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11.
The theory and practical applications of very slow (antisymmetric) optical plasmons are described. These plasmons can exist
on thin metal films and filaments and (as standing waves) on metal spheres and ellipsoids. The material presented here extends
the conventional concepts of electromagnetic modes of spaces, probability of spontaneous emission, construction of optical
images, optical focusing, and the photon momentum. The reviewed achievements in this field have been obtained in the last
years. The problem of the photon momentum in a medium has been a subject of irreconcilable disputes for nearly 100 years,
beginning with Minkowski and Abraham’s famous papers. Various practical applications are considered, including experiments
with the significant enhancement of atom spontaneous emission into a plasmon field mode of a nanoparticle; experiments on
focusing optical radiation into a spot much smaller than the diffraction-limited one (the so-called almost ideal Pendry lens,
which produces an image with details much smaller than the light wavelength); and, finally, a greatly increased (by factors
of 10, 100, or more) photon momentum in plasmon. 相似文献
12.
A. G. Shipov S. V. Grüner A. A. Korlyukov E. P. Kramarova T. P. Murasheva S. Yu. Bylikin Vad. V. Negrebetskii F. A. Ivashchenko D. V. Airapetyan G. Ya. Zueva M. Yu. Antipin Yu. I. Baukov 《Russian Chemical Bulletin》2010,59(4):761-770
Reactions of GeBr4 with N,N-dimethyl-2-trimethylsiloxypropionamide (2a), (S)-2-trime-thylsiloxypropionpyrrolidide ((S)-2b), and N,N-dimethyl-O-(trimethylsilyl)mandelamide (2c) afforded pentacoordinated neutral (O,O)-monochelates, viz., N,N-dimethyl-2-tribromoger-myloxypropionamide (3a), (S)-2-tribromogermyloxypropionpyrrolidide ((S)-3b), and N,N-dimethyl-O-(tribromogermyl)mandelamide (3c), respectively. X-ray diffraction study was performed for tribromides 3a, (S)-3b, and 3c, as well as for the N,N-dimethylmandelamide (1c) described earlier. According to the X-ray diffraction data, the Ge atom in tribromides 3a, (S)-3b, and 3c is pentacoordinated and has trigonal bipyramidal configuration with two halogen atoms and oxygen atom of the ether group in the equatorial positions and the halogen atom and the amide oxygen atom in the axial fragment, the bonds in which are somewhat longer as compared to the analogous bonds in tetracoordinated Ge compounds. 相似文献
13.
Conclusions The high selectivity of the chlorination of CH3GeCl3with the formation of CH2ClGeCl3 by the action of a UV laser is independent of the emission wavelength in the range from 193 to 308 run. The quantum yield is not less than 102.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2167–2170, September, 1988. 相似文献
14.
The creation of electron-positron pairs in the collision of two heavy nuclei is considered. A systematic quantum-mechanical approach is developed for the complete electron-nuclear system. The finite size of the nuclei and the possible resonances of the superheavy compound nucleus formed from the initial nuclei are taken into account. The energetic approach known in the theory of the breakdown of quasisteady systems is generalized to the case of the collisional problem. This approach is combined with perturbation theory for the complete electron-nuclear system. The rearrangement of the negative-continuum spectrum is taken into account using the procedure of [14], which is generalized with the aim of introducing additional conditions, in particular, the condition associated with correct choice of the zero approximation. The method is the same for Z < Zcr and Z > Zcr, where Zcr is the minimum nuclear charge at which spontaneous pair creation is possible. The contribution of the spontaneous channel to the amplitude of the process is automatically taken into account.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 97–107, August, 1990. 相似文献
15.
