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991.
Dr. Milan R. Milovanović Dr. Quentin Dherbassy Dr. Joanna Wencel-Delord Prof. Dr. Françoise Colobert Prof. Dr. Snežana D. Zarić Dr. Jean-Pierre Djukic 《Chemphyschem》2020,21(18):2136-2142
To figure out the possible role of 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP) as well as to provide reference thermochemical data in solution, the formation of Lewis acid-base complexes between HFIP (Lewis acid) and a series of 8 different Lewis bases (3 sulfoxides, 3 Nsp2 pyridine derivatives, 1 aromatic amine, 1 cyclic aliphatic ether) was examined by isothermal titration calorimetry (ITC) experiments and static density functional theory augmented with Dispersion (DFT−D) calculations. Measured ITC association enthalpy values (ΔHa) lie between −9.3 and −14 kcal mol−1. Computations including a PCM implicit solvation model produced similar exothermicity of association of all studied systems compared to the ITC data with ΔHa values ranging from −8.5 to −12.7 kcal mol−1. An additional set of calculations combining implicit and explicit solvation by chlorobenzene of the reactants, pointed out the relatively low interference of the solvent with the HFIP-base complexation: its main effect is to slightly enhance the Gibbs energy of the HFIP-Lewis base association. It is speculated that the interactions of bulk HFIP with Lewis bases therefore may significantly intervene in catalytic processes not only via the dynamic microstructuring of the medium but also more explicitly by affecting bonds’ polarization at the Lewis bases. 相似文献
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Theranostics: Polymer Capsules as a Theranostic Tool for a Universal In Vitro Screening Assay—The Case of Lysosomal Storage Diseases (Part. Part. Syst. Charact. 11/2015) 下载免费PDF全文
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Mariusz Barczak Ryszard Dobrowolski Joanna Dobrzyńska Emil Zięba Andrzej Dąbrowski 《Adsorption》2013,19(2-4):733-744
Two groups of amine-functionalized organosilicas have been synthesized: amorphous polysiloxane xerogels (APX) and ordered mesoporous organosilicas (OMO) by co-condensation of tetraethoxysilane and appropriate alkoxysilanes: aminopropyltriethoxysilane and N-[3-(trimethoxysilyl)propyl]ethylenediamine. The obtained materials were characterized by sorption measurements, X-ray diffractometry, elemental analysis, transmission electron microscopy, and scanning electron microscopy. The OMO samples have well developed porous structure—the values of specific surface area are in the range 740–840 m2/g. While the APX samples are less porous having the corresponding values in the range 280–520 m2/g. The sizes of the ordered mesopores of OMO are in the range 5.9–6.5 nm while for the APX they are 2.9–12.1 nm indicating structural differences between both groups of the samples. All samples were tested as the sorbents of Pt(II) ions. The influence of various parameters such as pH, contact time, equilibrium concentration on Pt(II) adsorption ability onto prepared adsorbents was studied in detail. Additionally, the effect of chloride concentration on Pt(II) adsorption was investigated. The values of static sorption capacities were in the range of 32–102 mgPt(II)/g and 20–139 mgPt(II)/g for OMO and APX series, respectively. 相似文献
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Das S Sherwin BD Aguirre P Appel JW Bond JR Carvalho CS Devlin MJ Dunkley J Dünner R Essinger-Hileman T Fowler JW Hajian A Halpern M Hasselfield M Hincks AD Hlozek R Huffenberger KM Hughes JP Irwin KD Klein J Kosowsky A Lupton RH Marriage TA Marsden D Menanteau F Moodley K Niemack MD Nolta MR Page LA Parker L Reese ED Schmitt BL Sehgal N Sievers J Spergel DN Staggs ST Swetz DS Switzer ER Thornton R Visnjic K Wollack E 《Physical review letters》2011,107(2):021301
We report the first detection of the gravitational lensing of the cosmic microwave background through a measurement of the four-point correlation function in the temperature maps made by the Atacama Cosmology Telescope. We verify our detection by calculating the levels of potential contaminants and performing a number of null tests. The resulting convergence power spectrum at 2° angular scales measures the amplitude of matter density fluctuations on comoving length scales of around 100 Mpc at redshifts around 0.5 to 3. The measured amplitude of the signal agrees with Lambda cold dark matter cosmology predictions. Since the amplitude of the convergence power spectrum scales as the square of the amplitude of the density fluctuations, the 4σ detection of the lensing signal measures the amplitude of density fluctuations to 12%. 相似文献
1000.
Lead phosphate glasses containing Eu(3+) and Dy(3+) have been studied. Local structure was verified using Fourier transform (FT)-IR spectroscopy. Emission bands of Eu(3+) and Dy(3+) ions in lead phosphate glasses are observed in the visible spectral range, which correspond to 5D0→7F(J) (J=0,1,2,4) and 4F(9/2)→6H(J/2) (J=15,13,11) transitions, respectively. Shorter luminescence decays from excited states of Eu(3+) and Dy(3+0 are due to the presence of PbO in phosphate glass. 相似文献