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1.
Viktor G. Khizhnyak Vitalii I. Korol' Alexei D. Kostenko 《Powder Metallurgy and Metal Ceramics》2003,42(11-12):644-648
Wear resistance measurements have been made with U8A steel bearing protective coatings based on the carbides of titanium, vanadium, and chromium or iron borides, for various forms of wear. The carbide and boride coatings raise the wear resistance considerably (by factors of 6-30 in accordance with the type of wear). Measurements have been made on the microhardness, microbrittleness, and adhesion of the coating to the substrate, which are effective characteristics that quite fully reflect the effects of the microhardness and state of stress, structure, and defectiveness on the wear resistance. 相似文献
2.
I A Bukaeva L A Iakovleva B A Lapin L V Indzhiia E M Kobe 《Eksperimental?nai?a onkologii?a》1987,9(4):26-30
The results of morphological study of B- and T-cellular immunoblast baboon lymphomas are presented. Differences are found both in the structure of tumour cells and in the histostructure of tumours as a whole. The tumor cells of B-immunoblastic lymphomas expressed mainly IgM. The tumour cells of certain T-immunoblastic lymphomas being investigated by means of monoclonal OKT4 antibodies had a surface phenotype peculiar to T-helper cells. 相似文献
3.
Alexei Manso Corrêa Machado 《Journal of Mathematical Imaging and Vision》2007,29(2-3):107-117
We present a novel method for correcting the significance level of hypothesis testing that requires multiple comparisons. It is based on the spectral graph theory, in which the variables are seen as the vertices of a complete undirected graph and the correlation matrix as the adjacency matrix that weights its edges. The method increases the statistical power of the analysis by refuting the assumption of independence among variables, while keeping the probability of false positives low. By computing the eigenvalues of the correlation matrix, it is possible to obtain valuable information about the dependence levels among the variables of the problem, so that the effective number of independent variables can be estimated. The method is compared to other available models and its effectiveness illustrated in case studies involving high-dimensional sets of variables. 相似文献
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Hiroyuki Miki Takanori Takeno Toshiyuki Takagi Alexei Bozhko Mikhail Shupegin Hideya Onodera Takao Komiyama Takashi Aoyama 《Diamond and Related Materials》2006,15(11-12):1898
Superconductivity in a tungsten-containing carbon-oxide film was reported. The film with 500 nm thickness was deposited onto polycrystalline silicon oxides using chemical vapor deposition and the co-sputtering of a tungsten metal target. The bonding state of the carbon atoms and the macroscopic and microscopic crystal structure of the film were investigated by Raman spectroscopy, X-ray diffraction and transmission electron microscopy measurements. From the experimental results, we determined that this film essentially had an amorphous structure. The temperature dependence on resistivity was measured in the temperature range of 2–300 K. Resistive superconducting transition was observed at 3.8 K. The dc magnetizations were measured in the temperature range of 1.8–6.5 K. The diamagnetism resulting from a superconductive state was observed below 3.75 K, which is consistent with a resistive superconducting transition. It is thought that the finite sized clusters of the different superconductive transition temperatures cooperatively produce a macroscopic superconducting phenomenon. 相似文献
7.
G. G. Lapin A. D. Shargorodskii 《Power Technology and Engineering (formerly Hydrotechnical Construction)》1992,26(6):348-352
The article is written on the basis of the authors' generalization of the experience of constructing pumped storage stations abroad during 1960–1990 from materials of articles in Soviet and foreign journals, scientific and technical publications, current information Hydropower Abroad, etc. (in all, 239 sources). 相似文献
8.
Alsu Z. Malikova Anastasia S. Shcherbakova Konstantin A. Konduktorov Anastasia S. Zemskaya Alexandra A. Dalina Vladimir I. Popenko Olga G. Leonova Alexei V. Morozov Nikolay N. Kurochkin Olga A. Smirnova Sergey N. Kochetkov Maxim V. Kozlov 《International journal of molecular sciences》2021,22(9)
Recent evidence suggests that fibrotic liver injury in patients with chronic hepatitis C correlates with cellular senescence in damaged liver tissue. However, it is still unclear how senescence can affect replication of the hepatitis C virus (HCV). In this work, we report that an inhibitor of cyclin-dependent kinases 4/6, palbociclib, not only induced in hepatoma cells a pre-senescent cellular phenotype, including G1 arrest in the cell cycle, but also accelerated viral replicon multiplication. Importantly, suppression of HCV replication by direct acting antivirals (DAAs) was barely affected by pre-senescence induction, and vice versa, the antiviral activities of host-targeting agents (HTAs), such as inhibitors of human histone deacetylases (HDACi), produced a wide range of reactions—from a dramatic reduction to a noticeable increase. It is very likely that under conditions of the G1 arrest in the cell cycle, HDACi exhibit their actual antiviral potency, since their inherent anticancer activity that complicates the interpretation of test results is minimized. 相似文献
9.
A flow cell was used for the in situ ESR monitoring of the state and reactivity of chromium ions in Cr-ZSM-5. Calcination of Cr(NO3)3/NH4-ZSM-5 in air at 500°C is accompanied by migration of chromium ions inside the zeolitic channels and stabilization ofisolated Cr5+ cations near lattice A13+ ions. Calcination of Cr-ZSM-5 at 750°C leads to a gradual disappearance of the isolated Cr5+ cations and formation of -Cr2O3 microcrystals. All the Cr5+ cations are accessible to gas-phase molecules: O2 strongly broadens the dipole-dipole signal; H2O sorption increases the local crystal field symmetry; admission of CCl4 results in a small change of the Cr5+ local coordination; strongly stabilized complexes on Cr-ZSM-5 are observed upon sorption of either NO or NO2. The sorption of C2H6 on Cr-ZSM-5 at 20°C is accompanied by a gradual reduction of the Cr5+ sites. At 500°C in [C3H6 + O2 + He] flow, even at a large excess of oxidant, the reduction of a noticeable part of Cr5+ ions takes place. At 400°C, in the same gas mixtures, a deeper reduction of Cr5+ occurs. Closer to stoichiometric conditions, in a [C3H6 + NO + He] flow with 120% excess of oxidant the Cr5+ is completely reduced at 500°C. The oxidation of propene is accompanied by coke deposition on the surface of the catalyst. The implications of the results are discussed. 相似文献
10.
A theory of chromatography of eight-shaped, trefoil-shaped and daisy-like polymers is developed. For a model of an ideal chain in a slit-like pore exact equations and a number of approximate formulae for the distribution coefficient K of these polymers are derived. All modes of chromatography of complex macrocycles of arbitrary molar mass in both narrow and wide pores are covered by the theory. It is shown that complex macrocycles always elute after linear polymers and rings of the same contour length. The effective chromatographic radius of eight-shaped and daisy-like macromolecules, which determines retention in size-exclusion chromatography are calculated. The increase in the retention with molar mass is predicted for all types of macrocycles at the critical interaction condition. Non-monotonous molar mass dependences of K are found at pre-critical interaction. We simulate separation of complex cyclic polymers from linear and ring precursors, discuss possibilities to separate symmetric and asymmetric eights, and speculates on the use of chromatography for separating knotted and unknotted polymer rings. According to the theory, the chromatography under the critical and pre-critical interaction conditions is expected to be especially efficient in these and similar problems. Boundary conditions for the theory and its applicability to real systems are discussed. 相似文献