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991.
Dušan Galanda Ľubomír Mátel Jana Strišovská Silvia Dulanská 《Journal of Radioanalytical and Nuclear Chemistry》2014,299(3):1411-1416
In our scientific research we have monitored mycoremediation’s properties of oyster mushrooms in cultivation on the soil what is contaminated by solutions with radioactive isotopes of 239Pu and 241Am with known activity. We monitored specific activities of absorbed radionuclides in fruiting bodies and chemical forms of radionuclides which were compared to calculated specific activities of two background samples of oyster mushrooms intended for consumer purpose. We determined distributive coefficients between the ground and the fruiting body of oyster mushrooms. The average value which was obtained for the transfer factor for plutonium was 0.72 and for americium 3.97. To evaluate a quantity of absorbed radionuclides we used a method of liquid extraction. The emitting alpha radiation of alpha radionuclides was detected by spectrometry. For defining individual fractions of plutonium and americium that are contained in mushroom bodies was used the sequential leaching method. 相似文献
992.
Andrea Schenkmayerová Marek Bučko Peter Gemeiner Dušana Treľová Igor Lacík Dušan Chorvát Jr. Pavel Ačai Milan Polakovič Lukáš Lipták Martin Rebroš Michal Rosenberg Vladimír Štefuca Vilém Neděla Eva Tihlaříková 《Applied biochemistry and biotechnology》2014,174(5):1834-1849
Direct comparison of key physical and chemical-engineering properties of two representative matrices for multipurpose immobilisations was performed for the first time. Polyvinyl alcohol lens-shaped particles LentiKats® and polyelectrolyte complex microcapsules were characterised by advanced techniques with respect to the size distribution of the particles, their inner morphology as revealed by fluorescent probe staining, mechanical resistance, size-exclusion properties, determination of effective diffusion coefficient and environmental scanning electron microscope imaging. While spherical polyelectrolyte complex microcapsules composed of a rigid semipermeable membrane and a liquid core are almost uniform in shape and size (diameter of 0.82 mm; RSD?=?5.6 %), lens-shaped LentiKats® are characterised by wider size distribution (diameter of 3.65 mm; RSD?=?10.3 % and height of 0.341 mm; RSD?=?32.3 %) and showed the same porous structure throughout their whole volume at the mesoscopic (micrometre) level. Despite differences in their inner structure and surface properties, the pore diameter of?~?2.75 nm for regular polyelectrolyte complex microcapsules and?~?1.89 nm for LentiKats® were similar. These results were used for mathematical modelling, which provided the estimates of the effective diffusion coefficient of sucrose. This value was 1.67?×?10?10 m2 s?1 for polyelectrolyte complex microcapsules and 0.36?×?10?10 m2 s?1 for LentiKats®. Recombinant cells Escherichia coli-overexpressing enzyme cyclopentanone monooxygenase were immobilised in polyelectrolyte complex microcapsules and LentiKats® for comparison of their operational stability using model Baeyer–Villiger oxidation of (±)-cis-bicyclo [3.2.0] hept-2-en-6-one to regioisomeric lactones as important chiral synthons for potential pharmaceuticals. Both immobilisation matrices rendered high operational stability for whole-cell biocatalyst with no reduction in the biooxidation rate over 18 repeated reaction cycles. 相似文献
993.
Jingjing Zhu Yue Wang Zhenxiang Li Si’an Fang Junbo Zhang 《Journal of Radioanalytical and Nuclear Chemistry》2014,302(1):211-216
In this study, phenylalanine dithiocarbamate (PHEDTC) ligand was successfully synthesized and then radiolabeled with [99mTcO]3+ core and [99mTc≡N]2+ core to produce 99mTcO–PHEDTC and 99mTcN–PHEDTC, respectively. Both complexes were prepared with high radiochemical purity and had good stability. The partition coefficient results showed they were hydrophilic, while 99mTcN–PHEDTC was more hydrophilic than 99mTcO–PHEDTC. The biodistribution study in mice bearing S 180 tumor showed that 99mTcO–PHEDTC and 99mTcN–PHEDTC had high tumor uptake at 2 h post-injection, 1.91 and 1.21, respectively. The good uptake and retention in tumor together with favorable tumor-to-muscle ratios make them promising candidates for further evaluation as potential tumor imaging agents. 相似文献
994.
In this paper, the tangential and normal discontinuities at the interface between the scatterer and the matrix are independently modeled, and these relative displacements are directly proportional to the corresponding components of tractions at the interface. The generation of full band-gaps is investigated on the basis of the derived imperfect interface conditions for a sonic plate with an array of acoustic piezoceramic hollow spheres scatterers embedded in an epoxy matrix. The scatterers are made from functionally graded materials with radial polarization. Numerical evaluation has shown that imperfect interface may have a significant effect on the increasing of the length of the full band-gaps. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
995.
A. V. Geliev Kh. D. Do B. V. Egorov Yu. E. Markachev K. B. Tereshkina D. M. Shogin V. I. Khromov 《Russian Journal of Physical Chemistry B, Focus on Physics》2011,5(1):124-130
The correlation dependence of the critical Reynolds number of the laminar-turbulent transition on the equilibrium constant
of dimerization in a gas during gas flow in dry or sprayed tubes is presented. A new approach to this problem is suggested
related to the use of the quasi-chemical cluster gas model developed by the authors. 相似文献
996.
