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Won Young Jung Seung Hee Baek Seong Soo Park Gun-Dae Lee Euh Duck Jeong Hyun Gyu Kim Seong-Soo Hong 《Reaction Kinetics and Catalysis Letters》2007,91(2):233-240
The nanosized titania and TiO2/SiO2 particles were prepared by the microwave-hydrothermal method. The effect of physical properties TTIP/TEOS ratio and calcination
temperature has been investigated. The major phase of the pure TiO2 particle is of the anatase structure, and a rutile peak was observed above 800°C. In TiO2/SiO2 particles, however, no significant rutile phase was observed, although the calcination temperature was 900°C. No peaks for
the silica crystal phase were observed at either silica/titania ratio. The crystallite size of TiO2/SiO2 particles decreases as compared to pure TiO2 at high calcination temperatures. The TiO2/SiO2 particles show higher activity on the photocatalytic decomposition of orange II as compared to pure TiO2 particles. 相似文献
3.
Ji Duck Kim 《Tetrahedron letters》2005,46(7):1079-1082
Diastereoselective synthesis of 1,2-amino alcohols was achieved from a highly diastereoselective allylic amination reaction of α-hydroxy allyl ethers using chlorosulfonyl isocyanate. Diastereoselectivities varied depending on the stereochemistry of the ethers used and the stability of the carbocation intermediate obtained during the reaction. We propose that this CSI reaction is the results of either a SNi or SN1 mechanism, according to the stability of the carbocation intermediate. 相似文献
4.
Hydrolyses of phosphorus halides, (RO)(2)POX where R = H or Me and X = F or Cl, in the gas phase and in the reaction field have been investigated theoretically with ab initio and the density functional theory (DFT). The free energy of activation in the reaction field was also estimated using the Onsager method with a correction of entropy change and basis set superposition error (BSSE). The reaction of (MeO)(2)POF proceeds through a path with bifunctional catalysis regardless of the medium, but the reaction of (MeO)(2)POCl proceeds through bifunctional and general base catalysis in the gas phase and in water, respectively. The estimated free energy barrier of 23 kcal/mol for the hydrolysis of (MeO)(2)POF is in good agreement with the experimental values of 24 kcal/mol, and relative barrier of 3 kcal/mol to the (MeO)(2)POCl is also in good agreement with the experimental values of 5 kcal/mol of diisopropyl phosphorus halides ((Pr(i)O)(2)POX, X = F and Cl). 相似文献
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Isolated V? centres with g⊥ values of 2.0672 and 2.0667 are observed after proton irradiation of CaO and SrO. The behaviour of these centres after thermal and γ-irradiation treatment of the sample indicates that a vacancy aggregate or complex is proton irradiation. The VOH centre is formed at a higher temperature consistent with the hypothesis that the original proton reacts to form a hydroxyl group. 相似文献
10.
R.D. Felder T.M. Williams G.S. Mutchler I. Duck J. Hudomalj-Gabitzsch M. Furic D. Mann N.D. Gabitzsch J.M. Clement G.C. Phillips T.R. Witten E.V. Hungerford M. Warneke B.W. Mayes L.Y. Lee J.C. Allred 《Nuclear Physics A》1977,280(2):308-324
Neutron-proton final state interactions (FSI) were observed in the deuteron breakup reaction 2H(p, 2p)n-via a kinematically complete experiment at incident proton energies of 585 and 800 MeV. Kinematic conditions were chosen which allowed the final state proton and neutron to have small relative energies; data were taken at four proton c.m. scattering angles at 800 MeV, ranging from 71° to 119° and at 94° and 106° at 585 MeV. The data are analyzed in terms of the Goldberger-Watson formalism for final state interactions, and the individual contributions of the 1S0 and 3S1 np states are determined. The ratio is large, as expected from some reaction models. The ratio of 3S1 (almost elastic) to pd elastic cross sections is in good agreement with FSI analysis. 相似文献