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61.
62.
Maria Teresa Rubino Dr. Mariangela Agamennone Dr. Cristina Campestre Dr. Giuseppe Fracchiolla Dr. Antonio Laghezza Dr. Fulvio Loiodice Prof. Elisa Nuti Dr. Armando Rossello Prof. Paolo Tortorella Prof. 《ChemMedChem》2009,4(3):352-362
Selective MMP inhibitors : Eleven α‐sulfonylphosphonates were synthesized and tested as MMP inhibitors. The IC50 values for most of them are in the nanomolar range against MMP‐2, ‐8, ‐13, and ‐14, with an interesting selectivity profile versus MMP‐9.
63.
Modeling Lac du Bonnet granite using a discrete element model 总被引:6,自引:0,他引:6
Yuannian Wang Fulvio Tonon 《International Journal of Rock Mechanics and Mining Sciences》2009,46(7):1124-1135
A discrete element method code developed by the authors is used to model Lac du Bonnet granite in triaxial compression. The paper first presents the features of the model and the algorithms used to identify the micro deformability and strength parameters. With these identification algorithms, the model was calibrated to match experimental triaxial test data on Lac du Bonnet granite. With the calibrated model, investigation on failure evolution was then performed. The monitored evolution of the number and type of contact failures (micro cracks) reveals that at micro level tensile failures occur first, followed by mobilization of residual friction. Three distinct stages of stress–strain curve can be well identified by the accumulated number of contact failures and the mode of contact failures. 相似文献
64.
Marilena Giangi Fulvio Stella Tomasz A. Kowalewski 《Computing and Visualization in Science》1999,2(2-3):123-130
A numerical and experimental study of unsteady natural convection during freezing of water is presented. The mathematical
model for the numerical simulations is based on the enthalpy-porosity method in vorticity-velocity formulation, equations
are discretised on a fixed grid by means of a finite volume technique. A fully implicit method has been adopted for the mass
and momentum equations. Experiments are performed for water in a differentially heated cube surrounded by air. The experimental
data for natural convection with freezing in the cavity are collected to create a reference for comparison with numerical
results. The method of simultaneous measurement of the flow and temperature fields using liquid crystal tracers is used. It
allows us to collect transient data on the interface position, and the temperature and velocity fields. In order to improve
the capability of the numerical method to predict experimental results, a conjugate heat transfer problem was solved, with
finite thickness and internal heat conductivity of the non-isothermal walls. These results have been compared with the simulations
obtained for the idealised case of perfectly adiabatic side walls, and with our experimental findings. Results obtained for
the improved numerical model shown a very good agreement with the experimental data only for pure convection and initial time
of freezing process. As time passes the discrepancies between numerical predictions and the experiment became more significant,
suggesting a necessity for further improvements of the physical model used for freezing water.
Received: 30 April 1999 / Accepted: 17 June 1999 相似文献
65.
A new direct HPLC method with fluorescence detection has been developed for the routine analysis of riboflavin, flavin mononucleotide and flavin-adenine dinucleotide, in wines and other beverages. These compounds are the main agents responsible for the "taste of light" that some white wines and other beverages develop when they are exposed to the light, due to the formation of sulfur compounds that produce an anion/garlic odor. A Hewlett-Packard 1100 gradient liquid chromatograph with 1046A fluorescence detector was used. To improve the selectivity, each compound was monitored to fit the best lambda excitation/lambda emission (265/525 nm). A 500 nm cut-off filter was used. The column was a Hypersil C18 ODS, 200 x 2.1 mm, 5 microns particle size. The volume injected was 20 microliters. A constant flow-rate of 0.6 ml/min was used with two solvents: solvent A, 0.05 M buffer NaH2PO4 at pH = 3.0 with H3PO4 and solvent B, acetonitrile. The precision, linearity and sensitivity of this method have been established. 相似文献
66.
