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101.
I. Bikchantaev Yu. Galyametdinov A. Prosvirin K. Griesar E. A. Soto-bustamante W. Haase 《Liquid crystals》1995,18(2):231-237
The behaviour of a large number of paramagnetic metallo-mesogenic molecules with Cu and VO in different mesophases in a magnetic field was investigated by EPR techniques and magnetic susceptibility measurements. The investigation of the angular dependence of the EPR spectra enabled conclusions to be reached concerning the molecular orientation in the external magnetic field. Temperature dependence magnetic susceptibility measurements were carried out in order to obtain information about the overall susceptibility anisotropy. The good agreement between experimental results and calculated data based on the known increment scheme is obvious. It is shown that the direction of orientation of the molecules in a magnetic field is predetermined by the sum of the anisotropy of the phenyl ring and the chelate core in the molecular structure. 相似文献
102.
Chesnokov V. V. Prosvirin I. P. Zaitseva N. A. Zaikovskii V. I. Molchanov V. V. 《Kinetics and Catalysis》2002,43(6):838-846
The state of highly dispersed palladium particles supported on filamentous carbon was studied using high-resolution electron microscopy, XPS, and X-ray diffraction analysis. Three types of filamentous carbon were used, in which the basal planes of graphite were arranged along, across, and at an angle to the nanofiber axis. The amount of supported palladium was 0.25–5.8 wt %. The structure of the carbon support was found to affect the properties of the active component. Highly dispersed palladium particles exhibited the strongest interaction with a carbon surface formed by the butt ends of graphite (002) layers. This interaction resulted in electron transfer from the metal to the support and in the stabilization of palladium in the most dispersed state. A change in the properties of palladium particles caused a change in the catalytic properties of Pd/C catalysts in the reaction of selective 1,3-butadiene hydrogenation to butenes. The strong interaction of Pd2+ with the butt ends of graphite resulted in the stabilization of palladium in an ionic state. An increase in the fraction of Pd2+ in the catalysts was responsible for a decrease in both the overall activity and selectivity of Pd/C catalysts in the reaction of 1,3-butadiene hydrogenation to butenes. 相似文献
103.
M. V. Eremin S. I. Nikitin N. I. Silkin S. Yu. Prosvirin R. V. Yusupov 《Journal of Experimental and Theoretical Physics》1998,87(4):771-775
Studies involving the piezospectroscopy method have shown that the symmetry of the pair centers of Cr3+-Cr2+ ions in the KZnF3 crystal is tetragonal. In this paper we develop a microscopic model of a pair center. We use the temperature dependence of
the integrated intensity of the absorption line to find the effective hopping integral for an e
g electron, t
σσ=205 ± 10 cm−1, and the polaron reduction factor, equal to 0.11. By analyzing the selection rules for exchange-induced electric dipole transitions
under double-exchange conditions we identify all the absorption lines of Cr3+-Cr2+ pairs.
Zh. éksp. Teor. Fiz. 114, 1421–1429 (October 1998) 相似文献
104.
Yu. V. Larichev I. P. Prosvirin D. A. Shlyapin N. B. Shitova P. G. Tsyrul’nikov V. I. Bukhtiyarov 《Kinetics and Catalysis》2005,46(4):597-602
The nature of surface cesium compounds in cesium-modified ruthenium-Sibunit catalysts for ammonia synthesis was studied by X-ray photoelectron spectroscopy (XPS). It was found that, on the reduction of promoted catalysts, cesium was incorporated into the micropores of Sibunit to form quasi-intercalation cesium-carbon bonds. In this case, the chemical state of cesium was close to its state in cesium suboxides. The subsequent interaction with atmospheric oxygen resulted in the oxidation of cesium, which occurred as cesium peroxide and cesium superoxide in the oxidized samples. Ruthenium occurred in a metallic state in the reduced samples. The activity of a Ru-Cs+/C(1) sample was higher than that of inactive Ru-Cs+/C(2). This is a consequence of the higher surface concentration of ruthenium, which is most likely due to an increase in the dispersity of metal particles, as well as of the higher probability of the interaction between the promoter and the active component due to a symbatic increase in the surface concentrations of both ruthenium and cesium.__________Translated from Kinetika i Kataliz, Vol. 46, No. 4, 2005, pp. 635–641.Original Russian Text Copyright © 2005 by Larichev, Prosvirin, Shlyapin, Shitova, Tsyrul’nikov, Bukhtiyarov. 相似文献
105.
A series of new heteronuclear complexes of a ferrocene-containing Schiffs base (LH) with NiII, PdII, VIVO, and FeIII as the central atoms has been obtained. PdL2, VOL2 FeL2Cl, and [FeL2]2O complexes manifest liquid-crystalline properties and NiL2 is nonmesomorphic. The structures of the complexes synthesized have been established by magnetic measurements and IR and ESR spectroscopy. All of them except PdL2 are paramagnetic. The antiferromagnetic exchange interactions have been observed in the FeIII complexes. The correlation of liquid-crystalline properties with the geometry of the chelate centers is discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 941–945, May, 1994. 相似文献
106.
