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961.
A. A. Samokhvalov T. I. Arbuzova N. A. Viglin V. V. Osipov N. I. Solin S. V. Naumov V. G. Bamburov N. I. Lobachevskaya O. G. Reznitskikh 《Physics of the Solid State》1999,41(2):262-264
Mg1−x
CuxO solid solutions having an NaCl structure with 0⩽x⩽0.20 are synthesized and Cu-Mg1−x
CuxO structures are prepared for superconductivity studies. The magnetic susceptibility χ, electron paramagnetic resonance (EPR), and electrical conductivity of the solid solutions are studied at temperatures of
5–550 K. It is shown that χ
−1(T) obeys the Curie-Weiss law with a paramagnetic Curie temperature Θ close to zero and an effective magnetic moment μ
eff=1.9 μ
B, close to the 1.73 μ
B of a Cu2+ ion with spin S=1/2. The width ΔH of the EPR line depends weakly on temperature and increases as x is raised. The volume narrowing of the EPR linewidth ΔH is used to estimate the exchange interaction parameter, 3×10−4 eV. The g-factor is close to 2 and is temperature independent. The electrical conductivity of Mg1−x
CuxO at T=300 K is ≈10−11–10−12 Ω−1 cm−1 for x=0 and increases to 10−5–10−6 Ω−1 cm−1 for x=0.15–0.20. The conductivity is p-type. Magnetic shielding is observed in Cu-Mg1−x
CuxO structures with x=0.15 and 0.20. The possible connection of this phenomenon with interference superconductivity in the contact layer of the
structure is discussed.
Fiz. Tverd. Tela (St. Petersburg) 41, 293–296 (February 1999) 相似文献
962.
L. A. Golovan’ A. M. Zheltikov P. K. Kashkarov N. I. Koroteev M. G. Lisachenko A. N. Naumov D. A. Sidorov-Biryukov V. Yu. Timoshenko A. B. Fedotov 《JETP Letters》1999,69(4):300-305
Efficient generation of the second optical harmonic is observed experimentally in a multilayer periodic structure based on
porous silicon. The second-harmonic signal is much stronger than the signal from a uniform porous silicon layer or from the
single-crystal silicon substrate. The orientational dependence of the second-harmonic signal is isotropic. The second-harmonic
intensity as a function of the reflection angle reaches a maximum in the direction corresponding to the minimum phase detuning
in a multilayer periodic structure.
Pis’ma Zh. éksp. Teor. Fiz. 69, No. 4, 274–279 (25 February 1999)
Deceased. 相似文献
963.
We apply the tensor transfer equation for downward radio emission in a weakly anisotropic medium and a generalized analysis
of the generation conditions for such radiation to develope a unified approach to the solution of the problem on reconstruction
of the atmospheric temperature prifile over a wide altitude range (from theoustasche layer to the mesosphere) using ground-based measurements of thermal radio emission. Radio emission in the oxygen spin—rotational
band centered at the wavelength 5 mm was measured with radiometer equipment of various spectral resolutions. The capabilities
of the remote sounding are illustrated by the results of the temperature profile reconstruction in theoustasche layer and troposphere using the radiometric measurements of the atmospheric radio emission, as well as by the results of
numerical simulations of the radiometric experiment for the upper layers of the atmosphere. Trends in development of ground-based
remote sounding of the temperature are discussed.
Radiophysical Research Institute, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika,
Vol. 42, No. 1, pp. 45–59, January, 1999. 相似文献
964.
Variable temperature (−55 to −135°C) studies of the infrared spectra (3500–400 cm−1) of 1-bromo-2-fluoroethane, BrCH2CH2F, dissolved in liquid krypton and xenon have been recorded. From these data, the enthalpy difference has been determined to be 108±9 cm−1 (1.296±0.113 kJ/mol) and 112±8 cm−1 (1.346±0.098 kJ/mol) from the krypton and xenon solutions, respectively, with the trans conformer the more stable rotamer. Complete vibrational assignments are presented for both conformers which are consistent with the predicted frequencies obtained from the ab initio MP2/6-31G* calculations. The optimized geometries, conformational stabilities, harmonic force fields, infrared intensities, Raman activities, and depolarization ratios have been obtained from RHF/6-31G* and/or MP2/6-31G* ab initio calculations. These quantities are compared to the corresponding experimental quantities when appropriate. Structural parameters and conformational stability have also been obtained from MP2/6-311+G** calculations. Combining the ab initio predicted structural parameters with the microwave rotational constants, ro parameters have been obtained for the gauche conformer. 相似文献
965.