E.?M.?Zueva E.?V.?Tretyakov S.?V.?Fokin G.?V.?Romanenko A.?O.?Tkacheva A.?S.?Bogomyakov O.?V.?Petrova B.?A.?Trofimov R.?Z.?Sagdeev V.?I.?OvcharenkoEmail author 《Russian Chemical Bulletin》2016,65(3):666-674
5-Formylpyrrolyl-substituted nitronyl and imino nitroxide radicals HL1 and HL2 were synthesized. Their solid phases are formed by packing pairs of the molecules. In the {HL1...HL1} pairs, the dominant interaction is the ferromagnetic exchange with J/kB = 8.8 K (Hamiltonian \(H = 2J\left( {\overrightarrow {{s_1}} \overrightarrow {{s_2}} } \right)\)). The ferromagnetic exchange occurs also in the heterospin molecules [Ni(L1)2], [Cu(L1)2], and [Ni(L2)2(MeOH)2]. In the complexes [Ni(L1)2] and [Cu(L1)2], a small change in the mutual orientation of the coordinated ligands has a considerable effect on the value and the sign of the energy of exchange interactions between the unpaired electrons of the metal ion and paramagnetic ligands. 相似文献
16.
The effect of a significant (by a factor of more than 107) increase in the rate of a one-photon spontaneous radiative transition is calculated for an excited atom (molecule) located near a metal (silver) nanocylinder. The atom radiates into a surface plasmon wave of the TM0 type. The TM0 wave is concentrated near the nanocylinder surface rather than spreads infinitely in space. Having a limited length, the nanocylinder efficiently radiates into free space, in contrast to the case of an infinite surface (plane or cylindrical). Under the conditions considered, the duration of the atomic dipole radiation is about a femtosecond. The situation discussed, which can be easily realized in experiments, may help in understanding the significant increase in the intensity of Raman scattering observed experimentally. 相似文献
17.
The electronic structures of polynuclear different-ligand nickel(ii) complexes [K2Ni6Piv7(hfac)3(OH)4(HPiv)2(Me2CO)2], [Ni6Piv4(hfac)4(OH)4(Me2CO)4], and [Ni8Piv10(hfac)2(OH)2(MeO)2(MeOH)2(HPiv)2] were studied within the framework of the DFT approach. For each complex, the isotropic exchange parameters for all pairs of paramagnetic centers were calculated. Based on the results obtained, models for Heisenberg-Dirac-van Vleck exchange interaction (with minimal number of parameters) were proposed, which can be used to describe the magnetic properties of the compounds under study. 相似文献
18.
19.
E. M. Zueva M. M. Petrova S. A. Borshch An. M. Kuznetsov 《Russian Chemical Bulletin》2008,57(12):2513-2519
The molecular structure and magnetic properties of alkoxy-polyoxovanadates [VIV
n
VV
6−n
O7(OR)12]4−n
(n = 4, 3, 2) were studied within the framework of the DFT approach. The equilibrium geometric configurations of all complexes
studied in this work are characterized by a distorted octahedral hexavanadate core; the unpaired d-electrons are localized
on the metal centers (VIV). The localized spin density distribution is also retained in the low-temperature crystal structures of the compounds whose
magnetic properties are described by the Heisenberg-Dirac-van Vleck exchange spin Hamiltonian. The exchange parameters calculated
using the broken symmetry formalism suggest predominance of ferromagnetic coupling between vanadium(IV) ions in the μ-OR bridged
dimeric units {VIVO(OR)VIV} and in the diagonal pairs {VIVOVIV} (n = 4). The results obtained indicate that the magnitude and sign of the exchange parameters in the isostructural dimeric units
within the hexavanadate core depend on the total number of unpaired electrons in the system. 相似文献
20.
Romanenko G. V. Fokin S. V. Bogomyakov A. S. Zueva E. M. Ovcharenko V. I. 《Journal of Structural Chemistry》2022,63(3):441-450
Journal of Structural Chemistry - The structures of Ni(II), Cu(II), and Zn(II) complexes with anions of 2,5-pyrrolyl-disubstituted nitronyl nitroxide (L1) and iminonitroxide (L2) diradicals (HL1 is... 相似文献