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81.
Intelligibility ratings of continuous discourse: application to hearing aid selection 总被引:1,自引:0,他引:1
Twelve normal-hearing subjects rated the intelligibility of 35-s, hearing-aid-processed continuous discourse (CD) passages. Three talkers (two male, one female), four hearing aids, and two signal-to-babble (S/B) ratios were used in a completely crossed design. Research questions concerned: (1) ability of listeners to rate intelligibility, (2) sensitivity of hearing aid rankings were based on intelligibility ratings for three CD passages per instrument, and (3) dependence of hearing aid rankings on (a) S/B ratio, and (b) talker characteristics. Results were: (1) listeners were able to rate intelligibility, (2) rankings based on intelligibility ratings of three CD passages per hearing aid were capable of identifying two superior instruments within a group of four hearing aids that were similar in frequency/gain function, (3) listening in a more difficult S/B ratio substantially decreased the sensitivity of the hearing aid rankings for the female talker but had only minor effects on the rankings for the male talkers, and (4) hearing aid intelligibility rankings were found to be different for different talkers. Applications to hearing aid selection are discussed. 相似文献
82.
The 13C? 13C spin coupling constants have been determined in substituted [1-13C]tetrahydronaphthylenes, [5-13C]hexahydrobenzanthracenes and [5-13C]benzanthracene. In addition, the 13C? 13C spin coupling constants for 7-hydroxy[7-13C]benzopyrene, trans-7,8-dihydro[7-13C]benzopyrene-7,8-diol and trans-7,8-dihydro[10-13C]benzopyrene-7,8-diol are reported, together with the one-bond carbon-carbon coupling constants between C-4 and C-5 in selected 4,5-disubstituted benzopyrenes. Values for the directly bonded coupling constants and long-range coupling constants are similar to those reported previously for other aromatic and aliphatic systems. Substituent effects on carbon-carbon coupling are compared for similarly substituted cyclic and acyclic systems. 相似文献
83.
Let Z = {Z0, Z1, Z2,…} be a martingale, with difference sequence X0 = Z0, Xi = Zi ? Zi ? 1, i ≥ 1. The principal purpose of this paper is to prove that the best constant in the inequality λP(supi |Xi| ≥ λ) ≤ C supiE |Zi|, for λ > 0, is C = (log 2)?1. If Z is finite of length n, it is proved that the best constant is . The analogous best constant Cn(z) when Z0 ≡ z is also determined. For these finite cases, examples of martingales attaining equality are constructed. The results follow from an explicit determination of the quantity Gn(z, E) = supzP(maxi=1,…,n |Xi| ≥ 1), the supremum being taken over all martingales Z with Z0 ≡ z and E|Zn| = E. The expression for Gn(z,E) is derived by induction, using methods from the theory of moments. 相似文献
84.
The UV absorption spectrum of acetylperoxy radicals, produced in several photochemical systems, has been investigated using the molecular modulation technique. Rate coefficients were determined at 28 and 715 Torr for the reaction CH3COO2 + NO2(+M) → CH3COO2NO2(+M), which exhibits a pressure dependence. 相似文献
85.
86.
Electron spin resonance has been observed for Fe3+ and Mn2+ ions occupying sites with trigonal symmetry in undoped and doped Verneuil-grown crystals of the ilmenite type compound MgTiO3. At 300 K, the fine structure parameters in the spin Hamiltonian are (in 10?4cm?1) D = +844 (± 1), (a? F) = +118 (± 1), a = 69 (± 7) for Fe3+ and D = +164 (± 1), (a ? F) = +10.2 (± l), a = 7.0 (± 1) for Mn2+. These values are compared with literature data for Fe3+ and Mn2+ in other oxides, especially Al2o3, with particular reference to the recent “superposition” theory of the effect of a trigonal distortion. From the orientation of the axes of cubic pseudosymmetry of the spin Hamiltonian, and with the assumption that a has the same sign for both ions, it is proposed that Fe3+ and Mn2+ occupy the same octahedral site, namely the Mg2+ site. Anomalous line splittings observed for one sample were attributed to twinning on (0001) or {1120} planes. 相似文献
87.
Diode laser spectroscopy has been employed to monitor the formation of chlorine nitrate (ClONO2) in the association reaction of ClO with NO2. Chlorine nitrate is the only stable end-product of this reaction at room temperature. Time-resolved measurements of ClONO2 formation using molecular modulation showed no evidence for any involvement of unstable isomers of ClNO3 in the reaction. These measurements gave a value of k1 = (1.8 ± 0.4) × 10?31 cm6/molecule2 · s for the reaction at 295 K and an upper limit of 5 ms for the lifetime of any isomeric products at this temperature. 相似文献
88.
The linear absorption of CO2 laser radiation in SF6, WF6, and UF6 has been measured by using optoacoustic detection techniques. Absolute absorption coefficients per Torr as low as 1 × 10?7 cm?1 Torr?1 in a 2-cm active path length could be measured by taking advantage of calibration measurements performed with SF6. 相似文献
89.
Lawrence E. Cox David M. Hercules 《Journal of Electron Spectroscopy and Related Phenomena》1973,1(3):193-207
X-ray photoelectron (ESCA) spectra of the core (Cl 2p K 2p and metal 4f, if present) and valence orbitals are reported for K2ReCl6, K2OsCl6, K2IrCl6· 3 H2O, K2PtCl6, K3MoCl6, and K2SnCl6. The K 2p binding energy was found to be nearly constant (292.7 eV) and that of Cl to increase very slightly with increasing atomic number for the third row transition metals. The chemical shifts of Re(IV), Os(IV), Ir(IV), and Pt(IV) relative to the metals were in qualitative agreement with atomic calculations utilizing configurations obtained from extended Hückel calculations. The valence spectra of the transition metal complexes exhibit a three-band structure. On the basis of MO results and intensity considerations the high binding energy band is assigned as a composite of the a1g, eg, 1t2g MO's. The middle band represents the t2u, 2t1g MO's; and the low binding energy band the 2t2g MO. Calculated nd orbital photoionization cross sections correlate reasonably well with the relative intensifies of the valence manifolds. Comparison of band separations and charge-transfer transition energies suggests that interelectronic repulsion and MO energy separation contribute about equally to the overall charge-transfer energy. 相似文献
90.