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31.
Surface Brillouin spectroscopy (SBS) has been widely used for elastic property characterization of thin films. For films thicker than 500 nm, however, the wavelength of surface acoustic wave in the frequency range available for SBS is smaller than film thickness, and the SBS measures only the Rayleigh wave of the film. The laser-SAW technique, on the other hand, measures only the low-frequency portion of the surface acoustic wave dispersion and can estimate only one elastic modulus of the film (typically Young's modulus). In this work, we have combined the two methods to determine both Young's modulus and Poisson's ratio of a diamond-like carbon (DLC) film. It was found that reasonable estimates can be obtained for the longitudinal wave velocity, shear wave velocity, and Young's modulus of the film. The Poisson's ratio, however, still has a relatively large measurement error. 相似文献
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33.
N. P. Berezina N. A. Kononenko A. N. Filippov S. A. Shkirskaya I. V. Falina A. A. -R. Sycheva 《Russian Journal of Electrochemistry》2010,46(5):485-493
The method of template synthesis is used for the surface modification of MF-4SK membranes with polyaniline. The influence
of the time of polyaniline synthesis in the surface layer of a perfluorinated MF-4SK membrane on its morphology and electrotransport
properties is investigated. It is established that under the synthesis conditions, a gradient distribution of polyaniline
develops across the thickness of the membrane, and as a result of this, an anisotropic composite structure is formed. It is
shown that the specific electrical conductivity and the electroosmotic and diffusion permeability exhibit an extremal character
as functions of the time of polyaniline synthesis. When the orientation of these composite membranes is changed with respect
to electrolyte flow, an asymmetry effect in their diffusion characteristics is found. With the application of the bilayer
fine porous membrane model, the modified-layer thickness is estimated, and the determining influence of the difference in
absolute values of effective fixed-charge volume densities on the development of the asymmetry effect is found. 相似文献
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Chichagov Yu. V. Bogdanov A. A. Lebedev D. S. Kogan V. T. Tubol’tsev Yu. V. Kozlenok A. V. Moroshkin V. S. Berezina A. V. 《Technical Physics》2017,62(1):144-151
Technical Physics - The electronic systems of a small high-sensitivity static mass spectrometer and software and hardware tools, which allow one to determine trace concentrations of gases and... 相似文献
36.
Buma Abramovitz Miryam Berezina Abraham Berman 《International Journal of Mathematical Education in Science & Technology》2013,44(4):428-437
This note discusses some of the shortcomings of multiple choice tests in Mathematics given to undergraduate engineering students. Examples are presented, where the disadvantages of a multiple choice test are pointed out and suggestions how to overcome the difficulties are given. 相似文献
37.
Camila Ramalho Bonturi Bruno Ramos Salu Camila Nimri Bonazza Rita de Cassia Sinigaglia Tiago Rodrigues Miryam Paola Alvarez-Flores Ana Marisa Chudzinski-Tavassi Maria Luiza Vilela Oliva 《Molecules (Basel, Switzerland)》2022,27(9)
Cell adhesion and migration are crucial for cancer progression and malignancy. Drugs available for the treatment of metastatic melanoma are expensive and unfit for certain patients. Therefore, there is still a need to identify new drugs that block tumor cell development. We investigated the effects of Enterolobium contortisiliquum trypsin inhibitor (EcTI), a protease inhibitor, on cell viability, cell migration, invasion, cell adhesion, and cell death (hallmarks of cancer) in vitro using human melanoma cells (SK-MEL-28 and CHL-1). Although EcTI did not affect non-tumor cells, it significantly inhibited the proliferation, migration, invasion, and adhesion of melanoma cells. Investigation of the underlying mechanisms revealed that EcTI triggered apoptosis and nuclear shrinkage, increased PI uptake, activated effector caspases-3/7, and produced reactive oxygen species (ROS). Furthermore, EcTI disrupted the mitochondrial membrane potential, altered calcium homeostasis, and modified proteins associated with survival and apoptosis/autophagy regulation. Acridine orange staining indicated acidic vesicular organelle formation upon EcTI treatment, demonstrating a cell death display. Electronic microscopy corroborated the apoptotic pattern by allowing the visualization of apoptotic bodies, mitochondrial cristae disorganization, and autophagic vesicles. Taken together, these results provide new insights into the anti-cancer properties of the natural EcTI protein, establishing it as a promising new therapeutic drug for use in melanoma treatment. 相似文献
38.
M. B. Berezin N. M. Berezina A. S. Semeikin A. I. V’yugin 《Russian Journal of General Chemistry》2007,77(11):1955-1958
Quaternized tetra(4-pyridyl)porphine derivatives: tetra(N-carboxymethyl-4-pyridyl)porphine tetrachloride, tetra(N-carboxymethyl-4-pyridyl)porphine tetrabromide, tetra(N-methyl-4-pyridyl)porphine tetraiodide, and tetra(N-ethoxycarbonylmethyl-4-pyridyl)porphine tetrachloride, were synthesized, isolated, and purified. The enthalpies of solution of these compounds in water at 298.15 K were determined calorimetrically. The effect of functional substituents in porphyrin ligands on the enthalpies of solution is discussed. 相似文献
39.
Alpatova N. M. Ovsyannikova E. V. Topolev V. V. Tomilova L. G. Kogan E. G. Berezina N. P. Bobrova L. P. Timofeev S. V. 《Russian Journal of Electrochemistry》2001,37(5):443-447
Anodic polymerization of aluminum tetraaminophthalocyanine chloride on conducting glasses in dimethyl formamide containing Bu4NBF4and the effect of cation exchanger MF4-SK on this process are studied. The polymer accumulation, monitored from optical absorption spectra, shows that introducing MF4-SK into solution or depositing it as a solid layer on the electrode accelerates the polymerization by a factor of four to six. 相似文献
40.