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991.
This paper deals with the mathematical modeling of the mammary carcinoma-immune system competition elicited by an external stimulus represented by three different protocols of the triplex vaccine [C. De Giovanni, et al., Immunoprevention of HER-2/neu transgenic mammary carcinoma through an interleukin 12-engineered allogeneic cell vaccine, Cancer Research 64 (2004) 4001-4009]. The presented model is composed of nonlinear ordinary differential equations based on parameters and cell populations. A qualitative analysis of the asymptotic behavior of the model and numerical simulations are able to depict preclinical experiments on transgenic mice in tune with the SimTriplex model [F. Pappalardo, F. Castiglione, P.L. Lollini, S. Motta, Modelling and simulation of cancer immunoprevention vaccine, Bioinformatics 21 (2005) 2891-2897]. The results are of great interest both in the applied and theoretical sciences. 相似文献
992.
Thomas Désaunay Armelle Ringuedé Michel Cassir Frédéric Labat Carlo Adamo 《Surface science》2012,606(3-4):305-311
In this paper, the structural and electronic properties of CeO2 are studied using conventional and hybrid density functional theory. A computational protocol, based on the parameter-free hybrid functional PBE0 coupled with a 4f in-valence basis set for Ce atoms based on a 28 electrons small core pseudopotential is able to reasonably reproduce both structural and electronic experimental data. Such a protocol is then applied to the modeling of true 2-D periodic CeO2 slabs of non polar low-index surfaces. The obtained results show that the (111) surface is more stable than the (110) one (0.73 vs 0.81 J/m2), with a substantial rumbling in the outermost planes of this latter. Finally, as a first step toward reactivity at CeO2 surfaces involved in solid oxide fuel cells, the importance of electrostatic effects in the adsorption of chemical species such as CO is presented. These results will allow for a detailed study of catalytic reactions at ceria surface. 相似文献
993.
Carlo Cafaro Salvatore Capozziello Stefano Mancini 《International Journal of Theoretical Physics》2012,51(8):2313-2340
We study special relativistic effects on the entanglement between either spins or momenta of composite quantum systems of two spin- \frac12\frac{1}{2} massive particles, either indistinguishable or distinguishable, in inertial reference frames in relative motion. For the case of indistinguishable particles, we consider a balanced scenario where the momenta of the pair are well-defined but not maximally entangled in the rest frame while the spins of the pair are described by a one-parameter (η) family of entangled bipartite states. For the case of distinguishable particles, we consider an unbalanced scenario where the momenta of the pair are well-defined and maximally entangled in the rest frame while the spins of the pair are described by a one-parameter (ξ) family of non-maximally entangled bipartite states. In both cases, we show that neither the spin-spin (ss) nor the momentum-momentum (mm) entanglements quantified by means of Wootters’ concurrence are Lorentz invariant quantities: the total amount of entanglement regarded as the sum of these entanglements is not the same in different inertial moving frames. In particular, for any value of the entangling parameters, both ss and mm-entanglements are attenuated by Lorentz transformations and their parametric rates of change with respect to the entanglements observed in a rest frame have the same monotonic behavior. However, for indistinguishable (distinguishable) particles, the change in entanglement for the momenta is (is not) the same as the change in entanglement for spins. As a consequence, in both cases, no entanglement compensation between spin and momentum degrees of freedom occurs. 相似文献
994.
Carlo Lancia Francesca R. Nardi Benedetto Scoppola 《Journal of statistical physics》2012,149(1):108-141
In this paper we present, in the context of Diaconis’ paradigm, a general method to detect the cutoff phenomenon. We use this method to prove cutoff in a variety of models, some already known and others not yet appeared in literature, including a non-reversible random walk on a cylindrical lattice. All the given examples clearly indicate that a drift towards the opportune quantiles of the stationary measure could be held responsible for this phenomenon. In the case of birth-and-death chains this mechanism is fairly well understood; our work is an effort to generalize this picture to more general systems, such as systems having stationary measure spread over the whole state space or systems in which the study of the cutoff may not be reduced to a one-dimensional problem. In those situations the drift may be looked for by means of a suitable partitioning of the state space into classes; using a statistical mechanics language it is then possible to set up a kind of energy-entropy competition between the weight and the size of the classes. Under the lens of this partitioning one can focus the mentioned drift and prove cutoff with relative ease. 相似文献
995.
996.
ABSTRACT Optimal design problems for flexural systems with a nonlinear constitutive law are considered, in the presence of constraints on displacements. A general nonlinear holonomic moment-curvature relationship is assumed and a direct variational method is applied in order to obtain optimality criteria. Accordingly, a general method of solution is proposed and some examples are solved. 相似文献
997.
