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141.
The chemisorption of CO on W(100) at ~ 100K has been studied using a combination of flash desorption and electron stimulated desorption (ESD) techniques. This is an extension of a similar study made for CO adsorption on W(100) at temperatures in the range 200–300K. As in the 200–300 K CO layer, both α1-CO and α2-CO are formed in addition to more strongly bound CO species upon adsorption at ~ 100K; the α-CO states yield CO+ and O+ respectively upon ESD. At low CO coverages, the α1 and α2-CO states are postulated to convert to β-CO or other strongly bound CO species upon heating. At higher CO coverages, α1-CO converts to α2-CO upon thermal desorption or electron stimulated desorption. There is evidence for the presence of other weakly-bound states in the low temperature CO layer having low surface concentration at saturation. The ESD behavior of the CO layer coadsorbed with hydrogen on W(100) is reported, and it is found that H(ads) suppresses either the concentration or the ionic cross section for α1 and α2-CO states. 相似文献
142.
The vapor phase absorption spectrum of thiophosgene (Cl2CS) in the 2500–2900 Å region consists of a broad intense band (. On the red side of this a vibrationally discrete structure is found which becomes increasingly diffuse and merges into the broad band as the wavelength is decreased. It is shown that this vibrational structure can be explained as due to a , electronic transition between a planar ground state and a pyramidal excited state of the molecule. In the latter state, the CS stretching mode ν1′(a1) = 681 cm?1 and the CCl bending mode ν3′(a1) = 147 cm?1. From the inversion doublet splitting of the out-of-plane mode ν4′(b1), the barrier to inversion is calculated to be ~126 cm?1, with an equilibrium out-of-plane angle of ~20°. 相似文献
143.
A. R. King 《Communications in Mathematical Physics》1974,38(2):157-171
The general solution of Einstein's equations for a stationary cylindrically symmetric distribution of pressure-free matter is obtained. It contains a function which may be freely prescribed. Using this freedom examples are given of new types of singularity in General Relativity. 相似文献
144.
The results of a vibrational and rotational analysis of the banded transition in are presented. Only three of the six vibrational modes are active in the spectrum with , , and . The spin forbidden transition gains intensity primarily by a mixing of the and states. This is confirmed by a rotational analysis of the 000 band of both isotopes. The rotational analysis shows that the coupling in the state is near Hund's case b and that the spin constants are nearly 10 times greater than those observed for CH2O. A calculation shows that this difference is due to the greater spin orbit coupling of S in CH2S and to the smaller energy differences between the , , , and the states. The r0 structure calculated from the rotational constants is , , βHCH = 119.6°, and α (out of plane) = 16.0°. A simultaneous fit of the vibrational levels in ν′4 of CH2S and CD2S to a double minimum potential function yielded a barrier to molecular inversion of 13 cm?1 and an equilibrium out-of-plane angle of 15°. 相似文献
145.
146.
James King Bidwell 《School science and mathematics》1966,66(7):661-669
147.
B. Pietrzyk R. Barate P. Bareyre P. Bonamy P. Borgeaud M. David F.X. Gentit G. Laurens Y. Lemoigne G. Villet S. Zaninotti P. Astbury A. Duane G.J. King B.C. Nandi R. Namjoshi D.M. Websdale J. Wiejak T. Marshall 《Physics letters. [Part B]》1982,113(1):105-112
A lepton-pair trigger was used to select a hadronic system in different flavour and colour states: properties of the transformation of this system into hadrons were measured in terms of charge flow, multiplicity distribution, and fragmentation function. It is observed that, while the effects of flavour are clearly seen, the colour degrees of freedom are not observed in the region of low pT. 相似文献
148.
H.H. Chang B.W. Ridley T.H. Braid T.W. Conlon E.F. Gibson N.S.P. King 《Nuclear Physics A》1978,297(1):105-124
The differential cross sections for the elastic scattering of 3He ions on targets of 40Ca and 58Ni have been measured at incident energies of 27.7, 51.4, 73.2 and 83.5 MeV. The results of optical model analyses showed that only one unique potential (JR ≈ 330 MeV · fm3) with a surface absorptive term can provide acceptable fits to the large angle elastic scattering cross sections at 83.5 MeV. The particular geometrical set found at 83.5 MeV could not, however, give an adequate fit to the data with energy less than 40 MeV. Subsequent analyses indicated that a break in the energy dependence of the real potential is observed for the low energy data. Explicit energy dependent terms were obtained by fitting all the data simultaneously. These phenomenological potentials were also compared with the folded nucleon-nucleus potential. The influence of the α-particle channels on the elastic scattering of 3He ions at 83.5 MeV was also examined. 相似文献
149.
A very low-pressure pyrolysis (VLPP) apparatus has been constructed and shown to yield kinetic data consistent with other VLPP systems. The technique has been applied to the pyrolysis of cyclobutyl cyanide over the temperature range of 833–1203°K. The reaction was found to proceed via a single pathway to yield ethylene and vinyl cyanide. If A∞ is based on previous high-pressure data for this reaction and for cyclobutane pyrolysis, then RRKM theory calculations show that the experimental unimolecular rate constants are consistent with the high-pressure Arrhenius parameters given by where θ=2.303 RT in kcal/mole. If A∞ is adjusted relative to the more recent parameters for cyclobutane pyrolysis suggested by VLPP studies, then the Arrhenius expression becomes The cyano group reduces the activation energy for cyclobutane pyrolysis by 6±1 kcal/mole, and on the basis of a biradical mechanism this value may be attributed to the cyano stabilization energy. 相似文献
150.
T. C.?King Y. K.?KuoEmail author 《The European Physical Journal B - Condensed Matter and Complex Systems》2005,45(4):515-521
The small-size partially filled one-dimensional (1D) lattice gas system with
1/rδ repulsive interactions is numerically studied. Our results
indicate that phase change with vacancy ordering involved exists in the
partially filled 1D lattice gas systems, and the phase properties of the
studied system strongly depend on the occupancy nav and the interaction
strength δ. Most interestingly, it is found that the phase change
still exists in the 1D finite-size lattice gas systems even with nearest
neighbor interactions, i.e. δ is infinite. These results provide
valuable information about the phase properties of 1D confined systems, such
as molecules inside the carbon nanotubes, with long-range interactions
between particles. 相似文献