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91.
T. I. Liskovskaya P. P. Semyannikov I. A. Baidina P. A. Stabnikov N. V. Pervukhina V. A. Logvinenko I. K. Igumenov I. E. Sokolov 《Journal of Structural Chemistry》2006,47(4):726-734
Seven copper(II) bis-chelates derived from novel sterically hindered ligands — methoxy-β-diketones 相似文献
92.
I. K. Igumenov A. E. Turgambaeva V. V. Krisyuk 《Russian Journal of Applied Chemistry》2016,89(12):1903-1931
Data on volatile zirconium(IV) complexes are considered from the viewpoint of search for compounds exhibiting the required thermal parameters for centrifugal separation of stable isotopes. The results of studies concerning thermodynamics of vaporization of volatile zirconium compounds with inorganic and organic ligands are summarized and analyzed. The influence of the electronic structure of the central atom and of the molecular and crystal structure on the volatility of zirconium compounds is discussed. Promising lines of searching for volatile zirconium compounds for the development of low-activation materials based on isotopically altered elements are outlined. 相似文献
93.
G. I. Zharkova I. A. Baidina P. A. Stabnikov I. K. Igumenov 《Journal of Structural Chemistry》2006,47(4):716-725
Trans-and cis-complexes of platinum(II) with trifluoroacetylacetone (Pt(tfa)2) have been prepared and studied. The synthesis and the separation technique for the isomers are described. Temperature dependencies of saturated vapor pressure measured with a spoon gauge are reported for the cis-Pt(tfa)2 and trans-Pt(tfa)2 complexes. The isomers show a significant difference in volatility. The structural study of Pt(tfa)2 isomers has been performed. Molecular packings in the crystal of each isomer are considered on the base of structural data. The calculation of van der Waals energy of the crystal lattice of cis-Pt(tfa)2 and trans-Pt(tfa)2 was made by the atom-atom potential technique, their values being compared with experimental ΔH T 0 values of sublimation for the complexes. 相似文献
94.
P. A. Stabnikov I. A. Baidina S. V. Sysoev N. S. Vanina N. B. Morozova I. K. Igumenov 《Journal of Structural Chemistry》2003,44(6):1054-1061
A comprehensive study of copper(II) bis-ketoiminate including tensimetric analysis of sublimation and structure solution has been carried out. The temperature dependence of saturated vapor pressure over Cu(ki)2 crystals derived by the flow method is expressed by the equation lnP(atm)} = 25.31-13750/T, H
subl = -114.2 ± 1.3 kJ· mole-1, Ssubl =210.2 ± 3.0> J· mole-1 · K-1. Crystal data for CuO2N2C10H16: a=15.143(3), b=16.681(8), c=13.795(32) , space group Ccca, Z=12, d
calc = 1.47 g/cm3, R=0.029. The structure is molecular and consists of crystallographically independent Cu(ki)2 complexes of two types, one with a cis structure and the other with a cis–trans disordering. The copper atom has a plane square environment of two oxygen and two nitrogen atoms. In the cis isomer, Cu–O 1.938 and Cu–N 1.895 ; in the disordered complex, all four Cu–O(N) distances are 1.901 . 相似文献
95.
O. A. Mironov M. Myronov S. Durov V. T. Igumenov V. M. Konstantinov V. V. Paramonov T. Zhang L. F. Cohen 《Physica E: Low-dimensional Systems and Nanostructures》2004,20(3-4):523
Magnetotransport at fields up to 500 mT and LF-noise characteristics are reported for miniature magnetoresistors with ferrite concentrators based on Sn-doped n-InSb/i-GaAs heterostructures grown by MBE. The thickness of the InSb epilayers lie in the range 0.55–1.5 μm giving room temperature mobilities of 2.5–5.5 m2 V−1 s−1 with carrier densities of (0.5–1.5)×1017 cm−3. The room temperature magnetoresistance (MR) for our two terminal devices could be as high as 115% at 50 mT which is comparable to the extraordinary MR (ExMR) recently reported in microscopic composite van der Pauw disks four terminal devices [Science 289 (2000) 1530]. In addition, a high signal-to-noise ratio and a good temperature stability of R(B)/R0=0.5–0.83% K−1 was observed for B<60 mT (below the saturation field Bsat for ferrite). Device resistance stability R0(T) was equal to 0.27–0.66% K−1 in zero field with a nominal device resistance R0=197–224 Ω for DC currents in the range I=0.01–1.0 mA. The minimum detectable magnetic field is estimated from the reduced differential MR (∂R/∂B)/R=2000% T−1 at B=31 mT and normalised 1/f current noise power spectral density measured at the same field. The resolution limit Bmin=2.6 nT at 102 Hz and Bmin=0.82 nT at 103 Hz. These resolution limits are seven times better than those recently reported for the same material n-InSb/i-GaAs and ferrite fabricated Hall sensors [Magnetotransport and Raman characterization of n-InSb/i-GaAs epilayers, for Hall sensors applications over extremely wide ranges of temperature and magnetic field, Proceedings NGS 10, IPAP Conference Series 2, IPAP, Tokyo, 2001, pp. 151–154]. 相似文献
96.
