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341.
G. N. Kuzmin M. V. Knatko S. V. Kurganov 《Reaction Kinetics and Catalysis Letters》1983,23(3-4):313-317
TPD studies of the established formation of ethane, ethylene and propylene in the irradiated CH4/TiO2 system indicate that the process is most effective under X-ray or long-wavelength light irradiation behind the edge of the fundamental absorption band of the oxide.
, CH4/TiO2, .相似文献
342.
Quenching of triplet states of carbocyanine dyes by nitroxyl radical has been investigated by the flash photolysis method. Quenching of triplet state carbocyanine dyes with one polymethyne chain occurs via enhanced intersystem crossing on exchange interaction with the radical. Quenching of triplet state carbocyanine dyes with two polymethyne chains occurs via partial charge transfer in the collision complex with the radical. In the second case, an increase in the dielectric constant of the solvent leads to an increase of the rate of quenching. In high polarity solvents (propanol, methanol) complete electron transfer from dye triplet state to radical occurs. Kinetic and spectral characteristics of a new dye radical (Dye.+) are reported. 相似文献
343.
Experimental data obtained by the authors themselves and other published data on the dependence of the rate constants of internal conversion and intersystem crossing in exciplexes (back electron transfer) on the value of energy gap were critically revisited. The conclusion that these processes occur according to the mechanism of radiationless diabatic quantum transitions, rather than the preceding thermally activated solvent and reactant reorganizations was substantiated.Translated from Khimiya Vysokikh Energii, Vol. 39, No. 2, 2005, pp. 114–125.Original Russian Text Copyright © 2005 by Kuzmin, Soboleva, Dolotova, Dogadkin.This revised version was published online in April 2005 with a corrected cover date. 相似文献
344.
The fluorescence lifetimes (τfl) of alkyl and alkoxy substituted dihydroquinolines (DHQ) were measured in hexane, isopropanol, methanol, and water. It was shown that τfl was determined by the solvent nature and weakly depended on substituents on the DHQ aromatic ring and heterocycle, with τfl being substantially lower in methanol than in the other solvents. The decrease in τfl in MeOH is caused by an increase in the rate constants of the photochemical reaction and nonradiative transitions in this solvent. The quantum yield of fluorescence in H2O and MeOH, in which the photoinduced addition of the solvent molecules occurs, decreases with a decrease in the excitation wavelength within the limits of long-wavelength absorption band, thus providing strong evidence that the photochemical reaction proceeds from the unrelaxed excited state. 相似文献
345.
V. E. Kuzmin I. S. Rublev D. V. Naroditskii E. V. Gapon 《Journal of Structural Chemistry》1995,36(5):798-802
New types of ligands for spherical ions have been designed as part of the molecular design strategy for supramolecular compounds.
In particular, symmetric conformers of macrocycles, built of −(CH2)n−O−(n=3,4,5) fragments, which envelope the spherical ion in a complementary way, have been constructed. Alos, new types of
“bracelentands” with different, “hardening” fragments are suggested. Using the molecular mechanics methods, the selectivity
of complex formation of the ligands with respect to alkaline metal ions has been investigated.
A. V. Bogatskii Physicochemical Institute, Ukrainian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 5, pp. 879–883, September–October, 1995.
Translated by L. Smolina 相似文献
346.
D. N. Dogadkin E. V. Dolotova I. V. Soboleva M. G. Kuzmin B. F. Plyusnin I. P. Pozdnyakov V. P. Grivin D. Phillips K. Murphy 《High Energy Chemistry》2004,38(6):386-391
The quantum yields of the formation of triplet states from the exciplexes of 9-cyanophenanthrene with 1,2,3- and 1,3,5-trimethoxybenzenes in solvents of different polarity and the rate constants of intersystem crossing in these exciplexes were measured. In the solvents of weak and intermediate polarity, the exciplexes decay predominantly via internal conversion and intersystem crossing, whereas the decay in polar solvents occurs additionally via dissociation into radical ions. 相似文献
347.
