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471.
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474.
Natalia A. Romanova Nadezhda B. Tamm Vitaliy Yu. Markov Alexey A. Goryunkov Lev N. Sidorov Sergey I. Troyanov 《Mendeleev Communications》2012,22(6):297-298
Cs-C60(CF3)6 was synthesized by the reaction of S6-C60(CF3)12 with C60 at 530 °C. Its molecular structure with skew-pentagonal- pyramidal addition pattern was elucidated by single crystal X-ray diffraction. Theoretical DFT calculations were performed to account for a high degree of fragmentation in negative-ion mass spectra. 相似文献
475.
The effect of morpholine and piperidine on the kinetics of complex formation between zinc acetate and octa(m-trifluoromethylphenyl)porphyrazine in benzene has been studied. Possible scheme of the complex formation has been suggested. The effect of proton-accepting properties of the additive on the rate constants has been demonstrated. 相似文献
476.
Anatoliy I. Polyakov Vera A. Eryomina Lidiya A. Medvedeva Nadezhda I. Tihonova LeoniD. G. Voskressensky 《Journal of heterocyclic chemistry》2008,45(6):1589-1596
477.
Gushchin PV Tyan MR Bokach NA Revenco MD Haukka M Wang MJ Lai CH Chou PT Kukushkin VY 《Inorganic chemistry》2008,47(24):11487-11500
The tailoring reaction of the two adjacent nitrile ligands in cis-[PtCl(2)(RCN)(2)] (R = Me, Et, CH(2)Ph, Ph) and [Pt(tmeda)(EtCN)(2)][SO(3)CF(3)](2) (8.(OTf)(2); tmeda = N,N,N',N'-tetramethylethylenediamine) upon their interplay with N,N'-diphenylguanidine (DPG; NH=C(NHPh)(2)), in a 1:2 molar ratio gives the 1,3,5-triazapentadiene complexes [PtCl(2){NHC(R)NHC(R)=NH}] (1-4) and [Pt(tmeda){NHC(Et)NHC(Et)NH}][SO(3)CF(3)](2) (10.(OTf)(2)), respectively. In contrast to the reaction of 8.(OTf)(2) with NH=C(NHPh)(2), interaction of 8.(OTf)(2) with excess gaseous NH(3) leads to formation of the platinum(II) bis(amidine) complex cis-[Pt(tmeda){NH=C(NH(2))Et}(2)][SO(3)CF(3)](2) (9.(OTf)(2)). Treatment of trans-[PtCl(2)(RCN)(2)] (R = Et, CH(2)Ph, Ph) with 2 equiv of NH=C(NHPh)(2) in EtCN (R = Et) and CH(2)Cl(2) (R = CH(2)Ph, Ph) solutions at 20-25 degrees C leads to [PtCl{NH=C(R)NC(NHPh)=NPh}(RCN)] (11-13). When any of the trans-[PtCl(2)(RCN)(2)] (R = Et, CH(2)Ph, Ph) complexes reacts in the corresponding nitrile RCN with 4 equiv of DPG at prolonged reaction time (75 degrees C, 1-2 days), complexes containing two bidentate 1,3,5-triazapentadiene ligands, i.e. [Pt{NH=C(R)NC(NHPh)=NPh}(2)] (14-16), are formed. Complexes 14-16 exhibit strong phosphorescence in the solid state, with quantum yields (peak wavelengths) of 0.39 (530 nm), 0.61 (460 nm), and 0.74 (530 nm), respectively. The formulation of the obtained complexes was supported by satisfactory C, H, and N elemental analyses, in agreement with FAB-MS, ESI-MS, IR, and (1)H and (13)C{(1)H} NMR spectra. The structures of 1, 2, 4, 11, 13, 14, 9.(picrate)(2), and 10.(picrate)(2) were determined by single-crystal X-ray diffraction. 相似文献
478.
Belogurova NV Kudryasheva NS Alieva RR Sizykh AG 《Journal of photochemistry and photobiology. B, Biology》2008,92(2):117-122
Complex bioluminescence spectra of photoproteins from marine coelenterates - jellyfish Aequorea victoria and hydroid Obelia longissima, and photoluminescence spectra of the bioluminescent reaction products (Ca(2+)-discharged photoproteins) were deconvolved into components. The bioluminescence spectra of aequorin were found to include three, the bioluminescence spectra of obelin - four, and the photoluminescence spectra of the Ca(2+)-discharged photoproteins - only two components. The spectral components were assigned to one unionized and three ionized forms of coelenteramide. The changes in acidity of the excited coelenteramide molecule are discussed. The differences in bioluminescence and photoluminescence spectra are considered, with protonic environment of coelenteramide taken into account. 相似文献
479.
Andrii V. Kulinich Nadezhda A. Derevyanko Alexander A. Ishchenko Stanislav L. Bondarev Valeri N. Knyukshto 《Journal of photochemistry and photobiology. A, Chemistry》2008,200(2-3):106-113
The fluorescent properties of a series of symmetric cationic cyanine dyes and merocyanines with trimethylene bridge connecting N-atom of the indole residue with α-position of the polymethine chain have been explored in detail. It is shown that the constraining group influences their fluorescent properties both by steric and electronic effects. It revealed an essential decrease of the fluorescence quantum yields of the constrained symmetric cyanine dyes in comparison with those of their analogues without bridge group in their chromophore. This effect diminishes essentially at polymethine chain lengthening. In the case of merocyanines the bridge group can cause a decrease as well a substantial increase of their fluorescence quantum yields depending on their type of solvatochromism and solvent polarity. The conclusions made on the basis of the experimental data are in good agreement with the results of semiempirical quantum-chemical calculations. 相似文献
480.
Guillaume M Champagne B Markova N Enchev V Castet F 《The journal of physical chemistry. A》2007,111(39):9914-9923
The keto-enol (K-E) tautomerization equilibrium, more precisely, the keto-amine/enol-imine equilibrium, has been investigated for a series of substituted salicylideneanilines in view of designing compounds with a contrast of second-order nonlinear optical properties. Substituting the salicylidene ring by an acceptor group or the other ring by a donor prevents the K form from being stable, whereas in the other cases, the K form can easily be converted to the E form due to the small activation barrier, figuring out in most cases that the K form is metastable. For a representative set of donor/acceptor substituents, the E and K forms present a sufficiently large contrast of beta to allow its detection by using electric-field-induced second harmonic generation or hyper-Rayleigh scattering. The largest beta values are mainly associated with species bearing a donor in the para position of the salicylidene ring and an acceptor on the other ring whereas the largest beta values are generally found for the E form. 相似文献