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21.
A. Kh. Mamleev R. V. Galeev L. N. Gunderova M. G. Faizullin A. A. Shapkin 《Journal of Structural Chemistry》2008,49(4):639-643
The microwave spectrum of 5-methyl-1,3-dioxane was studied in the frequency range 12–35 GHz. The a and c type rotation transitions with J≤30 were identified. The rotational constants A = 4658.5244(33) MHz, B = 2383.3930(12) MHz, and C = 1724.28907(88) MHz and the quartic constants of the centrifugal distortion of the molecule in the ground vibrational state were determined. The components of the dipole moment were found, μ a = 1.76 ± 0.01 D and μ c = 1.10 ± 0.01 D; the net dipole moment of the molecule is μ = 2.08 ± 0.01 D. 5-Methyl-1,3-dioxane was calculated by the B3PW91/aug-cc-pVDZ density functional theory method. The calculated data are compared with the experimental data. The most stable conformation is the chair conformation with an equatorial orientation of the methyl group. 相似文献
22.
Barney?L.?BalesEmail author M.?M.?Bakirov R.?T.?Galeev I.?A.?Kirilyuk A.?I.?Kokorin K.?M.?Salikhov 《Applied magnetic resonance》2017,48(11-12):1399-1445
Experimental studies of 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (Tempol) in 60 wt% aqueous glycerol were carried out for temperatures from 273 to 340 K. Selective isotope substitution allowed comparisons between the experimental spectral manifestations of spin exchange and dipole–dipole interactions for protonated, deuterated, 15N, and 14N Tempol. Theoretical spectra were computed from a rigorous theory specifically formulated to include proton hyperfine interactions over a wide range of spin exchange and dipole–dipole interactions to compare with the experimental data. For spin exchange and dipole–dipole interactions small compared with the proton hyperfine coupling constant, spectra were calculated with perturbation theory to gain insight into the behavior of individual proton lines. The theoretical and experimental spectra were analyzed by least-squares fitting to Voigt shapes or by a new two-point method. For most accessible experimental designs, the comparisons are rather good; however, for an experiment constrained to low concentrations and high viscosities, the methods are less accurate. 相似文献
23.
Constantin Romanescu Timur R. Galeev Wei‐Li Li Alexander I. Boldyrev Lai‐Sheng Wang 《ChemInform》2012,43(2):no-no
Co@B‐8, Ru@B‐9, Co@B8, and Ru@B9 clusters are characterized by photoelectron spectroscopy and DFT calculations. 相似文献
24.
S. P. Savin L. M. Zelenyi S. A. Romanov S. I. Klimov A. A. Skalsky A. A. Galeev V. N. Smirnov M. N. Nozdrachev Yu. I. Yermolaev L. A. Avanov E. Amata J. Blecki J. Buechner B. Nikutowski É. M. Dubinin Z. Nemecek J. Safrankova A. Pedersen J. L. Rauch J. Rustenbach J. A. Sauvaud P. Song K. Stasiewicz 《JETP Letters》2001,74(11):547-551
A new phenomenon was discovered on the basis of analysis of the Interball project data. A hot plasma flow is thermalized through the formation of “long-operating” vortex streets and local discontinuities and solitons in a distributed region over polar cusps. Plasma percolation through the structured boundary and secondary reconnection of fluctuating magnetic fields in a high-latitude turbulent boundary layer account for the main part of solar wind plasma inflow into the magnetospheric trap. Unlike local shocks, the ion thermalization is accompanied by the generation of coherent Alfvén waves on the scales ranging from ion gyroradius to the radius of curvature of the averaged magnetic field, as well as by the generation of diamagnetic bubbles with a demagnetized heated plasma inside. This “boiling” plasma has a frequency region where the spectrum is different from the Kolmogorov law (with slopes 1.2 and 2.4 instead of 5/3 or 3/2). The fluctuation self-organization in the boundary layer (synchronization of three-wave decays) was observed on certain frequency scales. 相似文献
25.
Yatsishina E. B. Vasilyev S. V. Vasilieva O. A. Galeev R. M. Dyuzheva O. P. Kovalchuk M. V. 《Crystallography Reports》2020,65(6):1064-1072
Crystallography Reports - A detailed analysis of the inner structure and specific features of mummification and decoration of ancient Egyptian mummy from the Pushkin State Museum of Fine Arts,... 相似文献
26.