F. S. Manciu J. R. Govani W. G. Durrer L. Reza L. A. Pinales 《Journal of Raman spectroscopy : JRS》2009,40(8):861-865
Although herbal medicine is widely employed in inhibition of urinary calculi as an alternative and complementary curative method, the lack of detailed scientific studies that could provide insights into this complex process weakens its validity. The present work targets multitechnique spectroscopic investigations by Raman, infrared absorption, X‐ray photoelectron spectroscopy (XPS), and photoluminescence on the effects of the herb Rotula Aquatica Lour (RAL) on the growth of synthetically prepared magnesium‐based calculi. In addition to the standard magnesium phosphate‐based sample, two other samples were prepared with incorporation of 1 and 2wt% RAL herbal extract. Both, Raman and infrared data show a newberyite structure for the crystals without and with inhibitor. The XPS measurements reveal an unexpected presence of Zn in the sample with bfRAL inhibitor, which, as suggested in the literature, may initiate rapid stone formation, and consequently, contribute to the inhibition process. Furthermore, the existence of metallic Zn can explain the reflectance of the incident light observed in the infrared transmission studies of the unground crystals. A significant increase in magnesium with addition of herbal extract is observed in the XPS data. Also, evidence for Mg O binding between the inhibitor and the phosphate units of urinary calculus is found in XPS and Raman results. Similarity between our photoluminescence measurements and those of in vivo chlorophyll a corroborates to provide additional evidence of Mg‐related inhibition. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
998.
Alberto Casu Pier Carlo Ricci Alberto Anedda 《Journal of Raman spectroscopy : JRS》2009,40(9):1224-1228
Lutetium yttrium orthoaluminate perovskite [Lu0.7Y0.3AlO3 (LuYAP)] crystals show great potential as fast response and high‐efficiency scintillators as an alternative to LuAlO3 (LuAP) crystals. This paper aims to offer a complete analysis of the vibrational modes of the LuYAP crystal by means of polarized Raman spectroscopy in the temperature range of 20–290 K and confronting the experimental results with numerical methods in order to characterize the crystal structure. Furthermore, an interpretation of the data in terms of vibrating molecular structures is suggested and the results are successfully confronted with the vibrational modes of similar perovskite crystals. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
999.
Francesca Benuzzi Fausta Lui Davide Duzzi Paolo F. Nichelli Carlo Adolfo Porro 《Magnetic resonance imaging》2009
The neural mechanisms subserving recognition of noxious stimuli and empathy for pain appear to involve at least in part the cortical regions associated with the processing of pain affect. An important issue concerns the specificity of brain networks associated with observing and representing painful conditions, in comparison with other unpleasant stimuli. Recently, we found both similarities and differences between the brain patterns of activity related to the observation of noxious or disgusting stimuli delivered to one hand or foot. Overlap regions included the perigenual anterior cingulate (pACC), whose activity was related to the perceived unpleasantness. We aimed here at revealing how pACC functional connectivity changes in relationship to the different experimental conditions, using a psychophysiological interaction model. Activity in pACC during the observation of painful stimuli was specifically and positively related to regions in the right hemisphere, including portions of the prefrontal, midcingulate and insular cortex. On the other hand, positive changes in pACC connectivity during the vision of disgusting stimuli were present in the right basal ganglia. These data suggest that pACC activity is part of different networks involved in the recognition of painful or disgusting stimuli. 相似文献
1000.
Evaluation of volatile chlorinated hydrocarbons distribution along depth profiles in the Ross Sea, Antarctica 总被引:1,自引:0,他引:1
The presence and the distribution along depth profiles of volatile chlorinated hydrocarbons (VCHCs) were evaluated in seawater samples collected in the Ross Sea (Southern Ocean, Antarctica) during the 2002-2003 Italian expedition. Sampling areas were located where the Circumpolar Deep Water interacts with the shelf waters that supply the Ross Sea.The VCHCs investigated were: 1,1,1-trichloroethane (C2H3Cl3), tetrachloromethane (CCl4), trichloroethylene (C2HCl3), tetrachloroethylene (C2Cl4). The analytical procedure consisted of a liquid-liquid extraction carried out with n-hexane directly in Antarctica, followed by gas chromatographic analysis with electron capture detection carried out in Italy.Concentration levels for the VCHCs analysed ranged from digits to hundreds of ng/L according to the station, depth and substance considered. Important differences in concentration levels between the three stations near the Ross Ice Shelf and the two stations located in the Cape Adare area were observed. In particular the stations situated in the Cape Adare zone, at certain depths, showed a thermal inversion due to the mixing of the Circumpolar Deep Water with the waters generated inside the Ross Sea Basin. The lowest concentration levels were recorded at this temperature increase. 相似文献