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61.
Maricel Agop Stefan Andrei Irimiciuc Adrian Ghenadi Luminita Bibire Stefan Toma Tudor-Cristian Petrescu Dorin Vaideanu Cristina Marcela Rusu Alina Gavrilut Decebal Vasincu 《Entropy (Basel, Switzerland)》2021,23(2)
In the framework of the multifractal hydrodynamic model, the correlations informational entropy–cross-entropy manages attractive and repulsive interactions through a multifractal specific potential. The classical dynamics associated with them imply Hubble-type effects, Galilei-type effects, and dependences of interaction constants with multifractal degrees at various scale resolutions, while the insertion of the relativistic amendments in the same dynamics imply multifractal transformations of a generalized Lorentz-type, multifractal metrics invariant to these transformations, and an estimation of the dimension of the multifractal Universe. In such a context, some correspondences with standard cosmologies are analyzed. Since the same types of interactions can also be obtained as harmonics mapping between the usual space and the hyperbolic plane, two measures with uniform and non-uniform temporal flows become functional, temporal measures analogous with Milne’s temporal measures in a more general manner. This work furthers the analysis published recently by our group in “Towards Interactions through Information in a Multifractal Paradigm”. 相似文献
62.
Tomaž Klinc 《Communications in Mathematical Physics》1975,41(3):273-279
It is shown that the set of Case's eigenfunctions of the one speed transport equation is complete in the rigged Hilbert spaceW 2 1 ([?1, 1])?L 2(?1, 1)?W 2 ?1 ([?1, 1]). 相似文献
63.
In the presence of 0.5-1 mol % of FeCl(3) with lithium bromide as a crucial additive, alkynyl Grignard reagents, prepared from the corresponding alkynes and methylmagnesium bromide, react with alkenyl bromides or triflates to give the corresponding conjugated enynes in high to excellent yields. The reaction shows wide applicability to various terminal alkynes and alkenyl electrophiles. 相似文献
64.
Some novel 1,2‐fused 5H‐chromeno[4,3‐b]pyridin‐5‐ones ( 5a,b ) and a 6H‐benzo[h][1,6]naphthyridin‐5‐one ( 5c ) have been synthesized starting from the 4‐chlorocoumarin‐3‐carbaldehyde ( 1a ) or its N‐methyl‐2‐quinolone analogue ( 1b ) via subsequent Knoevenagel condensation and ring closure reaction known as the ‘tert‐amino effect’. These are rare examples of the tert‐amino effect occurring at 2‐pyrone and 2‐pyridone ring. An unusual intramolecular redox reaction of the iminium ion 6 , reported earlier, most probably follows analogous mechanism as the tert‐amino effect reactions leading to 5 . 相似文献
65.
66.
Santos SF Santos ML Almeida LE Costa NB Gimenez IF Araki K Mayer I Engelmann FM Toma HE Barreto LS 《Journal of colloid and interface science》2007,305(2):264-269
In this work silica gels have been prepared by a sol-gel method using tetraethylorthosilicate as gel precursor. The tetraruthenated porphyrins H2(3-TRPyP), Co(3-TRPyP), and H2(4-TRPyP) were incorporated into the systems during gel formation without problems commonly found in the process, such as aggregation. Spectroscopic studies of the resulting silica gels revealed the presence of absorption bands in the range 200-400 nm associated with the transitions of the groups ruthenium-bipyridine, along with the Soret band at the same wavelengths observed in solution. The porphyrins were found to preserve fluorescence emission properties in the range 650-700 nm even after the aging period. Study of the thermal behavior and decomposition kinetics evidenced that the porphyrin H2(4-TRPyP) is the least stable of the group and that all compounds decompose according to first-order kinetics. 相似文献
67.
