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161.
R. Hari A. Antervo T. Katila T. Poutanen M. Seppänen T. Tuomisto T. Varpula 《Il Nuovo Cimento D》1983,2(2):484-494
Summary Voluntary limb movements are preceded by MEG shifts beginning even as early as 1.2 s before the movement. These shifts reverse
polarity above the cortical motor representation area of the limb concerned.
Preliminary reports of this study have been presented (1,2). 相似文献
162.
Ohlsson J Larsson A Haataja S Alajääski J Stenlund P Pinkner JS Hultgren SJ Finne J Kihlberg J Nilsson UJ 《Organic & biomolecular chemistry》2005,3(5):886-900
Four collections of Gal alpha1-4Gal derivatives were synthesised and evaluated as inhibitors of the PapG class II adhesin of uropathogenic Escherichia coli and of the P(N) and P(O) adhesins of Streptococcus suis strains. Galabiosides carrying aromatic structures at C1, methoxyphenyl O-galabiosides in particular, were identified as potent inhibitors of the PapG adhesin. Phenylurea derivatisation at C3' and methoxymethylation at O2' of galabiose provided inhibitors of the S. suis strains type P(N) adhesin with remarkably high affinities (30 and 50 nM, respectively). In addition, quantitative structure-activity relationship models for E. coli PapG adhesin and S. suis adhesin type P(O) were developed using multivariate data analysis. The inhibitory lead structures constitute an advancement towards high-affinity inhibitors as potential anti-adhesion therapeutic agents targeting bacterial infections. 相似文献
163.
Identification of the hydrolysis products of AlCl3.6H2O by electrospray ionization mass spectrometry
Sarpola A Hietapelto V Jalonen J Jokela J Laitinen RS 《Journal of mass spectrometry : JMS》2004,39(4):423-430
The hydrolysis reactions of AlCl3 in 0.1 M aqueous solutions at pH 3.27-4.20 were monitored by electrospray ionization time-of-flight mass spectrometry (ESI-ToF MS) as a function of time. The cationic and anionic ESI mass spectra of aluminum(III) solutions gave strong evidence of the presence of a variety of monomeric and polymeric complexes. Competition between the OH- and Cl- ligands within the same aluminum core was observed. The influence of the sample cone voltage on the product distribution was also explored. The optimum sample cone voltage for the cationic spectra was 70 V. For the anionic spectra no optimum sample cone voltage was found and the appearance of the anionic spectra was strongly dependent on the sample cone voltage within the whole range explored. 相似文献
164.
129Xe NMR spectra of xenon dissolved in acetonitrile confined into three mesoporous silica gels with nominal pore diameters of 40, 60, and 100 A have been measured over the temperature range 170-245 K. The spectra consist of a number of lines, which contain detailed information on the system. The most interesting result is that the chemical shift of a particular signal observed below the melting point of confined acetonitrile is highly sensitive to the pore size, and hence its shape is sensitive to the pore size distribution function. This signal originates from the xenon atoms sited in very small cavities built up inside the pores during the freezing transition. It can be used to determine the size or even the size distribution function of the pores. In addition, the emergence of this signal reveals the phase transition temperature of acetonitrile inside the pores, which can also be used to determine the size of the pores. The difference in the chemical shifts of two other signals, which arise from xenon dissolved in bulk and confined acetonitrile, provides still another novel method for determining the size of the pores. 相似文献
165.
Lantto P Vaara J Kantola AM Telkki VV Schimmelpfennig B Ruud K Jokisaari J 《Journal of the American Chemical Society》2002,124(11):2762-2771
Rovibrational corrections, temperature dependence, and secondary isotope shifts of the (13)C nuclear shielding in CX(2) (X = O, S, Se, Te) are calculated taking into account the relativistic spin-orbit (SO) interaction. The SO effect is considered for the first time for the secondary isotope shifts. The nuclear shielding hypersurface in terms of nuclear displacements is calculated by using a density-functional theory method. Ab initio multiconfiguration self-consistent field calculations are done at the equilibrium geometry for comparison. (13)C NMR measurements are carried out for CS(2). The calculated results are compared with both present and earlier experimental data on CO(2), CS(2), and CSe(2). The heavy-atom SO effects on the rovibrational corrections of (13)C shielding are shown to be significant. For CSe(2) and CTe(2), reliable prediction of secondary isotope effects and their temperature dependence requires the inclusion of the SO corrections. In particular, earlier discrepancies of theory and experiment for CSe(2) are fully resolved by taking the SO interactions into account. 相似文献
166.