Pan
e Naumov Gligor Jovanovski Mirjana Ristova Ibrahim Abdul Razak Semiha kir Suchada Chantrapromma Hoong‐Kun Fun Seik Weng Ng 《无机化学与普通化学杂志》2002,628(13):2930-2939
Four different coordination patterns were observed following the partial or complete thermodynamically‐controlled ligand substitution of the hydrated tetraaquabis(o‐sulfobenzimidato‐N)copper(II) complex with heterocyclic bases as examined by X‐ray diffraction. The N‐heterocycle directs the o‐sulfobenzimidate (saccharinate) anion into the immediate coordination polyhedron of the metal by any of the imido, carbonyl or sulfonyl functionalities, or as a lattice counter‐ion in the crystal lattice. Aqua(o‐sulfobenzimidato‐O)tetrakis(4‐methylpyridine)copper(II) o‐sulfobenzimidate hemihydrate ( 1 ) crystallizes in the monoclinic space group P21/n [a = 14.7858(2), b = 16.9090(1), c = 26.2350(2)Å; β = 92.861(1)°], aquadi(o‐sulfobenzimidato‐N)bis(4‐propylpyridine)copper(II) ( 2 ) in the tetragonal space group P42/n [a = 15.4127(1), c = 13.4604(1)Å], diaquatetrakis(3‐(2‐propenyl)imidazole)copper(II) di‐o‐sulfobenzimidate ( 3b ) in the monoclinic space group P21/c [a = 9.3959(5), b = 28.029(2), c = 8.8763(3)Å; β = 111.175(1)°] and di(o‐sulfobenzimidato)tetra(isoquinoline)copper(II) ( 4b ) in the orthorhombic space group Pna21 [a = 23.2132(6), b = 11.5760(2), c = 17.6297(4)Å]. The copper atom in 1 is six‐coordinate in a distorted trans‐N4O2Cu octahedron with elongated copper—oxygen bonds [Cu—Owater = 2.462(3), Cu—Osulfonyl = 2.567(3)Å]. This adduct represents the first example of a combined Osulfonyl/ionic coordination of the o‐sulfobenzimidate ion in the same crystal. The copper atom in 2 is five‐coordinate in the form of a N4OCu square pyramid [Cu—Owater = 2.238(5)Å]. In 3 , the o‐sulfobenzimidate anions are linked to the copper atom through the coordinated water molecule forming a distorted octahedral N4O2Cu environment. In 4 , the copper atom is nearly octahedrally coordinated by four nitrogen atoms and a pair of o‐sulfobenzimidate carbonyl oxygen atoms. The structural details of the o‐sulfobenzimidate coordination pattern correspond well with the 298 and 77 K FT IR spectra of the adducts. The structures of two other solid adducts, tris(3‐(2‐propenyl)imidazole)copper(II) di‐o‐sulfobenzimidate trihydrate ( 3a ) and diaquabis(o‐sulfobenzimidato‐N)bis(isoquinoline)copper(II) ( 4a ) have been predicted by their spectral features. Alteration of the o‐sulfobenzimidate coordination mode upon changing the heterocycle ligand shows that this moiety is as a convenient polyfunctional structural tool for the construction of functional solids. 相似文献
966.
E. Yu. Gordeev A. K. Naumov V. V. Semashko R. Yu. Abdulsabirov L. S. Korableva 《Physics of the Solid State》2008,50(8):1477-1480
This paper reports on the results of investigations into the optical properties of the Na4Y6F22: (Ce3+, Yb3+) crystal. The technique for growing and preparing samples is briefly outlined. The instruments used for performing spectroscopic investigations and studying optical properties of samples under intense laser pumping are described. The results of the investigations performed are presented and discussed. 相似文献
967.
Viglin N. A. Tsvelikhovskaya V. M. Naumov S. V. Shorikov A. O. Pavlov T. N. 《Physics of the Solid State》2020,62(12):2301-2304
Physics of the Solid State - In a semiconductor spin device with electrodes formed from the Fe2NbSn half-metallic ferromagnet film, a spin polarization of PS = 4% of electrons injected into the... 相似文献
968.
Plastun I. L. Zakharov A. A. Naumov A. A. Zhulidin P. A. Filin P. D. 《Optics and Spectroscopy》2021,129(7):794-803
Optics and Spectroscopy - One of the promising materials for biophotonics and medicine, used for the diagnosis and targeted therapy of cancer, are silver sulfide nanoparticles. Molecular mechanisms... 相似文献
969.
Naumov I. V. Okulova N. V. Sharifullin B. R. Lomakina V. A. Okulov V. L. 《Doklady Physics》2021,66(4):118-121
Doklady Physics - The effect of nanoroughnesses on the structure of a closed vortex flow generated in a motionless vertical cylindrical container by an upper rotating disk with various roughnesses... 相似文献
970.
JETP Letters - NdBaCo2O5 + δ, $$\delta \approx 0.5$$ , layered cobaltite is a metamagnet, which at a relatively low magnetic field transforms below T ~ 20 K from the antiferromagnetic phase to... 相似文献