排序方式: 共有96条查询结果,搜索用时 390 毫秒
1.
Daniil A. Boiko Evgeniy O. Pentsak Vera A. Cherepanova Evgeniy G. Gordeev Valentine P. Ananikov 《Chemical science》2021,12(21):7428
Smoothness/defectiveness of the carbon material surface is a key issue for many applications, spanning from electronics to reinforced materials, adsorbents and catalysis. Several surface defects cannot be observed with conventional analytic techniques, thus requiring the development of a new imaging approach. Here, we evaluate a convenient method for mapping such “hidden” defects on the surface of carbon materials using 1–5 nm metal nanoparticles as markers. A direct relationship between the presence of defects and the ordering of nanoparticles was studied experimentally and modeled using quantum chemistry calculations and Monte Carlo simulations. An automated pipeline for analyzing microscopic images is described: the degree of smoothness of experimental images was determined by a classification neural network, and then the images were searched for specific types of defects using a segmentation neural network. An informative set of features was generated from both networks: high-dimensional embeddings of image patches and statics of defect distribution.Defectiveness of carbon material surface is a key issue for many applications. Pd-nanoparticle SEM imaging was used to highlight “hidden” defects and analyzed by neural networks to solve order/disorder classification and defect segmentation tasks. 相似文献
2.
Tanskanen H Khriachtchev L Räsänen M Feldman VI Sukhov FF Orlov AY Tyurin DA 《The Journal of chemical physics》2005,123(6):64318
Vinyl radicals produced by annealing-induced reaction of mobilized hydrogen atoms with acetylene molecules in solid noble-gas matrices (Ar, Kr, and Xe) were characterized by Fourier transform infrared and electron paramagnetic resonance (EPR) spectroscopies. The hydrogen atoms were generated from acetylene by UV photolysis or fast electron irradiation. Two vibrational modes of the vinyl radical (nu7 and nu5) were assigned in IR absorption studies. The assignment is based on data for various isotopic substitutions (D and 13C) and confirmed by comparison with the EPR measurements and density-functional theory calculations. The data on the nu7 mode is in agreement with previous experimental and theoretical results whereas the nu5 frequency agrees well with the computational data but conflicts with the gas-phase IR emission results. 相似文献
3.
Litak Grzegorz Margielewicz Jerzy Gąska Damian Yurchenko Daniil Dąbek Krzysztof 《Nonlinear dynamics》2020,102(4):2125-2142
Nonlinear Dynamics - This paper examines the oscillations of a spherical pendulum with horizontal Lissajous excitation. The pendulum has two degrees of freedom: a rotational angle defined in the... 相似文献
4.
Roman V. Tominov Zakhar E. Vakulov Vadim I. Avilov Daniil A. Khakhulin Nikita V. Polupanov Vladimir A. Smirnov Oleg A. Ageev 《Molecules (Basel, Switzerland)》2021,26(1)
We have experimentally studied the influence of pulsed laser deposition parameters on the morphological and electrophysical parameters of vanadium oxide films. It is shown that an increase in the number of laser pulses from 10,000 to 60,000 and an oxygen pressure from 3 × 10−4 Torr to 3 × 10−2 Torr makes it possible to form vanadium oxide films with a thickness from 22.3 ± 4.4 nm to 131.7 ± 14.4 nm, a surface roughness from 7.8 ± 1.1 nm to 37.1 ± 11.2 nm, electron concentration from (0.32 ± 0.07) × 1017 cm−3 to (42.64 ± 4.46) × 1017 cm−3, electron mobility from 0.25 ± 0.03 cm2/(V·s) to 7.12 ± 1.32 cm2/(V·s), and resistivity from 6.32 ± 2.21 Ω·cm to 723.74 ± 89.21 Ω·cm. The regimes at which vanadium oxide films with a thickness of 22.3 ± 4.4 nm, a roughness of 7.8 ± 1.1 nm, and a resistivity of 6.32 ± 2.21 Ω·cm are obtained for their potential use in the fabrication of ReRAM neuromorphic systems. It is shown that a 22.3 ± 4.4 nm thick vanadium oxide film has the bipolar effect of resistive switching. The resistance in the high state was (89.42 ± 32.37) × 106 Ω, the resistance in the low state was equal to (6.34 ± 2.34) × 103 Ω, and the ratio RHRS/RLRS was about 14,104. The results can be used in the manufacture of a new generation of micro- and nanoelectronics elements to create ReRAM of neuromorphic systems based on vanadium oxide thin films. 相似文献
5.
