14) rings. Compound 6 exhibits a single‐layer stacking motif similar to that found in guanidinium alkane‐ and arenesulfonates, that is, the alkynyl groups alternate orientation from one ribbon to the next. The stacking motif in 5 is also single‐layer, but due to interlayer hydrogen bonding between sulfonate anions, the alkynyl groups of each sheet all point to the same side of the sheet. 相似文献
83.
Electrospinning fabrication and characterization of poly(vinyl alcohol)/montmorillonite/silver hybrid nanofibers for antibacterial applications 总被引:1,自引:0,他引:1
Jae Hyeung Park Mohammad Rezaul Karim In Kyo Kim In Woo Cheong Jong Won Kim Do Gyu Bae Jin Won Cho Jeong Hyun Yeum 《Colloid and polymer science》2010,288(1):115-121
Poly(vinyl alcohol) (PVA)/montmorillonite clay (MMT)/silver (Ag) nanoparticles have been electrospun for fabricating PVA/MMT/Ag
nanofiber in aqueous solutions. Since PVA is a water-soluble and biocompatible polymer, it is one of the best materials for
preparation of antibacterial nanofiber. MMT has been used as an inorganic filler to enhance properties of homopolymeric nanofiber.
The PVA/MMT/Ag nanofiber diameter increases with increasing contents of MMT clay and Ag nanoparticles. In preservation test,
the PVA/MMT/Ag nanofiber confirms an excellent antibacterial performance, elucidating for practical uses as a new preservative.
Moreover, the PVA/MMT/Ag nanofiber shows improved thermal properties. 相似文献
84.
Asadpour-Zeynali K Ghavami R Esfandiari R Soheili-Azad P 《Journal of AOAC International》2010,93(6):1995-2001
A novel net analyte signal standard addition method (NASSAM) was used for simultaneous determination of the drugs anthazoline and naphazoline. The NASSAM can be applied for determination of analytes in the presence of known interferents. The proposed method is used to eliminate the calibration and prediction steps of multivariate calibration methods; the determination is carried out in a single step for each analyte. The accuracy of the predictions against the H-point standard addition method is independent of the shape of the analyte and interferent spectra. The net analyte signal concept was also used to calculate multivariate analytical figures of merit, such as LOD, selectivity, and sensitivity. The method was successfully applied to the simultaneous determination of anthazoline and naphazoline in a commercial eye drop sample. 相似文献
85.
Thierry Benoist Bertrand Estellon Fr��d��ric Gardi Romain Megel Karim Nouioua 《4OR: A Quarterly Journal of Operations Research》2011,9(3):299-316
This paper introduces LocalSolver 1.x, a black-box local-search solver for general 0-1 programming. This software allows OR
practitioners to focus on the modeling of the problem using a simple formalism, and then to defer its actual resolution to
a solver based on efficient and reliable local-search techniques. Started in 2007, the goal of the LocalSolver project is
to offer a model-and-run approach to combinatorial optimization problems which are out of reach of existing black-box tree-search
solvers (integer or constraint programming). Having outlined the modeling formalism and the main technical features behind
LocalSolver, its effectiveness is demonstrated through an extensive computational study. The version 1.1 of LocalSolver can
be freely downloaded at and used for educational, research, or commercial purposes. 相似文献
86.
Ayers J Apetre N Ruzzene M Sabra K 《The Journal of the Acoustical Society of America》2011,129(2):585-588
A single head scanning laser Doppler vibrometer is used for the estimation of the polarization of the first symmetric (S(0)) and antisymmetric (A(0)) Lamb wave modes. The measurements at two known incidence angles are performed in order to resolve the two components of motion. Filtering in the frequency/wavenumber domain of the response recorded along a scan line separates the contributions from each mode and allows the evaluation of the corresponding elliptical trajectories of particle motion. Comparison between measured and analytically estimated trajectories validates the measurement technique and suggests its application for the development of material characterization and diagnostics tools. 相似文献
87.
88.
Pontryagin–Rodygin?s Theorem for slow and fast systems describes the slow drift during the rolling up of the trajectories around the cycles of the fast dynamics. This drift is approximated by the averaging on the cycles. The calculation of this average is generally a difficult task since it requires the knowledge of the closed orbits and their periods. We present two paradigms of three time scale systems where we can overcome this limitation. It is the case of systems the fast dynamics of which have cycles with relaxation presenting or not a canard phenomenon. We can not apply Pontryagin–Rodygin?s Theorem to these systems because their fast equation is itself singularly perturbed. We also investigate the extension of the results to unbounded time intervals. The results are stated classically and proved within the framework of nonstandard analysis. 相似文献
89.
90.
María Abreu-Sepúlveda Dominique E. Williams Ashfia Huq Chetan Dhital Yunchao Li M. Parans Paranthaman Karim Zaghib A. Manivannan 《Ionics》2016,22(3):317-325
Titanium, tantalum-substituted Li7La3Zr2-xAxO12 (LLZO, A?=?Ta, Ti) garnets, and chromium-substituted La(2/3)-xLi3xTi1-yCryO3 (LLTO) perovskites were prepared by a conventional solid-state reaction and the Pechini processes. The desired crystal phases were obtained by varying the calcination temperature and time, as well as the substitution concentration. All samples indicated decomposition of the precursors when heated above 750 °C and formation of the desired phase after heat treatment at higher temperatures. Neutron diffraction data shows the formation of a predominant cubic phase in the case of Ta-LLZO, and monoclinic phase with minor impurity phases for Cr-LLTO. Ionic conductivity for Ti-LLZO (Li7La3Zr1.4Ti0.6O12), Ta-LLZO (Li6.03La3Zr1.533Ta0.46O12), and Cr-LLTO (La(2/3)-xLi3xTi0.9Cr0.1O3) at room temperature were found to be 5.21?×?10?6, 1.01?×?10?6, and 1.2?×?10?4 S cm?1, respectively. The activation energies of the compounds were determined from the Arrhenius plot and were 0.44 eV (Ti0.6-LLZO), 0.54 eV (Ta0.5-LLZO), and 0.20 eV (Cr0.1-LLTO). 相似文献