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1.
Journal of Applied Spectroscopy - Solvatochromic shifts of absorption bands are determined in a series of solvents of different nature for two free-base corroles with different peripheral... 相似文献
2.
3.
Gladkov L. L. Klenitsky D. V. Vershilovskaya I. V. Maes W. Kruk M. M. 《Journal of Applied Spectroscopy》2022,89(3):426-432
Journal of Applied Spectroscopy - The aromaticity in the lowest triplet T1-state of NH-tautomers of corrole free bases with different peripheral substitution architecture was investigated using... 相似文献
4.
Tuning of the Temperature Window for Unit‐Cell and Pore‐Size Enlargement in Face‐Centered‐Cubic Large‐Mesopore Silicas Templated by Swollen Block Copolymer Micelles 下载免费PDF全文
Dr. Yingyu Li Jinhui Yi Prof. Michal Kruk 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(36):12747-12754
The unit‐cell size and pore diameter as functions of temperature are investigated in the syntheses of FDU‐12 silicas with face‐centered cubic structure templated by Pluronic (PEO‐PPO‐PEO) block copolymer micelles swollen by toluene. The temperature range in which the unit‐cell size and pore size strongly increase as temperature decreases is correlated with the critical micelle temperature (CMT) of the surfactant. While Pluronic F127 affords a wide range of unit‐cell parameters (28–51 nm) and pore diameters (16–32 nm), it renders moderately enlarged pore sizes at 25 °C. The use of Pluronic F108 with higher CMT affords FDU‐12 with very large unit‐cell size (~49 nm) and large pore diameter (27 nm) at 23 °C. Large unit‐cell size (40–41 nm) and pore size (22 nm) were obtained even at 25 °C. The application of Pluronics F87 and F88 with much smaller molecular weights and higher CMTs also allows one to synthesize FDU‐12 with quite large unit‐cell parameters and pore sizes at room temperature. The present work demonstrates that one can judiciously select Pluronic surfactants with appropriate CMT to shift the temperature range in which the pore diameter is readily tunable. 相似文献
5.
On Free Nonlinear Vibrations of Fluid-Filled Cylindrical Shells with Multiple Natural Frequencies 总被引:1,自引:0,他引:1
Nonlinear free vibrations of a cylindrical shell fully filled with a perfect incompressible fluid are studied. The case is
examined where two natural frequencies of the shell are close
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Published in Prikladnaya Mekhanika, Vol. 41, No. 10, pp. 127–138, October 2005 相似文献
6.
On the spectrum of natural frequencies of circular cylindrical shells completely filled with a fluid
The natural frequencies of cylindrical shells filled with a fluid and having the ends either simply supported or clamped are
determined. Conditions are studied under which the natural frequencies of the shell are close or multiple
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Translated from Prikladnaya Mekhanika, Vol. 42, No. 5, pp. 42–49, May 2006. 相似文献
7.
Yu. B. Ivanova Dao Tkhe Nam M. M. Kruk C. A. Syrbu 《Russian Journal of General Chemistry》2013,83(6):1155-1159
The formation of deprotonated forms of tetra(t-butyl)phthalocyanine ((H2 tButPc) and octa(pentoxy)-phthalocyanine (H2OAmPc) in the system acetonitrile-1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) at 298 K was studied by the method of spectrophotometric titration. With increasing DBU concentration sequential formation occurs of both mono- and douby deprotonated forms. The introduction of pentoxy groups into the fused benzene rings leads to a significant decrease in the acidity of the tetrapyrrole macrocycle compared with the tert-butyl substitution. The interaction of douby deprotonated forms of the phthalocyanines with zinc diacetate leads to the formation of metal complexes, the chelation constant of the latter is shown to correlate with the acidity of NH-protons in the nucleus of the macrocycle. For the chelation of more acidic tetra(t-butyl)-phthalocyanine an equimolar concentrations of zinc diacetate is sufficient, while the less acidic octa(pentoxy)-phthalocyanine requires almost 6-fold excess. 相似文献
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9.
Following up transfer of strontium from soil to plants requires determination of isotope in the surface layer of soil and
a chosen plant. The most endangered food products are plants including commonly grown grain, which constitutes a basic feeding
component for both people and animals. Indeed large amounts of 137Cs, 90Sr get into organisms of people and animals with the food, therefore determination of radioactivity of elements in food products
and animal fodder is very essential. Choice of proper diet allows to limit the level of human organism denaturation. The aim
of this paper was to study relocation of 90Sr, 137Cs, 40K isotopes from soil to grain and then from grain to food products. There were investigated soil, wheat, barley, groats, flour,
macaroni and breakfast flakes. Based on the obtained results there were calculated effective weighted doses [nSv] from consumption
of 1 kg of a product for different age groups. 相似文献
10.
The aim of this article was to present the studies of radiological level of some commercial dairy products in Mazovian, Kuyavian—Pomeranian
and Lublin regions. They were carried out for 27 commercial dairy products such as two specimens of lean cottage cheese, three
specimens of cottage cheese containing a limited percentage of fat, three specimens of fat cottage cheese, three specimens
of milk containing 3.2% of fat, three specimens of milk containing 2.0% of fat, two specimens of sour cream containing 12%
of fat, three specimens of sour cream containing 18% of fat, one specimen of 30% whipping cream, two specimens of homogenized
(strawberry and vanilla) cheese, three specimens of hard rennet cheese, one specimen of powdered milk, one specimen of goat
milk. For the given commercial dairy products there were calculated effective doses (μSv) obtained after consumption of 1 kg
contaminated product for different age groups. 相似文献