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101.
Akira Takizawa Takao Negishi Kinzo Ishikawa 《Journal of polymer science. Part A, Polymer chemistry》1968,6(3):475-484
The influence of crystallinity on water sorption behavior by poly(vinyl alcohol) (PVA) was studied by using a PVA of low crystallinity (15% crystalline by x-ray analysis) and an annealed sample there from (46%) crystalline. With the increase of crystallinity, the sigmoid shape (which is a characteristic for the sorption isotherm of the low crystalline polymer) diminishes. The B.E.T. plots of the isotherms are linear between the relative vapor pressures of 0.1 and 0.4 as usual, and deviate from straight lines in the higher pressure range in the direction of a larger sorbed quantity than that predicted by the B.E.T. theory. This tendency is regarded as a kind of dissolution, and the Flory-Huggins interaction parameter χ1 was calculated. In both polymers, the χ1 versus pressure relation has a maximum, while overall χ1 values are smaller in the polymer of low crystallinity. The maximum point (which lies in the higher pressure region in case of the less crystalline sample) is considered to be a transition point from a phenomenon controlled mainly by an adsorption mechanism to a phenomenon controlled mainly by a dissolution mechanism. Accordingly, the separation of the isotherm into adsorption and a dissolution components was made, and the polymer fraction which contributes to the dissolution mechanism versus pressure relation was calculated. The result indicates that the crystalline region observed by x-ray analysis may partly contribute to the dissolution process at room temperature. 相似文献
102.
103.
An anisotropic three-dimensional neutron critical scattering has been observed from a “quasi” two-dimensional antiferromagnet MnTiO3 in the vicinity of the Néel temperature. When temperature increases, the scattering profile transforms gradually to a ridge-like form, indicating that “cross-over” from three-dimensional to two-dimensional character appears at about 16 degrees above TN. 相似文献
104.
105.
T. Ishikawa Y. Kurihara M. Skrzypek Z. Wąs 《The European Physical Journal C - Particles and Fields》1998,4(1):75-84
We discuss theoretical predictions for -pair production and decay at LEP2 and higher energies in a form suitable for comparison with raw data. We present a practical
framework for calculating uncertainties of predictions given by the KORALW and grc4f Monte Carlo programs. As an example we use observables in the decay channel: the total four-quark (four-jet) cross section and two-quark/jet invariant-mass distribution and cross section,
in the case when the other two may escape detection. Effects of QED bremsstrahlung, effective couplings, running and widths, Coulomb interaction and the complete tree level set of diagrams are discussed. We also revisit the question of technical
precision of the new version 1.21 of the KORALW Monte Carlo code as well as of version 1.2(26) of the grc4f one. Finally we find predictions of the two programs to have an overall physical uncertainty of 2%. As a side result we show,
on the example of an invariant mass distribution, the strong interplay of spin correlations and detector cut-offs in the case of four-fermion
final states.
Received: 18 March 1997 / Revised version: 4 July 1997 相似文献
106.
107.
E. V. Sampathkumaran K. Hirota I. Das M. Ishikawa 《Zeitschrift für Physik B Condensed Matter》1993,90(2):195-196
Experimental observations for possible presence of 4f quadrupolar Kondo effect in PrCu2Si2 are critically discussed. A comparison of the low temperature properties of the alloys, Pr
x
Y1–x
Cu2Si2 (x=0.05, 0.2 and 0.4), seems to signal the existence of 4f electric quadrupolar glass phenomenon around 4K forx=0.2. 相似文献
108.
K. Ishikawa H. Nakano H. Masuda C. Kusano Y. Takahashi T. Hamagishi N. Endo 《Fiber and Integrated Optics》1992,11(4):385-394
A 10-Gbit/s optical receiver is developed using low-capacitance HBT IC technology. The HBT allows a cutoff frequency of 45 GHz and a maximum oscillation frequency of 70 GHz. The receiver contains an automatic gain-control amplifier IC with a gain of 16 dB, a bandwidth of 10.7 GHz, and a decision-circuit IC with an ambiguity of 66 mVp-p at a data rate of 10 Gbit/s. The sensitivity of this receiver is -26.5 dBm at a bit error rate of 10-9. Transmission over a 140-km fiber was achieved successfully. 相似文献
109.
E. V. Sampathkumaran I. Das R. Vijayaraghavan A. Hayashi Y. Ueda M. Ishikawa 《Zeitschrift für Physik B Condensed Matter》1993,92(2):191-194
The temperature dependence of the lattice constants of the alloys, RCu2Ge2 (R=Nd, Tb, Dy, Ho and Tm) shows the existence of a lattice strain due to the alignment of the 4f-electric quadrupole at low temperatures. This strain could be related to the deviation of the Néel temperatures (T
N
) from that predicted by de Gennes scaling, thereby indicating the role of the quadrupole on the magnetism. On the other hand, in PrCu2Ge2, for which the enhancement ofT
N
is the largest in thisR series, the lattice constants interestingly behave as if the 4f-quadrupole moment is almost quenched and the anomalous magnetism in this case is attributed to some degree of 4f-delocalisation. 相似文献
110.
Shiro Ishikawa 《Fuzzy Sets and Systems》1998,100(1-3):291-300
Our main interest in this paper is to translate from “natural language” into “system theoretical language”. This is of course important since a statement in system theory can be analyzed mathematically or computationally. We assume that, in order to obtain a good translation, “system theoretical language” should have great power of expression. Thus we first propose a new frame of system theory, which includes the concepts of “measurement” as well as “state equation”. And we show that a certain statement in usual conversation, i.e., fuzzy modus ponens with the word “very”, can be translated into a statement in the new frame of system theory. Though our result is merely one example of the translation from “natural language” into “system theoretical language”, we believe that our method is fairly general. 相似文献