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681.
682.
Yuto Nagura Jiro Kasahara Yuta Sugiyama Akiko Matsuo 《Proceedings of the Combustion Institute》2013,34(2):1949-1956
The geometry and characteristic length of diffraction and re-initiation during a two-dimensional detonation propagation were revealed by visualization. C2H4 + 3O2 (unstable), 2C2H2 + 5O2 + 7Ar (stable) and 2C2H2 + 5O2 + 21Ar (stable) were used as the test mixtures. Experiments were performed over the deviation angle range from 30° to 150° and the initial pressure range from 15.8 to 102.3 kPa. By self-emitting photography, we confirmed that the geometry and the characteristic length of diffraction are not different among test gases, with the exception of the fan-like structure of re-initiation that occurred regardless of whether the mixture was unstable or stable. We conducted a compensative experiment by changing the deviation angle and initial pressure, and summarized the detonation diffraction by shadowgraph. At deviation angles larger than 60°, we measured the distances from the vertex of the channel corner to the point where the transverse detonation wave reflected on the under wall (= wall reflection distance) and confirmed that wall reflection distances are approximately in the range of 10–15 times the cell width, whether the mixture is unstable or stable. 相似文献
683.
For capillary zone electrophoresis, a new method of transformation from migration time to effective mobility was proposed, in which the mobility increase due to Joule heating and the relaxation effect of the potential gradient were eliminated successfully. The precision of the mobility evaluated by the proposed transformation was discussed in relation to the analysis of rare earth ions. By using the transformation, almost the same pherograms could be obtained even from the pherograms obtained originally at different applied voltages. 相似文献
684.
The chromatographic behavior of manno-oligosaccharides derived from Saccharomyces cerevisiae mannan on two kinds of HPLC columns, an aminopropyl-silica column or a graphitized carbon column (GCC), was investigated. The order of elution of manno-oligosaccharides on both columns with acetonitrile-water was almost the same, that is, the retention increased with increasing molecular size. However, the GCC made it possible to isolate completely two isomers of mannotrioses (M(3)-1 and M(3)-2) with different linkage positions. We reinvestigated the structures of mannobiose (M(2)), M(3)s, and mannotetraose (M(4)) that were completely isolated by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and NMR spectroscopy. 相似文献
685.
A kinetic-spectrophotometric method for the determination of bromide (0.004–0.3 mg l?1) based on its catalysis of the oxidation of pyrocatechol violet by hydrogen peroxide in HCl/H2SO4 is described. The effect of bromide is greatly increased in the presence of large amounts of chloride. The relative standard deviations are 6.4 and 13% for 0.034 and 0.010 mg l?1 bromide, respectively (n = 10). Most ions commonly occurring in natural waters do not interfere except for iodide. 相似文献
686.
Shigeru Ikuta 《Journal of computational chemistry》1985,6(2):116-121
Third-order Møller–Plesset perturbation theory (MP 3) with a 6-31G** basis set was applied to study the relative stabilities of H+(X)2 conformations (X ? CO and N2) and their clustering energies. The effect of both basis set extensions and electron correlation is not negligible on the relative stabilities of the H+(CO)2 clusters. The most stable conformation of H+(CO)2 is found to be a C∞v structure in which a carbon atom of CO bonds to the proton of H+(CO), whereas that of H+(N2)2 is a symmetry D∞h structure. The second lowest energy conformations of H+(CO)2 and H+(N2)2 lie within 2 kcal/mol above the energies of the most stable structures. Clustering energies computed using MP 3 method with the 6-31G** basis set are in good agreement with the experimental findings of Hiraoka, Saluja, and Kebarle. The low-lying singlet conformations of H+(X)3 (X ? CO and N2) have been studied by the use of the Hartree–Fock MO method with the 6-31G** basis set and second-order Møller–Plesset perturbation theory with a 4-31G basis set. The most stable structure is a T-shaped structure in which a carbon atom of CO (or a nitrogen atom of N2) attacks the proton of the most stable conformation of H+(X)2 clusters. 相似文献
687.
Makoto Yanaga Kazutoyo Endo Hiromichi Nakahara Shigeru Ikuta Taichi Miura Masashi Takahashi Masuo Takeda 《Hyperfine Interactions》1991,62(4):359-372
The relationship between the isomer shifts in Mössbauer spectroscopy and the electron contact densities has been investigated for several antimony and tin compounds. Mössbauer spectra for121Sb in rapidly frozen solutions of antimony compounds were measured. The isomer shifts are compared with the valence electron densities at the antimony nucleus calculated with theab initio molecular orbital method. The relative difference of the nuclear charge radius ΔR/R could be obtained as ΔR/R =?(10.2±1.0)×10?4 for the 37.15 keV M1 transition of121Sb. Further, some computations of the electron density at the tin nucleus for several tin compounds were performed. By comparing the valence electron contact densities with isomer shifts, which had been reported for several tin compounds in rare-gas matrix states, the value of ΔR/R for 23.87 keV M1 transition in119Sn was estimated to be (1.57±0.03)×10?4. 相似文献