Jukka Saranen 《manuscripta mathematica》1977,20(4):355-376
In this paper we prove the existence and uniqueness of a solution u satisfying the equation- u – k2 y = f (k , k 0), homogeneous Dirichlet data on the boundary and a radiation condition at infinity. We consider this problem in some unbounded region with an infinite boundary for which the assumption (x) · (x) 0 holds; here denotes the exterior normal and a given field. 相似文献
167.
J. H. Blanke B. Fricke D. Heinemann W-D Sepp B. Thies T. Göbenli P. H. Heckmann G. Möller E. Träbert 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1989,13(1):1-7
We present the first observation of optical transitions between doubly excited doublet states in the term systems N V, O VI and F VII. The spectra were produced by foil excitation of fast ion beams. The assignment of the spectral lines was made by comparison with the results of MCDF calculations along the isoelectronic sequence. The same method also led to the identification of two 3d – 4f quartet transitions in Mg X. 相似文献
168.
Nicos Georgiou Firas Rassoul-Agha Timo Seppäläinen 《Communications in Mathematical Physics》2016,346(2):741-779
We discuss variational formulas for the law of large numbers limits of certain models of motion in a random medium: namely, the limiting time constant for last-passage percolation and the limiting free energy for directed polymers. The results are valid for models in arbitrary dimension, steps of the admissible paths can be general, the environment process is ergodic under spatial translations, and the potential accumulated along a path can depend on the environment and the next step of the path. The variational formulas come in two types: one minimizes over gradient-like cocycles, and another one maximizes over invariant measures on the space of environments and paths. Minimizing cocycles can be obtained from Busemann functions when these can be proved to exist. The results are illustrated through 1+1 dimensional exactly solvable examples, periodic examples, and polymers in weak disorder. 相似文献
169.
Henrik Nyman Jie Xiong Johan Pensar Jukka Corander 《Advances in Data Analysis and Classification》2016,10(3):305-326
An inductive probabilistic classification rule must generally obey the principles of Bayesian predictive inference, such that all observed and unobserved stochastic quantities are jointly modeled and the parameter uncertainty is fully acknowledged through the posterior predictive distribution. Several such rules have been recently considered and their asymptotic behavior has been characterized under the assumption that the observed features or variables used for building a classifier are conditionally independent given a simultaneous labeling of both the training samples and those from an unknown origin. Here we extend the theoretical results to predictive classifiers acknowledging feature dependencies either through graphical models or sparser alternatives defined as stratified graphical models. We show through experimentation with both synthetic and real data that the predictive classifiers encoding dependencies have the potential to substantially improve classification accuracy compared with both standard discriminative classifiers and the predictive classifiers based on solely conditionally independent features. In most of our experiments stratified graphical models show an advantage over ordinary graphical models. 相似文献
170.
Branderhorst HM Kooij R Salminen A Jongeneel LH Arnusch CJ Liskamp RM Finne J Pieters RJ 《Organic & biomolecular chemistry》2008,6(8):1425-1434
A galabiose disaccharide building block was synthesized by an efficient pectinase cleavage of polygalacturonic acid and subsequent chemical functional group transformations. Besides the disaccharide, the corresponding trisaccharide was also obtained and modified. The compounds were subsequently conjugated to dendrimers with up to eight end groups using 'click' chemistry. The compounds were evaluated as inhibitors of adhesion of the pathogen Streptococcus suis in a hemagglutination assay and strong inhibition was observed for the tetra- and octavalent galabiose compound with MIC values in the low nanomolar range. The corresponding octavalent trisaccharide was a ca. 20-fold weaker inhibitor. 相似文献