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91.
Theoretical and Mathematical Physics - We show that a constant external magnetic field, generally speaking, is not able to prevent breaking (loss of smoothness) of relativistic plasma oscillations,... 相似文献
92.
Tuskaev V. A. Bogdanov V. S. Gagieva S. Ch. Kurmaev D. A. Shatokhin S. S. Evseeva M. D. Golubev E. K. Buzin M. I. Nikiforova G. G. Bulychev B. M. 《Russian Chemical Bulletin》2022,71(1):76-82
The catalytic activity of the systems based on titanium(iv) alkoxides (Ti(OPri)4, Ti(OPri)2(OCH(CF3)2)2, and Ti(OCH(CF3)2)4) and mixtures of alkylaluminum chlorides (Et2AlCl or Et3Al2Cl3) with dibutylmagnesium in ethylene polymerization and ethylene copolymerization with propylene and 5-ethylidene-2-norbornene was studied. Ultrahigh-molecular-weight polyethylene with the molecular weight reaching 4.9 · 106 Da was found to be formed in the homopolymerization reaction, whereas copolymerization gives ter-copolymers containing propylene (up to 35 mol.%) and 5-ethylidene-2-norbornene (4.3 mol.%) units.
相似文献93.
94.
E. L. Belokoneva A. S. Karamysheva O. V. Dimitrova A. S. Volkov 《Crystallography Reports》2018,63(5):734-737
Crystals of new indium iodate (K0.6Na0.4Ba)In[IO3]6 were prepared by the hydrothermal synthesis. The unit-cell parameters are a = 11.3984(3) Å, с = 11.3817(3) Å, sp. gr. R3?. The chemical formula of the compound was derived from the structure determination and refinement with anisotropic displacement parameters to R = 0.0284. In the structure the InO6 octahedra share vertices with six umbrella-like [IO3]–groups typical of iodates and form isolated 3?-symmetric charged \(\rm{In[IO_{3}]_6^{3-}}\) clusters. Large Ba, K, and Na cations occupy a common site on a threefold axis due to the isomorphous substitution and compensate the charge of the clusters. The new structure extends the family of the recently discovered alkali-metal and barium iodates containing Ti and Zr atoms in octahedral sites. The iodate K2Ge[IO3]6 containing Ge atoms in the centers of octahedra is the parent compound of this structural family. 相似文献
95.
S. A. Aleksandrova 《Siberian Mathematical Journal》2018,59(5):763-767
We construct a computable real function not Σ-definable in hereditarily finite superstructures over the extensions with decidable theory of the reals. 相似文献
96.
A CE instrument that can be assembled from commercially available components with minimal construction effort is described. Except for the electronic control circuitry no specially made parts are required. It is based on a flexible design of microfluidic, electropneumatic, and electronic sections and different configurations can easily be implemented. Automated injection into the capillary is performed hydrodynamically by the application of a pressure for a controlled length of time. The performance of the device was tested with a contactless conductivity detector by separating different metal ions. In addition, nine metal cations related to the quality of honey were separated in 2.3 min and four honey samples were analysed quantitatively to demonstrate the applicability of the method. 相似文献
97.
98.
Gupta M. Kulriya P. K. Kumar R. Ghumman S. S. 《Journal of Radioanalytical and Nuclear Chemistry》2020,323(3):1413-1418
Journal of Radioanalytical and Nuclear Chemistry - Zirconolite, a potential candidate for the immobilization of actinides was investigated for the induced effects of α-particles simulated... 相似文献
99.
Dr. Ran Du Dr. Jan-Ole Joswig Dr. René Hübner Lin Zhou Dr. Wei Wei Prof. Yue Hu Prof. Dr. Alexander Eychmüller 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(21):8370-8377
Noble-metal aerogels (NMAs) have drawn increasing attention because of their self-supported conductive networks, high surface areas, and numerous optically/catalytically active sites, enabling their impressive performance in diverse fields. However, the fabrication methods suffer from tedious procedures, long preparation times, unavoidable impurities, and uncontrolled multiscale structures, discouraging their developments. By utilizing the self-healing properties of noble-metal aggregates, the freezing-promoted salting-out behavior, and the ice-templating effect, a freeze–thaw method is crafted that is capable of preparing various hierarchically structured noble-metal gels within one day without extra additives. In light of their cleanliness, the multi-scale structures, and combined catalytic/optical properties, the electrocatalytic and photoelectrocatalytic performance of NMAs are demonstrated, which surpasses that of commercial noble-metal catalysts. 相似文献
100.
Fuqi Chen Rogemar Mamon Sévérien Nkurunziza 《Annals of the Institute of Statistical Mathematics》2018,70(4):807-853
Determining accurately when regime and structural changes occur in various time-series data is critical in many social and natural sciences. We develop and show further the equivalence of two consistent estimation techniques in locating the change point under the framework of a generalised version of the one-dimensional Ornstein–Uhlenbeck process. Our methods are based on the least sum of squared error and the maximum log-likelihood approaches. The case where both the existence and the location of the change point are unknown is investigated and an informational methodology is employed to address these issues. Numerical illustrations are presented to assess the methods’ performance. 相似文献