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排序方式: 共有213条查询结果,搜索用时 15 毫秒
31.
We consider the so-called Ladyzhenskaya model of incompressible fluid, with an additional artificial smoothing term ?Δ3. We establish the global existence, uniqueness, and regularity of solutions. Finally, we show that there exists an exponential attractor, whose dimension we estimate in terms of the relevant physical quantities, independently of ? > 0. 相似文献
32.
This paper establishes a central limit theorem and an invariance principle for a wide class of stationary random fields under natural and easily verifiable conditions. More precisely, we deal with random fields of the form Xk=g(εk−s,s∈Zd), k∈Zd, where (εi)i∈Zd are iid random variables and g is a measurable function. Such kind of spatial processes provides a general framework for stationary ergodic random fields. Under a short-range dependence condition, we show that the central limit theorem holds without any assumption on the underlying domain on which the process is observed. A limit theorem for the sample auto-covariance function is also established. 相似文献
33.
34.
Lagrangian and Hamiltonian formalisms for coupled higher-order elements: theory,modeling, simulation
Nonlinear Dynamics - In this work, the definition of the constitutive relation of a classical higher-order two-terminal element from Chua’s table is extended to the coupled element. The way... 相似文献
35.
Marta Ambrová Jana Jurišová Alexandra Sýkorová Dalibor Uher Vladimír Danielik Ján Híveš 《Chemical Papers》2008,62(2):154-159
The electrochemical behaviour of the LiF-La2O3 and LiF-CaF2-La2O3 systems was investigated by means of cyclic voltammetry. Several types of working electrodes (spectrographic pure graphite,
W, Mo, Ni, Cu) were used. It was found that chemical reactions take place in the system during the dissolution of lanthanum
oxide. The reduction of lithium cations occurred at the most positive potential from the species formed in the melt on ‘inert’
cathodes (W, Mo). The reactive cathodes (Cu, Ni) allowed the lanthanum deposition with depolarisation. 相似文献
36.
Jesús Alberto Afonso Urich Viktoria Marko Katharina Boehm Raymar Andreína Lara García Dalibor Jeremic Amrit Paudel 《Molecules (Basel, Switzerland)》2021,26(21)
A novel and efficient stability-indicating, reverse phase ultra-performance liquid chromatographic (UPLC®) analytical method was developed and validated for the determination of hexoprenaline in an injectable dosage form. The development of the method was performed using analytical quality by design (AQbD) principles, which are aligned with the future requirements from the regulatory agencies using AQbD principles. The method was developed by assessing the impact of ion pairing, the chromatographic column, pH and gradient elution. The development was achieved with a Waters Acquity HSS T3 (50 × 2.1 mm i.d., 1.8 µm) column at ambient temperature, using sodium dihydrogen phosphate 5 mM + octane-1-sulphonic acid sodium salt 10 mM buffer pH 3.0 (Solution A) and acetonitrile (Solution B) as mobile phases in gradient elution (t = 0 min, 5% B; t = 1 min, 5% B; t = 5 min, 50% B; t = 7 min, 5% B; t = 10 min, 5% B) at a flow rate of 0.5 mL/min and UV detection of 280 nm. The linearity was proven for hexoprenaline over a concentration range of 3.50–6.50 µg/mL (R2 = 0.9998). Forced degradation studies were performed by subjecting the samples to hydrolytic (acid and base), oxidative, and thermal stress conditions. Standard solution stability was also performed. The proposed validated method was successfully used for the quantitative analysis of bulk, stability and injectable dosage form samples of the desired drug product. Using the AQbD principles, it is possible to generate methodologies with enhanced knowledge, which can eventually lead to a reduced regulatory risk, high quality data and lower operational costs. 相似文献
37.
Dalibor Hodko Maria Gamboa-Aldeco Oliver J. Murphy 《Journal of Solid State Electrochemistry》2009,13(7):1063-1075
A photopolymerization process that simultaneously deposits electronically conducting polymer films and incorporates nanophase
silver grains within the films, the silver grains having been formed in situ on irradiating cast, photopolymerizable formulations
containing silver salts, was developed. Polymer films produced from formulations containing large organic anions were very
flexible and strongly adherent to substrates. Polypyrrole films containing silver grains were characterized electronically
on measuring their electronic conductivities and electrochemically on recording their cyclic voltammetric profiles. Conductivities
were affected by the chemical identity and concentration of components added to photopolymerizable formulations. The best
photopolymerized films had a conductivity of the order of 1 S cm−1. Electronically conducting films derived from formulations consisting of a monomer, an electron acceptor/“dopant,” and a
photoinitiator were electrochemically active. They possessed long-term stability under extended electrode potential cycling
conditions, acceptable charge storage capacity, and the ability to oxidize or reduce redox couples in solution.
Paper submitted for inclusion in the special issue of the Journal of Solid State Electrochemistry honouring the 85th birthday
of Professor John O’M. Bockris. 相似文献
38.
An analytical method for the determination of amitraz residues in beeswax after hydrolysis to 2,4-dimethylaniline is reported. It consists of wax extraction with an acid buffer solution, head space solid phase microextraction and GC-ITD analysis. The limit of determination is 1 ng g−1. Wax samples from beekepers and commercial foundations were analysed, content of residues varied from <1 to 20.5 ng g−1. 相似文献
39.
A new ruthenium-catalyzed direct sp3 C-H to C-C bond transformation is disclosed. Specifically, a method for the alpha-arylation of cyclic amines, containing either permanent (pyridine, pyrimidine) or removable (amidine) directing groups, is described. This cross-coupling reaction involves heating amine substrates with arylboronate ester at 150 degrees C in a ketone solvent with a catalytic amount of ruthenium carbonyl [Ru3(CO)12]. Arylboronate esters containing either electron-withdrawing or electron-donating substituents could be efficiently coupled. Heteroarene boronates were also effective donors. 相似文献
40.
Przemyslaw W. Wachulak Andrzej Bartnik Henryk Fiedorowicz Dalibor Pánek Petr Br??a 《Applied physics. B, Lasers and optics》2012,109(1):105-111
Laser-produced plasma sources of short-wavelength radiation offer an interesting alternative to synchrotron and free-electron laser installations. Recently, we reported on a newly developed desktop EUV microscope based on plasma generated from a gas-puff target and diffractive optics. The half-pitch resolution of the microscope approached 50?nm. Compared to analogous microscopes based on synchrotron sources, our system is compact and cost-effective. In this paper, we present the results of imaging experiments on a thin polycrystalline object that was carried out in order to further examine the applicability of the microscope. We have demonstrated here that EUV microscopy can provide structural information that cannot be accessed by conventional optical microscopy or SEM. 相似文献