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71.
Konstantin P. Arefyev Victor I. Grafutin Evgeny P. Prokopyev Andrey M. Lider Roman S. Laptev Yury S. Bordulev 《Central European Journal of Chemistry》2014,12(12):1280-1284
This article considers the possibility of applying the positron annihilation spectroscopy method for investigating the pore space of rocks from oil-gas and methane-coal deposits. The diagnostics of the structure was performed using the method of spectrometry of angular correlation of annihilation rays (ACAR). Using the samples of porous silicon, the authors have shown the applicability of the ACAR method for determination of the average dimensions of spherical and cylindrical nanosized objects and their concentration 相似文献
72.
Alexander Bujotzek Ole Schütt Adam Nielsen Konstantin Fackeldey Marcus Weber 《Journal of mathematical chemistry》2014,52(3):781-804
Obtaining a sufficient sampling of conformational space is a common problem in molecular simulation. We present the implementation of an umbrella-like adaptive sampling approach based on function-based meshless discretization of conformational space that is compatible with state of the art molecular dynamics code and that integrates an eigenvector-based clustering approach for conformational analysis and the computation of inter-conformational transition rates. The approach is applied to three example systems, namely $n$ -pentane, alanine dipeptide, and a small synthetic host-guest system, the latter two including explicitly modeled solvent. 相似文献
73.
A wet chemical deposition method for preparing transparent conductive thin films on the base of Al-doped ZnO (AZO) nanoparticles
has been demonstrated. AZO nanoparticles with a size of 7 nm have been synthesised by a simple precipitation method in refluxed
conditions in ethanol using zinc acetate and Al-isopropylate. The presence of Al in ZnO was revealed by the EDX elemental
analysis (1.8 at.%) and UV–Vis spectroscopy (a blue shift due to Burstein–Moss effect). The obtained colloid solution with
the AZO nanoparticles was used for preparing by spin-coating thin films on glass substrates. The film demonstrated excellent
homogeneity and transparency (T > 90%) in the visible spectrum after heating at 400 °C. Its resistivity turned to be excessively high (ρ = 2.6 Ω cm) that
we ascribe to a poor charge percolation due to a high film porosity revealed by SEM observations. To improve the percolation
via reducing the porosity, a sol–gel solution was deposited “layer-by-layer” in alternation with layers derived from the AZO
colloid followed by heating. As it was shown by optical spectroscopy measurements, the density of thus prepared film was increased
more than twice leading to a significant decrease in resistivity to 1.3 × 10−2 Ω cm. 相似文献
74.
We obtain two results concerning the Feichtinger conjecture for systems of normalized reproducing kernels in the model subspace
K
Θ=H
2⊖ΘH
2 of the Hardy space H
2, where Θ is an inner function. First, we verify the Feichtinger conjecture for the kernels [(k)\tilde]ln=kln/||kln||\tilde{k}_{\lambda_{n}}=k_{\lambda_{n}}/\|k_{\lambda _{n}}\| under the assumption that sup
n
|Θ(λ
n
)|<1. Second, we prove the Feichtinger conjecture in the case where Θ is a one-component inner function, meaning that the
set {z:|Θ(z)|<ε} is connected for some ε∈(0,1). 相似文献
75.
Boaz Golany Konstantin Kogan Uriel G. Rothblum 《Journal of Optimization Theory and Applications》2011,148(2):336-363
We generalize a static two-agent location problem into dynamic, asymmetric settings. The dynamics is due to the ability of
the agents to move at limited speeds. Since each agent has its own objective (demand) function and these functions are interdependent,
decisions made by each agent may affect the performance of the other agent and thus affect the overall performance of the
system. We show that, under a broad range of system’s parameters, centralized (system-wide optimal) and non-cooperative (Nash)
behavior of the agents are characterized by a similar structure. The timing of these trajectories and the intermediate speeds
are however different. Moreover, non-cooperative agents travel more and may never rest and thus the system performance deteriorates
under decentralized decision-making. We show that a static linear reward approach, recently developed in Golany and Rothblum
(Nav. Res. Logist. 53(1):1–15, 2006), can be generalized to provide coordination of the moving agents and suggest its dynamic modification. When the reward scheme
is applied, the agents are induced to choose the system-wide optimal solution, even though they operate in a decentralized
decision-making mode. 相似文献
76.
Konstantin Yu. Fedorovskiy 《Complex Analysis and Operator Theory》2011,5(3):671-681
Several necessary and sufficient conditions on C
m
-approximability of functions on compact subsets of the complex plane by polyanalytic polynomials are obtained. The resulting
conditions for approximation are of the topological nature. 相似文献
77.