27.
A. D. Antuf’eva M. V. Dmitriev O. A. Maiorova I. G. Mokrushin A. R. Galeev E. V. Shklyaeva G. G. Abashev 《Russian Journal of Organic Chemistry》2018,54(9):1350-1357
A series of ferrocenyl-substituted methyl ketones and chalcones were synthesized and converted to unsymmetrical 4,6-disubstituted pyrimidin-2-amines and 2-(1H-pyrrol-1-yl)pyrimidines in which the ferrocene fragment is separated from the pyrimidine ring by π-deficient (pyridine) or π-excessive (thiophene) heterocycle. The forbidden band gap of the obtained compounds was determined on the basis of their UV spectra (\(E_{\text{g}}^{\text{opt}}\) = 1.75?2.36 eV), and their electrochemical properties were studied. The presence of a thiophene ring between the ferrocene and pyrimidine fragments reduces the redox potential of the ferrocene fragment (20?30 mV), whereas pyridine spacer between the ferrocene and pyrimidine fragment increases the redox potential of the ferrocene fragment by more than 100 mV. 相似文献
28.
A. Kh. Mamleev L. N. Gunderova R. V. Galeev A. A. Shapkin M. G. Faizullin A. P. Nikitina D. V. Shornikov E. A. Kantor 《Journal of Structural Chemistry》2007,48(6):1030-1035
The microwave spectra of five isotopomers with the 13C and 18O natural abundance isotopes of the 2-methyl-1,3-dioxane molecule (22–50 GHz) were studied. Rotational transitions of a and c types with 4 ≤ J ≤ 12 were identified. The rotational constants and the substitution r s and effective r o structural parameters of the molecule were determined. Ab initio calculations on 2-methyl-1,3-dioxane were performed with molecular structure optimization. The results of quantum-chemical calculations at different levels are compared with experimental data. 相似文献
29.
R. I. Khusnutdinov D. K. Galeev A. I. Malikov U. M. Dzhemilev O. M. Nefedov 《Russian Chemical Bulletin》1994,43(11):1871-1872
endo,exo-Hexacyclo[9.2.02,10.03,8.04,6.05,9]tetradec-12-ene (1) undergoes cyclocodimerization with quadricyclane (Q) in the presence of the Pd(PPh3)4 complex to giveexo,exo,endo,exo-decacyclo[9.9.1.02,10.03,8.04,6.05,9.012,20.013,18.014,16.015,19]heneicosane (2) andendo,exo,endo,exo-decacyclo[9.9.1.02,10.03,8.04,6.05,9.012,20.013,18.014,16.015,19]heneicosane (3) in a ratio of 10 7 (yield up to 26 %). Simultaneously, homocyclotrimerization of Q occurs to give three known C21 hydrocarbons (4–6). The yields of compounds2 and3 and the selectivity of the process depend considerably on the reaction conditions and the molar ratio of1 and Q. Compounds2 and3 that were obtained were characterized by13C NMR spectra.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1983–1985, November, 1994. 相似文献
30.
Galeev R. V. Gunderova L. N. Mamleev A. H. Shapkin A. A. Pozdeev N. M. Grikina O. E. Proskurnina M. V. Khaikin L. S. 《Russian Chemical Bulletin》2001,50(9):1605-1611
The microwave spectrum of 2-chloro-4,5-dimethyl-1,3,2-dioxaphospholene (1) was studied in the frequency range from 7 to 53 GHz. Rotational transitions of the parent molecule in the ground and eleven excited vibrational states and those of its mono-substituted 37Cl, 13CMe, and 13CCycle isotopomers in the ground vibrational state were identified. Rotational constants and partial r
s-structure were obtained. The quartic centrifugal distortion constants, dipole moment components a = 3.8D and c = 0.24D (the total dipole moment is 3.81D), and the 35Cl quadrupole coupling constants were determined for the parent molecule. The fine structure of the microwave transitions in the parent molecule was analyzed under the assumption of noninteracting methyl groups. The height of the barrier to internal rotation (V
30 = V
03 = 665 cm–1) and the frequency of torsional vibrations ( = 167 cm–1) were found. The frequencies of two lowest vibrational modes corresponding to deformation vibrations of the five-membered ring were estimated (100 cm–1) from the relative intensities of rotational transitions for different vibrational states. 相似文献