Zhao H Berlinguette CP Bacsa J Prosvirin AV Bera JK Tichy SE Schelter EJ Dunbar KR 《Inorganic chemistry》2004,43(4):1359-1369
The syntheses and characterization of two new, highly soluble, single-molecule magnets [Mn12O12(CF3COO16(H2O)4].2CF3COOH.4H2O (1) and Mn12O12(CF3COO16(H2O)4].CF3COOH.7H2O (2) are reported. Compound 1 was isolated from the reaction of Mn12O12(CF3COO16(H2O)4] with trifluoroacetic acid in CH2Cl2. Compound 1 crystallizes in the tetragonal space group Ifourmacr; (No. 82) with unit cell parameters a = b = 18.128(3) A, c = 13.048(3) A, V = 4287.9(19) A3, Z = 2 and is isostructural to [Mn12O12(CH3COO)16(H2O)4]. Compound 2 was prepared from the reaction of Mn12O12(CF3COO16(H2O)4] with neat trifluoroacetic acid, and crystallizes in the monoclinic space group P2(1)/n (No. 14) with unit cell parameters a = 15.221(8) A, b = 21.870(12) A, c = 27.217(15) A, beta = 90.53(1) degrees, V = 9060(9) A3, and Z = 4. The dc magnetic susceptibility measurements in the 2-300 K temperature range support a high-spin ground state. The magnetization data collected in the 1-7 T field range from 1.8 to 4.0 K were best fit to the parameters S = 10, g = 2.15, D = -0.65 cm(-1), and E = 0 cm(-1) for 1 and S = 10, g = 1.87, D = -0.34 cm(-1), and E = -0.10 cm(-1) for 2. The ac susceptibility data for compound 1 reveal out-of-phase (chi(m)") signals in the 4-7 K temperature range, whereas the chi(m)" signals for compound 2 appear below temperatures of 4 K. This variation in blocking temperatures is a consequence of the two different crystallographic forms of compounds 1 and 2. Compound 1 exhibits the same structural geometry and distortions found in [Mn12O12(CH3COO)16(H2O)4], while compound 2 is of lower molecular symmetry with two Jahn-Teller axes of distortion being oriented along oxide ligands. This different structural arrangement facilitates a different tunneling pathway that leads to a lower effective barrier for magnetization reorientation for compound 2. The substitution of the acetate ligands by trifluoroacetic acid was monitored by mass spectrometry, which is a convenient tool for judging completion of the substitution process. 相似文献
107.
N.A. Valisheva O.E. Tereshchenko I.P. Prosvirin E.E. Rodjakina 《Applied Surface Science》2010,256(19):5722-5726
The composition and morphology of fluorinated anodic oxide (FAO) films grown on InAs (1 1 1)A in alkaline aqueous (pH 11.5) and acid waterless (pH 1.5) electrolytes are studied by means of X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and high resolution transmission electron microscopy (HRTEM) in order to reveal the passivation mechanism of fluorine on the FAO/InAs(1 1 1)A interface. The formation of the highest oxidation form of As+5 and passivation of defects in the FAO layers during the fluorination process explain the reduction of the density of surface states and unpinning of the Fermi level on the fluorinated AO/InAs(1 1 1)A interface. 相似文献
108.
Gritsenko V. A. Kruchinin V. N. Prosvirin I. P. Novikov Yu. N. Chin A. Volodin V. A. 《Journal of Experimental and Theoretical Physics》2019,129(5):924-934
Journal of Experimental and Theoretical Physics - The atomic structure and the electronic spectrum of a-SiNx:H films, which are grown by plasmachemical deposition with varied ammonia and monosilane... 相似文献
109.
Borchert H Borchert Y Kaichev VV Prosvirin IP Alikina GM Lukashevich AI Zaikovskii VI Moroz EM Paukshtis EA Bukhtiyarov VI Sadykov VA 《The journal of physical chemistry. B》2005,109(43):20077-20086
Nanostructured ceria doped with other rare earth elements is a good oxygen ion conductor, which gives rise to various catalytic applications such as the construction of membranes for syngas production by partial oxidation of methane. This article focuses on the Gd-doped cerium dioxides, which can be modified with Pt or Pd to enhance the reactivity of the lattice oxygen in interaction with methane. The aim of the work is the elucidation of correlations between the structural, electronic, and chemical properties of these nanomaterials. Detailed studies were performed for a series of samples with and without surface modification by noble metals using a complex combination of physicochemical methods: XRD, TEM, CH(4) TPR, XPS, SIMS, and FTIR spectroscopy of adsorbed CO. XPS and TPR data revealed that surface modification with noble metals enhances the reducibility of the doped ceria support, where the effect is more pronounced for Pd than for Pt. The formation of highly cationic Pd species due to strong metal support interactions provides a possible explanation for this behavior. Furthermore, the results obtained in the present work for the Gd-doped ceria system are compared to those obtained previously for the Pr-doped ceria system. 相似文献
110.
V. I. Prosvirin 《Mechanics of Composite Materials》1970,6(3):399-403
"Silver" type microcracks in polymethyl methacrylate are self-removed on aging. Dry friction can assist in their accelerated removal; by intensifying relaxation processes and causing flow in the surface layer of the polymer, it is able to restore both the polymer structure in the zones of "silver" type microcracks and also to age obvious microcracks. The restored polymer quality is stable. Dry friction raises the resistance of polymethyl methacrylate to splitting in failure.Lenin Civil Aviation Engineering Institute. Translated from Mekhanika Polimerov, No. 3, pp. 465–470, May–June, 1970. 相似文献