A. S. Parshin A. Yu. Igumenov Yu. L. Mikhlin O. P. Pchelyakov V. S. Zhigalov 《Physics of the Solid State》2016,58(5):908-914
The inelastic electron scattering cross section spectra of Fe have been calculated based on experimental spectra of characteristic reflection electron energy loss as dependences of the product of the inelastic mean free path by the differential inelastic electron scattering cross section on the electron energy loss. It has been shown that the inelastic electron scattering cross-section spectra have certain advantages over the electron energy loss spectra in the analysis of the interaction of electrons with substance. The peaks of energy loss in the spectra of characteristic electron energy loss and inelastic electron scattering cross sections have been determined from the integral and differential spectra. It has been shown that the energy of the bulk plasmon is practically independent of the energy of primary electrons in the characteristic electron energy loss spectra and monotonically increases with increasing energy of primary electrons in the inelastic electron scattering cross-section spectra. The variation in the maximum energy of the inelastic electron scattering cross-section spectra is caused by the redistribution of intensities over the peaks of losses due to various excitations. The inelastic electron scattering cross-section spectra have been analyzed using the decomposition of the spectra into peaks of the energy loss. This method has been used for the quantitative estimation of the contributions from different energy loss processes to the inelastic electron scattering cross-section spectra of Fe and for the determination of the nature of the energy loss peaks. 相似文献
97.
Tamara Basova Petr Semyannikov Vladimir Plyashkevich Aseel Hassan Igor Igumenov 《固体与材料科学评论》2009,34(3-4):180-189
The current review summarizes the data of saturated vapor pressure and thermodynamic parameters of the sublimation process of different phthalocyanines as reported in the literature as well as in our work. The volatility of phthalocyanines is analyzed from the standpoint of their molecular and crystal structure. The differences in the saturated vapor pressure value of the investigated phthalocyanines may reach some orders of magnitude and are determined by the Van der Waals and electrostatic interaction of the peripheral atoms of adjacent molecules, as well as to a specific interaction, the type and number of which depend on the type of molecules packing in the crystal. 相似文献
98.
Birol IIK Fatih AKAR Hüsnü CANKURTARAN
zlem CANKURTARAN 《Turkish Journal of Chemistry》2021,45(3):845
The selectivity of 4-(Decyloxy) benzoic acid (DBA) liquid crystal in surface adsorption region (303.2–328.2 K) and thermodynamic region (423.2 – 433.2 K) was investigated by inverse gas chromatography at infinite dilution (IGC-ID). The selectivity parameters of the structural isomer series named butyl acetate, butyl alcohol, and amyl alcohol series were calculated for the DBA using IGC-ID technique. Additionally, the surface properties including dispersive surface energy (gS D), free energy (DGA S), enthalpy (DHA S), and acidity-basicity constants were calculated with net retention volumes obtained from IGC-ID experiment results. When the DHA S and DGA S are constants, DBA surface was found to be an acidic character (KD/KA @ 0.89). 相似文献
99.
Ksenia V. Zherikova Natalia B. Morozova Ludmila N. Zelenina S. V. Sysoev Tamara P. Chusova I. K. Igumenov 《Journal of Thermal Analysis and Calorimetry》2008,92(3):729-734
Five volatile hafnium(IV) and zirconium(IV) β-diketonates: hafnium(IV) acetylacetonate, hafnium(IV) trifluoroacetylacetonate,
hafnium(IV) pivaloyltrifluoroacetonate, hafnium(IV) 2,2,6,6-tetramethylheptane-3,5-dionate and zirconium(IV) 2,2,6,6-tetramethylheptane-3,5-dionate
were obtained, purified and identified. Thermal behavior of solid compounds was investigated by thermogravimetry (TG) and
differential scanning calorimetry (DSC) in helium atmosphere and in vacuum. DSC method was also used for definition of thermodynamic
characteristics of melting processes. Using the static method with quartz membrane zero-manometer and the flow method the
temperature dependencies of saturated vapor pressure for hafnium(IV) complexes was obtained. The standard thermodynamic characteristics
ΔH
T0 and ΔS
T0 of sublimation and evaporation processes were calculated from the temperature dependences of saturated vapor pressure. 相似文献
100.
L. N. Mazalov S. V. Trubina E. S. Fomin I. M. Oglezneva G. K. Parygina N. V. Bausk I. K. Igumenov 《Journal of Structural Chemistry》2004,45(5):800-807
The Cu(acac)2 complex was investigated by X-ray emission and XANES spectroscopy using synchrotron radiation. Structural data for the complex were obtained in chloroform solution and C2F matrix. The experimental spectra and their fitting on a single scale of binding energies point to possible relaxation effects. As shown by model quantum-chemical calculations, the structure and energy position of the LUMOs constructed from the vacant metal 4p, 5p AOs strongly depends on the nature of the nearest environment.Original Russian Text Copyright © 2004 by L. N. Mazalov, S. V. Trubina, E. S. Fomin, I. M. Oglezneva, G. K. Parygina, N. V. Bausk, and I. K. Igumenov__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 5, pp. 844–851, September–October, 2004. 相似文献