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111.
112.
Nucleation, growth and sintering of Pd deposited on an ultra-thin silica film were studied by scanning tunneling microscopy and infrared reflection absorption spectroscopy. No preferential nucleation of Pd on the silica surface was observed both at 90 and 300 K deposition. When adsorbed on Pd clusters formed at 90 K, CO causes a strong sintering effect even at this temperature. The results are rationalized on the basis of a high mobility of Pd carbonyl-like species on the silica film. At a given Pd coverage, the extent of CO induced sintering cannot be achieved by annealing in vacuum. In addition, vacuum sintering, which commences above 700 K, goes simultaneously with interdiffusion of Pd and support. 相似文献
113.
Focusing properties of an acoustic lens based on a modified triangular sonic crystal slab whose columns are aligned on concentric
arcs of equal radial distance are investigated. Capability of focusing normally-incident plane waves is demonstrated by means
of Finite Element Method. Focusing mechanisms are discussed on the basis of band structures and equifrequency contours considering
a model where triangular lattice is elongated along ΓK direction. Focusing behavior of the proposed lens is argued to arise
from negative refractions at the air-lens interfaces accompanied by index guiding in its interiors. Wavelength-order confinement
in the transverse direction is observed. Double focusing is attributed to geometrical effects and contribution of self guiding
is discussed. Possibility of occurrence of birefraction at the input face of the lens together with positive refraction at
the output face is also discussed. 相似文献
114.
S. Irem Kaya Ahmet Cetinkaya Mehmet G. Caglayan Sibel A. Ozkan 《Electrophoresis》2022,43(9-10):1035-1049
Biopharmaceuticals (recombinant technology-based products, vaccines, whole blood and blood components, gene therapy, cells, tissues, etc.,) are described as biological medical products produced from various living sources such as human, microbial, animal, and so on by manufacturing, extraction, or semi-synthesis. They are complex molecules having high molecular weights. For their safety and efficacy, their structural, clinical, physicochemical, and chemical features must be carefully controlled, and they must be well characterized by analytical techniques before the approval of the final product. Capillary electrophoresis (CE) having versatile modes can provide valuable safety and efficacy information, such as amino acid sequence, size variants (low and high molecular weight variants), charged variants (acidic and basic impurities), aggregates, N-linked glycosylation, and O-linked glycosylation. There are numerous applications of CE in the literature. In this review, the most significant and recent studies on the analysis of recombinant DNA technology-based products using different CE modes in the last ten years have been overviewed. It was seen that the researches mostly focus on the analysis of mAbs and IgG. In addition, in recent years, researchers have started to prefer CE combined mass spectrometry (MS) techniques to provide a more detailed characterization for protein and peptide fragments. 相似文献
115.
We study the problem of identifying unknown source terms in an inverse parabolic problem, when the overspecified (measured) data are given in form of Dirichlet boundary condition u(0,t) = h(t) and , where is an arbitrarily prescribed subregion. The main goal here is to show that the gradient of cost functional can be expressed via the solutions of the direct and corresponding adjoint problems. We prove Hölder continuity of the cost functional and derive the Lipschitz constant in the explicit form via the given data. On the basis of the obtained results, we propose a monotone iteration process. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
116.
In this paper, we study the asymptotic behaviour of weak solutions for the regularized Bénard problem. We establish the global existence and uniqueness of weak solutions of this problem and give a proof for the existence of global attractor in the three-dimensional case for this system. 相似文献
117.
Muncipinto G Kaya T Wilson JA Kumagai N Clemons PA Schreiber SL 《Organic letters》2010,12(22):5230-5233
A short and modular synthetic pathway using intramolecular 1,3-dipolar cycloaddition reactions and yielding functionalized isoxazoles, isoxazolines, and isoxazolidines is described. The change in shape of previous compounds and those in this study is quantified and compared using principal moment-of-inertia shape analysis. 相似文献
118.
F. Doğan M. Ulusoy Ö. F. Öztürk İ. Kaya B. Salih 《Journal of Thermal Analysis and Calorimetry》2009,96(1):267-276
The thermal decomposition kinetics of sterically hindered salen type ligand (L) and its metal complexes [M=Co(II), Ni(II), Cu(II)] were investigated by thermogravimetric analysis. A direct insertion probe-mass spectrometer (DIP-MS)
was used for the characterization of metal complexes of L and all fragmentations and stable ions were characterized. The thermogravimetry and differential thermogravimetry (TG-DTG)
plots of salen type salicylaldimine ligand and complexes showed a single step.
The kinetic analysis of thermogravimetric data was performed by using the invariant kinetic parameter method (IKP). The values
of the invariant activation energy, E
inv and the invariant pre-exponential factor, A
inv, were calculated by using Coats-Redfern (CR) method. The thermal stabilities and activation energies of metal complexes of
sterically hindered salen type ligand (L) were found as Co(II)>Cu(II)>Ni(II)>L and E
Cu>E
Ni>E
Co>L. Also, the probabilities of decomposition functions were investigated. The diffusion functions (D
n) are most probable for the thermal decomposition of all complexes. 相似文献
119.
Kaya K Morrison LF Codd GA Metcalf JS Sano T Takagi H Kubo T 《Molecules (Basel, Switzerland)》2006,11(7):539-548
A novel biosurfactant, 2-acyloxyethylphosphonate, was isolated from waterblooms of Aphanizomenon flos-aquae. Its structure was elucidated by chemical degradation and HRFABMS, GC/EI-MS and 1D- and 2D-NMR spectral analyses. The surfactant contained one mole of 2-hydroxyethylphosphonate and one mole of fatty acid, with hexadecanoic acid accounting for 84.1% of the total fatty acid content. The structure was confirmed by synthesis of 2-oleoyloxyethylphosphonate from ethylene oxide, phosphorus acid and oleic acid chloride. Considering the isolated surfactant molecule as hexadecanoyloxyethylphosphonic acid (mw. 364), the critical micelle concentration (CMC) was about 22 mM. 相似文献
120.
Y. Kaya 《Siberian Mathematical Journal》2006,47(3):452-458
Let f: M m → ? m+1 be an immersion of an orientable m-dimensional connected smooth manifold M without boundary and assume that ξ is a unit normal field for f. For a real number t the map f tξ: M m → ? m+1 is defined as f tξ(p) = f(p) + tξ(p). It is known that if f tξ is an immersion, then for each p ∈ M the number of the focal points on the line segment joining f(p) to f tξ(p) is a constant integer. This constant integer is called the index of the parallel immersion f tξ and clearly the index lies between 0 and m. In case f: $\mathbb{S}^m \to \mathbb{R}^{m + 1} $ is an immersion, we study the presence of a component of index μ in the push-out space Ω(f). If there exists a component with index μ = m in Ω(f) then f is known to be a strictly convex embedding of $\mathbb{S}^m $ . We reveal the structure of Ω(f) when $f(\mathbb{S}^m )$ is convex and nonconvex. We also show that the presence of a component of index μ in Ω(f) enables us to construct a continuous field of tangent planes of dimension μ on $\mathbb{S}^m $ and so we see that for certain values of μ there does not exist a component of index μ in Ω(f). 相似文献