Han Bing-yuan Khoroshilov Andrey V. Tyurin Alexander V. Baranchikov Alexander E. Razumov Mikhail I. Ivanova Olga S. Gavrichev Konstantin S. Ivanov Vladimir K. 《Journal of Thermal Analysis and Calorimetry》2020,142(4):1533-1543
Journal of Thermal Analysis and Calorimetry - Thermodynamic properties (heat capacity Cp, entropy S°, enthalpy change ΔH° and reduced Gibbs energy ΔΦ°) of crystalline... 相似文献
78.
Aleksei S. Pronin Spartak S. Yarovoy Yakov M. Gayfulin Aleksey A. Ryadun Konstantin A. Brylev Denis G. Samsonenko Ilia V. Eltsov Yuri V. Mironov 《Molecules (Basel, Switzerland)》2020,25(24)
Compounds based on new cyanide cluster anions [{Mo6I8}(CN)6]2–, trans-[{Mo6I8}(CN)4(MeO)2]2– and trans-[{W6I8}(CN)2(MeO)4]2− were synthesized using mechanochemical or solvothermal synthesis. The crystal and electronic structures as well as spectroscopic properties of the anions were investigated. It was found that the new compounds exhibit red luminescence upon excitation by UV light in the solid state and solutions, as other cluster complexes based on {Mo6I8}4+ and {W6I8}4+ cores do. The compounds can be recrystallized from aqueous methanol solutions; besides this, it was shown using NMR and UV-Vis spectroscopy that anions did not undergo hydrolysis in the solutions for a long time. These facts indicate that hydrolytic stabilization of {Mo6I8} and {W6I8} cluster cores can be achieved by coordination of cyanide ligands. 相似文献
79.
Alexander A. Larin Dmitry M. Bystrov Leonid L. Fershtat Alexey A. Konnov Nina N. Makhova Konstantin A. Monogarov Dmitry B. Meerov Igor N. Melnikov Alla N. Pivkina Vitaly G. Kiselev Nikita V. Muravyev 《Molecules (Basel, Switzerland)》2020,25(24)
In the present work, we studied in detail the thermochemistry, thermal stability, mechanical sensitivity, and detonation performance for 20 nitro-, cyano-, and methyl derivatives of 1,2,5-oxadiazole-2-oxide (furoxan), along with their bis-derivatives. For all species studied, we also determined the reliable values of the gas-phase formation enthalpies using highly accurate multilevel procedures W2-F12 and/or W1-F12 in conjunction with the atomization energy approach and isodesmic reactions with the domain-based local pair natural orbital (DLPNO) modifications of the coupled-cluster techniques. Apart from this, we proposed reliable benchmark values of the formation enthalpies of furoxan and a number of its (azo)bis-derivatives. Additionally, we reported the previously unknown crystal structure of 3-cyano-4-nitrofuroxan. Among the monocyclic compounds, 3-nitro-4-cyclopropyl and dicyano derivatives of furoxan outperformed trinitrotoluene, a benchmark melt-cast explosive, exhibited decent thermal stability (decomposition temperature >200 °C) and insensitivity to mechanical stimuli while having notable volatility and low melting points. In turn, 4,4′-azobis-dicarbamoyl furoxan is proposed as a substitute of pentaerythritol tetranitrate, a benchmark brisant high explosive. Finally, the application prospects of 3,3′-azobis-dinitro furoxan, one of the most powerful energetic materials synthesized up to date, are limited due to the tremendously high mechanical sensitivity of this compound. Overall, the investigated derivatives of furoxan comprise multipurpose green energetic materials, including primary, secondary, melt-cast, low-sensitive explosives, and an energetic liquid. 相似文献
80.
Ferdinand H. Lutter Lucie Grokenberger Philipp Spieß Jeffrey M. Hammann Konstantin Karaghiosoff Paul Knochel 《Angewandte Chemie (International ed. in English)》2020,59(14):5546-5550
A combination of 10 % CoCl2 and 20 % 2,2′‐bipyridine ligands enables cross‐coupling of functionalized primary and secondary alkylzinc reagents with various (hetero)aryl halides. Couplings with 1,3‐ and 1,4‐substituted cycloalkylzinc reagents proceeded diastereoselectively leading to functionalized heterocycles with high diastereoselectivities of up to 98:2. Furthermore, alkynyl bromides react with primary and secondary alkylzinc reagents providing the alkylated alkynes. 相似文献