D. Ieşan 《Nonlinear Analysis: Real World Applications》2011,12(1):513-524
In this paper we present a theory of mixtures of elastic solids with initial stresses and initial heat flux. First, we establish the equations governing the small deformations superposed on nonlinear deformations of mixtures. Then, we derive the basic equations of prestressed mixtures with initial heat flux. The continuous dependence of the solutions upon initial data and body supplies is established. The theory is used to study the deformation of a prestressed spherical shell subjected to constant pressures. 相似文献
997.
Miroslav Bartušek Mariella Cecchi Zuzana Došlá Mauro Marini 《Central European Journal of Mathematics》2011,9(1):184-195
Globally positive solutions for the third order differential equation with the damping term and delay,
$
x' + q(t)x'(t) - r(t)f(x(\phi (t))) = 0,
$
x' + q(t)x'(t) - r(t)f(x(\phi (t))) = 0,
相似文献
998.
Siloxane-terminated solubilizing side chains: bringing conjugated polymer backbones closer and boosting hole mobilities in thin-film transistors 总被引:1,自引:0,他引:1
Mei J Kim do H Ayzner AL Toney MF Bao Z 《Journal of the American Chemical Society》2011,133(50):20130-20133
We introduce a novel siloxane-terminated solubilizing group and demonstrate its effectiveness as a side chain in an isoindigo-based conjugated polymer. An average hole mobility of 2.00 cm(2) V(-1) s(-1) (with a maximum mobility of 2.48 cm(2) V(-1) s(-1)), was obtained from solution-processed thin-film transistors, one of the highest mobilities reported to date. In contrast, the reference polymer with a branched alkyl side chain gave an average hole mobility of 0.30 cm(2) V(-1) s(-1) and a maximum mobility of 0.57 cm(2) V(-1) s(-1). This is largely explained by the polymer packing: our new polymer exhibited a π-π stacking distance of 3.58 ?, while the reference polymer showed a distance of 3.76 ?. 相似文献
999.
Ultrahigh mobility in polymer field-effect transistors by design 总被引:1,自引:0,他引:1
Tsao HN Cho DM Park I Hansen MR Mavrinskiy A Yoon do Y Graf R Pisula W Spiess HW Müllen K 《Journal of the American Chemical Society》2011,133(8):2605-2612
In this article, the design paradigm involving molecular weight, alkyl substituents, and donor-acceptor interaction for the poly[2,6-(4,4-bis-alkyl-4H-cyclopenta[2,1-b;3,4-b']-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (cyclopentadithiophene-benzothiadiazole) donor-acceptor copolymer (CDT-BTZ) toward field-effect transistors (FETs) with ultrahigh mobilities is presented and discussed. It is shown that the molecular weight plays a key role in improving hole mobilities, reaching an exceptionally high value of up to 3.3 cm(2) V(-1) s(-1). Possible explanations for this observation is highlighted in conjunction with thin film morphology and crystallinity. Hereby, it is found that the former does not change, whereas, at the same time, crystallinity improved with ever growing molecular weight. Furthermore, other important structural design factors such as alkyl chain substituents and donor-acceptor interaction between the polymer backbones potentially govern intermolecular stacking distances crucial for charge transport and hence for device performance. In this aspect, for the first time we attempt to shed light onto donor-acceptor interactions between neighboring polymer chains with the help of solid state nuclear magnetic resonance (NMR). On the basis of our results, polymer design principles are inferred that might be of relevance for prospective semiconductors exhibiting hole mobilities even exceeding 3 cm(2) V(-1) s(-1). 相似文献
1000.
Sol-gel based alumina powders with catalytic applications 总被引:1,自引:0,他引:1
Maria Cri?an Maria ZaharescuValluri Durga Kumari Machiraju SubrahmanyamDorel Cri?an Nicolae Dr?ganM?lina R?ileanu Mihaela JitianuAdriana Rusu Gullapelli SadanandamJakkidi Krishna Reddy 《Applied Surface Science》2011,258(1):448-455
The sol-gel process provides a new approach to the preparation of oxide materials and offers many advantages for making catalysts. Since homogeneous mixing can be achieved at the molecular scale, the chemical reactivity of the oxide surface can be greatly enhanced; thus powders with high surface area and optimized pore size distribution can be obtained at low temperatures. In the present work NiO/Al2O3 sol-gel catalysts were obtained by simultaneous gelation of aluminium isopropoxide and nickel nitrate. A comparative study with pure sol-gel alumina was also realized. By physical-structural studies the changes induced by the introduction of the Ni precursor, before and after aluminium alkoxide hydrolysis were highlighted. The introduction of Ni at the beginning of the reaction favors γ-Al2O3 crystallization. When Ni is added at the end of reaction, it delays the alumina crystallization and induces the disorder of the lattice. The obtained Ni doped sol-gel derived alumina has been used as catalyst in the finished form for glycerol reforming to generate H2 for fuel cell applications. Some evaluation results of Ni-doped alumina combined with TiO2 in photocatalytic glycerol reforming reaction have been included. 相似文献
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