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71.
Ivana Pasáková Petra Kovaříková Radim Kučera Jiří Klimeš Jaroslav Sochor Alexandr Hrabálek 《Chromatographia》2009,69(9-10):977-983
A new, sensitive LC–MS method for evaluation of the purity of Transkarbam 12 (T12), a novel and highly effective accelerant of transdermal penetration, has been developed and validated. T12 and its impurities (6-aminohexanoic acid, AH, ε-caprolactam, CA, and dodecyl 6-(6-aminohexanamido)hexanoate, DAH) were characterized by MS and MS–MS analysis. Separation was achieved on a 150 mm × 3 mm, 5-μm particle, phenyl–hexyl column. The mobile phase was a gradient prepared from water, formic acid, and acetonitrile. The method was validated within the concentration range 50–250 ng mL?1; correlation coefficients were >0.998. The accuracy of the method was from 98.6–105.0% for AH, 102.6–104.8% for CA, and 97.9–100.9% for DAH. Precision was in the range 3.19–4.42% for AH, 3.22–5.81% for CA, and 4.8–8.78% for DAH. The selectivity of the method and sample stability were also confirmed. The practical applicability of the method was proven by analysis of T12 bulk substance. 相似文献
72.
Jaroslav Kahovec Frantisek Lednický 《Journal of Macromolecular Science: Physics》2013,52(3-4):vii-viii
73.
Jaroslav Holoubek Frantisek Lednický Blahoslav Sedlcek Josef Mike 《Journal of Polymer Science.Polymer Physics》1986,24(8):1823-1837
An analysis is given of dichromatic speckle patterns formed by small-angle scattered light in the illumination of optically heterogeneous systems with light of two nearby wavelengths. The existence of the radial-fibrillar appearance of the speckle patterns is explained; it is shown that the occurrence of the radial-fibrillar “structure” corresponds to the measurable correlation of dichromatic speckle patterns as specified by the spectral spatial cross-correlation function of intensity fluctuations. A measurement of speckle-pattern correlation to determine σz (the standard deviation of optical path fluctuations due to the passage of coherent light through a layer of heterogeneous material) is described, and the relations between σz and the structural parameters for two simple types of heterogeneous materials are discussed. Experimental results obtained with a series of samples of polyethylene filled with CaCO3 are in comparatively good agreement with theoretical values. 相似文献
74.
Jaroslav Milbauer 《Fresenius' Journal of Analytical Chemistry》1918,57(4):161-162
Ohne Zusammenfassung 相似文献
75.
This contribution is focused on an acceleration of branch and bound algorithms for the uncapacitated facility location problem. Our approach is based on the well-known Erlenkotters’ procedures and Körkels’ multi-ascent and multi-adjustment algorithms, which have proved to be the efficient tools for solving the large-sized instances of the uncapacitated facility location problem. These two original approaches were examined and a thorough analysis of their performance revealed how each particular procedure contributes to the computational time of the whole algorithms. These analyses helped us to focus our effort on the most frequent procedures. The unique contribution of this paper is a new dual ascent procedure. This procedure leads to considerable acceleration of the lower bound computation process and reduces the resulting computational time. To demonstrate more efficient performance of amended algorithms we present the results of extensive numerical experiments. 相似文献
76.
77.
Pradeep K. Jaiswal Vashundhra Sharma Jaroslav Prikhodko Irina V. Mashevskaya Sandeep Chaudhary 《Tetrahedron letters》2017,58(22):2077-2083
For the first time, an efficient, simple, synthetic green protocol for the one-pot synthesis of functionalized 2-oxo-benzo[1,4]oxazines 24–29 in water under ultrasound irradiation is presented. As compared to conventional methods, the present protocol avoids traditional chromatography and purification steps and furnished the target molecules in excellent yields (upto 98%) with no side products. The methodology was also demonstrated on gram scale synthesis. Moreover, functionalized 2-oxo-quinoxaline analogues 31–33, another class of bio-active heterocyclic scaffolds, were also prepared using this method. For the first time, this protocol was successfully applied in the synthesis of the anticancer indole alkaloid, Cephalandole A 35. 相似文献
78.
Jaroslav Menčík 《Meccanica》2007,42(1):19-29
The paper reviews the current state of the depth-sensing indentation (sometimes called nanoindentation), where the information
on material behaviour and properties is obtained from the indenter load and depth, measured continuously during loading and
unloading. It is shown how the contact parameters and principal characteristics are determined using pointed or spherical
indenters. Indentation tests can be used for the measurement of hardness and elastic modulus, and also of the yield stress
and for the construction of stress–strain diagrams, for the determination of the work of indentation and its components. Most
devices use monotonic loading and unloading, but some also enable measurement under a small harmonic signal added to the basic
monotonously increasing load. This makes possible continuous measurement of contact stiffness and the study of dynamic properties
and the determination of properties of coatings. One section is devoted to the measurement on viscoelastic-plastic materials,
where the delayed deforming must be considered during the measurement as well as in data evaluation. Instrumented indentation
can also be used for the study of creep under high temperatures. The paper also discusses the errors arising in depth-sensing
measurements and informs briefly about some other possibilities of the method. 相似文献
79.
80.
Černý Miroslav Šandera Pavel Pokluda Jaroslav 《Czechoslovak Journal of Physics》1999,49(10):1495-1501
Ab initio calculation of ideal strength of cubic crystals under three-axial tension was performed using the LMTO-ASA method. Computed values are in a good agreement with those obtained previously by means of semi-empirical polynomial approach. The values of equilibrium lattice parameter obtained in the framework of ab initio method are well comparable with the experimental data whereas a less satisfactory agreement was achieved in the case of bulk moduli. 相似文献