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991.
Russian Chemical Bulletin - For the first time, quinazolin-4(3H)-one-based cationic surfactants were prepared and fully characterized by IR and NMR spectroscopic techniques and elemental analysis.... 相似文献
992.
Xuping Li Gleb Baryshnikov Longjiang Ding Xiaoyan Bao Xin Li Jianjun Lu Miaoqing Liu Shen Shen Mengkai Luo Man Zhang Hans gren Xudong Wang Liangliang Zhu 《Angewandte Chemie (International ed. in English)》2020,59(19):7548-7554
Developing luminescent probes with long lifetime and high emission efficiency is essential for time‐resolved imaging. However, the practical applications usually suffer from emission quenching of traditional luminogens in aggregated states, or from weak emission of aggregation‐induced emission type luminogens in monomeric states. Herein, we overcome this dilemma by a rigid‐and‐flexible alternation design in donor–acceptor–donor skeletons, to achieve a thermally activated delayed fluorescence luminogen with high emission efficiency both in the monomeric state (quantum yield up to 35.3 %) and in the aggregated state (quantum yield up to 30.8 %). Such a dual‐phase strong and long‐lived emission allows a time‐resolved luminescence imaging, with an efficiency independent of probe pretreatment and probe concentration. The findings open opportunities for developing luminescent probes with a usage in larger temporal and spatial scales. 相似文献
993.
The recently modified Faddeev-Jackiw formalism for systems having one chain of four levels of only second-class constraints is applied to the non-triviala=1 bosonized chiral Schwinger model in (1+1) dimensions as well as to one mechanical system. The sets of obtained constraints are in agreement with Dirac’s canonical formulation. 相似文献
994.
S. V. Nesterov S. Kücükyavuz A. M. Önal 《Journal of Radioanalytical and Nuclear Chemistry》1999,240(3):953-957
Radiation induced chain addition of allylbenzene to 1,4-dioxane has been studied by IR-, UV-, mass-, NMR- and ESR-spectrometry.
Efficiency of the addition depends on the concentration of monomer and it has an optimum atC
monom<0.125M. Apparently, upper concentration limit of the reaction is caused by absorbed energy transfer on the molecule, of monomer
followed by energy deactivation. Radiation-chemical yields of the product are 12 and 31 molec./100 eV for 0.125M and 0.07M
solution, respectively. The value ofG
prod. is an evidence of chain character of the process. 相似文献
995.
The elastoplastic stress state of a laminated stainless-steel-fiber-reinforced aluminum-matrix plates, with or without a hole,
subjected to a pressure on their top is examined by using the finite-element method. The analysis is carried out for three
layouts: (0/90/0/90)s, (45/-45/45/-45)s, and (30/60/30/60)s. The Newton-Raphson method is used to solve the nonlinear problem. The distributions of equivalent stresses and the plastic
zones of the plates without a hole and with a hole of various diameters are determined.
Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 42, No. 4, pp. 531–544, July–August, 2006. 相似文献
996.
997.
S. V. Nesterov S. Kücükyavuz A. M. Önal 《Journal of Radioanalytical and Nuclear Chemistry》1999,242(1):91-96
Radiation induced addition of allylbenzene to morpholine in liquid state was investigated by UV-, IR-spectroscopy and GS/mass
spectrometry. Conversion of monomer depends on its initial concentration in the solution and this value is maximum for 0.05M
solution. Radiation chemical yield of the product,G
prod
, increases with concentration of allylbenzene and for 0.15M solution it is equal approximately 9.7 molec/100 eV. This value
points on chain character of the process. Final product was identified by electron impact mass-spectrometry. The scheme of
the EI induced fragmentation of product is proposed. 相似文献
998.
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1000.