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51.
We study the variational equations for solitons in noncommutative scalar field theories in an even number of spatial dimensions. We prove the existence of spherically symmetric solutions for a sufficiently large noncommutativity parameter θ and we prove the absence of spherically symmetric solutions for small θ. 相似文献
52.
53.
Sylwia Studzińska Sandra Mounicou Joanna Szpunar Ryszard Łobiński Bogusław Buszewski 《Analytica chimica acta》2015
This text presents a novel method for the separation and detection of phosphorothioate oligonucleotides with the use of ion pair ultra high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry The research showed that hexafluoroisopropanol/triethylamine based mobile phases may be successfully used when liquid chromatography is coupled with such elemental detection. However, the concentration of both HFIP and TEA influences the final result. The lower concentration of HFIP, the lower the background in ICP-MS and the greater the sensitivity. The method applied for the analysis of serum samples was based on high resolution inductively coupled plasma mass spectrometry. Utilization of this method allows determination of fifty times lower quantity of phosphorothioate oligonucleotides than in the case of quadrupole mass analyzer. Monitoring of 31P may be used to quantify these compounds at the level of 80 μg L−1, while simultaneous determination of sulfur is very useful for qualitative analysis. Moreover, the results presented in this paper demonstrate the practical applicability of coupling LC with ICP-MS in determining phosphorothioate oligonucleotides and their metabolites in serum within 7 min with a very good sensitivity. The method was linear in the concentration range between 0.2 and 3 mg L−1. The limit of detection was in the range of 0.07 and 0.13 mg L−1. Accuracy varied with concentration, but was in the range of 3%. 相似文献
54.
55.
This study describes the influence of melamine polyphosphate (MPP) flame retardant addition on layered structure of virgin sodium montmorillonite (MMT) in PA6/MMT system obtained in extrusion process. It was found that the extrusion of the PA6/MMT binary system in co‐rotating twin screw extruder gives intercalated clay nanocomposites, while during extrusion of ternary PA6/MMT/MPP composite, full exfoliation of clay was obtained in the system. Structure of the composites was proved utilizing wide angle X‐ray scattering and transmission electron microscopy techniques. Exfoliation of MMT in ternary PA6/MMT/MPP system was also confirmed by rheological studies (viscosity and creep measurements) which were carried out using rotational rheometer. Young's modulus of PA6/MMT/MPP was found to be ~25% greater comparing to PA6/MPP of the same filling level. Cone calorimetry experiments proved decrease of heat release rate peak of PA6/MMT/MPP by ~55% comparing to PA6/MPP with the same total filling level. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
56.
We study a collisionless kinetic equation describing density distribution function of the position and velocity of particles moving in a slab with finite thickness and with a partly diffusive boundary reflection. In particular, we deal with existence of an invariant density and with the convergence to the equilibrium. We also study the long time behavior of densities when the equilibrium does not exists. 相似文献
57.
Direct aldol reactions of 4-methyl-1-piperidone, tropinone and granatanone (pseudopelletierine) take place spontaneously in the presence of water without any catalyst or additional reagents. The anti/syn-diastereoselectivity of the aqueous aldol reaction depends on the amount of water used. The syn-selectivity of the reaction is probably due to the thermodynamic control. Excellent atom economy and low E factors together with anti-selectivity as high as 98:2 for the tropinone aldol were obtained. 相似文献
58.
The paper presents elastic barrier materials developed at the INF which play a role of filling and fire barrier material at the same time in upholstery furniture, reducing the development and spread of fire on flammable materials. The presented results of flammability and biophysical tests confirm the comfort of products.The developed barrier materials use natural fibres (wool, flax FR) characterized by good air permeability, hygroscopicity, moisture transport, elimination of electrostatic charges and have effect on climate of interiors also when blended with thermostable fibres such as Polyacrylate. These flexible structures based on blend of natural fibres and thermostable fibres with at least two barrier effects i.e. durable resistance to fire, thermal insulation, control of electrostatic phenomena. 相似文献
59.
Bani-Yaseen AD Kawaguchi T Price AK Culbertson CT Jankowiak R 《Analytical and bioanalytical chemistry》2011,399(1):519-524
Catechol estrogen-derived DNA adducts are formed as a result of the reaction of catechol estrogen metabolites (e.g., catechol
estrogen quinones) with DNA to form depurinating adducts. Developing a new methodology for the detection of various DNA adducts
is essential for medical diagnostics, and to this end, we demonstrate the applicability of on-chip capillary electrophoresis
with an integrated electrochemical system for the separation and amperometric detection of various catechol estrogen-derived
DNA adducts. A hybrid PDMS/glass microchip with in-channel amperometric detection interfaced with in situ palladium decoupler
is utilized and presented. The influence of buffer additives along with the effect of the separation voltage on the resolving
power of the microchip is discussed. Calibration plots were constructed in the range 0.4–10 μM with r
2 ≥ 0.999, and detection limits in the attomole range are reported. These results suggest that on-chip analysis is applicable
for analyzing various DNA adducts as potential biomarkers for future medical diagnostics. 相似文献
60.
Bazarnik M Henzl J Czajka R Morgenstern K 《Chemical communications (Cambridge, England)》2011,47(27):7764-7766
We present a successful attempt of decoupling a dye molecule from a metallic surface via physisorption for enabling direct photoisomerization. Effective switching between the isomers is possible by exposure to UV light via the rotation pathway. 相似文献