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In this paper, we introduce new approximate projection and proximal algorithms for solving multivalued variational inequalities involving pseudomonotone and Lipschitz continuous multivalued cost mappings in a real Hilbert space. The first proposed algorithm combines the approximate projection method with the Halpern iteration technique. The second one is an extension of the Halpern projection method to variational inequalities by using proximal operators. The strongly convergent theorems are established under standard assumptions imposed on cost mappings. Finally we introduce a new and interesting example to the multivalued cost mapping, and show its pseudomontone and Lipschitz continuous properties. We also present some numerical experiments to illustrate the behavior of the proposed algorithms.
相似文献Measurement precision and uncertainty estimation are important factors for all residual stress measurement techniques. The values of these quantities can help to determine whether a particular measurement technique would be viable option.
ObjectiveThis paper determines the precision of hole-drilling residual stress measurement using repeatability studies and develops an updated uncertainty estimator.
MethodsTwo repeatability studies were performed on test specimens extracted from aluminum and titanium shot peened plates. Each repeatability study included 12 hole-drilling measurements performed using a bespoke automated milling machine. Repeatability standard deviations were determined for each population. The repeatability studies were replicated using a commercially available manual hole-drilling milling machine (RS-200, Micro-Measurements). An updated uncertainty estimator was developed and was assessed using an acceptance criterion. The acceptance criterion compared an expected percentage of points (68%) to the fraction of points in the stress versus depth profile where the measured stresses ± its total uncertainty contained the mean stress of the repeatability studies.
ResultsBoth repeatability studies showed larger repeatability standard deviations at the surface that decay quickly (over about 0.3 mm). The repeatability standard deviation was significantly smaller in the aluminum plate (max ≈ 15 MPa, RMS?≈?6.4 MPa) than in the titanium plate (max ≈ 60 MPa, RMS?≈?21.0 MPa). The repeatability standard deviations were significantly larger when using the manual milling machine in the aluminum plate (RMS?≈?21.7 MPa), and for the titanium plate (RMS?≈?18.9 MPa).
ConclusionsThe single measurement uncertainty estimate met a defined acceptance criterion based on the confidence interval of the uncertainty estimate.
相似文献Background Uncertainty quantifications are required for any measurement result to be meaningful.
Objective The present work aims at deriving and comparing a priori estimates of displacement uncertainties in T3-stereocorrelation for a setup to perform high temperature tests.
Methods Images acquired prior to the actual experiment (i.e.,at room temperature) were registered using 3-noded triangular elements (T3-stereocorrelation) to determine displacement uncertainties for different positions of the experimental setup.
Results The displacement uncertainties were then compared to their a priori estimates.
Conclusions For the analyzed experiment, it is shown that noise floor estimates only differed by a factor 2 when compared to a posteriori measurements of standard displacement uncertainties.
相似文献Peel tests are frequently used to perform measurements of adhesive strength for pressure sensitive adhesive (PSA) tapes. Current lab methodologies for 90° peel tests translate the model substrate orthogonally to the peel direction in order to maintain the peel angle, precluding testing from immovable substrates.
ObjectiveIt was our objective to develop a peel fixture capable of testing temporary pavement marking (TPM) tapes and other PSA tapes from immovable substrates such as roadways surfaces.
MethodsWe present a modular peel fixture for conducting peel experiments directly on immovable substrates. The fixture was validated through a series of peel tests on consumer tapes to reproduce the linear width dependence and viscoelastic rate dependence found in traditional peeling setups. To test the capabilities of the fixture, a series of peel tests were conducted with various tapes on controlled surfaces, and a commercial tape on various immovable substrates.
ResultsWe demonstrate the ability of our fixture to reproduce results reported for traditional peel tests from literature. In addition, we were able to conduct peel tests directly on immovable substrates such as the benchtop.
ConclusionsThis fixture shows potential for both traditional peeling tests, and for use in in-situ peel experiments from substrates relevant to the end application of the PSA tape.
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