Statistical Analysis of High-Resolution SAR Ground Clutter Data 总被引:4,自引:0,他引:4
This paper deals with the problem of modeling high-resolution synthetic aperture radar clutter data from different vegetated areas. We analyzed moving and stationary target recognition (MSTAR) data sets focusing on histograms, moments, and covariance of clutter amplitude, texture, and speckle. The most celebrated statistical models are tested on real data of grass field or wood and trees to validate the goodness of fit of the compound Gaussian model in different scenarios. The results demonstrate that for grass fields, the compound Gaussian model provides a good data fitting. This is not the case for woods images where the speckle is not more Gaussian distributed. Covariance analysis and concluding remarks complete this paper 相似文献
67.
The role of vitamin E in the protection against iron dependent lipid peroxidation was studied in rat liver microsomes and
Triton-dispersed microsomal lipid micelles. In these systems, an antioxidant effect of vitamin E at a physiological ratio
to phospholipids could be observed only in the presence of phospholipid hydroperoxide glutathione peroxidase (PHGPX) and glutathione.
The rationale of this cooperation is discussed on the basis of the hydroperoxyl radical scavenging capacity of vitamin E and
the reduction of membrane hydroperoxides by PHGPX. The scavenging of lipid hydroperoxyl radicals by vitamin E, although inhibiting
propagation of the peroxidative chain, produces lipid hydroperoxides from which ferrous iron generates alkoxyl radicals that
react with vitamin E almost as fast as with fatty acids. Therefore, only if membrane hydroperoxides are continuously reduced
by this specific peroxidase does the scavenging of hydroperoxyl radicals by vitamin E lead to an effective inhibition of lipid
peroxidation. 相似文献
68.
Perceived orientation of axis of rotation and accuracy in discriminating fixed-axis from nonfixed-axis rotations were investigated for orthographic projections of three-dimensional rotating objects. The principal findings were (1) the slant of the axis of rotation was systematically misperceived; (2) in both two-view and multiview displays, the perceived slant of the axis of rotation was well-predicted by the ratio between the deformation (a property of the first-order optic flow) and the component parallel to the image plane of the global velocity vector; (3) if this ratio was kept constant in each frame transition of the stimulus sequence (or it was varied), then the stimuli tended to be judged as fixed-axis rotations (or as nonfixed-axis rotations), regardless of whether they simulated a fixed-axis rotation or not; and (4) the tilt of the axis of rotation was perceived in two-view displays with a very small error. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
69.
Summary Structure of copolymers obtained by ring opening cationic polymerization from 7-oxabicyclo[ 2.2.1] heptane and ethylene oxide has been recently reported. This study about the spin lattice relaxation times and Nuclear Overhauser enhancement factor in the carbon-13 NMR spectra was performed and the results interpreted in terms of different internal mobility of the units in the copolymer chain.Previous papers in this series are: G. CECCARELLI, F.ANDRUZZI, Makromol. Chem. 180, 1371(1979); F.ANDRUZZI, G.CECCARELLI, M.PACI Polymer 21, 1180(1980); and ref (M.PACI et al. 1981). 相似文献
70.
Anelli PL Lattuada L Lorusso V Schneider M Tournier H Uggeri F 《Magma (New York, N.Y.)》2001,12(2-3):114-120
Mixed micelles for MRA are multicomponent systems containing a phospholipid, a biocompatible non-ionic surfactant (e.g. Synporonic(k) F-108) and a lipophilic gadolinium complex. A variety of lipophilic gadolinium complexes were designed taking into account
features such as: (i) nature of ligand (cyclic versus acyclic); (ii) lipophilic moiety; (iii) global charge of the complex;
and (iv) nature of bond connecting the complex to the lipophilic moiety. All the lipophilic gadolinium complexes after formulation
as mixed micelles show high relaxivities in water and in blood (rat). Mixed micelles containing gadolinium complexes bearing
only one aliphatic chain cannot be used as MRA contrast agents because they have a high haemolytic effect. Furthermore, in
rats they are quickly eliminated from the blood stream. These drawbacks are completely circumvented using gadolinium complexes
bearing two aliphatic chains. Mixed micelles containing such complexes show high relaxivities. no haemolytic effect and long
blood permanence. This makes them promising candidates as MRA contrast agents. However, elimination, which occurs exclusively
through the liver, is not complete, even after 7 days. Complexes containing labile (e.g. ester) bonds between the lipophilic
moieties and the chelate subunit are eliminated through both the liver and the kidneys. However, elimination is stiil not
complete after 7 days. 相似文献