Toma LM Lescouëzec R Uriel S Llusar R Ruiz-Pérez C Vaissermann J Lloret F Julve M 《Dalton transactions (Cambridge, England : 2003)》2007,(33):3690-3698
The low-spin iron(III) complex AsPh(4)[Fe(III)(bpy)(CN)(4)].CH(3)CN (1) [AsPh(4) = tetraphenylarsonium cation] and the heterobimetallic chains [{Fe(III)(L)(CN)(4)}(2)Ni(II)(H(2)O)(2)].4H(2)O with L = bpy (2) and phen (3) [bpy = 2,2'-bipyridine and phen = 1,10-phenanthroline] have been prepared and their structures determined by X-ray diffraction methods. The structure of 1 consists of mononuclear [Fe(bpy)(CN)(4)](-) anions, tetraphenylarsonium cations and acetonitrile molecules of crystallization. The iron(III) is hexacoordinated with two nitrogen atoms of the bidentate bpy and four carbon atoms of four terminal cyanide groups building a distorted octahedral surrounding around the metal atom. 2 and 3 are isomorphous compounds whose structure is made up of neutral 4,2-ribbon like bimetallic chains of formula [{Fe(III)(L)(CN)(4)}(2)Ni(II)(H(2)O)(2)] where the [Fe(III)(L)(CN)(4)](-) unit acts as a bis-monodentate bridging ligand toward the trans-diaquanickel(II) units through two of its four cyanide groups in cis positions. The chains exhibit two orientations in the unit cell and they interact with each other through hydrogen bonds involving the coordination and crystallization water molecules together with the uncoordinated cyanide nitrogen atoms of the [Fe(L)(CN)(4)](-) units. Compounds 2 and 3 behave as ferromagnetic Fe(III)(2)Ni(II) chains which interact ferromagnetically at very low temperatures in the case of 2, whereas metamagnetic-like behaviour is observed for with a critical field (H(c)) around 200 G. For H > H(c) the ferromagnetic Fe(III)(2)Ni(II) chains of 3 exhibit a frequency dependence of the out-of-phase ac susceptibility signal at T < 3.5 K. 相似文献
68.
Shinobu Koda Masaki Miyamoto Maricela Toma Tatsuro Matsuoka Masahiro Maebayashi 《Ultrasonics sonochemistry》2009,16(5):655-659
This paper shows a systematic study of the 500 kHz frequency ultrasound efficiency on the microbial inactivation as a function of ultrasonic power delivered into the bacterial suspension. The inactivation of Escherichia coli IAM 12058, a Gram-negative bacterium and Streptococcus mutans JCM 5175, a Gram-positive bacterium is enhanced by increasing the ultrasonic power in the range of 1.7–12.4 W and the logarithm of survival ratio decreases linearly with irradiation time, except for E. coli sonicated with the highest power level. The rate constants were estimated in the linear region of the plots representing survival ratio logarithm vs. sonication time. A better understanding of the inactivation process at 500 kHz could be gained by suppressing the chemical effects with a radical scavenger. We find out that the rate constants increase with the ultrasonic power delivered into the solution and dramatically decrease by the addition of t-butanol as a radical scavenger to the bacterial suspension. For comparison, experiments were carried out at a low frequency level of 20 kHz. It was found out that for the same ultrasonic power delivered into the bacterial suspension, the inactivation was slightly enhanced at 500 kHz frequency. The examinations of bacterium performed with a TEM revealed lethal damages arising from the interaction of bacterial cells with the cavitational bubbles. A significant amount of empty cell envelopes as well as their cytoplasmatic content was detected. Thus, based on these new data, the mechanism of bacterial inactivation by ultrasounds at high frequency is discussed here. 相似文献
69.
Károly Lázár Andjelka Toma?evi? Goran Bo?kovi? Ern? Kiss 《Hyperfine Interactions》2009,192(1-3):23-29
Catalytic performances of Fe-AlPILC (14 wt.% Fe) and Fe-ZSM-5 (5 wt.% Fe) catalysts are compared in the wet oxidative degradation of methomyl. Fe-ZSM-5 exhibits outstanding whereas Fe-AlPILC shows only mediocre activity. Positions of iron are analysed in the two catalysts by Mössbauer spectroscopy. Iron is in highly dispersed state in Fe-AlPILC whereas in the other case a hematite/ZSM-5 composite is formed. The catalytic activity is attributed to iron located and stabilized in ionic dispersion. 相似文献
70.
C. Cristache K. Gméling O. Culicov M. V. Frontasyeva M. Toma O. G. Duliu 《Journal of Radioanalytical and Nuclear Chemistry》2009,279(1):7-12
A comparative study performed by means of both epithermal neutron activation analysis (ENAA) and prompt gamma neutron activation
analysis (PGAA) concerning the distribution of 9 elements (Na, Al, Cl, K, Ca, Ti, Mn Fe and Sm) in unconsolidated sediments
collected from the Black Sea anoxic region is presented. Principal component analysis (PCA) was used as a supplementary method
in interpreting experimental data. The final results have shown that eight of them (Na, Al, Cl, K, Ti, Mn, Fe and Sm) have
concentrations which differ by less than 30% from the corresponding concentrations of Upper Continental Crust (UCC), confirming
the continental origin of sediments. At the same time, Ca concentration was about six times higher than that of UCC, this
significant enrichment being due to the presence of the neighbouring oxygenated zone of considerable deposits of shell debris,
characteristic of the Western Black Sea Continental Platform. Excepting Na and Mn, the concentrations of all other elements
involved in this intercomparison were coincident within one standard deviation which attests the accuracy of this test. At
the same time, PCA revealed the presence of five clusters, which could be put into concordance with the mineralogical composition
of sediments, each of them consisting in equal proportions of elements determined by both methods. 相似文献