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排序方式: 共有507条查询结果,搜索用时 62 毫秒
61.
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.
62.
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
63.
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
64.
65.
The nuclear quadrupole relaxation of 181Ta in ZrO29 mole% Y2O3 has been measured by time differential angular correlations between 350 and 1150°C. The results are consistent with a distribution of the activation energy controlling the local motion of oxygen vacancies. 相似文献
66.
F. Vila M. Boyer G. Gronchi Y. Duccini O. Santero P. Tordo 《Tetrahedron letters》1984,25(21):2215-2218
Pentamethoxynitrosobenzene (PMeONB) has been prepared and its use as a spin-trapping (ST) agent has been investigated. Its solubility is adequate for ST in most organic solvents; compared with the routinely used aryl nitroso compounds, PMeONB is more dissociated into the active monomeric form in solution; the potential windows are of the same order of magnitude. Its spin adduct ESR spectra give move information on the trapped radical than those of any other ST agent. 相似文献
67.
The title radicals have been generated by hydrogen abstraction from the corresponding hydroxylamines in benzene solution. In the absence of oxygen these radicals are extremely persistent and their esr data (aN14, aN15 and aC13, determined without isotopic enrichment) are characteristic of a electronic configuration. 相似文献
68.
A discussion is given of the relation between the maximum functionaltheorem and Schwinger's variational principle, and it is shownthat the bound given by Schwinger's principle is better thanor the same as that given by the maximum functional theorem. 相似文献
69.
Hydrosilylation of alcohols has been carried out in molten dodecylammonium propionate at low temperature (70°C). The salt is used as solvent and as catalyst. 相似文献
70.