Yuriy A. Zhabanov Alexey V. Eroshin Igor V. Ryzhov Ilya A. Kuzmin Daniil N. Finogenov Pavel A. Stuzhin 《Molecules (Basel, Switzerland)》2021,26(10)
The Knudsen effusion method with mass spectrometric control of the vapor composition was used to study the possibility of a congruent transition to the gas phase and to estimate the enthalpy of sublimation of metal-free tetrakis(1,2,5-thiadiazolo)porphyrazine and its nickel complex (H2TTDPz and NiTTDPz, respectively). The geometrical and electronic structure of H2TTDPz and NiTTDPz in ground and low-lying excited electronic states were determined by DFT calculations. The electronic structure of NiTTDPz was studied by the complete active space (CASSCF) method, following accounting dynamic correlation by multiconfigurational quasi-degenerate second-order perturbation theory (MCQDPT2). A geometrical structure of D2h and D4h symmetry was obtained for H2TTDPz and NiTTDPz, respectively. According to data obtained by the MCQDPT2 method, the nickel complex possesses the ground state 1A1g, and the wave function of the ground state has the form of a single determinant. Electronic absorption and vibrational (IR and resonance Raman) spectra of H2TTDPz and NiTTDPz were studied experimentally and simulated theoretically. 相似文献
6.
Stanislav I. Pekov Evgeny S. Zhvansky Vasily A. Eliferov Anatoly A. Sorokin Daniil G. Ivanov Eugene N. Nikolaev Igor A. Popov 《Molecules (Basel, Switzerland)》2022,27(8)
Ex-vivo molecular profiling has recently emerged as a promising method for intraoperative tissue identification, especially in neurosurgery. The short-term storage of resected samples at room temperature is proposed to have negligible influence on the lipid molecular profiles. However, a detailed investigation of short-term molecular profile stability is required to implement molecular profiling in a clinic. This study evaluates the effect of storage media, temperature, and washing solution to determine conditions that provide stable and reproducible molecular profiles, with the help of ambient ionization mass spectrometry using rat cerebral cortex as model brain tissue samples. Utilizing normal saline for sample storage and washing media shows a positive effect on the reproducibility of the spectra; however, the refrigeration shows a negligible effect on the spectral similarity. Thus, it was demonstrated that up to hour-long storage in normal saline, even at room temperature, ensures the acquisition of representative molecular profiles using ambient ionization mass spectrometry. 相似文献
7.
Daniil Ryabko 《Journal of Theoretical Probability》2010,23(2):565-575
Two series of binary observations x
1,x
1,… and y
1,y
2,… are presented: x
n
and y
n
are given at each time n∈ℕ. It is assumed that the sequences are generated independently of each other by two B-processes. The question of interest
is whether the sequences represent a typical realization of two different processes or of the same one. It is demonstrated
that this is impossible to decide, in the sense that every discrimination procedure is bound to err with non-negligible frequency
when presented with sequences from some B-processes. This contrasts with earlier positive results on B-processes, in particular, those showing that there are consistent
[`(d)]\bar{d}
-distance estimates for this class of processes, and on ergodic processes, in particular, those establishing consistent change
point estimates. 相似文献
8.
The universal enveloping C
*-algebra A
of twisted canonical commutation relations is considered. It is shown that, for any (–1,1), the C
*-algebra A
is isomorphic to the C
*-algebra A
0 generated by partial isometries t
i
,t
i
*,i=1,¨,d satisfying the relations
t
i
*
t
j
=
ij
(1–
k<i
t
k
t
k
*), t
j
t
i
=0, ij
and it is proved that the Fock representation of A
is faithful. 相似文献
9.
The
-algebras A{q
i}, generated by generalised quon commutation relations are considered. The nuclearity of these algebras is proved. It is shown that A{q
i}, is isomorphic to the extension of a higher-dimensional noncommutative torus. Irreducible representations of A{q
i}, are considered. It is shown that the Fock representation is faithful. 相似文献
10.