F. Rocca C. Armellini M. Ferrari G. Dalba N. Diab A. Kuzmin F. Monti 《Journal of Sol-Gel Science and Technology》2003,26(1-3):267-271
Rare-earth (Pr3+, Tb3+, Er3+) doped silica xerogels were studied by x-ray absorption spectroscopy and x-ray diffraction. A change of the local environment around rare-earth ions upon xerogel densification at 900–950°C and co-doping with aluminum ions was determined from the rare-earths L3-edge EXAFS signals. The densification process induces a decrease of the coordination number and a compression and deformation of the first coordination shell, composed of oxygen atoms. The second coordination shell, composed of silicon and/or aluminum ions, also experiences some modification, which is attributed mainly to a shortening of the shell radius. No evidence of clustering of rare-earth ions upon densification was observed. X-ray diffraction data on Tb-doped gels confirm the EXAFS results. 相似文献
348.
V. A. Kuzmin T. A. Podrugina T. D. Nekipelova I. A. Doroshenko M. V. Proskurnina G. V. Golovina E. V. Radchenko A. A. Kostyukov V. V. Temnov E. D. Matveeva V. A. Palyulin N. S. Zefirov 《Doklady Chemistry》2016,470(1):264-267
New tricarbocyanine dyes with phosphonate groups (2, 3) were synthesized and their binding constants to bovine serum albumin (BSA) were determined. The binding constants of the synthesized tricarbocyanines and cardiogreen (1) (Kb ~ 105 M–1) are similar, indicating an insignificant contribution of the Coulomb interaction to the complex formation, which is determined by the polymethine chain interaction with BSA. The fluorescence lifetimes attest to the formation of two types of complexes: the lifetime of the dye complex with BSA with a major contribution (~80%) is 740–800 ps, and a lifetime of ~210 ps corresponds to the complex of dye aggregates with BSA. 相似文献
349.
Temperature‐dependent EXAFS study of the local structure and lattice dynamics in cubic Y2O3 下载免费PDF全文
Inga Jonane Karlis Lazdins Janis Timoshenko Alexei Kuzmin Juris Purans Pavel Vladimirov Tim Gräning Jan Hoffmann 《Journal of synchrotron radiation》2016,23(2):510-518
The local structure and lattice dynamics in cubic Y2O3 were studied at the Y K‐edge by X‐ray absorption spectroscopy in the temperature range from 300 to 1273 K. The temperature dependence of the extended X‐ray absorption fine structure was successfully interpreted using classical molecular dynamics and a novel reverse Monte Carlo method, coupled with the evolutionary algorithm. The obtained results allowed the temperature dependence of the yttria atomic structure to be followed up to ~6 Å and to validate two force‐field models. 相似文献
350.
Synthesis,Structure, and Properties of the Fullerene C60 Salt of Crystal Violet, (CV+)(C60.−)⋅0.5 C6H4Cl2, which Contained Closely Packed Zigzagged C60.− Chains 下载免费PDF全文
Dr. Dmitri V. Konarev Dr. Alexey V. Kuzmin Dr. Salavat S. Khasanov Dr. Manabu Ishikawa Dr. Akihiro Otsuka Prof. Hideki Yamochi Prof. Dr. Gunzi Saito Prof. Rimma N. Lyubovskaya 《化学:亚洲杂志》2016,11(11):1705-1710
The reduction of fullerene C60 by zinc dust in the presence of crystal violet cations (CV+) yielded a deep‐blue solution, from which crystals of (CV+)(C60.?) ? 0.5 C6H4Cl2 ( 1 ) were obtained by slow mixing with n‐hexane. The salt contained isolated, closely packed zigzagged chains that were composed of C60.? radical anions with a uniform interfullerene center‐to‐center distance of 9.98 Å. In spite of the close proximity of the fullerenes, they did not dimerize, owing to spatial separation by the phenyl substituents of CV+. The room‐temperature conductivity of compound 1 was 3×10?2 S cm?1 along the fullerene chains. The salt exhibited semiconducting behavior, with an activation energy of Ea=167 meV. Spins localized on C60.? were antiferromagnetically coupled within the fullerene chains, with a Weiss temperature of ?19 K without long‐range magnetic ordering down to 1.9 K. 相似文献