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91.
The diffusive motions of hydrogen in amorphous Zr2Ni hydrides were observed by181Ta PAC relaxation measurements. The comparison with the experimental data obtained for crystalline Zr2Ni hydride lead to the conclusion that hydrogen loading induce a short-range ordering into the amorphous structure. The absence
of a large distribution of activation energies may be a consequence of such ordering and/or of collective effects in the hydrogen
diffusion processes
Affiliated to the Centre National de la Recherche Scientifique. 相似文献
92.
93.
Ali Bagheri Jonathan Yeow Hamidreza Arandiyan Jiangtao Xu Cyrille Boyer May Lim 《Macromolecular rapid communications》2016,37(11):905-910
The polymerization of the photocleavable monomer, o‐nitrobenzyl methacrylate (NBMA), is investigated using photoinduced electron/energy transfer reversible addition‐fragmentation chain transfer polymerization. The polymerizations under visible red (λ max = 635 nm, 0.7 mW cm−2) and yellow (λ max = 560 nm, 9.7 mW cm−2) light are performed and demonstrate rational evidence of a controlled/living radical polymerization process. Well‐defined poly(o‐nitrobenzyl methacrylate) (PNBMA) homopolymers with good control over the molecular weight and polymer dispersity are successfully synthesized by varying the irradiation time and/or targeted degree of polymerization. Chain extension of a poly(oligo(ethylene glycol) methyl ether methacrylate) macro‐chain transfer agent with NBMA is carried out to fabricate photocleavable amphiphilic block copolymers (BCP). Finally, these self‐assembled BCP rapidly dissemble under UV light suggesting the photoresponsive character of NBMA is not altered during the polymerization under yellow or red light. Such photoresponsive polymers can be potentially used for the remote‐controlled delivery of therapeutic compounds.
94.
J. C. Elicer-Corts R. Contreras D. Boyer M. Pavageau R. H. Hernndez 《Experimental Thermal and Fluid Science》2004,28(8):1205-813
This paper reports the results of a study on temperature inhomogeneities conducted on a thermal plume by using ultrasound scattering as a non-intrusive measurement technique. The plume rises from a metallic disk which can be heated up to 800 °C. The working fluid is air at atmospheric pressure. In the measurement technique, an incoming ultrasound wave is emitted towards the thermal plume. The incident wave is scattered because of non-linear couplings with the flow instabilities present in the measurement region. The scattered wave carries information about those flow instabilities. The technique allows for the retrieving of this information. The shape of the obtained spectrum of temperature fluctuations as a function of wave vector modulus
is consistent with previous theoretical analysis. Three qualitatively different regions were identified: first, a production region characterized by a q2 law; secondly, a region with behavior as per q−3 associated with a buoyancy region and; finally, a dissipation region associated with a q−7 law. These spectral regions characterize the energy transfers mechanisms among the length scales of flow investigated here. A coefficient of anisotropy γ was defined to analyze anisotropic features of the flow. 相似文献
95.
Robson B Li J Dettinger R Peters A Boyer SK 《Journal of computer-aided molecular design》2011,25(5):427-441
A patent data base of 6.7 million compounds generated by a very high performance computer (Blue Gene) requires new techniques
for exploitation when extensive use of chemical similarity is involved. Such exploitation includes the taxonomic classification
of chemical themes, and data mining to assess mutual information between themes and companies. Importantly, we also launch
candidates that evolve by “natural selection” as failure of partial match against the patent data base and their ability to
bind to the protein target appropriately, by simulation on Blue Gene. An unusual feature of our method is that algorithms
and workflows rely on dynamic interaction between match-and-edit instructions, which in practice are regular expressions.
Similarity testing by these uses SMILES strings and, less frequently, graph or connectivity representations. Examining how
this performs in high throughput, we note that chemical similarity and novelty are human concepts that largely have meaning
by utility in specific contexts. For some purposes, mutual information involving chemical themes might be a better concept. 相似文献
96.
Taking pyridine as a prototypal example of biologically important nitrogen bases involved in proton-coupled electron transfers, it is shown with the example of the photochemically triggered oxidation of phenol by Ru(III)(bpy)(3) that this proton acceptor partakes in a concerted pathway whose kinetic characteristics can be extracted from the overall kinetic response. The treatment of these data, implemented by the results of a parallel study carried out in heavy water, allowed the determination of the intrinsic kinetic characteristics of this proton acceptor. Comparison of the reorganization energies and of the pre-exponential factors previously derived for hydrogen phosphate and water (in water) as proton acceptors suggests that, in the case of pyridine, the proton charge is delocalized over a primary shell of water molecules firmly bound to the pyridinium cation. 相似文献
97.
Pardo E Train C Gontard G Boubekeur K Fabelo O Liu H Dkhil B Lloret F Nakagawa K Tokoro H Ohkoshi S Verdaguer M 《Journal of the American Chemical Society》2011,133(39):15328-15331
A complex-as-ligand strategy to get a multifunctional molecular material led to a metal-organic framework with the formula (NH(4))(4)[MnCr(2)(ox)(6)]·4H(2)O. Single-crystal X-ray diffraction revealed that the anionic bimetallic coordination network adopts a chiral three-dimensional quartz-like architecture. It hosts ammonium cations and water molecules in functionalized channels. In addition to ferromagnetic ordering below T(C) = 3.0 K related to the host network, the material exhibits a very high proton conductivity of 1.1 × 10(-3) S cm(-1) at room temperature due to the guest molecules. 相似文献
98.
Milhomme O John C Djedaïni-Pilard F Grandjean C 《The Journal of organic chemistry》2011,76(15):5985-5998
Anthrose is the upstream terminal unit of the tetrasaccharide side chain from a major glycoprotein of Bacillus anthracis exosporium and is part of important antigenic determinants. A novel entry to anthrose-containing antigens and precursors is described. The synthetic route, starting from D(+)-fucose, makes use of intermediates featuring a cyclic sulfite or sulfate function which serves successively as a protecting and a leaving group. 相似文献
99.
100.
Cyrille Grandjean Valérie Santraine Ange Polidori Hélène Gras-Masse Dominique Bonnet 《Tetrahedron letters》2004,45(17):3451-3454
The hydrazone ligation can be used to couple clustered-glycosides or glycomimetics functionalized with a hydrazino group with lipophilic glyoxylyl acid derivatives to give the corresponding amphiphiles in high yield and purity. 相似文献